Adaptive Distance Protection Scheme for Mutually Coupled Line
- PDF / 1,355,410 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 61 Downloads / 170 Views
ORIGINAL ARTICLE
Adaptive Distance Protection Scheme for Mutually Coupled Line Uma Uzubi Uma1 · Arthur Ekwue1,2 · Emenike Ejiogu1 Received: 22 April 2020 / Revised: 8 July 2020 / Accepted: 5 October 2020 © The Korean Institute of Electrical Engineers 2020
Abstract The availability of zero-sequence current, under normal circumstances, determines the accuracy of the operation of a distance relay which is connected to a mutually coupled parallel line. When this is not available, the system adopts a different compensation factor which if, not properly calculated introduces errors in the relay operation. The proposed adaptive protection scheme, described in this paper, consists of three modular artificial neural networks model (ANN). This is developed using the feed-forward nonlinear backpropagation Levenberg–Marquardt algorithm that determines the actual status of the mutually coupled lines. The remote terminal units connected to the current and voltage transformers are used to acquire the appropriate data. The proposed scheme also carefully determines the ground distance element reach settings by calculating the apparent impedance while considering mutual coupling for all practical system configurations from the ANN; this eliminates the need for a compensation factor. The results of the apparent impedance (R + jX) calculated by the proposed adaptive and the conventional schemes, showed an average percentage error of (0.06% and 0.02%) and (15% and 41.5%) respectively. Having obtained this result, the performance of the proposed adaptive scheme showed the exact fault location with a higher accuracy when compared with a compensated conventional scheme. Keywords Adaptive relaying · Distance protection · Mutual coupling · Mho characteristic · Artificial neural networks
1 Introduction Most utility companies, for economic reasons and rightsof-way considerations, prefer to use a double circuit transmission line for power transfers rather than construct two separate transmission lines on same corridor. Under such conditions, magnetic mutual induction always occurs in the double and single circuit lines that use the same transmission towers and share the same rights-of-way. It has been a standard practice that distance protection relays are commonly used for the protection of these transmission lines. They calculate line impendence by measuring line voltages * Uma Uzubi Uma [email protected] Arthur Ekwue [email protected] Emenike Ejiogu [email protected] 1
Department of Electrical Engineering, University of Nigeria Nsukka, Nsukka, Enugu State, Nigeria
Africa Center of Excellence on Substainable Power & Energy Development, University of Nigeria Nsukka, Nigeria
2
and currents on one end and compare the impedance with the measured impedance to determine if the fault is within the appropriate protected zone. However, when conventional distance relays are applied to parallel lines its operational performance is adversely affected by the mutual coupling effect between these parallel-coupled lines. T
Data Loading...
