High Power Density SiC-Based Inverter with a Power Density of 70kW/liter or 50kW/kg

Abstract

This paper presents a high power density silicon carbide (SiC)-based inverter, with a two-level voltage-source structure having forced air cooling, which provides a high volumetric power density of 70 kW/liter or 50 kW/kg in gravimetric terms. In order to achieve a power density greater than that of conventional inverters, the losses must be reduced or the cooling performance must be improved. Small lightweight SiC MOSFET power modules with directly soldered foil fins having good thermal conductivities, are developed in this study. The antiparallel SiC Schottky barrier diodes (SBDs) are removed from the modules to improve the power density. Gate drivers are developed to reduce the switching losses and switching time. A prototype of the proposed high power density inverter, which includes the developed power modules and proposed gate driver, is fabricated. The volume and weight of the prototype inverter are approximately 0.5 liter and 660 g, respectively. Experimental results confirm that the prototype inverter can operate continuously with an output power up to 35 kW. Therefore, the power density of the prototype inverter is approximately 70 kW/liter or 50 kW/kg. The efficiency of the prototype inverter is found to be more than 98%. Hence, the measures undertaken in this study have been verified to improve the power density of the inverters. The proposed high power density inverters can be applied in future aircraft and other electric vehicles.

Gate Drive Circuit Implementation for Parallel Connection of Power Devices Considering Parasitic Inductance

“…Recently, power conditioners based on power converter circuits have been used in photovoltaic [4] and wind power generation [5]. In recent years, SiC power devices are expected to be applied to power converter circuits for the purpose of miniaturization and low loss [6], [7], and research and development of SiC power devices has been actively promoted. The basic performance of SiC power devices has already been reported in many papers, and it has been confirmed that SiC power devices have very excellent performances compared with Si power devices [8]- [12].…”

Design a Continuous Switching Test Circuit for Power Devices to Evaluate Reliability

“…Silicon carbide (SiC) exhibits a dielectric breakdown strength that is approximately 10 times greater than that of Si, which is conventionally used in power devices (1)∼ (9) . Owing to their features, SiC metal-oxide-semiconductor fieldeffect transistors (MOSFETs) are required for practical use in various applications (10)∼ (12) . However, long-term reliability issues in SiC MOSFETs, such as bias temperature instability (BTI), have been reported (13)∼ (15) .…”

High power density inverter utilizing SiC MOSFET and interstitial via hole PCB for motor drive system

“…Power electronics using SiC and other wide bandgap (WBG) devices promises further miniaturization and loss reduction; particular attention is paid to smaller size, lighter weight, and higher fuel efficiency due to higher density of automotive electronics and avionics 1–11 . There are many reports on development of high‐density power electronics; as regards motor drive systems, there are reports on water‐cooled systems for automotive applications 1–4 and forced air‐cooled systems for industrial applications 5–11 . In the water‐cooled vehicle‐mounted systems, there are schemes of two‐sided cooling of power semiconductors, 1–4 water‐cooling fins being integrated on the bottom surface of power modules ion some systems 2 ; there are implementation examples with power density above 100 kVA/L 3,4 .…”

“…Power electronics using SiC and other wide bandgap (WBG) devices promises further miniaturization and loss reduction; particular attention is paid to smaller size, lighter weight, and higher fuel efficiency due to higher density of automotive electronics and avionics 1–11 . There are many reports on development of high‐density power electronics; as regards motor drive systems, there are reports on water‐cooled systems for automotive applications 1–4 and forced air‐cooled systems for industrial applications 5–11 .…”

“…In the water‐cooled vehicle‐mounted systems, there are schemes of two‐sided cooling of power semiconductors, 1–4 water‐cooling fins being integrated on the bottom surface of power modules ion some systems 2 ; there are implementation examples with power density above 100 kVA/L 3,4 . As regards the forced air‐cooled systems for industrial applications, the highest power density achieved so far is 70 kW/L with one‐sided cooling 6 …”