APPLICATION OF POWER ELECTRONICS IN ELECTRICAL ENGINEERING

Power Electronics is nothing but a way of converting electrical energy from one form to another, the output by the conversion is a better, more efficient, error free, clean, compact,  simple and  convenient to use.

The study of power electronics and electric motor drives involves processing of electric power for a variety of uses. And provide a wide range of application within the range from a few watts to megawatts. For the example we can take various computer disk drives, drills with variable speed, lamp dimmers, electric vehicles, industrial machine tools, and electrical drives.

The area of power electronics is so vast that every day average 12 billion kilowatts per hour of power which is more than 80 % of the power generated is converted or processed or recycled by some of power electronic devices. As the power conversion efficiency is low the losses of energy during the power conversion are so high. We can understand this by a small example of estimated power consumption in a desktop sold in one year, which is equal to the 17 power plants of 500 MW. So it is very necessary to improve the efficiency of the power conversion systems.

By an estimated calculation, it has been found that with the use of efficient and economically effective power electronic technology, the world can save 35 % reduction in energy consumption.

Following are various applications with a wide power range from a few tens of watts to several hundreds of megawatts. As power semiconductor devices improve in performance, efficiency and if the cost will be reduced, more systems will undoubtedly use power electronics.

  • Residential
  • Refrigeration and freezers
  • Space heating
  • Air conditioning
  • Cooking
  • Lighting
  • Electronics (PCs, other entertainment equipment

 

  • Commercial
  • Heating, ventilating, and air conditioning
  • Central refrigeration
  • Lighting
  • Computers and office equipment
  • Uninterruptible power supplies (UPSs)
  • Elevators
  • Industrial
  • Pumps
  • Compressors
  • Blowers and fans
  • Machine tools (robots)
  • Arc furnaces and induction furnaces
  • Lighting
  • Industrial lasers
  • Induction heating
  • Welding

 

  • Transportation
  • Traction control of electric vehicles
  • Battery chargers for electric vehicles
  • Electric locomotives
  • Street cars, trolley buses
  • Subways
  • Automotive electronics, including engine controls
  • Utility systems
  • HVDC
  • SVC
  • Supplemental energy sources (wind, photo voltaic), fuel cells
  • Energy storage systems
  • Induced draft fans and boiler feedwater pumps
  • Aerospace
  • Space shuttle power supply systems
  • Satellite power systems
  • Aircraft power systems
  • Telecommunications
  • Battery chargers
  • Power supplies (DC and UPS)

It is literally impossible to list all the application of power electronics today; it has covered almost all the areas where electrical energy is being used. This has become a trend now and it is increasing, especially with the present scenario of new devices and integrated design of power semiconductor devices and controllers. The ease of manufacturing has also helped these devices to be available so now a day these devices exist in a vast range of ratings and gradually have appeared in high voltage and extra high voltage systems also. In the end it can be summaries in the words that, the day is not far when all of the electrical energy in the world will pass through power electronic systems.

 

Electric Machines & Magnetic Field

Good Morning,

As we know, today’s world is growing at very fast pace, keeping in mind of various technological innovations and the basic requirements for all such innovations brings my focus to Electrical Energy.

For all such actions available to a common man, the availability of minimum & sufficient supply of electrical energy to each is essential. So for this entire let us have a basic knowledge of Electrical Machines and the very important work done by magnetic field which made this a possibility and not a dream.

    The key point is       

“Why we use Magnetic field only as a medium of conversion in the design of electrical machines”

Take an example of Transformer –a static, non linear device used to change the voltage levels at a constant frequency. Under normal operating level voltages, electric field strength developed will be very weak. In contrary even by having very less magnitude of current, we can develop a strong magnetic field by increasing number of turns. Maximum allowed energy density for air with respect to magnetic field is more compared to electric field. In other words we can say that for a given power rating, the size of machine, volume of material requirement and the cost of machine will be less with magnetic field compared to electric field.

By the study of various experiments carried out by famous scientists like Oersted, Ampere and Faraday’s the use of magnetic field in electric machines and its behavior characteristics were made clear to us, for example by Oersted’s experiment the generation of magnetic field by passage of electric current .Next Ampere’s experiment which gave us knowledge about the direct proportionality of magnetic field or flux to the current if and only if system is linear. Finally the Faraday’s law which thoroughly explained the induction of EMF by a changing flux that brought about a revolution in the electrical engineering.

So let us face the reality , a lot has been done in the field of electrical engineering and a lot is yet to be achieved and meet the requirements .A little step by all the members of electrical fraternity and also by all those who uses it can change the present scenario of Electrical Energy generation and requirement.