Digital substations are mostly important in the future of the electric power industry which makes their testing a critical process to ensure the required reliability and security of the grid.The paper introduces the d...Digital substations are mostly important in the future of the electric power industry which makes their testing a critical process to ensure the required reliability and security of the grid.The paper introduces the definition of a digital substation and efficient testing,as well as the requirements for isolation during testing.It later describes testing related features in IEC 61850 Edition 2 and testing methods that can be used in digital substations.Maintenance testing examples and testing tools requirements are also presented.And remote testing principles are described at the end of the paper.The proposed remote testing by controlling the test system in a remote substation from the convenience of the engineering office brings significant benefits by improving efficiency and safety,as well as reducing outage times.展开更多
This paper presents an integrated protection technique for power distribution systems. A novel integrated protection scheme based on overcurrent protection technique for distribution system is described, in which a sp...This paper presents an integrated protection technique for power distribution systems. A novel integrated protection scheme based on overcurrent protection technique for distribution system is described, in which a specially designed protection relay is installed at each substation of a network and responsible for the protection of every line sections connected to the substation busbar The conventional directional overcurrent and the new adaptive accelerated protection algorithms with multiple settings are implemented into the relay to cover all the protected line sections. The paper includes studies of a typical multi section distribution network to demonstrate the principle of the scheme. Studies show that the new scheme not only offer the new protection features for individual power line section, but also provide the characteristics of integrated protection.展开更多
The paper has presented the impact on the line protection performance with the introduction of MUs （merging units） in the process bus level. The paper begins with the introduction on modem digital substation structu...The paper has presented the impact on the line protection performance with the introduction of MUs （merging units） in the process bus level. The paper begins with the introduction on modem digital substation structure and process bus. Then, the paper describes the performances of different sensors such as CTs （current transformers）, CVTs （capacitive voltage transformers）, FOCS （fiber optical current transducers） and FOVS （fiber optical voltage transducers）. With the use of above transducers together with MUs, the performance of distance protection function and line differential protection function have been investigated and presented. Finally, conclusions based on the study are presented in the paper.展开更多
The traditional“three defense lines”for power systems are based on local information and static protection&control strategy,which are not suitable to modern large-scale power systems.In order to improve the secu...The traditional“three defense lines”for power systems are based on local information and static protection&control strategy,which are not suitable to modern large-scale power systems.In order to improve the security of UHV hybrid power grids,the Integrated Wide Area Protection&Control(IWAPC)is proposed in this paper by applying the new technologies of synchronized high-speed communication,which integrates“three defense lines”and promotes existing wide area protection only for security control.The IWAPC is the hierarchical protection and control system which provides the protection and control for wide area power networks to improve their reliability and security.It is divided into three levels,the local bay level,the substation integrated protection level and the wide area protection level.The wide area real-time protection and control information platform is the most important part of the IWAPC,which is based on a synchronized wide area communication network.The key technologies and new development trends include network topology analysis,wide area backup protection,wide area intelligent reclosing,wide area load shedding,wide area auto-switching,overload cutoff and transfer,transmission section protection,intelligent system splitting and dynamic stability control.It cannot only integrate three lines of defense for power system protection and control,but also improve security of the power grid.展开更多
文摘Digital substations are mostly important in the future of the electric power industry which makes their testing a critical process to ensure the required reliability and security of the grid.The paper introduces the definition of a digital substation and efficient testing,as well as the requirements for isolation during testing.It later describes testing related features in IEC 61850 Edition 2 and testing methods that can be used in digital substations.Maintenance testing examples and testing tools requirements are also presented.And remote testing principles are described at the end of the paper.The proposed remote testing by controlling the test system in a remote substation from the convenience of the engineering office brings significant benefits by improving efficiency and safety,as well as reducing outage times.
文摘This paper presents an integrated protection technique for power distribution systems. A novel integrated protection scheme based on overcurrent protection technique for distribution system is described, in which a specially designed protection relay is installed at each substation of a network and responsible for the protection of every line sections connected to the substation busbar The conventional directional overcurrent and the new adaptive accelerated protection algorithms with multiple settings are implemented into the relay to cover all the protected line sections. The paper includes studies of a typical multi section distribution network to demonstrate the principle of the scheme. Studies show that the new scheme not only offer the new protection features for individual power line section, but also provide the characteristics of integrated protection.
文摘The paper has presented the impact on the line protection performance with the introduction of MUs （merging units） in the process bus level. The paper begins with the introduction on modem digital substation structure and process bus. Then, the paper describes the performances of different sensors such as CTs （current transformers）, CVTs （capacitive voltage transformers）, FOCS （fiber optical current transducers） and FOVS （fiber optical voltage transducers）. With the use of above transducers together with MUs, the performance of distance protection function and line differential protection function have been investigated and presented. Finally, conclusions based on the study are presented in the paper.
文摘The traditional“three defense lines”for power systems are based on local information and static protection&control strategy,which are not suitable to modern large-scale power systems.In order to improve the security of UHV hybrid power grids,the Integrated Wide Area Protection&Control(IWAPC)is proposed in this paper by applying the new technologies of synchronized high-speed communication,which integrates“three defense lines”and promotes existing wide area protection only for security control.The IWAPC is the hierarchical protection and control system which provides the protection and control for wide area power networks to improve their reliability and security.It is divided into three levels,the local bay level,the substation integrated protection level and the wide area protection level.The wide area real-time protection and control information platform is the most important part of the IWAPC,which is based on a synchronized wide area communication network.The key technologies and new development trends include network topology analysis,wide area backup protection,wide area intelligent reclosing,wide area load shedding,wide area auto-switching,overload cutoff and transfer,transmission section protection,intelligent system splitting and dynamic stability control.It cannot only integrate three lines of defense for power system protection and control,but also improve security of the power grid.
