Abstract: Design of a tapped star transformer based 36-pulse ac-dc converter is presented in this paper. The 36-pulse topology is obtained via two paralleled 18-pulse ac-dc converters each of them consisting of a 9-phase (9-leg) diode bridge rectifier. A transformer is designed to supply the rectifiers. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. For independent operation of paralleled diode-bridge rectifiers, a zero sequence blocking transformer (ZSBT) is designed and implemented. Connection of a tapped inter-phase transformer (IPT) at the output of ZSBT results in doubling the number of output voltage pulses to 72. The proposed structure has been implemented and simulated using Matlab/Simulink software under different load conditions. Simulation results confirmed the significant improvement of the power quality indices (consistent with the IEEE-519 standard requirements) at the point of common coupling. Results show that input current total harmonic distortion (THD) is less than 3% for the proposed topology at variable loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation.
کلید واژگان :AC–DC converter, tapped star transformer, power quality, 72-pulse rectifier, Pulse doubling, direct torque controlled induction motor drive
ارزش ریالی : 300000 ریال
با پرداخت الکترونیک