Capacitor Applications Supported by API
Updated: Sep 10
Inside every Variable Frequency Drive (VFD), capacitors perform functions that directly affect performance and reliability, and we design and manufacture capacitors for each of the roles below.
The largest and most visible are the DC bus capacitors, which smooth the rectified DC voltage. Acting as both energy storage and voltage stabilisers, they give the inverter a clean DC supply to produce precise, stable AC power for the motor.
On the input side, filter capacitors help the VFD coexist with the rest of the electrical system. Working with inductors in electromagnetic interference (EMI) filter circuits, they suppress the high-frequency noise generated by the drive, preventing interference with other equipment and allowing the VFD to meet strict compliance requirements.
Within the inverter, snubber capacitors protect sensitive switching devices such as IGBTs and MOSFETs from transient voltage spikes. By absorbing the energy of rapid switching events, they safeguard components from overvoltage stress and help reduce EMI.
We supply capacitors for all three roles, matched to the voltage, current and environmental requirements of each application, and work with customers to tailor designs where a standard part won't do.
