Space Vector Active Cancellation Method for the Zero Sequence Voltage on Gradationally Controlled Voltage Inverter without Transformers for LSM, in the Maglev Line

Abstract

We are developing a gradationally controlled voltage inverter without output transformers for LSMs in the Maglev Line. In this paper, we propose a space vector active cancellation method for the zero-sequence voltage to make it compatible with the forming sinusoidal wave. We explain the algorithm of this method, and demonstrate that the output voltage is compatible with the forming sinusoidal wave and that the THD of current is below 5% under the experimental conditions of few voltage levels and at low frequency. Also, the zero-sequence current was reduced to 10% in the inverter model with the active cancellation method.