SWITCHING MODULE AND POWER SUPPLY SYSTEM

A switching module includes mechanical relays, semiconductor switches, voltage detectors to detect an input voltage to a power converter, and a controller. When the controller determines that the waveform of the input voltage is abnormal during a first determination period, the controller outputs an open command signal to mechanical relays corresponding to a power source electrically coupled to the power converter. When the controller subsequently determines that the waveform of the input voltage is normal during a second determination period, the controller outputs a close command signal to the mechanical relays.