Effects of Line and Load Conditions on TRU and ATRU Input Current Harmonics

This paper presents modeling and analysis of the harmonic performance of multi-pulse Transformer-Rectifier Units (TRU) and Autotransformer-Rectifier Units (ATRU) under different non-ideal operation conditions. Other than numerical simulations, the paper presents an analytical method to quantify and study the effects by describing the operation of the converters by the so-called mapping functions. Double-Fourier series method is applied to determine the Fourier representation of the mapping functions. Based on the analytical models in the frequency domain, the effects of harmonic voltage and load current harmonics are theoretically investigated.