Effect of Different Selective Harmonic Elimination Solution Sets on Harmonic Distortion and Induction Motor Losses

High-power medium voltage frequency converters, often used in railway applications, are typically operated at low switching frequencies to reduce IGBT switching losses and ensure that junction temperatures remain within acceptable limits. However, operating at low switching frequencies can introduce unwanted harmonic distortion in the stator current, which increases losses in induction motors. To mitigate this, advanced pulse-width modulation (PWM) techniques, such as selective harmonic elimination (SHE), are employed to minimize harmonic content. The SHE approach is known to produce multiple sets of solutions, but it remains unclear whether specific solution sets offer superior performance. In this paper, the impact of different SHE-PWM solution sets on the weighted total harmonic distortion (WTHD) of the stator current and induction motor losses is investigated. Analysis aims to identify which SHE solution sets provide optimal performance by minimizing harmonic distortion and motor losses, thus contributing to improved motor efficiency in railway applications.