DC-LINK film capacitors that can replace electrolytic capacitors

Electrolytic capacitors have obvious advantages, namely small size and large capacity, but their disadvantages are also very obvious. Because they contain electrolyte, which is easy to evaporate, their lifespan is very short. They cannot meet the requirements of some new energy fields that require higher stability and longer lifespan. In this case, DC-LINK capacitors can be used.

DC-LINK film capacitors

Especially in inverters, DC-Link capacitors are frequently seen. While the inverter receives pulse currents with high effective values and high peak values from the DC-Link, it also generates high pulse voltages on the DC-Link, which the inverter cannot withstand. Therefore, DC-Link capacitors need to be selected for connection. On the one hand, they absorb the high pulse current from the inverter at the DC-Link end, preventing high pulse voltages from being generated on the DC-Link impedance, and keeping the voltage fluctuations at the inverter end within an acceptable range. On the other hand, they also prevent the inverter from being affected by voltage overshoot and transient overvoltage at the DC-Link end. Electrolytic capacitors are not suitable for this situation because their lifespan is too short.

Why are people now more willing to choose DC-LINK film capacitors?

1. The cost of film capacitors has been decreasing.

Compared to previous years, the production cost of film capacitors has decreased. Although they are still more expensive than electrolytic capacitors, more and more manufacturers are choosing DC-LINK film capacitors for circuit designs that require high operating voltage, high ripple current (Irms), overvoltage requirements, reverse voltage phenomena, handling of high surge current (dV/dt), and long lifespan.

2. DC-LINK capacitors have a longer lifespan.

For example, many new energy users of Safe Electronics generally require products with a lifespan of up to 15 years. Even if you choose the best quality electrolytic capacitors, their lifespan cannot meet such high requirements, but SaiFu's DC-LINK capacitors can easily meet the requirements.

Currently, our Safe Electronics manufacturing plant uses imported Leybold coating machines from Germany. Our safety film evaporation technology allows us to produce large-capacity DC filter capacitors with voltages ranging from 450V to 1200V or even higher using ultra-thin OPP films (2.7μm, or even 2.4μm). Furthermore, by integrating DC-Link capacitors with the busbars, we have made the inverter module design more compact, significantly reducing stray inductance and optimizing the circuitry.

Therefore, the shipment volume of SaiFu's DC-LINK capacitors has been increasing rapidly. In the new energy field, they are beginning to quickly replace short-life electrolytic capacitors, making customers' products more stable and longer-lasting.