Demand response(DR)and wind power are beneficial to low-carbon electricity to deal with energy and environmental problems.However,the uncertain wind power generation(WG)which has anti-peaking characteristic would be h...Demand response(DR)and wind power are beneficial to low-carbon electricity to deal with energy and environmental problems.However,the uncertain wind power generation(WG)which has anti-peaking characteristic would be hard to exert its ability in carbon reduction.This paper introduces DR into traditional unit commitment(UC)strategy and proposes a multi-objective day-ahead optimal scheduling model for wind farm integrated power systems,since incentive-based DR can accommodate excess wind power and can be used as a source of system spinning reserve to alleviate generation side reserve pressure during both peak and valley load periods.Firstly,net load curve is obtained by forecasting load and wind power output.Then,considering the behavior of DR,a day-ahead optimal dispatching scheme is proposed with objectives of minimum generating cost and carbon emission.Non-dominated sorting genetic algorithm-II(NSGA-II)and satisfaction-maximizing method are adopted to solve the multi-objective model with Pareto fronts and eclectic decision obtained.Finally,a case study is carried out to demonstrate that the approach can achieve economic and environmental aims and DR can help to accommodate the wind power.展开更多
基于鲁棒优化理论的机组组合问题存在解的保守性较大,计算过程复杂等缺点。该文基于改进轻鲁棒模型,建立了新型的风–火电机组组合新模型,并推导出其混合整数线性规划(mixed integer linear programming,MILP)对应式。该模型通过弃风变...基于鲁棒优化理论的机组组合问题存在解的保守性较大,计算过程复杂等缺点。该文基于改进轻鲁棒模型,建立了新型的风–火电机组组合新模型,并推导出其混合整数线性规划(mixed integer linear programming,MILP)对应式。该模型通过弃风变量实现了风电出力调度,并通过设备的防止过度过载和连续过载约束,实现了对设备短时过载能力的安全利用,改善了保守性;所推得的MILP对应式为一个线性确定性优化问题,可以直接求解,不会像其他方法那样因对偶变换产生非线性项而不易求解,所以计算效率明显提高。该文的算例证明了文中所提的ILR-UC模型及其MILP对应式的有效性。展开更多
Unit commitment （UC） is an optimization problem used to determine the operation schedule of the generating units at every hour interval with varying loads under different constraints and environments. Many algorithm...Unit commitment （UC） is an optimization problem used to determine the operation schedule of the generating units at every hour interval with varying loads under different constraints and environments. Many algorithms have been invented in the past five decades for optimization of the UC problem, but still researchers are working in this field to find new hybrid algorithms to make the problem more realistic. The importance of UC is increasing with the constantly varying demands. There- fore, there is an urgent need in the power sector to keep track of the latest methodologies to further optimize the working criterions of the generating units. This paper focuses on providing a clear review of the latest techniques employed in optimizing UC problems for both stochastic and deterministic loads, which has been acquired from many peer reviewed published papers. It has been divided into many sections which include various constraints based on profit, security, emission and time. It emphasizes not only on deregulated and regulated environments but also on renewable energy and distributed generating systems. In terms of contributions, the detailed analysis of all the UC algorithms has been discussed for the benefit of new researchers interested in working in this field.展开更多
The development of renewable energy and the increasing peak-valley difference of load demand lead to an increasing requirement of spinning reserve(SR).However,the traditional operation reliability analysis of power sy...The development of renewable energy and the increasing peak-valley difference of load demand lead to an increasing requirement of spinning reserve(SR).However,the traditional operation reliability analysis of power system mainly focuses on the up SR and neglects the down SR.Therefore,the operation reliability of power system considering the impacts of down SR is investigated in this paper.Firstly,the constraints of down SR are incorporated into the day-ahead unit commitment(UC)model to obtain the generation scheduling and reserve allocation of power systems.Based on the dispatch results of UC model,the re-dispatched energy and load interruption can be determined using optimal power flow(OPF)model in the realtime operation in various contingency states.Operation reliability indices are calculated based on the load curtailment to represent the reliability performances of power systems.The proposed approaches are validated using the modified IEEE reliability test system.Case studies demonstrate that down SR can improve the operation reliability of power systems.展开更多
Unit commitment （UC） problem is one of the most important decision making problems in power system. In this paper the UC problem is solved by considering it as a real time problem by adding stochasticity in the gene...Unit commitment （UC） problem is one of the most important decision making problems in power system. In this paper the UC problem is solved by considering it as a real time problem by adding stochasticity in the generation side because of wind-thermal co-ordination system as well as stochasticity in the load side by incorporating the randomness of the load. The most important issue that needs to be addressed is the achievement of an economic unit commitment solution after solving UC as a real time problem. This paper proposes a hybrid approach to solve the stochastic UC problem considering the volatile nature of wind and formulating the UC problem as a chance constrained problem in which the load is met with high probability over the entire time period.展开更多
Unit commitment(UC), as a typical optimization problem in electric power system, faces new challenges as energy saving and emission reduction get more and more important in the way to a more environmentally friendly s...Unit commitment(UC), as a typical optimization problem in electric power system, faces new challenges as energy saving and emission reduction get more and more important in the way to a more environmentally friendly society. To meet these challenges, we propose a UC model considering energy saving and emission reduction. By using real-number coding method, swap-window and hill-climbing operators, we present an improved real-coded genetic algorithm(IRGA) for UC. Compared with other algorithms approach to the proposed UC problem, the IRGA solution shows an improvement in effectiveness and computational time.展开更多
基金This work is supported by National Natural Science Foundation of China(No.51277015).
文摘Demand response(DR)and wind power are beneficial to low-carbon electricity to deal with energy and environmental problems.However,the uncertain wind power generation(WG)which has anti-peaking characteristic would be hard to exert its ability in carbon reduction.This paper introduces DR into traditional unit commitment(UC)strategy and proposes a multi-objective day-ahead optimal scheduling model for wind farm integrated power systems,since incentive-based DR can accommodate excess wind power and can be used as a source of system spinning reserve to alleviate generation side reserve pressure during both peak and valley load periods.Firstly,net load curve is obtained by forecasting load and wind power output.Then,considering the behavior of DR,a day-ahead optimal dispatching scheme is proposed with objectives of minimum generating cost and carbon emission.Non-dominated sorting genetic algorithm-II(NSGA-II)and satisfaction-maximizing method are adopted to solve the multi-objective model with Pareto fronts and eclectic decision obtained.Finally,a case study is carried out to demonstrate that the approach can achieve economic and environmental aims and DR can help to accommodate the wind power.
文摘基于鲁棒优化理论的机组组合问题存在解的保守性较大,计算过程复杂等缺点。该文基于改进轻鲁棒模型,建立了新型的风–火电机组组合新模型,并推导出其混合整数线性规划(mixed integer linear programming,MILP)对应式。该模型通过弃风变量实现了风电出力调度,并通过设备的防止过度过载和连续过载约束,实现了对设备短时过载能力的安全利用,改善了保守性;所推得的MILP对应式为一个线性确定性优化问题,可以直接求解,不会像其他方法那样因对偶变换产生非线性项而不易求解,所以计算效率明显提高。该文的算例证明了文中所提的ILR-UC模型及其MILP对应式的有效性。
文摘Unit commitment （UC） is an optimization problem used to determine the operation schedule of the generating units at every hour interval with varying loads under different constraints and environments. Many algorithms have been invented in the past five decades for optimization of the UC problem, but still researchers are working in this field to find new hybrid algorithms to make the problem more realistic. The importance of UC is increasing with the constantly varying demands. There- fore, there is an urgent need in the power sector to keep track of the latest methodologies to further optimize the working criterions of the generating units. This paper focuses on providing a clear review of the latest techniques employed in optimizing UC problems for both stochastic and deterministic loads, which has been acquired from many peer reviewed published papers. It has been divided into many sections which include various constraints based on profit, security, emission and time. It emphasizes not only on deregulated and regulated environments but also on renewable energy and distributed generating systems. In terms of contributions, the detailed analysis of all the UC algorithms has been discussed for the benefit of new researchers interested in working in this field.
基金supported by the National Natural Science Foundation of China(No.51577167)
文摘The development of renewable energy and the increasing peak-valley difference of load demand lead to an increasing requirement of spinning reserve(SR).However,the traditional operation reliability analysis of power system mainly focuses on the up SR and neglects the down SR.Therefore,the operation reliability of power system considering the impacts of down SR is investigated in this paper.Firstly,the constraints of down SR are incorporated into the day-ahead unit commitment(UC)model to obtain the generation scheduling and reserve allocation of power systems.Based on the dispatch results of UC model,the re-dispatched energy and load interruption can be determined using optimal power flow(OPF)model in the realtime operation in various contingency states.Operation reliability indices are calculated based on the load curtailment to represent the reliability performances of power systems.The proposed approaches are validated using the modified IEEE reliability test system.Case studies demonstrate that down SR can improve the operation reliability of power systems.
文摘Unit commitment （UC） problem is one of the most important decision making problems in power system. In this paper the UC problem is solved by considering it as a real time problem by adding stochasticity in the generation side because of wind-thermal co-ordination system as well as stochasticity in the load side by incorporating the randomness of the load. The most important issue that needs to be addressed is the achievement of an economic unit commitment solution after solving UC as a real time problem. This paper proposes a hybrid approach to solve the stochastic UC problem considering the volatile nature of wind and formulating the UC problem as a chance constrained problem in which the load is met with high probability over the entire time period.
基金the National Natural Science Foundation of China(Nos.61004088 and 61374160)
文摘Unit commitment(UC), as a typical optimization problem in electric power system, faces new challenges as energy saving and emission reduction get more and more important in the way to a more environmentally friendly society. To meet these challenges, we propose a UC model considering energy saving and emission reduction. By using real-number coding method, swap-window and hill-climbing operators, we present an improved real-coded genetic algorithm(IRGA) for UC. Compared with other algorithms approach to the proposed UC problem, the IRGA solution shows an improvement in effectiveness and computational time.
