| 摘要 |
PROBLEM TO BE SOLVED: To control first and second chopper means smoothly by controlling the first chopper such that a first DC voltage is applied to a capacitor and controlling the second chopper such that a second DC voltage higher than the first DC voltage is applied to a capacitor. SOLUTION: A booster chopper 8 comprises a reactor 81, a control element 82 and a diode 83 and controls the power supply current sinusoidally under powering. A step-down chopper 9 comprises a resistor 91 and a control element 92 and controls operation for recovering power from a motor 5. During powering period, operation is controlled to sustain the DC voltage Ed of a capacitor 3 at a voltage command Ed1* while supplying a sine wave input current is from an AC power supply 1 with such a magnitude as corresponding to the power being supplied to the motor 5 from a first chopper, i.e., the booster chopper 8. During powering period, the input current is controlled substantially sinusoidally and power recovery is processed in the apparatus during recovery period. |
