DIRECT CURRENT JUNCTION BOX, PHOTOVOLTAIC POWER GENERATION SYSTEM, AND FAULT DETECTION METHOD

This application discloses a direct current combiner box, a photovoltaic power generation system, and a fault detection method. 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. According to the direct current combiner box provided in this application, when the direct current combiner box or a cable connecting to the direct current combiner box is faulty, a voltage transmitted by the photovoltaic array to the input end of the direct current combiner box may be reduced to a safety voltage, so that safety of personnel on site can be protected.