Introduction of power electronics

Power electronics belongs partly to power engineers and partly to electronics engineers. It means it is the combination of power engineering and electronics engineering.
Power engineering is mainly concerned with generation, transmission, distribution and utilization of electric energy at high efficiency.
The simple engineering is guided by distortion-less production, transmission and reception of data and signals of very low power level of the order of a few watts, or milliwatts without much consideration of the efficiency.
Power electronics is also known as industrial electronics.
The apparatus associated with power engineering is based mainly on electromagnetic principles, whereas in electronics engineering they are based on physical phenomenon in vacuum, gases/vapours and semiconductors.
This subject concerns the application of electronic-principles into situations that are rated at power levels rather than signal levels.
It may also be defined as a subject that deals with the apparatus and equipment working on the principle of electronics, but rated at power level, not at signal level.

Applications of Power electronics

Power electronics is used in space shuttle power supplies
Since there is very low loss in power electronic devices so its efficiency is very high.
Power electronic converter systems are highly reliable.
Since there is no moving parts in power electronic systems so it has long life and also its maintenance cost is very less.
The power electronic systems has fast dynamic response in comparison to electromechanical converter systems.
Since the power electronic system has small size and also it has less weight so they occupy less floor space and hence their installation cost is also less.
Now these days power equipment are being mostly used, so power semiconductor devices are being produced on a large scale, resulting in lower cost of converter equipment.
Power electronics are used in computer and office equipment.
It is used in uninterruptible power supplies.
Power electronics are used in elevators.
Power electronics is also used in light dimmers and flashers

The power electronic converter circuits have a tendency to generate harmonics in the supply system as well as in the load circuit.
AC to DC and DC to AC converters operate at a low input power factor under certain operating conditions. In order to avoid a low power factor, some special measures have to be adopted.
The overload capacity of power electronic controllers are very low.
It is very difficult to regenerate power in power electronic converter systems.

The output of a power electronic converter circuit depends on the requirement of the load.

If the load is a dc motor, then the output of converter must be an adjustable direct voltage.
If the load is a 3-phase induction motor, then the converter may have adjustable voltage and frequency at its output terminals.
In power electronic systems, the feedback component measures a parameter of the load and also compare it with the command. For example it measures the speed in case of a rotating machine.

To know about introduction of power electronics click here.