| 摘要 |
PURPOSE:To reduce the size and the weight of an induction machine by increasing the operating frequency of a regenerative chopper higher than the frequency of a secondary chopper to suppress a current ripple merely by the leakage reactance of the machine and a transformer. CONSTITUTION:A GTO3 (secondary chopper) is turned ON, OFF to control the output current of a power reactor 2 to control the secondary current i2 of an induction motor IM1, thereby controlling a speed. A DC current is charged through a diode 4 in a capacitor 5 while the secondary chopper is OFF. A transistor 6 (regenerative chopper) is turned ON, OFF so that the voltage of the capacitor 5 becomes constant. A current flowing while the transistor 6 is ON is arrived at an inverter 8 to be regenerated to an AC power source. Here, the frequency of the secondary chopper is set to the lowest frequency limit not required for a DC reactor, and the frequency of the chopper is selected to approx. 1.5-3 times of the secondary chopper. |
