Thyristors anode current

Figure 3.21 Thyristor anode current (/ versus anode-to-cathode voltage (V ) characteristic.

In pulse-power applications, the thyristor is required to supply energy to the load in a very short period of time, which requires that it provide extremely high-current slew rates. During turn-on, excess carrier density increases near the gate area and then spreads throughout the device. As the excess carriers spread, the anode-to-... 

When choosing rectifiers it is necessary to take into account the type of anodic material, which could be prone to corrosion attack caused by dc current ripples. The effect of dc ripples from cathodic protection rectifiers is relatively less known by installation users. At high thyristor ignition angles, when the current waveform is in the form of pins, corrosion of Ti/Pt anodes occurs. Efird (1982) has shown a disadvantageous effect of the shape of the current waveform on the premature failure of Nb/Pt anodes in a CP system of two North Sea offshore oil production platforms. Juchniewiczetal. (1981) have shown that the current waveform from a thyristor power source causes accelerated corrosion of platinum and platinized titanium anodes exposed in 0.1 M NaCl solution (see Fig. 8-15). 

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