Device for driving elevator at service interruption
First Claim
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1. A device for driving an elevator at the time of a service interruption comprising:
- an induction motor for driving an elevator,a converter for converting the AC voltage supplied by a commercial power source into a DC voltage,a capacitor for smoothing the DC voltage obtained by said converter,a DC voltage detector for detecting the DC voltage across said capacitor,a regular inverter for converting the DC voltage smoothed by said capacitor into an AC voltage to drive and control said induction motor,a control circuit for generating an AC voltage command value and outputting it to said regular inverter,a battery for supplying power to said regular inverter when the commercial power source is interrupted, anda DC voltage suppression means for controlling the DC voltage command value generated by said control circuit by controlling the DC voltage across said capacitor detected by said DC voltage detector so that the DC voltage across said capacitor does not exceed a set value when the commercial power source is interrupted.
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Abstract
The device for driving an elevator at the time of a service interruption according to the present invention has a circuit for varying d-axis magnetic flux command to prevent regeneative power that can damage the elements in an inverter from being generated at the time of an interruption eliminating the need for a regenerative power consumption circuit.
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Citations
8 Claims
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1. A device for driving an elevator at the time of a service interruption comprising:
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an induction motor for driving an elevator, a converter for converting the AC voltage supplied by a commercial power source into a DC voltage, a capacitor for smoothing the DC voltage obtained by said converter, a DC voltage detector for detecting the DC voltage across said capacitor, a regular inverter for converting the DC voltage smoothed by said capacitor into an AC voltage to drive and control said induction motor, a control circuit for generating an AC voltage command value and outputting it to said regular inverter, a battery for supplying power to said regular inverter when the commercial power source is interrupted, and a DC voltage suppression means for controlling the DC voltage command value generated by said control circuit by controlling the DC voltage across said capacitor detected by said DC voltage detector so that the DC voltage across said capacitor does not exceed a set value when the commercial power source is interrupted. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A device for driving an elevator at the time of a service interruption comprising:
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an induction motor for driving an elevator; a converter for converting the AC voltage supplied by a commercial power source into a DC voltage; a capacitor for smoothing the DC voltage obtained by said converter; a DC voltage detector for detecting the DC voltage across said capacitor; a first inverter for converting the DC voltage smoothed by said capacitor into an AC voltage to drive and control said induction motor; a control circuit for generating an AC voltage command value and outputting the AC voltage command value to said regular inverter; a battery for supplying power to said regular inverter; first and second switches connected between said battery and said regular inverter, said first and second switches being closed when the commercial power source is interrupted; a voltage command generating circuit for generating a DC voltage command; a first subtractor connected to said voltage command generating circuit and to said DC voltage detector for generating a difference signal representative of the difference between the DC voltage command and the DC voltage across said capacitor; a DC voltage controller for generating a d-axis magnetic flux correction value according to the difference signal generated by said first subtractor; a switch which interconnects said DC voltage controller with said control circuit and which is closed when the commerical power source is interrupted.
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Specification