Three=phase traction motor control system - has two running speeds and regenerative braking is achieved between high and low speeds

摘要

The three phase traction system with a single motor (M) is designed to run at two set speeds, one high speed for normal travel and a much lower speed. When the vehicle is to be braked from the cruising speed the control is set for the lower speed so that a regenerative braking is obtained, after which the normal friction brakes are applied. The regenerative braking is controlled by a simple comparator circuit to reach a set lower speed, after which the friction brakes are progressively brought into action, and the drive is discontinued. The system allows a three phase traction vehicle to be stopped in a controlled distance, especially for remote control.