MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

One phase rural distribution installation with direct connection to

HV trunk line

P.A. MONFILS, Jean-Louis LILIEN, A. OMBOUA

2MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

• Scope of the project

• Local conditions

• Makola application

• Load

• Reliability aspects

SUMMARY

3MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

Scope of the project

The problem The solution

4MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

Typical low load user (Makola)

5MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

Refrigerators 3 kVA

Human health center 3

TV and video 2

Private lighting 24

Public lighting 7

Water pumping 3

TOTAL 42 kVA

One 500 people village:Estimated load (UNESCO)

Typical low load user (Makola)

Conclusion: 50 kVA is OK

!

6MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

Local conditions

7MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

Local conditions

• 846 km from the main power supply

• Very low short-circuit level: 360 A

• Very low load: – Frequent over-voltages– Important power availability

50 kVA = 3.10-4 SIL (Surge impedance loading)

• Very high keraunic level (lightning activity)

8MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

Local conditions

• High soil resistivity: > 3000 .m– HV earth resistance: 35– Risks for the inhabitants

• in case of line-to-earth fault• in case of lightning on the HV line

– Needs deep analysis of earthing system

9MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

F ig 5 -5 : C o nfig ura tion du c ircu it A : terre du p ylône B : terre du poste H T C : terre du réseau B T

R T 3

A B C

• Schematic diagram

Makola application

10MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

• SF6 VT technology: high reliability

• Limited maintenance• Limited weight: easy to

transport/handle• Limited cost (no switch

bay)• Direct from 245 kV to

230 V (50 kVA)

Makola application

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Barcelona 12-15 May 2003

Makola application

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Barcelona 12-15 May 2003

Makola application

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Barcelona 12-15 May 2003

Makola application

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Barcelona 12-15 May 2003

Load recording

15MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

Load recording

16MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

Reliability aspects

• Improved technology (SF6 VT) with very limited maintenance

• Immediate protection by ZnO surge arrester• One year experiment: the reliability of the

equipment is much higher than the HV system (min 5 power outages per month)

• Possible improvement by use of HV fuses

17MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

• Improvement of the quality of life of rural populations (< 3% of peoples access electrical power in Congo)

• Electrical energy gives access to drinking water, food preservation, lighting.

• Electrical energy may help starting development of local activities

• Our solution is cost effective, easy to handle and reliable

Conclusions

MONFILS Pierre-André (BE) Session 5 - Block 1 - Question 5.14

Barcelona 12-15 May 2003

Thank you for your attention !