The new energy vehicle industry is rapidly developing towards high-power fast charging, bidirectional charging and discharging, and high system integration. On-board chargers (OBCs), as core charging components, are undergoing a wave of technological upgrades. High-voltage electrical systems are evolving from the mainstream 800V architecture to a higher-end 1200V version. The construction of high-voltage platforms has become the core foundation for achieving ultra-fast charging, and it also places higher performance requirements on core components such as capacitors.

01 What important role do capacitors play in on-board OBCs?

In the high-voltage battery system of new energy vehicles, capacitors are the core energy storage and filtering components of the on-board OBC and DC-DC converter. Their performance directly determines the energy conversion efficiency, power density, and long-term operational reliability of the power conversion system. In on-board scenarios, high-voltage platforms often face complex conditions such as instantaneous voltage surges and high-frequency power fluctuations. Coupled with the bidirectional energy flow conditions brought about by bidirectional charging and discharging, capacitors must operate stably and continuously in the harsh on-board environment of high voltage, high frequency, and high temperature. At the same time, the filtering performance of capacitors directly affects the electromagnetic compatibility compliance of the entire vehicle and is a key factor in ensuring that the OBC passes the national mandatory EMC certification. Therefore, selecting capacitors with high voltage resistance, high capacitance density, and low parasitic parameters is a core factor determining the overall performance of automotive OBCs.

02 What are the application advantages of YMIN capacitors?

Addressing the stringent technical requirements of OBC & DC-DC converters in high-voltage systems for capacitors with high voltage resistance, miniaturization, long lifespan, and high ripple current tolerance, YMIN leverages technological innovation and structural optimization in three core materials—aluminum foil, electrolyte, and electrolytic paper—to create a comprehensive matrix of high-performance capacitors. This matrix comprehensively empowers the performance upgrade and reliability improvement of OBC & DC-DC systems in new energy vehicles, while also helping customers optimize their supply chains and achieve domestic substitution.

Liquid Horn-Shaped Aluminum Electrolytic Capacitors: "Voltage Stabilizers" for High-Power Applications

Yongming's CW3H series liquid horn-shaped aluminum electrolytic capacitors, thanks to core material innovation and process optimization, have become a core voltage regulator component for high-power automotive OBC applications, providing robust protection for DC-Link applications on 800V and above high-voltage platforms:

High Voltage Withstand and Surge Resistance: Addressing the frequent voltage fluctuations and spikes encountered during OBC operation, the capacitors feature a design with ample voltage margin and high-purity etched aluminum foil, providing strong voltage support and reliable overvoltage protection. Each capacitor undergoes rigorous testing before leaving the factory, including high-voltage aging and full-load durability tests, ensuring long-term stability in automotive applications.

High Ripple Current Withstand: Equipped with a low-impedance, low-temperature resistant innovative electrolyte, effectively reducing ESR values. Under the surge current generated by OBC power conversion, even with an applied ripple current of 1.3 times the rated current, the temperature rise remains stable, and product performance remains stable, perfectly adapting to frequent power conversion conditions.

High Capacity Density and Space Saving: Utilizing a self-developed special riveting and winding process, the internal structure is optimized, resulting in 20% higher capacity than the industry average for the same volume. It also boasts a smaller size for the same voltage and capacity, significantly saving installation space in automotive equipment and aligning with the trend of miniaturization in overall design.

Liquid-Packed Aluminum Electrolytic Capacitors: "Performance Breakthrough" in High-Temperature, Compact Spaces

Yongming LKD series liquid-packed aluminum electrolytic capacitors are specifically designed for automotive OBCs where size limitations prevent the use of horn-shaped capacitors. They are ideal for achieving efficient filtering and reliable energy storage in harsh high-voltage, high-frequency environments, with significant core advantages:

High Temperature Resistance for Harsh Environments: Achieving a continuous operating temperature of 105℃ within a compact package structure, far exceeding the industry average of 85℃, providing stable performance assurance for high-temperature, sealed automotive applications.

Extremely Miniaturized with High Capacity: Under the same voltage, capacity, and specifications, the LKD series is 20% smaller in diameter and height than the horn-shaped product. If the height remains the same, the diameter can be further reduced by 40%, perfectly fitting the limited installation space of automotive OBCs.

Superior Performance, High Sealing, and Long Lifespan: Utilizing a high-temperature resistant structural design, it significantly reduces ESR and possesses strong ripple current resistance. Combined with self-developed unique sealing materials and encapsulation technology, its airtightness is superior to horn-shaped capacitors, effectively extending its service life. It can meet the long-term operating requirements of 12,000 hours at 105℃, matching the full lifespan requirements of the vehicle.

Solid-Liquid Hybrid Capacitors: A Two-Way Bridge Between High Efficiency and Stability

Yongming's VHT/VHU series solid-liquid hybrid capacitors combine the technological advantages of solid and liquid capacitors. Utilizing a polymer hybrid dielectric, they fundamentally solve the industry-wide problem of abnormal leakage current after high-temperature reflow soldering of traditional capacitors, becoming a "two-way bridge" for efficient energy conversion and stable operation in automotive OBCs:

High Capacitance Density and Strong Stability: Compared to capacitors of the same volume on the market, the capacitance is increased by more than 30%, and capacitance fluctuations are precisely controlled within ±5% over a wide temperature range. Even after long-term operation, the capacitance remains stable at over 90% of its initial value. Tests on 100 batches of samples show almost no performance drift after reflow soldering, ensuring long-term system stability.

Extremely low leakage current, low ESR, and excellent consistency: Leakage current is precisely controlled below 20μA, with a measured average of only 3.88μA; ESR is controlled below 8mΩ, and excellent consistency is observed between batches and products. Even after a 260℃ high-temperature reflow soldering process, ESR and leakage current remain stable with no significant drift, perfectly meeting the requirements of automotive electronic surface mount technology (SMT) processes, while effectively reducing overall power consumption.

Film Capacitors: A Long-Life, High-Reliability "Safety Barrier"

Compared to traditional electrolytic capacitors, Yongming MDP series metallized polypropylene film capacitors offer significant technological advantages in voltage withstand, stability, and lifespan. Their low parasitic inductance results in excellent high-frequency filtering, making them a "safety barrier" in the harsh environment of automotive OBCs, while also simplifying system design:

Ultra-High Voltage Withstand without Series Connection: Withstanding over 1200V, they can be adapted to 1200V high-voltage platforms without series connection. They can withstand voltage surges of 1.5 times the rated operating voltage, exhibiting excellent voltage adaptability and surge resistance, perfectly matching the upgrade requirements of high-voltage platforms.

Superior Ripple Tolerance: With a ripple tolerance of 3μF/A, more than 50 times that of traditional electrolytic capacitors, they easily handle ripple surges caused by high-frequency power fluctuations in automotive OBCs, effectively suppressing harmonic interference and helping OBCs meet the high-level electromagnetic compatibility limits of GB/T 18487.1 CLASS 3.

Ultra-long lifespan with no expiration date: Achieving an ultra-long lifespan of over 100,000 hours at 105℃, the dry-packing design eliminates any shelf-life limitations. Under the same automotive operating conditions, it maintains core performance for a longer period, significantly reducing system maintenance costs and meeting the full lifecycle needs of the vehicle.

In the future, YMIN will continue to focus on the high-voltage and integrated development trends of new energy vehicles, deeply cultivating R&D and innovation in core capacitor materials and structural technologies. Simultaneously, it will implement a dual-track customized development strategy, providing both standard products compatible with mainstream international models and customized solutions for customers. Continuously upgrading product performance and solutions, YMIN will provide more efficient, reliable, and adaptable capacitor products and technical support for new energy vehicle OBC & DC-DC systems, contributing to the high-quality development of the new energy vehicle industry!