Energies and powers (electric system)


This section deals with the stored energy and the power dissipated in an electric system.

Power: definition (reminder)

The instantaneous power consumed by a system with respect to two terminals (dipole) is equal to the product of the instantaneous values of the current I which passes through it and the voltage U at its terminals, respectively:


Stored energy

The components that allow the storage of energy are the coils and the capacitors. The energy storage can be a temporary given that the stored energy can be then transferred via a current to the circuit that contains the component.

Component Stored energy

A coil of inductance L stores energy as magnetic energy.

A capacitor of capacitance C stores energy as electric energy.

Dissipated power / Power losses by Joule effect

The components that dissipate energy are the resistive electric components (resistor / brush-segment / switch / diode).