| 摘要 |
<p>PROBLEM TO BE SOLVED: To attain an exciting device for synchronous machine which can attain cost reduction, simple constitution, and easy maintenance. SOLUTION: This exciting device involves a thyristor bridge 3 constituted of a plurality of thyristors 3a to 3f for exciting the field winding 1a of a synchronous machine 1 connected to a system side. In stopping the synchronous machine 1, a main circuit breaker 31 is opened, the thyristors 3a to 3f of the thyristor bridge 3 are ignited simultaneously, and field energy stored in the field winding 1a is discharged through all the thyristors 3a to 3f. The resistance of a field discharge circuit at that time is almost determined by the resistance value of the field winding 1a, discharging is conducted more slowly with its discharge time constant being about 10 seconds than a conventional type whose discharge time constant is about 2 seconds, and the time of dozens of seconds, or minute unit is required for complete elimination of the field current, however, it causes no trouble in practical use.</p> |
