Patent Publication Number: US-11050260-B2

Title: Smart main electrical panel for energy generation systems

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/376,318, filed on Aug. 17, 2016, which is incorporated by reference herein. 
    
    
     BACKGROUND 
     In recent years, climate change concerns, reduction in costs, governmental initiatives, and other factors have driven a rapid rise in the adoption of renewable energy generation systems (i.e., systems that generate energy using renewable resources such as solar, wind, fuel cells, geothermal etc.) at residential and non-residential sites. Solar energy generation systems, in particular, have been very popular energy generation systems due to numerous advantages over other renewable sources. 
     Solar energy generation systems include photovoltaic (PV) modules that can generate power from the sun, and can provide the generated power to a utility grid or one or more loads. Some solar energy generation systems can store energy from the PV and/or utility grid in a battery for future use, and can receive power from the utility grid and re-route power to the one or more loads without having to use power generated from the sun or from energy stored in the battery. 
     Inverters in conventional solar energy generation systems typically operate at/produce power levels that are not high enough to power the entire set of loads in the main panel at a customer site. Accordingly, these inverters limit the amount of power provided by the AC grid to the set of loads during grid-tied (on-grid) mode. Additionally, in reduced power circumstances (e.g., when a black-out event occurs or when a relatively low power-rated inverter cannot output enough power to support the entire set of loads at a customer site) the PV system may only provide power to a subset of the entire set of loads (e.g., the loads designated as back-up loads). Accordingly, loads that are not back-up loads will not be able to receive power from the PV system and thus cannot be used. 
     SUMMARY 
     Various embodiments of the disclosure provide an automatic smart transfer switch for enabling the solar energy generation system to directly couple the AC grid to a main electrical panel so that the entire set of loads at a customer site can be serviced by the AC grid without being limited by the inverter in grid-tied (on-grid) mode. Additionally, various embodiments of the disclosure provide a smart main electrical panel for enabling the solar energy generation system to dynamically supply power to an entire set of loads. 
     In some embodiments, an energy generation system includes an energy generation device; an energy generation inverter coupled to the energy generation device and configured to convert direct current (DC) power from the energy generation device to alternating current (AC) power; a battery pack; a storage inverter coupled to the battery pack, where the storage inverter is configured to convert DC power from the battery pack to AC power and to convert AC power into DC power for storing energy into the battery pack; and a smart main electrical panel coupled to receive AC power from at least one of the energy generation inverter, the storage inverter, and a utility grid, where the smart main electrical panel comprises one or more motorized circuit breakers configured to be remotely controlled to manage the power flow to one or more loads. 
     Each motorized circuit breaker can be configured to be remotely switched to enable or interrupt power flow between the storage inverter and the one or more loads. The energy generation system can further include a panel controller configured to remotely control the plurality of motorized circuit breakers. The panel controller can be positioned within the storage inverter. Each motorized circuit breaker can include a sensor configured to monitor power usage from a respective load of the one or more loads. The panel controller can be configured to receive feedback information from the sensor. The panel controller can be further configured to manage the operation of the plurality of motorized circuit breakers based upon the feedback information. In certain embodiments, the energy generation system further includes an automatic smart transfer switch coupled between the storage inverter and the smart main electrical panel. The automatic smart transfer switch can be configured to switch between a first position and a second position, where the automatic smart transfer switch couples the utility grid to the smart main electrical panel in the first position, and couples the storage inverter to the smart main electrical panel in the second position. 
     In some embodiments, an energy generation system includes an energy generation device; a battery pack; an inverter power control system coupled to the energy generation device and the battery pack, where the inverter power control system is configured to convert power from the energy generation device and the battery pack; and a smart main electrical panel coupled to receive power from the inverter power control system or a utility grid, where the smart main electrical panel comprises one or more motorized circuit breakers configured to be remotely controlled to manage the power flow to one or more loads. 
     Each motorized circuit breaker can be configured to be remotely switched to enable or interrupt power flow between the inverter power control system and the one or more loads. The energy generation system can further include a panel controller configured to remotely control the plurality of motorized circuit breakers. Each motorized circuit breaker can include a sensor configured to monitor power usage from a respective load of the one or more loads. The panel controller can be configured to receive feedback information from the sensor. The panel controller can be further configured to manage the operation of the plurality of motorized circuit breakers based upon the feedback information. In certain embodiments, the energy generation system can further include an automatic smart transfer switch coupled between the inverter power control system and the smart main electrical panel. The automatic smart transfer switch can be configured to switch between a first position and a second position, where the automatic smart transfer switch couples the utility grid to the smart main electrical panel in the first position, and couples the inverter power control system to the smart main electrical panel in the second position. 
     In some embodiments, a circuit breaker for an energy generation system includes a motorized switch configured to be remotely opened and closed based on a control signal, the motorized switch comprising a first end and a second end, where the first end is configured to receive power from an inverter and the second end is configured to output power to a load circuit through an output line; a sensor configured to measure an amount of power flow through the output line; and a feedback line coupled between a panel controller and the sensor, where the feedback line provides an avenue through which the measured amount of power flow may be received by the panel controller. 
     The panel controller can be configured to remotely control the plurality of motorized circuit breakers. The panel controller can be further configured to manage the operation of the motorized switch based upon the measured amount of power flow. 
     A better understanding of the nature and advantages of embodiments of the present invention may be gained with reference to the following detailed description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a conventional AC-coupled energy storage system. 
         FIG. 2  is a block diagram illustrating a conventional DC-coupled energy storage system. 
         FIG. 3  is a block diagram illustrating an exemplary AC-coupled solar energy generation system with an automatic smart transfer switch, according to some embodiments of the present disclosure. 
         FIG. 4  is a block diagram illustrating an exemplary DC-coupled energy storage system with an automatic smart transfer switch, according to some embodiments of the present disclosure. 
         FIG. 5  is a block diagram illustrating an exemplary AC-coupled solar energy generation system with a smart main electrical panel, according to some embodiments of the present disclosure. 
         FIG. 6  is a block diagram illustrating an exemplary DC-coupled solar energy generation system with a smart main electrical panel, according to some embodiments of the present disclosure. 
         FIG. 7  is a block diagram illustrating an exemplary AC-coupled solar energy generation system with an automatic smart transfer switch and a smart main electrical panel, according to some embodiments of the present disclosure. 
         FIG. 8  is a block diagram illustrating an exemplary DC-coupled solar energy generation system with an automatic smart transfer switch and a smart main electrical panel, according to some embodiments of the present disclosure. 
         FIG. 9  is a block diagram illustrating an exemplary motorized circuit breaker, according to some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Solar energy generation systems according to embodiments of the disclosure can directly couple a utility grid to loads at an installation site. In such energy generation systems, an automatic smart transfer switch can be implemented between the inverter and both the utility grid and the loads at the installation site. The automatic smart transfer switch can be configured to select between the inverter and the utility grid to connect to the loads at the installation site. When the automatic smart transfer switch selects the utility grid to connect to the loads during on-grid mode, the utility grid may be directly connected to the loads while the off-grid output of the inverter is isolated. Thus, the inverter cannot limit the power provided to the loads by the utility grid during on-grid mode, but can still feed energy from PV and/or battery to the AC grid during off-grid mode. This is unlike conventional energy generation systems that limit the power provided by the utility grid, as will be discussed further herein. 
     I. PV Systems 
     A conventional solar energy generation system includes an energy generation device, e.g., an array of PV modules connected together on one or more strings, for generating DC power from the sun, one or more PV string inverters for converting the DC power from the strings to AC power, and physical interfaces for feeding into the utility grid and/or off-grid outputs—typically on the load side of the utility meter, between the meter and the customer&#39;s main electrical panel. The conventional solar energy generation system provides excess AC power/energy back to the utility grid, resulting in cost benefits to the customer or resulting in a source of grid services. The conventional solar energy generation system can also route power from the utility grid to one or more loads through the inverter at the customer site separated in a back-up load panel. Conventional solar energy generation systems, however, limit the amount of power provided by the utility grid to all of the loads or the backed-up loads at the customer site, as the power passes through the inverter limited by the power ratings of the inverter&#39;s internal components. There are two types of conventional energy generation systems: an AC-coupled energy generation system and a DC-coupled energy generation system. 
       FIG. 1  illustrates a block diagram of conventional AC-coupled energy storage system  100 . The energy generation system is called an AC-coupled energy generation system because a PV inverter and a storage inverter are coupled at the AC side of each inverter. As shown, AC-coupled energy storage system  100  is a PV system that includes PV array(s)/strings  102  for generating DC power and PV grid-tied string inverter  104  for converting the generated DC power to AC power for feeding into AC utility grid  106  at the interface for back-up loads  108 . PV array  102  may be a single PV module or one or more array/string of PV modules capable of generating DC voltage from photons emitted from a light source such as the sun. Inverter  104  may include DC-to-DC (buck and/or boost) converter  108  for stepping up/down the received DC power from PV array  102  to a suitable level for inversion, and DC-to-AC inverter  110  for converting the DC power to AC power for outputting to AC grid  106 . Inverter  104  may also include capacitor bank  107  coupled between power lines routing power from DC-to-DC converter  108  to DC-to-AC inverter  110  for power stabilization purposes. In some embodiments, the DC-to-DC conversion may take place on the roof in the form of PV optimizers. In certain embodiments where strings of PV modules are long enough to provide high voltage sufficient for conversion on their own, only a DC-to-AC inverter may be implemented in PV system  100 . The micro-inverter may include a DC-to-DC converter and a DC-to-AC inverter, and may be installed on the roof instead of PV string inverter  104 . 
     PV system  100  may also include battery pack  114  for storing and discharging power/energy. Battery pack  114  may be any lead-acid or advanced lead-acid or lithium-ion or flow battery or organic battery pack and the like. Power discharged from battery pack  114  may be provided to storage inverter  116 , which may include DC-to-DC converter  118  for stepping up/down DC voltage provided by battery pack  114  to a suitable level for inversion during charging/discharging processes. DC-to-DC converter  118  may be a buck and/or boost converter that is implemented when battery pack  114  does not include a separate DC-to-DC buck and/or boost converter. In some embodiments, DC-to-DC converter  118  may still be required in storage inverter  116  if the DC-to-DC buck and/or boost converter inside battery pack  114  is not sufficient to match the conversion voltage of storage inverter  116 . Storage inverter  116  may also include DC-to-AC inverter  120  for converting the DC power from battery pack  114  to AC power for outputting to AC grid  106  or one or more back-up loads  108 . Storage inverter  116  may also include capacitor bank  109  coupled between power lines routing power from DC-to-DC converter  118  to DC-to-AC inverter  120  for power stabilization purposes. Anti-islanding relays  126  and  128  may be implemented within PV inverter  104  and storage inverter  116 , respectively, to direct power between inverters  104  and  116  and AC grid  106 . Transfer relays  124  may be implemented within storage inverter  116  to direct power between inverter  116  and either AC grid  106  or back-up loads  108 . In various embodiments, when transfer relays  124  are in a first position, storage inverter  116  may provide power to or receive power from AC grid  106 , and when transfer relays are in a second position, storage inverter  116  may provide power to back-up loads  108  in off-grid (voltage source) operation, e.g., when the utility grid is not available. In the second position, the PV inverter may provide AC power to the storage inverter to charge the battery through the back-up loads interface. 
     Another newer type of conventional PV system is a DC-coupled energy storage system as shown in  FIG. 2 , which illustrates a block diagram of conventional DC-coupled energy storage system  200 . This energy generation system is called a DC-coupled energy generation system because a battery pack and a PV array are coupled to the DC side of an inverter. DC-coupled energy storage system  200  is a PV system that includes PV array(s)/string(s)  202  for generating DC power and inverter power control system (PCS)  204  for converting the generated DC power to AC power for outputting to AC grid  214  or back-up loads  216 . Instead of having two separate inverters, as shown in  FIG. 1 , system  200  may only have a single inverter PCS that is configured to control the flow of power between DC sources, e.g., PV array  202  and battery pack  210 , and AC output destinations, e.g., AC grid  214  and back-up loads  216 . Similar to transfer relays  124  in  FIG. 1 , transfer relays  224  may determine which output destination will receive power from inverter PCS  204 . In various embodiments, when transfer relays  224  are in a first position, inverter PCS  204  may provide power to or receive power from AC grid  214 , and when transfer relays  224  are in a second position, inverter PCS  204  may provide power to back-up loads  216 . Anti-islanding relays  226  may be implemented within PV inverter PCS  204  to direct power from/to AC grid  214 . 
     Inverter PCS  204  may include DC-to-DC (buck and/or boost) converter  206  for ensuring that the voltage provided to DC-to-AC inverter  208  is sufficiently high for inversion. In some embodiments, the DC-to-DC conversion may take place on the roof in the form of PV optimizers. In certain embodiments where strings of PV modules are long enough to provide high voltage sufficient for conversion on their own, only a DC-to-AC inverter may be implemented in PV system  200 . Inverter PCS  204  also includes a DC link bus attached to battery pack  210  so that the DC power coming from PV array  202  can be used to deliver DC power to battery pack  210 . The DC link bus is represented by capacitor bank  207  shown between the two DC-to-DC converters  206  and  212  and DC-to-AC inverter  208  in  FIG. 2 . Battery pack  210  may have a minimum and maximum associated operating voltage window. Because battery pack  210  has a maximum exposed input voltage limit that, in many cases, may be lower than the theoretical maximum DC voltage coming off of the strings (open circuit voltage), a buck-boost circuit  206  or  212  may be implemented between the string-level PV input of inverter PCS  204  and the DC-link connection to battery pack  210 . The inclusion of buck-boost circuit  206  or  212  will prevent battery pack  210  from being exposed to voltages above a safe threshold, thereby eliminating the possibility of damage to battery pack  210  from overvoltage stress. For instance, when DC-to-DC converter  206  is only a boost converter, then DC-to-DC converter  212  may be a buck-boost converter for preventing battery pack  210  from overvoltage stress and provides flexibility in operating voltage range. However, if DC-to-DC converter  206  is a buck and boost converter, then DC-to-DC converter  212  may not be needed. Further details of energy generation system  200  can be referenced in U.S. patent application Ser. No. 14/798,069, filed on Jul. 13, 2015, entitled “Hybrid Inverter Power Control System for PV String, Battery, Grid and Back-up Loads,” where is herein incorporated by reference in its entirety for all purposes 
     Back-up loads, e.g., back-up loads  108  and  216  in  FIGS. 1 and 2 , respectively, discussed herein above may be an entire set, or a subset of the entire set, of loads for a customer site. For instance, back-up loads may be certain loads that are considered to be more important that other loads during power outage. As an example, for a residential customer site, back-up loads may be a refrigerator, air conditioning unit, heater unit, and other loads important for human survival, whereas loads that are not considered back-up loads—but are still part of the entire set of loads—include a television set, a desk lamp, a nightstand light, and the like. For a commercial customer site, back-up loads may be a server bay, information technology infrastructure devices, and other loads important for business sustainability during a power outage, whereas loads that are not considered back-up loads  108  and  216  may be hallway lights, bathroom lights, desk lamps, and the like. In some embodiments, back-up loads may be included in a main panel (not shown) that houses connections for the entire set of loads for a customer site. In other embodiments, back-up loads may be included in a separate load panel (not shown) beside the main panel. 
     Inverters in solar energy generation systems typically operate at power levels that are high enough to provide a sufficient amount of power for all/some of the back-up loads but not high enough to power the entire set of loads at a customer site. These operating power levels are lower than the levels that can be provided by the AC grid and thus limit the amount of power provided by the AC grid to the set of loads during grid-tied (on-grid) mode. For instance, during on-grid mode when AC power is available from the AC grid, the AC power is first provided to the inverter, e.g., storage inverter  116  and PV inverter PCS  204  in  FIGS. 1 and 2 , respectively, and then relayed through the inverter to the back-up loads. Because power to the back-up loads needs to go through the inverter, the amount of power provided by the AC grid to the back-up loads is limited by the operating current/power limits of the storage inverter/inverter PCS which are limited by the ratings of the storage inverter/inverter PCS internal components like switches, relays, wiring, and the like. 
     II. PV Energy Generation System with an Automatic Smart Transfer Switch 
     According to embodiments of the present disclosure, a solar energy generation system is implemented with an automatic smart transfer switch for enabling the solar energy generation system to directly couple the AC grid to a main electrical panel so that the entire set of loads at a customer site can be serviced by the AC grid without being limited by the inverter in grid-tied (on-grid) mode. During on-grid mode (e.g., when power is being provided by the AC grid), the automatic smart transfer switch may isolate the inverter AC back-up (off-grid) output so that the power from the AC grid can be directly provided to the entire set of loads at the customer site. During this time, the output power of the inverter to the AC grid may still be active. During off-grid mode (e.g., when power is not available from the AC grid, such as when a blackout/outage occurs), the automatic smart transfer switch may disconnect the main electrical panel from the AC grid and connect the main panel to the inverter AC back-up (off-grid) output to receive power from either the PV modules and/or the battery in the solar energy generation system. 
       FIG. 3  illustrates exemplary AC-coupled solar energy generation system  300  with automatic smart transfer switch  328 , according to embodiments of the present disclosure. Energy generation system  300  includes PV array  302  for generating DC power and PV inverter  304  for receiving the generated DC power and converting the generated DC power to AC power. Additionally, energy generation system  300  includes a battery pack  314  for storing power from or providing power to storage inverter  316 . Battery pack  314  may include one or more battery cells, a battery management system (BMS), a DC-to-DC buck and/or boost converter, or any combination thereof. According to embodiments of the present disclosure, automatic smart transfer switch  328  may be positioned to route power between storage inverter  316  and both main electrical panel  330  and AC grid  306 . For instance, automatic smart transfer switch  328  may be positioned between inverter  316  and both main electrical panel  330  and AC grid  306 . Main electrical panel  330  may be a physical interface from which an entire set of loads may receive power from inverter  316  or AC grid  306 . The entire set of loads include back-up loads  336  and other on-site loads  338 , which may include those loads that are not considered to be back-up loads. In some embodiments, there may be multiple PV inverters and/or multiple storage inverters and/or multiple battery packs possible for providing more back-up power and/or energy to the loads in main electrical panel  330  or utility grid. 
     Automatic smart transfer switch  328  may be configured to select between two inputs for connecting to an output. For example, automatic smart transfer switch  328  may select between inverter  316  and AC grid  306  to connect to main electrical panel  330  for providing power to loads at a customer site. As shown in  FIG. 3 , automatic smart transfer switch  328  may have two positions: position  1  and position  2 . Depending on the position of automatic smart transfer switch  328 , main electrical panel  330  may be coupled to inverter  316  or AC grid  306 . In some embodiments, the switch may have three positions, where the third position is such that main electrical panel  330  is completely isolated (e.g., not connected to any component). In certain embodiments, automatic transfer switch  328  may also be operated as a manual switch. In some embodiments, when there are multiple storage inverters and/or batteries, the switch may combine or have more positions for multiplexing (combining) the total power/energy from multiple inverters in order to power more loads in the main electrical panel. 
     For instance, when automatic smart transfer switch  328  is in position  1 , AC grid  306  may be coupled to main electrical panel  330  to provide power to main electrical panel  330 . Unlike conventional solar energy generation systems that limit the power provided by an AC grid by routing power from the AC grid to back-up loads through an inverter, solar energy generation system  300  may instead connect AC grid  306  directly to main electrical panel  330  without having to go through inverter  316 . Accordingly, the power from AC grid  306  may be provided to the entire loads set in the main electrical panel  330  so that both back-up loads  336  and on-site loads  338  may receive sufficient power without any impedance from inverter  316 . 
     In additional embodiments, storage inverter  316  also does not limit the power provided by AC grid  306  to main electrical panel  330  even though storage inverter  316  may be coupled to AC grid  306  through AC output/input line  332 . The direct connection between AC grid  306  and main electrical panel  330  allows power to bypass storage inverter  316  and directly flow from AC grid  306  to main electrical panel  330  to power back-up loads  336  and on-site loads  338 . In some embodiments, AC output/input line  332  provides an avenue through which power may flow to battery pack  314  for storing energy from AC grid  306 . 
     When AC grid  306  is no longer available, such as when a blackout/outage occurs, automatic smart transfer switch  328  may move to position  2  where inverters  304  and  316  connect with main electrical panel  330  through AC back-up output  333  so that power generated from PV array  302  and/or power provided by battery pack  314  may be used to power the entire set of loads/proportional loads coupled to main electrical panel  330 . Automatic smart transfer switch  328  may disconnect main electrical panel  330  from AC grid  306  when it is in position  2 . Because PV inverter  304  and storage inverter  316  operate at power levels insufficient for powering all loads set in main electrical panel  330 , i.e., both on-site loads  338  and back-up loads  336  at the same time, only back-up loads  336 , or any other portion of the entire set of loads in main electrical panel  330 , may receive power when automatic smart transfer switch  328  is in position  2 . 
     According to embodiments of the present disclosure, automatic smart transfer switch  328  may be in a default position when AC grid  306  is present, and transfer to an alternative position when AC grid  306  is no longer available. The transitioning between the default position and the alternative positon may occur automatically and in response to the absence of voltage from AC grid  306 . 
     As an example, automatic smart transfer switch  328  may be in position  1  when AC grid  306  is present. Position  1  may be a default position of automatic smart transfer switch  328  when AC grid  306  is present. When AC grid  306  is not available, automatic smart transfer switch  328  may automatically transfer to position  2 , thereby allowing power to be provided to the entire set of loads in main electrical panel  330 , i.e., both back-up loads  336  and on-site loads  338 , from PV array  302  and/or battery pack  314 . Position  2  may be an alternative position of automatic smart transfer switch  328 , the alternative position being a position of automatic smart transfer switch  328  when no external factors are present. The transition may occur automatically upon the loss of AC grid  306 . In some embodiments, automatic transfer switch  328  is powered by AC grid  306  so that when AC grid  306  is available, power can be provided to automatic smart transfer switch  328  to keep it in position  1 ; and when AC grid  306  is not available, power can no longer be provided to automatic smart transfer switch  328  to keep it in position  1  and thus causes automatic smart transfer switch  328  to transition to its alternative position, i.e., position  2 . In such instances, automatic smart transfer switch  328  may be an N-pole dual-throw relay, or switch, or contactor that is spring loaded to be in the alternative position when power is not present. In some embodiments, the automatic transfer switch  428  can be powered from the back-up output of the inverter PCS, and the operational logic for positions  1  and  2  would be opposite to the above embodiment. 
     In another example, the position of automatic smart transfer switch  328  may be designated by a separate device, such as controller  340 . Controller  340  may be coupled to sensor  342  to detect the presence of AC grid  306  and designate the position of automatic smart transfer switch  328  based on whether AC grid  306  is present. For instance, controller  340  may cause automatic smart transfer switch  328  to be in position  1  when controller  340  detects the presence of AC grid  306 ; and may cause automatic smart transfer switch  328  to be in position  2  when controller  340  detects that the presence of AC grid  306  is lost. The presence/loss of AC grid  306  may be detected when a voltage, frequency, or power is sensed/not sensed by sensor  342 . Controller  340  may be positioned within its own separate enclosure, or within main electrical panel  330 , storage inverter  316 , or PV inverter  304 . Controller  340  may be any suitable device capable of being configured to manage the operation of automatic smart transfer switch  328 , such as a microcontroller, application specific integrated circuit (ASIC), field-programmable gate array (FPGA), and the like. Sensor  342  may be any suitable sensor, such as a voltage sensor, for detecting the presence of AC grid  306 . In such embodiments, automatic smart transfer switch  328  may be an N-pole dual-throw electronically-controlled relay. 
     Automatic smart transfer switches discussed herein with respect to  FIG. 3  may not only be implemented in AC-coupled energy storage systems, but also for DC-coupled energy storage systems, as discussed herein with respect to  FIG. 4 .  FIG. 4  illustrates a block diagram of exemplary DC-coupled energy storage system  400  with automatic smart transfer switch  428 , according to embodiments of the present disclosure. Energy generation system  400  includes PV array  402  for generating DC power and inverter PCS  404  for receiving the generated DC power and converting the generated DC power to AC power. Additionally, energy generation system  400  includes battery pack  410  for storing power from and/or providing power to PV inverter PCS  404 . In some embodiments, there may be additional inverter PCSs and/or additional battery packs for providing more back-up power and/or energy to the loads in main electrical panel  430 . In some embodiments, energy storage system  400  may also include a PV inverter or a storage inverter in combination with inverter PCS  404 . Battery pack  410  may include one or more battery cells, a battery management system (BMS), a DC-to-DC buck and/or boost converter, or any combination thereof. In some embodiments, there may be multiple PV inverters and/or multiple storage inverters and/or inverter PCSs and/or multiple battery packs possible for providing more back-up power and/or energy to the loads in main electrical panel  430 . 
     According to embodiments of the present disclosure, energy generation system  400  includes automatic smart transfer switch  428  that is positioned to route power between inverter PCS  404  and both main panel  430  and AC grid  414 . Main electrical panel  430  may be a physical interface from which an entire set of loads may receive power from inverter PCS  404  or AC grid  414 . The entire set of loads include back-up loads  436  and on-site loads  438 , which include those loads that are not considered to be back-up loads. 
     Similar to automatic smart transfer switch  328  in  FIG. 3 , automatic smart transfer switch  428  may be configured to select between two inputs for connecting to an output. For example, automatic smart transfer switch  428  may select between inverter PCS  404  and AC grid  414  to connect to main panel  430  for providing power to loads at a customer site. Automatic smart transfer switch  428  may have two positions: position  1  and position  2 . Depending on the position of automatic smart transfer switch  428 , main panel  430  may be coupled to inverter PCS  404  or AC grid  414 . In some embodiments, automatic smart transfer switch  428  may have three positions, where the third position is such that main electrical panel  430  is completely isolated (e.g., not connected to any component). In certain embodiments, automatic transfer switch  428  may also be operated as a manual switch. 
     When automatic smart transfer switch  428  is in position  1 , AC grid  414  may be coupled to main electrical panel  430  to provide power to main electrical panel  430 . In embodiments, AC grid  414  may be directly coupled to main panel  430  so that power may be provided to main panel  430  from AC grid  414  without having to go through inverter PCS  404 . Accordingly, the full potential of power from AC grid  414  may be provided to main panel  430  so that both back-up loads  436  and on-site loads  438  may receive sufficient power without hindrance from inverter PCS  404  in grid-tied mode (on-grid). According to embodiments, inverter PCS  404  does not limit the power provided by AC grid  414  to main electrical panel  430 . The direct connection between AC grid  414  and main panel  430  allows power to bypass inverter PCS  404  and directly flow from AC grid  406  to main panel  430  to power back-up loads  436  and on-site loads  438 . 
     Similar to automatic smart transfer switch  328  in  FIG. 3 , automatic smart transfer switch  428  may automatically move to position  2  when AC grid  414  is no longer available, e.g., when a blackout occurs. In position  2 , automatic smart transfer switch  428  may couple inverter PCS  404  to main panel  430  through its AC back-up output  433  so that power generated from PV array  402  and/or power provided by battery pack  410  may be used to power loads coupled to main panel  430 . Because PV inverter PCS  404  operates at power levels insufficient for powering both on-site loads  438  and back-up loads  436  at the same time, only back-up loads  436  may receive power when automatic smart transfer switch  428  is in position  2  or a portion of the entire set of loads, i.e., a portion of both back-up loads  438  and on-site loads  438 , may receive power in position  2 . 
     Position  2  may be an alternative position for automatic smart transfer switch  428 , and position  1  may be a default position. Thus, when AC grid  414  is not available, automatic smart transfer switch  428  may automatically transfer to position  2 , thereby allowing power to be provided to the entire set of loads on main electrical panel  430  i.e., back-up loads  436  and on-site loads  438  from PV array  402  and/or battery pack  410 . The transition may automatically occur upon the loss of AC grid  414 . In some embodiments, automatic transfer switch  428  is powered by AC grid  414  so that when AC grid  414  is available, power can be provided to automatic smart transfer switch  428  to keep it in position  1 ; and when AC grid  414  is not available, power can no longer be provided to automatic smart transfer switch  428  to keep it in position  1  and thus causes automatic smart transfer switch  428  to transition to its alternative position, i.e., position  2 . In some embodiments, the automatic transfer switch  428  can be powered from the output of the inverter PCS for the back-up loads, and the logic for positions  1  and  2  would be opposite to the above embodiment. In some embodiments, when there are multiple inverter PCSs and/or battery packs, the switch may combine or have more positions for multiplexing the total power/energy from multiple inverters in order to power more loads in the main electrical panel. 
     In other embodiments, the position of automatic smart transfer switch  428  may be designated by a separate device, such as controller  440 . Controller  440  may be coupled to sensor  442  to detect the presence of AC grid  414  and designate the position of automatic smart transfer switch  428  based on whether AC grid  414  is present. For instance, controller  440  may cause automatic smart transfer switch  428  to be in position  1  when controller  440  detects the presence of AC grid  414 ; and may cause automatic smart transfer switch  428  to be in position  2  when controller  440  detects that the presence of AC grid  414  is lost. Controller  440  may be positioned within its own separate enclosure or within main panel  430  or in inverter PCS  404 . Similar to controller  340  in  FIG. 3 , controller  440  may be any suitable device capable of being configured to manage the operation of automatic smart transfer switch  428 , such as a microcontroller, application specific integrated circuit (ASIC), field-programmable gate array (FPGA), and the like for receiving sensor information and for performing computations. Controller  440  may communicate via wired or wireless communication lines to inverter  404  and main electrical panel  430 . And similar to sensor  342  in  FIG. 3 , sensor  442  may be any suitable sensor for detecting the presence of AC grid  414 . 
     Similar to automatic smart transfer switch  328  in  FIG. 3 , automatic smart transfer switch  428  may be an N-pole dual throw relay, or switch, or contactor that is spring loaded to be in an alternative position when power is not present, or an N-pole dual-throw electronically-controlled relay. 
     It is to be appreciated that PV inverter  304 , storage inverter  316 , and inverter PCS  404  in  FIGS. 3 and 4  can be any type of inverter for any phase grid. As an example, inverters  304 ,  316 , and  404  may be single phase inverters for operating with a single phase utility grid and single phase loads. In other examples, inverters  304 ,  316 , and  404  may be multi-phase inverters for operating with a multi-phase utility grid and multi-phase loads. In some embodiments, at least one of inverters  304 ,  316 , and  404  is a three-phase inverter for operating in a three-phase power system including a three-phase and/or multi-phase loads. 
     III. PV Energy Generation Systems with a Smart Main Electrical Panel 
     As discussed herein, conventional PV systems, e.g., PV systems  100  and  200  in  FIGS. 1 and 2 , respectively, can provide power to back-up loads for a customer site. The back-up loads may include circuits that use power, such as a refrigerator, a washer/dryer, an air conditioning unit, and the like. The power lines that provide power to the circuits are hardwired to an electrical panel at the customer site and not easily reconfigured. 
     In reduced power circumstances (e.g., when a black-out event occurs or when a low power-rated inverter cannot output enough power to support the entire set of loads at a customer site) the PV system may only provide power to a subset of the entire set of loads (e.g., the loads designated as back-up loads). Accordingly, loads that are not back-up loads will not be able to receive power from the PV system and thus cannot be used. 
     According to embodiments of the present disclosure, a solar energy generation system is implemented with a smart main electrical panel for enabling the solar energy generation system to dynamically supply power to an entire set of loads. Being able to dynamically supply power means being able to adjust which circuits are to receive power in real time. For instance, the smart main electrical panel can dynamically adjust power flow to different loads at the customer site in response to power demand. This enables the smart main electrical panel to provide power to all of the circuits at the customer site, thereby eliminating the need for having to designate a set of back-up loads or a separate load panel. In some embodiments, the smart main electrical panel may be able to reconfigure distribution of power according to one or more circuit breaker profiles and/or a priority list. Each circuit breaker profile may be a predetermined set of circuits that are to be connected to the PV and storage system to receive power. Being able to adjust which circuits are to receive power in real time allows the PV and storage system to supply power to the entire set of loads in a piecemeal fashion, even though the output power is not sufficient to supply power to the entire set of loads at the same time. This also eliminates possibility of overload situations. 
       FIG. 5  illustrates exemplary AC-coupled solar energy generation system  500  with smart main electrical panel  540 , according to embodiments of the present disclosure. Energy generation system  500  includes PV array  502  for generating DC power and PV inverter  504  for receiving the generated DC power and converting the generated DC power to AC power. Additionally, energy generation system  500  includes battery pack  514  for storing power from or providing power to storage inverter  516 . Battery pack  514  may include one or more battery cells, a battery management system (BMS), a DC-to-DC buck and/or boost converter, or any combination thereof. PV inverter  504  and storage inverter  516  may be configured similar to the respective components of PV inverter  104  and storage inverter  116  in  FIG. 1 . In some embodiments, there may be multiple PV inverters and/or multiple storage inverters and/or multiple battery packs for providing more back-up power and/or energy to entire set of loads  538 . Entire set of loads  538  may include all of the circuits operated at the customer site, such as an air conditioning unit, refrigerator, lamps, recessed lights, consumer electronics, and the like, without designation between on-site and back-up loads. 
     Smart main electrical panel  540  may be a physical interface to which entire set of loads  538  may couple to receive power from storage inverter  516  or AC grid  506 . Smart main electrical panel  540  may include interfaces for entire set of loads  538 , thus PV system  500  does not need a separate back-up panel in addition to the smart main electrical panel  540 . According to some embodiments of the present disclosure, smart main electrical panel  540  may include a plurality of motorized circuit breakers  534  for coupling respective circuits in entire set of loads  538  to storage inverter  516  or AC grid  506 . 
     In general, conventional circuit breakers are electrical switches designed to protect an electrical circuit from damage caused by overload or short circuit. Its function is to interrupt power flow after a default is detected. Generic circuit breakers can be manually reset by hand to resume the power flow, and may also be manually switched to interrupt power flow if desired. Switching of these circuit breakers requires a person to manually switch the position of the circuit breakers. Unlike generic circuit breakers, however, motorized circuit breakers  534  according to embodiments of the present disclosure may be remotely reset without direct manual interaction by a person. For instance, a mechanical device may be coupled to a circuit breaker switch and configured to move the circuit breaker switch to reset or interrupt the power flow. According to some embodiments of the present disclosure, more than one motorized circuit breakers  834  can be remotely switched at a time to interrupt or establish power flow, as will be discussed further herein. In some embodiments, the motorized circuit breakers could be mechanical relays or contactors or mechanical switches. 
     In some embodiments, the switching of motorized circuit breakers  534  may be controlled by a controller, such as panel controller  542 . Panel controller  542  can send electrical signals to specific motorized circuit breakers  534  to either interrupt or establish their power flow. In order for panel controller  542  to control motorized circuit breakers  534 , wired or wireless communication lines (not shown for clarity purposes) may be coupled between panel controller  542  and each motorized circuit breaker  534 . Any suitable wired communication lines, e.g., RS485, controller area network (CAN) bus, and the like, and any suitable wireless communication lines, e.g., wireless fidelity (WiFi), Zigbee, radio, and power line communication (PLC), can be used. A mobile application interface can, in some embodiments, enable a customer to command panel controller  542  to send electrical signals to the specific motorized circuit breakers  534 . In certain embodiments, panel controller  542  may be any suitable device capable of being configured to control the switching of motorized circuit breakers  534 . For example, panel controller  542  may be a microcontroller, ASIC, FPGA, and the like. Panel controller  542  may be positioned within storage inverter  516  as shown in  FIG. 5 ; however, embodiments are not limited to such configurations. Panel controller  542  may be positioned within either of PV inverter  504  and smart main electrical panel  540  or in a separate external enclosure, as long as panel controller  542  can control motorized circuit breakers  534  according to embodiments of the present disclosure. 
     Panel controller  542  can be configured to switch a group of motorized circuit breakers  534  to a position that enables power flow. The group of motorized circuit breakers  534  may be determined by a circuit breaker profile. Exemplary PV system  500  in  FIG. 5  shows two circuit breaker profiles: first circuit breaker profile  544  and second circuit breaker profile  546 . Each circuit breaker profile includes a different predetermined group of motorized circuit breakers  534 . In some cases, two circuit breaker profiles may have one or more motorized circuit breakers that are the same. In some embodiments, the circuit breakers could be single pole (for example: 110/120V), two-pole (for example: 208/220/230/240V), or multi-pole circuit breakers. 
     The selection of motorized circuit breakers  534  in each circuit breaker profile is based on a particular circumstance that it is designed to address. For instance, one circuit breaker profile, e.g, first circuit breaker profile  544 , may be designed for instances where grid power is unavailable, such as during a black-out event. In such instances, first circuit breaker profile  544  may include a group of motorized circuit breakers  534  corresponding to circuits necessary for human survival. Thus, when a black-out event occurs, panel controller  542  may switch motorized circuit breakers  534  to enable power flow according to first circuit breaker profile  544 . Panel controller  542  may, at the same time, switch all other motorized circuit breakers  534  to interrupt power flow. 
     Another circuit breaker profile, e.g., circuit breaker profile  546 , may be for instances where there is limited grid or back-up power (e.g., due to a low power rating inverter as discussed herein with respect to  FIG. 1 , or for any other reason) and the customer wants to use a power-intensive entertainment system. In such cases, second circuit breaker profile  546  may include a group of motorized circuit breakers  534  that correspond to circuits for the operation of the entertainment system. Thus, when the customer indicates a desire to use the entertainment system, panel controller  542  may switch the group of motorized circuit breakers  534  to enable power flow according to second circuit breaker profile  546 , and may, at the same time, switch all other motorized circuit breakers  534  to interrupt power flow. By only allowing power to flow to the entertainment system and interrupting power flow to other circuits not related to the entertainment system, the other circuits may not unnecessarily draw power and reduce the amount of power available to the entertainment system. 
     In some embodiments, panel controller  542  may independently control the switching of motorized circuit breakers  534  according to a circuit breaker profile. For example, panel controller  542  may include a memory bank (not shown) containing lines of computer code that, when executed, switches motorized circuit breakers  534  according to a selected circuit breaker profile determined by an algorithm. The algorithm may be created by a technician during manufacturing and/or during installation of PV system  500  or by the customer himself via a mobile application. In additional or alternative embodiments, panel controller  542  may be communicatively coupled to an external device that can send commands to panel controller  542  to switch motorized circuit breakers  534  according to a circuit breaker profile. As an example, a mobile device, such as a customer&#39;s smart phone, may send a command to panel controller  542  to switch specific motorized circuit breakers  534  according to a circuit breaker profile selected by the customer through the smart phone. 
     In additional embodiments, panel controller  542  may operate the switching of motorized circuit breakers  534  according to a priority list. Some circuits may have a higher priority than other circuits given the importance of the function of the circuit. Thus, motorized circuit breakers  534  corresponding to the circuits that have higher priorities may be switched to allow power flow over other motorized circuit breakers  534  corresponding to circuits that have lower priorities. For example, when a microwave oven or a stove is drawing power, motorized circuit breakers  534  for a washer and/or dryer can be switched in a position that interrupts power flow. Likewise, when the microwave or a stove is not drawing power, motorized circuit breakers  534  for the washer and/or dryer can be switched in a position that allows power flow. The list of priorities may be programmed within panel controller  542  by a technician during manufacturing or installation of PV system  500 , or may be controlled by a customer after installation of PV system  500  via an external device. 
     Once the selected motorized circuit breaker profiles  534  are switched to allow power flow, power from storage inverter  516 , PV inverter  504 , and/or AC grid  506  may be provided to corresponding circuits of entire set of loads  538 . In certain embodiments, during on-grid mode, all of the power from AC grid  506  first flows to storage inverter  516  and then flows to smart main electrical panel  540  before being outputted to loads  538 . In some embodiments, power may flow from PV inverter  504  and/or storage inverter  516  as back-up output  533  to central back-up output circuit breaker  538 . From there, power may then flow to motorized circuit breakers  534 . Only those motorized circuit breakers  534  that are switched to allow power flow may enable power to flow from storage inverter  516  to the respective circuits in entire set of loads  538 . In additional embodiments, power may flow from AC grid  506  to the respective circuits in entire set of loads  538  through the selected motorized circuit breakers  534 . In such embodiments, power may first flow through utility back-feed breaker  536 , storage inverter  516 , central back-up output circuit breaker  538 , and then to the respective circuits in entire set of loads  538 . 
     As can be appreciated herein, energy generation systems that have smart main electrical panels can enable the solar energy generation system to supply power to a dynamic set of loads. Thus, the entire set of loads can be serviced by the energy generation system even in reduced power situations. 
     It is to be appreciated that a smart main electrical panel may be incorporated in conventional DC-coupled solar energy generation systems as well. For instance,  FIG. 6  illustrates exemplary DC-coupled solar energy generation system  600  with smart main electrical panel  640 , according to embodiments of the present disclosure. Energy generation system  600  includes PV array  602  for generating DC power, battery pack  610  for storing energy, and PV hybrid inverter PCS  604  for receiving the generated DC power and converting the generated DC power to AC power. Hybrid inverter PCS  604  may be similar in operation and construction to inverter PCS  204  in  FIG. 2 . 
     Smart main electrical panel  640  may be a physical interface from which entire set of loads  638  may receive power from hybrid inverter PCS  604  or AC grid  606 . According to embodiments, smart main electrical panel  640  may include motorized circuit breakers  633  for remotely controlling the power flow to circuits in entire set of loads  638 . Thus, in limited power situations, e.g., when a low power-rated inverter limits the amount of power provided by an AC grid, or when a black-out event occurs, smart main electrical panel  640  may dynamically adjust the power flow to those circuits in entire set of loads  638  that need power. Operations of smart main electrical panel  640  may be similar to the operations of smart main electrical panel  540  in  FIG. 5 . 
     While smart main electrical panels may be incorporated in conventional PV systems, it is to be appreciated that these smart main electrical panels may also be incorporated in any other suitable PV system. For instance, smart main electrical panels may also be incorporated into PV systems with automatic smart transfer switches, such as PV systems  300  and  400  discussed herein with respect to  FIGS. 3 and 4  herein. 
       FIG. 7  illustrates a block diagram of exemplary AC-coupled solar energy generation system  700  with automatic smart transfer switch  728  and smart main electrical panel  740 , according to embodiments of the present disclosure. Automatic smart transfer switch  728  may be positioned between storage inverter  716  and smart main electrical panel  740 . In some embodiments, automatic smart transfer switch  728  transition between position  1  and position  2  so that power from AC grid  706  may not be limited by the power rating of storage inverter  716 , for similar reasons discussed herein with respect to  FIG. 3 . Smart main electrical panel  740  may include motorized circuit breakers  733  for remotely controlling the power flow to circuits in entire set of loads  738 . Thus, in limited power situations, e.g., when a black-out event occurs, smart main electrical panel  740  may dynamically adjust the power flow to those circuits in entire set of loads  738  that need power. Operations of smart main electrical panel  740  may be similar to the operations of smart main electrical panel  540  in  FIG. 5 . 
     When automatic smart transfer switch  728  is in position  1 , storage inverter  716  may be electrically isolated so that power may flow from AC grid  706  directly to entire set of loads  738  through automatic smart transfer switch  728 . In this case, all circuits in entire set of loads  738  may be supplied power from AC grid  706 . However, when automatic smart transfer switch  728  is in position  2 , such as when a black-out/outage event occurs, a limited amount of power may be provided to entire set of loads  738  from PV array  702  and/or battery pack  714 . The limited amount of power may not be sufficient to support all of the circuits in entire set of loads  738 . According to embodiments of the present disclosure, smart main electrical panel  740  may dynamically switch between circuit profiles to provide power to those circuits in entire set of loads  738  that currently need power, thereby enabling the entire set of loads at the customer site to be able to receive power from the energy generation system. Operation of smart main electrical panel  740  is similar to the operation of smart main electrical panel  540  discussed in  FIG. 5 . In some embodiments, when there is no AC grid available, panel controller  842  may use power from battery pack  714  or PV array  702  to operate motorized circuit breakers  733 . 
     According to embodiments, smart main electrical panels may also be implemented in DC-coupled energy generation systems with automatic smart transfer switches.  FIG. 8  illustrates a block diagram of exemplary DC-coupled solar energy generation system  800  with automatic smart transfer switch  828  and smart main electrical panel  840 , according to embodiments of the present disclosure. Automatic smart transfer switch  828  may transition between position  1  and position  2  so that power from AC grid  806  may not be limited by the power rating of hybrid inverter PCS  804 , for similar reasons discussed herein with respect to  FIG. 4 . 
     When automatic smart transfer switch  828  is in position  1 , back-up output  833  of storage inverter  804  may be electrically isolated so that power may flow from AC grid  806  directly to entire set of loads  838  through automatic smart transfer switch  828 . However, when automatic smart transfer switch  828  is in position  2 , a limited amount of power may be provided to entire set of loads  838  from PV array  802  and/or battery pack  810 . The limited amount of power may not be sufficient to support all of the circuits in entire set of loads  838 . Thus, similar to smart main electrical panel  540  in  FIG. 5 , smart main electrical panel  840  may dynamically switch between circuit profiles to provide power to those circuits in entire set of loads  838  that currently need power, thereby enabling the entire set of loads at the customer site to be able to receive power from the energy generation system. 
     By implementing smart main electrical panels  740  and  840  in energy generation systems  700  and  800 , respectively, power may be provided to all circuits in entire set of loads  838  even when limited power is provided by respective PV arrays and/or battery packs. 
       FIG. 9  illustrates a block diagram of exemplary motorized circuit breaker  902 , according to embodiments of the present disclosure. Motorized circuit breaker  902  may be any one of motorized circuit breakers  534 ,  634 ,  734 , and  834  discussed herein with respect to  FIGS. 5, 6, 7, and 8 , respectively. It is to be appreciated that even though  FIG. 9  illustrates only one motorized circuit breaker, one skilled in the art understands that there may be more than one motorized circuit breaker in smart main electrical panel  904 , and the description discussed in relation to motorized circuit breaker  902  may apply to some, if not all, of the other motorized circuit breakers. Motorized circuit breaker  902  may be housed within smart main electrical panel  904 . In some embodiments, motorized circuit breaker  902  includes a motorized switch  916  for enabling and interrupting power flow. Power flow may be enabled when motorized switch  916  is closed; and power may be interrupted when motorized switch  916  is open. 
     According to embodiments of the present disclosure, the position of motorized switch  916  may be controlled by control signal  914  that is sent from panel controller  919 . As mentioned herein, control signal  914  may be sent via a wired or wireless communication line, e.g., RS232, RS485, CAN, Wi-Fi, Zigbee, Radio frequency, PLC, and the like. Inverter  918  may be any suitable inverter, such as a storage inverter or a hybrid inverter PCS, as discussed herein. 
     Power provided by inverter  918  may be outputted to motorized switch  916  as back-up output  912 . When motorized switch  916  is open, back-up output  912  may not flow to load circuit  920 . However, when motorized switch  916  is closed, back-up output  912  may flow to load circuit  920  through output line  922 . In some embodiments, current/voltage/power sensor  908  may be positioned along output line  922  between motorized switch  916  and load circuit  920  to monitor power flow to load circuit  920 . Measurements made by current/power sensor  908  may be fed back to panel controller  929  as feedback information through feedback line  910 . Accordingly, panel controller  919  may measure the usage of power by load circuit  920 . In some embodiment, the panel controller may have memory for recording the usage of each specific load circuit and optimize the circuit breaker profile or priority from time to time. 
     By enabling panel controller  919  to receive feedback information through feedback line  910 , panel controller  919  may monitor the usage of power to determine periods of high power usage, periods of low power usage, and time of specific loads usage in a day/month/year. This information may be used to fine tune a priority list, or may be used to determine when a certain circuit breaker profile should be implemented. Accordingly, smart main electrical panel  904  can dynamically change the flow of power from inverter  918  to load circuit  920 . 
       FIG. 9  only shows one motorized circuit breaker  902  and only one load circuit  920  for clarity purposes. It is to be appreciated that embodiments are not limited to such configurations and that other configurations may have more motorized circuit breakers and more load circuits. 
     Although the invention has been described with respect to specific embodiments, it will be appreciated that the invention is intended to cover all modifications and equivalents within the scope of the following claims.