FAULT DETECTION APPARATUS AND METHOD, AND GRID-TIED PHOTOVOLTAIC POWER GENERATION SYSTEM

This application provides a fault detection apparatus and method, and a grid-tied photovoltaic power generation system, to improve accuracy of filter capacitor failure detection and ensure stable running of the grid-tied photovoltaic power generation system. The fault detection apparatus includes a temperature detection unit, a current detection unit, a controller, and a breaking unit. The temperature detection unit is coupled to a plurality of filter capacitors between an output end of a grid-tied inverter and a grid, and 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.