Surge Voltage Suppression Circuit Design of On-Board SCR Controller

Abstract

SCR controller is one of the components of the SCR system, which should pass the test pulse 5b. The features and test requirements of pulse 5b are introduced. Its energy is very large, so passing the test is difficult. Two surge voltage suppression circuits are designed. The first design utilized a surge stopper-LT4356, its work process includes fault timer period, warning period and cooling period. During the cooling period, the SCR controller cannot work normally. So connecting a capacitor in parallel to the output of the surge voltage suppression circuit is used to improving its performance. The second design utilized two pieces of TVS, since the test pulse is continuous, steady state power dissipation must be considered when choose TVS. Finally, it verifies the feasibility of the two design schemes by experiments and leads to a selection criteria for them.