Application of Third-Order Harmonic Voltage Injection in a Modular Multilevel Converter

作者：Guo, Gaopeng; Song, Qiang^*; Yang, Wenbo; Wang, Yu; Liu, Wenhua; Rao, Hong; Xu, Shukai

来源：IEEE Transactions on Industrial Electronics, 2018, 65(7): 5260-5271.

DOI：10.1109/TIE.2017.2777413

• Capacitor ripple voltage
• modular multi-level converter (MMC)
• third-order harmonic voltage injection (THVI)
• utilization rate of capacitor voltage
• voltage modulation

This study adopts the method of third-order harmonic voltage injection (THVI) to move the peak value of a reference voltage toward the high capacitor voltage and increase the utilization rate of the capacitor voltage. This method can lower the cost or enlarge the capacity of a modular multilevel converter (MMC) when applied in high-voltage direct-current transmission. In this paper, the principle of THVI is introduced. Two calculation methods for modulation waves are studied, and the mathematical expressions of the capacitor voltage under all operating conditions are deduced. Thus, the optimal magnitude and phase of the third-order harmonic voltage are determined under all operating conditions. The mathematical expressions of the optimal magnitude and phase of the third-order harmonic voltage are obtained, and their online calculation burden is reduced. Simulation and experimental results show that the proposed method of THVI is feasible and effective.

• 出版日期2018-7
• 单位南方电网科学研究院有限责任公司; 清华大学