This article a secondary controller with PDIC cum FLC for multi area hydro thermal model with multi source. Here, two control areas are connected via. tie line and also, every area consists of  hydro and thermal power system. The traditional controllers are non-capable of manipulating the frequency gap as well as the power oscillation of it at load variable conditions. In order to stabilize the frequency deviation and improve the dynamic performance of multi area multi source hydro thermal system, PDIC along with FLC has been developed.