1995 Volume 115 Issue 10 Pages 1284-1291
A thyristor converter is superior to GTO converter from a view point of weight and efficiency. Therefore, the thyristor converter is the best answer for AC inverter rolling stock, especially for commuter and interurban trains, in the next several years. For a thyristor converter, it is very important to prevent the commutation failure even when the catenary voltage decreases, in order to continue regenerating operation to sustain the brake torque. In a conventional system, a series resistance is inserted between the thyristor bridge and LC filter where the DC stage voltage is decreased enough to keep the regenerating power. The conventional thyristor enables regenerating braking in the whole operational region, but result in low power factor and efficiency. This paper proposes a new regenerating method to improve the power factor and efficiency, which keep regenerating power with no series resistance and higher DC stage voltage. Simulation results show the effectiveness of the method.