| 摘要 |
PURPOSE:To prevent the damage of a collector ring and the abnormal wear of a brush by altering the current density of the brush in response to the temperature of the brush, thereby maintaining the temperature of the brush in an adequate range. CONSTITUTION:When a rotary electric machine is operated with a rated load, a thyristor 17a of a switching unit 17 for coupling a brush 9a and a brush 9b is conducted to energize the brushes 9a, 9b. The temperature of the brush 9a is detected by a temperature sensor 15, and compared with the set value in a temperature detector 16. When the temperature of the brush 9a is, for example, lower than the set value, the thyristor 17a is controlled to be deenergized by a phase controller 19 to increase the current of the brush 9a, thereby rising the temperature of the brush 9a. |
