[Selection Guide] How to Balance High Voltage and Long Life in Miniaturized OBCs? Analysis of YMIN LKD High-Voltage Capacitors

[Selection Guide] How to Balance High Voltage and Long Life in Miniaturized OBCs? Analysis of YMIN LKD High-Voltage Capacitors

Introduction

In 800V OBC and DC-DC designs, capacitor selection has become a key factor affecting power density, efficiency, and reliability. Traditional aluminum electrolytic capacitors, due to their large size, short lifespan, and poor high-frequency characteristics, cannot meet these requirements. This article will analyze the performance advantages of YMIN Electronics’ LKD series high-voltage aluminum electrolytic capacitors in terms of miniaturization, high ripple current resistance, and long lifespan, providing engineers with a selection guide.

OBC – YMIN Aluminum Electrolytic Capacitor LKD Solution

With the prevalence of SiC devices and increasing switching frequencies, capacitors in OBC modules must withstand higher ripple currents and thermal stresses. Conventional aluminum electrolytic capacitors are prone to overheating and have a short lifespan. Achieving high capacitance, high voltage resistance, low ESR, and long life in a compact size has become a core pain point in OBC design.

- Root Cause Technical Analysis -

The root cause of the problem lies in the material and process limitations of traditional capacitors:

Ordinary electrolytes are easily volatile at high temperatures, leading to capacitance fading and increased ESR;

Conventional structural designs have low capacitance density, making it difficult to balance high voltage and capacitance;

Inadequate sealing reliability leads to leakage in vibration environments.

Key parameters such as capacitance density, ESR @ 100kHz, rated ripple current @ 105°C, and lifespan directly impact system success.

- YMIN Solutions and Process Advantages -

The YMIN LKD series utilizes several innovative processes:

1. High-density electrode foil: Increases capacitance per unit volume, reducing the volume by 20% to 40% compared to similar products;

2. Low-impedance electrolyte: Effectively reduces ESR and improves high-frequency ripple tolerance;

3. Reinforced sealing and explosion-proof structure: Passes 10G vibration resistance testing, eliminating leakage risks;

4. High-voltage redundancy design: Provides ample voltage margin, suitable for applications on platforms of 800V and above.

Reliability Data Verification & Selection Recommendations

As can be seen, the LKD series significantly outperforms conventional products in terms of size, ESR, ripple resistance, and lifespan.

- Application Scenarios and Recommended Models – The LKD series is suitable for: OBC PFC boost circuit output filtering; DC-Link support and buffering; and DC-DC filtering.

- Recommended Models -

LKD 700V 150μF 25×50: Suitable for 1200V DC-Link systems;

LKD 500V 330μF 25×50: Suitable for high-capacity filtering in 800V systems;

LKD 450V 330μF: Balances size and capacity requirements;

LKD 500V 220μF: Suitable for use in extremely space-constrained applications.

Conclusion

YMIN’s LKD series, through innovative materials and structures, successfully addresses the reliability and compact size requirements of capacitors in high-voltage, high-frequency, and high-temperature applications. It has become the capacitor of choice for OBC projects at many leading automotive companies. We support sample applications and technical support, helping engineers quickly implement projects.