시지연과 SVPWM 영향이 고려된 새로운 제어 모델에 의한 3상 전압원 PWM 컨버터의 전류 제어

Current Control of a 3$\phi$ PWM Converter Based on a New Control Model with a Delay and SVPWM effects

In design of a digital current controller for a 3$\phi$ voltage-source (VS) PWM converter, its conventional model, i.e., stationary or synchronous reference frame model, is used in obtaining its discretized version. It introduces, however, inherent errors since the following practical problems are not taken into consideration: the characteristics of the space vector-based pulsewidth modulation (SVPWM) and the time delays in the process of sampling and computation. In this paper, the new hybrid reference frame model of the 3$\phi$ VS PWM converter is proposed considering these problems. In addition, the direct digital current controller based on this model is designed without any prediction or extrapolation algorithm to compensate the time delay. So the control algorithm is made very simple. The validity of the proposed algorithm is proved by the computer simulation results.