Economic Power Dispatch with Line Security Limits

A practical and efficient method is presented for the economic dispatch of generation with explicit recognition of line security limits. The linearized or dc loadflow approximation is used to formulate the line security limits as linear inequality constraints on the generator outputs. The optimization problem is solved by the method of gradient projection. The proposed method does not require a great deal more computation time or system-state information than the established method of dispatch which is unable to recognize line security limits. In consequence, the method gives power control centers with only moderate sized dispatch computers the potential for recognizing line security limits in their economic dispatch and thus obtaining improved security and economy in system operation.