In this paper, a new Modified Bacterial Foraging Algorithm (MBFA) method is developed to incorporate FACTS devices in optimal power flow (OPF) problem. This method can provide an enhanced economic solution with the us...In this paper, a new Modified Bacterial Foraging Algorithm (MBFA) method is developed to incorporate FACTS devices in optimal power flow (OPF) problem. This method can provide an enhanced economic solution with the use of controllable FACTS devices. Two types of FACTS devices, thyristor controlled series compensators (TCSC) and Static VAR Compensator (SVC) are considered in this method. The basic bacterial foraging algorithm (BFA) is an evolutionary optimization technique inspired by the foraging behavior of the E. coli bacteria. The strategy of the OPF problem is decomposed in two sub-problems, the first sub-problem related to active power planning to minimize the fuel cost function, and the second sub-problem designed to make corrections to the voltage deviation and reactive power violation based in an efficient reactive power planning of multi Static VAR Compensator (SVC). The specified power flow control constraints due to the use of FACTS devices are included in the OPF problem. The proposed method decomposes the solution of such modified OPF problem into two sub problems’ iteration. The first sub problem is a power flow control problem and the second sub problem is a modified Bacterial foraging algorithm (MBFA) OPF problem. The two sub problems are solved iteratively until convergence. Case studies are presented to show the effectiveness of the proposed method.展开更多
As an emerging trend in power grid development,the AC/DC hybrid power grid presents the characteristics of multi-type DC links and large-scale AC/DC interconnection.However,existing research on AC/DC power flow calcul...As an emerging trend in power grid development,the AC/DC hybrid power grid presents the characteristics of multi-type DC links and large-scale AC/DC interconnection.However,existing research on AC/DC power flow calculation is mainly based on single-object models,ignoring the complex interactions and interdependencies between the AC system and various types of DC links in the hybrid power grid,such as LCCHVDC,MMC-HVDC,and LCC-MMC hybrid HVDC.Therefore,this paper proposes a power flow calculation algorithm for large-scale AC/DC systems with multi-type DC links.Firstly,a CIM/XML document conversion strategy applicable to the AC/DC system is proposed.Then,a unified modeling method is used to derive the power flow model of the AC/DC system,and a unified iterative algorithm for the large-scale AC/DC system with multi-type DC links is proposed.Finally,the algorithm’s correctness and effectiveness are verified by comparing it with actual measurements from the Southern Power Grid of China,with a voltage deviation of less than 1%.The research shows that the proposed algorithm has good convergence and high computational efficiency,which is applicable to power flow calculations in large-scale DC-embedded hybrid AC/DC grids in the future.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
High proportion of renewable energies and the installation of power electronic devices(PEDs)pose tough challenges to the operation of power systems.In this paper,the remote coordination adjustment(RCA)of PEDs in stoch...High proportion of renewable energies and the installation of power electronic devices(PEDs)pose tough challenges to the operation of power systems.In this paper,the remote coordination adjustment(RCA)of PEDs in stochastic scenarios is studied.The steady-state model for the AC/DC system with PEDs is first established,and the alternate iteration method based on linearization(AIML)is adopted,especially for efficient deterministic power flow calculation.Then,the RCA is proposed using a modular local sensitivity method combined with AIML,which can adjust the electrical variables by diverse PEDs with high efficiency.Additionally,the probabilistic power flow calculation using the quasi-Monte Carlo method with the adaptive sampling number(ASN-QMC)is introduced to keep the balance between the computational efficiency and accuracy,as well as demonstrating the positive impact of RCA by the PEDs in stochastic scenarios.The effectiveness of the proposed RCA is validated by a series of modified IEEE test systems.展开更多
This paper employs an efficacious analytical tool,adaptive simplified human learning optimization(ASHLO)algorithm,to solve optimal power flow(OPF)problem in AC/DC hybrid power system,considering valve-point loading ef...This paper employs an efficacious analytical tool,adaptive simplified human learning optimization(ASHLO)algorithm,to solve optimal power flow(OPF)problem in AC/DC hybrid power system,considering valve-point loading effects of generators,carbon tax,and prohibited operating zones of generators,respectively.ASHLO algorithm,involves random learning operator,individual learning operator,social learning operator and adaptive strategies.To compare and analyze the computation performance of the ASHLO method,the proposed ASHLO method and other heuristic intelligent optimization methods are employed to solve OPF problem on the modified IEEE 30-bus and 118-bus AC/DC hybrid test system.Numerical results indicate that the ASHLO method has good convergent property and robustness.Meanwhile,the impacts of wind speeds and locations of HVDC transmission line integrated into the AC network on the OPF results are systematically analyzed.展开更多
进化类算法和内点法交替迭代的混合算法在求解含电压源换流器的高压直流输电(voltage source converter basedhigh voltage direct current,VSC-HVDC)的交直流系统最优潮流(optimal power flow,OPF)问题时由于截断误差的影响和VSC-HVDC...进化类算法和内点法交替迭代的混合算法在求解含电压源换流器的高压直流输电(voltage source converter basedhigh voltage direct current,VSC-HVDC)的交直流系统最优潮流(optimal power flow,OPF)问题时由于截断误差的影响和VSC-HVDC控制方式的限制,容易发生振荡,因此提出一种基于差分进化(differential evolution,DE)和原—对偶内点法(primal-dual interior point method,PDIPM)的统一混合迭代算法。算法的主要思想是以DE算法为框架,对离散变量进行优化,在DE算法的每一次迭代过程中,采用PDIPM对每个DE个体进行连续变量的优化和适应度评估。由于采用PDIPM进行DE种群适应度评估,无需设定VSC-HVDC的控制方式,因此提高了算法的全局寻优能力。多个算例结果表明,该混合算法数值稳定性高,寻优能力强,能很好地解决含两端、多端、多馈入VSC-HVDC的交直流系统最优潮流问题。展开更多
提出一种基于带精英策略的快速非支配排序遗传算法(non-dominated sorting genetic algorithm-II,NSGA-II)和逼近理想解排序(technique for order preference by similarity to ideal solution,TOPSIS)的含VSC-HVDC交直流系统多目标最...提出一种基于带精英策略的快速非支配排序遗传算法(non-dominated sorting genetic algorithm-II,NSGA-II)和逼近理想解排序(technique for order preference by similarity to ideal solution,TOPSIS)的含VSC-HVDC交直流系统多目标最优潮流算法,统一协调系统运行的经济性及环保要求等目标。首先,基于含VSC-HVDC交直流系统的稳态模型,建立了综合考虑网络损耗和环境因素的多目标最优潮流模型;然后,采用混合编码方式,通过NSGA-II得到帕累托最优解集;最后,采用TOPSIS法评估各决策方案的相对优劣,以帮助运行人员选取有效的折中解。基于IEEE 14节点系统和IEEE 118节点系统的算例结果验证了所提方法的有效性。展开更多
多端柔性直流输电系统(voltage source converter based multi-terminal direct current system,VSC-MTDC)是在两端直流输电基础上发展而来的直流输电系统,可靠性高、适用于海上风电并网等场景,相应的控制策略更加多样,其潮流模型也更...多端柔性直流输电系统(voltage source converter based multi-terminal direct current system,VSC-MTDC)是在两端直流输电基础上发展而来的直流输电系统,可靠性高、适用于海上风电并网等场景,相应的控制策略更加多样,其潮流模型也更加复杂。该文分析VSC换流站和MTDC的稳态模型,研究可适用于VSC-MTDC的不同拓扑和连接方式的潮流模型;研究多端直流各种控制策略潮流计算模型的不同点并推导出其方程。在此基础上,提出一种兼具统一迭代法和交替迭代法优点的含VSC-MTDC交直流系统潮流算法,给出初值和边界条件求解方法,对于不同直流拓扑和交流系统都能够进行求解。最后通过2个实际算例验证该文潮流模型的有效性和收敛性,对于不同控制方式、不同运行场景和直流拓扑都能够迅速、稳定收敛。展开更多
电压源换流器(voltage source converter,VSC)在稳态模型和工作原理上与传统高压直流输电(high voltage directcurrent,HVDC)的换流器有本质区别,因此传统的交直流系统最优潮流计算方法不适用于含基于电压源换流器高压直流输电(VSC base...电压源换流器(voltage source converter,VSC)在稳态模型和工作原理上与传统高压直流输电(high voltage directcurrent,HVDC)的换流器有本质区别,因此传统的交直流系统最优潮流计算方法不适用于含基于电压源换流器高压直流输电(VSC based HVDC,VSC-HVDC)的交直流系统。讨论一种适用于原对偶内点法(primal-dual interior-pointmethod,PDIPM)和预测校正内点法(predictor-corrector PDIPM,PCPDIPM)解最优潮流的VSC-HVDC稳态模型。基于该稳态模型,将VSC-HVDC直流网络与交流系统结合起来,对交直流系统进行联立求解,并对多组算例进行仿真和分析,算例结果表明原对偶内点法在解决含VSC-HVDC的最优潮流问题的能力上,保持了传统内点法最优潮流的高效性,而在同样的条件下,预测–校正内点法迭代次数大大少于原对偶内点法。展开更多
已有的多目标潮流优化模型和算法对含电压源换流器的高压直流输电(Voltage Source Converter Based High Voltage Direct Current,VSC-HVDC)不再适用。针对VSC-HVDC的特点,提出了以有功网损最小、电压水平最好(即电压的偏移量最小)、系...已有的多目标潮流优化模型和算法对含电压源换流器的高压直流输电(Voltage Source Converter Based High Voltage Direct Current,VSC-HVDC)不再适用。针对VSC-HVDC的特点,提出了以有功网损最小、电压水平最好(即电压的偏移量最小)、系统的静态电压稳定裕度最大及供电能力最大同时作为优化目标,从而构建了含VSC-HVDC的交直流系统多目标最优潮流模型;针对此模型连续变量和离散变量共存的特点,提出了内点法和NSGA2算法相结合的交替求解算法,可获得多个Pareto最优解,并具有较高的计算效率。最后通过仿真算例验证了所提方法的有效性和高效性。展开更多
文摘In this paper, a new Modified Bacterial Foraging Algorithm (MBFA) method is developed to incorporate FACTS devices in optimal power flow (OPF) problem. This method can provide an enhanced economic solution with the use of controllable FACTS devices. Two types of FACTS devices, thyristor controlled series compensators (TCSC) and Static VAR Compensator (SVC) are considered in this method. The basic bacterial foraging algorithm (BFA) is an evolutionary optimization technique inspired by the foraging behavior of the E. coli bacteria. The strategy of the OPF problem is decomposed in two sub-problems, the first sub-problem related to active power planning to minimize the fuel cost function, and the second sub-problem designed to make corrections to the voltage deviation and reactive power violation based in an efficient reactive power planning of multi Static VAR Compensator (SVC). The specified power flow control constraints due to the use of FACTS devices are included in the OPF problem. The proposed method decomposes the solution of such modified OPF problem into two sub problems’ iteration. The first sub problem is a power flow control problem and the second sub problem is a modified Bacterial foraging algorithm (MBFA) OPF problem. The two sub problems are solved iteratively until convergence. Case studies are presented to show the effectiveness of the proposed method.
基金supported by the Science and Technology Project of China Southern Power Grid(ZDKJXM20200052).
文摘As an emerging trend in power grid development,the AC/DC hybrid power grid presents the characteristics of multi-type DC links and large-scale AC/DC interconnection.However,existing research on AC/DC power flow calculation is mainly based on single-object models,ignoring the complex interactions and interdependencies between the AC system and various types of DC links in the hybrid power grid,such as LCCHVDC,MMC-HVDC,and LCC-MMC hybrid HVDC.Therefore,this paper proposes a power flow calculation algorithm for large-scale AC/DC systems with multi-type DC links.Firstly,a CIM/XML document conversion strategy applicable to the AC/DC system is proposed.Then,a unified modeling method is used to derive the power flow model of the AC/DC system,and a unified iterative algorithm for the large-scale AC/DC system with multi-type DC links is proposed.Finally,the algorithm’s correctness and effectiveness are verified by comparing it with actual measurements from the Southern Power Grid of China,with a voltage deviation of less than 1%.The research shows that the proposed algorithm has good convergence and high computational efficiency,which is applicable to power flow calculations in large-scale DC-embedded hybrid AC/DC grids in the future.
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。
基金supported by the National Natural Science Foundation of China(No.52177071).
文摘High proportion of renewable energies and the installation of power electronic devices(PEDs)pose tough challenges to the operation of power systems.In this paper,the remote coordination adjustment(RCA)of PEDs in stochastic scenarios is studied.The steady-state model for the AC/DC system with PEDs is first established,and the alternate iteration method based on linearization(AIML)is adopted,especially for efficient deterministic power flow calculation.Then,the RCA is proposed using a modular local sensitivity method combined with AIML,which can adjust the electrical variables by diverse PEDs with high efficiency.Additionally,the probabilistic power flow calculation using the quasi-Monte Carlo method with the adaptive sampling number(ASN-QMC)is introduced to keep the balance between the computational efficiency and accuracy,as well as demonstrating the positive impact of RCA by the PEDs in stochastic scenarios.The effectiveness of the proposed RCA is validated by a series of modified IEEE test systems.
基金supported by National Natural Science Foundation of China(No.51377103)the technology project of State Grid Corporation of China:Research on Multi-Level Decomposition Coordination of the Pareto Set of Multi-Objective Optimization Problem in Bulk Power System(No.SGSXDKYDWKJ2015-001)the support from State Energy Smart Grid R&D Center(SHANGHAI)
文摘This paper employs an efficacious analytical tool,adaptive simplified human learning optimization(ASHLO)algorithm,to solve optimal power flow(OPF)problem in AC/DC hybrid power system,considering valve-point loading effects of generators,carbon tax,and prohibited operating zones of generators,respectively.ASHLO algorithm,involves random learning operator,individual learning operator,social learning operator and adaptive strategies.To compare and analyze the computation performance of the ASHLO method,the proposed ASHLO method and other heuristic intelligent optimization methods are employed to solve OPF problem on the modified IEEE 30-bus and 118-bus AC/DC hybrid test system.Numerical results indicate that the ASHLO method has good convergent property and robustness.Meanwhile,the impacts of wind speeds and locations of HVDC transmission line integrated into the AC network on the OPF results are systematically analyzed.
文摘进化类算法和内点法交替迭代的混合算法在求解含电压源换流器的高压直流输电(voltage source converter basedhigh voltage direct current,VSC-HVDC)的交直流系统最优潮流(optimal power flow,OPF)问题时由于截断误差的影响和VSC-HVDC控制方式的限制,容易发生振荡,因此提出一种基于差分进化(differential evolution,DE)和原—对偶内点法(primal-dual interior point method,PDIPM)的统一混合迭代算法。算法的主要思想是以DE算法为框架,对离散变量进行优化,在DE算法的每一次迭代过程中,采用PDIPM对每个DE个体进行连续变量的优化和适应度评估。由于采用PDIPM进行DE种群适应度评估,无需设定VSC-HVDC的控制方式,因此提高了算法的全局寻优能力。多个算例结果表明,该混合算法数值稳定性高,寻优能力强,能很好地解决含两端、多端、多馈入VSC-HVDC的交直流系统最优潮流问题。
文摘提出一种基于带精英策略的快速非支配排序遗传算法(non-dominated sorting genetic algorithm-II,NSGA-II)和逼近理想解排序(technique for order preference by similarity to ideal solution,TOPSIS)的含VSC-HVDC交直流系统多目标最优潮流算法,统一协调系统运行的经济性及环保要求等目标。首先,基于含VSC-HVDC交直流系统的稳态模型,建立了综合考虑网络损耗和环境因素的多目标最优潮流模型;然后,采用混合编码方式,通过NSGA-II得到帕累托最优解集;最后,采用TOPSIS法评估各决策方案的相对优劣,以帮助运行人员选取有效的折中解。基于IEEE 14节点系统和IEEE 118节点系统的算例结果验证了所提方法的有效性。
文摘多端柔性直流输电系统(voltage source converter based multi-terminal direct current system,VSC-MTDC)是在两端直流输电基础上发展而来的直流输电系统,可靠性高、适用于海上风电并网等场景,相应的控制策略更加多样,其潮流模型也更加复杂。该文分析VSC换流站和MTDC的稳态模型,研究可适用于VSC-MTDC的不同拓扑和连接方式的潮流模型;研究多端直流各种控制策略潮流计算模型的不同点并推导出其方程。在此基础上,提出一种兼具统一迭代法和交替迭代法优点的含VSC-MTDC交直流系统潮流算法,给出初值和边界条件求解方法,对于不同直流拓扑和交流系统都能够进行求解。最后通过2个实际算例验证该文潮流模型的有效性和收敛性,对于不同控制方式、不同运行场景和直流拓扑都能够迅速、稳定收敛。
文摘电压源换流器(voltage source converter,VSC)在稳态模型和工作原理上与传统高压直流输电(high voltage directcurrent,HVDC)的换流器有本质区别,因此传统的交直流系统最优潮流计算方法不适用于含基于电压源换流器高压直流输电(VSC based HVDC,VSC-HVDC)的交直流系统。讨论一种适用于原对偶内点法(primal-dual interior-pointmethod,PDIPM)和预测校正内点法(predictor-corrector PDIPM,PCPDIPM)解最优潮流的VSC-HVDC稳态模型。基于该稳态模型,将VSC-HVDC直流网络与交流系统结合起来,对交直流系统进行联立求解,并对多组算例进行仿真和分析,算例结果表明原对偶内点法在解决含VSC-HVDC的最优潮流问题的能力上,保持了传统内点法最优潮流的高效性,而在同样的条件下,预测–校正内点法迭代次数大大少于原对偶内点法。
文摘已有的多目标潮流优化模型和算法对含电压源换流器的高压直流输电(Voltage Source Converter Based High Voltage Direct Current,VSC-HVDC)不再适用。针对VSC-HVDC的特点,提出了以有功网损最小、电压水平最好(即电压的偏移量最小)、系统的静态电压稳定裕度最大及供电能力最大同时作为优化目标,从而构建了含VSC-HVDC的交直流系统多目标最优潮流模型;针对此模型连续变量和离散变量共存的特点,提出了内点法和NSGA2算法相结合的交替求解算法,可获得多个Pareto最优解,并具有较高的计算效率。最后通过仿真算例验证了所提方法的有效性和高效性。
