A motor driving controller suitable for elevators

An induction motor driving controller which can improve the performance of elevators is studied. The controller has three features. Firstly, it has an energy-saving control by which the induction motor stably generates motor torque at the maximum efficiency, regardless of the number of passengers boarding the car, even if both acceleration from a standstill and deceleration from steady-state are done for any elevator. Secondly, it can suppress vertical vibrations of elevators while performing energy-saving control. Thirdly, it ensures good performance of elevators even when the source voltage is reduced due to an overload on the source sides. The controller is judged suitable for the drive system of elevators on the basis of simulations and experiments.