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RISS 인기검색어
- 검색키워드
- 저자 : Uma Uzubi Uma (검색결과 2 건)
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Adaptive Distance Protection Scheme for Mutually Coupled Line
Uma Uzubi Uma,Arthur Ekwue,Emenike Ejiogu 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.1
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 diff erent 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 artifi cial 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 confi gurations 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
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Adaptive Distance Protection Scheme Setting in Presence of SVC Using Remote Terminal Unit
Uma Uma Uzubi,Ekwue Arthur,Nmadu Daniel,Eli-Chukwu Ngozi Clara 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.4
FACTS devices are presently used to improve the power transfer capability of a transmission line and voltage stability of a power system network. Shunt injected current (I sh ) by the Static Var Compensators (SVC) causes underreach or overreach of distance relay when not considered during relay calibration of protection system. This paper presents an adaptive relay setting procedure in the presence of a SVC connected at the midpoint of a transmission line. The remote terminal unit RTU is connected to the SVC terminal via a current transformer (CT) measures the injected shunt current when the SVC is the switch in or out of the network and transferred the measured value to the local station via fi ber optic. The PSCAD/ EMTDC software is used to model an adaptive relay that implements the conventional and adaptive relay system settings. The proposed scheme presents a hybrid distance protection system whose setting is based on the prevailing SVC switching conditions; the relay system was implemented using mho characteristics relay. The results obtained show that the proposed scheme has a high accurate setting
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