Genetic-algorithm-based solution in PWM converter switching

To minimise the PWM converter switching frequency and to keep the losses to a minimum, a topology is presented composed of two identical front-end voltage source rectifiers connected in parallel to a three-winding transformer. This topology uses the transformer connection to remove the harmonics of the order 6k +/- 1(k= 1,3,5....). Additional harmonics lower than the 23rd are eliminated by a suitable PWM-SHE switching pattern obtained through a genetic-algorithm-based solution of the switching angles. Such a novel and efficient approach opens up the possibility of online solution, and fast implementation of PWM switching in high-power converters. The resulting converter system presents all the advantages associated with active front-end rectifiers with the purpose of ensuring near unity power factor operation. The genetic-algorithm-based simulation and experimental results confirm the feasibility and advantage of the proposed drive system.