A four quadrant adjustable speed drive for series wound DC motors

Abstract

The aim of this research project is to design and test a motor speed controller for use in medium sized electric vehicles such as golf carts and forklift trucks. The adjustable speed drive provides control of a series motor in four modes; forward motoring, forward regeneration (i.e. braking), reverse motoring and reverse regeneration. A low-cost design approach was taken, with a microcontroller forming the heart of the design. Most of the driver's features are implemented in software. Power stage design was also considered, and a suitable power electronic circuit to interface to the control system was designed.