Abstract: This disclosure provides an energy storage apparatus, an energy storage apparatus control method, and a photovoltaic system. The energy storage apparatus includes: a plurality of battery clusters, a plurality of conversion units, a start unit, and a controller. The controller includes a plurality of control units. The start unit is configured to: after receiving a start signal, control a control switch in at least one battery cluster to close, to start a control unit corresponding to the battery cluster. The control unit is configured to: determine, based on a state of the control switch in the battery cluster, whether a black start mode is on; and when determining that the black start mode is on, control a DC-DC converter in the corresponding conversion unit to release electric energy stored in a battery pack in the corresponding battery cluster, to energize a direct current bus.

Abstract: An energy storage apparatus, including a plurality of battery modules, a switch unit, a start unit; and an electrical energy output port. The energy storage apparatus is configured for use in a photovoltaic power generation system having a plurality of photovoltaic modules, a direct current-to-direct current (DC/DC) converter, and a direct current-to-alternating current (DC/AC) converter. The plurality of battery modules is separately connected to the start unit and the switch unit, and the plurality of battery modules are configured to, when the start unit receives a start signal, control the switch unit to be turned on. The energy storage apparatus is configured to, in response to the switch unit being turned on, output electrical energy of the plurality of battery modules through the electrical energy output port, and, in response to the switch unit being turned off, disconnect the plurality of battery modules from the electrical energy output port.

Abstract: An energy storage system includes at least one battery cluster, at least two direct current DC/DC conversion modules, and a control unit. An output end of each battery cluster is connected to an input end of each DC/DC conversion module with a switch, and output ends of the at least two DC/DC conversion modules are connected in parallel to a direct current bus. The control unit is connected to each battery cluster and each DC/DC conversion module with a control bus, to control charging and discharging of each battery cluster and control each DC/DC conversion module to perform direct current conversion. The control unit is further configured to control turn-on or turn-off of a switch used by each battery cluster to connect to each DC/DC conversion module, so as to control connections between each battery cluster and different quantities of DC/DC conversion modules.

Abstract: A method for controlling an energy storage system includes: determining that a first battery cluster in a plurality of battery clusters needs to be calibrated; and controlling, based on a state of charge SOC of the first battery cluster and a current charging or discharging state of the energy storage system, the first battery cluster to be charged or discharged or to be in a standby state, so that the first battery cluster satisfies a SOC calibration condition. In the method, charging, discharging, or standby-state control needs to be performed on only one battery cluster that needs to be calibrated in the energy storage system, independent decoupling management is implemented on the battery cluster, and normal running of the energy storage system is not affected. This enables the battery cluster to quickly satisfy the SOC calibration condition and can improve SOC accuracy of the energy storage system.

Abstract: This application describes an energy storage system including an energy storage module, a direct current bus, a power conversion module, a first power supply module, a second power supply module, and a battery management system. In some implementations, the first power supply module is configured to: select a larger voltage between an output direct current voltage of the energy storage module and a bus voltage of the direct current bus as an input voltage, and output a first direct current voltage. The first power conversion module is configured to: convert the alternating current mains or an output alternating current voltage of the power conversion module into a second direct current voltage. The second power supply module is configured to: select a larger voltage between the first direct current voltage and the second direct current voltage as a target voltage, and supply power to the battery management system based on the target voltage.

Abstract: A photovoltaic energy system and a method for detecting a ground insulation impedance, improve accuracy of detecting a ground insulation impedance after one or more conversion circuits are connected in parallel. The photovoltaic energy system includes one or more conversion circuits and a detection circuit. The detection circuit includes an alternating current signal source and a sampling resistor that are connected in series, a first sampling circuit, and a control circuit. The control circuit is configured to control the alternating current signal source to output harmonic signals of a first frequency and a second frequency. The first sampling circuit is configured to: when the alternating current signal source outputs the harmonic signal of the first frequency, collect a voltage at both terminals of the sampling resistor to obtain a first voltage.

Abstract: The energy storage container includes a container controller, a plurality of battery clusters, and a plurality of air conditioners. The plurality of air conditioners is evenly distributed in at least one of a door or a side wall of the energy storage container. Each battery cluster includes a plurality of battery modules connected in series. Each battery cluster has a corresponding air conditioner. The container controller jointly controls the plurality of air conditioners to adjust internal temperature of the energy storage container. The air conditioners in the energy storage container are disposed in an evenly distributed manner rather than a conventional centralized manner. In addition, the air conditioners are disposed in a correspondence with the battery clusters, so that the battery clusters can be effectively cooled. This ensures consistency between capacities of the battery clusters as far as possible, ensures operation safety of the battery clusters.

Abstract: An energy storage system includes a fire suppression system controller, a fire extinguishing apparatus, a first sensing unit configured to detect a temperature and smoke of the energy storage system, a second sensing unit configured to detect a thermal runaway parameter, an energy storage system controller, and an energy storage unit. When the thermal runaway parameter output by the second sensing unit meets a thermal runaway condition, the energy storage system controller sends alarm information to the fire suppression system controller, to stop energy charging or energy supply of the energy storage unit. When receiving the alarm information sent by the first sensing unit and/or the energy storage system controller, the fire suppression system controller indicates the fire extinguishing apparatus to perform a fire extinguishing operation.

Abstract: An energy storage system and a method for controlling an the energy storage system, includes a plurality of energy storage units. The energy storage unit includes a plurality of battery cells, a plurality of balancing units, a voltage conversion unit, a first switch, a second switch, and a control unit. The control unit is configured to detect fault cases of the plurality of battery cells, and control open and closed states of the first switch and the second switch. According to the application, it can be ensured that each energy storage unit in the energy storage system can continuously work when a battery cell is faulty and when state of charge balance between battery cells is implemented, thereby greatly improving reliability of the energy storage system with low costs.

Abstract: A photovoltaic energy system and a method for detecting a ground insulation impedance, improve accuracy of detecting a ground insulation impedance after one or more conversion circuits are connected in parallel. The photovoltaic energy system includes one or more conversion circuits and a detection circuit. The detection circuit includes an alternating current signal source and a sampling resistor that are connected in series, a first sampling circuit, and a control circuit. The control circuit is configured to control the alternating current signal source to output harmonic signals of a first frequency and a second frequency. The first sampling circuit is configured to: when the alternating current signal source outputs the harmonic signal of the first frequency, collect a voltage at both terminals of the sampling resistor to obtain a first voltage.

Abstract: A battery management system is provided in this application, which includes a monitoring module and a sampling module. The sampling module performs sampling on an operating parameter of a direct current converter to obtain target sampling information, and sends the target sampling information to the monitoring module. The monitoring module receives the target sampling information sent by the sampling module, and sends the target sampling information to a central monitoring unit, so that the central monitoring unit determines target charge power for charging an energy storage battery by a power conversion system PCS; and receives a first control instruction sent by the central monitoring unit, and controls the direct current converter to adjust charge power for charging the energy storage battery by the power conversion system PCS to the target charge power.