Patent Description:
A transport climate control system can include, for example, a transport refrigeration system (TRS) and/or a heating, ventilation and air conditioning (HVAC) system. A TRS is generally used to control an environmental condition (e.g., temperature, humidity, air quality, and the like) within a cargo space of a transport unit (e.g., a truck, a container (such as a container on a flat car, an intermodal container, etc.), a box car, a semi-tractor, a bus, or other similar transport unit). The TRS can maintain environmental condition(s) of the cargo space to maintain cargo (e.g., produce, frozen foods, pharmaceuticals, etc.). In some embodiments, the transport unit can include a HVAC system to control a climate within a passenger space of the vehicle.

A power system can be used to power a transport climate control system, stationary equipment (such as a construction lift), etc. A power system can be used to provide power when a utility power source (e.g., power grid, shore power, etc.) is not available such as, for example, during transport.

<CIT> discloses methods and systems for controlling an energy source for a mild hybrid system that powers a transport climate control system. The mild hybrid system includes a DC energy source configured to supply a first DC voltage to the transport climate control system. The system also includes an inverter connected to the DC energy source and configured to change the first DC voltage from the DC energy source to a first AC voltage. The system further includes a transformer connected to the inverter and configured to convert the first AC voltage to a second AC voltage. Also the system includes a motor that drives a compressor. The motor is driven by the second AC voltage, the second AC voltage is greater than the first AC voltage.

<CIT> discloses an apparatus for preconditioning an interior of a non-electric vehicle which uses power supplied from a source external to the vehicle, such as a power grid. The non-electric vehicle includes an engine, a battery, and an electric machinepower plant that supplies electrical energy to the battery when driven by the engine. An AC/DC converter is configured to receive electrical energy from an external source and to supply such electrical energy through the battery to power the electric machine power-plant to drive the mechanically operated air conditioner when the engine is not operating.

The embodiments described herein provide a direct drive powertrain whereby a prime mover (e.g., an internal combustion engine), a motor-generator, and load(s) (e.g., a transport climate control system compressor) are all in line with each other. By using a direct drive powertrain to the load(s), power efficiency losses due to a belt-drive or due to electrical to mechanical power conversion can be avoided.

The embodiments described herein provide a direct drive parallel architecture that integrates a prime mover and an electric motor to both provide power via a drive shaft to load(s). Each of the prime mover and the electric motor can provide shaft power to the load(s) separately or together.

The embodiments described herein provide a direct drive parallel power system that can support maximum power requirements from load(s) (e.g., a transport climate control system) while reducing the size of a prime mover of the power system that may be more efficient at supplying a lower power requirement to the load(s). Accordingly, fuel efficiency of the power system of the power system can be increased.

The embodiments described herein can also provide increased fuel efficiency by allowing the power system to provide power from a battery source and inactivating operation (e.g., shut off, power off, turn off, etc.) of the prime mover.

In some embodiments, a prime mover of the direct drive parallel power system can be a small internal combustion engine (e.g., an internal combustion engine that supplies less than <NUM> kilowatts of mechanical power). At low loads (e.g., when the direct drive parallel powers system is not powering a compressor), a small internal combustion engine can run at a higher fuel efficiency and can avoid running at a low exhaust temperature (e.g., below <NUM>° C) as compared to a large internal combustion engine (e.g., an internal combustion engine that supplies <NUM> kilowatts or greater of mechanical power). A small internal combustion engine can also require fewer emissions control components, be cheaper in price, have a lower weight, and a smaller physical size as compared to a large internal combustion engine. This can offset additional costs associated with the direct drive parallel power system including a motor-generator, a battery source, etc..

It will be appreciated that in some embodiments, a transport climate control system generally goes through stages requiring more than <NUM> kilowatts of power for a short period of time followed by a longer period of time requiring less than <NUM> kilowatts of power. In some embodiments, the direct drive parallel power system can use a small internal combustion engine (e.g., an internal combustion engine that supplies less than <NUM> kilowatts of mechanical power) while still supplying more than <NUM> kilowatts of power by using a motor-generator to supply mechanical power and/or a battery source to supply electrical power to supplement the small internal combustion engine. Accordingly, the embodiments described herein can meet, for example, Environmental Protection Agency (EPA) and CARB Final Tier <NUM> and/or European Non-Road Mobile Machinery (NRMM) emissions standards (including, for example, Stationary Operating Time Limit (SOTL) regulations, Zero Emission Mode Operating Time (ZEMOT) regulations, etc.) for transport climate control systems that require a less than <NUM> kilowatt diesel engine or a costly high complexity internal combustion engine (e.g., an internal combustion engine that requires one or more of a high cost fuel system, a full electronic engine management system, an exhaust gas recirculation (EGR) and/or diesel oxidation catalyst (DOC) aftertreatment systems, meets particulate value requirements, a diesel particulate filter (DPF), etc.). In the embodiments described herein, the direct drive parallel power system can charge a battery source during stages when less than <NUM> kilowatts are demanded from the transport climate control system so that the battery source can supply power to the transport climate control system when the transport climate control system is demanding more than <NUM> kilowatts of power.

In some embodiments, the direct drive parallel power system can be used to drive a mechanically driven compressor, particularly a direct drive compressor. In particular, a motorgenerator can be provided between a prime mover and the direct drive compressor along a drive shaft. In some embodiments, a clutch can also be provided between the prime mover and the motor-generator to allow the prime mover to be deactivated while allowing the motor-generator to mechanically power (e.g., rotate) the direct drive compressor. An advantage of using a mechanically driven compressor is that it is not limited to certain speeds of operation or require a variable frequency drive as is the case with an electrically driven compressor. Also, the mechanically driven compressor can operate at lower speeds such that an electronic throttle valve (ETV) or other modulation valve is not needed to throttle back working fluid passing through a climate control circuit of the transport climate control system. Thus, the mechanically driven compressor can operate efficiently during modulation temperature control conditions (e.g., conditions when the climate control circuit is not desired to be operating at a full climate control capacity (e.g., cooling capacity)such as when the temperature within the climate controlled space is at or near a desired setpoint temperature within the climate controlled space) by modifying the speed of the mechanically driven compressor to control climate control capacity (e.g., cooling capacity) rather than using the ETV or other modulation valve.

The direct drive parallel power system described in the embodiments herein can provide cost, volume (e.g., space, and weight) advantages over a fully electric power system while maintaining and/or exceeding an operating range over the fully electric power system.

In one embodiment, a direct drive parallel power system for powering a transport climate control system is provided. The direct drive parallel power system includes a powertrain, a battery source and a power system controller. The powertrain includes a prime mover, a motorgenerator, and a drive shaft. The prime mover is configured to generate mechanical power for powering a direct driven load of the transport climate control system via the drive shaft. The motor-generator includes a motor and a generator. The motor is configured to generate mechanical power for powering the direct driven load via the drive shaft. The battery source is electrically connected to the generator of the motor-generator. The battery source is configured to supply electrical power to the motor of the motor-generator and configured to supply electrical power to an electrically driven load of the transport climate control system. The power system controller is configured to monitor and control operation of the prime mover, the motorgenerator, and the battery source. The power system controller is configured to operate the direct drive parallel power system in a parallel operation mode in which both the prime mover and the motor-generator are instructed to concurrently supply mechanical power via the drive shaft to the direct driven load.

In another embodiment, a method for operating the direct drive parallel power system to power a transport climate control system is provided. The method includes monitoring a prime mover parameter and comparing the monitored prime mover parameter to a prime mover threshold. When the monitored prime mover parameter is less than the prime mover threshold, operating the direct drive parallel power system in the parallel operation mode to power the direct driven load of the transport climate control system. When the monitored prime mover parameter is not less than the prime mover threshold, operating the direct drive parallel power system in a prime mover operation mode to power the direct driven load.

References are made to the accompanying drawings that illustrate embodiments of the invention.

A transport climate control system is generally used to control one or more environmental conditions such as, but not limited to, temperature, humidity, air quality, or combinations thereof, of a transport unit. Examples of transport units include, but are not limited to a truck, a container (such as a container on a flat car, an intermodal container, a marine container, a rail container, etc.), a box car, a semi-tractor, a passenger vehicle, or other similar transport unit. A climate controlled transport unit can be used to transport perishable items such as pharmaceuticals, produce, frozen foods, and meat products and/or can be used to provide climate comfort for passengers in a passenger space of a passenger vehicle. The transport climate control system may include a vapor-compressor type climate controlled system, a thermal accumulator type system, or any other suitable climate controlled system that can use a working fluid (e.g., refrigerant, etc.), cold plate technology, or the like.

A transport climate control system can include a climate control unit (CCU) attached to a transport unit to control one or more environmental conditions (e.g., temperature, humidity, air quality, etc.) of a climate controlled space of the climate controlled transport unit. The CCU can include, without limitation, a climate control circuit (including, for example, a compressor, a condenser, an expansion valve, and an evaporator), and one or more fans or blowers to control the heat exchange between the air within the climate controlled space and the ambient air outside of the climate controlled transport unit.

In some embodiments, the power system can be a generator set. A generator set ("genset") generally includes the combination of a prime mover (e.g., an engine such as an internal combustion engine like a diesel engine) with an electrical machine (e.g., a generator) that can be used to generate electrical power. As described in more detail below, a generator set can also include a battery source that can also be used to generate electrical power. A genset can be used to power one or more loads (e.g., a transport climate control system) when a utility power source is unavailable.

<FIG> show various transport climate control systems. It will be appreciated that the embodiments described herein are not limited to the examples provided below, but can apply to any type of transport unit (e.g., a truck, a container (such as a container on a flat car, an intermodal container, a marine container, etc.), a box car, a semi-tractor, a passenger bus, or other similar transport unit), etc..

<FIG> illustrates one embodiment of a climate controlled transport unit <NUM> attached to a tractor <NUM>. The climate controlled transport unit <NUM> includes a climate control system <NUM> for a transport unit <NUM>. The tractor <NUM> is attached to and is configured to tow the transport unit <NUM>. The transport unit <NUM> shown in <FIG> is a trailer.

The transport climate control system <NUM> includes a climate control unit (CCU) <NUM> that provides environmental control (e.g. temperature, humidity, air quality, etc.) within a climate controlled space <NUM> of the transport unit <NUM>. The climate control system <NUM> also includes a programmable climate controller <NUM> and one or more sensors (not shown) that are configured to measure one or more parameters of the climate control system <NUM> (e.g., an ambient temperature outside of the transport unit <NUM>, a space temperature within the climate controlled space <NUM>, an ambient humidity outside of the transport unit <NUM>, a space humidity within the climate controlled space <NUM>, etc.) and communicate parameter data to the climate controller <NUM>.

The transport climate control system <NUM> can operate in multiple operation modes including, for example, a continuous cooling mode, a start/stop cooling mode, a heating mode, a defrost mode, a null mode, etc. When operating in a continuous cooling mode and/or a start-stop cooling mode, the transport climate control system <NUM> can operate in a pulldown setting and in a steady-state setting. The pulldown setting generally occurs when, for example, the climate controlled space <NUM> is being cooled from an ambient temperature down to a desired set-point temperature so that the transport climate control system <NUM> can bring the temperature down to the desired set-point temperature as quickly as possible. The steady-state setting generally occurs when, for example, the climate in the climate controlled space <NUM> has already reached or is close to approaching a desired set-point temperature and the transport climate control system <NUM> is working to maintain the desired set-point temperature.

The CCU <NUM> is disposed on a front wall <NUM> of the transport unit <NUM>. In other embodiments, it will be appreciated that the CCU <NUM> can be disposed, for example, on a rooftop or another wall of the transport unit <NUM>. The CCU <NUM> includes a transport climate control circuit (not shown) that connects, for example, a compressor, a condenser, an evaporator and an expander (e.g., expansion valve) to provide conditioned air within the climate controlled space <NUM>.

The climate controller <NUM> may comprise a single integrated control unit <NUM> or may comprise a distributed network of climate controller elements <NUM>, <NUM>. The number of distributed control elements in a given network can depend upon the particular application of the principles described herein. The climate controller <NUM> is configured to control operation of the climate control system <NUM> including the transport climate control circuit.

The climate control system <NUM> is powered by a power system that can distribute power to the climate control system <NUM> when a utility power source is unavailable. In some embodiments, the power system can be housed within the CCU <NUM>. In some embodiments, the power system can be a generator set (not shown) attached to the transport unit <NUM> and connected to one or more components of the climate control system <NUM> (e.g., a compressor, one or more fans and/or blowers, the climate controller <NUM>, one or more sensors, etc.). the power system can is a direct drive parallel power system as discussed in further detail below with respect to <FIG>, <FIG> and 3A and 3B.

<FIG> is a side view of a truck <NUM> with a transport climate control system <NUM>, according to an embodiment. The truck <NUM> includes a climate controlled space <NUM> for carrying cargo. The transport climate control system <NUM> includes a CCU <NUM> that is mounted to a front wall <NUM> of the climate controlled space <NUM>. The CCU <NUM> can include, among other components, a climate control circuit (not shown) that connects, for example, a compressor, a condenser, an evaporator, and an expander (e.g., expansion valve) to provide climate control within the climate controlled space <NUM>. In an embodiment, the CCU <NUM> can be a transport refrigeration unit.

The transport climate control system <NUM> also includes a programmable climate controller <NUM> and one or more climate control sensors (not shown) that are configured to measure one or more parameters of the transport climate control system <NUM> (e.g., an ambient temperature outside of the truck <NUM>, an ambient humidity outside of the truck <NUM>, a compressor suction pressure, a compressor discharge pressure, a supply air temperature of air supplied by the CCU <NUM> into the climate controlled space <NUM>, a return air temperature of air returned from the climate controlled space <NUM> back to the CCU <NUM>, a humidity within the climate controlled space <NUM>, etc.) and communicate climate control data to the climate controller <NUM>. The one or more climate control sensors can be positioned at various locations outside the truck <NUM> and/or inside the truck <NUM> (including within the climate controlled space <NUM>).

The climate controller <NUM> is configured to control operation of the transport climate control system <NUM> including components of the climate control circuit. The climate controller <NUM> may include a single integrated control unit or may include a distributed network of climate controller elements (not shown). The number of distributed control elements in a given network can depend upon the particular application of the principles described herein. The measured parameters obtained by the one or more climate control sensors can be used by the climate controller <NUM> to control operation of the climate control system <NUM>.

The climate control system <NUM> is powered by a power system that can distribute power to the climate control system <NUM> when a utility power source is unavailable. In some embodiments, the power system can be housed within the CCU <NUM>. In some embodiments, the power system can be housed within the truck <NUM> and connected to one or more components of the climate control system <NUM> (e.g., a compressor, one or more fans and/or blowers, the climate controller <NUM>, one or more sensors, etc.). In some embodiments, the power system can be a generator set (not shown) attached to the truck <NUM> and connected to one or more components of the climate control system <NUM> (e.g., a compressor, one or more fans and/or blowers, the climate controller <NUM>, one or more sensors, etc.). The power system is a direct drive parallel power system as discussed in further detail below with respect to <FIG>, <FIG> and 3A and 3B.

<FIG> depicts a side view of a van <NUM> with a transport climate control system <NUM> for providing climate control within a climate controlled space <NUM>, according to one embodiment. The transport climate control system <NUM> includes a climate control unit (CCU) <NUM> that is mounted to a rooftop <NUM> of the van <NUM>. In an embodiment, the CCU <NUM> can be a transport refrigeration unit. The climate control system <NUM> also includes a programmable climate controller <NUM> and one or more sensors (not shown) that are configured to measure one or more parameters of the climate control system <NUM> (e.g., an ambient temperature outside of the van <NUM>, a space temperature within the climate controlled space <NUM>, an ambient humidity outside of the van <NUM>, a space humidity within the climate controlled space <NUM>, etc.) and communicate parameter data to the climate controller <NUM>.

The transport climate control system <NUM> can include, among other components, a transport climate control circuit (not shown) that connects, for example, a compressor, a condenser, an evaporator, and an expander (e.g., an expansion valve) to provide climate control within the climate controlled space <NUM>.

The climate controller <NUM> may comprise a single integrated control unit or may comprise a distributed network of climate controller elements (not shown). The number of distributed control elements in a given network can depend upon the particular application of the principles described herein. The climate controller <NUM> is configured to control operation of the climate control system <NUM> including the transport climate control circuit.

The climate control system <NUM> is powered by a power system that can distribute power to the climate control system <NUM> when a utility power source is unavailable. In some embodiments, the power system can be housed within the CCU <NUM>. In some embodiments, the power system can be housed within the van <NUM> and connected to one or more components of the climate control system <NUM> (e.g., a compressor, one or more fans and/or blowers, the climate controller <NUM>, one or more sensors, etc.). In some embodiments, the power system can be a generator set (not shown) attached to the van <NUM> and connected to one or more components of the climate control system <NUM> (e.g., a compressor, one or more fans and/or blowers, the climate controller <NUM>, one or more sensors, etc.). The power system is a direct drive parallel power system as discussed in further detail below with respect to <FIG>, <FIG> and 3A and 3B.

<FIG> is a perspective view of a passenger vehicle <NUM> including a transport climate control system <NUM>, according to one embodiment. In the embodiment illustrated in <FIG>, the passenger vehicle <NUM> is a mass-transit bus that can carry passenger(s) (not shown) to one or more destinations. In other embodiments, the passenger vehicle <NUM> can be a school bus, railway vehicle, subway car, or other commercial vehicle that carries passengers. Hereinafter, the term "vehicle" shall be used to represent all such passenger vehicles, and should not be construed to limit the scope of the application solely to mass-transit buses. The transport climate control system <NUM> can provide climate control within a climate controlled space which in this embodiment is a passenger compartment <NUM>.

The passenger vehicle <NUM> includes a frame <NUM>, a passenger compartment <NUM> supported by the frame <NUM>, wheels <NUM>, and a compartment <NUM>. The frame <NUM> includes doors <NUM> that are positioned on a side of the passenger vehicle <NUM>. A first door 158a is located adjacent to a forward end of the passenger vehicle <NUM>, and a second door 158b is positioned on the frame <NUM> toward a rearward end of the passenger vehicle <NUM>. Each door <NUM> is movable between an open position and a closed position to selectively allow access to the passenger compartment <NUM>.

The transport climate control system <NUM> includes a climate control unit (CCU) <NUM> that is mounted to a rooftop <NUM> of the passenger vehicle <NUM>. In an embodiment, the CCU <NUM> can be a HVAC unit. The climate control system <NUM> also includes a programmable climate controller <NUM> and one or more sensors (not shown) that are configured to measure one or more parameters of the transport climate control system <NUM> (e.g., an ambient temperature outside of the passenger vehicle <NUM>, a space temperature within the passenger compartment <NUM>, an ambient humidity outside of the passenger vehicle <NUM>, a space humidity within the passenger compartment <NUM>, etc.) and communicate parameter data to the climate controller <NUM>.

The transport climate control system <NUM> can include, among other components, a transport climate control circuit (not shown) that connects, for example, a compressor, a condenser, an evaporator, and an expander (e.g., an expansion valve) to provide climate control within the passenger compartment <NUM>.

The transport climate control system <NUM> can operate in multiple operation modes including, for example, a continuous cooling mode, a start/stop cooling mode, a heating mode, a defrost mode, a null mode, etc. When operating in a continuous cooling mode and/or a start-stop cooling mode, the transport climate control system <NUM> can operate in a pulldown setting and in a steady-state setting. The pulldown setting generally occurs when, for example, the passenger compartment <NUM> is being cooled from an ambient temperature down to a desired set-point temperature so that the transport climate control system <NUM> can bring the temperature down to the desired set-point temperature as quickly as possible. The steady-state setting generally occurs when, for example, the climate in the passenger compartment <NUM> has already reached or is close to approaching a desired set-point temperature and the transport climate control system <NUM> is working to maintain the desired set-point temperature.

The climate control system <NUM> is powered by a power system that can distribute power to the climate control system <NUM> when a utility power source is unavailable. In some embodiments, the power system can be housed within the CCU <NUM>. In some embodiments, the power system can be housed within the vehicle <NUM> and connected to one or more components of the climate control system <NUM> (e.g., a compressor, one or more fans and/or blowers, the climate controller <NUM>, one or more sensors, etc.). In some embodiments, the power system can be a generator set (not shown) attached to the passenger vehicle <NUM> and connected to one or more components of the climate control system <NUM> (e.g., a compressor, one or more fans and/or blowers, the climate controller <NUM>, one or more sensors, etc.). The power system is a direct drive parallel power system as discussed in further detail below with respect to <FIG>, <FIG> and 3A and 3B.

The compartment <NUM> is located adjacent the rear end of the passenger vehicle <NUM>, can include the power system. In some embodiments, the compartment <NUM> can be located at other locations on the vehicle <NUM> (e.g., adjacent the forward end, etc.).

<FIG> illustrates one embodiment of an intermodal container <NUM> with a transport climate control system <NUM> and a power system <NUM>. The intermodal container <NUM> can be used across different modes of transport including, for example, ship, rail, tractor-trailer, etc..

The transport climate control system <NUM> includes a climate control unit (CCU) <NUM> that provides environmental control (e.g. temperature, humidity, air quality, etc.) within a climate controlled space <NUM> of the intermodal container <NUM>. The climate control system <NUM> also includes a programmable climate controller <NUM> and one or more sensors (not shown) that are configured to measure one or more parameters of the climate control system <NUM> (e.g., an ambient temperature outside of the intermodal container <NUM>, a space temperature within the climate controlled space <NUM>, an ambient humidity outside of the intermodal container <NUM>, a space humidity within the climate controlled space <NUM>, etc.) and communicate parameter data to the climate controller <NUM>.

When operating in a continuous cooling mode and/or a start-stop cooling mode, the transport climate control system <NUM> can operate in a pulldown setting and in a steady-state setting. The pulldown setting generally occurs when, for example, the climate controlled space <NUM> is being cooled from an ambient temperature down to a desired set-point temperature so that the transport climate control system <NUM> can bring the temperature down to the desired set-point temperature as quickly as possible. The steady-state setting generally occurs when, for example, the climate in the climate controlled space <NUM> has already reached or is close to approaching a desired set-point temperature and the transport climate control system <NUM> is working to maintain the desired set-point temperature.

The CCU <NUM> is disposed on a front wall <NUM> of the intermodal container <NUM>. In other embodiments, it will be appreciated that the CCU <NUM> can be disposed, for example, on a rooftop or another wall of the intermodal container <NUM>. The CCU <NUM> includes a transport climate control circuit (not shown) that connects, for example, a compressor, a condenser, an evaporator and an expander (e.g., expansion valve) to provide conditioned air within the climate controlled space <NUM>.

The climate control system <NUM> is powered by the power system <NUM> that can distribute power to the climate control system <NUM> when a utility power source is unavailable. In this embodiment, the power system <NUM> is a generator set disposed on a bottom wall <NUM> of the intermodal container <NUM> and connected to one or more components of the climate control system <NUM> (e.g., a compressor, one or more fans and/or blowers, the climate controller <NUM>, one or more sensors, etc.).

In this embodiment, the power system <NUM> includes a housing <NUM> attached to a frame <NUM> by a mounting assembly <NUM>. The mounting assembly <NUM> can extend between the housing <NUM> and cross members <NUM> that are part of the frame <NUM>. The mounting assembly <NUM> can be made of a high-strength material (e.g., steel, etc.) to rigidly attach the power system <NUM> to the intermodal container <NUM>. The power system <NUM> includes a power system controller <NUM> that is configured to control operation of the power system <NUM>. The power system <NUM> is a direct drive parallel power system as discussed in further detail below with respect to <FIG>, <FIG> and 3A and 3B.

It will be appreciated that the transport climate control systems described above with respect to <FIG> can operate in multiple operation modes including, for example, a continuous cooling mode, a start/stop cooling mode (also referred to as a cycle-sentry cooling mode), a heating mode, a defrost mode, a null mode, etc..

Of particular note, in the continuous cooling mode, a transport climate control system controller is configured to instruct a compressor to continuously compress the working fluid until the temperature within the climate controlled space reaches a desired setpoint temperature. In the start-stop cooling mode, the transport climate control system controller is configured to instruct the compressor to operate in a periodic cycle in which during each cycle the compressor is configured to compress the working fluid for a first period of time and then the compressor is configured to stop compressing the working fluid for a second period of time. The compressor will continue to cycle between compressing the working fluid and not compressing the working fluid until the temperature within the climate controlled space reaches the desired setpoint temperature. In some embodiments, the compressor is configured to compress the working fluid and direct the compressed working fluid from the compressor to the condenser during the start portion and configured to not compress working fluid during the stop portion. In some embodiments, during the stop portion of the start-stop cooling mode fan(s) of the condenser and the evaporator are turned off and are not operating.

It will be appreciated that the amount of power demanded from the transport climate control system varies depending on whether the transport climate control system is operating in the start portion of the start-stop cooling mode or the stop portion of the start-stop cooling mode. Particularly, the amount of power demanded by the transport climate control system during the start portion can be at or near a wide-open throttle (e.g., the prime mover operating at peak torque) of a prime mover of a power system and can be below the wide-open throttle of the prime mover during the stop portion. Accordingly, the prime mover can operate with increased fuel efficiency during the start portion and can operate with decreased fuel efficiency during the stop portion.

<FIG> and <FIG> illustrate different embodiments of a direct drive parallel power system <NUM>, <NUM> that can be used to power a transport climate control system (e.g. the transport climate systems <NUM>, <NUM>, <NUM>, <NUM> and <NUM> shown in <FIG>). The direct drive parallel power system <NUM> includes a power train <NUM> that includes a prime mover <NUM>, a motor-generator <NUM>, and a drive shaft <NUM>. The direct drive parallel power system <NUM> also includes a battery source <NUM> that is electrically connected to the motor-generator <NUM>. The direct drive parallel power system <NUM> can also include an optional battery charger <NUM> that is configured to be electrically connected to the battery source <NUM>. Also, the direct drive parallel power system <NUM> includes a power system controller <NUM> configured to monitor and control operation of the direct drive parallel power system <NUM>.

The direct drive parallel power system <NUM> can be used (via the drive shaft <NUM> of the powertrain <NUM>) to supply mechanical power to one or more direct driven loads <NUM>. Mechanical power can be supplied to the one or more direct driven loads <NUM> via the drive shaft <NUM> of the powertrain <NUM>. The drive shaft <NUM> can receive mechanical power directly from the prime mover <NUM>, directly from the motor-generator <NUM>, or directly from both of the prime mover <NUM> and the motor-generator <NUM>. The direct drive parallel power system <NUM> can also be used (via the electrical machine <NUM> and the battery source <NUM>) to supply electrical power to one or more electrically driven loads <NUM>. In some embodiments, the one or more direct driven load <NUM> can include a direct drive compressor that is configured to compress a working fluid (e.g., refrigerant) passing through a climate control circuit (see, for example, <FIG>). In some embodiments, the one or more direct driven load <NUM> can include, for example, one or more belt driven fans, blowers, etc. In some embodiments, the one or more electrically driven loads <NUM> can include, for example, one or more condenser fans, one or more evaporator blowers, a transport climate control system controller, a telematics unit, one or more electric heater bars (that can be mounted in an evaporator compartment and activated with an evaporator fan to provide heat within the climate controlled space), etc..

The prime mover <NUM> is configured to generate mechanical power that can be used to supply power to the one or more direct driven loads <NUM> via the drive shaft <NUM>. In some embodiments, the prime mover <NUM> can be an internal combustion engine such as, for example, a diesel engine, gasoline engine, a compressed natural gas (CNG) engine, a liquid nitrogen gas (LNG) engine, etc. In some embodiments, the prime mover <NUM> can be a mechanical injection engine that uses a mechanical governor to control operation of the engine. In some embodiments, the prime mover <NUM> can be a mechanical injection engine that uses an electronic governor and an engine control unit (ECU) to control and monitor operation of the engine. In some embodiments, the prime mover <NUM> can be a common rail injection engine that uses an electronic injection and an engine control unit (ECU) to control and monitor operation of the engine.

In some embodiments, the prime mover <NUM> can be a small diesel engine that supplies less than <NUM> kilowatts of mechanical power. In some embodiments, the prime mover <NUM> can be a large diesel engine that supplies <NUM> kilowatts or more of mechanical power.

It will be appreciated that the prime mover <NUM> can be most efficient when operating close to wide-open throttle (e.g., peak torque) and then drops off slightly as the prime mover <NUM> reaches peak torque. Operating close to wide-open throttle can be at a percent torque between, for example, <NUM>-<NUM>% of peak torque. However, in many situations, the load(s) (including the one or more direct driven loads <NUM>, the one or more electrically driven loads <NUM>, etc.) demanding power from the direct drive parallel power system <NUM> are not demanding power at a level for the prime mover <NUM> to operate with a wide-open throttle and the load(s) may not be in communication with the direct drive parallel power system <NUM>.

By using a small diesel engine rather than a large diesel engine, the power system can operate more frequently closer to peak torque and the small diesel engine's optimal efficiency point. By increasing the amount of time that the prime mover <NUM> is operated at a wide-open throttle, the fuel efficiency of the power system can be achieved. Also, avoiding operation of the prime mover <NUM> during a low load demand can prevent rapid formation of exhaust deposits on, for example, injector tips, exhaust piping, an exhaust gas recirculation (EGR) cooler, an EGR valve, EGR piping, an exhaust manifold, a diesel oxidation catalyst (DOC), exhaust gas sensors, and other related components of the power system that can occur when the prime mover <NUM> is running and there is low load demand. These deposit formations can degrade performance and efficiency of the prime mover <NUM> and can increase maintenance intervals.

The motor-generator <NUM> includes a motor that is configured to receive electrical power from the battery source <NUM> and generate mechanical power that can be used to supply power to the one or more direct driven loads <NUM> via the drive shaft <NUM>. The motor-generator <NUM> also includes a generator that is configured to receive and convert mechanical power generated by the prime mover <NUM> via the drive shaft <NUM> into electrical power and supply the electrical power to charge the battery source <NUM>. In some embodiments, the motor-generator <NUM> is configured to convert mechanical power generated by the prime mover <NUM> into direct current (DC) power for charging the battery source <NUM>. In some embodiments, the motor-generator <NUM> can be a small motor-generator (e.g., an approximately <NUM>-<NUM> kilowatt motor-generator). In these embodiments, the motor-generator <NUM> can supplement the prime mover <NUM> during high power demand situations (e.g., load demand is greater than <NUM> kilowatts) and can operate without assistance of the prime mover <NUM> during low demand situations (e.g., load demand is less than <NUM> kilowatts). In some embodiments, the motor-generator <NUM> can be a large motor-generator (e.g., an approximately <NUM>-<NUM> kilowatt motor-generator). In these embodiments, the motor-generator <NUM> can supplement the prime mover <NUM> during high power demand situations (e.g., load demand is greater than <NUM> kilowatts) and can operate without assistance of the prime mover <NUM> during low demand situations (e.g., load demand is less than <NUM> kilowatts). In addition, when the power system <NUM>, <NUM> includes an optional battery charger <NUM> that is plugged into a utility power source, the motor-generator <NUM> has sufficient power generating capabilities to operate without assistance of the prime mover <NUM> during high power demand situations (e.g., load demand is greater than <NUM> kilowatts) such that the one or more direct driven loads <NUM> (via the motorgenerator <NUM>) and the one or more electrically driven loads <NUM> can be operating from the utility power source.

The battery source <NUM> is configured to supply electrical power to the one or more electrically driven loads <NUM>. In some embodiments, the battery source <NUM> is configured to supply DC power to the one or more electrically driven loads <NUM>. In some embodiments, for example, when the motor-generator <NUM> is a small motor-generator, the battery source <NUM> can be a small battery source (e.g., an approximately <NUM>-<NUM> Volt battery source). In some embodiments, for example, when the motor-generator <NUM> is a large motor-generator, the battery source <NUM> can be a large battery source (e.g., an approximately <NUM>-<NUM> Volt battery source).

The power system controller <NUM> is configured to monitor and control operation of the direct drive parallel power system <NUM>. In particular, the power system controller <NUM> is configured to control operation of the prime mover <NUM>, the motor-generator <NUM>, the battery source <NUM>, and the optional battery charger <NUM>. Also, the power system controller <NUM> can monitor how the prime mover <NUM> is operating and can switch between operation modes based on operation of the prime mover <NUM>.

The operation modes can include a prime mover operation mode in which the prime mover <NUM> is activated and configured to generate mechanical power and the motor of the motorgenerator <NUM> is deactivated. In the prime mover operation mode, the generated mechanical power from the prime mover <NUM> can then be transferred to the one or more direct driven loads <NUM> via the drive shaft <NUM>. Also, a portion of the generated mechanical power from the prime mover <NUM> can be transferred to the generator of the motor-generator <NUM>, whereby the mechanical power is converted into electrical power and can be used for charging the battery source <NUM>. The operation modes includes a parallel operation mode in which both the prime mover <NUM> and the motor of the motor-generator <NUM> is activated so that both the prime mover <NUM> and the motor-generator <NUM> are configured to generate mechanical power. In the parallel operation mode, both the generated mechanical power from the prime mover <NUM> and the motorgenerator <NUM> can then be transferred in parallel to the one or more direct driven loads <NUM> via the drive shaft <NUM>.

<FIG> illustrates a direct drive parallel power system <NUM> includes a powertrain <NUM> that is similar to the powertrain <NUM> but also includes a clutch <NUM> disposed between the prime mover <NUM> and the motor-generator <NUM> along a drive shaft <NUM>. The clutch <NUM> is configured to engage and disengage the prime mover <NUM> from the drive shaft <NUM> of the powertrain <NUM>. The power system controller <NUM> is configured to control operation of the clutch <NUM>.

By including the clutch <NUM>, the power system controller <NUM> can include a motorgenerator operation mode in which the motor of the motor-generator <NUM> is activated and configured to generate mechanical power and the prime mover <NUM> is deactivated and disengaged from the drive shaft <NUM>. In the motor-generator operation mode, the generated mechanical power from the motor-generator <NUM> can then be transferred to the one or more direct driven loads <NUM> via the drive shaft <NUM>. As the power system <NUM> shown in <FIG> does not include a clutch it cannot operate in the motor-generator operation mode even if the prime mover <NUM> is deactivated because the prime mover <NUM> remains engaged to the rotating drive shaft <NUM> and the motor-generator <NUM> would be attempting to turn over the prime mover <NUM>. An advantage of the motor-generator operation mode is that fuel efficiency of the prime mover <NUM> can be improved by deactivating the prime mover <NUM> when load demands from the one or more direct driven loads <NUM> and the one or more electrically driven loads <NUM> are relatively low. When the prime mover <NUM> is active, it can provide power for the direct driven loads <NUM> and/or the electrically driven loads <NUM> via the motor-generator <NUM> as well as for charging the battery source <NUM> in order to allow itself to operate at a higher torque level and better efficiency point that is near peak torque. When the battery source <NUM> is fully charged, the prime mover <NUM> can deactivate and the one or more electrically driven loads <NUM> and/or the one or more direct driven loads <NUM> (via the motor-generator <NUM>) can be operated from battery source <NUM> only for a period of time until the battery source <NUM> needs to be recharged again.

Also, in some embodiments, the direct drive parallel power system <NUM> can be used in geographical areas where, for example, a diesel engine is only allowed to run for a specified period of time or not allowed to run at all, there are low noise regulations, etc. In these embodiments, the direct drive parallel power system <NUM> can operate in the motor-generator operation mode while still providing sufficient power to operate the transport climate control system.

An advantage of the direct drive parallel power system <NUM> is that the prime mover <NUM> is not required to operate when load(s) (including the one or more direct driven loads <NUM>, the one or more electrically driven loads <NUM>, etc.) demanding power from the direct drive parallel power system <NUM> is low (e.g., less than <NUM>% prime mover load) or not demanding power at all. That is, the power system controller <NUM> can instruct the motor-generator <NUM> to supply power to the one or more direct driven loads <NUM> and/or instruct the battery source <NUM> to supply power to the one or more electrically driven loads <NUM> while instructing the prime mover <NUM> to shut off when the power demanded by the load(s) is less than a certain threshold (e.g., less than <NUM>% prime mover load). Accordingly, the prime mover <NUM> can be deactivated during periods of time where power demand is low to avoid low fuel efficiency conditions while still allowing one or more direct driven loads <NUM> (e.g., a direct drive compressor) to receive power (i.e., from the motorgenerator <NUM>).

In some embodiments, the direct drive parallel power systems <NUM>, <NUM> can include an optional battery charger <NUM>. The optional battery charger <NUM> can plug into a utility power source (not shown) when available to charge and provide power to the battery source <NUM>. This would allow the battery source <NUM> to power a motor of the motor-generator <NUM> (and thereby the one or more direct driven loads <NUM>) as well as to power the electrically driven loads <NUM>. Accordingly, the battery charger <NUM> could be used to provide utility power to the battery source <NUM> while operating in the parallel operation mode and/or a motor-generator operation mode. It will be appreciated that the optional battery charger <NUM> can be a modular addition to the direct drive parallel power systems <NUM>, <NUM> by a preferred service technician after manufacturing.

<FIG> illustrates a flowchart of a method <NUM> for operating the direct drive parallel power system <NUM>, <NUM>, according to one embodiment. The method <NUM> begins at <NUM>, whereby the power system controller <NUM> is configured to monitor a prime mover parameter indicating how the prime mover <NUM> is operating.

In some embodiments, (e.g., when the prime mover <NUM> is a mechanical injection diesel engine with a mechanical governor, etc.) the prime mover parameter can be a speed (e.g., revolutions per minute (RPM)) of the prime mover <NUM>. In these embodiments, the power systems <NUM>, <NUM> can include a speed sensor configured to monitor the speed of the prime mover <NUM> and communicate monitored speed data to the power system controller <NUM>. It will be appreciated that the prime mover speed can decrease when the prime mover <NUM> is at or near peak torque (e.g., at or near full speed) such as during high power demand situations (e.g., load demand is greater than <NUM> kilowatts) and that the prime mover speed can increase when the prime is operating below peak torque (e.g., below full speed) such as during low power demand situations (e.g., load demand is less than <NUM> kilowatts).

In some embodiments, (e.g., when the prime mover <NUM> is a mechanical injection diesel engine with an electric governor and an ECU, when the prime mover <NUM> is a common rail diesel engine with an electronic injection and an ECU, etc.) the prime mover parameter can be a prime mover percent load of the prime mover <NUM>. The prime mover percent load (PM%LOD) can indicate, for the current speed of the prime mover <NUM>, the amount of air/fuel delivery going through the prime mover <NUM> relative to the amount of air/fuel delivery going to the prime mover <NUM> at a wide-open throttle (e.g., the prime mover operating at peak torque). That is, the prime mover percent load can indicate a percentage of peak available torque of the prime mover <NUM>. In these embodiments, the power system controller <NUM> can communicate directly with the ECU of the prime mover <NUM> to obtain prime mover percent load data.

The method <NUM> then proceeds to <NUM>.

At <NUM>, the power system controller <NUM> compares the monitored prime mover parameter data with a prime mover threshold. The prime mover threshold can be set to a value that indicates whether the prime mover <NUM> is operating at or near a wide-open throttle (e.g., the prime mover operating at peak torque). It will be appreciated that the prime mover threshold can be a predefined value determined based on, for example, simulation data, field testing, etc. for the specific type of prime mover being used. In one example, the prime mover threshold can be a predefined percent torque value set somewhere between, for example, <NUM>-<NUM>% of peak torque.

In another example, when the prime mover parameter is the speed of the prime mover <NUM>, the power system controller <NUM> can determine whether the monitored prime mover data (e.g., prime mover speed) is greater than a prime mover threshold (e.g., a prime mover speed threshold). It will be appreciated that the prime mover speed threshold can be a predefined value determined based on, for example, simulation data, field testing, etc. for the specific type of prime mover being used. In some embodiments, such as when the prime mover <NUM> is a mechanically driven diesel engine (or in some cases an electrically driven diesel engine), the speed of the prime mover <NUM> when operating at a full-load condition (e.g., at or near peak torque) has been found to drop about <NUM>-<NUM>% below the speed of the prime mover <NUM> when operating under a no-load condition. For example, if the prime mover <NUM> is operating at a no-load condition speed of <NUM> RPM, the prime mover speed can drop to about <NUM> RPM when operating at a full-load condition. Accordingly, in some embodiments, the prime mover threshold can be set to a speed that would indicate that the prime mover <NUM> is no longer operating at a full-load condition and may be approaching a no-load condition. If the speed of the prime mover <NUM> is <NUM> RPM at a no-load condition, the prime mover threshold can be set to, for example, around <NUM> RPM.

When the power system controller <NUM> determines that monitored prime mover parameter data (e.g., prime mover speed) is greater than the prime mover threshold (e.g., prime mover speed threshold) (thereby indicating that the prime mover <NUM> is operating or approaching a no-load condition), the method <NUM> proceeds to <NUM>. When the power system controller <NUM> determines that monitored prime mover parameter data (e.g., prime mover speed) is not greater than the prime mover threshold (e.g., prime mover speed threshold) (thereby indicating that the prime mover <NUM> is operating at or near a full-load condition (e.g., at or near peak torque)), the method <NUM> proceeds to <NUM>. It will be appreciated, that when the power system includes the clutch <NUM> (e.g., the power system <NUM>), the method <NUM> proceeds to <NUM> instead of <NUM> when the power system controller <NUM> determines that monitored prime mover parameter data is not greater than the prime mover threshold.

In yet another example, when the prime mover parameter is a prime mover percent load of the prime mover <NUM>, the power system controller <NUM> can determine whether the monitored prime mover data (e.g., prime mover percent load) is less than a prime mover threshold (e.g., a prime mover percent load threshold). It will be appreciated that the prime mover percent load threshold can be a predefined value determined based on, for example, simulation data, field testing, etc. for the specific type of prime mover being used. In some embodiments, the prime mover percent load threshold can be set to a predefined value between, for example, <NUM>-<NUM>%. Thus, when prime mover percent load drops below the prime mover percent load threshold, the power system controller can determine that the prime mover <NUM> is not operating at a full-load condition and is approaching or near a no-load condition.

When the power system controller <NUM> determines that monitored prime mover parameter data (e.g., prime mover percent load) is less than the prime mover threshold (e.g., prime mover percent load threshold), the method <NUM> proceeds to <NUM>. When the power system controller <NUM> determines that monitored prime mover parameter data (e.g., prime mover percent load) is not less than the prime mover threshold (e.g., prime mover percent load threshold), the method <NUM> proceeds to <NUM>. It will be appreciated, that when the power system includes the clutch <NUM> (e.g., the power system <NUM>), the method <NUM> proceeds to <NUM> instead of <NUM> when the power system controller <NUM> determines that monitored prime mover parameter data is not less than the prime mover threshold.

At <NUM>, the power system controller <NUM> determines that the load demand on the prime mover <NUM> is not sufficient to allow the prime mover <NUM> to be capable of operating at or near a wide-open throttle (i.e., the prime mover <NUM> is not operating efficiently). Accordingly, the power system controller <NUM> operates the direct drive parallel power system <NUM>, <NUM> in a parallel operation mode such that both the prime mover <NUM> and the motor of the motorgenerator <NUM> can concurrently provide mechanical power to the one or more direct driven loads <NUM> via the driveshaft <NUM>, <NUM>. It will be appreciated that the battery source <NUM> is configured to supply electrical power to the motor of the motor-generator <NUM> to allow the motor of the motor-generator <NUM> to provide mechanical power to the one or more direct driven loads <NUM>. The battery source <NUM> can also provide electrical power to the one or more electrically driven loads <NUM>. It will be appreciated that in some embodiments the method <NUM> at <NUM> can allow the power system controller <NUM> to instruct the power system controller <NUM> to operate in the parallel operation mode temporarily in high power demand situations such as when the transport climate control system is operating in a fast pulldown setting to cool a climate controlled space from, for example, an ambient temperature to a desired setpoint temperature within the climate controlled space. The method <NUM> then proceeds back to <NUM>.

At <NUM>, the power system controller <NUM> determines that the load demand on the prime mover <NUM> is sufficient to allow the prime mover <NUM> to be capable of operating at or near a wide-open throttle (i.e., the prime mover <NUM> is operating efficiently). Accordingly, the power system controller <NUM> operates the direct drive parallel power system <NUM>, <NUM> in a prime mover operation mode such that the prime mover <NUM> without assistance from the motor-generator <NUM> can provide mechanical power to the one or more direct driven loads <NUM> via the drive shaft <NUM>, <NUM>. In some embodiments, the power system controller <NUM> can determine whether the battery source <NUM> is at or near a fully charged state and can instruct the prime mover <NUM> to charge the battery source <NUM> when the battery source <NUM> is not at or near a fully charged state (e.g., the charge level of the battery source <NUM> is at or below <NUM>%). In some embodiments, the power system controller <NUM> can instruct the prime mover <NUM> to continue to charge the battery source <NUM> until the charge level of the battery source <NUM> is, for example, at or above <NUM>%. It will be appreciated that the power system controller <NUM> can determine when to initiate charging of the battery source <NUM> and when to stop charging the battery source <NUM> based on, for example, a battery source manufacturer recommendation. The battery source <NUM> can also provide electrical power to the one or more electrically driven loads <NUM>. The method <NUM> then proceeds back to <NUM>.

At <NUM> (e.g., when the power system includes the clutch <NUM>), the power system controller <NUM> determines whether the battery source <NUM> is sufficiently charged (e.g., the charge level of the battery source <NUM> is above a charge level threshold). In some embodiments, the charge level threshold can be, for example, <NUM>%. It will be appreciated that the charge level threshold can be a predefined value determined based on, for example, simulation data, field testing, battery source manufacturer recommendation(s), etc. When the power system controller <NUM> determines that the battery source <NUM> is not sufficiently charged, the method <NUM> proceeds to <NUM>. When the power system controller <NUM> determines that the battery source <NUM> is sufficiently charged, the method <NUM> proceeds to <NUM>.

At <NUM>, the power system controller <NUM> operates the direct drive parallel power system <NUM> in a motor-generator operation mode. Accordingly, the power system controller <NUM> operates the direct drive parallel power system <NUM> such that the motor of the motor-generator <NUM>, without assistance from the prime mover <NUM>, can provide power to the one or more direct driven loads <NUM> via the drivetrain <NUM>. It will be appreciated that the battery source <NUM> is configured to supply electrical power to the motor of the motor-generator <NUM> to allow the motor of the motor-generator <NUM> to provide mechanical power to the one or more direct driven loads <NUM> via the driveshaft <NUM>. The battery source <NUM> can also provide electrical power to the one or more electrically driven loads <NUM>. The method <NUM> then proceeds back to <NUM>.

An advantage of the method <NUM> is that based on monitored prime mover parameter data, a) the prime mover <NUM> in combination with the motor-generator <NUM> can concurrently supply mechanical power to the one or more direct driven loads <NUM>, b) the prime mover <NUM> can supply mechanical power to the one or more direct driven loads <NUM> without assistance of the motorgenerator <NUM>, and c) (optionally when then clutch <NUM> is available the motor-generator <NUM>) can supply mechanical power to the one or more direct driven loads <NUM> without assistance of the prime mover <NUM>. Accordingly, the power system <NUM>, <NUM> can provide power to the one or more direct driven loads <NUM> and the one or more electrically driven loads <NUM> when demanded while preventing operation of the prime mover <NUM> in low power demand situations when the prime mover <NUM> may not be able to operate efficiently.

<FIG> is a schematic diagram of a climate control circuit <NUM>, according to one embodiment. The climate control circuit <NUM> generally includes a compressor <NUM>, a condenser <NUM>, an expander <NUM> (e.g., an expansion valve or the like), and an evaporator <NUM>. The climate control circuit <NUM> is exemplary and can be modified to include additional components. For example, in some embodiments the climate control circuit <NUM> can include an economizer heat exchanger, one or more flow control devices (e.g., valves or the like), a receiver tank, a dryer, a suction-liquid heat exchanger, or the like.

The climate control circuit <NUM> can generally be applied in a variety of systems used to control an environmental condition (e.g., temperature, humidity, air quality, or the like) in a space (generally referred to as a climate controlled space). Examples of systems include, but are not limited to the transport climate control systems shown and described above in accordance with <FIG>.

The components of the climate control circuit <NUM> are fluidly connected. The climate control circuit <NUM> can be specifically configured to be a cooling system (e.g., an air conditioning system) capable of operating in a cooling mode. Alternatively, the climate control circuit <NUM> can be specifically configured to be a heat pump system which can operate in both a cooling mode and a heating/defrost mode.

The climate control circuit <NUM> operates according to generally known principles. The climate control circuit <NUM> can be configured to heat or cool heat transfer fluid or medium (e.g., a gas such as, but not limited to, air or the like), in which case the climate control circuit <NUM> may be generally representative of an air conditioner or heat pump.

The compressor <NUM> can be, for example, a scroll compressor, a reciprocal compressor, or the like. In some embodiments, the compressor <NUM> can be a mechanically driven compressor. In other embodiments, the compressor <NUM> can be an electrically driven compressor. The compressor <NUM> is configured to compress a working fluid (e.g., refrigerant) and direct the working fluid through the climate control circuit <NUM> in order to provide temperature control within a climate controlled space (e.g., the climate controlled spaces shown in <FIG>). In particular, the compressor <NUM> is configured to direct the compressed working fluid that is a gas to the condenser <NUM>.

The condenser <NUM> can include a condenser coil (not shown) and one or more condenser fans. The condenser <NUM> is configured to allow the working fluid, received from the compressor <NUM>, to transform from a gas to a liquid by releasing heat absorbed by the working fluid into the ambient environment outside of the climate controlled space. That is, the condenser <NUM> is configured to cool and condense the working fluid. The condenser <NUM> is configured to direct the liquid working fluid to the expander <NUM>.

The expander <NUM> is configured to receive the working fluid in the form of a liquid from the condenser <NUM> and is configured to restrict the flow of the working fluid in the form of a gas to the evaporator <NUM>. In some embodiments, the expander <NUM> can be an expansion valve. The gaseous working fluid is directed by the expander <NUM> to the evaporator <NUM>.

The evaporator <NUM> can include an evaporator coil (not shown) and one or more evaporator fans. The evaporator <NUM> is configured to allow the working fluid, received from the expander <NUM>, to evaporate from a liquid to a gas by absorbing heat from the climate controlled space and thereby provide cooling to the climate controlled space.

A controller (e.g., the climate controllers shown in <FIG>) is configured to control the climate control circuit <NUM> to operate in a plurality of different operation modes including, for example, a continuous cooling mode, a start-stop cooling mode, a heating mode, etc..

Of particular note, in the continuous cooling mode, the controller is configured to instruct the compressor <NUM> to continuously compress the working fluid until the temperature within the climate controlled space reaches a desired setpoint temperature. In the start-stop cooling mode, the controller is configured to instruct the compressor <NUM> to operate in a periodic cycle in which during each cycle the compressor <NUM> is configured to compress the working fluid for a first period of time (e.g., during a start portion of the start-stop cooling mode) and then the compressor <NUM> is configured to stop compressing the working fluid for a second period of time (e.g., during a stop portion of the start-stop cooling mode). The compressor <NUM> will continue to cycle between compressing the working fluid and not compressing the working fluid until the temperature within the climate controlled space reaches the desired setpoint temperature. In some embodiments, the compressor <NUM> is configured to compress the working fluid and direct the compressed working fluid from the compressor <NUM> to the condenser <NUM> during the start portion and configured to not compress working fluid during the stop portion. In some embodiments, during the stop portion of the start-stop cooling mode fan(s) of the condenser <NUM> and the evaporator <NUM> are turned off and are not operating.

When operating in the continuous cooling mode and/or a start portion of the start-stop cooling mode, the compressor <NUM> compresses a working fluid (e.g., refrigerant or the like) from a relatively lower pressure gas to a relatively higher-pressure gas. The relatively higher-pressure and higher temperature gas is discharged from the compressor <NUM> and flows through the condenser <NUM>. In accordance with generally known principles, the working fluid flows through the condenser <NUM> and rejects heat to a heat transfer fluid or medium (e.g., air, etc.), thereby cooling the working fluid. The cooled working fluid, which is now in a liquid form, flows to the expander <NUM>. The expander <NUM> reduces the pressure of the working fluid. As a result, a portion of the working fluid is converted to a gaseous form. The working fluid, which is now in a mixed liquid and gaseous form flows to the evaporator <NUM>. The working fluid flows through the evaporator <NUM> and absorbs heat from a heat transfer medium (e.g., air, etc.), heating the working fluid, and converting it to a gaseous form. The gaseous working fluid then returns to the compressor <NUM>.

The terminology used in this description is intended to describe particular embodiments and is not intended to be limiting. The terms "a," "an," and "the" include the plural forms as well, unless clearly indicated otherwise. The terms "comprises" and/or "comprising," when used in this description, specify the presence of the stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and/or components.

Claim 1:
A direct drive parallel power system (<NUM>, <NUM>) for powering a transport climate control system, the direct drive parallel power system comprising:
a powertrain (<NUM>) that includes a prime mover (<NUM>), a motor-generator (<NUM>), and a drive shaft (<NUM>), wherein the prime mover is configured to generate mechanical power for powering a direct driven load (<NUM>) of the transport climate control system via the drive shaft, wherein the motor-generator includes a motor and a generator, and wherein the motor is configured to generate mechanical power for powering the direct driven load via the drive shaft;
a battery source (<NUM>) electrically connected to the generator of the motor-generator, wherein the battery source is configured to supply electrical power to the motor of the motorgenerator and configured to supply electrical power to an electrically driven load of the transport climate control system; and
a power system controller (<NUM>) configured to monitor and control operation of the prime mover, the motor-generator, and the battery source;
characterized in that the power system controller is configured to operate the direct drive parallel power system in a parallel operation mode in which both the prime mover and the motorgenerator are instructed to concurrently supply mechanical power via the drive shaft to the direct driven load.