Optimum Design of Interphase Reactor With Double-Tap Changer Applied to Multipulse Diode Rectifier

In this paper, the optimum turns ratio of an interphase reactor (IPR) with a double-tap changer is presented with mathematical analysis. The relation between the total harmonic distortion (THD) of the input current and the turns ratio is introduced, and based on the relation, the optimum turns ratio when the THD is minimal is obtained. Via another relation between the ripple coefficients of the output voltage and the turns ratio, the optimum turns ratio is derived when the ripple coefficient is minimal. Meanwhile, using the optimum turns ratio, a new formula to calculate the critical value of IPR is written. Some computer simulation results and experiments are included to support the theoretical analysis of optimum design.