Improved Modulation Strategy for Three-Phase Matrix Converter-Based WPT System

In this article, an improved modulation strategy for the three-phase matrix converter (MC)-based wireless power transfer (WPT) system is proposed to enhance the system security and reduce the total harmonic distortion (THD) of the grid current. By analyzing the effect of the switching delay on the standard current space vector PWM (CSVPWM), it is revealed there is a risk of the over-voltage and overcurrent faults in the process of the vector switching. It also causes the synthesis current vector length error and causes the grid current distortion. To enhance the security and reliability, a switching logic of the current vectors suitable for both the resonant and nonresonant states of the compensation network is proposed; furthermore, an optimal calculation method of the effective current vector switching moments is proposed to reduce the grid current THD. The feasibility and practicability of the proposed modulation strategy are verified by the experiments.