MULTI CHARGING SYSTEM ARCHITECTURE

A transport refrigeration system including: a transportation refrigeration unit configured to provide conditioned air to a refrigerated cargo space; an energy management system including: an energy storage device configured to store DC electrical energy to power the transportation refrigeration unit; an input DC-to-DC inverter electrically connected to the energy storage device; and an input AC-to-DC inverter electrically connected to the energy storage device.

BACKGROUND

The embodiments herein generally relate to transport refrigeration systems and more specifically, the energy management of such transport refrigeration systems.

Typically, cold chain distribution systems are used to transport and distribute cargo, or more specifically perishable goods and environmentally sensitive goods (herein referred to as perishable goods) that may be susceptible to temperature, humidity, and other environmental factors. Perishable goods may include but are not limited to fruits, vegetables, grains, beans, nuts, eggs, dairy, seed, flowers, meat, poultry, fish, ice, and pharmaceuticals. Advantageously, cold chain distribution systems allow perishable goods to be effectively transported and distributed without damage or other undesirable effects.

Refrigerated vehicles and trailers are commonly used to transport perishable goods in a cold chain distribution system. A transport refrigeration system is mounted to the vehicles or to the trailer in operative association with a cargo space defined within the vehicles or trailer for maintaining a controlled temperature environment within the cargo space.

Conventionally, transport refrigeration systems used in connection with refrigerated vehicles and refrigerated trailers include a transportation refrigeration unit having a refrigerant compressor, a condenser with one or more associated condenser fans, an expansion device, and an evaporator with one or more associated evaporator fans, which are connected via appropriate refrigerant lines in a closed refrigerant flow circuit. Air or an air/gas mixture is drawn from the interior volume of the cargo space by means of the evaporator fan(s) associated with the evaporator, passed through the airside of the evaporator in heat exchange relationship with refrigerant whereby the refrigerant absorbs heat from the air, thereby cooling the air. The cooled air is then supplied back to the cargo space.

On commercially available transport refrigeration systems used in connection with refrigerated vehicles and refrigerated trailers, the compressor, and typically other components of the transportation refrigeration unit, must be powered during transit by a prime mover. In mechanically driven transport refrigeration systems the compressor is driven by the prime mover, either through a direct mechanical coupling or a belt drive, and other components, such as the condenser and evaporator fans are belt driven.

Transport refrigeration systems may also be electrically driven. In an electrically driven transport refrigeration system, a prime mover carried on and considered part of the transport refrigeration system, drives an alternating (AC) synchronous generator that generates AC power. The generated AC power is used to power an electric motor for driving the refrigerant compressor of the transportation refrigeration unit and also powering electric AC fan motors for driving the condenser and evaporator motors and electric heaters associated with the evaporator. A more efficient method to power the electric motor is desired to reduce fuel usage.

BRIEF DESCRIPTION

According to one embodiment, a transport refrigeration system is provided. The transport refrigeration system including: a transportation refrigeration unit configured to provide conditioned air to a refrigerated cargo space; an energy management system including: an energy storage device configured to store DC electrical energy to power the transportation refrigeration unit; an input DC-to-DC inverter electrically connected to the energy storage device; and an input AC-to-DC inverter electrically connected to the energy storage device.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy management system further includes: an output DC-to-AC inverter electrically connecting the energy storage device to the transportation refrigeration unit, the output DC-to-AC inverter being configured to convert the DC electrical energy from the energy storage device to AC electrical energy to power the transportation refrigeration unit.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the input AC-to-DC inverter is configured to electrically connect to at least one of a high voltage 400V/3/50HZ grid, a low voltage 230V/3/50HZ grid, an AC electrical energy inverter eco-drive, or a vehicle alternator.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station, and wherein the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station, and wherein the input AC-to-DC inverter is configured to electrically connect to at least one of a high voltage 400V/3/50HZ grid, a low voltage 230V/3/50HZ grid, an AC electrical energy inverter eco-drive, or a vehicle alternator.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device, and wherein the input AC-to-DC inverter is configured to electrically connect to at least one of a high voltage 400V/3/50HZ grid, a low voltage 230V/3/50HZ grid, an AC electrical energy inverter eco-drive, or a vehicle alternator.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station, wherein the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device, and wherein the input AC-to-DC inverter is configured to electrically connect to at least one of a high voltage 400V/3/50HZ grid, a low voltage 230V/3/50HZ grid, an AC electrical energy inverter eco-drive, or a vehicle alternator.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station, wherein the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device, and wherein the input AC-to-DC inverter is configured to electrically connect to a high voltage 400V/3/50HZ grid.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station, wherein the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device, and wherein the input AC-to-DC inverter is configured to electrically connect to a low voltage 230V/3/50HZ grid.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station, wherein the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device, and wherein the input AC-to-DC inverter is configured to electrically connect to an AC electrical energy inverter eco-drive.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station, wherein the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device, and wherein the input AC-to-DC inverter is configured to electrically connect to a vehicle alternator.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station, wherein the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device, and wherein the input AC-to-DC inverter is configured to electrically connect to a high voltage 400V/3/50HZ grid and at least one of a low voltage 230V/3/50HZ grid, an AC electrical energy inverter eco-drive, or a vehicle alternator.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station, wherein the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device, and wherein the input AC-to-DC inverter is configured to electrically connect to a high voltage 400V/3/50HZ grid, a low voltage 230V/3/50HZ grid, and at least one of an AC electrical energy inverter eco-drive, or a vehicle alternator.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station, wherein the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device, and wherein the input AC-to-DC inverter is configured to electrically connect to a high voltage 400V/3/50HZ grid, a low voltage 230V/3/50HZ grid, and an AC electrical energy inverter eco-drive.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station, wherein the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device, and wherein the input AC-to-DC inverter is configured to electrically connect to a high voltage 400V/3/50HZ grid, a low voltage 230V/3/50HZ grid, and a vehicle alternator.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that the energy storage device is configured to electrically connect to a DC fast charging station, wherein the input DC-to-DC inverter is configured to electrically connect to a truck energy storage device, and wherein the input AC-to-DC inverter is configured to electrically connect to a high voltage 400V/3/50HZ grid, a low voltage 230V/3/50HZ grid, an AC electrical energy inverter eco-drive, and a vehicle alternator.

According to another method of operating a transport refrigeration system is provided. The method including: providing conditioned air to a refrigerated cargo space using a transportation refrigeration unit; storing DC electrical energy to power the transportation refrigeration unit using an energy storage device; and charging the energy storage device using at least one of an input DC-to-DC inverter electrically connected to the energy storage device, an input AC-to-DC inverter electrically connected to the energy storage device, or a DC fast charging station electrically connected to the energy storage device.

In addition to one or more of the features described above, or as an alternative, further embodiments of the transport refrigeration system may include that at least one of receiving electrical energy at the input DC-to-DC inverter from a truck energy storage device; or receiving electrical energy at the input AC-to-DC inverter from at least one of a high voltage 400V/3/50HZ grid, a low voltage 230V/3/50HZ grid, an AC electrical energy inverter eco-drive, or a vehicle alternator.

Technical effects of embodiments of the present disclosure include charging an energy storage device of an transportation refrigeration unit using at least one of a DC Fast charging station, a DC electrical energy362from the truck energy storage device326, a high voltage 400v/3/50HZ grid364, a low voltage 230V/3/50HZ grid366, an AC electrical energy inverter ECO-drive368, and an AC electrical energy369from the vehicle alternator322of the vehicle102.

DETAILED DESCRIPTION

Referring toFIGS. 1 and 2, various embodiments of the present disclosure are illustrated.FIG. 1shows a schematic illustration of a transport refrigeration system200, according to an embodiment of the present disclosure.FIG. 2shows an enlarged schematic illustration of the transport refrigeration system200ofFIG. 1, according to an embodiment of the present disclosure.

The transport refrigeration system200is being illustrated as a truck or trailer system100, as seen inFIG. 1. The trailer system100includes a vehicle102integrally connected to a transport container106. The vehicle102includes an operator's compartment or cab104and a propulsion motor, which acts as the drive system of the truck or trailer system100. The propulsion motor is configured to power the vehicle102. The propulsion motor may be a combustion engine320that runs on a fuel, such as, compressed natural gas, liquefied natural gas, gasoline, diesel, or a combination thereof. The propulsion motor may be an electric motor324that runs on electricity from a truck energy storage device326(e.g., battery pack). The propulsion motor may also be a combination of the combustion engine320and the electric motor324, such as, for example, a hybrid motor. It is understood that while both a combustion engine320and the electric motor324are illustrated inFIG. 1, the embodiments disclosed herein apply to a propulsion motor composed of the combustion engine320and/or the electric motor324. The combustion engine320may be operably connected to a vehicle alternator322to generate electricity. The electricity generated by the vehicle alternator322may be utilized to charge the truck energy storage device326.

The transport container106is coupled to the vehicle102. The transport container106may be removably coupled to the vehicle102. The transport container106is a refrigerated trailer and includes a top wall108, a directly opposed bottom wall110, opposed side walls112, and a front wall114, with the front wall114being closest to the vehicle102. The transport container106further includes a door or doors117at a rear wall116, opposite the front wall114. The walls of the transport container106define a refrigerated cargo space119. The refrigerated cargo space119may be subdivided into multiple different compartments that each have a different controlled environment (e.g., different temperature). It is appreciated by those of skill in the art that embodiments described herein may be applied to a tractor-trailer refrigerated system or non-trailer refrigeration such as, for example a rigid truck, a truck having refrigerated compartment.

Typically, transport refrigeration systems200are used to transport and distribute perishable goods and environmentally sensitive goods (herein referred to as perishable goods118). The perishable goods118may include but are not limited to fruits, vegetables, grains, beans, nuts, eggs, dairy, seed, flowers, meat, poultry, fish, ice, blood, pharmaceuticals, or any other suitable cargo requiring temperature controlled transport. The transport refrigeration system200includes a transportation refrigeration unit22, a refrigerant compression device32, an electric motor26for driving the refrigerant compression device32, and a controller30. The transportation refrigeration unit22is in operative association with the refrigerated cargo space112and is configured to provide conditioned air to the transport container106. The transportation refrigeration unit22functions, under the control of the controller30, to establish and regulate a desired environmental parameters, such as, for example temperature, pressure, humidity, carbon dioxide, ethylene, ozone, light exposure, vibration exposure, and other conditions in the refrigerated cargo space119, as known to one of ordinary skill in the art. In an embodiment, the transportation refrigeration unit22is capable of providing a desired temperature and humidity range.

The transportation refrigeration unit22includes a refrigerant compression device32, a refrigerant heat rejection heat exchanger34(e.g., condenser), an expansion device36, and a refrigerant heat absorption heat exchanger38(e.g., evaporator) connected in refrigerant flow communication in a closed loop refrigerant circuit and arranged in a conventional refrigeration cycle. The transportation refrigeration unit22also includes one or more fans40associated with the refrigerant heat rejection heat exchanger34and driven by fan motor(s)42and one or more fans44associated with the refrigerant heat absorption heat exchanger38and driven by fan motor(s)46. The transportation refrigeration unit22may also include a heater48associated with the refrigerant heat absorption heat exchanger38. In an embodiment, the heater48may be an electric resistance heater. It is to be understood that other components (not shown) may be incorporated into the refrigerant circuit as desired, including for example, but not limited to, a suction modulation valve, a receiver, a filter/dryer, an economizer circuit. It is also to be understood that additional refrigeration circuits may be run in parallel and powered by an energy storage device350as desired.

The refrigerant heat rejection heat exchanger34may, for example, comprise one or more refrigerant conveying coiled tubes or one or more tube banks formed of a plurality of refrigerant conveying tubes across flow path to the heat outlet142. The fan(s)40are operative to pass air, typically ambient air, across the tubes of the refrigerant heat rejection heat exchanger34to cool refrigerant vapor passing through the tubes. The refrigerant heat rejection heat exchanger34may operate either as a refrigerant condenser, such as if the transportation refrigeration unit22is operating in a subcritical refrigerant cycle or as a refrigerant gas cooler, such as if the transportation refrigeration unit22is operating in a transcritical cycle.

The refrigerant heat absorption heat exchanger38may, for example, also comprise one or more refrigerant conveying coiled tubes or one or more tube banks formed of a plurality of refrigerant conveying tubes extending across flow path from a return air intake136. The fan(s)44are operative to pass air drawn from the refrigerated cargo space119across the tubes of the refrigerant heat absorption heat exchanger38to heat and evaporate refrigerant liquid passing through the tubes and cool the air. The air cooled in traversing the refrigerant heat rejection heat exchanger38is supplied back to the refrigerated cargo space119through a refrigeration unit outlet140. It is to be understood that the term “air” when used herein with reference to the atmosphere within the cargo box includes mixtures of air with other gases, such as for example, but not limited to, nitrogen or carbon dioxide, sometimes introduced into a refrigerated cargo box for transport of perishable produce.

Airflow is circulated into and through the refrigerated cargo space119of the transport container106by means of the transportation refrigeration unit22. A return airflow134flows into the transportation refrigeration unit22from the refrigerated cargo space119through the return air intake136, and across the refrigerant heat absorption heat exchanger38via the fan44, thus conditioning the return airflow134to a selected or predetermined temperature. The conditioned return airflow134, now referred to as supply airflow138, is supplied into the refrigerated cargo space119of the transport container106through the refrigeration unit outlet140. Heat135is removed from the refrigerant heat rejection heat exchanger34through the heat outlet142. The transportation refrigeration unit22may contain an external air inlet144, as shown inFIG. 2, to aid in the removal of heat135from the refrigerant heat rejection heat exchanger34by pulling in external air137. The supply airflow138may cool the perishable goods118in the refrigerated cargo space119of the transport container106. It is to be appreciated that the transportation refrigeration unit22can further be operated in reverse to warm the container106when, for example, the outside temperature is very low. In the illustrated embodiment, the return air intake136, the refrigeration unit outlet140, the heat outlet142, and the external air inlet144are configured as grilles to help prevent foreign objects from entering the transportation refrigeration unit22.

The transport refrigeration system200also includes a controller30configured for controlling the operation of the transport refrigeration system200including, but not limited to, the operation of various components of the refrigerant unit22to provide and maintain a desired thermal environment within the refrigerated cargo space119. The controller30may also be able to selectively operate the electric motor26. The controller30may be an electronic controller including a processor and an associated memory comprising computer-executable instructions that, when executed by the processor, cause the processor to perform various operations. The processor may be but is not limited to a single-processor or multi-processor system of any of a wide array of possible architectures, including field programmable gate array (FPGA), central processing unit (CPU), application specific integrated circuits (ASIC), digital signal processor (DSP) or graphics processing unit (GPU) hardware arranged homogenously or heterogeneously. The memory may be a storage device such as, for example, a random access memory (RAM), read only memory (ROM), or other electronic, optical, magnetic or any other computer readable medium.

The transportation refrigeration unit22is powered by the energy management system300or more specifically the energy storage device350, which provides electrical energy to the transportation refrigeration unit22. Examples of the energy storage device350may include a battery system (e.g., a battery, a battery pack, or bank of batteries), fuel cells, flow battery, and others devices capable of storing and outputting electric energy that may be direct current (DC). The energy storage device350may include a battery system, which may employ multiple batteries organized into battery banks. In one embodiment, the energy storage device350may provide electrical energy to the transportation refrigeration unit22and the electric motor324of the vehicle102. In another embodiment, the energy storage device350may provide electrical energy solely to the transportation refrigeration unit22, while the propulsion motor (e.g., the electric motor324and/or the combustion engine320) of the vehicle102receives electrical energy from another source (e.g., the truck energy storage device326.

In current product designs there are typically only two ways to recharge the energy storage device350using only alternating current (AC) sources. Those two ways may include a grid power plug in 400V/3/50HZ (i.e., 400 v, phase 3, 50 Hz) or a 240 VAC input from an axle generator. Unfortunately, it may be very difficult to find a 400V/3/50HZ plug to recharge the energy storage device. Additionally, in current product designs there is no fast charge capability to recharge the energy storage device350to 80% in a few minutes. The embodiments discussed herein seek to address the shortcomings of the current production designs by incorporating the ability to recharge from multiple different charging sources360. This is accomplished through the addition of an input DC-to-DC inverter352and an input AC-to-DC inverter354in the energy management system350. As illustrated inFIG. 1, the energy management system350includes the input AC-to-DC inverter354electrically connected to the energy storage device350and the input DC-to-DC inverter electrically connected to the energy storage device350. The energy management system300also includes an output DC-to-AC inverter370. The output DC-to-AC inverter370electrically connects the energy storage device350to the transportation refrigeration unit22. The output DC-to-AC inverter370is electrically connected to the energy storage device350and the refrigeration unit22.

As illustrated inFIG. 1, the multiple different charging sources360may include a DC Fast charging station361, a DC electrical energy362from the truck energy storage device326, a high voltage 400v/3/50HZ grid364, a low voltage 230V/3/50HZ (i.e., 230 v, phase 3, 50 Hz) grid366, an AC electrical energy inverter ECO-drive368, and an AC electrical energy369from the vehicle alternator322of the vehicle102.

The energy storage device350may be charged by the DC fast charging station361. The energy storage device350is configured to electrically connect to the DC fast charging station361. The DC fast charging station361electrically connects directly to the energy storage device350and does not go through the input DC-to-DC inverter352. The DC fast charging station361may electrically connect directly to the energy storage device350so that the recharging process is managed by DC fast charging station361and not managed by the energy management system300because the power may be too high for an internal charging system of the energy management system300. Advantageously, the DC fast charging station361is configured to charge the energy storage device350to 80% in just a few minutes (e.g., 15-45 minutes depending on a size of the DC fast charging station361and battery cell configuration of the energy storage device350). In an embodiment, the DC fast charging station361electrically connects to the energy storage device350through a fast charging plug382of the energy management system300.

The energy storage device350may be charged by the DC electrical energy362from the truck energy storage device326. The input DC-to-DC inverter353is configured to electrically connect to a truck energy storage device326. The truck energy storage device326electrically connects to the energy storage device350through the input DC-to-DC inverter352. The truck energy storage device326is electrically connected to the input DC-to-DC inverter352.

In an embodiment, the input AC-to-DC inverter354is configured to electrically connect to at least one of a high voltage 400V/3/50HZ grid364, a low voltage 230V/3/50HZ grid366, an AC electrical energy inverter eco-drive368, or a vehicle alternator322.

The energy storage device350may be charged by the high voltage 400v/3/50HZ grid364. The input AC-to-DC inverter354is configured to electrically connect to a high voltage 400V/3/50HZ grid364. The high voltage 400v/3/50HZ grid364electrically connects to the energy storage device350through the input AC-to-DC inverter354. The high voltage 400v/3/50HZ grid364is electrically connected to the input AC-to-DC inverter354. The high voltage 400v/3/50HZ grid364may be an electric vehicle charging station.

The energy storage device350may be charged by the low voltage 230V/3/50HZ grid366. The input AC-to-DC inverter354is configured to electrically connect to the a low voltage 230V/3/50HZ grid366. The low voltage 230V/3/50HZ grid366electrically connects to the energy storage device350through the input AC-to-DC inverter354. The low voltage 230V/3/50HZ grid366is electrically connected to the input AC-to-DC inverter354. The low voltage 230V/3/50HZ grid366may be an electric vehicle charging station.

The energy storage device350may be charged by the AC electrical energy inverter ECO-drive368. The input AC-to-DC inverter354is configured to electrically connect to the AC electrical energy inverter eco-drive368. The AC electrical energy inverter ECO-drive368electrically connects to the energy storage device350through the input AC-to-DC inverter354. The AC electrical energy inverter ECO-drive368is electrically connected to the input AC-to-DC inverter354. In an embodiment, the ECO-drive368consists of translating rotational energy from the combustion engine320, to hydraulic power, which is then converted to electrical power for the transportation refrigeration unit22by a generator.

The DC electrical energy362from the truck energy storage device326may be electrically connected to the input DC-to-DC inverter352via a truck energy storage connection point384, which may be an electrical plug or a wired connection.

The a high voltage 400v/3/50HZ grid364may be electrically connected to the input AC-to-DC inverter354via a high voltage connection point386, which may be an electrical plug or a wired connection.

The a low voltage 230V/3/50HZ grid366may be electrically connected to the input AC-to-DC inverter354via a low voltage connection point388, which may be an electrical plug or a wired connection.

The AC electrical energy inverter ECO-drive368may be electrically connected to the input AC-to-DC inverter354via an EDO-drive connection point392, which may be an electrical plug or a wired connection.

The AC electrical energy369from the vehicle alternator322of the vehicle102may be electrically connected to the input AC-to-DC inverter354via an alternator connection point394, which may be an electrical plug or a wired connection.

An AC electrical energy from a generator transportation unit refrigeration unit diesel engine373may be electrically connected to the input AC-to-DC inverter354via an generator connection point396, which may be an electrical plug or a wired connection. The a generator transportation unit refrigeration unit diesel engine373is not illustrated herein because the transportation refrigeration unit22illustrated herein is an all-electric refrigeration unit The energy storage device350may be charged by the AC electrical energy269from the vehicle alternator322of the vehicle102. The input AC-to-DC inverter354is configured to electrically connect to the vehicle alternator322. The AC electrical energy269from the vehicle alternator322of the vehicle102electrically connects to the energy storage device350through the AC electrical energy269from the vehicle alternator322of the vehicle102. The AC electrical energy269from the vehicle alternator322of the vehicle102is electrically connected to the input AC-to-DC inverter354.

In one embodiment, the energy management system300is located outside of the transportation refrigeration unit22, as shown inFIG. 1. In another embodiment, the energy management system300is located within the transportation refrigeration unit22. The transportation refrigeration unit22has a plurality of electrical power demand loads on the energy storage device350, including, but not limited to, the electric motor26for the refrigerant compression device32, the fan motor42for the fan40associated with the refrigerant heat rejection heat exchanger34, and the fan motor46for the fan44associated with the refrigerant heat absorption heat exchanger38. It is to be understood that, while not required, various power converters52, such as, for example, AC-to-DC rectifiers, DC-to-AC inverters, AC-to-AC voltage/frequency converters, and DC-to-DC voltage converters, may be employed in connection with the energy storage device150as appropriate. In an embodiment, each of the fan motors42,46and the electric motor26may be an AC motor and are thus electrically connected to the energy storage device350through the output DC-to-AC inverter370that is configured to convert the DC electrical energy from the energy storage device to AC electrical energy in a continuous energy output to power the transportation refrigeration unit22. The output DC-to-AC inverter370electrically connects the energy storage device350to the transportation refrigeration unit22.

A power management module310may be configured to control the continuous energy output of the output DC-to-AC inverter370in response to transportation refrigeration unit parameters of the transportation refrigeration unit22. The transportation refrigeration unit parameters may include but are not limited to set point, ambient temperature, delta T° between the temperature in the refrigerated cargo space119and the temperature set point of the transportation refrigeration unit22, airflow rate into or out of the container106, cooling capacity, temperature homogeneity in the container106, doors117opening situation . . . etc. Transportation refrigeration unit parameters, such as delta T° may be important because a high delta T° may indicate that an increase energy is required for pull down or pull up. The power management module310is in electrical communication with the transportation refrigeration unit22and the output DC-to-AC inverter370. The power management module310may also be in electrical communication with the energy storage device350. The power management module310may be configured to control and/or adjust energy output of the output DC-to-AC inverter370in response to parameters of the energy storage device350, including, but not limited to, a state of charge of the energy storage device350a state of health of the energy storage device350, and a temperature of the energy storage device350.

Advantageously by controlling energy output of the output DC-to-AC inverter370in response to parameters of the transportation refrigeration unit22the efficiency of the transportation refrigeration unit22may be improved and the energy consumption of the energy storage device350may be reduced or limited.

In the depicted embodiment, the heater48also constitutes an electrical power demand load. The electric resistance heater48may be selectively operated by the controller30whenever a control temperature within the temperature controlled cargo box drops below a preset lower temperature limit, which may occur in a cold ambient environment. In such an event the controller30would activate the heater48to heat air circulated over the heater48by the fan(s)44associated with the refrigerant heat absorption heat exchanger38. The heater48may also be used to de-ice the return air intake136. Additionally, the electric motor26being used to power the refrigerant compression device32also constitutes a demand load. The refrigerant compression device32may comprise a single-stage or multiple-stage compressor such as, for example, a reciprocating compressor or a scroll compressor. The transport refrigeration system200may also include a voltage sensor28to sense the voltage from the energy storage device350.

It should be appreciated that, although particular components of the energy management system300are separately defined in the schematic block diagram ofFIGS. 1 and 2, each or any of the components may be otherwise combined or separated via hardware and/or software. In one example, while the power management module310is illustrated inFIG. 1as being separate from the transportation refrigeration unit22, in various embodiments, the power management module310may be incorporated into the transportation refrigeration unit22and/or the controller30of the transportation refrigeration unit22. In an embodiment, the power management module310may be a computer program product (e.g., software) encoded within controller30. In another example, while the output DC-to-AC inverter370is illustrated inFIG. 1as being separate from the energy storage device350and the transportation refrigeration unit, in various embodiments, the output DC-to-AC inverter370may be incorporated in the energy storage device350or the transportation refrigeration unit22. In one embodiment, the DC-to-AC variable inverter is incorporated in the energy storage device350. In another embodiment, the output DC-to-AC inverter370is separate from the energy storage device350(i.e., not incorporated in the energy storage device350).

The power management module310may be an electronic controller including a processor and an associated memory comprising computer-executable instructions that, when executed by the processor, cause the processor to perform various operations. The processor may be but is not limited to a single-processor or multi-processor system of any of a wide array of possible architectures, including field programmable gate array (FPGA), central processing unit (CPU), application specific integrated circuits (ASIC), digital signal processor (DSP) or graphics processing unit (GPU) hardware arranged homogenously or heterogeneously. The memory may be a storage device such as, for example, a random access memory (RAM), read only memory (ROM), or other electronic, optical, magnetic or any other computer readable medium.

Referring now toFIG. 3, with continued reference toFIGS. 1 and 2.FIG. 3shows a flow process illustrating a method400of operating a transport refrigeration system200, according to an embodiment of the present disclosure.

At block404, conditioned air is provided to a refrigerated cargo space119using a transportation refrigeration unit22. At block406, DC electrical energy to power the transportation refrigeration unit22is stored using an energy storage device350. At block408, the energy storage device350is charged using at least one of an input DC-to-DC inverter352electrically connected to the energy storage device350, an input AC-to-DC inverter354electrically connected to the energy storage device350, or a DC fast charging station361electrically connected to the energy storage device350.

The method400may also include that the input DC-to-DC inverter352receives electrical energy from the truck energy storage device326. The method400may further include that the AC-to-DC inverter354receives electrical energy from at least one of a high voltage 400v/3/50HZ grid364, a low voltage 230V/3/50HZ grid366, an AC electrical energy inverter ECO-drive368, and an AC electrical energy369from the vehicle alternator322of the vehicle102.

While the above description has described the flow process ofFIG. 3in a particular order, it should be appreciated that unless otherwise specifically required in the attached claims that the ordering of the steps may be varied.

As described above, embodiments can be in the form of processor-implemented processes and devices for practicing those processes, such as processor. Embodiments can also be in the form of computer program code (e.g., computer program product) containing instructions embodied in tangible media, such as floppy diskettes, CD ROMs, hard drives, or any other non-transitory computer readable medium, wherein, when the computer program code is loaded into and executed by a computer, the computer becomes a device for practicing the embodiments. Embodiments can also be in the form of computer program code, for example, whether stored in a storage medium, loaded into and/or executed by a computer, or transmitted over some transmission medium, loaded into and/or executed by a computer, or transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via electromagnetic radiation, wherein, when the computer program code is loaded into an executed by a computer, the computer becomes an device for practicing the exemplary embodiments. When implemented on a general-purpose microprocessor, the computer program code segments configure the microprocessor to create specific logic circuits.