In a multiple voltage source converter(VSC)system,the nonlinear characteristics of phase-locked loops(PLLs)and their interactions have a significant influence on the synchronization stability of converters.In this pap...In a multiple voltage source converter(VSC)system,the nonlinear characteristics of phase-locked loops(PLLs)and their interactions have a significant influence on the synchronization stability of converters.In this paper,these influences are investigated from the perspective of the time domain.First,a novel time-domain model of the multi-VSC system is obtained by using a multi-scale method.On this basis,a stability criterion is proposed to assess the synchronization stability of the system.Then,the accuracy of the time-domain model and its stability criterion in various conditions are discussed.Moreover,the negative impact of the interaction on the system is quantified.Finally,the above theoretical analysis is also verified in the controller hardware-in-the-loop(CHIL)experiments.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
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
基金supported by the Science and Technology Project of State Grid Corporation of China(5400-202199281A-0-0-00).
文摘In a multiple voltage source converter(VSC)system,the nonlinear characteristics of phase-locked loops(PLLs)and their interactions have a significant influence on the synchronization stability of converters.In this paper,these influences are investigated from the perspective of the time domain.First,a novel time-domain model of the multi-VSC system is obtained by using a multi-scale method.On this basis,a stability criterion is proposed to assess the synchronization stability of the system.Then,the accuracy of the time-domain model and its stability criterion in various conditions are discussed.Moreover,the negative impact of the interaction on the system is quantified.Finally,the above theoretical analysis is also verified in the controller hardware-in-the-loop(CHIL)experiments.
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。
