Tech Insights

The Importance of Power Engineering and Power Electronics: A Brief History

May 23, 2020 by Lorenzo Mari

Power engineering and electronics, while maybe not as popular as other forms of engineering, is of great importance to the world around us and has been important for a long time.

Power electronics is an essential part of many devices and systems in one or more of their phases. Power electronics convert electrical energy of one type into another with different characteristics and is used to drive any device that requires an input of electric power other than that supplied by the primary power source.

However, that is just the technical explanation of engineering power electronics. As COVID-19 continues to spread throughout the world, we are seeing just how important engineers are and the technology they engineer can be. From power generation to transportation and communication technologies to average kitchen appliances, power electronics and the engineers behind these electronic devices are everywhere.

This short series of articles will explore the many ways power electronics permeate our daily lives — whether you are a power engineer working to develop the newest technology in the industry or anyone who benefits from modern power technologies.


Why Power Electronics? 

Power electronics is a branch of electronics that deals with the application of electronic devices and associated components to the conversion, control, and conditioning of electric power. Power electronics converters modify the primary characteristics of electrical power: the basic form AC or DC, voltage, current, frequency, and power factor.

The control of electric power allows for the regulation of nonelectrical parameters like the intensity of lighting, the speed of a motor, the rate of an electrochemical process, or the temperature of an oven.

Power electronics systems are used in a wide range of applications and have the potential to impact any area of ​​global industrial and social activity. From cellphones to pacemakers, and utilities to automobiles, power electronics, and the engineering behind those electronics are very influential in peoples’ daily lives.

The demand for electrical energy grows in direct relation to the improvement of the quality of life. In the 21st Century, the technologies associated with the manipulation and conservation of energy sources are of vital importance to ensure a comfortable standard of living. Power electronics has a crucial role in the efficient use of electrical energy and environmental control.

Power engineering reaches sectors such as residential, industrial, commercial, medical, communications, transportation, aerospace, and military.

Some of the applications of power electronics are power conditioning, electrochemical processes, temperature and lighting control, renewables power conversion, medical applications, communications, computer industry, computer networks, electric power networks, military, and transportation.



The History of Power Electronics

Power electronics emerged in the early 1900s, with the introduction of the mercury arc rectifier (Peter Cooper Hewit in 1902). Then gradually appeared the triode (Lee De Forest, 1906), the controlled grid high vacuum tube rectifier (Lee De Forest 1906), the metal tank rectifier (Errol Shand, 1925), the ignitron (Joseph Slepian,1930s). All applied to energy control until the 1950s.

In 1948 the first electronic revolution began with the invention of the silicon transistor at Bell Laboratories.

Another device that emerged was the thyristor, a name given to any semiconductor switch that bistable operation depends on p-n-p-n regenerative feedback.

The silicon controlled rectifier (SCR) is the best known of all thyristor devices and was first introduced in 1954 by Bell Laboratories. The unijunction transistor (UJT) was first introduced in 1948 but commercialized in 1952.

William Shockley, John Bardeen & Walter Brattain co-invented the transistor at Bell Laboratories. 


The second electronic revolution was in 1958 with the development of the commercial thyristor by General Electric Company. This ushered in a new era of power electronics.

Power semiconductor devices introduced to date are the bipolar junction transistor (BJT), metal-oxide-field effect transistor (MOSFET), gate turn-off switch (GTO), MOS Controlled Thyristor (MCT), and hybrid devices such as insulated-gate bipolar junction transistor (IGBT).


Semiconductor Applications

A semiconductor is often the most important aspect of any piece of technology — an essential component of any electronic device. 

Some general applications of the semiconductors used today in the power electronics industry are:

  • Triacs: phase control is an initial application, also, as a static switch.
  • Silicon controlled rectifier (SCR): relay controls, time delay circuits, regulated power supplies, static switches, motor controls, choppers, inverters, cyclo converters, regulators for battery charger, protection circuits, lighting control, heater controls, and phase controls.
  • Bipolar junction transistors (BJTs): amplifiers, oscillators, multivibrators, timers and delay time circuits, and switching devices.
  • Unijunction transistor (UJT): oscillators, trip circuits, sawtooth generators, phase controls, timing circuits, bistable networks, and regulated voltage or current sources.
  • Metal-oxide-semiconductor field-effect transistor (MOSFET): radio frequency power amplifiers, switching power supplies, power converters, lighting control, motor control, choppers, and voltage regulators.
  • Gate turn-OFF switch (GTO): counters, pulse generators, multivibrators, and voltage regulators.
  • MOS Controlled Thyristor (MCT): high power, soft switching converters, smart weapons, circuit breakers, and electric vehicles.
  • Insulated-gate bipolar junction transistor (IGBT): motor drives, UPS, switched power supplies, traction motor control, induction heating, and inverters

Power electronics give us the ability to shape and control large amounts of energy with increasing efficiency.


Read more from this series of articles on the importance of power electronics engineering: 

Power Meets Medicine 

Power Electronics in ICT Systems

Power Electronics and Power Systems


About the author

Lorenzo Mari has been a university professor since 1982, teaching topics as electric circuit analysis, electric machinery, power system analysis, and power system grounding. As such, he has written many articles to be used by students as learning tools. He also created five courses to be taught to electrical engineers in career development programs, i.e., Electrical Installations in Hazardous Locations, National Electrical Code, Electric Machinery, Power and Electronic Grounding Systems and Electric Power Substations Design. As a professional engineer, Mari has written dozens of technical specifications and other documents regarding electrical equipment and installations for major oil, gas and petrochemical capital projects. He has been EPCC Project Manager for some large oil, gas & petrochemical capital projects where he wrote many managerial documents commonly used in this kind of works.