Energy Stored in an Inductor
We start from the definition of voltage: V = PE/q (or PE = qV). But since the voltage across an inductor is related to the current change, we might express q in terms of I:
I = dq/dt, or dq = I dt. Therefore, we have:
Estored = S qi Vi = ? V dq = ? V I dt and now we use VL = L dI/dt to get:
Estored = ? (L dI/dt) I dt = ? L I dI = (1/2)LI2.