Carrier‐based PWM control strategy for Z ‐source two‐stage matrix converter

Abstract

In the Z -source two-stage matrix converter (ZSTSMC), the unique shoot-through state of the Z -source network can increase the voltage transfer ratio. Its maximum value can reach 4.33. In order to solve the complexity of space vector pulse width modulation (SVPWM) for ZSTSMC, a carrier-based PWM (CBPWM) control strategy is proposed. The duty ratios of the rectifier stage and inverter stage are calculated by the SVPWM method. A carrier is constructed and combined with duty ratios to produce regular modulation waves of rectifier stage and inverter stage. Then, the inserted mode of the shoot-through state is optimised by analysing. The position of its insertion is adjusted so that the expressions of the shoot-through modulation wave is simple and regular. And the number of modulation waves is reduced from 5 to 4. Next, the modulation waves are compared with a carrier to obtain pulse signals which are used to produce driving signals through logic operation. The ZSTSMC is controlled by this strategy to obtain three-phase symmetrical sinusoidal input and output waveforms. The proposed method is identical in output to the SVPWM method. Finally, the experimental results are provided to verify the feasibility and validity of the proposed method.