BACKUP POWER SYSTEM AND POWER CABLE CONNECTION DETECTION METHOD THEREFOR

This application provides a backup power system and a power cable connection detection method therefor. When an on/off-grid controller is powered by an inverter or a power grid, a switch circuit in the on/off-grid controller is disconnected, and cable connection detection is started. When a voltage is detected at only an inverter-side port or a grid-side port of the on/off-grid controller, a cable connection fault of the grid-side port is reported if it is determined that the following conditions are met: The voltage of the inverter-side port is greater than a first threshold, an output voltage of the inverter is less than the first threshold, and the inverter is shut down or in a startup process. When voltages are detected at both the inverter-side port and the grid-side port, a disturbance instruction is sent to the inverter, for the inverter to adjust the output voltage based on the disturbance instruction. If it is determined that the voltage of the grid-side port changes with the output voltage of the inverter, a cable connection fault of the inverter-side port is reported. In the foregoing detection manner, no manual intervention is required for checking cable connection in supplying power by a single power supply, and no additional detection component needs to be added. This reduces costs, and features simple logic, fast speed, and accurate detection.