3 results about "Potential induced degradation" patented technology

The utility model provides a potential induced degradation repairing device and a photovoltaic power generation system. The device is connected with the alternating current end of an inverter in the photovoltaic power generation system. The device comprises a rectification unit, a positive DC bus, a negative DC bus, a virtual neutral point, a first capacitor, a second capacitor, a third capacitor, a bus selection unit, a voltage regulation unit and a control unit. The control unit is connected with the rectification unit, the bus selection unit and the voltage regulation unit. The potential between the bus and the functional ground is increased through the voltage regulating unit and the bus selection unit, so that the potential to ground of the middle point BUSN or the alternating current end of the inverter is changed, and the potential to ground of the negative electrode or the positive electrode of the photovoltaic module is indirectly increased; the compatibility and reliability of the system are improved, the cost of the system is not increased, and centralized management and maintenance are facilitated.

Provided are a potential induced degradation (PID) repair circuit and PID repair method for a photovoltaic (PV) system. The PV system includes a solar cell module, an energy storage module, a direct current direct current (DCDC) boost circuit, and an inverter circuit; the PID repair circuit includes a DC power supply and an isolation circuit; after the DC power supply is processed by the isolation circuit, one end of the isolation circuit is connected to a positive terminal PV+ or a negative terminal PV- of the solar cell module, and another end of the isolation circuit is connected to a ground terminal PE; and a first switch is disposed on a connection path between the solar cell module and the energy storage module; PID repair is performed on the solar cell module by applying a negative voltage to the positive terminal PV+ of the solar cell module or a positive voltage to the negative terminal PV- of the solar cell module via the DC power supply; and a connection path between the solar cell module and the inverter circuit is disconnected during the PID repair. This application can prevent an internal short circuit caused by the inverter circuit during the PID repair, thereby effectively guaranteeing the operational safety of the PV system.

Embodiments of the present application provide a power supply system. By means of cascade of output ends of power supplies or DC-DC units, the output voltage is increased, the current between the power supplies or DC-DC units and DC-AC units is decreased, and the problems of costs and losses of cables from the power supplies or DC-DC units to the DC-AC units are solved. Moreover, the power supply system provided by the embodiments of the present application can also reduce the number of the cables from the power supplies or DC-DC units to the DC-AC units by means of cascade of the output ends of the power supplies or DC-DC units and input cascade of the DC-AC units, thereby reducing system costs. Moreover, in the power supply system provided by the embodiments of the present application, the input cascade and output isolation of the DC-AC units can reduce the specifications of a power conversion device. The problems of inadequate specifications and high cost of power conversion devices in existing industry are solved. In addition, the power supply system provided in some embodiments can also solve the problem of Potential Induced Degradation (PID) caused by a negative voltage of a battery plate to the ground when the system is running.