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: Embodiments of this application provide a photovoltaic power conversion apparatus. The photovoltaic power conversion apparatus includes a first housing, a power component, at least one second housing, and at least one wiring terminal. The first housing forms a first accommodation cavity, and the power component is fixedly disposed in the first accommodation cavity. The at least one of the second housing forms a second accommodation cavity, and the at least one second housing is disposed outside a connection area of a first side wall of the first housing by using an installation wall. The wiring terminal sealingly penetrates through a part of the connection area of the first side wall, a first end of the wiring terminal is located in the first accommodation cavity, and a second end of the wiring terminal is located in the second accommodation cavity.

Abstract: Embodiments of this application disclose a photovoltaic system, to resolve a problem of high costs per kilowatt hour of a photovoltaic system. The photovoltaic system includes a first photovoltaic array, a first power converter, a second photovoltaic array, a second power converter, an energy storage converter, a storage battery, and a photovoltaic inverter. The first photovoltaic array is connected to the photovoltaic inverter through the first power converter. The second photovoltaic array is directly connected to the energy storage converter, or at least one part of the second photovoltaic array is connected to the energy storage converter through the second power converter. The energy storage converter is connected to the photovoltaic inverter and the storage battery. The photovoltaic inverter is connected to a power grid.

Abstract: A photovoltaic system, an optimizer, a controller, a computer program product, a computer-readable storage medium, a chip, and a method for adjusting a working state of an optimizer are provided. The photovoltaic system includes a photovoltaic panel and an optimizer. The optimizer includes a controller, a first output port, and a second output port. The controller is configured to detect an electrical signal parameter between the first output port and the second output port. The controller is configured to adjust a working state of the optimizer from a no-output state or a limited-output state to an unlimited-output state when the electrical signal parameter changes. In the photovoltaic system, the working state can be adjusted without using an unlocking apparatus, so that an implementation is simple, and costs are reduced.

Abstract: A pre-charging circuit is provided, including a first switch, a second switch, a diode, a first current-limiting apparatus, a capacitor, and an inverter unit. One end of the pre-charging circuit is connected to a power grid. After the first current-limiting apparatus, the first switch, and the diode are connected in series, one end of a line formed by the series connection is connected to one terminal of the capacitor, the other end of the line is connected to a first-phase alternating current of the power grid, and the other terminal of the capacitor is connected to a second-phase alternating current of the power grid via the inverter unit and the second switch successively.

Abstract: An inverter in a power generation system converts a direct current that is input from a direct-current-side device into an alternating current for power supply. The inverter includes a control apparatus and a communications apparatus. The control apparatus controls the inverter to convert the direct current that is input from the direct-current-side device into an alternating current for power supply. The communications apparatus is coupled to the control apparatus, and sends a networking information request signal used to request networking information to the direct-current-side device in the power generation system through a direct-current power line, where a frequency of the networking information request signal is within a first frequency band. The communications apparatus also receives the networking information from the direct-current-side device; and sends a control signal to the direct-current-side device, where a frequency of the control signal is within a second frequency band.

Abstract: A photovoltaic control apparatus and method, and a system, and relates to the field of photovoltaic power generation technologies, to reduce the system costs. The apparatus is applied to a photovoltaic system including a plurality of strings. The apparatus includes a control circuit, a first path circuit, a second path circuit, and an inverter circuit. The control circuit is configured to control a direct current signal of at least one first string in the plurality of strings to be transmitted by using the first path circuit. The first path circuit is configured to perform MPPT processing on the direct current signal of the first string. The control circuit is further configured to control a direct current signal of at least one second string in the plurality of strings to be transmitted by using the second path circuit.

Abstract: A photovoltaic system includes a plurality of photovoltaic racks, a plurality of photovoltaic strings connected to each photovoltaic rack in the plurality of photovoltaic racks, a detector, and a controller. Each photovoltaic rack is configured to rotate by an angle through the controller. Each photovoltaic string is configured to convert light energy into electric energy. The detector is separately connected to the controller and the plurality of photovoltaic strings, and is configured to detect blocking parameters of the plurality of photovoltaic strings. The controller is connected to the plurality of photovoltaic racks, and is configured to: control, based on illumination angles, the plurality of photovoltaic racks to rotate by an angle, obtain a photovoltaic rack blocking relationship based on the blocking parameters of the plurality of photovoltaic strings, and adjust a rotation angle of a first photovoltaic rack or a second photovoltaic rack based on the photovoltaic rack blocking relationship.

Abstract: An energy storage system includes one or more energy storage unit clusters, and the energy storage unit cluster includes at least two energy storage modules connected in series. The energy storage system further includes a first bus, a second bus, and a centralized monitoring system of the energy storage unit cluster, where the second bus is a direct current bus. The energy storage unit cluster is coupled to the first bus by using a first converter. One energy storage module includes one energy storage element group and one DC/DC converter, and the energy storage element group is coupled to the second bus by using the DC/DC converter. The centralized monitoring system is connected to the energy storage unit cluster through a control bus, and is configured to control a DC/DC converter in any energy storage module in the energy storage unit cluster.

Abstract: A power system is disclosed. Output terminals of a power supply or a DC-to-DC unit are cascaded to increase an output voltage, so as to reduce a current between the power supply or the DC-to-DC unit and the DC-to-AC unit, and resolve cost and loss problems of the cable from the power supply or the DC-to-DC unit to the DC-to-AC unit. In addition, according to the power system provided in the embodiments of this application, a quantity of cables from the power supply or the DC-to-DC unit to the DC-to-AC unit may be further reduced by cascading output terminals of the power supply or the DC-to-DC unit and cascading inputs of the DC-to-AC unit, thereby reducing system costs. In addition, in the power system provided in the embodiments of this application, cascaded input and isolated output of the DC-to-AC unit can reduce a specification of a power conversion device.

Abstract: This application discloses a method and an apparatus for detecting a solar cell of a photovoltaic plant. The method includes: obtaining a first infrared image and a second infrared image, where the first infrared image includes infrared image information corresponding to an ambient infrared signal reflected by a to-be-detected solar cell operating in a short-circuit state, the second infrared image includes infrared image information corresponding to an infrared signal emitted by the to-be-detected solar cell operating in a first state and infrared image information corresponding to an ambient infrared signal reflected by the to-be-detected solar cell, and the first state is another state other than the short-circuit state; and detecting, based on the first infrared image and the second infrared image, whether the to-be-detected solar cell has a defect.

Abstract: A photovoltaic system includes a plurality of photovoltaic strings, at least one junction device, and at least one inverter. Each photovoltaic string includes a first direct current output terminal, and is configured to generate a first direct current. Each junction device is coupled to the plurality of photovoltaic strings. Each junction device is configured to output second direct currents through second direct current output terminals of the junction device after converging a plurality of first direct currents. An ith junction device includes a plurality of second direct current output terminals. The ith junction device is configured to output a plurality of mutually independent second direct currents after converging a plurality of first direct currents, and i is a positive integer. A quantity of the plurality of second direct currents is less than a quantity of the plurality of first direct currents.

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: 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: This application discloses an inverter of a grid-connected photovoltaic power generation system. The inverter includes a grid-connected inverter unit, an alternating current auxiliary power supply, and a startup apparatus. The alternating current auxiliary power supply is configured to convert an alternating current from an alternating current power grid into a direct current. An input terminal of the grid-connected inverter unit is connected to a bus capacitor. The startup apparatus is configured to: obtain an alternating current from the alternating current power grid, convert the alternating current into a direct current, and then provide the direct current to the bus capacitor, to start the grid-connected inverter unit. By using the inverter, the grid-connected photovoltaic power generation system can be started normally when there is insufficient or no sunlight, to allow scheduling of the grid-connected photovoltaic power generation system to be normally performed.

Abstract: Embodiments of this application disclose an arc detection method for performing protection in an energy storage system, and a related apparatus, to improve accuracy of arc detection in an energy storage system, promptly take an arc extinguishing measure, and reduce a probability of causing a safety hazard. The method in the embodiments of this application includes: A control apparatus obtains an electrical signal at an electrical connection point in an energy storage system. The control apparatus determines a frequency domain amplitude based on a frequency domain characteristic of the electrical signal. When the frequency domain amplitude is greater than a preset amplitude, the control apparatus controls the energy storage system to perform an arc extinguishing and protection operation on the electrical connection point.

Abstract: The present invention 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: Voltage in the photovoltaic power generation system can be increased under a same power conversion condition, to reduce a current in the photovoltaic power generation system, thereby reducing energy consumption and reducing costs of the photovoltaic power generation system. The system includes: a photovoltaic array, a direct current conversion unit, a bus unit, and an inverter unit, where there are one or more photovoltaic arrays; the photovoltaic array is configured to: convert solar energy into electric energy, in other words, generate direct current power, and output a direct current voltage. The bus unit stores direct current electric energy output by the direct current conversion unit or directly stores the direct current electric energy output by the photovoltaic array, to increase a bus voltage in the first bus unit.

Abstract: A fault detection apparatus includes an image capture module and a detection module, and the fault detection apparatus is configured to capturing an image of the photovoltaic module in a light emitting state, and performing fault detection on the photovoltaic module based on the image when a signal-to-noise ratio of the image is maximized, to identify a fault type of the photovoltaic module.

Abstract: A related power conversion circuit includes a three-level switch circuit and a resonant circuit, and a control method of the related power conversion circuit includes: controlling all transistors in the three-level switch circuit to be turned off, where a body diode connected in parallel to a transistor S1, a body diode connected in parallel to a transistor Q1, and a body diode connected in parallel to a transistor Q2 are all turned on based on a current freewheeling function of the resonant circuit; controlling the S1 to be turned on, to set up a first working state of the power conversion circuit; and after the first working state lasts for a time length T1, controlling the Q1 and the Q2 to be turned on.