Variable frequency DC to AC converter for N:phase motor - has diode and thyristor bridges and thyristor firing capacitors and logic system

摘要

The variable frequency current convertor feeds an n phase A.C. motor from a variable D.C. supply. Between the supply source and the motor are a DC current smoothing inductance and a thyristor bridge consisting of 2 n thyristors arranged in n parallel branches with 2 thyristors in series. The mid points of each branch are connected to the n phase terminals of the machine. A switching bridge consisting of 2 n diodes arranged in n parallel branches with two diodes in series has its mid points connected to the phase terminals. The current convertor also has two capacitor firing circuits for the thyristor and a load inversion acceleration circuit and a thyristor logic control system.