1.1 Introduction
Power Electronics deals with the applications of solid state electronic devices in the control and conversion of electric power. Power Electronics has seen a tremendous growth in recent times and almost all the applications today use power electronic devices in some or the other form. Hence it becomes essential to study the advantages of these devices, which made it so popular. The first Power Electronic Device invented was the Mercury Arc Rectifier during the year 1900. Then the other Power devices like metal tank rectifier, grid controlled vacuum tube rectifier, ignitron, phanotron, thyratron and magnetic amplifier, were invented & used gradually for power control applications until 1950. The first SCR (silicon controlled rectifier) or Thyristor was found and developed by Bell Lab's in 1956 which was the first PNPN transistor. The second electronic revolution began in the year 1958 with the development of the commercial grade Thyristor by the General Electric Company (GE). Thus the new area of power electronics was born. After that many different types of power semiconductor devices & power conversion methods have been introduced. The power electronics innovation is giving us the ability to convert shapes and control large amounts of power.
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Limitations of the Study and Definition of technical terms.
1.2 Background of Study
The history of power electronics goes back more than 100 years. It began at the dawn of the 20th century with the invention of the mercury-arc rectifier by the American inventor Peter Cooper Hewitt, beginning what is called the “classical era” of power electronics. However, even before the classical era started, many power conversion and control functions were possible using rotating electrical machines, which have a longer history. Power electronics is a technology that deals with the conversion and control of electrical power with high-efficiency switching mode electronic devices for a wide range of applications. These include as dc and ac power supplies, electrochemical processes, heating and lighting control, electronic welding, power line volt–ampere reactive (VAR) and harmonic compensators, high-voltage dc (HVdc) systems, flexible ac transmission systems, photovoltaic and fuel cell power conversion, high-frequency (HF) heating, and motor drives. We can define the 21st century as the golden age of power electronics applications after the technology evolution stabilized in the latter part of the past century with major innovations.
The systems and machines of our world depend on power electronics for the ability to run efficiently and sustainably. Power electronics is the application of solid-state electronics for the control and conversion of electric power. It applies to both the systems and products involved in converting and controlling the flow of electrical energy, allowing the electricity needed for everyday products to be delivered with maximumm efficiency in the smallest and lightest package.
The evolution of power electronics is over the past 100-plus years. It includes electrical machines, mercury-arc rectifiers, gas tube electronics, Mas, power semiconductor devices, converter circuits, and motor drives. Wherever possible it gives the name of the inventor and the year of invention for important technologies. It is important to note, however, that inventions are generally developed by a number of contributors working over a period of time. The history of power electronics is so vast that it is impossible to review it within a few pages. More information is available in the references.
Power electronics is ushering in a new kind of industrial revolution because of its important role in energy conservation, renewable energy systems, bulk utility energy storage, and electric and hybrid vehicles, in addition to its traditional roles in industrial automation and high-efficiency energy systems. It has emerged as the high-tech frontier in power engineering. From current trends, it is evident that power electronics will play a significant role in solving our climate change (or global warming) problems, which are so important.
Power electronics has recently emerged as a complex and multidisciplinary technology after the last several decades of technology evolution made possible by the relentless efforts of so many university scientists and engineers in the industry. The technology embraces the areas of power semiconductor devices, converter circuits, electrical machines, drives, advanced control techniques, computer-aided design and simulation, digital signal processors (DSPs), and field-programmable gate arrays (FPGAs), as well as artificial intelligence (AI) techniques.
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to know the Power Electronics Devices with Its Application.
1.3 Statement of Problem
Investigation reveals the challenges of the Power Electronics Devices which entails that, the regeneration of power is difficult in power electronic systems, AC to DC and AC converter operate at a low input power factor under certain operating conditions and power electronic controllers have low overload capacity.
1.4 Aim and Objectives of Study
The aim of the study is to scrutinize the Power Electronics Devices with Its Application. In achieving this aim, the following specific objectives were laid out as follows:
- To deal with the study of the part of engineering that deals with the application of power semiconductor devices for the control and conversion of electric power.
- To find out the application areas of power electronics devices
1.5 Significance of Study
Apart from power generation, power electronics devices processing plays a key role in efficient utilization of the available power. It is important that the raw power is converted to a form that is usable in different applications. Power electronics plays a pivotal role in providing power based on the desired specifications. The basic application which shows the significance of power electronics in our day-to-day life is the fan regulator. Before the advent of solid-state fan regulators, bulky and lossy resistive fan regulators were used. To control the fan speed, the AC mains voltage is passed through a resistor that is connected in series with the fan. This study will be of immense benefit to researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.
1.6 Scope of Study
The capabilities and economy of power electronics system are determined by the active devices that are available. Their characteristics and limitations are a key element in the design of power electronics systems. Formerly, the mercury arc valve, the high-vacuum and gas-filled diode thermionic rectifiers, and triggered devices such as the thyratron and ignitron were widely used in power electronics. As the ratings of solid-state devices improved in both voltage and current-handling capacity, vacuum devices have been nearly entirely replaced by solid-state devices.
1.7 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet).
1.8 Definition of Terms
Power Electronics: A field of electrical engineering that deals with the application of power semiconductor devices for the control and conversion of electric power.
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