Gamma Modulation Based Three-Phase Two-Level Voltage Source Inverter For Reduced Switching Losses With Dynamic Load Changes

The article investigates the impact of different types of Bus clamping PulseWidthModulationmethods on the switching losses of a voltage source inverter. A controller based on a generalised modulation algorithm inspired by Bus Clamping PulseWidth Modulation is presented in this study. The implementation of the controller is based on the fact that for continual and split clamp PWM there exists a unique value of clamping position (gamma) for every load power factor angle, which results in minimum switching losses. The algorithm aims to minimise switching losses by combining and generalising all the unique values of clamping positions for continual and split clamp PWM. The controller dynamically adjusts the modulation technique and clamping position based on the sensed load phase current, resulting in reduced switching losses across the whole spectrum of load power factor angles compared to fixed clamping positions. Experimental and analytical evidence demonstrates the effectiveness of the proposed controller in achieving minimum switching loss operation during dynamic load changes.