IEC61850 standard-based harmonic blocking scheme for power transformers

Senthil Krishnamurthy,Bwandakassy Elenga Baningobera

doi:10.1186/s41601-019-0123-7

Senthil Krishnamurthy, Bwandakassy Elenga Baningobera

Open Access

https://doi.org/10.1186/s41601-019-0123-7

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Abstract

Transformer Differential and overcurrent schemes are traditionally used as main and backup protection respectively. The differential protection relay (SEL487E) has dedicated harmonic restraint function which blocks the relay tripping during the transformer magnetizing inrush conditions. However, the backup overcurrent relay (SEL751A) applied to the transformer protection does not have harmonic restraint element and trip the overcurrent relay during the inrush conditions. Therefore, major contribution of this research work is the developed harmonic blocking scheme for transformer which uses element (87HB) of the transformer differential relay (SEL487E) to send an IEC61850 GOOSE-based harmonic blocking signal to the backup overcurrent relay (SEL751A) to inhibit from tripping during the transformer magnetizing inrush current conditions. The simulation results proved that IEC61850 standard-based protection scheme is faster than the hardwired signals. Therefore, the speed and reliability of the transformer scheme are improved using the IEC61850 standard-based GOOSE applications.

Highlights

Transformer failures can be very expensive such as the cost of repairing the transformer, the cost of energy not delivered because of transformer unavailability, and the possible additional cost on spreading damage to adjacent equipment or of a significant power system blackout.Transformers failures are dangerous
This paper provides the test bench implementation for the harmonic blocking scheme using both hardwired DC signal and IEC 61850 standard-based Generic Object-Oriented Substation Event (GOOSE) message
8 Conclusion The IEC 61850 GOOSE message and hardwired signals-based simulation study was conducted in the lab, and various faults pertaining to power transformers were simulated using the omicron test injection device, and relay performance was monitored

Summary

Introduction

Transformer failures can be very expensive such as the cost of repairing the transformer, the cost of energy not delivered because of transformer unavailability, and the possible additional cost on spreading damage to adjacent equipment or of a significant power system blackout.Transformers failures are dangerous. The research work reported in [9] implemented IEC61850 standard-based differential protection scheme which sent harmonic blocking signal to backup overcurrent relay during inrush current conditions to improve the speed and reliability of the backup protection.

Results

Conclusion