Assessment of available transfer capability for Indian power system in combined economic emission environment

This paper describes the assessment of available transfer capability (ATC) with capacity benefit and transmission reliability margins of practical power systems in combined economic emission despatch (CEED) environment. ATC is a measure of unutilized capability of transmission system subjected to wheeling transactions without violating transmission constraints at a given time and load. In this paper, capacity benefit margin (CBM) is incorporated in the test systems by reserving powers in transmission Jines. The transmission reliability margin (TRM) is implemented by making a generator out at a lime. GEED problem is obtained by considering both the economy and emission objectives. In the proposed approach, Newton Raphson method and evolutionary programming (EP) algorithm have been used for power flow and combined economic emission despatch respectively. This bi-objective GEED problem is converted into single objective function using price penalty factor approach. A novel modified price penalty factor is proposed in this paper to solve the GEED probfem. A non-linear scaling factor is also included in EP algorithm to improve the convergence performance. Assessment of ATG in combined economic emission environment has been tested on Indian utifity-62 bus system with line flow constraints. Simultaneous bilateral and multilateral wheeling transactions have been carried out in the test system for the assessment of ATG. The solutions obtained are quite encouraging and useful in the present deregulated environment.