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A System of monitoring of the quality of servicing a licensee of electric power distribution

Advisor to the Chairman - Elizbar EristaviHead of the Department of Certification - Alexander Pirtskhalaishvili

Tbilisi26 June - 3 July, 2008

Georgian National Energy and Water Supply Georgian National Energy and Water Supply Regulatory CommissionRegulatory Commission

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Monitoring of the quality of power supply servicing of Monitoring of the quality of power supply servicing of consumers by a licensee of distributionconsumers by a licensee of distribution

On the basis of the Law of Georgia on Electric Power and Natural Gas, the Department of Certification of the Quality of Servicing of Licensees in Electroenergetics is established within the Commission.

The main function of the Department is monitoring of the quality of services, including registration of indicator of the quality of servicing licensees, revision of materials to be submitted to the Commission and preparation of respective opinions.

In 2005-2007, technical monitoring (selective survey) of the quality of electric power was carried out, mainly within the area of operation of a distribution company in Tbilisi.

Means of control - Alfa-type electric power multifunctional micro-processing meters, installed at high tension sub-stations and power stations, on a medium tension side (6-10 kv).

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Technical monitoringTechnical monitoring

In Georgia, actual electric power parameters are verified against nominal parameters following requirements of the effective normative document Gost 13109-97 (CIS standard harmonized with the relevant European standard).

In accordance with the referred document, two electric power quality norms are defined: Frequency deviation norms:

Allowed nominal 50 + 0,2 hertz. Allowed marginal 50 + 0,4 hertz.

Voltage deviation norms: Allowed nominal + 5,0%. Allowed marginal + 10%.

Alfa type meters also permit obtaining such data as unsymmetrical voltage and currents, voltage and current values, n-harmonic mdgenelis coefficients.

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Monitoring of changeability of some of the key electric

power quality indicators was carried out in 2005-2007, during various seasons, at points of connection of joint stock company Telasi 6-10 kv consumers, at the following energy units located within the territory of Tbilisi region: In Power distribution:

220/110/35/6-10 kv Navtlughi sub-station. 220/110/35/6-10 kv Didube sub-station. 220/110/35/10 kv Gldani sub-station. 220/110/35/10 kv Lisis sub-station.

Power stations: Tetrikhevi HPP Ortachala HPP Zahessi HPP

And also Tsevi sub-station in the area of Zahess settlement.

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Monitoring of electric power quality with consumers of 0,4 kv networks was not carried out due to the absence of electronic meters and power metering tools in these networks.

In a high tension transmission network, the analysis of tables produced as a result of monitoring of changeability of some of the electric power quality indicators suggests the following: at the points of connection of 6-10 kv consumers, electric power quality indicators are in full compliance with gost 13109-97requirements of the effective normative document, which is pre-conditioned by the following factors:

Electro generation sector of the Georgian electric system is at large covering the national demand for the quantity and power of electric energy; At the same time, during the period of monitoring works, power supply system of Georgia with 500 kv intersystem connection, operated in parallel mode with the power supply systems of neighboring countries, greatly contributing to the steady operation of the system.

Structure of loading of the power supply system of Georgia, due to the low industrial potential in the country, is mainly accounted by public utility loadings. That’s why within the area of Tbilisi city, there is low demand for reactive energy, enabling maintenance of nominal tension values and symmetry.

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D Didi Navtlughi network - 110kv egx kenisi-4

As seen from this example, parameters: frequency, symmetrical phase voltage and currents are maintained.

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A system of monitoring of the quality of services of a power A system of monitoring of the quality of services of a power distribution licenseedistribution licensee

Technical monitoring is continued in a limited scope, as power transmission and distribution networks are not equipped with adequate measuring devices. Installation of the Alfa-type power-meters and introduction of the SCADA systems is currently underway.

At the end of 2007, with support of the World Bank, a specialist was invited, who together with the employees of the Commission, worked out recommendations on introduction of monitoring of indicators of the power supply reliability and indicators of the commercial service quality.

The referred recommendations are based on the experience of the advanced European countries.

By order of the Chairman of the Commission, a working group was formed comprising representatives of the Commission and transmission-distribution licensees; This group was commissioned to work out and submit to the Commission relevant draft instructions in order to adopt an appropriate normative document.

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Monitoring of the quality of services Monitoring of the quality of services

This group has worked out two draft instructions: Instructions on monitoring of indicators of the

power supply reliability. Instructions on monitoring of indicators of

commercial services quality.

In the near future, the Commission will submit these instructions for approval at a public session, whereupon they will be introduced into practice.

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Monitoring of the indicators of power supply reliability by a power Monitoring of the indicators of power supply reliability by a power distribution licensee distribution licensee

(registration, reporting, audit)(registration, reporting, audit)

Establishes common rules and requirements with regard to: Registration by a distribution licensee of

information on reliability of power supply. Presentation by a licensee of the processed

information on reliability of power supply (a report) to the Commission.

Analysis and audit of the report data on reliability of power supply presented by a licensee to the Commission.

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Registration of interruptionsRegistration of interruptions

A distribution licensee should record interruptions in power supply in a Registry, including its soft copy.

This Registry should contain the following information with regard to each case of planned and unplanned long-term interruptions (> 3 wT.):

Identification number of interruption. Place of origination of interruption (voltage level). Means of registration of interruption (method). Type of interruption (planned, unplanned). Informing consumers of the planned interruption. Reason of interruption (force majeure, exterior, interior). Beginning of interruption (Date, hour, minute). Recovery of power supply (Date, hour, minute). As a result of interruption, number of high voltage, medium voltage, low voltage

disconnected consumers grouped by levels of accommodation density.

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Indicators of uninterrupted supply of electricity are Indicators of uninterrupted supply of electricity are calculated as followscalculated as follows::

There are following levels of accommodation density: High density – territories of towns. Average density – territories of settlements. Low density – territories of villages.

Voltage levels after interruption: Electric power transmission network (egq) - voltage network above 110. Distribution network.

High voltage (HV) – voltage level > 35kv and < 110 kv. Medium voltage (MV) –voltage level ≥ 1 kv and < 35 kv. Low voltage (LV) –voltage level < 1 kv (in our case - 380/220v).

Indicators of uninterrupted supply of electricity: SAIDI Index – average duration of interruptions in supply of electricity per one

consumer during a reported period (quarter, year). SAIFI Index - average quantity of interruptions in supply of electricity per one

consumer during a reported period (quarter, year).. ENS – quantity of electricity not supplied to consumers due to the interruption

in supply of the electricity.

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Average System Interruption Duration Index per Average System Interruption Duration Index per consumer is specified as follows:consumer is specified as follows:

wherei - series of interruptions in electricity supply (i = 1, . . . k).j - quantity of equal duration і-interruptions

(j = 1, . . . l).ni - number of consumers not supplied electricity due to the equal duration one-

time interruptions (j = 1). ni,j - number of consumers not supplied electricity due to (i) equal duration (j)

many-time interruptions. ti,j - duration of interruption in minutes for ni,j group consumers.N - total number of consumers of a distribution licensee.

N

tnSAIDI

l

jjiji

k

i

1

,,1

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System Average Interruption Frequency System Average Interruption Frequency Index per consumer is specified as follows:Index per consumer is specified as follows:

wherei - series of interruptions in electricity supply (i = 1, . . . k);ni - number of consumers not supplied electricity during one-time

interruption (j = 1);N - Total number of consumers of a licensee.

N

nk

ii

1 SAIFI

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Calculation of the volume of electricity not suppliedCalculation of the volume of electricity not supplied

Volume of the electricity not supplied due to the by Long-tern planned an unplanned і-interruption is calculated using the following formula:

___________________ _____________________ 1 2

This formula consists of two parts: `1~ - volume of electricity not supplied to the medium and low voltage

consumers during a reported period (quarter, year). `2~ - volume of electricity not supplied to the low voltage consumers

during a reported period (quarter, year).

60131400 ENS

1

,i

iii

j

ji tmmPt

n Qi

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wherei - series of duration of interruptions in supply of the electricity (i = 1, . . . k).J - і, Quantity of equal duration interruptions (j = 1, . . . l).Qi,j kvt.sT. – quantity of electricity, which during the reported period was (quarter, year) consumed by the medium and high voltage distribution

network consumers, who were not supplied electricity for і-duration and in j-quantity.

ni - number of medium and high voltage consumers, who were not supplied electricity for equal duration due to the one-time interruptions.

ti wT. – Time of failure in supply of electricity due to і interruption. m – Number of medium and low voltage transformers.mi - number of medium and low voltage transformers failed for equal duration,

due to the one-time interruptions.P kvt. – total capacity of medium / low voltage transformers. η _ Transformer loading coefficient (specified by results of operating loading

measurement).131400 – Average quantity of minutes per quarter (730 X 3 = 2190 hr).

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Form of the Registry of interruptions in electricity supplyForm of the Registry of interruptions in electricity supply

Number of consumers, total

Of which in towns (t)

settlements (s)

villages (v)

ID Registration means

Interruption voltage level

egx- settlement

Reason Date and time of commencement

Date and time of completion

Type of interruption

Disconnected consumer

Electric power not supplied

SAIDI town

SAIDI settlement

SAIDI village

SAIFI town

SAIFI settlement

SAIFI village

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

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Form of submission to the Commission Form of submission to the Commission of reports by a distribution licenseeof reports by a distribution licensee

Reports are presented on a quartely basis, separately for the territories of towns, settlements and villages.

A distribution licensee: AYear: ______ I (II, III, IV) quarterType of interruption: long-term, unplanned

SAIDI Town (settlement, village)

Reason of interruption Eegq

1

HV

2

MV

3

LV

4

Total

5

Force Majeure 1

exterior reasons

interior reasons

3

Total 4

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Form of submission of reports to the Commission Form of submission of reports to the Commission by a distribution licensee by a distribution licensee

Reason of interruption

Eegq

1

HV

2

MV

3

LV

4

Total

5

Force majeure

1

exterior reasons

2

interior reasons

3

Total 4

SAIFI town (settlement, village)

• 1-3 rows contain data of the SAIDI and SAIFI system indexes for those interruptions, which are caused by reason of force majeure (1), exterior reasons (2), interior reasons (3).

• 1-4 columns contain data of the SAIDI and SAIFI system indexes, which are accounted by damage of network elements in transmission network (egq) (1), in HV distribution networks (2), MV distribution networks (3), LV distribution networks (4).

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Revision of the indexes of uninterrupted supply of Revision of the indexes of uninterrupted supply of electric powerelectric power

In order to decide, in course of the revision of the information presented by a licensee, on the correctness of the data presented on reliability of the electric power supply, the following indexes are used: AI (accuracy index); PI (precision index); СI (correctness index).

These indexes are calculated, using any method of data selection.

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Accuracy Index – Accuracy Index – AIAI

Procedure of revision by the Commission of the data on reliability of the electric power supply.

Completeness index AI is used to evaluate completeness of registration of unplanned interruptions in MV networks (all cases of interruption must be recorded). AI may have values from 0 % (minimum completeness) to 100% (maximum completeness).

where: i - different types of incomplete and inaccurate data (Table A). Pi - unit weight of each type of incomplete data (Table A).

00100)1( iPAI

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Table ATable A

iType of inaccurate and incomplete data unplanned interruptions in MV networks

Pi

1 Unregistered interruption 1

2 Commencement of an interruption is registered with more than 30 min variation 0.5

3 Commencement of an interruption is registered with more than 15-30 min variation 0.3

4 Commencement of an interruption is registered with 5-15 min. variation 0.1

5 Commencement of an interruption is registered with 1-5 min. variation 0.05

6 Commencement of an interruption is registered with up to 1 min. variation 0.01

7 Accomplishment of interruption is registered with more than 10 min. variation 0.3

8 Accomplishment of interruption is registered with 1-10 min. variation 0.01

9 Interruption is registered so that it is impossible to verify duration of the interruption, number of consumers not supplied electricity or reason of interruption

0.3

10 Interruptions are registered inaccurately due to other reasons (for instance, two interruptions are registered as one, but correct total duration is indicated; records of superfluous interruptions)

0.1

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Precision IndexPrecision Index _ _ PI PI

Precision index is used to evaluate total variation of data on long-term, unplanned interruptions in MV networks.

PI may acquire a positive or negative value, and in case of max. precision – total 0.

where:Do _ Total duration of interruption per one LV consumer

checked by the Commission (caused by damage of MV networks).

D1 _ Indicator of a total duration of interruption per one LV consumer calculated by a distribution licensee.

% 1001

o

o

DDDPI

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Correctness IndexCorrectness Index _ _ CICI

Correctness index is used to evaluate correctness of the indicated reasons and place (voltage level) of a long-term unplanned interruption in the registration data.

CI may acquire values from 0% to 100%. Index value of 0% indicates complete absence of precision in specification of the force majeure, exterior and interior reasons of interruption, as well as the place of origination (transmission or HV networks). Index value of 100% indicates maximum precision in specification of the reasons and place of interruptions.

Indexes contained in this formula present values derived as a result of comparison of the data on reasons of duration of interruption per one consumer presented by a distribution licensee and the data revised by the Commission in course of an audit.

% 1002

2

DCBA DDDDDDCI

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D2 _ A licensee has relevantly indicated the duration, reason (force majeure, exterior, interior) or place of origination of interruption.

DA _ A licensee has incorrectly indicated force majeure as a reason of a long-term interruption in MV and LV networks, while interruptions were actually caused by other reasons.

DB _ A licensee has incorrectly indicated an interior interruption reason. DC _ A licensee has incorrectly indicated an interior interruption reason. . DD _ A licensee has incorrectly indicated the reason of interruption in HV

distribution network, while interruptions were actually originated in the MV network.

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Commercial qualityCommercial quality

Defines relationship between a consumer and a distribution licensee. Monitoring of the commercial services quality means:

Registration of information on commercial services quality by a licensee.

Processing and presentation to the Commission of the information received by a licensee.

Audit of a report presented to the Commission

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Registration of informationRegistration of information A distribution licensee must maintain a Registry of applications of consumers for

delivery of services, including its soft copy. This Registry shall contain the following information with regard to each

application: Identification number of application for delivery of services submitted by a

consumer. Title of services (or code). Category of services (Communal LV, non-communal LV/ MV consumer). Identification (subscription) data of a consumer. Date of submission of an application for delivery of services by a consumer. Date of presentation of an application for authorization to deliver services

and date of obtaining such authorization. Date of accomplishment of the works responsibility for which rests with a

consumer. Date of accomplishment of delivery of services. Reasons of failure to comply with the conditions of services. Reason and date of refusal to deliver services.

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Commercial services quality standardsCommercial services quality standards Services Quality requirements (standards)

A well-grounded answer to the written application of a consumer Communal _ no more than 8 working days

Non-communal _ no more than 10 working days

Informing consumers on the planned interruption in electric power supply

Communal _ no more than 3 working days

Non-communal _ no more than 5 working days

Evaluation of the cost of works to be performed For simple work _ no more than 3 working days

For complex work _ no more than 10 working days

Performance of works For simple work _ no more than 3 working days

For complex work _ time specified by pr. documentation,

Connection of a new consumer to the network no more than 3 working days

Connection of a consumer cut off due to non-payment No more than 1 day from the date of settlement

On the basis of an application of a consumer, revising of the sum charged

No more than 5 days from the date of submission of an application

On the basis of an application of a consumer, revision of the quality of voltage (deviations from nominal values, jitter)

Visit to a consumer for explanation – no more than 3 working days

On the basis of an application of a consumer, inspection of his metering device

Fr simple inspection (for instance, counting turnover frequencies) _ from the date of submission of an application

no more than 2 working days

To replace a damaged, inaccurate or not operating device – no more than 5 working days

Time of responding of a call- center operator, by hot line 20 sec.

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Conclusion:Conclusion:

The Commission plans to approve the above-reffered instructions by 1 September of the current year.

Transmission-distribution licensees got familiar with the draft instructions and during working meeting expressed their readiness to introduce the system of servicing quality indicators.

At the initial stage, requirements of the referred instructions will be introduced, approximately during 6 - 9 months, under support of the Department of Certification of the Commission. During this period only data verification will be done.

At the next stage, incentives or/and sanctions will be introduced.

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Thank you for attention