The excitation regulator of the self-excited static rectifier excitation system has evolved from discrete semiconductor components to integrated solid-state components, and from analog to digital. Domestic devices can be classified into three major categories: semiconductor analog excitation regulators, microcomputer (including programmable controllers) digital excitation regulators, and hybrid microcomputer (including programmable controllers) analog excitation regulators. Domestic semiconductor excitation regulators have had export records since the early 1970s. The research and development of microcomputer excitation regulators began in the late 1970s. In 1985, the WLT-1 excitation regulator produced by NARI Electric Company was first put into operation on the 50MW unit of Chitang Hydropower Station.