Parallel conversion control method with closed-loop selection backup protection

The invention relates to parallel conversion control, in particular to a parallel conversion control method with closed-loop selection backup protection, and the parallel conversion control method with closed-loop selection backup protection can detect a closed-loop current value in real time and execute preset control logic according to a detection result. Executing a parallel conversion program under the condition that the parallel condition is met, and if the loop closing current exceeds the value, skipping off an execution switch; and if the loop closing current is lower than the threshold value, the conversion is smoothly completed. The loop closing current detection device utilizes a hardware circuit to realize logic detection and judgment and outputs an action signal according to a current comparison result, and in parallel conversion control logic, on one hand, the loop closing current detection device serves as a signal receiving device to receive an output signal from a controller and is matched wit