大规模风电、光伏新能源经交流送出系统中,送出线路发生故障后,新能源电源控制的故障响应严重影响交流线路距离保护的动作性能。该文分析了新能源电源典型控制策略对故障后电源等值阻抗及系统功角的影响,故障后电源等值阻抗和系统功角...大规模风电、光伏新能源经交流送出系统中,送出线路发生故障后,新能源电源控制的故障响应严重影响交流线路距离保护的动作性能。该文分析了新能源电源典型控制策略对故障后电源等值阻抗及系统功角的影响,故障后电源等值阻抗和系统功角显著增大。进一步研究了不同类型距离保护的动作性能。针对测距式距离保护,揭示了线路正向区外或反向区外发生经过渡电阻故障时保护误动、线路正向区内故障时保护拒动机理。针对比相式距离保护,揭示了正序极化电压相位受控偏移导致线路区内相间短路故障时保护拒动、区外反向故障时保护误动机理。利用实时数字仿真平台(real time digital simulation system,RTDS)建立了仿真模型,利用仿真结果和现场实际误动数据验证了理论分析的正确性,为大规模新能源送出线路故障分析和后备保护配置提供了理论依据。展开更多
To guarantee a reliable power supply,the expected operation of all the components in the power system is critical.Distance protection system is primarily responsible of isolating the faulty section from the healthy pa...To guarantee a reliable power supply,the expected operation of all the components in the power system is critical.Distance protection system is primarily responsible of isolating the faulty section from the healthy part for the grid.Failure in protection devices can result in multiple conflicting alarms at the power grid operation center and complex event analysis to manually find the root cause of the observed system state.If not handled in time,it may lead to the propagation of the faults/failures to the adjacent transmission lines and components.With availability of the synchronized measurements from phasor measurement units(PMUs),real-time system monitoring and automated failure diagnosis are feasible.With multiple adverse events and possible data anomalies,the complexity of the problem will be escalated.In this paper,a PMUbased algorithm is presented and discussed to detect the root cause of the failure in transmission protection system based on the observed state,e.g.multiple line tripping andbreaker failures.The failure diagnosis algorithm is further enhanced to come up with the fully functional version of the failure diagnosis tool,which is tailored for the cases in which the PMU anomalies are present.In the developed algorithm,the validity of the PMU data is critical.However,such causes as communication errors or cyber-attacks might lead to the PMU data anomalies.This issue is welladdressed in this paper and some major types of anomaly detection methods suitable for PMU data are discussed.Results show that the ensemble approach has some distinct advantages in data anomaly detection compared to the previously used standalone algorithms.Additionally,the enhanced failure diagnosis method is developed to clean the inaccurate data in case of the anomaly in measured voltage magnitudes.Finally,both original and enhanced versions of the tool are tested on 96-bus test system using the real-time OPAL-RT simulator.The results show the accuracy of the enhanced tool and its advantages over the primary version of the 展开更多
文摘大规模风电、光伏新能源经交流送出系统中,送出线路发生故障后,新能源电源控制的故障响应严重影响交流线路距离保护的动作性能。该文分析了新能源电源典型控制策略对故障后电源等值阻抗及系统功角的影响,故障后电源等值阻抗和系统功角显著增大。进一步研究了不同类型距离保护的动作性能。针对测距式距离保护,揭示了线路正向区外或反向区外发生经过渡电阻故障时保护误动、线路正向区内故障时保护拒动机理。针对比相式距离保护,揭示了正序极化电压相位受控偏移导致线路区内相间短路故障时保护拒动、区外反向故障时保护误动机理。利用实时数字仿真平台(real time digital simulation system,RTDS)建立了仿真模型,利用仿真结果和现场实际误动数据验证了理论分析的正确性,为大规模新能源送出线路故障分析和后备保护配置提供了理论依据。
基金the National Science Foundation(NSF)for supporting this research projectthe help of OPAL-RT support team.
文摘To guarantee a reliable power supply,the expected operation of all the components in the power system is critical.Distance protection system is primarily responsible of isolating the faulty section from the healthy part for the grid.Failure in protection devices can result in multiple conflicting alarms at the power grid operation center and complex event analysis to manually find the root cause of the observed system state.If not handled in time,it may lead to the propagation of the faults/failures to the adjacent transmission lines and components.With availability of the synchronized measurements from phasor measurement units(PMUs),real-time system monitoring and automated failure diagnosis are feasible.With multiple adverse events and possible data anomalies,the complexity of the problem will be escalated.In this paper,a PMUbased algorithm is presented and discussed to detect the root cause of the failure in transmission protection system based on the observed state,e.g.multiple line tripping andbreaker failures.The failure diagnosis algorithm is further enhanced to come up with the fully functional version of the failure diagnosis tool,which is tailored for the cases in which the PMU anomalies are present.In the developed algorithm,the validity of the PMU data is critical.However,such causes as communication errors or cyber-attacks might lead to the PMU data anomalies.This issue is welladdressed in this paper and some major types of anomaly detection methods suitable for PMU data are discussed.Results show that the ensemble approach has some distinct advantages in data anomaly detection compared to the previously used standalone algorithms.Additionally,the enhanced failure diagnosis method is developed to clean the inaccurate data in case of the anomaly in measured voltage magnitudes.Finally,both original and enhanced versions of the tool are tested on 96-bus test system using the real-time OPAL-RT simulator.The results show the accuracy of the enhanced tool and its advantages over the primary version of the
