A hybrid modulation scheme for cascaded h-bridge inverter cells

Thesis Abstract

Abstract
This research proposes a novel hybrid modulation scheme for cascaded H-bridge inverter cells. Cascaded H-bridge inverters have gained popularity in medium to high-power applications due to their scalability and flexibility. However, traditional modulation techniques such as space vector modulation (SVM) or carrier-based pulse width modulation (PWM) have limitations when applied to cascaded configurations. The proposed hybrid modulation scheme combines the advantages of both SVM and PWM techniques to address the challenges in cascaded H-bridge inverters. By intelligently switching between SVM and PWM based on the operating conditions, the proposed scheme optimizes the performance of the inverter system. The SVM component ensures high-quality output voltage waveform with reduced total harmonic distortion (THD), while the PWM component enhances the efficiency of the modulation process. Simulation results demonstrate the effectiveness of the hybrid modulation scheme in improving the overall performance of cascaded H-bridge inverters. The scheme successfully minimizes THD levels, enhances the output voltage quality, and reduces switching losses compared to conventional modulation techniques. Moreover, the proposed scheme offers better utilization of the available DC voltage sources, leading to improved efficiency and reliability of the inverter system. Furthermore, the hybrid modulation scheme provides flexibility in adapting to different load conditions and system requirements. By dynamically adjusting the modulation strategy based on the operating conditions, the inverter can maintain optimal performance across a wide range of load variations. This adaptability is crucial for applications with fluctuating load demands or varying grid conditions. In conclusion, the hybrid modulation scheme presents a promising solution for enhancing the performance of cascaded H-bridge inverters. By leveraging the strengths of both SVM and PWM techniques, the proposed scheme achieves improved efficiency, reduced THD, and enhanced output quality. Future research may focus on hardware implementation and experimental validation to validate the effectiveness of the hybrid modulation scheme in practical applications.Overall, the proposed hybrid modulation scheme has the potential to advance the capabilities of cascaded H-bridge inverters and enable their widespread adoption in medium to high-power systems.