Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits o...Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits of multi terminal DC (MTDC) tie lines as compared to the traditional HVAC forms the main objective of this paper. Probabilistic load flow (PLF) is applied to determine the system parameters while the uncertainties are modelled using Scenario Based Method (SBM). The simulation results reveal that with the use of MTDC tie lines, the frequency and voltage stability in the MAMODED with renewable energy sources (RES) are enhanced while keeping the MTDC power exchange interface nodes at secure levels.展开更多
Gas injection process is a very important technology in enhanced oil recovery.Minimum miscible pressure is one of the key parameters in gas injection processes.Various experimental methods such as slim tube are used t...Gas injection process is a very important technology in enhanced oil recovery.Minimum miscible pressure is one of the key parameters in gas injection processes.Various experimental methods such as slim tube are used to measure MMP.These methods are costly and time consuming.Recently computational methods are used in order to achieve a cost-effective and reliable technique to evaluate MMP.In this work,a new methodology has been proposed for determination of MMP using the minimum tie line length method.A real mixing cell model was developed to estimate the MMP,MME and key tie lines.This method is simple,robust,and faster than conventional one-dimensional simulation of slim tube.The new mixing cells method can accurately determine the whole key tie lines to a shift,regardless of the number of injection gas and reservoir fluid components.Unlike other methods of mixing cells,this method automatically corrects dispersion by additional contacts to achieve the low variation domain of tie line slope.Also,the determination and implementation of the minimum miscibility enrichment are investigated.展开更多
在混合双馈入直流输电系统中,由于电网换相换流器型高压直流输电(line commutated converter based high voltage direct current,LCC-HVDC)的存在,系统在不同的联络线长度下呈现出不同的高频振荡特征。为研究混合双馈入直流输电系统的...在混合双馈入直流输电系统中,由于电网换相换流器型高压直流输电(line commutated converter based high voltage direct current,LCC-HVDC)的存在,系统在不同的联络线长度下呈现出不同的高频振荡特征。为研究混合双馈入直流输电系统的高频振荡特征及机理,首先建立系统的状态空间模型,基于此研究系统的高频振荡特征,结果表明,由于LCC子系统的存在,在不同的联络线长度下混合双馈入直流输电系统呈现出不同的高频振荡特征。然后,建立混合双馈入直流系统的高频阻抗模型,研究LCC子系统、联络线长度、模块化多电平换流器(modular multilevel converter,MMC)控制链路延时、交流线路长度等对系统高频阻抗的影响。结果表明,对于无电气距离的混合双馈入系统,LCC滤波器的存在使其无高频振荡风险;对于有电气距离的混合双馈入系统,当LCC和MMC子系统之间的电气距离较近时,LCC交流滤波器对系统高频振荡的抑制效果随着联络线长度的增大而减弱。最后,提出混合双馈入系统无高频振荡风险的联络线临界长度确定方法,并通过理论分析和电磁暂态仿真进行有效性验证。展开更多
针对高比例非同步电源接入下电网等效惯量水平感知难题,提出一种基于量测数据的电网等效惯量在线估计方法。首先,利用发电机有功功率变化及节点频率数据,采用带外部输入的自回归滑动平均(auto regression and moving average model with...针对高比例非同步电源接入下电网等效惯量水平感知难题,提出一种基于量测数据的电网等效惯量在线估计方法。首先,利用发电机有功功率变化及节点频率数据,采用带外部输入的自回归滑动平均(auto regression and moving average model with exogenous input,ARMAX)模型对各区域/整个电网有功-频率动态变化进行建模。进而,基于增广递推最小二乘(recursive extended least squares,RELS)算法实现自回归滑动平均模型中未知参数的求解,辨识得到系统或区域惯性常数的估算值。此外,考虑区域间交流联络线提供的惯量支撑,对出现不平衡功率扰动后的区域惯量通过联络线耦合现象进行估计和分析。最后,基于某省级电网实际数据进行仿真测试,验证了所提方法的正确性和有效性,并对互联区域联络线提供的惯量支撑进行了分析。展开更多
借助联络线可用传输容量(available transfer capability,ATC)来评估跨区电网的通道传输能力,可能导致据此得到的联络线计划与子区域的运行条件不匹配或引起额外的再调度成本。提出了一种基于广域和邻域时段组合的联络线功率可行域分析...借助联络线可用传输容量(available transfer capability,ATC)来评估跨区电网的通道传输能力,可能导致据此得到的联络线计划与子区域的运行条件不匹配或引起额外的再调度成本。提出了一种基于广域和邻域时段组合的联络线功率可行域分析方法,可以更好地适应日前调度的场景需求。首先,借助多面体投影理论分析了时段耦合关系对可行域计算的影响,并提出应对思路。然后,针对日前调度跨时段耦合的特点,设计了广域和邻域时段组合的策略并构造可行域模型,兼顾时段跨度较大的耦合约束以及相邻时段的耦合约束的影响,将广域和邻域时段可行域的计算结果合成得到日前调度各时段的联络线功率可行域。最后,基于118节点系统比对了不同方法计算可行域结果的差异,并分析了广域、邻域组合策略的互补作用;以与118节点系统互联的39节点系统为例,分析了联络线功率可行域对子区域调度计划的影响,由此验证了所提方法的有效性。展开更多
文摘Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits of multi terminal DC (MTDC) tie lines as compared to the traditional HVAC forms the main objective of this paper. Probabilistic load flow (PLF) is applied to determine the system parameters while the uncertainties are modelled using Scenario Based Method (SBM). The simulation results reveal that with the use of MTDC tie lines, the frequency and voltage stability in the MAMODED with renewable energy sources (RES) are enhanced while keeping the MTDC power exchange interface nodes at secure levels.
文摘Gas injection process is a very important technology in enhanced oil recovery.Minimum miscible pressure is one of the key parameters in gas injection processes.Various experimental methods such as slim tube are used to measure MMP.These methods are costly and time consuming.Recently computational methods are used in order to achieve a cost-effective and reliable technique to evaluate MMP.In this work,a new methodology has been proposed for determination of MMP using the minimum tie line length method.A real mixing cell model was developed to estimate the MMP,MME and key tie lines.This method is simple,robust,and faster than conventional one-dimensional simulation of slim tube.The new mixing cells method can accurately determine the whole key tie lines to a shift,regardless of the number of injection gas and reservoir fluid components.Unlike other methods of mixing cells,this method automatically corrects dispersion by additional contacts to achieve the low variation domain of tie line slope.Also,the determination and implementation of the minimum miscibility enrichment are investigated.
文摘在混合双馈入直流输电系统中,由于电网换相换流器型高压直流输电(line commutated converter based high voltage direct current,LCC-HVDC)的存在,系统在不同的联络线长度下呈现出不同的高频振荡特征。为研究混合双馈入直流输电系统的高频振荡特征及机理,首先建立系统的状态空间模型,基于此研究系统的高频振荡特征,结果表明,由于LCC子系统的存在,在不同的联络线长度下混合双馈入直流输电系统呈现出不同的高频振荡特征。然后,建立混合双馈入直流系统的高频阻抗模型,研究LCC子系统、联络线长度、模块化多电平换流器(modular multilevel converter,MMC)控制链路延时、交流线路长度等对系统高频阻抗的影响。结果表明,对于无电气距离的混合双馈入系统,LCC滤波器的存在使其无高频振荡风险;对于有电气距离的混合双馈入系统,当LCC和MMC子系统之间的电气距离较近时,LCC交流滤波器对系统高频振荡的抑制效果随着联络线长度的增大而减弱。最后,提出混合双馈入系统无高频振荡风险的联络线临界长度确定方法,并通过理论分析和电磁暂态仿真进行有效性验证。
文摘针对高比例非同步电源接入下电网等效惯量水平感知难题,提出一种基于量测数据的电网等效惯量在线估计方法。首先,利用发电机有功功率变化及节点频率数据,采用带外部输入的自回归滑动平均(auto regression and moving average model with exogenous input,ARMAX)模型对各区域/整个电网有功-频率动态变化进行建模。进而,基于增广递推最小二乘(recursive extended least squares,RELS)算法实现自回归滑动平均模型中未知参数的求解,辨识得到系统或区域惯性常数的估算值。此外,考虑区域间交流联络线提供的惯量支撑,对出现不平衡功率扰动后的区域惯量通过联络线耦合现象进行估计和分析。最后,基于某省级电网实际数据进行仿真测试,验证了所提方法的正确性和有效性,并对互联区域联络线提供的惯量支撑进行了分析。
文摘借助联络线可用传输容量(available transfer capability,ATC)来评估跨区电网的通道传输能力,可能导致据此得到的联络线计划与子区域的运行条件不匹配或引起额外的再调度成本。提出了一种基于广域和邻域时段组合的联络线功率可行域分析方法,可以更好地适应日前调度的场景需求。首先,借助多面体投影理论分析了时段耦合关系对可行域计算的影响,并提出应对思路。然后,针对日前调度跨时段耦合的特点,设计了广域和邻域时段组合的策略并构造可行域模型,兼顾时段跨度较大的耦合约束以及相邻时段的耦合约束的影响,将广域和邻域时段可行域的计算结果合成得到日前调度各时段的联络线功率可行域。最后,基于118节点系统比对了不同方法计算可行域结果的差异,并分析了广域、邻域组合策略的互补作用;以与118节点系统互联的39节点系统为例,分析了联络线功率可行域对子区域调度计划的影响,由此验证了所提方法的有效性。
