Allocating the cost of transient stability constraint relief in bilateral electricity markets

In this study, the issue of allocating the cost of transient stability relief in a bilateral electricity market is investigated. The results of a constrained generation scheduling problem can be utilised in two ways to price the cost of a constraint. In the first method, which is the basis of nodal pricing, the Lagrange multipliers of the nodal power balance constraint are used as the price of electricity at various buses. In the second method, which is used in this study, the constraint relief scheme is based on a bid-based adjustment market of increments and decrements offered by generators to be involved in the constraint relief process. In the scheme used in this study, the cost of transient stability relief is first allocated to the individual constraints by different methods and the allocated costs are then allocated to the transactions in proportion to the degree of involvement in that constraint. Three methods are proposed and discussed for allocation of cost to the constraints and the results are compared and commented. The transient energy function (TEF) method is used to calculate the contribution of transactions in the constraints.