Electrical Power Systems Technology

Power System Fundamentals 33

Sample Problem: Energy Stored in an Inductor

A coil stores energy in its magnetic field because of current flow

through it. The amount of energy is defined by the equation:

1

W + — × L × I^2 , where

2

W = energy stored in joules

L = coil inductance in henries

I = current flow through the coil in amperes

Figure 2-10. Resistive circuit: (A) Circuit diagram; (B) Waveforms; (C) Vector

representation