technical performance indicators - kostt

TECHNICAL PERFORMANCE INDICATORS

September 2007

Prishtina

TABLE OF CONTENTS

1. Introduction ...................................................................................... 2

2. Technical Key Performance Indicators .......................................... 3 2.1. Output of a TSO ...................................................................................... 3 2.1.1. Transmitted electricity (GWh)........................................................................ 3 2.1.2. Coincident Peak demand (MW) .................................................................... 6 2.1.3. Length of the lines (km)................................................................................. 7 2.1.4. MVA-km......................................................................................................... 8 2.1.5. Capacity of Transformers .............................................................................. 8 2.2. Fulfillment of Market Request ............................................................... 9 2.2.1. Average Available Import/Export capacity (NTC)........................................ 10 2.2.2. Maximum Available Import/Export capacity (NTC)...................................... 11 2.2.3. Congestion rent ........................................................................................... 11 2.3. Quality of the Transmission Function of a TSO: Network Reliability

................................................................................................................ 12 2.3.1. Average Interruption Time (AIT) .................................................................. 12 2.4. Commercial Quality: Voltage and Metering Complaints................... 13 2.4.1. Number of Voltage Complaints ................................................................... 13 2.4.2. Number of Voltage Complaints resolved within a specified number of days

.................................................................................................................... 15 2.4.3. Number of Metering Complaints.................................................................. 16 2.4.4. Metering Complaints resolved within a specified number of days............... 16 2.5. Quality of System Operation ............................................................... 17 2.5.1. Average absolute deviation of Hourly Import/Export Schedule ................... 17 2.6. Network Losses .................................................................................... 18 2.6.1. Network Losses (GWh) ............................................................................... 19 2.7. Internal Technical Performance .......................................................... 20 2.7.1. Line/ Cable Failure rate per 100 circuit km.................................................. 20 2.7.2. Average repair time of Line/Cable failures .................................................. 21 2.7.3. Average Outage time due to Line/Cable maintenance................................ 21 2.7.4. Transformer Failure rate per 100 Transformers .......................................... 22 2.7.5. Average repair time of Transformer failures................................................ 22 2.7.6. Average Outage time due to Transformer maintenance ............................. 23 2.7.7. Switchgear Failure rate per 100 bays.......................................................... 24

Technical Performance Indicators i

2.7.8. Average repair time of Switchgear failures.................................................. 24 2.7.9. Average Outage time due to Switchgear maintenance ............................... 25 2.7.10. Control/Protection Failure rate per 100 bays............................................... 26 2.7.11. Average repair time of Control/Protection failures....................................... 26 2.7.12. Average Outage time due to Control/Protection maintenance .................... 27

Technical Performance Indicators ii

ABBREVIATIONS

AIT - Average Interruption Time

ATC - Available Transfer Capacity

MATC – Maximum Available Transfer Capacity

AATC – Average Available Transfer Capacity

KPI - Key Performance Indicator

NTC - Network Transmission Capacity

TSO - Transmission System Operator

TS - Transmission System

TPI - Technical Performance Indicator

Technical Performance Indicators 1

1. Introduction Regard to Article 16 of the License Overall and Minimum Standards of Performance of the Transmission Operation Business. TSO is obliged to establish and maintain and monitor compliance with regard to the transmission system performance.

Also Article 46.2 of the Law of Regulator stipulates the tariff methodology shall be based on the principle to establish performance based rates.

These indicators measure the reliability of electric power service and reflect operational problems.

Technical performance indicators provide information on standards of performance offered to customers, including the quality of services and security and reliability of supply.

The objective of this document is to present the technical KPI and which set of data will be needed, which will be presented in the following format:

Table 1: Example for the description of selected technical KPI

Title of KPI N° T1

Definition

Formula/Data measurement

Target

.


2. Technical Key Performance Indicators This chapter provides the definition of the technical key performance indicators. Technical Performance Indicators (TPIs) focus on performance of the power system operated by KOSTT. The Transmission System Operators do have two basic tasks: Transmission Operation and System Operation. Where Transmission Operation has mainly to do with the physical Transmission network, System Operation has to deal with keeping the balance between load and generation. More technically, Transmission Operations has to do with parameters like Voltage, Current, MVA, power factor where System Operations has to do with frequency, MW, load balance etc.

2.1. Output of a TSO

Transmitted electricity (GWh) (section 2.1.1) and Coincident Peak demand (MW) (section 2.1.2) are among the most commonly used parameters to describe the output of a TSO. These KPIs are used by virtually all TSOs and are easy to gather by using commercial metering and/or SCADA systems. Moreover, it’s easy to define them unambiguously which makes them very suitable for comparing them to other countries and to understand them. Last but not least, these figures directly relate to the income of KOSTT, which makes them important Key Performance Indicators. Also Length of the lines (km) (section 2.1.3), MVA-km (section 2.1.4) and Capacity of Transformers (section 2.1.5) are often used and published by other TSOs and a good reference when comparing other values.

2.1.1 Transmitted electricity (GWh)

N° T1 Transmitted electricity (GWh)

Definition


The Transmitted electricity is defined as the electricity (in GWh) transmitted to customers during the reporting period through the transmission system operated by the TSO. This includes transmission system losses and export over interconnections. This definition is shown graphically in Figure 1.

G

G G G

Transmission

Distribution

Distribution end-users

ExportTransmission End-users

Losses

Import

Losses

G

G G G

Transmission

Distribution



Losses

Import

Losses

GG

G G GGG GG GG

Transmission

Distribution



Losses

Import

Losses

Figure 1: Transmitted Electricity should be calculated by adding up all electricity (in GWh) flowing across the dotted line during the reporting period.

The value should be equal to generation infeed into the transmission system plus import over interconnectors as shown in Figure 2.

G

G G G

Transmission

Distribution



Losses

Import

Losses

G

G G G

Transmission

Distribution



Losses

Import

Losses

GG

G G GGG GG GG

Transmission

Distribution



Losses

Import

Losses

Figure 2: Transmitted Electricity should be calculated by adding up all electricity (in GWh) flowing across the dotted line during the reporting period.


The following methodology is used for measuring Transmitted Energy:

• Transmitted Electricity will be metered hourly by kWh metering equipment (interval


meters), installed on the borders of KOSTT’s network;

• The hourly meter readings will be corrected for the fact that they are not installed exactly on the border of KOSTT’s network;

• For all hours during the reporting period, the Transmitted Energy will be calculated, using the following formula (see also Figure 1 and Figure 2 above):

users_Load-on_EndTransmissi nergyExported_Ed_EnergyTransmitte +=1

Losseson_System_Transmission_LoadDistributi ++

or EnergyGenerated_ nergyImported_Ed_EnergyTransmitte +=

2

Target

This performance indicator tells more about exogenous effects on KOSTT than about the performance of KOSTT itself, since all individual parameters out of which the Transmitted Energy is calculated (Import, Export, generation and load) are heavily dependent on how market participants are acting on the market. However, KOSTT will try to influence this a bit by making as much transmission capacity available on its network as possible. Most important reason for collecting Transmitted Energy though is that this figure provides a reference figure which could be used for comparing other KPIs historically and with similar KPIs of other TSOs. Therefore, we propose not defining a target for this KPI.

1 Including Load from generators in case their load is larger than their generation (i.e. net importers).

2 Including Generation in distribution and transmission end-users in case their generation exceeds their load (i.e. net exporters).


2.1.2 Coincident Peak demand (MW)

N° T2 Coincident Peak demand (MW)

Definition

KPI T2a: Coincident Peak demand (MW) including transit

Coincident Peak demand (MW) is defined as the coincident National Peak load of the transmission system in the reporting period and includes only load transmitted in the system that is the responsibility of the TSO and that is supplied to the Distribution System, Transmission end users and Export should be reported. This is similar to the examples shown in Figure 1 and Figure 2 above.

KPI T2b: National Coincident Peak demand (MW) excluding transit

This figure is similar to the Coincident peak described above, but excludes and transit flows, like shown in Figure 3.

Figure 3: The Sum of Electricity flowing across the dotted line indicates the alternative for Peak Demand in which Export, Import and Transit flows are excluded.

G

G G G

Transmission

Distribution


Export

Transmission End-users

Losses

Import

Losses

GG

G G GGG GG GG

Transmission

Distribution


Export

Transmission End-users

Losses

Import

Losses



The following methodology is used for measuring Coincident Peak demand (MW) start with the same steps as for KPI T1 Transmitted electricity (GWh):

• Transmitted Electricity will be metered hourly by kWh metering equipment, installed on the borders of KOSTT’s network;

• The hourly meter readings will be corrected for the fact that they are not installed exactly on the border of KOSTT’s network;

• For all hours during the reporting period, the Transmitted Energy will be calculated, using the following formula (see also Figure 1 and Figure 2 above):

users_Load-on_EndTransmissi nergyExported_Ed_EnergyTransmitte +=3

Losseson_System_Transmission_LoadDistributi ++

or EnergyGenerated_ nergyImported_Ed_EnergyTransmitte +=

4

Target

For similar reasons as mentioned in section 2.1.1 for Transmitted Energy, a target is not applicable for Coincident Peak demand.

2.1.3 Length of the lines (km)

N° T3 Length of the lines (km)

Definition

The total circuit length is defined as the sum of the total length of all circuits operated at this Voltage level. A circuit is a single three phase-connection. This means that double circuits (if any), will be counted as twice their route length.

Will be collected for 380 kV, 220 kV and 110 kV separately

3 Including Load from generators in case their load is larger than their generation (i.e. net importers).

4 Including Generation in distribution and transmission end-users in case their generation exceeds their load (i.e. net exporters).



∑=

⋅=level Voltage atlines alli

iilevel Voltage circuitsnumber_of_throute_lenguit_LengthTotal_Circ

Target

A target could be set for each year for building new lines or rebuilding/reconstructing lines which are currently not in operation.

This target will be defined in conjunction with the TNDP and the Transmission Investment Programme.

2.1.4 MVA-km

MVA-km N° T4

Definition

MVA.km indicates the installed capacity of the lines, taking into account the length as well. MVA-km is defined as the sum of the product of length and rated capacity of all circuits operated at this Voltage level. A circuit is a single three phase-connection and double circuits (if any), will be counted as twice their route length.

Will be collected for 380 kV, 220 kV and 110 kV separately


∑=

⋅⋅=level Voltage atlines alli

iiilevel Voltage circuit of r_rated_powecircuitsnumber_of_throute_lengkm-MVA

Target

A target could be set for each year for building new lines or rebuilding/reconstructing lines which are currently not in operation. This target should be based on transmission development plan.

2.1.5 Capacity of Transformers

N° T5 Capacity of Transformers


Definition

Transformer Capacity indicates how much electricity could be transported between the Voltage levels. Transformer Capacity is defined as the total rated capacity of all High Voltage windings of Transformers.

Will be collected for 380-220/110 kV5 transformers and 220-110 kV transformers separately


∑=

=step Voltage atrs transforme alli

step Voltagemersf_TransforCapacity_o windingVoltageHighpowerrated ____

Target

A target could be set for each year for installing new transformers. This target should be based on transmission development plan.

2.2. Fulfilment of Market Request

Since KOSTT is currently calculating the capacity which is available for trade with other countries and starts allocating these capacity to the market (NTC), Average Available Import/Export capacity (AATC) (section 2.2.1) and Maximum Available Import/Export capacity (MATC) (section 2.2.2.) are easily available and provide information about serving the market participants with both import and export capacity. The figures are easily understandable and trends over some years provide information about progress KOSTT makes in this. We therefore selected these KPIs. We selected Congestion rent (section 2.2.3) as well. This value represents the seriousness of the congestion on each border.

Congestion rent is considered a useful indicator

5 Transformers which transform 380 to 220 kV and/or 110 kV.


In accordance to the ETSO report “Definition of Transfer Capacities, 2001, NTC stands for Net Transfer Capacity (and is defined as NTC = TTC – TRM),

Whereas, ATC stands for Available Transfer Capacity (and is defined as ATC = NTC – AAC)

Where:

TTC: Total Transfer Capacity

TRM: Transmission Reliability Margin

AAC: Already Allocated Capacity

In general terms NTC (Net Transfer Capacity) is a quite static value which depends on the improvement of the power system condition and therefore and easily be monitored over an annual basis. On the contrary, ATC is somewhat more dynamic value and thus only average, min and max values are considered meaningful for understanding the conditions of market operation but they not particularly retrospective for the effectiveness of the TSO.

2.2.1 Average Available Import/Export capacity (AATC)

N° T6 Average Available Import/Export capacity (AATC)

Definition

Average Available Import/Export capacity (per border) indicates how much energy can be exported or imported during the reporting period. Average Available Import/Export capacity is defined as the average of all hourly NTC values for this border during the reporting period.


periodreportinginhoursofnumber

CapacityimportAvailablecapacityimportAvailableAverage periodreportinginhoursi

border

border _____

_____ ___

∑==

periodreportinginhoursofnumber

CapacityExportAvailablecapacityExportAvailableAverage periodreportinginhoursi

border

border _____

_____ ___

∑==

Target


According to EU-directives, it is TSOs task to optimally fulfil the requests of the market. If there exists a demand for more import/export capacity a TSO shall develop plans for increasing these, together with its neighbours. A target could be set for this, but should be based on the requirements of the market and the transmission development plan.

2.2.2 Maximum Available Import/Export capacity (MATC)

N° T7 Maximum Available Import/Export capacity (MATC)

Definition

Maximum Available Import/Export capacity indicates how much energy can be transported during the reporting period. Maximum Available Import/Export capacity is defined as the maximum of all hourly NTC values for this border during the reporting period.


( )borderhoursall

border capacityimportAvailablecapacityimportAvailableMaximum MAX ______

=

( )borderhoursall

border capacityExportAvailablecapacityExportAvailableMaximum MAX ______

=

Target

According to EU-directives, it is TSOs task to optimally fulfil the requests of the market. If there exists a demand for more import/export capacity a TSO shall develop plans for increasing these, together with its neighbours. A target could be set for this, but should be based on the requirements of the market and the transmission development plan.

2.2.3 Congestion rent

N° T8 Congestion rent

Definition


If the cross border capacity is allocated to market participants using market mechanisms, congestion rent provides an indication of the value of the cross-border capacity. Congestion rent is defined as the total income from market mechanisms on import/export on this

border.*


∑=

=periodreportinginhoursi

borderborder mechanismmarketfromimportIncomeimportrentCongestion___

______

∑=

=periodreportinginhoursi

borderborder mechanismmarketfromExportIncomeExportrentCongestion___

______

Target

According to EU-directives, it is TSOs task to optimally fulfil the requests of the market. If there exists congestion rent, there is a demand for more import/export capacity a TSO shall develop plans for increasing these, together with its neighbours. A target could be that congestion rent should be reduced.

* KOSTT will start when ATCs are allocated by MO/ checked by SO for technical TTC. Actually Congestion Rent is nil. Therefore (not yet meaning full). Does not have a meaning at the moment.

2.3. Quality of the Transmission Function of a TSO: Network Reliability As an indicator for quality of KOSTT’s transmission network, we selected the Average Interruption Time (AIT) (section 2.3.1) since this parameter defined unambiguously and used more and more by European TSOs.

2.3.1 Average Interruption Time (AIT)

N° T9 Average Interruption Time (AIT)

Definition


The Average Interruption Time (AIT) is comparable to SAIDI. However, the average duration of an outage is not weighted by the number of customers, but by the amount of not supplied energy due to the outage. AIT is defined as the total amount of energy which is not supplied due to outages in the Transmission System, divided by the transmitted energy (see section 2.1.1) in the system, normalized on minutes per year.


EnergydTransmitteSuppliedNotEnergyTimeonInterruptiAverage

___.60.8760__ =

in which Energy_Not_Supplied is defined as:

∑=

⋅=outagesalli

ii powerdInterruptetimenrestoratioSuppliedNotEnergy_

____

Target

A realistic target can only be set when some history is known.

2.4. Commercial Quality: Voltage and Metering Complaints Complaints and resolving complaints should have first attention of the management of KOSTT. Therefore number of Voltage and Metering complaints is in the same order of magnitude as similar numbers for Distribution, we do think that these numbers are essential for judging the quality of the service provided by KOSTT.

2.4.1 Number of Voltage Complaints

N° T10 Number of Voltage Complaints

Definition


The Number of Voltage Complaints is counted as the number of all complaints on Quality of Voltage (e.g. Voltage too low/high, too much Harmonic Distortion) issued by the clients via mail, email and/or telephone during the reporting period. A complaint which is issued several times is only counted once. However, each complaint of a single client is counted, i.e. a client can issue more than one complaint on several events.


The number of Voltage complaints from the complaint database should be counted for the reporting period.

Target

The target for Voltage complaints should be related to the number of complaints in the previous year(s).


2.4.2 Number of Voltage Complaints resolved within a specified number of days

N° T11 Number of Voltage Complaints resolved within a specified number of days

Definition

Of the Voltage complaints counted in the Number of Voltage complaints (section 2.4.1) the time for resolving the complaints is measured and categorized. Three categories are used:

• Resolved within one week;

• Resolved within one month;

• Not resolved within one month.

Resolved means that it is either concluded that the client’s Voltage is not exceeding the Grid Code standards or that the client is the cause of the Voltage problems or that KOSTT has taken measures in order to have the clients Voltage compliant to the standards again.


The Number of Voltage Complaints resolved within a specified number of days should be addressed in the complaint database and counted for the reporting period.

Target

The target for resolving Voltage complaints should be as short as possible. This means that the higher the percentage in the first category, the better.


2.4.3 Number of Metering Complaints

N° T12 Number of Metering Complaints

Definition

The Number of Metering Complaints is counted as the number of all complaints on Metering issues (e.g. wrong metering values used in invoices), issued by the clients via mail, email and/or telephone during the reporting period. A complaint which is issued several times is only counted once. However, each complaint of a single client is counted individually, i.e. a client can issue more than one complaint on several events.


The number of Metering complaints from the complaint database should be counted for the reporting period.

Target

The target for Metering complaints should be related to the number of complaints in the previous year(s).

2.4.4 Metering Complaints resolved within a specified number of days

N° T13 Number of Metering Complaints resolved within a specified number of days

Definition

Of the Metering complaints counted in the Number of Metering complaints (section 2.4.3) the time for resolving the complaints is measured and categorized. Three categories are used:

• Resolved within one week;

• Resolved within one month;

• Not resolved within one month.

Resolved means that it is either concluded that the client’s Metering is not exceeding the Grid Code standards or that the client is the cause of the Metering problems or that KOSTT has taken measures in order to have the clients Metering compliant to the standards again.



The Number of Metering Complaints resolved within a specified number of days should be addressed in the complaint database and counted for the reporting period.

Target

The target for resolving Metering complaints should be as short as possible. This means that the higher the percentage in the first category, the better.

2.5. Quality of System Operation

Control center staff is currently focusing on keeping the hourly balance between load, generation, import and export. Main controls of the staff are control of generator units and load shedding schemes. It is the challenge to the KOSTT staff to keep the hourly balance as good as possible.

2.5.1 Average absolute deviation of Hourly Import/Export Schedule

N° T14 Average absolute deviation of Hourly Import/Export Schedule (MWh/hour)

Definition

The Average absolute deviation of Hourly Import/Export Schedule is defined as the average of all hourly values of the absolute deviation in MWh/hour of the Import/Export schedule with the actual realization.


The Average absolute deviation of Hourly Import/Export Schedule is calculated by the following steps:

• For every hour in the reporting period the Scheduled Import/Export balance is calculated by using the following formula:

hourhourhour ExportScheduledimportScheduledbalanceExportimportScheduled ___/_ −=

(Scheduled import and exports are taken from day ahead schedules which are agreed with neighbouring TSOs)

• For every hour in the reporting period the Realised Import/Export balance is calculated


by using the following formula:

hourhourhour ExportMeteredimportMeteredbalanceExportimportrealised ___/_ −=

(Metered import and exports are taken from metered values on the borders of Kosovo, corrected for the fact that meters are not installed exactly at Kosovo’s borders.

• For every hour the absolute difference between schedule and realisation is calculated by the following formula:

=hournrealisatioScheduledifferenceAbsolute ___

hourhour balanceExportimportscheduledbalanceExportimportrealised _/__/_ −

• For the reporting period the Average absolute deviation of Hourly Import/Export Schedule is now determined by the following formula:

periodreportinginhoursofnumbertotal

nrealisatioScheduldifferenceAbsoluteExportimporthourlyofdeviationabsoluteAverage eriodreportingpinhoursi

______

___/_____ __

∑==

Target

The control centre staff is aiming for the lowest possible Average absolute deviation of Hourly Import/Export Schedule. However, a target should be realistic and based on realization in previous years.

2.6. Network Losses

A significant part of the costs for the transmission of electricity is due to electricity losses in the electricity network. Depending on the size and the transports in the transmission usually several percent of the electricity is lost.

Electricity losses are usually divided into several parts: commercial losses and technical losses. Commercial losses are losses due to theft of electricity but they can originate from insufficient metering & billing procedures, payment collection deficiencies, public administration charges exceptions, etc). This type of losses can be a big problem in distribution networks, but is usually limited for Transmission. For this reason, for KOSTT we will not concentrate on a separation between technical and commercial losses.

In calculation of total losses are also include and those incurred by transit flows.


2.6.1 Network Losses (GWh)

N° T15 Network Losses

Definition

Network Losses are the total of all energy losses in GWh over all voltage levels of the transmission system during the reporting period.


Network Losses are determined using the following steps:

• For every hour, the difference between electricity flowing in the network and electricity flowing out the network is determined by reading all meters:

∑ ∑= =

−=metersInflowalli metersOutflowalli

ihourihourhour OutflowInflowOutflowInflowDifference__ __

,,/_

• For the total reporting period all hourly values are accumulated:

∑=

=periodreportinginhoursalli

iOutflowInflowDifferenceLossesNetwork____

/__

Network Losses in percentage are expressed as:

LossesNetwork _ (%) = %100/_

,__

____ ⋅

∑

∑

=

=

ihourmetersInflowalli

periodreportinginhoursallii

Inflow

OutflowInflowDifference

Target

Network losses cannot be entirely influenced by the KOSTT, because they are largely dependent on the flows in the network. Facilitation of larger electricity flows, which is desired, leads to higher network losses as well. For that reason, it is not realistic to set a target here.


2.7. Internal Technical Performance Since internal quality is the basis for external quality, it is important to keep track of all faults in the network and categorize them to equipment. Although the size of the KOSTT network will probably not allow for a full statistical analyze, trends could become visible when reviewing the figures over some years. In case of a serious increase in failure rate or average repair time, this should be identified using KPIs by the management that is able to address this issue. For this reason, these parameters will be collected. However, these parameters should be collected as background information rather than as global KPIs, since they are not directly reflecting output quality of KOSTT. I.e. if a failure does not lead to an outage the clients will not face a decrease in quality. However, for the management this information could be very useful for identifying trends.

2.7.1 Line/ Cable Failure rate per 100 circuit km

N° IT1 Line/ Cable Failure rate per 100 circuit km

Definition

Line/ Cable Failure rate per 100 circuit km is defined as the average number of failures in a line or cable per 100 circuit km per year.

(this parameter is determined separately for 110 kV, 220 kV and 380 kV lines/cables)


Line Cable Failure rates are determined by using the following formula:

Voltage

VoltageVoltage LengthCircuitTotal

failurescablelineofNumberratefailureCableLine

___/__

__/ =

(for definition of Total_Circuit_Length see section 2.1.3)

Target

Although failures in lines and cables are not completely be prevented, KOSTT should aim for the lowest possible number of faults. A realistic target can only be given if some historical figures are available.


2.7.2 Average repair time of Line/Cable failures

N° IT2 Average repair time of Line/Cable failures (hours)

Definition

Average repair time of Line/Cable failures is defined as the average duration in hours of repairing lines and cables in case of failures in a line or cable.



Average repair time of Line/Cable failures is determined by using the following formula:

Voltage

VoltageatfailurescablelineallVoltage failuresofNumber

nrestoratioofDurationtimerepairAverage

__

____ _____

∑=

(repair time is the duration in hours between the failure and taking the line/cable in operation again)

Target

Although failures in lines and cables are not completely be prevented, KOSTT should aim for a fast repair. A realistic target can only be given if some historical figures are available.

2.7.3 Average Outage time due to Line/Cable maintenance

N° IT3 Average Outage time due to Line/Cable maintenance (minutes)

Definition

Average Outage time due to Line/Cable maintenance is defined as part of Average Interruption Time (see section 2.3.1), caused by planned maintenance on Lines and Cables.



EnergydTransmittemainlinetodueSuppliedNotEnergymainLinetodueTimeOutageAverage

_______.60.8760______ =



∑=

⋅=outagesalli


____

Target

Outages due to maintenance should be minimised. A realistic target can only be given if some historical figures are available.

2.7.4 Transformer Failure rate per 100 Transformers

N° IT4 Transformer Failure rate per 100 Transformers

Definition

Transformer Failure is defined as the average number of failures per 100 transformers per year.

(this parameter is determined separately for 380-220/110 kV transformers, and 220-110 kV transformers)


Transformer Failure rates are determined by using the following formula:

Voltage

VoltageVoltage sTransfomerofNumberTotal

failuresrtransformeofNumberratefailurerTransforme

______100

__⋅

=

Target

Although failures in Transformers are not completely be prevented, KOSTT should aim for the lowest possible number of faults. A realistic target can only be given if some historical figures are available.

2.7.5 Average repair time of Transformer failures

N° IT5 Average repair time of Transformer failures (hours)

Definition


Average repair time of Transformer failures is defined as the average duration in hours of repairing Transformers in case of failures in a line or cable.



Average repair time of Transformer failures is determined by using the following formula:

Voltage



__

____ _____

∑=

(repair time is the duration in hours between the failure and taking the Transformer in operation again)

Target

Although failures in Transformers can always happen, KOSTT should aim for a fast repair. A realistic target can only be given if some historical figures are available.

2.7.6 Average Outage time due to Transformer maintenance

N° IT6 Average Outage time due to Transformer maintenance (minutes)

Definition

Average Outage time due to Transformer maintenance is defined as part of Average Interruption Time (see section 2.3.1), caused by planned maintenance on Transformers.



EnergydTransmittemainTrafotodueSuppliedNotEnergymainTrafotodueTimeOutageAverage

_______.60.8760______ =


∑=

⋅=outagesalli


____


Target


2.7.7 Switchgear Failure rate per 100 bays

N° IT7 Switchgear Failure rate per 100 bays

Definition

Switchgear Failure is defined as the average number of Switchgear failures per 100 Bays per year.

(this parameter is determined separately for 380, 220 and 110 kV Switchgear)


Switchgear Failure rates are determined by using the following formula:

Voltage

VoltageVoltage BaysofNumberTotal

failuresswitchgearofNumberratefailureSwitchgear

______100

__⋅

=

Target

Although failures in Switchgear are not completely be prevented, KOSTT should aim for the lowest possible number of faults. A realistic target can only be given if some historical figures are available.

2.7.8 Average repair time of Switchgear failures

N° IT8 Average repair time of Switchgear failures (hours)

Definition

Average repair time of Switchgear failures is defined as the average duration in hours of repairing Switchgear in case of failures in a line or cable.




Average repair time of Switchgear failures is determined by using the following formula:

Voltage



__

____ _____

∑=

(repair time is the duration in hours between the failure and taking the Switchgear in operation again)

Target

Although failures in Switchgear can always happen, KOSTT should aim for a fast repair. A realistic target can only be given if some historical figures are available.

2.7.9 Average Outage time due to Switchgear maintenance

N° IT9 Average Outage time due to Switchgear maintenance (minutes)

Definition

Average Outage time due to Switchgear maintenance is defined as part of Average Interruption Time (see section 2.3.1), caused by planned maintenance on Switchgear.



EnergydTransmittemainSwitchgeartodueSuppliedNotEnergymainSwitchgeartodueTimeOutageAverage

_______.60.8760______ =


∑=

⋅=outagesalli


____

Target



2.7.10 Control/Protection Failure rate per 100 bays

N° IT10 Control/Protection Failure rate per 100 bays

Definition

Control/Protection Failure is defined as the average number of Control/Protection failures per 100 Bays per year.

(this parameter is determined separately for 380, 220 and 110 kV Control/Protection, for Transformers Control/protection the high Voltage is taken as a reference)


Control/Protection Failure rates are determined by using the following formula:

Voltage

VoltageVoltage BaysofNumberTotal

failuresprotectionControlofNumberratefailureprotectionControl

____/__100

__/⋅

=

Target

Although failures in Control/Protection are not completely be prevented, KOSTT should aim for the lowest possible number of faults. A realistic target can only be given if some historical figures are available.

2.7.11 Average repair time of Control/Protection failures

N° IT11 Average repair time of Control/Protection failures (hours)

Definition

Average repair time of Control/Protection failures is defined as the average duration in hours of repairing Control/Protection in case of failures in a line or cable.

(this parameter is determined separately for 380, 220 and 110 kV Control/Protection, for Transformers Control/protection the high Voltage is taken as a reference)


Average repair time of Control/Protection failures is determined by using the following formula:


Voltage



__

____ _____

∑=

(repair time is the duration in hours between the failure and taking the Control/Protection in operation again)

Target

Although failures in Control/Protection can always happen, KOSTT should aim for a fast repair. A realistic target can only be given if some historical figures are available.

2.7.12 Average Outage time due to Control/Protection maintenance

N° IT12 Average Outage time due to Control/Protection maintenance (minutes)

Definition

Average Outage time due to Control/Protection maintenance is defined as part of Average Interruption Time (see section 2.3.1), caused by planned maintenance on Control/Protection.

(this parameter is determined separately for 380, 220 and 110 kV Control/Protection)


EnergydTransmittemainprotContrtodueSuppliedNotEnergymainprotContrtodueTimeOutageAverage

__/_____.60.8760_/_____ =


∑=

⋅=outagesalli


____

Target


(End of Document)


technical performance indicators - kostt

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