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ANNUAL POWER QUALITY PERFORMANCE REPORTING SPECIFICATION

FINAL

July 2003

The South African National Electricity Regulator (NER), under the guidance of its Power Quality Advisory Committee, has developed a framework for the management of power quality in South Africa. This has been published as a directive of the NER, and addresses the requirements of both licensees and their customers in dealing with power quality concerns. Annual reporting by licensees forms a key component of this power quality management framework. In terms of the Directive, the NER will publish an annual report detailing: •

•

•

Annual power quality statistics (including comparative and historical trends on power quality performance).

Complaints statistics (non-conformance reports as well as disputes that have reached the level of the NER in the context of the Power Quality Management System implemented by licensees).

Progress of the licensees in implementing their Power Quality Management Systems.

This specification defines the manner in which licensees report their performance statistics, the monitoring requirements for such reporting, and the publication of the results of this by the NER. An example format for the NER's annual review report is provided as an annex for illustrative purposes. The scope of this specification includes both Eskom Transmission (and the future independent Transmission Agent), and Distribution licensees (and future RED's). Licensees are required to implement the requirements of this document. For queries on the contents of this document please contact Tshilidzi Thenga at: Email: [email protected]. Tel. no.: (012) 401 4600 Cell no.: 082-414-8368 Copies of the Power Quality Directive and Power Quality management System Specification are available on the NER’s web page www.ner.org.za.

Annual Power Quality Performance Reporting Specification

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1. GENERAL 1.1. Scope In terms of the NER Directive on power quality, the NER requires a minimum level of annual reporting by Distribution licensees and by the Transmission service provider. The scope of such reporting is: • • • • • •

• • • • •

•

Voltage quality (voltage magnitude, harmonics, unbalance, flicker) Voltage disturbances (dips) Interruption performance Power quality complaints statistics (see note 1 below) Instrument statistics and instrument availability data Progress in terms of the Power Quality management System implementation plans submitted to the NER

Note 1: Complaints statistics related to Non-Conformance Reports which may arise due to any power quality problem (e.g. dips, interruptions, harmonics, voltage magnitude, unbalance etc). The process of generating NCR's is defined generally in terms of the NER Directive, and specifically in terms of the individual licensee Power Quality Management System Specifications submitted to the NER in July/August 2003. 1.2. Purpose The agreed purpose of such annual reporting is to:

Establish benchmark statistics (historical and comparative information) Evaluate long-term trends in the industry (see note 1 below) Identify specific priorities that need to be addressed from a regulatory point of view Identify and evaluate the viability of specific potential incentive measures To ensure that data such as interruption and dip performance data, which cannot be collected at short notice, is available for decision purposes Demonstrate to the various stakeholders (government, customers, licensees, and investors) that aspects pertaining to Power Quality are being managed appropriately.

The NER will publish an annual review of the submission results. Note 1: Changes in performance trends with time are affected by many parameters (e.g. seasonal changes, network changes, maintenance practices etc). The underlying nature of these changes needs to be analysed to understand these trends. The aim of technical reporting is to provide a consistent and transparent foundation for such an analysis. 1.3. Licensee Annual Reporting Requirements The first submissions are required in 2004. Until the establishment of RED's, it is not feasible to require all licensees to provide detailed reports of statistically monitored technical performance data. For this reason, only licensees with an annual maximum notified demand in excess of 100 MVA (arithmetic sum of notified demand at all supply points) are required to provide such data in 2004. All licensees are required to provide statistics on complaints data and progress in the implementation of the Power Quality Management System specifications submitted to the NER in July/August 2003. This data will form one of the considerations for extending measurements to additional licensees.


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In order to provide a more reflective analysis in the pilot implementation of this specification, particularly in the context of future RED's, Eskom Distribution is required to report on a regional basis. Other licensees will not be required to provide a more detailed breakdown. 1.4. Reporting Principles Actual performance is reported on an annual basis. The intent is, where possible, for appropriate international measures to be used in the reporting process so that more meaningful international comparisons can be undertaken. Where it is recognised that the systems of some licensees do not presently support the information required by such measures, interim measures are defined. NRS 048-3:2002 has achieved common agreement on reporting requirements by licensees, and forms the foundation for this reporting specification. Changes made in this NER reporting specification reflect specific new requirements of the NER Directive, which was adopted by the NER after the consultation process on NRS 048-3 was completed. Some of the tables in NRS 048-3 required for reporting are included in Annex A of this specification to highlight interpretation issues and communicate modified requirements. In order to develop a sound perspective for the first annual performance review report, 5-year retrospective performance from 1999 will be required for technical performance data (i.e. data reflecting the performance for the calendar years 1999, 2000, 2001, 2002, and 2003). Both permanent and sampled sites are addressed in this reporting specification in the case of distribution licensees. 1.5. Statistical and Sample Reporting: Data Validation Reported information for permanent sites may exclude measured data in the following cases: •

•

•

Where the measurement did not reflect actual quality levels at the measured supply point (e.g. if the instrument was faulty or the event was due to the instrument being temporarily disconnected). Where data has been flagged according to the flagging rules in IEC 61000-4-30 (Note: where flagging is done outside of the instrument this should be subject to quality audits from time to time). Force majeure events as defined in NRS 048-2:2003. Such exclusions shall be specifically documented in the return.

With the exception of specific exclusions based on the above, "valid data" shall include all events measured. Assessment methods applied to statistically monitored data are defined in NRS 048-2:2003. These shall be used in the reporting process. Any deviations from this shall be specifically highlighted in the return.


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2. TRANSMISSION REPORTING 2.1. Overview The transmission system plays an important role in national and regional power quality performance, particularly in the case of HV customers. Trend reporting and comparative reporting of the performance to the various RED's is therefore important as a foundation for the new power quality management framework. For power quality reporting purposes, delivery point indices are used for voltage quality, dips, and interruption reporting. 2.2. Requirements In terms of the NER Power Quality Directive, the following power quality monitoring requirements apply to the transmission licensee: 2.2.1 Statistical monitoring

All permanent transmission supply points shall be monitored on a continuous basis (see notes 1 and 2 below). A supply point is defined as the geographical point at which the distribution licensee or direct customer takes power, or where more practical, the closest point agreed between the transmission licensee and the affected distribution licensee or direct customer(s). In general this will be a transmission substation. Where multiple delivery points are associated with a transmission supply point, at least one delivery point shall be monitored (see notes 3 and 4 below). Where agreement cannot be reached between the transmission licensee and the distribution licensee, the NER will rule on the point to be monitored. In some cases the transmission licensee and the distribution licensee may wish to share a power quality monitoring device. In this case, the transmission licensee shall maintain all its obligations with regard to data reporting and data quality.

2.2.2. Sample monitoring

Some sites specified by the NER may require periodic sample measurements for a minimum period (e.g. of one week in the case of voltage quality parameters). This is typically foreseen where concessions have been made by the NER to allow relaxed power quality levels, and where permanent monitoring is not in place (e.g. for parameters such as flicker that do not require permanent monitoring, or sites that have been agreed with the NER not to be permanently monitored). Sample recording may also in future be required for transmission delivery points that are not permanently monitored.

2.2.2 Complaints monitoring

Some sites specified by the NER may require measurements for a minimum period of one week in order to resolve complaints or disputes related to voltage waveform problems.

Note 1. Deviations from this requirement may be requested from the NER on a site-for-site basis. Note 2. Where supply points are temporarily in place (i.e. less than 6 months), monitoring is not required. Note 3. Because most Transmission dip reporting is related to the supply network, where multiple busbars (or voltage levels) exist in a substation, monitoring of one such busbar would be sufficient to define Transmission dip performance. Note 4. The choice of the measurement point should be based on maximising the value added to the power quality management process as defined in the NER Directive. As a guideline for multiple delivery points and a single monitor at the transmission supply point, the delivery point selected for monitoring should be the one most likely to present problems (e.g. where capacitors are connected), or where the majority of sensitive customers are supplied.


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2.3. Data (instrumentation) availability for statistical reporting purposes 2.3.1. Total data availability

The total data availability for all permanently monitored sites for statistical reporting shall be better than 99% (this availability is defined as the total number of hours that all permanent sites were monitored according to the appropriate standards, divided by the total number of hours for the year for all these sites).

2.3.2. Individual site data availability

In addition to total data availability, where data communications is available no individual transmission supply point shall remain unmonitored according to the above requirements for more than 1 month continuously, and 6 weeks in the case of sites with no data communications facility. Sites where this requirement is not met should be recorded in the annual submission to the NER.

2.4. Reported Data: Annual Statistical Reporting 2.4.1. Voltage Quality Statistics

The following voltage quality statistics shall be reported by the licensee: • • •

• • • • • • • • • •

Voltage harmonics (format according to NRS 048-3:2002 Table 9) Voltage unbalance (format according to NRS 048-3:2002 Table 10) Voltage magnitude (format according to NRS 048-3:2002 Table 12)

Voltage quality data is reported as the number of exceedance periods per site over the reporting period. An exceedance period shall be considered as having occurred when the assessed 95% weekly value exceeds the appropriate requirements in NRS 048-2:2003 (note 1). A weekly assessed value shall be determined on a daily basis for the previous 7 days, starting with the first 10 minute value after 00h00 on the first day. For clarity, the first weekly value for the reporting year shall be calculated on 1 January of the current reporting year.

Note 1. In the case of voltage magnitude, the number of exceedance periods of the magnitude limit value shall also be reported.

2.4.2. Voltage Dip Statistics

Voltage dip statistics (number of measured events) for X1, X2, S, T, Z1 and Z2 dips (defined in NRS 048-2:2003) shall be reported per site on an annual basis (format according to table 11 of NRS 048-3:2002). Two statistics shall be reported against each of these dip types, i.e. the total number of events, and transmission-caused events only.

2.4.3. Interruption Statistics

The following delivery point interruption statistics shall be reported by the licensee: SAIFI-MI: momentary interruptions - excluding MV tertiary supplies SAIFI-SI: sustained interruptions - excluding MV tertiary supplies SAIDI - sustained interruptions excluding MV tertiary supplies SAIRI - sustained interruptions excluding MV tertiary supplies Total system minutes for events of degree severity < 1 Number of system minute events of degrees 0, 1, 2, and 3 (bulk supply system) Number of system minutes of degrees 0, 1, 2, and 3 (local system events) Generation / transmission initiated load shed events A description of individual events that resulted in a system minute count of > 1. The number of transmission supply points and delivery points


5

The definitions applied for an interruption, a momentary interruption, and a load shed event shall be those documented in NRS 048-2:2003. The following definitions apply for national statistics:

pointsreception anddelivery ion transmissofnumber Totalonsinterruptipoint eception delivery/r sustained ofnumber Total SI-SAIFI =

pointsreception anddelivery ion transmissofnumber Totalonsinterruptipoint eception delivery/rmomentary ofnumber Total MI-SAIFI =

pointsreception anddelivery ion transmissofnumber Totaldurationson interruptipoint eception delivery/r sustained all of Sum SAIDI =

onsinterruptipoint eception delivery/r sustained ofnumber Totaldurationson interruptipoint eception delivery/r sustained all of Sum SAIRI =

The above indices shall be reported with and without the inclusion of major events (defined as bulk system events of 1 minute and more - see table below). On the establishment of RED's, the performance applicable to the delivery points to each RED shall be reported separately for the above indices. The following definition of system minutes shall be applied:

period for the demandpeak annual System 60(MWh)x Energy d UnsupplieEstimated Total Minute System =

The degree of severity for individual measures is defined in the table below.

Table 2.1- Bulk Electricity System (BES) and local severity measures.

Degree Description BES Local Severity (SM) (MW.min) 0 - unreliability condition normally considered < 1 < 1000 acceptable 1 - significant impact on one ore more 1 - 9 1000 - 9999 customers but not considered serious - impact less that 10 times that acceptable 2 - serious impact on customers 10-99 10000 - 99999 - impact considered 10 to 100 times that acceptable 3 - a very serious impact on customers >= 100 >= 100000 - impact considered more than 100 times that acceptable

2.4.4 Complaints: NCR and Dispute Statistics

The licensee shall provide annual statistics on NCR's and disputes according to Table B.2. in Annex B.

2.4.5 Quality Management System Implementation

The licensee shall provide feedback on the milestones identified in the submission to the NER of July/August 2003, and any additional requirements communicated by the NER in response to this submission.


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2.5. Interpretation In order to facilitate the review process by the NER, the licensee shall provide information on:

Any changes in monitoring or reporting philosophy (e.g. interpretation of indices). • • •

•

Any specific information excluded from the indices reported, with reasons for this Known reasons for specific performance degradation / improvement against any of the reported indices. Interventions identified or implemented to address specific performance issues.


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3. DISTRIBUTION LICENSEE REPORTING 3.1. Overview It is not appropriate from a cost, technical, and logistical point of view to specify a power quality monitoring requirement that achieves full statistical accuracy in reporting distribution licensee power quality performance (disturbance and voltage quality parameters). The random placement required by such a statistical sample may also not provide optimal value in terms of managing the levels of quality on the network. The selection of monitoring sites by distribution licensees is therefore based not on statistical criteria, but on the selection by the licensee of sites to be monitored that best achieve the goal of managing quality levels. Comparative reporting of the results of such statistical monitoring is therefore not appropriate. Trend reporting is more appropriate (see note 1 below). Note 1: Changes in performance trends with time are affected by many parameters (e.g. seasonal changes, network changes, maintenance practices etc). The underlying nature of these changes needs to be analysed to understand these trends. The aim of technical reporting is to provide a consistent and transparent foundation for such an analysis. 3.2. Statistical Reporting In terms of the NER Power Quality Directive, the following monitoring requirements apply to distribution licensees: 3.2.1. Statistical monitoring

The permanent instrumentation requirements for statistical monitoring are defined in NRS 048-3:2003. In some cases the transmission licensee and the distribution licensee may choose to share a common power quality monitoring device at an interface point. In this case, the distribution licensee shall maintain all its obligations with regard to data reporting and data quality as stipulated by the directive. The distribution licensee shall select the most appropriate set of sites to meet the statistical monitoring requirements. The selection of these sites shall be based on providing the best basis for managing power quality performance in terms of the power quality management framework in the NER Directive. It is accepted that the sites chosen may reflect a bias towards poorer performing sites. This will be highlighted in the NER's annual performance review.

3.2.2. Sample monitoring

Some sites specified by the NER will require periodic sample measurements for a minimum period (e.g. of one week in the case of voltage quality parameters). This is typically foreseen where concessions have been made by the NER to allow relaxed power quality levels, and where permanent monitoring is not in place (e.g. for parameters such as flicker that do not require permanent monitoring, and sites that have been agreed with the NER not to be permanently monitored).

3.2.3. Complaints monitoring

Some sites will require measurements for a period of at least one week in order to demonstrate compliance where a complaint has been lodged by a customer. Such monitoring will form the basis of the "validated complaints" statistics defined below.


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3.3. Instrument availability for statistical reporting purposes 2.3.3. Total data availability

The total data availability for all permanently monitored sites for statistical reporting shall be better than 95% (this availability is defined as the total number of hours that all permanent sites were monitored according to the appropriate standards, divided by the total number of hours for the year for all monitored sites).

2.3.4. Individual site data availability

In addition to total data availability, where data communications is available no individual transmission supply point shall remain unmonitored according to the above requirements for more than 1 month continuously, and 6 weeks in the case of sites with no data communications facility. Sites where this requirement is not met should be recorded in the annual submission to the NER.

2.4. Reported Data: Annual Statistical Reporting 2.4.1. Voltage Quality Statistics: Permanently Monitored Sites

The following voltage quality statistics shall be reported by the licensee: • • •

Voltage harmonics (format according to NRS 048-3:2002 Table 9) Voltage unbalance (format according to NRS 048-3:2002 Table 10) Voltage magnitude (format according to NRS 048-3:2002 Table 12)

Voltage quality data is reported as the number of exceedance periods per site over the reporting period. An exceedance period shall be considered as having occurred when the assessed 95% weekly value exceeds the appropriate requirements in NRS 048-2:2003 (note 1). A weekly assessed value shall be determined on a daily basis for the previous 7 days, starting with the first 10 minute value after 00h00 on the first day. For clarity, the first weekly value for the reporting year shall be calculated on 1 January of the current reporting year.

Note 1. In the case of voltage magnitude, the number of exceedance periods of the magnitude limit value shall also be reported.

2.4.2. Voltage Quality Statistics: Validated Customer Complaints

The licensee shall provide annual statistics on the number of validated customer complaints for the reporting year according to Table B.1. in Annex B. A validated customer complaint is defined as a complaint that is found upon investigation to be accompanied by an exceedance of the voltage waveform quality requirements in NRS-048-2 (i.e. the compatibility levels or limits defined for voltage magnitude, harmonics, unbalance, flicker). Such an investigation may include a known network condition giving rise to such an event, measurement data from a permanently installed instrument (note 1), or measurements conducted for the purpose of resolving the complaint at or close to the supply point for at least one week (note 2). Note 1. Should a complaint be verified by measured data from a site not at the customer supply point, a measurement at the supply point is not required. The complaint is then counted as a verified complaint. Note 2. Should a complaint be verified by a measurement of less than one week, the full week measurement is not required. The complaint is then counted as a verified complaint.


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2.4.3. Voltage Dip Statistics

Voltage dip statistics (number of measured events) for X1, X2, S, T, Z1 and Z2 dips (defined in NRS 048-2:2003) shall be reported per site on an annual basis (format according to table 11 of NRS 048-3:2002). Two statistics shall be reported against each of these dip types, i.e. the total number of events, and transmission-caused events only.

2.4.4. Interruption Statistics

Licensees shall report interruption performance separately for HV and MV systems using the following indices: • • • •

SAIFI SAIDI CAIDI Forced Interruption Index / Supply Loss Index (NRS 048-3:2003)

Some licensees do not use SAIFI, SAIDI, and CAIDI internally and are at this stage unable to make reasonable estimates of the number of customers affected by an interruption. These licensees may provide only the annual interruption statistics according to tables 14 - 17 in NRS 048-3:2002 up to the year 2005. The following definitions apply (see note 1):

ServedCustomersofNumber TotalEventon InterruptiEach for Customers dInterrupte ofNumber

SAIFI ∑=

Served Customers ofNumber TotalDurationson InterruptiCustomer

SAIDI ∑=

∑∑=

Eventon InterruptiEach for Customers dInterrupte ofNumber Durationson InterruptiCustomer

CAIDI

Note that:

SAIFISAIDI CAIDI=

Note 1. IEEE-1366 standard on distribution reliability is to be completed in 2003. This shall form the guideline for the calculation of the above interruption indices (e.g. the calculation of SAIDI and CAIDI in the case of stepped restoration). Use of this standard will ensure international compatibility of reported interruption performance. The above indices shall be reported with and without the inclusion of major incidents. The statistical method for identifying if an indicnet is a "major incident" or not, shall be the method applied in IEEE-1366.

2.5.5. Complaints: NCR and Dispute Statistics

The licensee shall provide annual statistics on NCR's and disputes according to Table B.2. in Annex B.


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2.5.6. Quality Management System Implementation

The licensee shall provide feedback on the milestones identified in the submission to the NER of July/August 2003, and any additional requirements communicated by the NER in response to this submission.

2.5. Interpretation In order to facilitate the review process by the NER, the licensee shall provide information on:

Any changes in monitoring or reporting philosophy (e.g. interpretation of indices). • • •

•

Any specific information excluded from the indices reported, with reasons for this Known reasons for specific performance degradation / improvement against any of the reported indices. Interventions identified or implemented to address specific performance issues.


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4. NER ANNUAL POWER QUALITY PERFORMANCE REVIEW 4.1. Overview The annual performance review published by the NER will, where appropriate: •

• • • •

• • • • •

• • •

Report comparative and trended information for voltage waveform quality, voltage dips, interruptions, and complaints statistics. Provide a fair and informed assessment of performance trends in the industry Reflect proposed interventions by licensees, where appropriate. Report on levels of compliance to the NER Directive by licensees. Highlight potential issues that can be addressed by specific regulatory interventions of the NER.

4.2. Process and Timetable The following process and timetable will be implemented in publishing the report:

28 February Receipt of licensee returns for the previous calendar year 31 March Compilation of a draft performance report by the NER 30 April Receipt of licensee comments on the draft report 31 May Workshop the report and comments with the Advisory Committee 30 June Publish Annual Power Quality Performance Review Report

4.3. Submission Process To facilitate the submission process, the NER will:

Provide the copies of submission formats. Institute a simple help system for dealing with queries on the reporting requirements Track and manage overdue submissions.

4.4. Accuracy of Reported Data The NER may elect to undertake audits on annual submissions where appropriate during the period end February to May. The annual statistics shall be signed by the CEO (or equivalent) as being true and correct to his/her best knowledge. 4.5. Auditing In terms of the Power Quality Directive the NER may commission periodic audits of the quality assurance systems in place in the various licensees. This will be in accordance to a defined audit plan. An important component of this audit is an assessment of the practices used by licensees in recording and reporting statistics in terms of this specification, as it is important that this is done accurately, consistently and uniformly.


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ANNEX A: LICENSEE REPORTING (ADJUSTMENTS TO NRS 048-3:2003) A.1. Declaration of sites The table below lists the NRS 048-3:2002 instrument requirements for a distribution licensee (note that according to NRS 048-3:2002 and this specification, a transmission licensee is required to monitor all sites).

Table A.1. Declaration of sites: Transmission Transmission Sites Total number of sites______ Sites permanently monitored No. Substation Busbar Voltage (kV) Customer/RED History (yrs)

(Note 1)

Table A.2. Declaration of sites: Distribution Distribution Sites Total number of sites______ Sites permanently monitored No. Substation Busbar Voltage (kV) Site category History (yrs)

(Note 1)

Note 1: Installed for more than 6 months in a year


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A.2. Reporting Tables According to NRS 048-3:2003

Specific NRS 048-3:2003 reporting tables referred to in this document, are included for below clarity. Specific changes introduced since the publication of NRS 048-3:2002, as well as interpretation issues are addressed as notes accompanying the tables .

Note 1: With the introduction of weekly reporting in NRS 048-2:2003, Column 6 shall be interpreted as the weekly 95% value (i.e. the 7 days up to the date that the value is logged) being exceeded. Note that a new weekly value is calculated at the end of every day. Note 2: In the case of MV systems, the comparison in column 6 shall be made with the compatibility level. Note 3: For reporting purposes, a minimum requirement is that harmonic voltage orders 3,5,7,11, and 13 shall be compared to the planning/compatibility levels (column 5). Where more than one is exceeded in the reporting year, each of these shall be listed (e.g. THD, 5th and 11th). Note 4: The instrument location shall be the substation name, and busbar (where multiple busbars exist).

Note 1: With the introduction of weekly reporting in NRS 048-2:2003, Column 5 shall be interpreted as the weekly 95% value (i.e. the 7 days up to the date that the value is logged) being exceeded. The weekly value is calculated on a daily basis. Note 2: The instrument location shall be the substation name, and busbar (where multiple busbars exist).

Note 1: With the revision of NRS 048-2 (2003), the above table shall reflect all the new dip categories (X1, X2, S, T, Z1, and Z2), but exclude Y-type dips.


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Note 2: The nominal voltage in column 4 shall refer t the voltage at which the instrument is connected.


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ANNEX B: COMPLAINTS REPORTING (NEW REQUIREMENTS) B.1. Validated Voltage Quality Complaints Table B.1. Validated customer complaints (Distribution Licensees) Voltage Waveform Quality: Validated Retail Customer Complaints

Urban Rural Customer Category LV MV LV MV

HV

Residential Agricultural Commercial Industrial Bulk

B.2. Complaints: Non-conformance Reports (NCR's) Table B.2. Submission of complaints statistics (NCR's and formal Disputes lodged with the NER) Complaint statistics as at 31 December (NCR's and formal Disputes) Customer Complaint Reference No.

Customer Name

Customer Category

Code

Complaint Category Code(s)

NCR Date

Initiated

Dispute Date

Initiated*

Date

Resolved*

* Note: Where a date is not applicable, please type "X" Customer Category Code: (e.g. R01)

Complaint Category Code: (e.g. 03)

R Rural U Urban N Not defined 01 Industrial 02 Commercial 03 Agricultural 04 Residential 05 Re-distributor 06 Various (group action) 07 Other

01 Interruptions 02 Voltage dips 03 Voltage magnitude 04 Voltage unbalance 05 Voltage harmonics 06 Voltage flicker 07 Other


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ANNEX C: EXAMPLE OF ANNUAL PERFORMANCE REVIEW REPORT (The format below illustrates the processing of the data received by the NER and the manner in which this will be communicated in the annual report. It is not intended to be reflective of

actual performance - all values and statistics are illustrative). Statistical Performance Reporting: Transmission Background The quality delivered by the Transmission Grid provides a foundation for the quality delivered by regional distributors. The Transmission Operator provides annual reports on performance of the national grid with regard to voltage waveform quality (voltage magnitude, harmonics, and unbalance), voltage dips, and interruption performance. Sites Monitored Statistical reporting is provided for …… monitoring sites out of a total of ….. Transmission delivery points. The delivery points not reported on are not monitored for the following reasons: ,,,,,,,,,,,,,,, The total availability of the power quality monitors was …..% for the year ending 31 December. This (exceeds/is below) the target of 99%. Waveform Quality Voltage waveform quality is managed by setting limits on the deviation of the voltage from the ideal 50Hz sinusoidal waveform. For transmission delivery points, these limits are based on planning levels in NRS-048-2 or by agreement with customer. Waveform quality is affected by both the operation of the transmission grid and by the combined effect of customers connected to the grid. It is therefore difficult to guarantee that a specific site will not exceed the limits in any given year. From a regulatory point of view, a target for all sites is that no more than 5% of sites should exceed the agreed levels and limits. What is important is that a specific site does not remain continuously outside of the limits (i.e. that action is taken by the system operator to address problems). The sites that exceeded the agreed levels are reported annually.

Transmission Voltage Magnitude Performance

0%

2%

4%

6%

8%

10%

12%

14%

1998 1999 2000 2001 2002 2003

Year

Perc

enta

ge o

f Site

s

Exceeding Agreed LevelsExceeding LimitsTarget

Figure 3 Voltage magnitude performance and trend (percentage of sites exceeded).


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Figure 1 shows the annual number of sites exceeding the voltage magnitude limits. Figure 2 shows the annual number of sites exceeding the voltage magnitude limits for 2 years consecutive years (target 2%) and 3 consecutive years respectively (target 0%). Voltage Dip Performance: Transmission Caused Dips NRS-048-2:2003 has defined characterisatic dip performance in terms of dip windows and statistics based on the 95 percentile of sites and 50 percentile of sites. The dip performance at Transmission supply points is shown below for the reporting year and the average performance since 1998. This performance reflects dips caused by events on the transmission network only. The site sample is ……. HV sites and ….. EHV sites.

Table 1 Number of voltage dips per year for each category of dip window (95% of sites)

Number of voltage dips per year Network voltage range Dip window category

(nominal voltages) X1 X2 T S Z1 Z2 > 44 kV to ≤ 132 kV 35

24 35 24

25 24

40 24

40 24

10 24

220 kV to ≤ 765 kV 30 24

30 24

20 24

20 24

10 24

5 24



(nominal voltages) X1 X2 T S Z1 Z2 > 44 kV to ≤ 132 kV 13

24 10 24

5 24

7 24

4 24

2 24

220 kV to ≤ 765 kV 8 24

9 24

3 24

2 24

1 24

1 24

Voltage dip performance is strongly influenced by annual weather patterns, and for this reason a year-on-year comparison of dip performance is not a good indication of actual performance trends (particularly in the case of a single site). The figure below shows the trend in the 3-year average for the various dip categories. The average represents the average number of dips seen by all sites over a three year period ending at the year indicated.

HV Dip Performance Trend (Average over a 3-year window)

0

5

10

15

20

25

30

35

40

45

50

2000 2001 2002 2003

Reporting Year

Num

ber o

f dip

s X1X2STZ1Z2

Figure 2 National dip performance trend: transmission-caused dips only.


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Comparative Dip Performance

0

5

10

15

20

25

30

35

40

45

50

RED

1 X

1

RED

2 X

1

RED

3 X

1

RED

4 x

1

RED

5 X

1

RED

6 X

1

RED

1 X

2

RED

2 X

2

RED

3 X

2

RED

4 X

2

RED

5 X

2

RED

6 X

2

RED

1 T

RED

2 T

RED

3 T

RED

4 T

RED

5 T

RED

6 T

RED

1 S

RED

2 S

RED

3 S

RED

4 S

RED

5 S

RED

6 S

RED

1 Z

1

RED

2 Z

1

RED

3 Z

1

RED

4 Z

1

RED

5 Z

1

RED

6 Z

1

RED

1 Z

2

RED

2 Z

2

RED

3 Z

2

RED

4 Z

2

RED

5 Z

2

RED

6 Z

2

Num

ber o

f Dip

s

Figure 3 Comparative dip statistics (range per dip category per RED): transmission-caused

dips only.

Population0 - 5000050000 - 100000100000 - 400000400000 - 10000001000000 - 2800000

Provincial Boundaries

N

200 0 200 400 Kilometers

Figure 4 National dip performance statistics at Transmission supply points

(including/excluding dips caused by distribution licensees).

Transmission Interruptions (Average number of events per annum) The average number of interruptions seen by each of the Transmission delivery and reception (generation) points is shown below for the total Transmission system.


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Transmission SAIFI (National)

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

1998 1999 2000 2001 2002 2003

Year

SAIF

I

Figure 5 SAIFI (System Average Interruption Frequency Index):

National System (all supply and reception points). The average number of interruptions seen by each of the Transmission delivery and reception (generation) points is shown below for each of the RED's and for generation connected to the Transmission system.

Transmission SAIFI (Comparative)

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

RED 1 RED 2 RED 3 RED 4 RED 5 RED 6 GEN

SAIF

I

Figure 6 SAIFI (System Average Interruption Frequency Index):

Supply to Regional Distributors .

Transmission Interruptions (Average duration per supply point) The average number of interruptions seen by each of the Transmission delivery and reception (generation) points is shown below for the total Transmission system. (SAIDI as for SAIFI). Transmission Interruptions (Average restoration time per interruption) The average number of interruptions seen by each of the Transmission delivery and reception (generation) points is shown below for the total Transmission system. (SAIRI as for SAIFI). Transmission Interruptions (Severity: small interruptions) (SM<1 as for SAIFI).


20

Transmission Interruptions (Severity: major interruptions) Major system interruptions are categorised according to bulk electricity system (BES) events (e.g. cascading faults affecting a loarge area) and localised events (e.g. failure of a local transformer).

Table 3- Bulk Electricity System (BES) and local severity measures.

Degree Description BES Local Severity (SM) (MW.min) 0 - unreliability condition normally considered < 1 < 1000 acceptable 1 - significant impact on one ore more 1 - 9 1000 - 9999 customers but not considered serious - impact less that 10 times that acceptable 2 - serious impact on customers 10-99 10000 - 99999 - impact considered 10 to 100 times that acceptable 3 - a very serious impact on customers >= 100 >= 100000 - impact considered more than 100 times that acceptable

Table 4: Bulk System Interruptions Table 5: Local Interruptions (>1000MW.min)

Degree 1

Degree 2

Degree 3

Degree 1

Degree 2

Degree 3

1998 ▼ 1998 ▼ 1999 1999 2000 ▼▼ 2000 ▼▼ 2001 ▼ ▼▼ 2001 ▼ ▼▼ 2002 ▼ 2002 ▼ 2003 ▼ 2003 ▼

Statistical Performance Reporting: Distribution Licensees Background The permanently-installed distribution sites are not a statistically reflective sample. Distribution licensees are encouraged to place power quality instruments at locations in the network that meet optimal power quality management needs. This may result in a tendency for "bad", rather than good sites to be selected for permanent monitoring purposes, or for sites with sensitive customers to be prioritised. The results reported in this chapter therefore focus on performance trends.


21

Sites Monitored The table below lists the number of sites permanently monitored by each of the licensees. Table 6. HV network instrument statistics.

HV RED Magnitude Unbalance Harmonics Dips Availibility

1 92% 2 95% 3 97% 4 99% 5 96% 6 92%

Table 7. MV network instrument statistics.

MV RED Magnitude Unbalance Harmonics Dips Availibility

1 92% 2 95% 3 97% 4 99% 5 96% 6 92%

The minimum requirement for instrument availability is 95%. Voltage Waveform Quality Voltage waveform quality is managed by setting limits on the deviation of the voltage from the ideal 50Hz sinusoidal waveform. For HV points, these limits are based on planning levels in NRS-048-2. For MV and LV supply points, these are based on the relevant compatibility levels and limits specified in NRS-048-2.. The lack of a statistically representative (random) sample of measurement points makes the accurate reporting of voltage waveform quality performance difficult for distribution licensees. In order to assess the manner by which utilities are managing voltage waveform quality pro-actively, a measure has been introduced which assesses the number of complaints that are correlated with voltage waveform quality problems. Such "verified" complaints are determined by assessing the compliance of the licensee with the provisions of NRS-048-2. Waveform quality is affected by the operation and design of the supply network, and by the combined effect of customers connected to the network. It is therefore difficult to guarantee that a specific site will not exceed the limits in any given year. A certain number of "verified" complaints may therefore expected. It is the licensee's responsibility to address these problems. Recurring problems and lack of action by the licensee to address these problems are likely to result in Non-Conformance Reports in terms of the Quality Management System of the licensee. Such statistics are also reported annual by licensees. Figure 1 shows the number of verified complaints per 1000 customers for each of the customer categories.


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Verified Voltage Waveform Quality Complaints

0

5

10

15

20

25

1998 1999 2000 2001 2002 2003

Year

No.

Per

100

0 C

usto

mer

s RuralUrban

Figure 7 National waveform quality performance trend

(verified complaints).

Verified Voltage Waveform Quality Complaints (Compatative: 2003)

0

5

10

15

20

25

RED 1 RED 2 RED 3 RED 4 RED 5 RED 6

Year

No.

Per

100

0 C

usto

mer

s RuralUrbanRural (national)

Figure 8 Comparative waveform quality performance trend (verified complaints).

In the case of permanently monitored sites, the number of sites exceeding the planning levels / compatibility levels are shown below. (see figure 3) Voltage Dip Performance: Distribution Licensee NRS-048-2:2003 has defined characterisatic dip performance in terms of dip windows and statistics based on the 95 percentile of sites and 50 percentile of sites. The updated national dip performance is shown below for the reporting year and the average performance since 1998. This performance reflects dips caused by events on the transmission network and within the distribution licensee networks. The total site sample is ……. HV sites and ….. EHV sites.



(nominal voltages) X1 X2 T S Z1 Z2


23

As per part 3 (*NOTE NRS-Part 3 does not

require)

35 24

35 24

25 24

40 24

40 24

10 24

> 44 kV to ≤ 132 kV 30 24

30 24

20 24

20 24

10 24

5 24



(nominal voltages) X1 X2 T S Z1 Z2 As per part 3 13

24 10 24

5 24

7 24

4 24

2 24

> 44 kV to ≤ 132 kV 8 24

9 24

3 24

2 24

1 24

1 24

Note that these statistics reflect the dip performance for sites with an annual data availability as per NER requirements. Where 100% availability was not achieved, the data has been annualised. Voltage dip performance is strongly influenced by annual weather patterns, and for this reason a year-on-year comparison of dip performance is not a good indication of actual performance trends (particularly in the case of a single site). The figure below shows the trend in the 3-year average for the various dip categories. The average represents the average number of dips seen by all sites over a three year period ending at the year indicated.

HV Dip Performance Trend (Average over a 3-year window)

0

5

10

15

20

25

30

35

40

45

50

2000 2001 2002 2003

Reporting Year

Num

ber o

f dip

s X1X2STZ1Z2

Figure 10 National dip performance trend (all monitored sites).


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Comparative Dip Performance

0

5

10

15

20

25

30

35

40

45

50

RED

1 X

1

RED

2 X

1

RED

3 X

1

RED

4 x

1

RED

5 X

1

RED

6 X

1

RED

1 X

2

RED

2 X

2

RED

3 X

2

RED

4 X

2

RED

5 X

2

RED

6 X

2

RED

1 T

RED

2 T

RED

3 T

RED

4 T

RED

5 T

RED

6 T

RED

1 S

RED

2 S

RED

3 S

RED

4 S

RED

5 S

RED

6 S

RED

1 Z

1

RED

2 Z

1

RED

3 Z

1

RED

4 Z

1

RED

5 Z

1

RED

6 Z

1

RED

1 Z

2

RED

2 Z

2

RED

3 Z

2

RED

4 Z

2

RED

5 Z

2

RED

6 Z

2

Num

ber o

f Dip

s

Figure 11 Comparative dip statistics (range per dip category per RED): all dips at transmission delivery points.

A Review of Complaint Statistics Background The NER uses statistics provided by licensees on the number of Non-Conformance Reports (NCR's) raised in the reporting year to assess areas where specific problems exist, and to track the resolution of these. It is anticipated that for at least the next 3 years the number of NCR's will increase as customers become aware of their rights in terms of the NER Directive, and as licencees build the capacity and skills to deal with the complaints process. As such, an increase in these figures alone should not be interpreted as a negative trend in licensee performance. An important statistic is the number of disputes not resolved within 6 months, as this indicates that the industry is not dealing effectively with customer complaints. (Resolution by the NER of a dispute is a negotiated or arbitrated decision on the resolution to the problem. Resolution of an NCR is an agreement between the licensee and the customer on solving the problem.)

0 5 10 15 20 25

Number

TX

RED 1

RED 2

RED 3

etc

Lice

nsee

Non-Conformance Reports and Dispute Statistics

NCR ResolvedNCR UnresolvedDispute ResolvedDispute Unresolved

Types of Complaints Resulting in NCR's An important role of NCR and Dispute statistics is to identify problems areas in which stakeholders (licensees, the NER, customers, and equipment suppliers) have problems in


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meeting customer requirements. Based on an analysis of the annual returns, the NER Advisory Committee will address specific problems by considering aspects such as improved standards, specific requirements of licensees, improved communication, and the identification of precedents. The highest majority (e.g 60%) of all NCR's are in (e.g. rural) or "undefined" areas. Most of these (e.g. 80%) were related to either dips or interruptions. Industrial and agricultural customers make up the majority of complainants (70%). The total number of disputes unresolved for greater than 6 months was 5. The reason for the difficulties in resolving disputes is ……. The above indicators highlight a need for the Power Quality Advisory Committee to address the following quality issues in the coming year: - Improved interruption performance in rural areas with ,,,,, industry

Inte

rrupt

ions

Dip

s

Vol

tage

Unb

alan

ce

Har

mon

ics

Flic

ker

Oth

er

Indu

stria

l

Com

mer

cial

Agr

icul

tura

l

Res

iden

tial

Re-

dist

ribut

or

Var

ious

(gro

up a

ctio

n)

Oth

er

0

1

2

3

4

5

6

7

8

9

10

Complaint Category Customer Category

NCR and Customer Categories

Results of Dispute Resolutions The results of dispute arbitrations may provide potential precedents for similar future customer complaints. The following rulings / or agreement between the parties may be highlighted for the reporting year: - (e.g. where a customer is informed of the levels of dip performance and fails to take

adequate precaution against these in the design process……..) - …. Conformance to the Requirements of the NER PQ Directive Background The NER Directive requires each licensee to have in place a Quality Management System that meets minimum requirements specified by the Power Quality Advisory Committee (document ref.). This is a licence condition of each of the licensees. Conformance to these requirements is verified by the NER, where necessary, through consultation with the Power Quality Advisory Committee. Licensee Quality Management Systems As at 31 December, certificates of compliance were maintained by …. Licensees. …. Licensees remain only partially compliant, and ……. Licensees are not compliant.


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Compliance audits undertaken by the NER on a sample of licensees have revealed the following trends in the implementation of quality management systems: •

•

•

Itemised …. Fines Issued By The NER A core requirement of the Quality Management System is that licensees maintain records of formal customer complaints. Where such records are found not to have been kept when a dispute is escalated to the NER, the NER may issue a fine of up to R…………. In the reporting year, the following fines were issued:

Itemised …. Audit Results In the reporting year, the NER has undertaken audits of the Quality Management Systems of the licensees in accordance with the audit plan drawn up by the Power Quality Advisory Committee.

Itemised ….


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ANNEX E: ANALYSIS OF REPORTED RESULTS Generic Format Background The generic analysis of annual performance returns is based on assessing: • •

Historical trends Comparative performance.

Structure The structure of this is illustrated in the diagram below for distribution licensees (future RED's). In the case of Transmission, the same analysis is proposed - where the "licensee" column will represent the regional performance (i.e. Transmission performance to a particular RED).

Licen

see

ALic

ense

e B

Licen

see

N

Natio

nal

Year 1

Year 2

Year n

A B ..N NationalLicenseeAverage

(m years)

current year n average m years

Comparative Performance

1 2 ..nYear

licensee national (year n)

Performance Trend

licensee trend national trend

Figure G.1 Generic structure of the analysis of data. The following may be noted: • •

The average over m years is for a user-defined number of years. The rule for the calculation of the national statistic may be different for different parameters. In some cases (such as transmission returns) this will be provided by the licensee (i.e. does not need to be calculated from the individual performance).


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ANNEX E: GLOSSARY OF TERMS AND ABBREVIATIONS IR Incident Report NER National Electricity Regulator NCR Non-Conformance Report PQ Power Quality PQMS Power Quality Management System

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