Generalized Space-Vector-Modulation Method for Soft-Switching Three-Phase Inverters

Three-phase inverters are usually required to output reactive power in electric machine drives, renewable energy generation, static var generators, and other power electronic systems. Therefore, the inverter may operate within wide power factor angle range. However, the traditional zero-voltage-switching space vector modulation (ZVS-SVM) method for three-phase inverters is only applicable when power factor angle is between -π/6 and +π/6. In this article, a general ZVS-SVM method for three-phase inverter with arbitrary output is proposed. The principles for vector selection and vector sequence arrangement are discussed in detail. With only one switching operation of the auxiliary switch in each switching cycle, ZVS of all switches can be achieved. Operation stage analyses and ZVS condition of the inverter with the proposed method are introduced. In addition, the resonant parameters design considerations and loss analyses are investigated. Finally, the proposed ZVS-SVM method is verified by the experiment.