Method and system for stopping elevators using AC motors driven by static frequency converters
AssigneeDanfoss A/S
InventorsDetlev Abraham, Hans-Josef Mennen
Life of this patent
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Abstract
The invention relates to methods for stopping elevators especially when using at least one three-phase motor operated by a static frequency converter. According to the invention, a brake relay controls the brake of the motor such that releasing of the brake relay causes the motor to be decelerated while the brake relay is coupled to a protective circuit in such a way that the control pulses required for generating the driving motor field are safely blocked when the brake relay is released.
Claims8
A method for stopping elevators by using at least one AC motor driven by a static frequency converter, in which a brake relay controls the brake of the motor so that de-energizing the brake relay will brake the motor, the brake relay being connected with a safety switch in such a manner that de-energizing the brake relay will reliably block the control impulses required for generating the driving motor field.
Dependencies are inferred from the claim text.