Active commutated thyristor CSI for grid connected photovoltaic applications

A new three phase active commutated thyristor current source inverter (CSI) topology is proposed for grid connected photovoltaic systems. Space vector PWM with a special switching sequence, which ensures proper commutation of thyristors, is implemented. In order to suppress the natural frequency of oscillations of LC filter and to ensure stability of the system, a charge controller in synchronous rotating reference frame is described. This allows easy design of PI controller gains. The simulation results of a 7-kVA inverter are presented.