JIC_V2_N3_RP4 Sastry D.V.L.N. B. Anil Kumar P. Kameswara Rao G.S.S.S.S.V. Krishna Mohan Journal on Instrumentation & Control Engineering 2321 – 1148 2 3 19 24 Multi capacity tank system, Fractional Order PID controller, MATLAB tool A multi tank level control system is an example of interacting systems. In this paper, the authors considered two first order systems connected in series, one rectangular tank which has inflow of liquid into the tank and out flow. The outflow of first tank is the inflow for second tank through a control valve. The control System is intended to maintain the level of liquid in the second tank at some predefined value irrespective of changes of inflow to the first tank. Fractional Order PID (FOPID) controller is a powerful controllers used in process industries to regulate and control process variables. The errors of the process variables are minimized proportionally, integrally and derivatively. Fractional Order PID controller gives better results for changes in set point and disturbance rejections. The change in inflow or changes in predefined values are treated as disturbances to the process. According to these disturbances, they need to implement better tuning algorithms to Fractional Order PID controllers. In this paper, they implemented different Fractional Order PID control algorithms on a multi tank level control System and their responses are observed and also compared with Conventional PID controllers. May - July 2014 Copyright © 2014 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=3058