What are Power Capacitors?

Power capacitors are energy storage components designed for high-current and high-voltage applications in power electronic systems. They store electrical energy in an electric field between conductive plates separated by a dielectric material, and release it as required to support voltage stability, filtering, or pulse power delivery. Their construction, dielectric type, and internal geometry are optimized to handle significant electrical stress while maintaining predictable electrical characteristics.

In applications such as DC link stabilization, harmonic filtering, snubber networks, and reactive power compensation, power capacitors play a critical role in controlling voltage ripple, transient response, and power factor. Electrical performance is governed by parameters such as capacitance value, voltage capability, current handling, and internal losses. Proper selection based on defined specifications ensures thermal stability, long service life, and reliable operation under demanding load conditions.

Key Specifications

• Type: Identifies the construction and intended application of the capacitor, such as film, electrolytic, ceramic, or other specialized designs. The type determines dielectric properties, frequency behavior, thermal performance, and suitability for specific power conversion topologies.
• Phase Configuration: Defines whether the capacitor is designed for single-phase or multi-phase systems. Phase configuration determines how the capacitor is connected within the power network and influences its role in reactive power control, filtering, or DC link stabilization.
• Capacitance: Specifies the nominal ability of the capacitor to store electric charge. Capacitance directly impacts ripple voltage, energy storage capability, and dynamic response in filtering and power conditioning applications.
• Tolerance: Indicates the permissible deviation of the actual capacitance from its nominal value. Tolerance affects accuracy in resonance tuning, harmonic filtering, and timing-sensitive circuits within power electronic systems.
• Voltage Rating: Represents the maximum continuous voltage the capacitor can withstand without dielectric breakdown or accelerated aging. Voltage rating must align with system operating conditions, including steady-state and transient voltages.
• Peak Current: Defines the maximum instantaneous current the capacitor can handle during transient or pulsed operation. This parameter is critical in applications involving high inrush currents, switching transients, or pulsed power delivery.
• Equivalent Series Resistance (ESR): Represents the internal resistive component of the capacitor that causes power dissipation and heating under AC or ripple current conditions. Lower ESR reduces conduction losses and improves efficiency and thermal performance in high-frequency and high-current applications.

The Largest Database of Power Capacitors

everything PE has listed Power Capacitors from the leading manufacturers and made them searchable by specification. You can enter the key parameters and the search tool will scan catalogs from the leading manufacturers to identify products that meet your spec. Once you find Power Capacitors that meet your requirements, you can view product information, download datasheets or request quotations. Quotation requests will be routed to the manufacturer of the product who will get back to you directly. The quotation will also be routed to distributors of the product in your region.