Hardware Design Considerations for 30 kW, SiC based High-Fundamental frequency (2 kHz) Inverter for High-Speed Drives

Abstract

This paper examines the design considerations for high fundamental frequency (HFF) inverter used in high-speed (HS) drive applications, specifically focusing on a 30 kW, 2 kHz silicon carbide (SiC) based inverter. It features a 2-level, 3-phase voltage source inverter with a forced air-cooling system for effective thermal management. The DC bus voltage is set at 700 V. Unlike traditional inverters that typically operate at frequencies of 50-60 Hz for high-power applications, this inverter is designed to operate at a fundamental frequency (fo) of 2000 Hz, enabling it to drive high-speed motors exceeding 100 krpm. It evaluates SiC MOSFETs and IGBTs, highlighting SiC MOSFET better efficiency and thermal performance. The study details the inverter design, including thermal simulations, cooling system optimization, and experimental validation, demonstrating the feasibility of achieving high efficiency (>99%) and stable operation at HFF frequencies. The performance of the inverter was verified with measurements carried out on a 30 kW prototype.