Voltammetric characteristics of thyristor thyristor volt-ampere characteristics

It can be seen from the figure that the forward voltage is applied between the anode and the cathode of the thyristor (thyristor), and when the control electrode is not applied with voltage, the J ₁ and J ₃ junctions of the thyristor are forward biased, and the J ₂ junction is in the opposite direction. To the bias, the thyristor can only pass a small positive leakage current I _DR , the OA segment of the characteristic curve, called the forward blocking state. When the anode voltage continues to increase to the U _B0 value in the figure, the J ₂ junction is reversely broken, the anode current rises sharply, and the characteristic curve suddenly jumps from point A to point B, and the thyristor is in a conducting state.

After the thyristor is turned on, if the anode current is reduced, then I _A

When the control electrode plus current I _G

The volt-ampere characteristic when the anode voltage of the thyristor is negative is called the reverse characteristic. When the thyristor is applied with a reverse voltage, the J ₁ and J ₃ junctions are reverse biased, the J ₂ junction is forward biased, and the thyristor only flows through a small reverse leakage current. This feature is similar to the reverse characteristic of the diode, and the thyristor is in a reverse blocking state. When the reverse voltage exceeds the U _BR value in the figure, the tube is broken down, and the reverse current sharply increases, causing the thyristor to reversely conduct and become irreversible breakdown. U _BR

When the thyristor is working normally, the applied voltage must not exceed the reverse breakdown voltage, otherwise the tube will be damaged. At the same time, the applied voltage is not allowed to exceed the forward turning voltage, otherwise the control pole is added with the control current.