On the cascade control system tuning for shunt active filters based on modulus optimum criterion

This paper focuses on the control system for the output current and voltage across the DC capacitor of a three-phase shunt active filter. A classical PI-PI cascade control solution is taken into consideration. The design of both inner current loop and outer voltage loop is based on Modulus- Optimum criterion. It is pointed out that this tuning approach provides a good phase margin. In order to finalize the voltage controller tuning, the passband of the unity feedback system is imposed. Simulations were performed under Matlab-Simulink environment and the results are presented to show the effectiveness of such tuning technique. Moreover, the experimental results agree with the simulated waveforms of the current supply.