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An improved fault detection classification and location scheme based on wavelet transform and artificial neural network for six phase transmission line using single end data only.

Koley E, Verma K, Ghosh S - Springerplus (2015)

Bottom Line: The proposed scheme has been tested for all 120 types of shunt faults with variation in location, fault resistance, fault inception angles.The variation in power system parameters viz. short circuit capacity of the source and its X/R ratio, voltage, frequency and CT saturation has also been investigated.The result confirms the effectiveness and reliability of the proposed protection scheme which makes it ideal for real time implementation.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, National Institute of Technology, G.E. Road, Raipur, 492010 India.

ABSTRACT
Restrictions on right of way and increasing power demand has boosted development of six phase transmission. It offers a viable alternative for transmitting more power, without major modification in existing structure of three phase double circuit transmission system. Inspite of the advantages, low acceptance of six phase system is attributed to the unavailability of a proper protection scheme. The complexity arising from large number of possible faults in six phase lines makes the protection quite challenging. The proposed work presents a hybrid wavelet transform and modular artificial neural network based fault detector, classifier and locator for six phase lines using single end data only. The standard deviation of the approximate coefficients of voltage and current signals obtained using discrete wavelet transform are applied as input to the modular artificial neural network for fault classification and location. The proposed scheme has been tested for all 120 types of shunt faults with variation in location, fault resistance, fault inception angles. The variation in power system parameters viz. short circuit capacity of the source and its X/R ratio, voltage, frequency and CT saturation has also been investigated. The result confirms the effectiveness and reliability of the proposed protection scheme which makes it ideal for real time implementation.

No MeSH data available.


Related in: MedlinePlus

a Six phase current waveform during “fg” fault at La = 1 km, Rf = 0 Ω and Φi = 0º without CT saturation. b Six phase current waveform during “fg” fault at La = 1 km, Rf = 0 Ω and Φi = 0º with CT saturation
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Fig8: a Six phase current waveform during “fg” fault at La = 1 km, Rf = 0 Ω and Φi = 0º without CT saturation. b Six phase current waveform during “fg” fault at La = 1 km, Rf = 0 Ω and Φi = 0º with CT saturation

Mentions: Transmission line protection primarily uses current transformers for measuring the current in the line. During a short circuit, the large current containing a significant DC component may lead to current transformer (CT) saturation. The saturation leads to a distorted secondary current. A proper protection scheme should operate even under CT saturation. Under such condition differential protection systems may result in undesirable tripping; overcurrent or distance relays may underreach or fail to operate, in extreme cases. It is required to check the appropriateness of the proposed scheme under the condition of distorted secondary current, arising out of CT saturation in order for line protection to operate or restrain as required. For this purpose simulations were carried out to evaluate the impact of current transformer saturation on the performance of proposed protection scheme. Figure 8 shows the comparison of the instantaneous current waveforms of phase ‘f’ without and with CT saturation during single phase to ground fault i.e. ‘fg’ fault at 1 km from relaying point with Rf = 0 Ω and Φi = 0° (ti = 0.033 s.). After the occurrence of fault, the asymmetry in the current waveform during the transient period is solely attributed to CT saturation.Fig. 8


An improved fault detection classification and location scheme based on wavelet transform and artificial neural network for six phase transmission line using single end data only.

Koley E, Verma K, Ghosh S - Springerplus (2015)

a Six phase current waveform during “fg” fault at La = 1 km, Rf = 0 Ω and Φi = 0º without CT saturation. b Six phase current waveform during “fg” fault at La = 1 km, Rf = 0 Ω and Φi = 0º with CT saturation
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4583559&req=5

Fig8: a Six phase current waveform during “fg” fault at La = 1 km, Rf = 0 Ω and Φi = 0º without CT saturation. b Six phase current waveform during “fg” fault at La = 1 km, Rf = 0 Ω and Φi = 0º with CT saturation
Mentions: Transmission line protection primarily uses current transformers for measuring the current in the line. During a short circuit, the large current containing a significant DC component may lead to current transformer (CT) saturation. The saturation leads to a distorted secondary current. A proper protection scheme should operate even under CT saturation. Under such condition differential protection systems may result in undesirable tripping; overcurrent or distance relays may underreach or fail to operate, in extreme cases. It is required to check the appropriateness of the proposed scheme under the condition of distorted secondary current, arising out of CT saturation in order for line protection to operate or restrain as required. For this purpose simulations were carried out to evaluate the impact of current transformer saturation on the performance of proposed protection scheme. Figure 8 shows the comparison of the instantaneous current waveforms of phase ‘f’ without and with CT saturation during single phase to ground fault i.e. ‘fg’ fault at 1 km from relaying point with Rf = 0 Ω and Φi = 0° (ti = 0.033 s.). After the occurrence of fault, the asymmetry in the current waveform during the transient period is solely attributed to CT saturation.Fig. 8

Bottom Line: The proposed scheme has been tested for all 120 types of shunt faults with variation in location, fault resistance, fault inception angles.The variation in power system parameters viz. short circuit capacity of the source and its X/R ratio, voltage, frequency and CT saturation has also been investigated.The result confirms the effectiveness and reliability of the proposed protection scheme which makes it ideal for real time implementation.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, National Institute of Technology, G.E. Road, Raipur, 492010 India.

ABSTRACT
Restrictions on right of way and increasing power demand has boosted development of six phase transmission. It offers a viable alternative for transmitting more power, without major modification in existing structure of three phase double circuit transmission system. Inspite of the advantages, low acceptance of six phase system is attributed to the unavailability of a proper protection scheme. The complexity arising from large number of possible faults in six phase lines makes the protection quite challenging. The proposed work presents a hybrid wavelet transform and modular artificial neural network based fault detector, classifier and locator for six phase lines using single end data only. The standard deviation of the approximate coefficients of voltage and current signals obtained using discrete wavelet transform are applied as input to the modular artificial neural network for fault classification and location. The proposed scheme has been tested for all 120 types of shunt faults with variation in location, fault resistance, fault inception angles. The variation in power system parameters viz. short circuit capacity of the source and its X/R ratio, voltage, frequency and CT saturation has also been investigated. The result confirms the effectiveness and reliability of the proposed protection scheme which makes it ideal for real time implementation.

No MeSH data available.


Related in: MedlinePlus