Fast current control for thyristor rectifiers

In the paper a new method of current control for thyristor rectifiers with slow varying voltage generator type loads (battery chargers/dischargers, DC motors etc.) is described. The proposed control method is based on calculating the thyristor firing angle from a predicted voltage-time area on the DC side inductor. Thyristors are fired when the sum of the measured instant value of the DC current and the predicted current rises due to the voltage-time area on the DC side inductor becoming equal to the preset reference value. The proposed control method is tested and verified on a laboratory prototype system.