A good horse deserves a good saddle! To fully leverage the advantages of SiC devices, it is also necessary to pair the circuit system with suitable capacitors. From the main drive control in electric vehicles to high-power new energy scenarios like photovoltaic inverters, film capacitors are gradually becoming mainstream, and the market urgently needs high-cost-performance products.
Recently, Shanghai Yongming Electronic Co., Ltd. launched DC support film capacitors, which have four outstanding advantages making them suitable for Infineon’s seventh-generation IGBTs. They also help address the challenges of stability, reliability, miniaturization, and cost in SiC systems.
Film capacitors achieve nearly 90% penetration in main drive applications. Why do SiC and IGBT need them?
In recent years, with the rapid development of new energy industries such as energy storage, charging, and electric vehicles (EVs), the demand for DC-Link capacitors has been increasing rapidly. Simply put, DC-Link capacitors act as buffers in circuits, absorbing high pulse currents from the bus end and smoothing bus voltage, thus protecting IGBT and SiC MOSFET switches from high pulse currents and transient voltage impacts.
Typically, aluminum electrolytic capacitors are used in DC support applications. However, with the bus voltage of new energy vehicles increasing from 400V to 800V and photovoltaic systems moving towards 1500V and even 2000V, the demand for film capacitors is rising significantly.
Data shows that in 2022, the installed capacity of electric drive inverters based on DC-Link film capacitors reached 5.1117 million units, accounting for 88.7% of the total installed capacity of electronic controls. Leading electronic control companies such as Fudi Power, Tesla, Inovance Technology, Nidec, and Wiran Power all use DC-Link film capacitors in their drive inverters, with a combined installed capacity ratio of up to 82.9%. This indicates that film capacitors have replaced electrolytic capacitors as the mainstream in the electric drive market.
This is because the maximum voltage resistance of aluminum electrolytic capacitors is approximately 630V. In high voltage and high power applications above 700V, multiple electrolytic capacitors need to be connected in series and parallel to meet the usage requirements, which brings additional energy loss, BOM cost, and reliability issues.
A research paper from the University of Malaysia indicates that electrolytic capacitors are typically used in the DC link of silicon IGBT half-bridge inverters, but voltage surges can occur due to the high equivalent series resistance (ESR) of electrolytic capacitors. Compared to silicon-based IGBT solutions, SiC MOSFETs have higher switching frequencies, resulting in higher voltage surge amplitudes in the DC link of half-bridge inverters. This can lead to device performance degradation or even damage, as the resonant frequency of electrolytic capacitors is only 4kHz, insufficient to absorb the current ripple of SiC MOSFET inverters.
Therefore, in DC applications with higher reliability requirements, such as electric drive inverters and photovoltaic inverters, film capacitors are typically chosen. Compared to aluminum electrolytic capacitors, their performance advantages include higher voltage resistance, lower ESR, no polarity, more stable performance, and longer lifespan, enabling a more reliable system design with stronger ripple resistance.
Additionally, using film capacitors in the system can repeatedly leverage the high-frequency, low-loss advantages of SiC MOSFETs, significantly reducing the size and weight of passive components (inductors, transformers, capacitors) in the system. According to Wolfspeed research, a 10kW silicon-based IGBT inverter requires 22 aluminum electrolytic capacitors, whereas a 40kW SiC inverter only needs 8 film capacitors, greatly reducing the PCB area.
YMIN Launches New Film Capacitors with Four Major Advantages to Support the New Energy Industry
To address urgent market demands, YMIN has recently launched the MDP and MDR series of DC support film capacitors. Utilizing advanced manufacturing processes and high-quality materials, these capacitors are perfectly compatible with the operating requirements of SiC MOSFETs and silicon-based IGBTs from global power semiconductor leaders such as Infineon.
YMIN’s MDP and MDR series film capacitors have several notable features: lower equivalent series resistance (ESR), higher rated voltage, lower leakage current, and higher temperature stability.
Firstly, YMIN’s film capacitors feature a low ESR design, effectively reducing the voltage stress during the switching of SiC MOSFETs and silicon-based IGBTs, thereby minimizing capacitor losses and improving overall system efficiency. Additionally, these capacitors have a higher rated voltage, capable of withstanding higher voltage conditions and ensuring stable system operation.
The MDP and MDR series of YMIN film capacitors offer capacitance ranges of 5uF-150uF and 50uF-3000uF, and voltage ranges of 350V-1500V and 350V-2200V, respectively.
Secondly, YMIN’s latest film capacitors have lower leakage current and higher temperature stability. In the case of electric vehicle electronic control systems, which typically have high power, the resulting heat generation can significantly affect the lifespan and reliability of film capacitors. To address this, the MDP and MDR series from YMIN incorporate high-quality materials and advanced manufacturing techniques to design an improved thermal structure for the capacitors. This ensures stable performance even in high-temperature environments, preventing capacitor value degradation or failure due to temperature rise. Furthermore, these capacitors have a longer lifespan, providing more reliable support for power electronic systems.
Thirdly, the MDP and MDR series capacitors from YMIN feature a smaller size and higher power density. For example, in 800V electric drive systems, the trend is to use SiC devices to reduce the size of capacitors and other passive components, thus promoting miniaturization of electronic controls. YMIN has employed innovative film manufacturing technology, which not only increases the overall system integration and efficiency but also reduces the system size and weight, enhancing the portability and flexibility of devices.
Overall, YMIN’s DC-Link film capacitor series offers a 30% improvement in dv/dt withstand capability and a 30% increase in lifespan compared to other film capacitors on the market. This not only provides better reliability for SiC/IGBT circuits but also offers better cost-effectiveness, overcoming the price barriers in the widespread application of film capacitors.
As an industry pioneer, YMIN has been deeply involved in the capacitor field for over 20 years. Its high-voltage capacitors have been stably applied in high-end fields such as onboard OBC, new energy charging piles, photovoltaic inverters, and industrial robots for many years. This new generation of film capacitor products solves various challenges in film capacitor production process control and equipment, has completed reliability certification with leading global enterprises, and achieved large-scale application, proving the product’s reliability to larger customers. In the future, YMIN will leverage its long-term technical accumulation to support the rapid development of the new energy industry with high-reliability and cost-effective capacitor products.
For more information, please visit www.ymin.cn.
Post time: Jul-07-2024