Development of gate-driving system of thyristor valve with multiple isolated outputs used in new-type solid-state short-circuit fault current limiter in electric power system

Abstract

The principle of new-type solid-state short-circuit fault-current limiter (FCL) is described, and its whole construction is presented accordingly. A new kind of power supply with multiple isolated outputs used for driving thyristors in FCL is developed, and a new driving-circuit topology for SCR is also presented. The chief parts of the power supply include a DC current source, a bridge-type inverter and a series of output transformers. Turns number of the primary winding of all the output transformers is one. The isolation voltage between every two outputs can be made very high if ultra-high voltage cable is adopted to make the primary winding of all the output transformers. The number and locations of outputs of the power supply can be changed very easily to meet the requirements of the thyristors in the limiter. With the increase in the voltage level and the number of power semiconductors in the electronic equipment, the proposed power supply is more advantageous. The waveform with the rise-time up to 1 /spl mu/s, which is generated by drive-circuit developed here, is able to ensure fast turn-on of SCR. In addition, the developed strong triggering pulse with time-width of 100 /spl mu/s is also able to ensure the reliability of triggering circuit.