PLC-Based Speed Control of DC Motor

In this paper, a simplified approach for speed control of a separately excited DC motor using programmable logic controller (PLC) is presented. This approach is based on providing a variable dc voltage to armature circuit of dc motor from a fixed dc supply voltage via a PLC which is used as a dc/dc chopper. Pang-Pang control method is used for switching on or off power to dc motor (armature circuit) depending on the reference (command) speed. It is easy, fast and effective by this method of control to vary motor speed from 0 to 100% of rated speed. The proposed system is suitable for different industrial applications such as subway cars, trolley buses, or battery-operated vehicles