The Harmonic Characteristic Of The Advanced Synchronous Svpwm Overmodulation Strategy

The speed range of the rail transit traction system is very wide and mostly uses the hybrid pulse width modulation. The traditional hybrid pulse width modulation requires different types of modulation strategies to cooperate in switching, which inevitably leads to current and torque ripple and complicates the modulation strategy. In order to solve this problem, this paper proposed an advanced synchronous SVPWM overmodulation method, which can greatly simplify the entire modulation strategy. The modulation method is theoretically analyzed and its detailed mathematical expressions are obtained in this paper. Based on the mathematical expression, this paper analyzed the harmonics of the advanced synchronous SVPWM overmodulation strategy and compared it with that of SHE-PWM. Finally, the simulation and experimental verification of the modulation method are carried out, which proves that the method has simple and efficient and excellent harmonic characteristic.