Earticle

A comprehensive compensation device with paralleled decoupling for suppressing harmonics current, reactive power, and DC Bias of power transformer is proposed. Harmonics current and reactive current are detected by instantaneous reactive power theory. In this way, the fundamental active power is converted to be compensated reactive power and harmonics by controlling the converter. Compared to the ASVG with IGBT, the capacity and withstanding voltage level of ASVG with GTO are improved. The voltage across the devices of APF with multi-level inverter is reduced because of the paralleled decoupling connection. The harmonics compensation with multi-stage inverter can also reduce the voltage across the devices effectively. The reactive power compensator can work as a controllable rectifier and output controllable current by changing control algorithm. This current injects neutral point of transformer and suppresses its DC Bias, which has obvious effect on a power transformer. As a part of intelligent power grid, this compensator plays an important role for the development of smart grid automation.

In general, a power decoupling method using electrolytic capacitor is used to solve a problem that appears 120[Hz] ripple of grid at the PV module output. But electrolytic capacitor has a effect on the short lifetime and low reliability of PV system. Therefore, studies which replace the large electrolytic capacitor with small film capacitor have been researched in resent years. This paper proposes flyback inverter which can be replaced with film capacitor by connecting the circuit implementing zero voltage switching in PV side. The proposed system is validated by PSIM simulation.

본 논문에서는 전기자동차 온-보드 충전기용 단상전력변환시스템에서 능동전력디커플링 회로를 병렬로 연결하는 시스템 구조 및 그에 대한 제어 방법을 제시한다. 제안하는 시스템은 전기자동차 구동 인버터의 전력반도체와 구동모터의 고정자를 이용하여 능동전력디커플링 회로를 구성함으로 추가적인 부품을 최소화하고 전체 시스템의 전력밀도를 높임과 동시에 가격상승을 억제한다. 제안한 방식의 성능은 MATLAB/Simulink 시뮬레이션을 활용한 결과를 통해 비교 분석하였다.