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At a Glance of solid-state Power electronics

In our today’s blog, we will discuss What is Power electronics?, Power semiconductor devices and their classification into different types such as Thyristors and Gate/ Base commutated devices

Introduction to Power electronics

Before starting with power electronics, we need to understand its importance. Why it is essential to learn and where we can use the power electronics.

Electrical engineering is the field of engineering that contains three specialization topics.

Electronics
Control
power

Electronics: The electronics area includes the study of semiconductor devices and circuits for processing information at low levels.

Control: The control area includes stability and response characteristics of a close loop system using a feedback system.

Power: The power area includes rotating and static equipment for the generation, transmission, distribution, and utilization.

What is Power electronics?

Power electronics is the use of electronics to control and convert a large amount of electrical power.

In addition to this, power electronics is the link between the electrical high power system and the automation system.

In the 21^st century, we need electrical energy generation and global industrial atomization.

Therefore, in this process, power electronics convert this high power energy into low signal levels. The automation system and some other electronic devices can also handle it.

Power electronics has extensive applications however some typical applications which are equally important are

Industrial automation
Energy system
Energy generation and conversion
Switch-mode power supply (SMPS)
Uninterrupted power supply (UPS)
Heating and lighting
Electrochemical active filtering
Photovoltaic system
Robotics

The modern area of solid-state power electronics

The modern area of solid-state power electronics began with the advent of thyristors (Silicon controlled rectifiers) in the late 1950^s and other devices such as Triac (1958), Gate turn off thyristor (GTO-1958), Bipolar junction transistor (BJT) ( 1975), Insulation gate bipolar junction transistor (IGBT) (1985), Static induction transistor (SIT-1975), Integrated gate commutated thyristors (IGCT – 1987) were invented in the last decades of 29^th century, therefore, it has been called the “decade of power electronics.”

Thyristor: Thyristors, mostly known as SCR, was the first power device to get invented, primarily used for high-frequency applications. However, it can also be used in HVDC (high voltage direct current), static phase control type static VAR compensator, cycloconverter (used for AC to AC conversion), Load commutated inverter (LCI), synchronous machine drives, etc. consequently the highest-rated thyristors of rating 8KV and 4KA are also available nowadays.

ABB Company introduced the new monolithic thyristor AC switches of voltage rating 2.8 KV- 6.5 KV and current rating of 3KA – 6KA.

GTO: Gate turn off thyristor (GTO) replaced the thyristor fed inverter due to its efficient working.

In 1988 Infineon Technology, Germany included a cool MOS of 600v with 20% conduction loss and switching losses.

BJT appeared and fell into obsolesce due to IGBT (used at the higher end) and MOSFET (used at the lower end).

A thyristor to the highest voltage IC and power MOSFET the solid-state power electronics is increasing day by day. A device of VLSI complexity contains up to 150000 separate transistors.

Power semiconductor devices

The power semiconductor devices can be classified into two categories

According to the degree of controllability.
According to the nature of their controllability.

What is Power electronics?, Power semiconductor devices, and their classification into different types such as Thyristors and Gate/ Base commutated devices

1. According to the degree of controllability

Uncontrolled turn on and off: the devices we cannot control on either turn on or turn off are the uncontrolled turn on and off devices.

The device that comes under this category is a diode; however, the turn on and off state of these devices is controlled by a power circuit.

Controlled turn on an uncontrolled turn off: For the devices that come under this category, we can control the turn-on state, but we cannot control the turn of state of the device.

The device that comes under this category is SCR. moreover, The turn-on of this device is done by using a control signal, and the turn-off state is controlled by a power circuit.

Controlled turn on and off: both the on-state and off-state of the devices that come under this category can be controlled.

The device comes under this category are BJT, MOSFET, IGBT. besides turn on and off state of these devices can be controlled by using a control signal. consequently, the MOSFET is a low power device and the IGBT is a high power device.