Environmentally constrained economic dispatch using the LaGrangian relaxation method

This paper presents a general formulation of the environmentally constrained economic dispatch (ECED) problem based on the requirements of Clean Air Act Amendments of 1990 and others which may be imposed by local air quality regulations. The formulation considers multiple NO_x constraints and incorporates the utilization of the affected units (those named in the legislation) along with SO₂ constraints. It also proposes a new algorithm to solve the problem for large power systems. This algorithm has the ability to handle a large number of various types of linear and nonlinear environmental constraints. It is reliable, and viable for both offline and online applications. Test results on a large size power system demonstrate the possible savings which can be realized by using the algorithm. Details of the problem formulation and the solution technique are given in the paper