A Current Control Method With Extended Bandwidth for Vienna Rectifier Considering Wide Inductance Variation

Abstract

Wide inductance variation of powder core inductors used in the Vienna rectifier challenges the system stability and limits the bandwidth of the current loop, which leads to more harmonics. In this article, a current control method with extended bandwidth is proposed for a three-phase Vienna rectifier to improve the system stability and reduce harmonics. The averaged model of three-phase Vienna rectifier considering the inductance variation is derived in the natural a-b-c frame. The impact of inductance variation on control system is analyzed. To extend the control bandwidth, the instantaneous inductance is obtained based on a piecewise linearization method and is embedded into a classical current control loop. Since the control method is easy to implement and occupies a little time of digital controller, the sampling frequency can be increased to twice the sampling frequency, which makes the bandwidth further extended. The proposed method keeps a wide and fixed bandwidth of the current loop, which improves the harmonics reduction ability and dynamic performance compared with classical control methods. Finally, the effectiveness of the proposed method is verified by a three-phase Vienna rectifier prototype.