Poudineh Ebrahimi, Farhad (2017) Fault-location method based on optimization for N terminal lines (N≥3) using asynchronous data of line terminals during-fault. Masters thesis, university of zabol.
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Abstract
In this thesis, new and accurate algorithms for finding faults in two-terminal, threeterminal and multi-terminal transmission lines are presented. Fault locating algorithms are converted to optimization problems and solved with Teaching Learning Based optimization (TLBO) algorithm. In location methods, the distributed parameter line model in the time domain and the non-synchronous information of the terminals collected during the fault are used. The proposed method for locating faults in two-terminal lines, in addition to high precision, unlike conventional methods, not only uses non- synchronous samples during the fault sent to the fault locator, but also does not need to the value of line parameters and the fault type detection. The performance of the proposed method has been tested with various fault incidence angles, different fault types and various conditions. These tests show the high accuracy of the proposed method. Also, the proposed method does not depend on the Thevenin impedance of two sides of the line, the fault impedance and the incidence angle of the fault. The proposed algorithm is not affected by high fault resistance and network structure. Unlike existing algorithms, the proposed fault location method for three-terminal transmission lines, not only does not require synchronous terminal information but also does not require line parameters values. In addition, the parameters of the three sections of the line are considered differently. Advantages of the proposed method are: 1) not needing to classify the type of fault and select the faulty phase, 2) not needing information about the line parameters, 3) not dependenting on the pre-fault conditions and the network structure. The locating process is a two-stage one. In the first step, faulty section is identified by using the fault section index to reduce the search space. The second step is used to determine the exact fault distance. In the proposed algorithm for three-terminal transmission lines, the faulty section and the location of the fault are determined indirectly by solving optimization functions. The proposed method is tested under various conditions. The obtained results indicate the high accuracy of this method and independence on the type of fault, line parameters, synchronization angle, Thevenin impedance of external networks, fault resistance and incidence angle of fault. Fault locating methods that so far have been provided for multi-terminal transmission lines use synchronized samples of line terminals registered during fault. The proposal in this thesis eliminates the mentioned drawback and unlike conventional algorithms that directly calculate the fault location, the presented method first determines faulty section by solving the optimization functions. Then, the fault point is obtained by solving an optimization function whose decision variables are the location of the fault, as well as the time required for synchronization. Extensive studies confirm that the proposed algorithm can determine the location of faults in multi-terminal transmission lines with high accuracy without the need to classify the type of fault. So far, fault location method for multi-terminal transmission lines that does not need the line parameters and, at the same time, does not need the synchronous data of the transmission line terminals is not published. Hence, in this thesis, an efficient and new fault estimation algorithm for multi-terminal transmission lines is provided that the synchronization angle of the data recorded at the terminals and the values of the transmission line parameters are obtained during the process of determining the fault location. The performance of the proposed method is evaluated. the results demonstrate the high accuracy and validity of the algorithm.
| Item Type: | Thesis (Masters) |
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| Uncontrolled Keywords: | Fault location, multi-terminal transmission line, asynchronous post-fault data, optimization, distributed parameter transmission line model. |
| Subjects: | T Technology > TK Electrical engineering. Electronics Nuclear engineering |
| Depositing User: | Mrs najmeh khajeh |
| Date Deposited: | 10 Apr 2018 04:52 |
| Last Modified: | 06 Mar 2019 07:26 |
| URI: | http://eprints.uoz.ac.ir/id/eprint/2001 |
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