Design, implementation, and simulation of a PLC based speed controller using fuzzy logic

Successful implementation of the fuzzy method for speed control of a motor/generator set using a general-purpose programmable logic controller (PLC) is demonstrated in this paper. Speed control of DC motors via a changing armature voltage is a common practice throughout industry. In addition, general-purpose PLCs are the most common controllers utilized in the control of power plants and industrial plants. However, this work suggests a method for increasing the utilization level of an existing general-purpose PLC. In effect, the PLC is requested to perform the additional task of speed control using the elegant and effective fuzzy scheme. With a control scheme based on fuzzy methods, the speed control algorithm was accomplished from within the standard PLC ladder-logic. In addition, simulations were performed for a speed governor for a typical 11 MW steam turbine.