Optimum Controller Settings for PWM Mode Control Systems

摘要

The application of Pulse Width Modulation (PWM) control scheme with suitable final control element has been increasing in chemical and related industries during the past two decades due to its cost-effectiveness and many inherent operational advantages. Yet, there seems to be a very little effort for establishing guidelines for obtaining optimum performance out of such systems.In the present study, setting formulate have been developed to obtain minimum ITAE value of close loop response for the three parameters of PID controller. The process is assumed to have a first order plus dead time (FOPDT) dynamics, and the final control element parameters as variables. As indigenously developed linear search optimization routine OPTIM1 has been employed for establishing the minimum ITAE as the objective function. The minimum ITAE is found with respect to the close loop step response by adjusting the three controller parameters for a given set of process and final control element parameters. Thus, controller parameters for minimum ITAE are found for a number of process parameter values covering the practical application range. A set of formulate for controller parameters is found by Least Square Method. To compare performance, ITAE values obtained by using guidelines of earlier studies are compared with those of the present study.