基于三相桥臂坐标的SVPWM过调制方法-吴德会.pdfVIP

2015 1 Vol.30 No. 1 30 1 TRANSACTIONS OF CHINA ELECTROTECHNICAL SOCIETY Jan. 2015 SVPWM 361005 SVPWM SVPWM SVPWM SVPWM PWM THD SVPWM TM46 A SVPWM Overmodulation Method Based on Three-Phase Bridge Arm Coordinates Wu Dehui Xia Xiaohao Zhang Zhongyuan Li Chao Xiamen University Xiamen 361005 China Abstract A new overmodulation method based on space vector pulse width modulation (SVPWM) is discussed, and the performance and harmonic components of which are also analyzed. Firstly, the essence of original overmodulation strategy in the classical SVPWM is investigated. Then, a three-phase-bridge-arm coordination is introduced in which the relationship between three up-bridge arm working situations is parallel. Finally, a unified solution of linear modulation and overmodulation is proposed, to avoid the calculation of the reference angle and holding angle in existing strategies. The new method cancels traditional sector division, simplifies the computation, and gives smooth transitions from linear modulation, overmodulation, to six-step operation finally. The overmodulation strategy is theoretically analyzed, simulated and experimented. The results demonstrate that the PWM wave generated by the new method is similar to the classic, and the total harmonic distortion(THD) of the output voltage is markedly reduced. Keywords Three-pha