Electricity network is a very complex entity that comprises several components like generators, transmission lines, loads among others. As technologies continue to evolve, the complexity of the electricity network has...Electricity network is a very complex entity that comprises several components like generators, transmission lines, loads among others. As technologies continue to evolve, the complexity of the electricity network has also increased as more devices are being connected to the network. To understand the physical laws governing the operation of the network, techniques such as optimal power flow (OPF), Economic dispatch (ED) and Security constrained optimal power flow (SCOPF) were developed. These techniques have been used extensively in network operation, planning and so on. However, an in-depth presentation showcasing the merits and demerits of these techniques is still lacking in the literature. Hence, this paper intends to fill this gap. In this paper, Economic dispatch, optimal power flow and security-constrained optimal power flow are applied to a 3-bus test system using a linear programming approach. The results of the ED, OPF and SC-OPF are compared and presented.展开更多
After the digital revolution, the power system security becomes an important issue and it urges the power producers to maintain a well secured system in order to supply a quality power to the end users. This paper pre...After the digital revolution, the power system security becomes an important issue and it urges the power producers to maintain a well secured system in order to supply a quality power to the end users. This paper presents an integrated Corrective Security Constrained Optimal Power Flow (CSCOPF) with Flexible Transmission Line Impedance (FTLI) to enhance the power system security. The corrective approach of SCOPF is chosen, because it allows the corrective equipment to bring back the system to a stable operating point and hence, it offers high flexibility and better economics. The concept of FTLI arises from the ability of FACTS devices such as Thyristor Controlled Series Capacitor (TCSC), which can vary the line reactance to a certain extent. An enhanced security can be achieved by incorporating FTLI into the CSCOPF problem, since the power flow in a system is highly dependent on the line reactance. FTLI based CSCOPF can reduce the amount of rescheduling of generators, but it will result in an increased number of variables and thus, the complexity to the optimization process is increased. This highly complex problem is solved by using nonlinear programming. The AC based OPF model is preferred, since the corrective security actions require highly accurate solutions. IEEE 30 bus system is used to test the proposed scheme and the results are compared with the traditional CSCOPF. It can be seen that the proposed idea provides a notable improvement in the reduction of cost incurred for restoring the system security.展开更多
为减少温室气体的排放,以风电为代表的清洁能源大规模接入电网。如何消纳高占比、波动剧烈的风电,成为现代电力系统所面临的重要问题。在此背景下,将多端柔性直流输电系统(VSC based multi-terminal HVDC,VSCMTDC)对功率的灵活调节能力...为减少温室气体的排放,以风电为代表的清洁能源大规模接入电网。如何消纳高占比、波动剧烈的风电,成为现代电力系统所面临的重要问题。在此背景下,将多端柔性直流输电系统(VSC based multi-terminal HVDC,VSCMTDC)对功率的灵活调节能力纳入安全约束机组组合(security-constrained unit commitment,SCUC)问题中进行调控。设计日前机组组合、短期实时调节和滚动重调节三段式配合的调度框架,并基于列与约束生成算法(column-andconstraint generation,C&CG)设计三层迭代求解方法。通过该方法解决了传统二阶段鲁棒性机组组合偏于保守的弊端,有效提高了风电消纳。为了充分利用VSC换流站能独立调节有功、无功的优势,在SCUC结果的基础上进行无功电压优化,并基于Benders分解算法进行求解,有效降低了系统网损。最后,将所提模型应用于改进IEEE 30节点系统算例,验证模型的有效性和可行性。展开更多
随着电网运行对电压控制和无功管理水平要求的提高,自动电压控制(automatic voltage control,AVC)日渐成为研究的热点。由于管理模式的制约,其应用性研究在北美电网仍属空白。文中设计并实现了适用于美国东北部某互联电网特殊管理模式...随着电网运行对电压控制和无功管理水平要求的提高,自动电压控制(automatic voltage control,AVC)日渐成为研究的热点。由于管理模式的制约,其应用性研究在北美电网仍属空白。文中设计并实现了适用于美国东北部某互联电网特殊管理模式和在线运行要求的自动电压控制系统。该系统扩展了移相器元件模型的处理,并在利用最优潮流(optimal power flow,OPF)计算控制策略的过程中考虑预想故障后的静态安全约束。长时间的在线试运行数据及其评估结果表明,文中所设计和实现的自动电压控制系统应用于该电网可显著改善该电网的无功电压水平,提高电网的安全性和经济性。展开更多
安全约束机组组合(security-constrained unit commitment,SCUC)作为编制发电计划的核心环节,在电力系统优化调度等方面具有十分重要的意义。因此,该文首先从物理模型和求解方法简要概述了SCUC问题。然后,从多目标、多元化决策变量、不...安全约束机组组合(security-constrained unit commitment,SCUC)作为编制发电计划的核心环节,在电力系统优化调度等方面具有十分重要的意义。因此,该文首先从物理模型和求解方法简要概述了SCUC问题。然后,从多目标、多元化决策变量、不确定性、多时间尺度与多元约束条件5个方面梳理了物理模型驱动的SCUC的研究进展,并分析了此类方法所面临的挑战。同时,重点总结归纳了现有基于人工智能技术和数据驱动的SCUC问题的研究成果,并分析了不同类型方法的特点、优势和缺陷。最后提出了对未来基于数据驱动的SCUC研究方向的相关思考。展开更多
文摘Electricity network is a very complex entity that comprises several components like generators, transmission lines, loads among others. As technologies continue to evolve, the complexity of the electricity network has also increased as more devices are being connected to the network. To understand the physical laws governing the operation of the network, techniques such as optimal power flow (OPF), Economic dispatch (ED) and Security constrained optimal power flow (SCOPF) were developed. These techniques have been used extensively in network operation, planning and so on. However, an in-depth presentation showcasing the merits and demerits of these techniques is still lacking in the literature. Hence, this paper intends to fill this gap. In this paper, Economic dispatch, optimal power flow and security-constrained optimal power flow are applied to a 3-bus test system using a linear programming approach. The results of the ED, OPF and SC-OPF are compared and presented.
文摘After the digital revolution, the power system security becomes an important issue and it urges the power producers to maintain a well secured system in order to supply a quality power to the end users. This paper presents an integrated Corrective Security Constrained Optimal Power Flow (CSCOPF) with Flexible Transmission Line Impedance (FTLI) to enhance the power system security. The corrective approach of SCOPF is chosen, because it allows the corrective equipment to bring back the system to a stable operating point and hence, it offers high flexibility and better economics. The concept of FTLI arises from the ability of FACTS devices such as Thyristor Controlled Series Capacitor (TCSC), which can vary the line reactance to a certain extent. An enhanced security can be achieved by incorporating FTLI into the CSCOPF problem, since the power flow in a system is highly dependent on the line reactance. FTLI based CSCOPF can reduce the amount of rescheduling of generators, but it will result in an increased number of variables and thus, the complexity to the optimization process is increased. This highly complex problem is solved by using nonlinear programming. The AC based OPF model is preferred, since the corrective security actions require highly accurate solutions. IEEE 30 bus system is used to test the proposed scheme and the results are compared with the traditional CSCOPF. It can be seen that the proposed idea provides a notable improvement in the reduction of cost incurred for restoring the system security.
文摘为减少温室气体的排放,以风电为代表的清洁能源大规模接入电网。如何消纳高占比、波动剧烈的风电,成为现代电力系统所面临的重要问题。在此背景下,将多端柔性直流输电系统(VSC based multi-terminal HVDC,VSCMTDC)对功率的灵活调节能力纳入安全约束机组组合(security-constrained unit commitment,SCUC)问题中进行调控。设计日前机组组合、短期实时调节和滚动重调节三段式配合的调度框架,并基于列与约束生成算法(column-andconstraint generation,C&CG)设计三层迭代求解方法。通过该方法解决了传统二阶段鲁棒性机组组合偏于保守的弊端,有效提高了风电消纳。为了充分利用VSC换流站能独立调节有功、无功的优势,在SCUC结果的基础上进行无功电压优化,并基于Benders分解算法进行求解,有效降低了系统网损。最后,将所提模型应用于改进IEEE 30节点系统算例,验证模型的有效性和可行性。
文摘随着电网运行对电压控制和无功管理水平要求的提高,自动电压控制(automatic voltage control,AVC)日渐成为研究的热点。由于管理模式的制约,其应用性研究在北美电网仍属空白。文中设计并实现了适用于美国东北部某互联电网特殊管理模式和在线运行要求的自动电压控制系统。该系统扩展了移相器元件模型的处理,并在利用最优潮流(optimal power flow,OPF)计算控制策略的过程中考虑预想故障后的静态安全约束。长时间的在线试运行数据及其评估结果表明,文中所设计和实现的自动电压控制系统应用于该电网可显著改善该电网的无功电压水平,提高电网的安全性和经济性。
文摘安全约束机组组合(security-constrained unit commitment,SCUC)作为编制发电计划的核心环节,在电力系统优化调度等方面具有十分重要的意义。因此,该文首先从物理模型和求解方法简要概述了SCUC问题。然后,从多目标、多元化决策变量、不确定性、多时间尺度与多元约束条件5个方面梳理了物理模型驱动的SCUC的研究进展,并分析了此类方法所面临的挑战。同时,重点总结归纳了现有基于人工智能技术和数据驱动的SCUC问题的研究成果,并分析了不同类型方法的特点、优势和缺陷。最后提出了对未来基于数据驱动的SCUC研究方向的相关思考。
