Research On Modulation Strategy Of Five-phase Two-stage Matrix Converter

In recent decades,power electronic converters have been widely used in the AC electrical drive system because of its advantages.With the rapid development of power electronic technology,multi-phase motor drive systems provide a new way to achieve high-voltage high-power AC transmission.And the multi-phase power converter,which is used to drive multiphase motor has been widely used and studied.Two-stage matrix converter is a new type of AC/AC power converter,which has great potential in the development of power electronic converter.Taking a typical topology of five-phase two-stage matrix converter as the research object,the research on its control strategies is conducted,which lays the foundation for further theoretical research of multi-phase matrix converter.Based on the topology of five-phase two-stage matrix converter,the space vector pulse width modulation(SVPWM)strategy is studied,and the duty ratios at both stages are derived.Then,the general expression of the modulation signals is derived based on the duty ratios by using only one symmetrical triangular carrier signal.Finally,a carrier-based PWM method based on SVPWM strategy is realized by logic operation,which avoids the complexity of the sector combination and lookup tables of SVPWM strategy.In order to reduce the common-mode voltage(CMV)generated by the five-phase two-stage matrix converter,a carrier-based PWM method is proposed to reduce the CMV of five-phase two-stage matrix converter.On the basis of the SVPWM strategy,the large CMV is avoid by the reasonable selection and distribution of zero vector in the inverter stage.Finally,the general expression of the corresponding modulation signals is deduced by combining the carrier signal,and the driving signal of each switch is obtained.This method reduces not only its CMV,but also the number of commutations within a modulation period.Finally,the simulation model of five-phase two-stage matrix converter is established by MATLAB/Simulink.And the simulation results prove the feasibility of the theoretical method.