Performance improvement of SiC based High Power Inverters by using film capacitor bank vs traditional electrolyte or polymer capacitors

Abstract

Abstract: This paper investigates the performance enhancement of Silicon Carbide (SiC) based high-power inverters through the integration of film capacitor banks as compared to traditional electrolytic or polymer capacitors. SiC-based inverters have gained significant attention due to their superior efficiency, high-temperature tolerance, and faster switching capabilities, particularly at high Pulse Width Modulation (PWM) carrier frequencies. The study explores the impact of capacitor selection on key inverter performance metrics, including Electromagnetic Interference (EMI), Electromagnetic Compatibility (EMC), ripple current, and thermal behavior. The unique characteristics of film capacitors—such as lower equivalent series resistance (ESR) and higher thermal stability—are highlighted, providing advantages in high-frequency switching applications. In this study, experimental setups are designed to test high-frequency PWM operation (up to 100 kHz) in SiC inverters using both film capacitors and traditional electrolytic or polymer capacitors. Results indicate that the film capacitor bank offers significant reductions in ripple current and EMI, thereby improving overall system efficiency and reducing losses. The film capacitors also demonstrate a more stable thermal performance under high-frequency operation, whereas the traditional capacitors exhibit increased ESR and thermal dissipation, potentially limiting their operational lifespan in high-power applications.