A 24-Pulse AC-DC Converter for improving power quality using fork connected transformer

The existing AC-DC converter using a transformer which does not meet the standard requirement at varying loads and also causes the low power factor which is responsible for a series of problems caused in electrical system. This resulting in increased losses in conductor, error introduced in measuring equipment, malfunction of other equipment connected to mains due to distortion of line voltage. So, a 24-pulse AC-DC converter is designed and simulated to feed isolated industrial loads. The proposed configuration consists of an isolation transformer based fork connection. This improves the power quality at AC mains and it meet IEEE-519 requirement at varying loads. The power quality indices such as THDi, THDv, distortion factor (DF), displacement factor (DPF), and power factor (PF) in AC main at varying load. The set of power quality indices on input AC mains for load fed from 6-pulse, 12-pulse and 24-pulse AC-DC converter performance are compared and analyzed. It is observed that input current total harmonic distortion (THD) of less than 5% is possible with proposed topology of 24-pulse AC-DC converter for improving power quality using fork connected transformer.