An elevator is a platform, either open or enclosed, used for lifting people or
freight to upper floors within a building. Elevators are a standard part of any tall
commercial or residential building. Mid speed elevators are commonly used in
various mid-rise buildings today.
In this paper, a new type of gear traction machine drive system with a
permanent-magnet (PM) DC motor for mid-rise and mid-speed elevators is
presented. This application of PM motor to the elevator traction machine enables
several improvements including higher efficiency, greater ride comfort, and
miniaturization and so on.
The ideal elevator drive at larger horsepower levels should have efficient
power conversion, regeneration, low harmonic distortion, and near unity power
factor at the utility power lines. Therefore, voltage-fed 3-phase PWM rectifier is
adopted so that DC bus voltage regulation, bi-directional power flow and
controllable power factor with reduced input current harmonics are possible.