| 摘要 |
PURPOSE:To reduce the size of an AC elevator by consuming a regenerative power in a motor in a range that a motor heat is allowable, and consuming the power through a regenerative resistor over the range. CONSTITUTION:A compensator 16 generates a power drive torque command when an elevator starts. When the elevator enters a decelerating step, the compensator 16 generates a brake torque command, a current value instructing circuit 32 outputs an absolute value of a current in response to the torque command, and a frequency instructing circuit 31 outputs a frequency command necessary for a motor speed. A current command composite circuit 38 combines them, outputs a command value of the output current of an inverter 7, and a PWM unit 36 controls the transistor of the inverter 7. When the regenerative power is returned and a DC side voltage becomes higher than a DC current command value 37, a transistor base drive circuit 39 conducts a transistor 6 to consume the regenerative power by a resistor 5. |
