A Robust Capacitance Control Method for Variable Active Capacitor

The active capacitor with variable capacitance control is able to actively and variably mimic the voltage-current characteristics of a physical passive capacitor; however, the existing capacitance control methods cannot achieve accurate capacitance control due to parameter and model errors. This article proposes a capacitance control method for the variable active capacitor with improved accuracy and robustness. It applies an iterative learning controller to realize equivalent capacitances according to given reference values. An 800-V/20-A active capacitor prototype is developed and tested under various dynamic operation conditions and circuit parameter shifts to verify the accuracy and robustness of capacitance control.