What are IGBTIGCT and IEGT? What is the culprit of IGBT failure?
What are IGBT, IGCT and IEGT respectively, and what are the differences and commonalities? Comparison of GBT and integrated gate commutated thyristor IGCT
Limited by the current technical level, the working current of IGBT is relatively small, and the more commonly used medium and high voltage and high power IGBT has several specifications such as 1700V/2400A, 3300V/1200A, 4500V/ 900A, 6 500V/ 600 A, etc. The output capacity of the converter using the unit is generally not more than 1.6MVA, if you want to further increase the output capacity, you can only use the parallel connection of the components or the converter. Whether the components are connected in series or parallel or the converter is connected in parallel, the complexity of the system will be increased and the efficiency and reliability will be reduced.
Compared with GTO, GCT has more obvious advantages: (1) there is no need to turn off the absorption circuit, which can reduce the volume and weight of the converter, improve the efficiency and reliability of the converter, and reduce the cost. Although the absorption circuit needs to be turned off when used in series, the volume is much smaller than that of GTO: (2) The gate drive circuit is integrated in the IGCT, and only the gate drive power supply interface and the optical fiber for transmitting the trigger signal and feedback state can improve the anti-electromagnetic interference capability of the converter; (3) Small on-state and off loss. The following figure shows the comparison of IGBT, GTO and IGCT at 3.3kV
Figure 1: Comparison of IGBT with IGCT and GTO
As can be seen from the comparison of the above figure :IGCT loss is less. The switching loss of the three devices is not much different, and the switching loss of IGCT and GBT is twice different, but the driving power of IGCT is much larger than that of IGBT. In short, IGBT in lower voltage applications, IGBT conduction loss is low, so cost-effective. IGCT is cost-effective at higher voltages. There is overlap between 1800V and 3300V according to the use occasion and design standard.
Comparison of IGBT and electron injection enhanced gate transistor IEGT
IGBT is a MOS gate device, its gate is driven by voltage, high switching speed, so it has been widely used in the field of high frequency, but it also has some problems, such as low operating voltage, small capacity, high on-voltage drop and loss, which also limits its application. IEGT is a new device that has its advantages and overcomes its disadvantages. Commercial products have been developed in recent years. Compared with traditional devices, it has the advantages of low on-state voltage, small gate drive current, large power density, small switching loss and fast speed. FIG. 2 shows the comparison of IEGT and GTO gate parameters, and FIG. 3 shows the comparison of 4.5KV/3KAJEGT, GTO and IGCT performance for typical specifications.