RELAY MONITORING DEVICE, DUAL POWER SUPPLY SWITCHING CONTROL DEVICE AND RELAY MONITORING METHOD

The invention relates to a relay monitoring device, a dual power supply switching control device and a relay monitoring method, which can automatically eliminate the subsequent risks caused by fusion welding and have a low cost. The relay monitoring device comprises a relay fusion welding monitoring unit, for monitoring whether contacts of two relays in a power supply conversion unit in the dual power supply switching control device are fusion welded, and the two relays are respectively used for connecting one power supply of the dual power supply; a control unit for controlling the power supply conversion unit to connect one power supply of the dual power supply to a switching execution unit in the dual power supply switching control device through the corresponding relay, and controlling the switching execution unit to connect the one power supply to a main line; and an alarm unit for alarming to a user in the case that the contacts of at least one relay are fusion welded, wherein the control unit controls the power supply conversion unit not to connect any power supply of the dual power supply and controls the switching execution unit not to execute the power supply switching of the main line in the case that the contacts of at least one relay are fusion welded.