Park's currents linear control stability analysis of the PWM voltage converter connected to the AC mains

This paper presents the stability analysis of a Park's currents linear controller of the PWM voltage converter connected to the AC mains. The converter AC voltages are generated by a PWM control circuit. It is shown that the system can be a minimum or nonminimum phase stable system depending on the operating point. The system controlled through the PWM control circuit is a coupled system. A decoupled controller is presented. The decoupled controller transforms the system in a minimum phase stable system. The two Park's currents components are controlled independently acting in the decoupled controller. The influence of errors in the decoupled feedback variables is analyzed with respect to the system zeros and eigenvalues position. For high values of the currents controllers natural frequency the system is insensitive to the decoupled feedback variables errors. Thus a simplified Park's currents control circuit is presented.