Apparatus for controlling an elevator
First Claim
1. In an elevator controlling apparatus in which an alternating current supplied from a power source is converted into a direct current by a converter, and said direct current is further converted into a variable-voltage and variable-frequency alternating current for controlling a hoist motor,the improvement comprising:
- regenerated power detecting means for producing a first signal when said hoist motor is regenerating electric power;
resistor means, connected to the direct current side of the converter, for consuming the regenerated power in response to said first signal;
consumed power detecting means, coupled to said resistor means, for detecting the amount of the regenerated power being consumed by said resistor means and for producing a second signal when said amount is in excess of a predetermined value; and
regenerative inverter means, actuated in response to said second signal, for returning the excess regenerated power to said power source.
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Accused Products
Abstract
An elevator control system connected to a source of three-phase alternating current which is rectified by a converter to direct current which is converted to a variable-voltage variable-frequency A.C. voltage which, in turn, drives the elevator hoist motor. A resistor and a switch are connected across the D.C. terminals of the converter. When the motor is operating in the regenerative mode, the switch is closed to permit the regenerated circuit to flow through the resistor which dissipates or consumes the regenerated power. When the regenerated power being consumed by the resistor is detected to exceed a predetermined value, the excess regenerated power is returned to the A.C. source through a regenerative inverter.
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Citations
5 Claims
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1. In an elevator controlling apparatus in which an alternating current supplied from a power source is converted into a direct current by a converter, and said direct current is further converted into a variable-voltage and variable-frequency alternating current for controlling a hoist motor,
the improvement comprising: -
regenerated power detecting means for producing a first signal when said hoist motor is regenerating electric power; resistor means, connected to the direct current side of the converter, for consuming the regenerated power in response to said first signal; consumed power detecting means, coupled to said resistor means, for detecting the amount of the regenerated power being consumed by said resistor means and for producing a second signal when said amount is in excess of a predetermined value; and regenerative inverter means, actuated in response to said second signal, for returning the excess regenerated power to said power source. - View Dependent Claims (2, 3, 4, 5)
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Specification