Improved model predictive control scheme for AC/DC matrix converters by considering input filter power ripple under imbalanced grid voltage conditions

다국어 초록 (Multilingual Abstract)

The power ripple in the input filter is normally ignored in the conventional model predictive control scheme (MPC) of an AC/DC matrix converter under imbalanced grid voltage conditions. Unfortunately, this power ripple causes output power and current ripples. Some methods compensate this power ripple to obtain a ripple-free output current. However, these methods are generally complicated due to the increased computational and control burden or the use of a digital filter to estimate the power ripple. Moreover, the compensation of power ripple results in current distortion on the grid side, which has yet to be fully addressed. This paper presents an improved MPC scheme to simultaneously compensate input filter power ripple and reduce grid current distortion under imbalanced grid voltage conditions. The power ripple is calculated based on the grid voltage and its 90 electrical degrees delay signal, which makes the implementation simple without grid voltage components extraction or digital filter design. Furthermore, a closed-loop current controller is proposed to reduce the harmonic distortion of the grid current. The feasibility of the proposed MPC scheme is confirmed by both simulation and experimental results.