| 摘要 |
PURPOSE:To prevent a field loss due to the control delay of an automatic power-factor regulator by increasing a field current forcibly according to a rising speed of a load. CONSTITUTION:When a load rise signal is given in APFR-controlled no-load running of a brushless synchronous motor SM, the control of a thyristor rectifier THY is switched over to a constant excitation controller CEC. The normally closed contact X0b2 of a relay is opened, the normally opened contact X1a thereof is closed, and a field voltage setter is switched from 70R to 70R1. After that, a field voltage regulator is switched from 70R2 to 70R3 according to a time interval. At that time, field voltage regulators 70R1, 70R2, 70R3 are respectively regulated to the light, middle and heavy loads of field voltage to increase a field current forcibly. |
