State-space approach controller design for PLC-based PWM-driven variable speed drive

Intelligent control has contributed great benefits to industry in terms of increasing efficiency and productivity of industrial processes. Programmable Logic Controller (PLC) - based controller is one of the control device used in industrial automation drive applications, the important aspect is to control speed of an induction motor in the presence of variable load. The plant model in this project is developed using MATLAB/Simulink and the aim is to simulate and analyse the appropriate control technique suitable for implementation onto the PLC to perform real-time implementation of the VSD (variable speed drive) control. This paper presents the work conducted in analyzing, evaluating and improving a PLC-based intelligent controller for a Pulse Width Modulation, (PWM)-Driven VSD of an induction motor by using state space control method, focusing on the low speed response. The results show that it is possible to archive a good control at low speed.