Design and Integration of a SiC-Based High-Density All-in-One Half-Bridge PCB with Paralleled Discrete Devices for Traction Drive Applications

The demand for high-power high-density traction inverters has surged with the rapid development of electric vehicles (EVs). By employing silicon carbide (SiC) devices, traction inverters can achieve outstanding performances in power and efficiency. However, most inverter designs in both commercial EVs and academic literature suffer from excessive components, including multiple printed circuit boards (PCB), transition pieces, mechanical parts, or cables, resulting in poor system-level integration despite the use of advanced devices. To overcome this challenge of poor integration, this paper proposes a “single-board” systematic integration strategy aimed at maximizing power density while qualifying performances. Moreover, an all-in-one half-bridge (HB) PCB is designed to demonstrate the proposed integration strategy, achieving a power density of 101.7 kW/L by integrating dc and ac busbars, power devices, dc-link capacitors, gate driving components, ac current sensor, cold plate, and space for controller stage into a single PCB. Additionally, a 200 kW three-phase inverter assembly with all-in-one HB PCBs and designed enclosure is demonstrated, featuring compact, no need for additional busbars or mechanical components, and simple assembling process, thereby reducing weight and facilitating robotic manufacturing. The feasibility of the designed inverter is verified by experimental results, including tests on current sharing, insulation design, protection functions, current sensing, full-power operation, and thermal performance.