Technical Deep Dive | How Can DC-Link Film Capacitors Address Voltage Surge and Reliability Challenges in 800V Electric Drive Platforms?

Introduction

As 800V high-voltage platforms become mainstream in new energy vehicles, electric drive inverters are placing higher demands on the high-frequency characteristics of DC-Link capacitors. Traditional aluminum electrolytic capacitors, limited by their high ESR and frequency response, are prone to voltage surges, limiting system efficiency and hindering the full performance of SiC devices.

Schematic diagram of the location of the DC-Link capacitor in the inverter

YMIN Film Capacitor Solutions

- Root Cause Technical Analysis – Due to their material and structural characteristics, aluminum electrolytic capacitors typically have high ESR and low self-resonant frequency (typically only around 4kHz). Under high-frequency switching operations, their ability to absorb high-frequency ripple current is insufficient, easily causing bus voltage fluctuations, which in turn affects system stability and power device life. – YMIN Solutions and Process Advantages – YMIN’s MDP series film capacitors utilize metallized polypropylene film material and an innovative winding process to achieve the following performance improvements: ESR is reduced to the milliohm level, significantly reducing switching losses; the resonant frequency is increased to tens of kHz, fully adapting to the high-frequency application requirements of SiC/MOSFETs; and their advantages include high withstand voltage, low leakage current, and long life, making them particularly suitable for high-voltage, high-frequency operating environments.

- Data Verification and Reliability Explanation -

Application Scenarios and Recommended Models -

Typical Application Case: A major automaker’s 800V electric drive platform uses eight MDP-800V-15μF capacitors in the DC-Link circuit of the main drive inverter, successfully replacing the original solution’s 22 450V aluminum electrolytic capacitors. This reduces PCB area by over 50%, reduces bus voltage peak by 40%, and improves system peak efficiency by approximately 1.5%. – Recommended Models -

Conclusion
The YMIN MDP series is not only a high-performance capacitor but also a key voltage regulator in high-voltage, high-frequency systems. It can help engineers fundamentally address design challenges and comprehensively improve system performance and reliability.