Patent ID: 8172042

Claim:
A power system for operating a plurality of hoist motors, each hoist motor for controlling movement of one of a plurality of elevators, the power system comprising: a power bus; a converter connected across the power bus for converting alternating current (AC) power from an AC power source to direct current (DC) power and delivering the DC power to the power bus; a plurality of inverters connected across the power bus, each inverter connected to a hoist motor and operable to drive the hoist motor when the hoist motor is motoring by converting the DC power from the power bus into AC power, each inverter further operable to convert AC power produced by the hoist motor when the motor is generating to DC power and to deliver the DC power to the power bus; and a controller for managing power on the power bus by controlling operation of the converter and the inverters to drive a motoring hoist motor with power provided to the power bus by the converter and generating hoist motors, wherein the controller staggers dispatching of the plurality of elevators to prevent overlapping current transients in the hoist motors which occur upon starting and accelerating an elevator.