Method and apparatus for resonance point following operation of a power conversion device

The present invention relates to a method for a resonance frequency following operation of a power converter and an apparatus thereof for stably operating a power converter system by operating at a frequency close to the resonance point following an impedance variation of a load side at the power converter that performs the resonance frequency following operation. The method for a resonance frequency following operation of a power converter comprises the steps of: detecting a phase difference of a voltage and a current supplied to the load to perform the efficient resonance following operation at the power converter; checking whether the detected phase difference is smaller than a minimum phase difference allowable value; setting a capacitor connecting required plug if a time, for which the detected phase difference is smaller than the minimum phase difference allowable value, is longer than a predetermined time; and connecting a resonance capacitor and a first capacitor in parallel after a stop of the power converter based on a set value of the capacitor connecting required plug. 전력변환기에서 효율적인 공진점 추종 운전을 하기 위해 부하 측으로 공급되는 전압과 전류의 위상차를 검출하고, 상기 검출된 위상차가 최소 위상차 허용값보다 작은지를 체크하고, 상기 검출된 위상차가 상기 최소 위상차 허용값보다 작은 시간이 소정 시간 이상 지속되면 커패시터 연결 필요 플래그를 세트하고, 및 상기 커패시터 연결 필요 플래그의 세트값에 기초하여 상기 전력변환기의 정지 후 공진 커패시터와 제 1 커패시터를 병렬로 연결한다.