Q.Why the power semiconductor devices are used in power controls?

Power electronics is the area of electronics concerned with controlling and converting the flow of electrical energy rather than processing information. Ordinary electronics handles small signals; power electronics switches large voltages and currents efficiently, with almost no loss inside the device. The central idea is simple: by controlling how current flows through a power semiconductor device, we control the power delivered to the whole system built around it.

A power semiconductor device is a switching device built to survive large voltages and carry large currents while wasting as little energy as possible. An ideal power device should offer a large blocking (withstand) voltage in the OFF state, a large forward-current capability, a very low on-state voltage drop, near-zero off-state leakage, instant turn-on and turn-off, and the ability to tolerate a large rise in temperature. …