Protect-DG

Uudet tekniikat sähköverkon vikatilanteiden ja

hajautetun tuotannon hallinnassa

19.09.2017

Amir Farughian

Overview

• Single-phase earth fault location

– Review of the existing methods

– Improving a method

• Sequence currents

• PSCAD simulations

• Theoretical analysis

– Earth fault location based on signaling

– Intermittent earth fault

• Publications and reports

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Fault location methods

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Fault location methods

Centralized Methods

Impedance based

Artificial intelligence

Travelling waves

Distributed Methods

Basic Electrical Quantities

Relays

Fault Passage Indicators

Smart Meters

Signalling

Pulse

Non-grid frequency

Fault location methods

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Fault location methods

Centralized Methods

Impedance based

Artificial intelligence

Travelling waves

Distributed Methods

Basic Electrical Quantities

Relays

Fault Passage Indicators

Smart Meters

Signalling

Pulse

Non-grid frequency

Impedance-based methods not promising!

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J. Altonen and A. Wahlroos, "Performance of Modern Fault Passage Indicator Concept," in CIRED

Workshop, Helsinki, 14-15 June 2016.

“Commercial solutions for computational location of single-phase earth faults is not yet

available, regardless of the research and development work done in recent years [1]. Due to

lack of solutions for computational fault location of earth faults, application of Fault Passage

Indicators (FPIs) is

a promising alternative [2].”

But now we have smart grids:

• Good sensors

• Working communication

• IEDs with high sampling rate, etc

Decentralized

methods

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Fault location

using sequence

components

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Basic method

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M. Lehtonen, O. Siirto and . M. F. Abdel-Fattah , "Simple Fault Path Indication Techniques for Earth Faults," in IEEE Electric Power Quality and Supply Reliability Conference (PQ), Rakvere, Estonia, 11-13 June 2014:

Along the fault current path between the feeding substation and the

fault point, the negative sequence component varies only a little but

it is practically non-existent behind the fault.

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Negative sequence component (current)

• Negative sequence current can be obtained from phase

currents

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𝐼𝑛𝑒𝑔 = 1

3 (𝐼𝑎 + 𝑎𝐼𝑏 + 𝑎2𝐼𝑐)

𝑎 = −1

2+ 𝑗

3

2

𝐼𝑎

𝐼𝑏

𝐼𝑐

PSCAD simulations

• Rural

– Isolated

– Compensated

• Urban

– Isolated

– Compensated

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Some PSCAD

simulation results

of the basic

method

(Lehtonen)

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5 km 20 km 35 km 50 km

Background

network Healthy feeder

AHXAMK AL132 Pigeon Raven Primary

transformer

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5 km 20 km 35 km 50 km

Background

network Healthy feeder

AHXAMK AL132 Pigeon Raven Primary

transformer

0 A 0 A 0 A 0 A 0 A

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5 km 20 km 35 km 50 km

Background

network Healthy feeder

AHXAMK AL132 Pigeon Raven Primary

transformer

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5 km 20 km 35 km 50 km

Background

network Healthy feeder

AHXAMK AL132 Pigeon Raven Primary

transformer

44.17 A 0.01

44.13 A 44.21 A 6.24 A 3.07 A

Rf (Ω)

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5 km 20 km 35 km 50 km

Background

network Healthy feeder

AHXAMK AL132 Pigeon Raven Primary

transformer

44.17 A 44.05 A

0.01 1

44.13 A 44.02 A

44.21 A 44.09 A

6.24 A 6.22 A

3.07 A 3.06 A

Rf (Ω)

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5 km 20 km 35 km 50 km

Background

network Healthy feeder

AHXAMK AL132 Pigeon Raven Primary

transformer

44.17 A 44.05 A 42.66 A

0.01 1 10

44.13 A 44.02 A 42.63 A

44.21 A 44.09 A 42.70 A

6.24 A 6.22 A 6.02 A

3.07 A 3.06 A 2.96 A

Rf (Ω)

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5 km 20 km 35 km 50 km

Background

network Healthy feeder

AHXAMK AL132 Pigeon Raven Primary

transformer

44.17 A 44.05 A 42.66 A 23.20 A

0.01 1 10 100

44.13 A 44.02 A 42.63 A 23.18 A

44.21 A 44.09 A 42.70 A 23.22 A

6.24 A 6.22 A 6.02 A 3.27 A

3.07 A 3.06 A 2.96 A 1.61 A

Rf (Ω)

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5 km 20 km 35 km 50 km

Background

network Healthy feeder

AHXAMK AL132 Pigeon Raven Primary

transformer

44.17 A 44.05 A 42.66 A 23.20 A 2.99 A

0.01 1 10 100 1000

44.13 A 44.02 A 42.63 A 23.18 A 2.98 A

44.21 A 44.09 A 42.70 A 23.22 A 2.99 A

6.24 A 6.22 A 6.02 A 3.27 A 0.42 A

3.07 A 3.06 A 2.96 A 1.61 A 0.20 A

Rf (Ω)

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5 km 20 km 35 km 50 km

Background

network Healthy feeder

AHXAMK AL132 Pigeon Raven Primary

transformer

44.17 A 44.05 A 42.66 A 23.20 A 2.99 A

1 A

0.01 1 10 100 1000 3000

44.13 A 44.02 A 42.63 A 23.18 A 2.98 A

1 A

44.21 A 44.09 A 42.70 A 23.22 A 2.99 A

1 A

6.24 A 6.22 A 6.02 A 3.27 A 0.42 A 0.14 A

3.07 A 3.06 A 2.96 A 1.61 A 0.20 A 0.06 A

Rf (Ω)

Improved method

• Invention disclosure

– Addresses the shortcoming of the basic method

• Report

– theoretical analysis

– PSCAD simulations

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Main advantages of the new method

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• Cost-effective No need for voltage measurement. It is based on only

current measurements that can be performed by

Rogowski coil

Compared to signal injection methods, there is no need

for additional injection devices

• Independent of the fault resistance

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Basic method

• The basic method is in use already in urban networks. Its

performance is good as in urban networks the fault

resistance is close to zero ohms.

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Fault location

based on

signaling

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Principles of the method

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G. Druml, C. Raunig, P. Schenger and L. Fickert, "Fast Selective Earth

Fault Localization using the New Fast Pulse Detection Method," in 22nd

International Conference on Electricity Distribution, Stockholm, 10-13

June 2013.

Intermittent Earth

Fault

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Intermittent earth fault location _ possible solution

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Faulted phase currents before and after the fault point

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Publications and reports

• Amir Farughian, Lauri Kumpulainen, Kimmo Kauhaniemi, “Review of

Methodologies for Earth Fault Indication and Location in Compensated and

Unearthed MV Distribution Networks”, Electric Power Systems Research,

2017. (accepted)

• Invention disclosure (waiting for a decision)

• Amir Farughian, Anton Poluektov,… “Earth fault location based on powerline

signaling”, The 14th International Conference on Developments in Power

System Protection, March 2018, Belfast, UK (submitted).

• Sampo Voima, Amir Farughian, “Intermittent Earth Fault Protection and

Location”, June 2017 (report)

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Kiitos!

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