Research On Carrier Based PWM Modulation Strategy Of Z-source Two-stage Matrix Converter

In recent decades,power electronic technology has developed rapidly,and power electronic converters have received widespread attention.As the AC-AC converter,the matrix converter has simple structure and excellent performance.It has attracted extensive attention from scholars at home and abroad.The matrix converter is a power converter based on bidirectional switches.The input and output current waveforms are all sinusoidal,with less harmonic content and less pollution to the power grid.And the input power factor can be 1.Therefore,it is regarded as the green AC-AC converter.However,the maximum voltage transfer ratio of the 3×3 matrix converter is only 0.866,which limits its practical application.In order to solve this problem,this paper introduces the Z source network into the two-stage matrix converter and constructs the Z-source two-stage matrix converter.In the Topology,based on the topology and theory of the three-phase Z-source inverter,a Z-source network is added between the rectifier stage and the inverter stage of the two-stage matrix converter to obtain the Z-source two-stage matrix converter.On the modulation strategy,the duty cycles of the rectifier stage and the inverter stage are derived based on the space vector pulse width modulation strategy(SVPWM).Then,a symmetric triangular carrier signal is constructed,and combined with the obtained duty cycles,the modulation wave expressions of the rectifier stage and the inverter stage are calculated.Then,by analyzing the inserted mode of the shoot-through state,the inserted position is adjusted,so that the modulation wave expression of the shoot-through state is simple and regular.Finally,the modulation waves are compared with the high-frequency carrier,and the drive signal for controlling each switch is generated by logic operation,thereby realizing the modulation of the carrier-PWM(CBPWM)strategy for the Z-source two-stage matrix converter.This method avoids the sector division of the SVPWM strategy and reduces the complicated trigonometric function calculation,which is beneficial to the implementation.Finally,the Z-source two-stage matrix converter simulation model is built in the Matlab/Simulink component library.And it is simulated by SVPWM strategy and CBPWM strategy respectively.The simulation results show that the Z-source two-stage matrix converter has good output performance based on the CBPWM modulation strategy.The corresponding program design is reasonable,and the theoretical analysis is further verified.The correctness and feasibility of the proposed modulation strategy are proved,which provides a reference and basis for the practical research of Z-source matrix converter.The theoretical analysis is further verified.It proves the correctness and feasibility of the modulation strategy proposed in this paper,which provides the reference for the practical research of Z-source matrix converter.