The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Modeling study provides a more effective and flexible way for research of high impedance fault (HIF) detection. An accurate model which can reveal most features of HIF is very important. In this paper, based on extensive investigation into documented test results, a set of most common and agreeable features of HIF has been summarized: the arc features, the non-linearity, the time-varied resistance...
The re-closing time of a transmission line has a distinct influence on power system transient stability. There is an optimal re-closing time (ORT) for all transmission line faults, no matter the instantaneous fault or permanent one. Based on the transient energy function (TEF) theory with classical models considered, the ORT can be calculated accurately. This paper mainly focuses attention on the...
The precision of impedance fault location algorithm is deteriorated by the extremely large shunt capacitance in UHV line. And the traditional improved ways are all invalid caused by the nonlinearity of measurement impedance in relay and the frequent variations of operation modes in UHV system. In response to this question, a novel impedance fault location algorithm is proposed for phase faults. It...
The study of various stability-control methods for a transmission system indicates that the reclosing time of a transmission line has a distinct influence on system stability. And there is an optimal reclosing time (ORT) for all transmission line faults. Utilizing the transient energy function (TEF) with classical models considered, the ORT setting computation method is proposed. This paper shows...
This paper presents the extended study on current differential protection schemes based on symmetrical components. The principles of the protection schemes are analyzed firstly. Their performances are evaluated on a typical 500 kV power transmission line system model using EMTP. Extensive simulation studies are presented under various system and fault conditions, such as variations in system load...
This paper presents the extended study on the application of new directional comparison technique for the protection of teed circuits. The technique relies on the detection of fault generated transient current signals. Comparison between the polarities of the captured current transient signals from the CT outputs at each end of the protected teed circuit will determine whether or not a fault is inside...
This paper presents a new directional comparison protection scheme specially designed for distribution systems. A number of well-proved directional techniques were chosen for this study. To evaluate their performances, a typical distribution line system was modeled using EMTP, which is able to offer many variations to cover all possible fault conditions such as with different fault types, fault locations,...
This paper presents a new integrated protection scheme based on distance protection technique. An integrated protection relay is installed at a substation and interfaced to every line through the CTs and busbar VT. The relay is also interfaced to the substation communication network which is communicated with all neighboring substations. The directional detection, phase selection and adaptive distance...
This paper reports on the development of integrated protection for power system. The concept of integrated protection is introduced, in which a centralized protection system (or relay) provides the protection of multiple power plant or a substation. Examples are given of the protection schemes with the features of integrated protection which are currently under development. A novel integrated protection...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.