Abstract: A converter includes a DC bus, a first DC-DC converter, a second DC-DC converter, and a plurality of circulating current suppression circuits. The first DC-DC converter is coupled to the DC bus and includes a first plurality of switches. The second DC-DC converter is coupled to the DC bus in parallel with the first DC-DC converter. The second DC-DC converter includes a second plurality of switches. The plurality of circulating current suppression circuits are coupled to the DC bus and are further respectively coupled to the first DC-DC converter and the second DC-DC converter. Each of the plurality of circulating current suppression circuits has a resonant frequency at or around a switching frequency for the first and second pluralities of switches. The plurality of circulating current suppression circuits is configured to suppress current at or around the switching frequency and pass at least direct current.

Abstract: A multilevel converter system is provided. The multilevel converter system includes a multilevel converter and a short-circuit protection circuit. The multilevel converter includes a first segment and a second segment electrically connected to the first segment, wherein the first and second segments are each configured to convert a first current to a second current. The first segment includes a plurality of first switches. The second segment includes a plurality of second switches. The short-circuit protection circuit is electrically connected to the multilevel converter, wherein the short-circuit protection circuit includes at least one electrical component that is electrically connected in parallel with at least one of the plurality of first switches and the plurality of second switches. The short-circuit protection circuit is configured to protect the plurality of first switches and the plurality of second switches from a short-circuit current during a short-circuit condition.

Abstract: A converter includes a DC bus, a first DC-DC converter, a second DC-DC converter, and a plurality of circulating current suppression circuits. The first DC-DC converter is coupled to the DC bus and includes a first plurality of switches. The second DC-DC converter is coupled to the DC bus in parallel with the first DC-DC converter. The second DC-DC converter includes a second plurality of switches. The plurality of circulating current suppression circuits are coupled to the DC bus and are further respectively coupled to the first DC-DC converter and the second DC-DC converter. Each of the plurality of circulating current suppression circuits has a resonant frequency at or around a switching frequency for the first and second pluralities of switches. The plurality of circulating current suppression circuits is configured to suppress current at or around the switching frequency and pass at least direct current.

Abstract: A multilevel converter system is provided. The multilevel converter system includes a multilevel converter and a short-circuit protection circuit. The multilevel converter includes a first segment and a second segment electrically connected to the first segment, wherein the first and second segments are each configured to convert a first current to a second current. The first segment includes a plurality of first switches. The second segment includes a plurality of second switches. The short-circuit protection circuit is electrically connected to the multilevel converter, wherein the short-circuit protection circuit includes at least one electrical component that is electrically connected in parallel with at least one of the plurality of first switches and the plurality of second switches. The short-circuit protection circuit is configured to protect the plurality of first switches and the plurality of second switches from a short-circuit current during a short-circuit condition.

Abstract: A control circuit for a power converter is provided. The control circuit includes a pulse width modulator, a current feedback loop, a bus voltage feedforward path, and a logic circuit. The pulse width modulator generates a control signal for the power converter to regulate a load current. The current feedback loop controls the pulse width modulator to converge the load current to a demanded current. The bus voltage feedforward path measures a bus voltage supplied to the power converter at an input bus and, in combination with the current feedback loop, control the pulse width modulator to regulate the load current based on the bus voltage. The logic circuit collects load current measurements and determines, based at least partially thereon, a voltage variation event has occurred on the input bus, and disables the control signal for the power converter in response to determining the voltage variation event has occurred.

Abstract: A power supply system is provided. A power supply system includes a direct current (DC) bus, a first alternating current (AC) bus, at least one modular power conversion unit, and a battery string. The at least one modular power conversion unit includes a high-frequency direct current to alternating current (DC/AC) transformer electrically coupled between the DC bus and the first AC bus, and a direct current to direct current (DC/DC) converter electrically coupled to the high-frequency DC/AC transformer and the DC bus. The DC/DC converter is electrically coupled between the DC bus and the battery string.

Abstract: Controlling an energy storage system includes providing one or more constraints to an optimization problem algorithm, determining by the optimization problem algorithm a DC bus voltage value that results in an minimum total power dissipation for the plurality of power converters, calculating a respective control variable for each of the respective plurality of power converters based on the determined DC bus voltage value, and generating control processor executable instructions to implement control of each of the plurality of power converters to achieve the calculated respective control variable. A system for implementing the method and a non-transitory computer-readable medium are also disclosed.

Abstract: Controlling an energy storage system includes providing one or more constraints to an optimization problem algorithm, determining by the optimization problem algorithm a DC bus voltage value that results in an minimum total power dissipation for the plurality of power converters, calculating a respective control variable for each of the respective plurality of power converters based on the determined DC bus voltage value, and generating control processor executable instructions to implement control of each of the plurality of power converters to achieve the calculated respective control variable. A system for implementing the method and a non-transitory computer-readable medium are also disclosed.

Abstract: Systems and methods for controlling an energy storage system are provided. In one embodiment, a method for controlling an energy storage system includes receiving a power demand associated with a grid service operation for an energy storage system and accessing data indicative of a time shift for responding to the power demand. The method includes implementing the time shift in the power demand to obtain a time shifted power demand; and controlling the charge or discharge of one or more energy storage devices in the energy storage system based at least in part on the time shifted power demand.

Abstract: An energy storage module includes a module housing, a positive polarity module terminal and a negative polarity module terminal accessible via an external surface of the housing, and a plurality of battery cells contained within the housing and coupled in series between the positive polarity terminal and a negative polarity terminal to form a battery cell string. A removable manual service disconnect (MSD) unit is physically coupled to the external surface of the housing and electrically coupled between at least one battery cell in the battery cell string and one of the module terminals. The MSD unit has at least a first MSD operating state to allow current conduction between the positive polarity module terminal and the negative polarity module terminal, and a second MSD operating state to prevent current conduction between the positive polarity module terminal and the negative polarity module terminal.

Abstract: An energy storage module includes a module housing, a positive polarity module terminal and a negative polarity module terminal accessible via an external surface of the housing, and a plurality of battery cells contained within the housing and coupled in series between the positive polarity terminal and a negative polarity terminal to form a battery cell string. A removable manual service disconnect (MSD) unit is physically coupled to the external surface of the housing and electrically coupled between at least one battery cell in the battery cell string and one of the module terminals. The MSD unit has at least a first MSD operating state to allow current conduction between the positive polarity module terminal and the negative polarity module terminal, and a second MSD operating state to prevent current conduction between the positive polarity module terminal and the negative polarity module terminal.

Abstract: A reservoir includes power generation sources and energy storage systems. Some of the energy storage systems have a housing and energy storage devices. The energy storage systems are electrically connected to selected ones of the power generation sources. A system level combiner is in each of the energy storage systems, and the system level combiner combines power from the energy storage devices and selected ones of the power generation sources to provide system level combined power as a first output. A reservoir level combiner combines the system level combined power from a plurality of system level combiners into a reservoir level combined power. A power conditioning system receives, combines, and conditions the reservoir level combined power from the energy storage systems for supply to a power network. The energy storage devices are electrically connected to each other through the system level combiner and the reservoir level combiner.

Abstract: The present disclosure is directed to a system and method for controlling an energy storage system. The energy storage system includes a plurality of parallel-connected energy storage devices. The method includes determining, by one or more controllers, a limiting energy storage device based at least in part on a current rating for the limiting energy storage device. The method includes determining, by the one or more controllers, an adjusted allowable system current based at least in part on modifying one or more operational parameters of the limiting energy storage device. The method includes determining, by the one or more controllers, a modified operational parameter of the limiting energy storage device to increase the allowable system current of the energy storage system. The method includes controlling the limiting energy storage device based at least in part on the modified operational parameter.

Abstract: The present disclosure is directed to an energy storage device having improved thermal performance. More specifically, the energy storage device includes a housing with side walls that define an internal volume. The side walls include bottom and front side walls, with the front side wall having an air inlet and outlet configured to circulate cooling air therethrough. The energy storage device also includes a plurality of cells arranged in a matrix within the internal volume atop the bottom side wall. Further, the cells define a top surface. Further, the energy storage device includes an exhaust manifold adjacent to the front side wall between at least a portion of the cells and the air inlet. Thus, the exhaust manifold is configured to direct airflow from the top surface towards the bottom side wall and then to the air outlet so as to provide an airflow barrier between cooling air entering the air inlet and the cells.

Abstract: Systems and methods for controlling power distribution are provided. The method includes receiving a power command, wherein the power command requests a discharge from one or more BESS units, and wherein the one or more BESS units are housed in one or more temperature controlled rooms. For each of the one or more temperature controlled rooms, a lowest energy remaining of the one or more BESS units in the temperature controlled room is determined; a low threshold is determined based on the determined lowest energy remaining and a floor; a limit is determined based on the determined low threshold; and the limit is assigned to each of the one or more BESS units housed in the temperature controlled room. The method includes causing the power command to be at least partially satisfied by the one or more BESS units based on the assigned limits.

Abstract: Systems and methods for controlling the temperature of an energy storage system are provided. More specifically, a time period of increased battery temperature attributable to, for instance, charging or discharging of the battery can be identified. A control system can be used to reduce the ambient temperature of a space associated with the battery energy storage devices in the time period prior to or immediately before the period of increased battery temperature. The ambient temperature can be maintained at a nominal ambient temperature at other times.

Abstract: Systems and methods for controlling performance parameters for an energy storage device include providing primary control signals to an energy storage device that indicate at least one operating value in a range defined by at least one set point value for one or more performance parameters of the energy storage device. In one embodiment, an actual performance score for the energy storage device operated in accordance with the primary control signals is determined and compared with a required performance score to determine a performance score evaluation parameter. Additional control signals are then determined and provided to the energy storage device in a manner that adjusts the at least one operating value of the one or more primary control signals relative to the at least one set point value for the one or more performance parameters based at least in part on the performance score evaluation parameter.

Abstract: The present disclosure is directed to systems and methods for providing a cooling airflow to an energy storage system. The energy storage system can include one or more energy storage devices positioned within a defined thermal zone. The energy storage system can include a thermal control system configured to provide a cooling airflow to the one or more energy storage devices. The thermal control system can include a heat exchanging device configured to provide a cooled airflow to the defined thermal zone. The thermal control system can also include a moveable element configured to adjust a distribution of airflow within the defined thermal zone.

Abstract: The present disclosure is directed to a system and method for controlling an energy storage system. The energy storage system includes a plurality of parallel-connected energy storage devices. The method includes determining, by one or more controllers, a limiting energy storage device based at least in part on a current rating for the limiting energy storage device. The method includes determining, by the one or more controllers, an adjusted allowable system current based at least in part on modifying one or more operational parameters of the limiting energy storage device. The method includes determining, by the one or more controllers, a modified operational parameter of the limiting energy storage device to increase the allowable system current of the energy storage system. The method includes controlling the limiting energy storage device based at least in part on the modified operational parameter.

Abstract: Systems and methods for controlling performance parameters for an energy storage device include providing primary control signals to an energy storage device that indicate at least one operating value in a range defined by at least one set point value for one or more performance parameters of the energy storage device. In one embodiment, an actual performance score for the energy storage device operated in accordance with the primary control signals is determined and compared with a required performance score to determine a performance score evaluation parameter. Additional control signals are then determined and provided to the energy storage device in a manner that adjusts the at least one operating value of the one or more primary control signals relative to the at least one set point value for the one or more performance parameters based at least in part on the performance score evaluation parameter.