A digital excitation regulator of arc-suppression coil with even frequency reverse electromotive force load based on digital signal processor (DSP) is presented. The proposed regulator controls the excitation current of arc-suppression coil with magnetic bias through the linearization between the output of PI regulator and trigger angle. It can filter and average the excitation current to eliminate the infection of even frequency harmonious waves and give the measurement of excitation current precisely

which simplifies the program and makes excitation current run after input quickly. The digital trigger to silicon controlled rectifier based on field programmable gate array (FPGA) has high accuracy and the ability of phase self-adjusting.