What happens to the energy stored in an inductor when it is discharged after it reaches steady state?
In transient state analysis, the voltage in the inductor changes its polarity when discharged and opposes change in current.
What happens when the inductor is discharged from steady state as voltage is 0?
What happens to energy stored in inductor when it is discharged after it reaches steady state
An ideal inductor (zero resistance) that is discharged by a zero resistance path (a short circuit) will maintain the energy in the inductor until the end of time. Of course, this means that the inductor current continues to flow and, does not change value from the charge current acquired at the point when discharging occurs.
For a real-world inductor with non-zero series resistance, the continuous flow of a discharge current means \$I^2R\$ losses and, this reduces the initial energy stored until it depletes to zero (and zero current).
For an inductor, \$V=L\frac{di}{dt}\$, meaning that even if the voltage started at zero, cutting off the current suddenly produces a very large voltage spike.
Circuits that use PWM to control inductors, like motor speed controls, should contain a snubbing diode to protect other circuit elements.
