M. Murali

A comparison of embedded cost based transmission pricing methods

In the restructured power market, it is necessary to develop an appropriate pricing scheme that can provide the useful economic information to market participants, such as generation, transmission companies and customers. Proper pricing method is needed for transmission network to ensure reliability and secure operation of power system. Accurately estimating and allocating the transmission cost in the transmission pricing scheme still remains challenging task. This paper gives an overview of different costs incurred in transmission transaction, types of transmission transactions and the transmission pricing methodologies. Embedded as well as Incremental cost methods are explained. It mainly focussed on determining the embedded transmission cost by various methods and compared the results for 6bus, IEEE 14bus and RTS 24 bus systems.

Short-range fixed head hydrothermal scheduling using Fast genetic algorithm

This paper presents a Fast genetic algorithm for solving Hydrothermal scheduling (HTS) problem. Genetic Algorithms (GAs) perform powerful global searches, but their long computation times, put a limitation when solving large scale optimization problems. The present paper describes a Fast GA (FGA) to overcome this limitation, by starting with random solutions within the search space and narrowing down the search space by considering the minimum and maximum errors of the population members. Since the search space is restricted to a small region within the available search space the algorithm works very fast. This algorithm reduces the computational burden and number of generations to converge. The proposed algorithm has been demonstrated for HTS of various combinations of Hydro thermal systems. In all the cases Fast GA shows reliable convergence. The final results obtained using Fast GA are compared with simple (conventional) GA and found to be encouraging.

LMP based electricity market simulation using genetic algorithm

In restructured electricity markets, an effective transmission pricing method is required to address transmission issues and to generate correct economic signals. Transmission line constraints can result in variations in energy prices throughout the network. These prices depend on generator bids, load levels and transmission network limitations. Locational Marginal Pricing (LMP) is a dominant approach in energy market operation and planning to identify nodal prices and manage transmission congestion. This paper presents a GA based security constrained economic dispatch (SCED) approach to evaluate LMPs at all buses while minimizing total system fuel cost for a constrained transmission system, with and without considering system losses. The proposed GA based SCED approach is applied on IEEE 14 bus, 75 bus Indian power system and New England 39 bus system. The results obtained are compared with conventional Linear Programming based DCOPF using Power World Simulator. Both fixed and linear bids are considered for generators. The load is assumed to be inelastic. The proposed GA based SCED for LMP calculation is proved to be very simple, reliable and efficient in all the cases studied. Further, the optimal redispatch of generators using GA leads to overall reduction in generation fuel cost.

Aumann Shapley Method for Congestion Cost Allocation in Multilateral Transactions Framework of Restructured Power Market

Deregulation of Electricity market has not only led to increase in competition among generators, but also reduced electricity prices. It has introduced several issues in the market; two of them are congestion management and market power. Due to open transmission access all the participants have equal right to access transmission network. However, they have to bear the costs incurred to accommodate their transaction. The cost allocation is still a problem to be tackled efficiently. The prevailing problem is how to allocate the congestion cost among the market participants. An efficient and fair allocation of congestion cost would result in smooth operation of transmission system. It also helps in tackling congestion and market power. This paper proposes a novel approach using Aumann Shapley (AS) method of game theory for congestion cost allocation in a deregulated electricity market. The results obtained using proposed method are compared with uplift and nodal pricing methods for IEEE 14 bus system, New En...

Distribution of loss cost using proportional nucleolus method in competitive power markets

The present deregulated electricity industry has evolved into a distributed and competitive industry in which market forces drive the price of electricity and reduce the net cost of electricity. However the competitions in these markets require identification of the use of transmission networks, mainly the participation of utilities in losses caused in the transmission lines. This is because the consumers pay for their actual consumption where as generators are paid for their generation plus losses. Hence the loss cost allocation is of great importance as it should be allocated efficiently to both consumers and producers (both network users). Thus loss cost allocation in competitive electricity market requires a fair and efficient method with right economic signals. In this paper, loss cost allocation methodologies are presented in multilateral transaction frame work. Methodologies in cooperative game theory such as nucleolus, shapely and proportional nucleolus are presented. These are compared with conventional methods for loss allocation. Among all the methods presented, the proportional nucleolus is proved to be the efficient method with right economic signals. All the methods are implemented and results are compared for IEEE 14 bus, New England 39 bus and 75 bus Indian Power System.