Model predictive mean power control of PWM rectifier

Abstract

This paper proposes a mean active power control for pulse-width modulation (PWM) rectifier based on model predictive direct power control (MPDPC). Conventional MPDPC can achieve good steady state performance and quick dynamic response by minimizing a cost function relating to power errors. However, in two-level PWM rectifier, there are only eight discrete voltage vectors, which restricts the performance improvement of conventional MPDPC. The sampling frequency has to be high to achieve good steady state performance. As zero vector produces relative small power variations, this paper tries to incorporate the zero vector during one control period to achieve further steady state performance improvement. Only a fraction of control period is allocated to the non-zero vector obtained from conventional MPDPC and the duration is determined based on the principle of equaling the active power to its reference value in one control period. The presented experimental results prove that the proposed method produces lower power ripples and less current harmonics, while the dynamic response of conventional MPDPC is reserved.