Inserting a supercapacitor into a complex system
Ultracapacitors and power electronic systems

Any form of energy other than electrical energy that can be recovered can be immediately stored in a supercapacitor, provided it is used in appropriate control, acting via power converters operating at low switching frequencies $\left(f⩽1\text{kHz}\right)$ .

The result is a significant improvement on many systems already using energy storage.

In this way, the supercapacitor enables rapid recharging during braking, and ensures partial but real recovery of the potential or kinetic energy of a moving mass, even over short periods.