How to select energy storage electrolytic capacitors

What are energy storage capacitors?

Energy storage capacitors can typically be found in remote or battery powered applications. Capacitors can be used to deliver peak power, reducing depth of discharge on batteries, or provide hold-up energy for memory read/write during an unexpected shut-off.

What are aluminum Elec-trolytic capacitors used for?

One of the main application classes of aluminum elec-trolytic capacitors is input capacitors for power invert-ers. The aluminum electrolytic capacitor provides a unique value in high energy storage and low device impedance. How you go about selecting the right ca-pacitor or capacitors, however, is not a trivial matter.

How does a capacitor store energy?

Capacitors store energy in an electric field generated by this arrangement once a current is supplied to charge the capacitor. In an aluminum electrolytic capacitor, the electrodes are made out of aluminum foil. Between the two aluminum electrodes is a conductive liquid, called an electrolyte.

Why is an aluminum electrolytic capacitor a good insulator?

As an insulator, charges do not flow through its material. At the same time, it has the capacity to transfer the electric force. A major benefit to an aluminum electrolytic capacitor is that it provides ample capacitance per unit of volume for the application's voltage rating.

Are aluminum electrolytic bus capacitors a good choice for inverter power systems?

Abstract— Aluminum electrolytic capacitors are widely used in all types of inverter power systems, from variable-speed drives to welders to UPS units. This paper discusses the considerations involved in selecting the right type of aluminum electro-lytic bus capacitors for such power systems.

Can aluminum electrolytic capacitors withstand reverse voltages?

Aluminum electrolytics cannot withstand reverse voltages, even at levels ≤1.5V, continuously or repetitive operation. The useful life values stated in our datasheets apply to aluminum electrolytic capacitors with natural cooling (i.e., the heat generated in the winding is dissipated through the case).