Modified Space Vector Modulation with Low Bandwidth Sensor to Reduce Losses in Soft Switching Three-phase Inverters

Space Vector Modulation Zero Voltage Switching Topology (SVM-ZVS) offers simple control for DC-link resonant three-phase converters but suffers from lower efficiency due to hard switching when one of the phase currents becomes zero or close to zero. Moreover, the SVM-ZVS topology does not correctly address the delay issues that come from the controller implementation and sensors, which are critical for maintaining soft-switching. This paper proposes a Modified Space Vector Modulation Zero Voltage Switching (MSVM-ZVS) to reduce the losses which is particularly beneficial for soft-switching at low levels of phase currents. Moreover, the proposed MSVM-ZVS also properly addresses the delay issues and can maintain soft-switching even if the zero crossing current is not properly detected; this relaxation of sensing requirement enables the use of low bandwidth, low cost current sensors. The MSVM-ZVS has been verified in simulation, and it is observed that the proposed topology works better than SVM-ZVS in terms of efficiency and the current stress of the switches. Simulation results shows the efficacy of the proposed modulation scheme.