Overview of Power Electronics Technology

Overview of Power Electronics Technology

Electronic technology includes two major branches: information electronic technology and power electronic technology. Generally speaking, analog electronic technology and digital electronic technology belong to information electronic technology. The so-called power electronic technology is the electronic technology applied in the power field, that is, the technology that uses power electronic devices (such as thyristors, GTO, IGBT, etc.) to transform and control electrical energy. The “electric” power transformed by power electronics technology can be as large as hundreds of megawatts or even gigawatts, or as small as several watts or even less than 1W. Different from information electronic technology, which focuses on information processing, power electronic technology is mainly used for power conversion. Generally, there are two types of power used: AC and DC. In actual use, power conversion is often required. Power conversion can generally be divided into four categories, namely, AC to DC (rectification), DC to AC (inverter), DC to DC (chopping), and AC to AC (AC power control). The technology for performing the above-mentioned power conversion is called variable current technology. The manufacturing technology of power electronic devices is the foundation of power electronic technology, and its theoretical foundation is semiconductor physics. And the current conversion technology is a technology that uses power electronic devices to form a power conversion circuit and control it. It is the core of power electronic technology, and its theoretical basis is circuit theory.

The term Power Electronics emerged in the 1960s. “Power electronics” and “power electronics technology” are not very different in content, but are called from two different perspectives, academic and engineering technology. In 1974, W. Newell of the United States used the inverted triangle of Figure 1 to describe power electronics. He believed that power electronics was formed by the intersection of three disciplines: power, electronics, and control theory. This view has been generally accepted all over the world.

Overview of Power Electronics Technology
Figure 1 – An inverted triangle describing power electronics

The relationship between power electronics technology and electronics is obvious. Electronics can be divided into two parts: electronic devices and electronic circuits, which correspond to power electronic devices and power electronic circuits respectively. From the point of view of the manufacturing technology of electronic and power electronic devices, the two have the same root, and the analysis methods of the two circuits are also the same, but the purpose of the two applications is different. The former is used for power conversion and the latter is used for information processing.

Power electronics technology is widely used in electrical engineering, which is the main relationship between power electronics and electric power. Electricity is the science of electrical engineering or electrical engineering. Various power electronic devices are widely used in power systems and electrical engineering such as high-voltage direct current transmission and high-performance AC and DC power supplies. Therefore, power electronic technology is classified as electrical engineering. Power electronics technology is the most active branch of the electrical engineering discipline. The continuous advancement of power electronics technology has greatly promoted the modernization of electrical engineering.

Control theory is widely used in power electronic technology to optimize and improve the performance of power electronic devices and systems, which can meet people’s various needs. Power electronics technology can be regarded as the technology of weak current controlling strong current, and it is the interface between weak current and strong current. The control theory is a powerful link to realize this interface. In addition, control theory and automation technology are inseparable, and power electronic devices are the basic devices and important supports of automation technology.

In China, power electronics and power transmission are a secondary discipline of electrical engineering. Figure 2 describes the electrical engineering with two triangles. The big triangle describes the relationship between the first-level discipline of electrical engineering and other disciplines, and the small triangle describes the relationship between the second-level disciplines in the first-level discipline of electrical engineering.

Overview of Power Electronics Technology
Figure 2 – Double triangle description of electrical engineering

Some people predict that power electronics technology and motion control, together with computer technology, will become the two pillars of future science and technology. The role of the computer is usually compared to the human brain. Then, power electronics technology can be compared to human digestive system and circulatory system. Power electronics technology, together with motion control, is equivalent to human muscles and limbs, enabling people to exercise and engage in labor. Power electronics technology is an electric energy conversion technology, a technology that turns “crude electricity” into “fine electricity”. Energy is an eternal topic in human society, and electricity is the highest quality energy source. Therefore, as a brand-new technology, power electronics technology will continue to develop at a rapid pace in the 21st century.