Y-Source Two-Stage Matrix Converter and Its Modulation Strategy

Aiming at the defect of low voltage transfer ratio of two-stage matrix converter(TSMC), the proposed topology combines the Y-source network with the TSMC to form the Y-source two-stage matrix converter(YSTSMC) in this paper, and proposes its modulation strategy. The Y-source network is located in the dc-link of TSMC, and uses a tightly coupled inductor with three windings to transfer energy, which can increase voltage transfer ratio. Based on the mathematical model of the Y-source network, a small-signal model is established and dynamic analysis is performed. The analysis result of the impact of the output voltage of the rectifier stage on the output voltage of the system can be obtained. The space vector pulse width modulation (SVPWM) strategy is proposed to control YSTSMC, and according to the fluctuation of dc-link voltage, the modulation ratio of inverter stage is corrected in real time. By analyzing the voltage transfer ratio of YSTSMC, and the calculation expression of the maximum voltage transfer ratio is obtained. Finally, the experimental results are provided to verify the feasibility and validity of the proposed method.