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.

Abstract: A photovoltaic system and a circulating current suppression method. The system includes a controller and at least two inverters. A direct current input terminal of each inverter is connected to a corresponding photovoltaic array. Alternating current output terminals of the at least two inverters are connected in parallel. The controller is configured to: obtain a direct current component of a common-mode output current of at least one of the at least two inverters and adjust a direct current bus voltage of the corresponding inverter based on a magnitude of the direct current component of the common-mode output current, to suppress a circulating current between the at least two inverters. A circulating current between a plurality of inverters connected in parallel can be suppressed, thereby reducing loss caused by a circulating current, and improving power supply efficiency.

Abstract: A power supply system including three output ends of a power converter respectively connected to a first end of a positive/negative direct current bus and a first end of a neutral bus; two input ends of a first inverter respectively connected to a second end of the positive direct current bus and a second end of the neutral bus; two input ends of a second inverter respectively connected to a second end of the neutral bus and a second end of the negative direct current bus; a controller outputs an overvoltage alarm signal when at least one of the following conditions is met: a to-ground voltage of the positive/ negative direct current bus or a to-ground voltage of the neutral bus is greater than or equal to the preset threshold.

Abstract: A power station inspection system and a power station inspection method are disclosed. A power station inspection system includes an unmanned aerial vehicle, and an unmanned aerial vehicle flight controller, a central controller, and at least two types of data collection terminals that are disposed on the unmanned aerial vehicle. The central controller is configured to control the unmanned aerial vehicle flight controller, so that the unmanned aerial vehicle flight controller controls flight of the unmanned aerial vehicle. The central controller is further configured to control the at least two types of data collection terminals to collect at least two types of component image data of a power station component in a flight process of the unmanned aerial vehicle.

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: A method and an apparatus (400) for performing fault detection, are provided includes: controlling, by a power station management system in a preset photovoltaic module order by using an inverter connected to a current to-be-detected photovoltaic module, the current to-be-detected photovoltaic module to be in a target status, and when determining that the current to-be-detected photovoltaic module is in the target status, controlling a mobile image capturing terminal to collect image data of the current to-be-detected photovoltaic module (S201), where the image data is used to detect a fault status of the current to-be-detected photovoltaic module; and when determining that the mobile image capturing terminal obtains the image data of the current to-be-detected photovoltaic module through collection, continuing, by the power station management system, to control, in the preset photovoltaic module order by using an inverter connected to a next to-be-detected photovoltaic module.

Abstract: A combiner box includes a switching device, a sampling circuit, and a controller. The switching device is connected in parallel between a positive input port and a negative input port. The sampling circuit is configured to collect at least one of an input parameter and an output parameter of the combiner box. The controller is configured to control the switching device to be closed when determining, based on the at least one parameter, that a short circuit occurs between a positive output cable and a negative output cable or a positive output cable and a negative output cable are reversely connected, so that the switching device, the positive input port, and the negative input port form a closed loop.

Abstract: An image/video capture apparatus is provided, to capture image data of a photovoltaic panel (101) and surroundings, and a controller (502) recognizes a category corresponding to the image data, and generates different instructions to control rotation of a photovoltaic tracker (102), to remove dust or snow accumulating on the photovoltaic panel (101). This does not need continuous heating, but is simple and efficient, saves electric energy, and resolves a technical problem that a conventional snow removal method of heating has low efficiency and wastes electric energy. In addition, a corresponding controller (1200) is further provided.

Abstract: An inverter includes a direct-current conversion unit, a busbar unit, and an inversion unit. The direct-current conversion unit includes a first positive input terminal, a first negative input terminal, a second positive input terminal, a second negative input terminal, a first direct current DC-to-DC module, a second DC-to-DC module, a first on/off control device, a second on/off control device, a first switch, and a second switch. The first positive input terminal and the first negative input terminal are configured to connect a first photovoltaic string, the second positive input terminal and the second negative input terminal are configured to connect a second photovoltaic string, and a connection relationship of a circuit in the direct-current conversion unit can be changed based on combinations of turning-on or turning-off of the first switch and the second switch.

Abstract: This application relates to the field of power technologies, and provides a photovoltaic system, which can increase a working voltage of a photovoltaic string. The photovoltaic system includes an adapter circuit, a first photovoltaic string, a second photovoltaic string, and a controller. The controller includes an inverter or a combiner box. The first photovoltaic string and the second photovoltaic string are configured to provide electric energy for the controller. The adapter circuit is configured to be connected to the first photovoltaic string in series, and further configured to connect the second photovoltaic string to the first photovoltaic string in series when a voltage of the first photovoltaic string is lower than a preset threshold.

Abstract: This application discloses a protection circuit for preventing a misconnection at an input end and a photovoltaic power generation system, and relates to the field of power electronics technologies. The protection circuit includes an input end, a misconnection detection unit, a mechanical interlocking unit, and a switch unit. The input end is configured to connect to an output end of a direct current power supply. A first input end of the misconnection detection unit is connected to a first port of the input end, and a second input end of the misconnection detection unit is connected to a second port of the input end. An output end of the misconnection detection unit is coupled to the mechanical interlocking unit. The mechanical interlocking unit is connected to the switch unit. A first end of the switch unit is configured to connect to the input end, and a second end of the switch unit is configured to connect to a next circuit.

Abstract: Embodiments of this application provide a power system. An output terminal of a power supply or a DC-to-DC unit is cascaded. In addition, according to the power system provided in 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 an output terminal of the power supply or the DC-to-DC unit and cascading an input of the DC-to-AC unit.

Abstract: This application discloses a photovoltaic direct-current breaking apparatus, including a positive connection terminal and a negative connection terminal for connecting a photovoltaic string and a photovoltaic energy converter, a first diode, a first switch, a convector circuit, and an energy absorption circuit, where the first switch, the convector circuit, and the energy absorption circuit are connected in parallel. The convector circuit can effectively avoid arc discharge and ablation generated when the first switch cuts off a direct-current circuit between the photovoltaic string and the photovoltaic energy converter. The first diode can effectively bypass energy stored by an energy storage device in the photovoltaic energy converter, helping reduce required specifications of a semiconductor device in the convector circuit. The energy absorption circuit can also effectively reduce required specifications of the semiconductor device and a varistor.

Abstract: A linkage protection system includes an inverter, an anti-potential-induced degradation (PID) apparatus, and an insulation-monitoring apparatus. The anti-PID apparatus is configured to inject a voltage into an input end or an output end of the inverter, to increase or decrease a voltage-to-earth of a photovoltaic system. The insulation-monitoring apparatus is configured to inject an insulation-monitoring voltage into a direct current (DC) side or an alternating current (AC) side of the inverter. The anti-PID apparatus and the insulation-monitoring apparatus directly or indirectly communicate with each other, to learn of information about whether a peer apparatus is operating, and perform linkage control. The anti-PID apparatus and the insulation-monitoring apparatus operate in different time periods.

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 photovoltaic power generation system includes a protection switch and a plurality of DC-DC converters. Each DC-DC converter includes a direct current bus, a DC-DC circuit, and at least one input interface. The input interface is configured to connect to a photovoltaic unit. The photovoltaic unit includes at least one photovoltaic module. The input interface is connected to the direct current bus by using the protection switch, the direct current bus is connected to an input end of the DC-DC circuit, and an output end of the DC-DC circuit is an output end of the DC-DC converter. The protection switch includes a release device and a switching device that are connected in series. The release device is configured to: when a short-circuit fault occurs on a line in which the release device is located, control the switching device to be disconnected.

Abstract: A photovoltaic string location update method and apparatus includes: obtaining, based on a physical map, a physical location of a first photovoltaic string corresponding to a first logical location in the physical map, the physical map indicating a correspondence between a logical location of a photovoltaic string and a physical location of the photovoltaic string, and the photovoltaic string includes the first photovoltaic string; and when the physical location of the first photovoltaic string in the physical map is different from a first actual physical location of the first photovoltaic string, updating the physical location of the photovoltaic string in the physical map to the first actual physical location, to obtain an updated physical map. The first actual physical location of the photovoltaic string is inconsistent with the physical location in the physical map, to prepare for subsequent operation and maintenance accurately performed on the photovoltaic string.

Abstract: Embodiments of this application disclose an inverter apparatus and an inverter apparatus control method. The inverter apparatus includes an inverter circuit and a control unit, and the control unit detects a driving mode of the inverter circuit based on a running state of the inverter circuit. When the inverter circuit outputs reactive power and an output current amplitude is greater than a current threshold, the control unit controls the inverter circuit in a full-bridge two-level bipolar control mode; and in other cases, the control unit controls the inverter circuit in a three-level control mode. This reduces a risk of breaking down horizontal bridge semiconductor switching devices by a voltage spike in an active turn-off process.

Abstract: A photovoltaic system includes the photovoltaic module, an electric energy conversion apparatus, an inverter, and a computing device. The computing device determines whether output power of the photovoltaic module meets a first preset condition, where the first preset condition is that the output power is greater than or equal to a first preset output power; when the first preset condition is met, the computing device determines to set the photovoltaic module to a default configuration direction, where the default configuration direction is a photovoltaic module orientation in which sunlight is irradiated onto the photovoltaic module with a minimum incident angle; and when the first preset condition is not met, the computing device determines to set the photovoltaic module to a target orientation, where the target orientation is different from the default configuration direction.

Abstract: An energy storage system, to improve operating efficiency and system reliability that exist when a component in the energy storage system is faulty, and avoid a waste of resources. The energy storage system includes a plurality of energy storage branches, at least one switch unit, and a control circuit. Each of the energy storage branches includes a first bus, a string-level converter, and a battery string that are sequentially connected in series, a plurality of balancing converters, and a shared bus. The battery string includes a plurality of battery units connected in series, and each of the battery units includes one battery pack. The battery pack is connected to an input side of one corresponding balancing converter, and output sides of the plurality of balancing converters are separately connected to the shared bus.