Understanding Insulated-Gate Bipolar Transistors (IGBTs) in Power Electronics

Introduction

Insulated-gate bipolar transistors (IGBTs) are semiconductor devices that combine the high input impedance of a metal-oxide-semiconductor (MOS) device with the high current-handling capability of a bipolar junction transistor (BJT). This combination makes IGBTs ideal for use in power electronics applications, such as motor drives, power supplies, and voltage regulators.

Structure and Operation of IGBTs

An IGBT consists of a p-type substrate with an n-type emitter and a p-type base. A thin oxide layer is formed between the base and the emitter, which acts as an insulating layer. A gate electrode is placed on top of the oxide layer, which controls the flow of current between the emitter and the collector.

When the gate voltage is applied, the oxide layer becomes conductive, allowing electrons to flow from the emitter to the collector. The amount of current that flows is proportional to the gate voltage. When the gate voltage is removed, the oxide layer becomes non-conductive, preventing current from flowing between the emitter and the collector.

Advantages of IGBTs

IGBTs offer several advantages over other power devices, including:

• High input impedance: The gate of an IGBT is insulated from the rest of the device, resulting in a very high input impedance. This makes IGBTs easy to drive with low-power control circuits.
• High current-handling capability: IGBTs can handle high currents without overheating. This makes them ideal for use in applications where large amounts of power are being switched.
• Fast switching: IGBTs can switch on and off very quickly, making them suitable for use in applications where high-speed switching is required.
• Low on-state resistance: The on-state resistance of an IGBT is very low, which results in low power losses. This makes IGBTs very efficient in power conversion applications.

Applications of IGBTs

IGBTs are used in a wide range of power electronics applications, including:

• Motor drives: IGBTs are used to control the speed and torque of electric motors.
• Power supplies: IGBTs are used to convert AC power to DC power.
• Voltage regulators: IGBTs are used to regulate the voltage of power supplies.
• Inverters: IGBTs are used to convert DC power to AC power.
• Uninterruptible power supplies (UPS): IGBTs are used to provide backup power in the event of a power outage.

IGBT Market

The global IGBT market is expected to reach $15.2 billion by 2028, up from $6.9 billion in 2021. This growth is being driven by the increasing demand for IGBTs in renewable energy applications, such as solar and wind power.

Market Shares of Leading IGBT Manufacturers

The leading manufacturers of IGBTs include:

• Infineon: 34%
• Mitsubishi Electric: 22%
• ABB: 18%
• Toshiba: 12%
• STMicroelectronics: 10%

IGBT Trends

Some of the key trends in the IGBT market include:

• Increasing demand for IGBTs in renewable energy applications: The growing adoption of solar and wind power is driving the demand for IGBTs used in power electronics systems.
• Development of new IGBT technologies: Manufacturers are developing new IGBT technologies with higher efficiency, lower switching losses, and smaller footprints.
• Increasing use of IGBTs in automotive applications: IGBTs are being used in a variety of automotive applications, such as electric vehicles, hybrid vehicles, and power steering systems.

Conclusion

IGBTs are essential components in power electronics applications. They offer a unique combination of high input impedance, high current-handling capability, fast switching, and low on-state resistance. As a result, IGBTs are used in a wide range of applications, from motor drives to power supplies to voltage regulators.