Power semiconductor devices such as SiC MOSFETs and IGBTs are widely used in a variety of applications, including commercial and military aviation, renewable energy, aerospace, automotive and transportation, test and measurement, and telecommunications. These devices play a critical role in power transfer, power conversion, and power switching and are often interchangeable, although SiC MOSFETs generally work well for lower voltages and power, while IGBTs are well adapted to higher voltages and power. Therefore, selecting the right device is critical to system safety, reliability, and efficiency. The choice of a power semiconductor device for certain applications depends on several factors, such as:
- current levels
- switching frequency
- operating temperature range
- power handling capability, and
- cost-reliability trade-offs.
In the following paragraphs, we will discuss the characteristics of SiC systems and IGBT, and evaluate the suitability of each device.
What is a silicon carbide MOSFET?
SiC (silicon carbide) systems are made, as the name says, of silicon carbide. With the introduction of silicon carbide, MOSFETs are more effective than ever before, offering unique benefits compared to traditional silicon components. It is more energy efficient, dissipates heat much better, has higher current density, operates reliably at high temperatures, and can sustain higher voltage at the same thickness compared to silicon. Therefore, silicon carbide devices have improved critical breakdown strength (10 times that of silicon), higher switching frequencies, and decreased switching losses, making them suitable for high power, high frequency applications.
In addition, silicon carbide MOSFETs require smaller peripheral components, and boast a more compact design. Silicon carbide MOSFETs are known for their reliability, lighter weight, and greater durability compared to traditional SiCMOSFETs.
SiC MOSFETs are frequently used in electrical equipment, particularly in charging batteries for electric vehicles, converting photovoltaic energy, and transforming high voltage DC to DC power. These devices are favored in renewable energy circuits because they have lower energy losses and take up less space than their silicon-based counterparts. Their compact design and improved performance make them ideal for green server power and optimizing power conversion efficiency.
What is an IGBT?
IGBTs (Insulated Gate Bipolar Transistor), on the other hand, are a type of power transistor that combines the characteristics of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) and a bipolar transistor. They can be used for both switching and amplification applications, and are commonly used in high-voltage power conversion systems. IGBTs are also capable of high-speed switching and can handle large amounts of power, making them a popular choice as switch components in inverter circuits that convert DC to AC power, enabling the operation of motors ranging from small to large. They are utilized in household appliances, such as air conditioners, refrigerators, and induction plates as well as in industrial motors and automotive main motor controllers, to enhance their efficiency. In summary, this is where you most commonly find the use of IGBTs:
- Power Inverters
- Motor Drives
- Welding Machines
- Uninterruptible Power Supplies
- Solar Power Systems
- High-Voltage DC Transmission
- Electric Vehicle Charging Stations
- High-Frequency Power Conversion
- High-Voltage Power Supplies
- Industrial Power Supplies
You can also read our article comparing IGBTs to 12-pulse rectifiers here.
In summary, as mentioned earlier, both SiC MOSFETs and IGBTs are suitable for a variety of applications. It is difficult to say which of SIC and IGBTs is more effective, as it depends on the specific application and system requirements. Factors that could influence the choice of a power semiconductor device for a particular aviation application, for example, include the voltage and current levels, switching frequency, operating temperature range, power consumption, and overall cost and reliability of the device. One thing is still certain at the time of writing: SICs are still more expensive than IGBTS and in some cases do not provide significant efficiency gains to justify the price difference.
It is important to carefully consider these and other factors when selecting power semiconductor devices, as system safety and reliability are critical in certain fields. We recommend that you consult with experts in the field or conduct testing to determine the most appropriate power semiconductor device for a particular application.
You can count on us to support you in this task.