智能软开关(soft normally open point,SNOP)是一种取代传统联络开关的新型智能配电装置,SNOP的应用将极大地提高配电系统运行的灵活性和可控性。但考虑到接入和运行成本,未来的配电系统运行可能要面临同时考虑SNOP和联络开关的情形。首...智能软开关(soft normally open point,SNOP)是一种取代传统联络开关的新型智能配电装置,SNOP的应用将极大地提高配电系统运行的灵活性和可控性。但考虑到接入和运行成本,未来的配电系统运行可能要面临同时考虑SNOP和联络开关的情形。首先,研究联络开关和SNOP并存时配电网运行的时序优化模型,该问题在数学上属于混合整数非线性优化问题;进而提出一种基于模拟退火(simulated annealing,SA)和锥优化(conic programming,CP)的混合优化算法进行求解,算法利用SA实现开关状态的快速求解,利用CP实现SNOP传输功率的准确计算,能够实现大规模混合整数非线性优化问题的快速、准确求解,并满足时序优化问题的计算需求。最后,在IEEE 33节点算例上,对所提出的运行优化模型和求解算法进行分析和验证。展开更多
为了解决大规模光伏接入主动配电网后引起的节点电压越限和波动的问题,提出了一种含智能软开关(soft open point,SOP)的主动配电网3阶段鲁棒电压控制(three-stage robust voltage control,TSRVC)方法。该方法的第1阶段考虑了长时间尺度...为了解决大规模光伏接入主动配电网后引起的节点电压越限和波动的问题,提出了一种含智能软开关(soft open point,SOP)的主动配电网3阶段鲁棒电压控制(three-stage robust voltage control,TSRVC)方法。该方法的第1阶段考虑了长时间尺度下光伏出力和负荷的不确定性,对有载调压变压器的分接头位置和电容器组的投切组数进行了鲁棒优化;第2阶段根据光伏和负荷的短期功率预测结果,对各个SOP的有功功率和其电压-无功下垂曲线进行了优化;第3阶段根据节点电压的实时测量值和上一阶段优化得到的电压-无功下垂曲线,动态地调整各个SOP的实时无功功率输出。最后,在改进的IEEE 33节点算例上进行了仿真,结果表明:所提3阶段鲁棒电压控制方法可以充分应对光伏出力和负荷的不确定性,将节点电压有效控制在理想范围内的同时,能够显著降低系统的运行损耗,实现含高渗透率光伏配电网的电压控制。展开更多
To deal with uncertainties of renewable energy,demand and price signals in real-time microgrid operation,this paper proposes a model predictive control strategy for microgrid economic dispatch, where hourly schedule i...To deal with uncertainties of renewable energy,demand and price signals in real-time microgrid operation,this paper proposes a model predictive control strategy for microgrid economic dispatch, where hourly schedule is constantly optimized according to the current system state and latest forecast information. Moreover, implicit network topology of the microgrid and corresponding power flow constraints are considered, which leads to a mixed integer nonlinear optimal power flow problem. Given the non-convexity feature of the original problem, the technique of conic programming is applied to efficiently crack the nut. Simulation results from a reconstructed IEEE-33 bus system and comparisons with the routine day-ahead microgrid schedule sufficiently substantiate the effectiveness of the proposed MPC strategy and the conic programming method.展开更多
针对主动配电系统(active distribution system,ADS)中分布式电源(distributed generation,DG)的间歇性和主动负荷及储能系统(energy storage system,ESS)的可控性特点,基于ADS的最大供电能力(ADS’s total supply capability,ATSC)提...针对主动配电系统(active distribution system,ADS)中分布式电源(distributed generation,DG)的间歇性和主动负荷及储能系统(energy storage system,ESS)的可控性特点,基于ADS的最大供电能力(ADS’s total supply capability,ATSC)提出一种评价ADS安全性的安全等级划分方法。首先,提出了节点多性质的ADS最大供电能力求解模型,引入DG及ESS的相关约束,并将其中的非线性约束转化为旋转锥的笛卡尔乘积约束形式,用锥优化方法进行快速计算。其次,基于静态安全分析定义了安全裕度、主动负荷熵、主动调节率及主动安全度指标,结合失负荷率及越限指标构成评价指标体系,进而提出了ADS安全等级划分方法,并用该方法将ADS划分为5个安全等级。用粒子群算法对主动负荷进行优化并用一致性主动控制方法制定储能系统充放电策略,应用该文提出的评价方法对比优化前后配电网的安全等级情况,验证了所提方法的实用性及有效性。展开更多
In this paper, a new method to address the scheduling problem of a renewable energy community while considering network constraints and users' privacy preservation is proposed. The method decouples the optimizatio...In this paper, a new method to address the scheduling problem of a renewable energy community while considering network constraints and users' privacy preservation is proposed. The method decouples the optimization solution into two interacting procedures: conic projection(CP) and linear programming(LP) optimization. A new optimal CP method is proposed based on local computations and on the calculation of the roots of a fourth-order polynomial for which a closed-form solution is known. Computational tests conducted on both 14-bus and 84-bus distribution networks demonstrate the effectiveness of the proposed method in obtaining the same quality of solutions compared with that by a centralized solver. The proposed method is scalable and has features that can be implemented on microcontrollers since both LP and CP procedures require only simple matrix-vector multiplications.展开更多
Trust region methods are powerful and effective optimization methods. The conic model method is a new type of method with more information available at each iteration than standard quadratic-based methods. The adva...Trust region methods are powerful and effective optimization methods. The conic model method is a new type of method with more information available at each iteration than standard quadratic-based methods. The advantages of the above two methods can be combined to form a more powerful method for constrained optimization. The trust region subproblem of our method is to minimize a conic function subject to the linearized constraints and trust region bound. At the same time, the new algorithm still possesses robust global properties. The global convergence of the new algorithm under standard conditions is established.展开更多
文摘为了解决大规模光伏接入主动配电网后引起的节点电压越限和波动的问题,提出了一种含智能软开关(soft open point,SOP)的主动配电网3阶段鲁棒电压控制(three-stage robust voltage control,TSRVC)方法。该方法的第1阶段考虑了长时间尺度下光伏出力和负荷的不确定性,对有载调压变压器的分接头位置和电容器组的投切组数进行了鲁棒优化;第2阶段根据光伏和负荷的短期功率预测结果,对各个SOP的有功功率和其电压-无功下垂曲线进行了优化;第3阶段根据节点电压的实时测量值和上一阶段优化得到的电压-无功下垂曲线,动态地调整各个SOP的实时无功功率输出。最后,在改进的IEEE 33节点算例上进行了仿真,结果表明:所提3阶段鲁棒电压控制方法可以充分应对光伏出力和负荷的不确定性,将节点电压有效控制在理想范围内的同时,能够显著降低系统的运行损耗,实现含高渗透率光伏配电网的电压控制。
基金supported by the National Natural Science Foundation of China(No.51277170)the National Key Basic Research Program of China(No.2012CB215204)
文摘To deal with uncertainties of renewable energy,demand and price signals in real-time microgrid operation,this paper proposes a model predictive control strategy for microgrid economic dispatch, where hourly schedule is constantly optimized according to the current system state and latest forecast information. Moreover, implicit network topology of the microgrid and corresponding power flow constraints are considered, which leads to a mixed integer nonlinear optimal power flow problem. Given the non-convexity feature of the original problem, the technique of conic programming is applied to efficiently crack the nut. Simulation results from a reconstructed IEEE-33 bus system and comparisons with the routine day-ahead microgrid schedule sufficiently substantiate the effectiveness of the proposed MPC strategy and the conic programming method.
文摘针对主动配电系统(active distribution system,ADS)中分布式电源(distributed generation,DG)的间歇性和主动负荷及储能系统(energy storage system,ESS)的可控性特点,基于ADS的最大供电能力(ADS’s total supply capability,ATSC)提出一种评价ADS安全性的安全等级划分方法。首先,提出了节点多性质的ADS最大供电能力求解模型,引入DG及ESS的相关约束,并将其中的非线性约束转化为旋转锥的笛卡尔乘积约束形式,用锥优化方法进行快速计算。其次,基于静态安全分析定义了安全裕度、主动负荷熵、主动调节率及主动安全度指标,结合失负荷率及越限指标构成评价指标体系,进而提出了ADS安全等级划分方法,并用该方法将ADS划分为5个安全等级。用粒子群算法对主动负荷进行优化并用一致性主动控制方法制定储能系统充放电策略,应用该文提出的评价方法对比优化前后配电网的安全等级情况,验证了所提方法的实用性及有效性。
文摘In this paper, a new method to address the scheduling problem of a renewable energy community while considering network constraints and users' privacy preservation is proposed. The method decouples the optimization solution into two interacting procedures: conic projection(CP) and linear programming(LP) optimization. A new optimal CP method is proposed based on local computations and on the calculation of the roots of a fourth-order polynomial for which a closed-form solution is known. Computational tests conducted on both 14-bus and 84-bus distribution networks demonstrate the effectiveness of the proposed method in obtaining the same quality of solutions compared with that by a centralized solver. The proposed method is scalable and has features that can be implemented on microcontrollers since both LP and CP procedures require only simple matrix-vector multiplications.
文摘Trust region methods are powerful and effective optimization methods. The conic model method is a new type of method with more information available at each iteration than standard quadratic-based methods. The advantages of the above two methods can be combined to form a more powerful method for constrained optimization. The trust region subproblem of our method is to minimize a conic function subject to the linearized constraints and trust region bound. At the same time, the new algorithm still possesses robust global properties. The global convergence of the new algorithm under standard conditions is established.
