Simulation Package System Design to Analysis and Control A distillation Column Using Frequency Response Method

 Because of the practical importance of analyzing and controlling the systems arises the need to study the frequency response analysis for any system of several industrial plants. The frequency response used for the studies of dynamic characteristics of chemical processes and control loops in the present work. The process control implemented for different control strategies and compare between them by using frequency response techniques. Frequency response methods also give transient response information.By defining such frequency response quantities as gain margin and phase margin, the transient response can be analyzed. Special software was constructed and designed for the purpose of analyzing the systems using Bode plots technique to determine the characteristics, which also used as interface control to perform the transient response; this system was given the abbreviation IFRA (Interface for Frequency Response Analysis). In this work, using VISUAL BASIC 6.0  and MATLAB  programs to studying and analyze the system by Bode plots, which is represents a method to form the frequency response, which is used to analyze the system and to determine 6.5 its characteristics such as stability or steady-state error characteristics. In this work we presents dynamic analysis of the distillation column,which is Multi-input Multi-output (MIMO) system by using different control strategies such as feedback loops with P, PI, PID-controller or decoupling also with different controllers. Also, using one closed-loop with different controllers and the other loop is open. Other analysis tools relate the closed-loop frequency response such as peak and bandwidth to the transient response. In additional methods, using graphic aid in order to obtain the closed-loop frequency response from the open-loop frequency response. By superimposing the open-loop frequency response over the Nichols chart, to obtain the closed-loop frequency response and then analyze for transient response. Also we describe the effect for step changes in the manipulated variables
on the response of the system. In this work, we use the relative gain array method to find the interaction between loops and then using the decouplers to eliminate this interacting, and compare the system with and without time delay and knowing its characteristics.