Abstract: A breaker apparatus and an inverter system are configured to disconnect an electrical connection when a fault occurs in a protected circuit. The breaker apparatus is connected in series in a protected circuit, and is configured to disconnect the electrical connection when a fault occurs in the protected circuit. The breaker apparatus includes a first branch, and a second branch. The first branch includes an overcurrent-automatic-disconnection unit and a first current limiting unit that are connected in series, where the overcurrent-automatic-disconnection unit is configured to be automatically disconnected when a current flowing through the overcurrent-automatic-disconnection unit exceeds a breaking current threshold. The a second branch is configured to be open or closed under control of the controller.

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: This application discloses a photovoltaic power generation system control method, a photovoltaic power generation system, and a switching apparatus, to reduce a loss of the photovoltaic power generation system. The switching apparatus includes: a switching unit, a detection unit, and a controller. The switching unit includes a first output end, a second output end, a first input end connected to each first DC/DC converter in a one-to-one correspondence, and a second input end connected to each second DC/DC converter in a one-to-one correspondence. The first output end is connected to an input end of a first DC/AC converter, and the second output end is connected to an input end of a second DC/AC converter. The detection unit is separately connected to the first DC/AC converter, the second DC/AC converter, a plurality of first DC/DC converters, and a plurality of second DC/DC converters.

Abstract: This application describes examples of a direct current combiner box, a photovoltaic power generation system, and a fault detection method. In one example, the direct current combiner box includes a fault detection unit, a protection circuit, and a boost circuit. The fault detection unit detects an operating parameter of the direct current combiner box. The protection circuit sends a protection signal to the boost circuit when the operating parameter meets a specified condition. The protection signal is used to enable the boost circuit to adjust a first voltage of a photovoltaic array at an input end of the direct current combiner box to a second voltage. After receiving the protection signal, the boost circuit adjusts the first voltage of the photovoltaic array at the input end of the direct current combiner box to the second voltage.

Abstract: A power sourcing equipment includes a residual current detection unit, a voltage detection unit, and a controller. The controller determines an insulation resistance value at the input end of the power sourcing equipment based on a first preset voltage parameter value, a first residual current value, a second preset voltage parameter value, and a second residual current value. The first residual current value is a residual current value of the power sourcing equipment when a voltage parameter of the power sourcing equipment includes the first preset voltage parameter value. The second residual current value is a residual current value of the power sourcing equipment when the voltage parameter of the power sourcing equipment includes the second preset voltage parameter value.

Abstract: A power supply system includes direct current combiner boxes and an inverter, where output terminals of all direct current combiner boxes are connected in series and/or in parallel and then coupled to an input terminal of the inverter, and the direct current combiner box includes a controller, a detection circuit, and a direct current conversion circuit. The direct current conversion circuit performs direct current conversion on an input terminal voltage of the direct current combiner box to obtain an output terminal voltage of the direct current combiner box. The detection circuit detects an output terminal parameter of the direct current combiner box, and sends the output terminal parameter of the direct current combiner box to the controller. The controller controls an output voltage of the direct current conversion circuit based on the output terminal parameter of the direct current combiner box.

Abstract: A photovoltaic system, a power supply system, and an insulation fault detection method. An insulation impedance detection circuit is connected between a bus and the ground. The bus includes the direct current positive bus, the neutral bus, or the direct current negative bus. The insulation impedance detection circuit includes at least a switch. The direct current negative bus is connected to the neutral bus by using an electrical element or a voltage source. A controller obtains insulation impedance based on voltages to ground of the bus that are separately corresponding to the switch before and after the switch is turned on, and determines, based on the insulation impedance, whether there is an insulation fault in the photovoltaic system, to perform protection in a timely manner.

Abstract: A photovoltaic system and a leakage current control method for the photovoltaic system includes at least one photovoltaic module group, at least one photovoltaic inverter, a grounded metal frame, and a sampling control unit. The photovoltaic module group is mounted on the grounded metal frame. An output end of the photovoltaic module group is connected to an input end of the photovoltaic inverter, and an output end of the photovoltaic inverter is connected to a power grid. The sampling control unit is coupled to both the photovoltaic module group and the photovoltaic inverter and is configured to detect a current value of a leakage current formed by a common-mode voltage of the photovoltaic inverter on a parasitic capacitor. Herein, the parasitic capacitor exists between the photovoltaic module group and the grounded metal frame.

Abstract: An impedance detection method and a photovoltaic system are provided to help reduce complexity and costs of impedance detection. The method includes: sampling a voltage between a direct current bus and a protective earthing at each of a first time point and a second time point, to obtain a first voltage value and a second voltage value; sampling a leakage current on the direct current bus at each of the first time point and the second time point, to obtain a first current value and a second current value; and calculating an insulation impedance value of a combiner box based on a difference between the first voltage value and the second voltage value and a difference between the first current value and the second current value, to determine whether impedance of the combiner box is abnormal.

Abstract: A direct current (DC)/DC conversion circuit includes an input end, a power circuit, and an output end, a bypass circuit that is a unidirectional conduction circuit, and a switch disposed between the input end and the power circuit, where the input end is configured to be coupled to an external power supply to receive power to the DC/DC conversion circuit. The bypass circuit is coupled between the input end and the power circuit, the bypass circuit is disposed between the switch and the power circuit, and the bypass circuit is coupled to the power circuit in parallel. The switch is configured to be closed when the input end is reversely coupled to the external power supply to enable a current from a positive electrode of the external power supply to flow back to a negative electrode of the external power supply through the bypass circuit and the switch.

Abstract: An inverter apparatus is disclosed in this application, which includes a plurality of protection units and a plurality of inverter units. For any protection unit, when a voltage at an input terminal of the protection unit is greater than a voltage at an output terminal of the protection unit, a path between the input terminal and the output terminal of the protection unit is in a forward conducted state; when the voltage at the output terminal of the protection unit is greater than the voltage at the input terminal voltage of the protection unit, the path between the input terminal and the output terminal of the protection unit is in a reverse cut-off state; and when a control terminal of the protection unit receives a first trigger signal, the path between the input terminal and the output terminal of the protection unit is in a reverse conducted state.

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 device for resolving common-mode voltage interference is applied to a power supply system including a power converter and a switch mechanism. Each phase of an output end of the power converter is connected to a downstream circuit by using the switch mechanism. The switch mechanism includes a first switch and a second switch. The device includes a controller and a passive component. Two ends of the first switch in at least one phase of the output end of the power converter are connected in parallel to the passive component, and the controller controls the second switch to be turned on, and when a voltage difference between the two ends of the first switch is less than a preset voltage, controls the first switch to be turned on. In this manner, the switch mechanism is protected, thereby prolonging a service life of the switch mechanism.

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 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 fault detection apparatus includes a temperature detection unit, a current detection unit, a controller, and a breaking unit. The temperature detection unit is configured to detect temperatures of the plurality of filter capacitors and output the temperatures to the controller. The current detection unit is coupled to the plurality of filter capacitors and is configured to detect currents of the plurality of filter capacitors and output the currents to the controller. The controller is separately connected to the temperature detection unit, the current detection unit, and the breaking unit, and is configured to: when the received temperature exceeds a first threshold and the received current exceeds a second threshold, control the breaking unit to be disconnected. The breaking unit is connected between the output end of the grid-tied inverter and the plurality of filter capacitors and is configured to be disconnected or connected under control of the controller.

Abstract: A converter includes a power conversion circuit, a switching device, and a controller, and includes N phases, where N is 2 or 3. An input end of the power conversion circuit is connected to a direct current power supply, and the power conversion circuit converts a direct current output by the direct current power supply into an alternating current. The switching device includes at least the following two stages: a first-stage switching device and a second-stage switching device. The first-stage switching device and the second-stage switching device separately include N switches, and the N switches are connected in series to the N phases respectively. An output end of the power conversion circuit is connected to an alternating current power grid through the first-stage switching device and the second-stage switching device that are connected in series.

Abstract: This application discloses a photovoltaic device, a photovoltaic inverter, a system, and a power limit control method. The device includes a DC-DC converter circuit, an inverter circuit, and a controller. An input end of the DC-DC converter circuit is connected to a photovoltaic array, and an output end of the DC-DC converter circuit is connected to an input end of the inverter circuit. The controller is configured to: receive a power scheduling instruction, where the power scheduling instruction carries a power reference value; and when the power reference value is less than a power at a maximum power point, reduce an input current of the DC-DC converter circuit; or when an input voltage of the DC-DC converter circuit is greater than or equal to a preset voltage, increase an input current of the DC-DC converter circuit until an output power of an inverter becomes consistent with the power reference value.

Abstract: A connector and an electronic device, to resolve a problem of poor mountability of the connector. The connector includes a housing, a conductive core, and a fastening structure. The housing has a channel that passes through a first end and a second end of the housing. The conductive core is disposed in the channel. A solder leg is disposed on one end of the conductive core, and the solder leg protrudes from the first end of the housing and is configured to be soldered to a circuit board. The fastening structure is configured to fasten the housing to a panel. The conductive core may be directly soldered to the circuit board, so that a connection effect between the conductive core and the circuit board can be improved, and mounting steps can be reduced.