A MPC based common-mode voltage suppression strategy for PMSG used in high power wind generation system

Abstract

The conventional model predictive control (MPC) method applied to permanent magnet synchronous generator control adopts all the seven voltage vectors (VVs), including one zero VV and six nonzero VVs, to implement the predictive current control in order to improve the current control performance. However, the common-mode voltage (CMV) is large due to the use of zero VV. Although the MPC strategy only using six nonzero VVs can reduce the CMV, its switching frequency is relatively high due to the switch between non-adjacent VVs. In this paper, a novel MPC based CMV suppression strategy for PMSG used in high power wind generation system is proposed. In the present method, only four nonzero VVs, including three adjacent nonzero VVs and one non-adjacent nonzero VV, are utilized to perform the optimization in every sampling period, resulting in switching frequency and calculation amount reduction with no adverse effect on the current response. The experimental results confirm the effectiveness of the proposed strategy.