Convex Hull Based Economic Operating Region for Power Grids Considering Uncertainties of Renewable Energy Sources

The increasing integration of renewable energy sources(RESs)presents significant challenges for the safe and economical operation of power grids.Addressing the critical need to assess the effect of RES uncertainties on optimal scheduling schemes(OSSs),this paper introduces a convex hull based economic operating region(CH-EOR)for power grids.The CHEOR is mathematically defined to delineate the impact of RES uncertainties on power grid operations.We propose a novel approach for generating the CH-EOR,enhanced by a big-M preprocessing method to improve the computational efficiency.Performed on four test systems,the proposed big-M preprocessing method demonstrates notable advancements:a reduction in average operating costs by over 10%compared with the box-constrained operating region(BC-OR)derived from robust optimization.Furthermore,the CH-EOR occupies less than 11.79%of the generators'adjustable region(GAR).Most significantly,after applying the proposed big-M preprocessing method,the computational efficiency is improved over 17 times compared with the traditional big-M method.

Fully Distributed Risk-based Robust Reserve Scheduling for Bulk Hybrid AC-DC Systems

To enhance the cost-effectiveness of bulk hybrid AC-DC power systems and promote wind consumption,this paper proposes a two-stage risk-based robust reserve scheduling(RRRS)model.Different from traditional robust optimization,the proposed model applies an adjustable uncertainty set rather than a fixed one.Thereby,the operational risk is optimized together with the dispatch schedules,with a reasonable admissible region of wind power obtained correspondingly.In addition,both the operational base point and adjustment capacity of tielines are optimized in the RRRS model,which enables reserve sharing among the connected areas to handle the significant wind uncertainties.Based on the alternating direction method of multipliers(ADMM),a fully distributed framework is presented to solve the RRRS model in a distributed way.A dynamic penalty factor adjustment strategy(DPA)is also developed and applied to enhance its convergence properties.Since only limited information needs to be exchanged during the solution process,the communication burden is reduced and regional information is protected.Case studies on the 2-area 12-bus system and 3-area 354-bus system illustrate the effectiveness of the proposed model and approach.