A sinusoidal inverter is a power converter that converts DC voltage into AC voltage, and is widely used in many power conversion applications such as distributed generation and uninterruptible power supplies because it tracks the load voltage to the sinusoidal reference. Various controller design methods have been proposed to meet the control specifications of sinusoidal inverters, such as steady-state deviation from the sinusoidal reference, harmonic distortion, and robustness against load fluctuation.
　In the previous study, a controller design method based on the positive realness of the load was proposed, which guarantees robust stability and robust performance for arbitrary linear loads. However, the method has been unverified for nonlinear loads and harmonic distortions.

　In this paper, we propose a robust controller design method for sinusoidal inverters to track the voltage applied to arbitrary nonlinear loads. The effectiveness of the proposed method is demonstrated by simulations and experiments.