5SHY4045L0001可控硅IGCT板卡5SHX2645L0002当IGCT工作在导通状态时，是一个像晶闸管一样的正反馈开关，其特点是携带电流能力强和通态压降低。在关断状态下，IGCT门–阴极间的pn结提前进入反向偏置，并有效地退出工作，整个器件呈晶体管方式工作，该器件在这两种状态下的等效电路图，所示 IGCT关断时，通过打开一个与阴极串联的开关(通常是MOSFET)，使P基极n发射极反偏，从而迅速阻止阴极注入，将整体的阳极电流强制转化成门极电流(通常在lµs内)，这样便把GTO转化成为一个无接触基区的PNP晶体管，消除了阴极发射极子收缩效应。这样，它的最大关断电流比传统GTO的额定电流高出许多。5SHY4045L0001可控硅IGCT板卡5SHX2645L0002由于IGCT在增益接近1时关断，因此，保护性的吸收电路可以省去。
5SHY4045L0001
由于IGCT内部是在基极开路的状态下以晶体管模式对阳极电流进行关断，可以避免出现所谓的“GTO”状态，关断过程中允许更高的阳极电压上升率，而且关断动作非常可靠因此IGCT兼有晶闸管的低通态压降和高阻断电压，以及晶体管稳定的关断特性，是一种比较理想的大功率半导体开关器件。由于门极驱动电路必须在关断过程中迅速转移所有的阳电流。因此，IGCT设计必须采用电感相当低的门极驱动电路。实际中可根据器件要求采用多层布线印刷线路板。
5SHY4045L0001
IGCT与GTO相似，也是四层三端器件，GCT内部由成千个GCT组成，阳极和门极共用，而阴极并联在一起。与GTO有重要差别的是IGCT阳极内侧多了缓冲层，以透明阳极代替GTO的短路阳极。导通机理与GTO完全一样，但关断机理与GTO完全不同，在IGCT的关断过程中，GCT能瞬间从导通转到阻断状态，变成一个pnp晶体管以后再关断，ABB 5SHY4045L0001所以无外加du/dt限制;而GTO经过一个既非导通又非关断的中间不稳定状态进行转换(即’GTO区’)，所以GTO需要很大的吸收电路来抑制重加电压的变化率du/dt。阻断状态下IGCT的等效电路可认为是一个基极开路、低增益pnp晶体管与栅极电源的串联。
5SHY4045L0001
The 5SHY4045L0001 thyristor IGCT board 5SHX2645L0002 is a positive feedback switch similar to a thyristor when the IGCT is in a conduction state, characterized by strong current carrying capacity and reduced on state voltage. In the off state, the pn junction between the IGCT gate and cathode enters reverse bias in advance and effectively exits operation. The entire device operates in a transistor mode. The equivalent circuit diagram of the device in these two states shows that when the IGCT is turned off, by opening a switch (usually MOSFET) in series with the cathode, the P base n emitter is reversed, thereby quickly preventing cathode injection, Forcing the overall anode current into gate current (usually within l µ s) converts GTO into a contactless base PNP transistor, eliminating the cathode emitter contraction effect. In this way, its maximum breaking current is much higher than the rated current of traditional GTO. The 5SHY4045L0001 thyristor IGCT board 5SHX2645L0002 eliminates the protective absorption circuit due to the IGCT turning off when the gain is close to 1.
5SHY4045L0001
Due to the fact that the IGCT internally switches off the anode current in a transistor mode in a base open circuit state, the so-called “GTO” state can be avoided. During the shutdown process, a higher rate of anode voltage rise is allowed, and the shutdown action is very reliable. Therefore, IGCT combines the low on state voltage drop and high blocking voltage of thyristors, as well as the stable shutdown characteristics of transistors, making it an ideal high-power semiconductor switching device. Due to the fact that the gate drive circuit must quickly transfer all positive current during the shutdown process. Therefore, IGCT design must use gate drive circuits with relatively low inductance. In practice, multi-layer wiring printed circuit boards can be used according to device requirements.
5SHY4045L0001
IGCT, similar to GTO, is also a four layer three terminal device. The GCT is composed of thousands of GCTs internally, with the anode and gate shared, and the cathode connected in parallel. An important difference from GTO is the addition of a buffer layer on the inner side of the IGCT anode, replacing the short-circuit anode of GTO with a transparent anode. The conduction mechanism is completely the same as GTO, but the turning off mechanism is completely different from GTO. During the turning off process of IGCT, GCT can instantly transition from conduction to blocking state, become a pnp transistor, and then turn off again. Therefore, ABB 5SHY4045L0001 has no external du/dt limit; And GTO undergoes a transition through an intermediate unstable state that is neither on nor off (i.e. the ‘GTO region’), so GTO requires a large absorption circuit to suppress the rate of change of the re applied voltage du/dt. The equivalent circuit of IGCT in the blocking state can be considered as a series connection of a base open circuit, low gain pnp transistor, and gate power supply.
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