Modeling and compensation of inverter nonlinearity effects in carrier signal injection-based sensorless control methods from positive sequence carrier current distortion

Although the inverter nonlinearity is caused by several different factors, the deadtime and parasitic capacitance effects are major contributors to the carrier signal distortion in carrier signal injection-based sensorless techniques. According to the experiments, this paper establishes the disturbance voltage model of inverter nonlinearity effects for carrier signal injection techniques, which comprises of both fundamental and high-frequency voltage distortion components. With the help of such disturbance voltage model, a new compensation scheme based on the distortion of positive sequence carrier current is developed. Finally, experimental results confirm the effectiveness of proposed method in suppressing the influence of inverter nonlinearity on the rotor position estimation.