Patent ID: 7909143

Claim:
Method for controlling an elevator group when the maximum power consumption is limited, wherein the elevator group comprises at least one elevator and call allocation in the elevator group is controlled by a control system, said method comprising the steps of: considering on the basis of active calls and the states of the elevators at the instant of consideration a possible route alternative for the elevators; defining a cost function containing at least one cost term, each of which comprises a quantity relating to the operation of the elevator system; adding to the cost function a cost term that comprises the instantaneous power consumed by the elevator system; setting a maximum limit for the power; allocating elevators to the calls in such a way that the cost function is minimized and that the set maximum power limit will not be exceeded at any instant of consideration in the route alternative; and giving an elevator allocated to a call a start permission from the control system before departure of the elevator, if taking the said elevator into use will not result in exceeding the set maximum power limit.