PUBLICATIONS

This thesis introduces a Pulse Width Modulation (PWM) technique to minimize output voltage distortion for mitigating motor overvoltage caused by the reflected wave phenomenon. Motor drive systems with long transmission lines experience voltage reflection and overvoltage at motor terminals when high dv/dt switches are used because of impedance mismatch. Various PWM-based techniques have been investigated to suppress this overvoltage. The reference voltage generated by conventional methods, such as the Maximum Minimum Pulse Technique (MMPT) and the Pulse Elimination Technique (PET), is analyzed based on the operating region. These methods distort the voltage waveform and degrade the output current characteristics. Severe degradation in output current may lead to control instability. The proposed PWM technique minimizes output voltage distortion by generating an improved reference voltage through a hybrid approach that combines conventional methods guided by the output voltage error. Its effectiveness was verified through simulations and experiments, demonstrating significant improvements over conventional techniques.