Emergency operation processes in the thyristor rectifier of an alernating current electric locomotive

Abstract

In an electric locomotive, the failure of any element or unit of the control system does not have to cause damage to power circuits or emergency operation. A control strategy for a four-zone ac–dc power converter with a discharge diode branch, which is connected in parallel to the rectified current circuit, is proposed. Such control improves the switching conditions of thyristors and allows reduction in the switching time and a decrease in the equivalent inductive reactance of the ac circuit; in addition, it provides reservation due to simultaneous switching of paralleled thyristor branches and skipping of control pulses in any control zone.