Enhancing unit commitment in power systems: A piecewise-linear approach for optimal scheduling and environmental sustainability

The Unit Commitment (UC) presents significant challenges in power systems, primarily focusing on scheduling generation units to meet demand while minimizing costs. Traditional methods often struggle with the non-linearity of generator cost functions and operational constraints, resulting in inefficiencies. This research introduces a novel methodology utilizing a piecewise-linear transformation of quadratic cost functions, enhancing computational efficiency and accuracy. By incorporating steam valve loading effects (VLEs), the model offers a more realistic representation of generator behavior, addressing critical operational constraints frequently neglected in conventional approaches. Furthermore, environmental considerations, particularly pollution impacts, are emphasized as vital constraints, reflecting the increasing importance of sustainability in power systems. The proposed two-step approach begins by establishing an initial commitment schedule without minimum up and down time constraints, facilitating a quicker solution process. This schedule is then refined to comply with these constraints, ensuring reliability and operational integrity. The results demonstrate a significant enhancement in cost efficiency compared to existing methods. For example, with a unit size of 10, the proposed method yielded a total cost of 592,606, outperforming genetic algorithm (GA) at 595,569 and particle swarm optimization (PSO) at 603,318. This trend continues across larger unit sizes, achieving a notable reduction of 34,409 at 100 units compared to the best alternative. Overall, the findings underscore the robustness and effectiveness of this approach in advancing power system optimization strategies while maintaining stability across various unit sizes. • Unit Commitment (UC) optimizes generation scheduling to minimize costs. • Novel piecewise-linear transformation enhances cost function efficiency. • Incorporating steam valve loading improves generator behavior representation. • Environmental impacts are prioritized as vital constraints in scheduling. • Two-step approach refines schedules for reliability and regulatory compliance.