Comprehensive Investigation of Efficiency Improvement in Voltage Source Inverter Using Hybrid Carrier-Based Modulation

Voltage Source Inverters (VSIs) are essential in variable-speed drive applications, where Pulse-Width Modulation (PWM) signals are typically generated using a fixed-carrier (FC) signal. Increasing the FC frequency helps smoothen the inverter’s output current, improving motor performance. However, this comes at the expense of increased switching losses, reduced efficiency, and potential thermal management challenges. The Hybrid Carrier-based PWM (HCPWM) technique presents an alternative by dynamically alternating between two sawtooth carrier signals with different frequencies. This method aims to achieve higher efficiency without compromising system performance. However, selecting optimal carrier pairs to maximize efficiency across various speed and load conditions while maintaining total harmonic distortion within acceptable limits remains a challenge. This study provides a comprehensive experimental evaluation of the HCPWM approach, benchmarking it against conventional FCPWM. The results demonstrate that HCPWM enhances energy efficiency under all tested conditions, making it a viable and cost-effective solution for VSI-driven motor applications without introducing additional system cost or complexity.