Patent ID: 7882937
Filing Date: 2011-02-08
Classification: B66B,Y02B

Abstract:
1. An elevating machine control apparatus comprising an inverter controlled according to a torque command provided from a difference signal between a predetermined speed command signal and a speed signal corresponding to an actual traveling speed, an AC motor connected to the inverter and driven by an AC power of variable voltage and variable frequency, and a power generation braking resistor energized to apply a brake by on/off control of a regenerating semiconductor device during regenerative operation of the AC motor, wherein the elevating machine control apparatus determines that the regenerating semiconductor device is in failure when it is detected that the DC stage voltage of the inverter has a ripple quantity of a set value or more while the elevating machine is being stopped, and prohibits the elevating machine from starting operating and interrupts power supply to the power generation braking resistor.