I. Introduction
Electromagnetic pollution of the power line introduced by power electronics systems includes harmonic distortion due to nonlinear loads, typically, rectifiers [1]. So various types of single-phase PFC converter circuits to improve the ac current waveform have been developed and used [2]–[6]. Main circuit configurations of PFC converter (a) by dc side inductance (b) ac side inductance. The conventional PFC converter is constructed by a boost chopper circuit with a switching device in the dc side of the diode bridge rectifier circuit [2]. Good characteristics such as a sinusoidal current waveform in phase with the ac line voltage and the constant dc voltage controlled by the reference voltage can be obtained from the conventional PFC converter control system. As the system, however, requires many sensors such as the dc voltage to control the value, the ac line voltage and the ac or dc current to control the sinusoidal current waveform, the PFC control system becomes very complicated and expensive and many sensors invite the reliability reduction of the converter.