Transmission constrained unit commitment in competitive environment by enhanced adaptive lagrangian relaxation

Abstract

This work proposes an enhanced adaptive Lagrangian relaxation (ELR) for centralized dispatch of transmission constrained unit commitment (TCUC) problem in competitive environment. ELR minimizes the consumer payment rather than the total supply cost subject to the power balance, spinning reserve, transmission lines, and generator operating constraints. ELR algorithm is enhanced by new initialization of Lagrangian multipliers and adaptive adjustment of Lagrangian multipliers. The transmission constrained economic dispatch is solved by quadratic programming. If congestion exists, the alleviating congestion index is proposed for congestion management. Moreover, the side payment to each generator is proposed to ensure payment adequacy without resulting in excessive system marginal price, leading to a lower consumer payment. The ELR is tested on the IEEE 24 bus reliability test system.