1.Key Laboratory of Control of Power Transmission and Conversion, Ministry of Education (Shanghai Jiao Tong University), Shanghai 200240, China;2.NARI Technology Co., Ltd., Nanjing 211106, China;3.Electric Power Research Institute of State Grid Tianjin Electric Power Company, Tianjin 300384, China
Quantity regulation is a basic regulation mode of district heating networks. First, aiming at the characteristics of the quantity regulation that the flow is variable and in the turbulent resistance square area, a second-order cone relaxation method for pressure drop of hydraulic branches is proposed, and a penalty cost term is introduced to ensure exact relaxation. Second, according to the characteristics of the stable thermal condition of quantity regulation, a equivalent heat loss method of thermal branches is proposed. The heat loss of the pipeline is equivalent to the load to form a lossless pipeline, which realizes the independent analysis of hydraulic and thermal models. Then, combined with the branch flow model of the distribution network, a joint power flow model of the district heat-electric system is built. Furthermore, a joint optimal power flow model with the form of convex-concave programming for the district heat-electric system is established. Finally, the optimization model is transformed into a second-order cone programming problem and solved sequentially. Simulation cases show that compared with the non-convex accurate model, the proposed method retains a high solution accuracy, improves the solving speed significantly, and can obtain the global optimal solution.
This work is supported by National Key R&D Program of China (No. 2018YFB0905000) and State Grid Corporation of China (No. SGTJDK00DWJS1800232).
|||HAN He, ZHANG Peichao, DU Wei, et al. Joint Optimal Power Flow of District Heat-Electric System in Quantity Regulation Mode[J]. Automation of Electric Power Systems,2021,45(2):30-36. DOI:10.7500/AEPS20200707003|