A new configuration of drive system for high speed gearless elevator

In this paper, a new type of gearless traction machine drive system with a permanent-magnet (PM) motor for high speed elevators is presented. This application of a PM motor to the elevator traction machine enables several improvements including higher efficiency, greater ride comfort, and miniaturization and so on. A voltage-fed 3-phase PWM rectifier is also adopted so that DC bus voltage regulation, bi-directional power flow and controllable power factor with reduced input current harmonics are possible. To guarantee reliability of the whole system, the RC terminator at the motor side is designed for decreasing d/spl nu//dt ratio at motor terminal and then preventing insulation failure of the motor. Some experimental results of 240 m/min operation are given to verify the effectiveness of the proposed scheme.