IGCT在整流环节中与SCR一脉相承，SCR是Silicon Controlled Rectifier的缩写，是可控硅整流器的简称。可控硅有单向、双向、可关断和光控几种类型。它具有体积小、重量轻、效率高、寿命长、控制方便等优点，被广泛用于可控整流、调压、逆变以及无触点开关等各种自动控制和大功率的电能转换的场合单向可控硅是一种可控整流电子元件，能在外部控制信号作用下由关断变为导通，但一旦导通，外部信号就无法使其关断，只能靠去除负载或降低其两端电压使其关断。单向可控硅是由三个PN结PNPN组成的四层三端半导体器件，与具有一个PN结的二极管相比，单向可控硅正向导通受控制极电流控制;与具有两个PN结的三极管相比，差别在于可控硅对控制极电流没有放大作用。双向可控硅具有两个方向轮流导通、关断的特性。双向可控硅实质上是两个反并联的单向可控硅，是由NPNPN五层半导体形成四个PN结构成、有三个电极的半导体器件。

IGCT is in line with SCR in the rectification process, which stands for Silicon Controlled Rectifier. There are several types of thyristors, including unidirectional, bidirectional, switchable, and optoelectronic. It has the advantages of small size, light weight, high efficiency, long service life, and convenient control. It is widely used in various automatic control and high-power power conversion scenarios such as controllable rectification, voltage regulation, inverter, and contactless switch. Unidirectional thyristor is a controllable rectification electronic component that can turn off to on under the action of external control signals. However, once it is turned on, the external signal cannot turn it off, and it can only be turned off by removing the load or reducing the voltage at both ends. Unidirectional thyristor is a four layer, three terminal semiconductor device composed of three PN junctions. Compared with diodes with one PN junction, the forward conduction of unidirectional thyristor is controlled by the control pole current; Compared with a transistor with two PN junctions, the difference is that the thyristor has no amplification effect on the control electrode current. Bidirectional thyristor has the characteristic of alternating conduction and turn off in two directions. Bidirectional thyristors are essentially two anti parallel unidirectional thyristors, which are semiconductor devices formed by NPNPN five layer semiconductors with four PN structures and three electrodes.