| 摘要 |
PURPOSE:To contrive the prevention of starting failure by a variation in load condition by a method wherein an optimum starting pattern generating device is provided and the commutation timing of a power inverter is controlled together with a power rectifier and a starting thyristor. CONSTITUTION:When a starting thyristor 12 is fired by charging a starting capacitor 11, an oscillating voltage is generated at LC resonance circuits 4, 5 through a matching transformer 2 and the oscillating voltage is fed back to a control circuit 14 for monitoring starting condition through a detector 3. An oscillation frequency is detected by the circuit 14 to transmit the oscillation frequency to an optimum starting pattern generating device 15 and starting characteristics are analysed by an oscillation frequency signal in the device 15. And a starting pattern previously programmed is selected and the starting pattern is also corrected by the other starting condition element to transmit an optimum starting pattern signal to the circuit 14. In this way, the commutation timing of a power inverter 7 is controlled through a firing control circuit 8 and the voltage control of a power rectifier 6 at the time of starting and the stop timing control of a starting thyristor are also performed. |
