Analog control of closed loop 24 pulse rectifier (simulation and hardware)

Multi-pulse converters are developed for ac dc conversion with reduced harmonic currents and reactive power burden, low EMI, RFI at input ac mains and good quality low rippled dc output. Diode rectifier and phase controlled thyristor rectifiers are popular in several industrial applications such as chemical processes, DC arc furnaces, HVDC transmission systems etc. In this paper the simulation and hardware of closed loop control of 24-pulse converter is presented. The special phase shift transformers are designed to get required phase displacement. This 24 pulse rectifier has been designed for high voltage / current application by connecting them in series/parallel respectively. Here the entire closed loop approach is explained which can be utilized for HVDC transmission.