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Wang J.,Dalian University of Technology | Liao S.,Dalian University of Technology | Cheng C.,Dalian University of Technology | Cai H.,Yunnan Power Dispatching Center
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2011

This paper presents a hybrid search algorithm for the optimization problem of medium-term thermal power boot. The algorithm uses actual demand as the point of departure and equal capacity utilization hours of all thermal power plants as the goal. The algorithm consists of two steps. In the first step we get initial solution by heuristics. In the second step vertical search and lateral search are combined to find global optimal solution. At this step, vertical search is based on progressive optimality algorithm and lateral search is used to jump out of local optimization. The algorithm has the merits with simple process, quick convergence and avoiding local optimum. The actual data is used in a system with 9 power stations and 27 units to verify the algorithm. The results demonstrate the real-time processing capacity and accuracy can satisfy the actual demand. © 2011 Chin. Soc. for Elec. Eng. Source


Liao S.,Dalian University of Technology | Cheng C.,Dalian University of Technology | Wang J.,Dalian University of Technology | Cai H.,Yunnan Power Dispatching Center | Deng G.,Dalian University of Technology
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2010

According to the characteristics of medium-term thermal-unit commitments optimization, a mathematical model considering both the traditional mode and energy-saving principle is proposed, and an improved progressive optimality algorithm (IPOA) is adopted to solve the model. The algorithm takes the initial feasible solution from heuristics search as the basis, and the progressive optimality algorithm(POA) is adopted to improve it. At the same time, the strategies for system operating capacity equalization and single station operating peak combination are adopted to move the target solution from the boundary constraints along the target isopleths into the feasible solution's interior to provide search space for iterative loop and overcome the disadvantage of POA that is apt to fall into local optimum. In the process of algorithm implementation, the local verifying tactics are adopted to simply judge the constraints of peak and valley duration of unit commitment capacity to reduce the calculation cost. Case studies with Yunnan power grid are given to verify the proposed model and algorithm. © 2010 State Grid Electric Power Research Institute Press. Source


Chen F.,Dalian University of Technology | Li G.,Dalian University of Technology | Cheng C.,Dalian University of Technology | Li X.,Yunnan Power Dispatching Center
World Environmental and Water Resources Congress 2015: Floods, Droughts, and Ecosystems - Proceedings of the 2015 World Environmental and Water Resources Congress | Year: 2015

Southwestern China has experienced an imbalance growth between power supply and load demand for last decade. Meanwhile the construction of transmission lines is far behind the power supply growth. They together contribute to multistage congestion problem which threaten the reliability and stability of the power grid in wet season. This paper presents a method for coordinating the generation schedules of hydropower system of a municipal power grid. The objective is to maximize the total energy consumed on condition that ensuring the reliability and stability of the power grid. This is achieved by conceptualizing power grid as a diagraph based on the graph theory. Depth-First-Search (DFS) and transmission-line security checking are used to analyze topology relations of the power grid and flag overload transmission lines which violate the electric power transmission restrictions. A multistage congestion coordination strategy is introduced to iteratively coordinate the initial generation schedules of power supplies sharing overload transmission lines. The proposed method has been implemented to the hydropower system of Yunnan Power Grid in since 2014. The case results show that the method is feasible and practical. © 2015 ASCE. Source


Gang L.,Dalian University of Technology | Benxi L.,Dalian University of Technology | Shanzong L.,Dalian University of Technology | Chuntian C.,Dalian University of Technology | Xiufeng L.,Yunnan Power Dispatching Center
World Environmental and Water Resources Congress 2013: Showcasing the Future - Proceedings of the 2013 Congress | Year: 2013

As one of the most important renewable resources, small hydropower is also an emphasized project of the Clean Development Mechanism (CDM), which has been greatly developed and of great importance to alleviate the energy crisis resulting from the rapid economic growth of China in the past few decades. The impact on power grid is more and more obvious as most small hydropower plants operate on a river run-off system and generation output variation is very large between wet period and dry period. In the meanwhile, the operation and management of small hydropower in China have many outstanding problems due to the history and other reasons. Taking Yunnan power grid as the background, in this paper attempt has been made to explain the influence on safety and stability of power grid after large-scale small hydropower in operation. First, detailed description of the situation of small hydropower in Yunnan power grid. Second, combined with the actual circumstances, analysis of the problems and challenges that the power grid faces is presented. Finally the corresponding solution measures are put forward. © 2013 American Society of Civil Engineers. Source


Li S.,Dalian University of Technology | Liao S.,Dalian University of Technology | Li G.,Dalian University of Technology | Cheng C.,Dalian University of Technology | And 2 more authors.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2012

This paper presented a province-district integrated generation scheduling compilation method for large-scale small hydropower station group. The approach was developed to handle current problems of small hydropower: disorderly management, striking waste of water and seriously abandoned electricity. This proposed method standardized the generation scheduling compilation flow of small hydropower by the idea of hierarchic building and management based on the scheduling relation of small hydropower. The tie-line section security constraint was added into the flow and an adjusting original schedules procedure of overload section was proposed. By the closed-loop mode of reporting proposed generating curves, checking transmission section security, distributing coordinate generating curves, the accuracy of power generation scheduling of small hydropower was increased effectively. The method had been applied to the small hydropower management system of Yunnan power grid. The feasibility and effectiveness of this algorithm has been verified available by the practical engineering. © 2012 Chinese Society for Electrical Engineering. Source

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