| 摘要 |
PURPOSE:To reduce a braking time by regeneratively braking a synchronous generator in a high speed zone, operating a changeover switch after it is lowered to the predetermined speed, and braking it with 3-phase shortcircuit circuit or resistor, thereby obtaining a large braking torque. CONSTITUTION:The rotating speed of a synchronous motor 1 is detected by a permanent magnet generator (PMG) 7, a brake controller 8 receives this detection signal and compares the detection speed with the set speed, thereby controlling the changeover switch 9. The switch 9 closed the converter, inverter 4 side in the range that the detecting speed is higher than the set speed, and accordingly the outputs of the converter and inverter 4 are regenerated to the bus line side through step-up transformer 6. When the speed is decelerated to become lower than the set speed at the detection speed, the field current is interrupted from the exciter 10, the converter and inverter 4 side of the switch 9 are opened, and the 3-phase shortcircuit side is closed, and is again excited. |
