Ever wondered how 240 Volt AC supply at your home charges the 5V battery of your mobile phone, or how does the DC power from renewable sources like solar, wind supply the required AC power to cater to your domestic needs? If you study deeper into these technologies, you will unravel a circuit where electronic devices play an imperative role in making these things happen. These circuits come under the radar of power electronics, an emerging science relevant to both power engineers and electronics engineers alike.
This article aims to give you a basic idea about the fundamentals of power electronics. It also focusses on the ways this ever ushering subject is prominent in our day to day life.
Let us start by discussing the concept of power electronics and further understand its basic definition.
What is Power Electronics?
Electric energy is undoubtedly one of the imperative parts of our lives. You must have noticed that while all the appliances work on a common source, the AC mains of the house, they all have varied power demands. In order to meet these, different circuits are used where power is changed to the desired form. Like for example, your mobile phone requires a DC power of low value, so a circuit acts between the main supply of your house and the battery to change the input AC to DC while changing the voltage as well, to reach the required low voltage DC power.
 |
| Image Credit: Wikimedia Commons |
These power circuits use solid-state switching devices which are usually seen in low signal applications. There is a dedicated branch in electrical engineering that studies the application of these electronic devices in various power circuits and is known as Power electronics. It not only requires power engineering knowledge but also uses fundamentals from electronics engineering as well.
Power electronics, however, is not a new concept. It dates back to 1902 when Peter Cooper Hewitt developed a mercury arc rectifier to convert AC to DC. Now over 100 years later, power electronics has transcended into almost all the fields of electric energy and denotes a term common for all the power conversion and control circuits.
Basically, power electronic circuits use different passive and active devices like GTO, SCR, etc. These active devices work mainly as switches which help in controlling or converting electric power from one form to another. Various switching techniques like PWM, Soft switching techniques have been developed over the years which helps them to achieve the same. The power conversion and control is possible because of the variable components of electric power. As we know, electric power is the product of voltage, current, and frequency(in case of AC signal). A change in any of these or a combination of these can alter the power as well.
For example, rectifiers, which are one of the most used power electronic circuits, convert AC input power to DC power using different switching devices and passive components such as inductors, resistors, and capacitors by altering the input current from bidirectional AC to unidirectional DC.
Another example of a power electronic circuit is a buck voltage converter, where the input voltage is decreased at the load side, using a combination of solid-state switches and passive electrical components.
Now that you’ve gained an idea of what power electronics is, let us make it more interesting by making you realize how it affects your life, without you being aware of it.
Applications of power electronics in daily life:
We live in an era, where more and more technologies are emerging to explore the various ways to make the best out of renewable energy sources like solar, wind, etc. More people are encouraged to use Solar panels to meet the basic requirement of an average household to reduce the use of conventional energy. The main challenge in implementing these nonconventional methods is the variable and low power generated from them, which cannot be directly used to meet the normal electrical power demands where steady and high power is required. This is where power electronics comes to play. Power from say, a solar panel is conditioned to a steady and higher power AC supply using combination of different power electronic circuits such as Buck/boost converter, inverter, rectifier.
Another prominent use is in those little adapters of your laptop/tablet/mobile devices where 240V AC is converted to 5V DC to charge their batteries. Take a look around you, and you’ll find power electronic circuits in the regulator of your fan, the voltage stabilizer of your high power devices like AC, TV, refrigerators etc.. The mood lights of your bedroom are one of the simplest and latest implementations of the power control circuit.
Power electronics implementation can also be seen in your kitchen. The induction heating used to cook food on an induction stove is a classic example where the heat is controlled via a power control circuit which regulates the current which is responsible for the heating.
The uninterrupted power supply systems that continue to power up your computer during power fails, are another example of a power electronics application. The current trend of electric vehicles also uses power electronic circuits. Industries use power control circuits in traction, trolly, fork lifts etc.
The application of power electronics is overwhelming and the list is endless. All these circuits differ in the use of switches like GTO, SCR, IGBT, MOSFET, BJT, and different switching techniques that are used for different applications to suit the need.
Conclusion
Electrical energy is one of the most used forms of energy and electric power conversion and control is one of the most growing subsidiaries of electrical engineering. Power electronics is a combination of power circuits mixed with the low signal electronic circuits to meet these ever-fluctuating electric power demands. These circuits involve high power rated switches like GTO, SCR, BJT, MOSFET, etc and different passive components to get the desired output. From a simple regulator at your home to the traction circuits at various industries, you can find the application of power electronics in almost every field.
With the current trend of renewable energy garnering more attention, power electronics is undoubtedly not only the present but the future of electrical engineering across the globe.
Author: Cicy has a master's degree in electrical and electronics engineering with a specialization in Power Electronics. She is a freelance writer who writes to simplify complicated concepts in an understandable language.
