Common-mode Voltage Suppression For A Five-phase Two-stage Matrix Converte

In some low-voltage and high-current application fields,multi-phase output converters have received extensive attention from scholars.Among them,the fivephase two-stage matrix converter(TSMC)has excellent characteristics such as good input and output performance,bidirectional energy flow and unity power factor.,has become a new type of high-efficiency AC-AC power converter with more development potential.However,since there is no energy storage element in the five-phase TSMC system,the two stages are directly coupled,which increases the difficulty of the control algorithm.Therefore,it is of great significance to study the control algorithm suitable for the five-phase TSMC.This paper takes the five-phase TSMC as the research object,and studies the suppression strategy of the system common-mode voltage for the problem of the high output common-mode voltage amplitude of the five-phase TSMC.Firstly,this paper expounds the basic principle of the traditional dual space vector modulation strategy of the five-phase TSMC system.According to its topology,the modulation strategy is divided into three parts,namely the rectifier stage modulation,the inverter stage modulation and the cooperative control method between the two stages.Then analyze the input-output relationship between the two stages.Secondly,the relationship between the five-phase inverter stage voltage vector and the system common-mode voltage is analyzed,and it is determined that the zero-voltage vector and the medium-voltage vector correspond to larger common-mode voltage amplitudes.Based on the dual space vector modulation strategy,the common-mode voltage spectrum is analyzed by double Fourier series,and the relationship between the low-frequency component of the common-mode voltage and the system input frequency and output frequency is obtained.Then,by studying the theoretical basis of the five-phase TSMC based on the finite control set model predictive current control(FCS-MPCC)algorithm and the mapping relationship of the voltage vector in the fundamental space and the harmonic space,this paper proposes two virtual vector-based FCS-MPCC algorithm achieves the goal of eliminating harmonic components in the harmonic space and suppressing the output common-mode voltage.Among them,the FSC-MPCC1 algorithm effectively eliminates the harmonic components in the harmonic space,and the FCS-MPCC2 algorithm improves the output steady-state performance of the system.Both control algorithms effectively suppress the common mode voltage and reduce the calculation of the digital controller.burden.Finally,the main circuit and control circuit of the five-phase TSMC system are introduced,and the results of the control algorithm proposed in this paper and the traditional algorithm are analyzed and compared.The results show that the two proposed FCS-MPCC algorithms based on virtual vector can effectively suppress the common mode voltage and improve the system output performance,which verifies the correctness and effectiveness of the proposed control algorithm.