Based on the changes in input voltage from the power grid, intelligent detection is performed using a microcomputer (MCU+PLD+12-bit high-speed AD) to convert the analog signals of the changing voltage into digital signals. The microcomputer processes the data through pre-programmed instructions and outputs commands to be transmitted to the optoelectronic coupler controlling the rapid switching of the electronic module (IGBT or SCR). The output voltage stability is maintained by the transformer operating at the same frequency, phase-locked, and compensating for sine wave overlay.