Observer-based inverter disturbance compensation

Most inverter disturbance compensation methods are based on open-loop inverter disturbance estimation. Because of measurement error and switching device parameter uncertainties, the inverter disturbance is not always compensated well. This paper proposes a closed-loop voltage disturbance observer and an observer-based inverter disturbance compensation method to improve the compensation. The performance and limits of the voltage disturbance observer and compensation system are analyzed in detail. Analytical and experimental results are provided to verify the performance. The results are particularly relevant when the inverter is used to inject signals for self-sensing.