A Practical Use of xEVCap: The Modular and Standard DC-Link Capacitor Solution for the Main EV Powertrain Inverter

Abstract:
An innovative DC-link capacitor solution [1] for the main xEV powertrain Inverter has been presented to the market as of July 2024. The innovation is sustained by the conjunction of four pillars: modularity and scalability; design for application; design for manufacturing; and standardization (catalog product). After a brief review of these pillars already detailed in [1], this paper focuses on the practical study of xEVCap at the system level. The analysis is deployed in four major subject areas. The parasitics (ESL, ESR, …) from the single capacitor element to the effective ones at the system level. The second area is the assembly and joint technologies with the busbar. The third area is the strategy for thermal decoupling between the capacitor and power semiconductors without a cooler. The paper concludes with the thermal integration with a cooler and how the various elements interact under different temperatures. Everything is supported by Ansys and CFD simulations and with the construction of a demonstrator for laboratory testing. This paper also presents the results of collaboration with recognized external partners, like power-semiconductor and busbar suppliers.