Method for Discontinuous Current Mode Compensation of Line-Commutated Converters

Abstract

The implementation of a new method to control linecommutated converters in discontinuous conduction mode is presented. The method is based on the modification of the thyristor's firing angle α using a linear approximation, yielding nearly the same dynamic performance as in continuous conduction mode. The firing angle is corrected by adding a supplementary angle ∆α, calculated by estimating the average output current. The proposed technique significantly reduces computational burden, thus being suitable for online calculation. Both simulations and experimental results are presented on a 1-kW laboratory prototype.