As the global energy structure transitions towards decarbonization and renewable energy, Battery Energy Storage Systems (BESS) have become a key technology for driving renewable energy applications, enhancing grid stability, and promoting sustainable energy development. Against this backdrop, capacitors, as essential auxiliary components in BESS, play an indispensable role in system efficiency and reliability through their outstanding performance in power management, filtering, power buffering, and voltage stabilization. In particular, the rapid development of new capacitor technologies, such as polymer capacitors and film capacitors, has not only improved durability and performance but also expanded their potential in energy storage applications. This article explores the multiple applications of new capacitors in BESS and highlights the functional features of advanced capacitors introduced by KEMET, a subsidiary of YAGEO.
Capacitors manage power and filter to ensure voltage stability
Capacitors play an important auxiliary role in BESS. The main functions of capacitors are power management and filtering. Capacitors can filter out high-frequency interference and noise during the battery charging and discharging process, ensuring system voltage stability. In inverters and rectifiers, capacitors can smooth waveforms and reduce harmonic distortion. Additionally, capacitors can handle transient responses and power buffering. When the load suddenly increases or decreases, capacitors provide transient current buffering, preventing the battery from suffering excessive current shocks and extending battery life.
On the other hand, capacitors can store and redistribute energy. In some applications, capacitors can temporarily store small amounts of energy to assist the battery in redistributing energy when power demands fluctuate. Furthermore, capacitors can assist in voltage stabilization and protection, helping to stabilize the DC link voltage within the BESS and absorbing sudden voltage spikes to protect sensitive components within the system.
According to the characteristics of battery energy storage systems, different types of capacitors are suitable for various application scenarios. For example, electrolytic capacitors, with high capacitance values and relatively low costs, can be applied to voltage stabilization in DC links, suitable for handling high currents and low-frequency filtering. However, they have a shorter lifespan and are susceptible to high temperatures. Film capacitors, with high reliability, long lifespan, high-temperature and high-voltage resistance, and low equivalent series resistance (ESR), can be used in high-frequency filtering, inverters, and circuit stabilization in power modules, although they have relatively low capacitance values and may be larger in size.
Ceramic capacitors, with excellent high-frequency characteristics, small size, high-temperature resistance, and long lifespan, can be applied in high-frequency filtering and pulse current absorption, although their capacitance values are relatively low, making them suitable for auxiliary circuits. Double-layer capacitors (supercapacitors), with high power density, fast charging and discharging capabilities, and long lifespan, can be used for transient energy storage and release, assisting batteries in meeting power peak demands, though they have low energy density and higher costs.
When selecting capacitors, priority should be given to capacity and voltage ratings. It is necessary to choose capacitors that meet the system's operating voltage and power requirements to avoid overvoltage or insufficient capacity. Furthermore, lifespan and reliability should be considered, prioritizing capacitor types with long lifespan and high stability, such as film capacitors and ceramic capacitors.
Additionally, the environmental adaptability of capacitors needs to be taken into account. Considering the high temperature, humidity, and other environmental factors that energy storage systems may face, capacitors with good weather resistance should be selected. Naturally, cost-performance balance should also be pursued, selecting capacitors with suitable performance according to application requirements to avoid overdesign and unnecessary cost increases.
Polymer capacitors feature high volumetric efficiency and capacitance stability
Polymer capacitors have multiple technical advantages, including high volumetric efficiency, long lifespan, capacitance stability, safety, and support for piezoelectric effects. They employ mechanical structures, meet aerospace considerations, support derating and DC/DC conversion, and can reduce ripple generation.
KEMET is a market leader in polymer capacitor technology. KEMET's organic capacitors are solid electrolytic devices constructed with a conductive polymer cathode, capable of delivering optimized performance across a wide range of applications. KEMET's product portfolio combines extremely low ESR with improved high-frequency capacitance retention and offers a wide range of size options, supporting designers through innovation and technology.
KEMET offers a variety of polymer capacitor types, including SMD chip type, SMD can type, radial type, stacked chip type, axial type, radial assembly type, horizontal crown SMD type, radial crown type, rectangular type, and vertical crown SMD type. With a complete range of specifications, they can meet the diverse needs of battery energy storage systems.
Safety-certified film capacitors support EMI suppression
Safety-certified capacitors are certified for safe use in AC line filtering applications to suppress interference. KEMET has introduced safety-certified film capacitors, specifically designed for attenuation of conducted emissions in AC line filtering applications. The self-healing capability of film capacitors makes them an excellent choice for power line safety, and they hold internationally recognized safety certifications. These capacitors are ideal for applications where potential disruptive or damaging line transients and EMI need to be isolated from susceptible equipment.
Film capacitors that support EMI suppression deliver reliable performance for renewable energy applications. Capacitors introduced by KEMET are meticulously designed to provide robust EMI suppression while meeting the growing demands for miniaturization and high current capability. Whether in the solar or wind energy markets, KEMET's capacitors offer exceptional performance, ensuring that renewable energy systems operate smoothly and efficiently even in harsh environments.
KEMET film capacitors feature low ESR, resulting in higher ripple current ratings without sacrificing capacitance. The high voltage rating of film capacitors makes them particularly suitable for DC link and high-power applications, while the combination of low ESR, efficient CV (capacitance/voltage), and high voltage ratings makes them ideal for energy storage and EMI filtering.
KEMET's EMI suppression film capacitors are specifically designed to handle high currents with ease, ensuring stable and reliable performance even in demanding power applications. This high current capability makes them an ideal choice for protecting sensitive electronic devices from destructive interference. Furthermore, KEMET capacitors offer a wide range of capacitance values, allowing customers to flexibly select the right solution for their specific applications. From small to large capacitances, KEMET's products can be customized to meet the specific requirements of customers.
Additionally, KEMET capacitors offer THB-grade environmental performance, capable of withstanding the toughest conditions. This means they have undergone temperature-humidity-bias testing. They reliably operate in extreme environments, including high temperatures and humidity, ensuring system protection under any conditions. Furthermore, as electronic device sizes continue to shrink, KEMET's EMI suppression film capacitors are designed with miniaturization in mind. Despite their compact form, they deliver powerful performance, enabling customers to save space without compromising quality.
DC-link film capacitors designed to drive sustainability and green technology
KEMET's DC-link film capacitors are next-generation energy-efficient components designed to drive the future of sustainability and green technology. These capacitors set a new standard of innovation by combining top-tier performance with environmentally friendly design to meet the demands of today's advanced electronic applications. Power Box film capacitors are engineered to minimize environmental impact while delivering exceptional efficiency, making them the ideal choice for projects prioritizing cutting-edge technology and sustainability.
KEMET's DC-link film capacitors feature high capacitance density, maximizing energy storage in minimal space. With exceptional capacitance density, KEMET capacitors are perfect for compact, high-performance applications. Additionally, KEMET's DC-link film capacitors are highly reliable, designed with longevity in mind to ensure consistent performance over an extended lifespan, thereby reducing the need for frequent replacements and minimizing waste.
KEMET's DC-link film capacitors are ultra-thin and lightweight, providing design flexibility through low-profile capacitors. They are ideal for space-constrained applications without compromising power. Furthermore, KEMET's low-profile capacitors offer performance capable of withstanding harsh environments. These capacitors are designed to endure the most demanding conditions, maintaining optimal functionality even in adverse settings and ensuring reliability in the toughest applications.
In addition, KEMET introduces Power Cans to power the future with sustainable technology. KEMET understands the challenges customers face in energy storage solutions, including durability, efficiency, and environmental impact. KEMET's Power Cans are specifically designed to address these pain points, offering a sustainable alternative without compromising performance.
KEMET's Power Cans feature high capacitance density, maximizing energy storage without affecting space. With outstanding capacitance density, KEMET's Power Cans provide compact yet powerful energy solutions. Additionally, KEMET's Power Cans offer high current capabilities, enabling unparalleled power transmission with high current capacity, ensuring smooth and efficient operation even under heavy loads.
KEMET's Power Cans incorporate self-healing technology, prioritizing safety and reliability. This innovative technology ensures durability and continuous operation, minimizing the risk of failure. Furthermore, KEMET's Power Cans are designed to withstand harsh environments, including extreme temperatures, humidity, and dust. With premium sealing and robust construction, KEMET's Power Cans endure the toughest conditions.
KEMET's film capacitors come in a wide variety of specifications, including radial type, can type, SMD chip type, axial type, door knob type, and dual-in-line type, offering a comprehensive range to meet the diverse needs of battery energy storage systems.
Conclusion
The development of new capacitor technologies brings unprecedented possibilities for enhancing battery energy storage system performance. With their high reliability, long lifespan, fast response, and outstanding power handling capabilities, new capacitor technologies—particularly polymer capacitors and film capacitors—play an indispensable role in energy management, voltage stabilization, filtering, and power buffering. As energy storage technologies continue to advance, these new capacitors will play a key role in achieving higher power density, handling more complex scenarios, and operating in harsher environments. A variety of new capacitors launched by YAGEO/KEMET will drive the low-carbon transformation of the global energy structure, promoting the widespread adoption of renewable energy and advancing energy sustainability.
