Normalization Calculation Method of THD for Aviation Multipulse Rectifiers

There are differences between the analytical results and the experimental results of the input total harmonic distortion (THD) of aviation multipulse rectifiers due to the power factor angle. To obtain the accuracy value of THD and simplify the complicated computational process of THD, a normalization calculation method is proposed, and the relationship between the input voltage THD and the power factor angle of arbitrary aviation multipulse rectifiers is acquired. To verify the proposed normalization calculation method, the 12-pulse rectifier and the 24-pulse are taken as the example. According to the value of the input inductance, a series of models of aviation multipulse rectifiers are established. Based on the models, the relationships among the input inductance, input voltage, output resistance, and power factor angle are obtained. On the basis of the relationships, the THD of the input voltage based on the power factor angle is calculated. The calculation results of THD are consistent with the results of the proposed normalization calculation method. The testing results show that the normalization calculation method of THD is applicable to the 12-pulse rectifier, the proposed 24-pulse rectifier, and the previous studies. The method has simple calculation and high accuracy, and is significant to obtain the exact input THD value of arbitrary aviation multipulse rectifiers.