| 摘要 |
PURPOSE:To stably perform a constant control over the commutation marginal angle of the titled converter by a method wherein the current of said converter is lowered with the output voltage of the converter in excess of the prescribed value, and the value of commutation marginal angle command value is reduced in proportion to the decrease in current of the converter. CONSTITUTION:Before the main converter 4 attains the maximum output, a controller 18 gives a commutation marginal angle controller 15 a commutation marginal angle command value with which a marginal angle control can be obtained. Also, said controller 18 controls the firing angle of the thyristor on the main converter 4 in such a manner that the output current of the main converter 4 will have the value commanded by the operation commanding device 11. When the output voltage of the main converter 4 reaches the maximum limit of output, the output current command value of the main converter 4 is lowered by the ignition phase angle controller 18 and, at the same time, the commutation marginal angle command value, to be given to the commutation marginal angle controller 15, is also lowered. |
