Abstract: A data processing system in the power station operation and maintenance system may determine a faulty module and a normal module based on module data of each photovoltaic module in a photovoltaic string, and obtain first power generation data of the faulty module and second power generation data of the normal module. Further, the data processing system may determine an annual lost energy yield of the faulty module based on the first power generation data, the second power generation data, and a preset energy yield of the photovoltaic power station, and obtain a target operation and maintenance measure from a plurality of operation and maintenance measures based on the annual lost energy yield. In this case, a communication system in the power station operation and maintenance system may notify an operation and maintenance user of the photovoltaic power station to perform operation and maintenance on the faulty module.

Abstract: The present disclosure discloses an energy storage converter, wherein a first end of the energy storage converter is coupled to at least one of the Q cell strings, and second end of the energy storage converter is configured to connect to a power grid. The first energy storage converter includes a DC/AC conversion unit and at least one DC/DC conversion unit. The DC/DC conversion unit is configured to perform adaptation between a voltage of the DC/AC conversion unit and a voltage of a cell string. Therefore, a cell capacity is fully used, and a waste of the cell capacity is reduced.

Abstract: A photovoltaic power generation system includes a single-stage inverter, an anti-backflow circuit, a photovoltaic string, and a coupling capacitor. The anti-backflow circuit is connected to one input end of the single-stage inverter, one output end of the photovoltaic string is connected to the other input end of the single-stage inverter, and the other output end of the photovoltaic string is connected to the anti-backflow circuit. The photovoltaic string includes a buck optimizer and a photovoltaic panel. The anti-backflow circuit is configured to prevent a backflow current from flowing back to the photovoltaic string. The coupling capacitor is connected in parallel to two ends of the anti-backflow circuit and is configured to transmit a signal between each buck optimizer in the photovoltaic string and the single-stage inverter, to control backflow of the backflow current when the anti-backflow circuit fails.

Abstract: A protection apparatus includes an interface, a protection switch, a direct current bus, and a controller. The apparatus is connected to at least two photovoltaic units via the interface, the at least two photovoltaic units are coupled to the direct current bus inside the apparatus to form at least two branches, and each branch is connected to at least one photovoltaic unit. The protection switch is configured to disconnect all or some of the photovoltaic units from the direct current bus, to enable a maximum of three photovoltaic units to be directly connected in parallel. According to the apparatus, a photovoltaic unit and a line are protected with a low power loss when a photovoltaic power generation system is faulty.

Abstract: The present disclosure relates to the technical field of pyrolysis and improvement of caking middling coals, in particular to a low temperature pyrolysis method of a caking middling coal. The present disclosure provides a low temperature pyrolysis method of a caking middling coal, including the following steps: conveying the caking middling coal into a pyrolysis reactor through a top of the pyrolysis reactor; dividing a reaction chamber of the pyrolysis reactor into a drying section, a softening section, a melting and depolymerization section, a solidification section, and a cooling section by means of multi-channel gas distribution; and conducting zoned temperature control-based pyrolysis to obtain semi-coke at a bottom of the reactor as well as tar and coal gas at the top of the reactor. The pyrolysis method can well avoid caking and swelling of the caking middling coal during pyrolysis.

Abstract: A photovoltaic power generation system and a conversion circuit. Two groups of photovoltaic arrays are cascaded by using the conversion circuit disposed in the photovoltaic power generation system to effectively increase an input voltage of a DC/AC conversion circuit. In this way, a cable with an existing diameter specification can improve current transmission in the photovoltaic power generation system, to effectively reduce costs of the photovoltaic power generation system. A voltage to earth at an intermediate node in the conversion circuit is adjusted to a first preset value, so that both an absolute value of a voltage to earth of a first group of photovoltaic arrays and an absolute value of a voltage to earth of a second group of photovoltaic arrays are less than a first threshold.

Abstract: The present disclosure discloses an energy storage system. The energy storage system includes M cell strings, N energy storage converters, first ends of the N energy storage converters are coupled to at least one of the M cell strings, and second ends of the N energy storage converters are configured to connect to a power grid. A first end of a first energy storage converter is coupled to Q cell strings in the M cell strings, and the first energy storage converter includes a DC/AC conversion unit and at least one DC/DC conversion unit. A first DC/DC conversion unit is coupled to at least one of the Q cell strings by using the first end of the first energy storage converter, the first DC/DC conversion unit is coupled to the DC/AC conversion unit, and the DC/AC conversion unit is coupled to the power grid by using a second end of the first energy storage converter. The first DC/DC conversion unit is configured to perform adaptation between a voltage of the DC/AC conversion unit and a voltage of a cell string.

Abstract: A protection apparatus includes an interface, a protection switch, a direct current bus, and a controller. The apparatus is connected to at least two photovoltaic units via the interface, the at least two photovoltaic units are coupled to the direct current bus inside the apparatus to form at least two branches, and each branch is connected to at least one photovoltaic unit. The protection switch is configured to disconnect all or some of the photovoltaic units from the direct current bus, to enable a maximum of three photovoltaic units to be directly connected in parallel. According to the apparatus, a photovoltaic unit and a line are protected with a low power loss when a photovoltaic power generation system is faulty.

Abstract: Embodiments of this application provide an energy storage system and a black start method. The energy storage system includes a black start controller, a battery module, a first converter, and a system control unit. The black start controller outputs a black start signal, the battery module generates an output voltage based on the black start signal, and the first converter supplies power to the system control unit based on the black start signal and the output voltage of the battery module, to enable the system control unit to implement black start of the energy storage system based on the black start signal.

Abstract: An energy storage system includes a battery cluster, a direct current converter, a controller, and at least one power conversion system. The energy storage system includes at least one direct current branch. The direct current branch includes a battery cluster and a direct current converter that are connected to each other. The direct current converter performs direct current conversion on a direct current provided by the battery cluster. Each battery cluster includes at least two energy storage modules that are connected in series. The controller controls the first equalization circuit, to balance electricity quantities of battery modules in the battery cluster, and allocates operating power to the power conversion system and the direct current converter. In this solution, impact of bucket effect on the energy storage system is reduced, so that a battery capacity can be more fully utilized.

Abstract: This application discloses a method for implementing a fast power response and a power plant. The method is applied to a power plant-end power control apparatus, and includes determining a whole-plant reactive power target value and/or a whole-plant active power target value of the power plant. The method also includes determining, based on the whole-plant reactive power target value and/or the whole-plant active power target value, a second power control instruction readable to each photovoltaic inverter or power conversion system in the power plant.

Abstract: This application provides a charging module and a charging system. The charging system includes a charging module. The charging module includes a direct current-to-direct current (DC/DC) charging component, a functional interface, an inverter, and a control and guide component. The functional interface includes a photovoltaic interface. The DC/DC charging component is configured to receive a first power exported by a photovoltaic module to charge an electric vehicle (EV). In this way, after receiving, through the photovoltaic interface, electrical energy converted from solar energy, the charging module does not need to cooperate with an on-board charger (OBC), but uses the DC/DC charging component to charge the EV with a direct current. The charging module provided in this application is not limited by a charging power of the OBC when charging the EV, thereby increasing an actual power for charging the EV and a charging speed.

Abstract: Embodiments of this application provide an inverter apparatus and an inverter system. In the inverter apparatus, a direct current output end of an alternating and direct current distribution cabinet is connected to a first direct current input end of an inverter. A first alternating current output end of the inverter is connected to an alternating current input end of the alternating and direct current distribution cabinet, and the alternating and direct current distribution cabinet outputs a converged alternating current. In this way, on-site wiring is simplified, and on-site maintenance is reduced to some extent.

Abstract: A power converter box and at least one junction box are integrated on a backplane of the photovoltaic module as a whole, and there is a cable for connecting the power converter and the junction box. In this case, relative to the conventional technology in which a junction box is independent of a power converter, a length of a cable used when the junction box and the power converter box are taken as a whole is shorter than a length of a cable used in the conventional technology. In this case, compared with the conventional technology in which a cable is connected to an independently placed power converter, the power converter only needs to establish a connection relationship by using a solder ribbon, a circuit board cable, and the like with low costs, so that production costs are low.

Abstract: A first input end of a first inverter is connected to a second end of a direct current positive bus, and a second input end of the first inverter is connected to a second end of a neutral bus. A first input end of a second inverter is connected to the second end of the neutral bus, and a second input end of the second inverter is connected to a second end of a direct current negative bus. A controller is configured to control, in startup and shutdown processes, a voltage to ground of the direct current positive bus, a voltage to ground of the direct current negative bus, and a voltage to ground of the neutral bus each to be less than or equal to a preset voltage threshold, to ensure personal safety and device safety.

Abstract: In a detection condition determining method, a control center obtains a working parameter value of a target photovoltaic device in a first time length closest to a current time point, where the working parameter value of the target photovoltaic device may be provided for the control center by a photovoltaic inverter coupled to the target photovoltaic device. The control center detects the target photovoltaic device in response to the control center determining, based on the working parameter value, that an environmental parameter value of the target photovoltaic device meets an environmental parameter threshold. Using the method helps reduce operation and maintenance costs of a photovoltaic power station.

Abstract: An example system includes an inverter and at least one combiner box. The combiner box includes a plurality of direct current-direct current (DC-DC) circuits and one controller. The controller is configured to: when an output voltage of the combiner box is greater than or equal to a first preset voltage and less than or equal to a second preset voltage, control the combiner box to output a maximum power. When the output voltage of the combiner box is greater than the second preset voltage, the controller controls an output power of the combiner box to decrease as the output voltage increases. The second preset voltage is greater than the first preset voltage, and the maximum power is a sum of maximum powers of all photovoltaic strings connected to the combiner box.

Abstract: A photovoltaic system includes a controller and two groups of inverters. The two groups of inverters include a positive inverter group and a negative inverter group. The positive inverter group includes at least two inverters: a first inverter and a third inverter. The negative inverter group includes at least two inverters: a second inverter and a fourth inverter. Alternating current output ends of the first inverter and the third inverter are connected in parallel. Direct current input ends of the first inverter and the second inverter are connected in series. Alternating current output ends of the second inverter and the fourth inverter are connected in parallel. Direct current input ends of the third inverter and the fourth inverter are connected in series.

Abstract: A direct current power supply system includes N power supply devices, N triple-pole direct current switches, a positive bus, an M bus, and a negative bus. A positive input terminal of an ith triple-pole direct current switch is coupled to a first output terminal of an ith power supply device, an M input terminal of the ith triple-pole direct current switch is coupled to a second output terminal of the ith power supply device, a negative input terminal of the ith triple-pole direct current switch is coupled to a third output terminal of the ith power supply device, a positive output terminal of the ith triple-pole direct current switch is coupled to the positive bus, an M input terminal of the ith triple-pole direct current switch is coupled to the M bus, and a negative output terminal of the ith triple-pole direct current switch is coupled to the negative bus.

Abstract: A method and apparatus for suppressing cross current including: obtaining a common-mode current and a common-mode injection voltage of each inverter in an inverter parallel system; determining a virtual damping voltage of each inverter based on the common-mode current of each inverter and a preset common-mode damping factor, where if a direction in which a current flows out of the inverter is a positive direction, the preset common-mode damping factor is a negative value, or if a direction in which a current flows into the inverter is a positive direction, the preset common-mode damping factor is a positive value; superimposing the virtual damping voltage on the common-mode injection voltage of each inverter, to obtain a target common-mode voltage of each inverter; and controlling operation of each inverter based on the target common-mode voltage of each inverter and a differential mode voltage of each inverter.