National Electric Power Regulatory Authority (NEPRA) has released the performance evaluation report 2021-22 of National Transmission and Despatch Company (NTDC) and K-Electric.
The report provides information on the performance of NTDC and K-Electric (KE) taking into account system reliability, security of supply and quality of supply of the transmission network of the licensees during the reported period.
The National Electric Power Regulatory Authority (NEPRA) is the regulator of the power sector in Pakistan. Provision of safe, reliable, efficient and affordable electric power to the electricity consumers is an integral part of NEPRA’s regulatory regime.
In order to ensure safe, efficient and reliable transmission services, NEPRA has framed the Performance Standards (Transmission) Rules (PSTR)1 2005. Under PSTR, a transmission licensee is required to submit to NEPRA an Annual Performance Report (APR) in a manner as prescribed in PSTR.
The APRs for the FY 2021-22, submitted by NTDC and K-Electric were reviewed and analysed in light of the performance parameters such as system duration of interruption, system frequency of interruption, energy not served (ENS), loss of supply incidents along with its financial impact, amount allowed for improvement, voltage and frequency violation limits prescribed under the PSTR, and highest and lowest voltage recorded at NTDC 500 kV and 220 kV grid stations under Normal system conditions.
In its recommendations given in the report on NTDC and KE, NEPRA suggests that the equipment which has exhausted its useful life should be replaced with new machinery and equipment at all the grid stations, as and when required.
Similarly, short circuit studies should be carried out at all grids to determine the actual fault level for proper primary equipment selection and installation.
Likewise, event fault recorders should be installed for better fault analysis to avoid outages. Furthermore behavior of bus-bar protection relays should be reviewed and tested thoroughly to avoid cascaded outages.
Adding that, NTDC should complete the system constraints removal projects to eradicate the financial impact caused due to merit order violation.
In the report NTDC was also urged to focus on power evacuation projects to bring in most economical power into the national grid at the earliest. A recent example of it is the issue of evacuation of energy being produced by power plants using Thar coal due to infrastructure constraints.
Moreover, the KE being the responsible entity for providing reliable power to the city of Karachi, the economic hub of the country, “it is of paramount importance to take measures/steps to operate in island mode in the event of external major incidents to avoid unnecessary power cuts”, stated the NEPRA report.
Performance of the NTDC and KE
The report is structured to understand the overall performance of the energy supply chain. The performance is judged by various indicators prescribed by NEPRA.
System Duration of Interruption
System duration of interruption is a reliability indicator that measures the average outage duration that an interconnection point observes in a year.
The interruption for NTDC was witnessed around 0.15 hours (9 minutes) in the year 2021-22 indicating 15.4% increase as compared to preceding year i.e. 0.13 hours (8 minutes).
System duration of interruption was not witnessed in the KE system during the recorded period, which shows 100% reduction as compared to preceding year’s average of 0.06 Hours (4 minutes).
System Frequency of Interruption
System frequency of interruption is another reliability parameter that measures the average number of outages per circuit in a year. During 2021-22 the average number of outages per circuit for NTDC remained 0.10, showing an improvement of 10% over the previous year i.e. 0.11.
In the jurisdiction of KE, System frequency of interruption was observed as 0 number of outages per circuit. It indicates a decrease of 100% over the previous year which stood at 0.02.
Energy Not Served (ENS)
In order to gauge system security, the estimates of total ENS during the year as reported by the licensees have been analysed. The total ENS as reported by NTDC in 2021-22 is 9.4 million kWh whereas in the case of KE the total ENS reported is zero.
Looking at the data of NTDC this indicates an improvement of around 93% compared to the previous year i.e. 130.2 million kWh. Based on the average sale rate of DISCOs, the financial impact amounts to around Rs 93 million.
Loss of Supply Incidents
NTDC reported 51 loss of supply incidents during the year 2021-22 which translates into a total duration of 80 hours. NEPRA took serious notice of the partial collapses.
The reports submitted by NTDC also revealed serious lapses on the part of the despatch company. Based on the reports, NEPRA initiated legal proceedings and imposed a fine of Rs.10 Million on NTDC.
It was also observed that after the blackout of 9th January 2021, NTDC was directed to make certain improvements in its transmission network for the improvement of system reliability, stability and security of supply.
However, recent events and multiple outages in NTDC’s network during the FY 2021-22 indicates that adequate measures have not been taken by NTDC in this regard, said NEPRA report.
Transmission network being the backbone of the country’s electric power supply system, the Authority allowed a colossal amount of Rs 790 million to NTDC under repair and maintenance (R&M) to ensure and attain optimal level of network reliability and sustainability.
However, the monitoring activities carried out by NEPRA during the period revealed that the southern part of the network is vulnerable to frequent outages that lead to major system disturbances owing to aging of equipment and tower collapses, which has been highlighted in the NEPRA report.
Voltage Violations
The equipment’s performance suffers from voltage fluctuations, which also make the internal voltages and currents of electrical devices unstable. This can lead to short circuiting and damaged equipment.
The rules prescribed by NEPRA call for limits in voltage variations. However the number of voltage violations for NTDC remained 185,497 for the year 2021-22 that indicates a 54.5% increase as compared to 120,092 violations in the preceding year.
Whereas KE has reported 46 voltage violations under normal conditions that indicates 100% increase with respect to the preceding year.
The highest voltage recorded beyond permissible limits at 500 kV voltage class was 564 kV, recorded at D. G. Khan. Similarly, at 220 kV level, highest voltage was 250 kV recorded at Muzaffargarh while at 220 kV level, the voltage remained as low as 150 kV, recorded at Kala Shah Kaku and 170 kV at Quetta.
Frequency Violations
Similar to the impact of voltage fluctuations, several electrical frequencies cannot coexist without causing device damage, hence maintaining a constant electrical frequency is crucial.
NEPRA has prescribed limits for frequency variations under the Rules. The frequency data as reported by NTDC indicated variation in frequency limits beyond the upper permissible limit of 50.5 Hz.
Whereas the highest frequency recorded was 50.66 Hz that comes out to be 1.3% variation against the allowed limit of 1%. However, NTDC has violated the prescribed limits 4 times for a total of 26 minutes.
According to the report, during 2021-22, in the KE system there was only a single instance when frequency remained outside the prescribed limit (upper) i.e. 50.53Hz for 9 minutes and that comes out to be approximately 0.002% of the reported period.
It is pertinent to highlight that during the reported period two partial collapses occurred and KE’s system collapsed as well that nullifies its stance of zero outages.
Furthermore, it is important to highlight that KE being a vertically integrated utility having a generation fleet of around 2,817 MW has failed to survive during major incidents repeatedly which is a matter of serious concern.
Supervisory Control and Data Acquisition (SCADA) System
The complexity of the modern day power systems require automation for real time data acquisition enabling quick and intelligent decisions for supervision, monitoring and control of the transmission system.
NEPRA has long been emphasising a need to deploy a modern SCADA System by NTDC to supervise and control the economic despatch of electric power generation which is yet to be implemented.
The Authority has allowed Rs 3.4 billion to NTDC in the last three years for installation and commissioning of SCADA system and services as per request of the despatch company, which has yet to fully implement it.
System Constraints and Overloading of Transmission Network
During the reported period, at several instances, the transmission system remained incapable of transmitting the electric power from efficient power plants to load centres to meet the demand.
NTDC is still requiring a longer period to fix the existing constraints which is a leading cause in the acquisition of electricity in violation of the merit order.
In the report NTDC has also been urged to take measures to remove constraints in its network to off-take electric power from existing power plants as well as upcoming power projects in light of the Transmission System Expansion Plan (TSEP) duly integrated with the plan for induction of new generation plants in accordance with Indicative Generation Capacity Expansion Plan (IGCEP).
Similarly, the data pertaining to system constraints revealed that most of the grid stations are overloaded and NTDC’s progress on removal of system constraints is slow and around 11 projects have faced delays. NTDC needs to complete it on priority to avoid any adverse impacts on the power sector, said the NEPRA report.
Interconnection of new power plants
In various cases, NTDC was not able to complete the interconnection facilities for evacuation of power from new power plants as per the approved design, within the stipulated time period and thus caused under-utilisation of the available capacity.
It has also been observed that progress on evacuation projects is slow due to which cheap electricity located in Thar is not being supplied to the national grid.
Such as the absence of dedicated transmission line for Shanghai Electric Company Limited (SECL) plant, leads to load curtailment of Engro Power Thar Limited (EPTL) and Thar Energy Limited (TEL) due to inadequate transmission capacity.
NTDC needs to complete its evacuations projects on priority so that any adverse impact on the power sector may be avoided.
History
K-Electric (KE) formerly known as Karachi Electric Supply Company was established on September 13, 1913 under the Indian Companies Act of 1882 as the Karachi Electric Supply Corporation (KESC). The entity was nationalised in 1952 and privatised again on November 29, 2005. In September, 2008 it was renamed as Karachi Electric Supply Company (KESC). Thereafter, it was rebranded as K-Electric (KE).
KE was granted Transmission Licence on 10th June 2010 by NEPRA to engage in the transmission business within the territory as specified in its licence for a term of thirty (30) years.
KE’s transmission system comprises a total of 1,355 km of 220 kV, 132 kV and 66 kV transmission lines, 71 grid stations, 20 Auto Transformers and 175 power transformers, as of June 2022. K-Electric grid is interconnected with the NTDC grid system through four (04) 220 kV transmission circuits, namely;
- KDA-NKI
- Baldia-NKI
- KDA-Jamshoro-1
- KDA-Jamshoro-2
NTDC was incorporated under the Companies Ordinance 1984 on November 6, 1998. The principal business of NTDC is to own, operate and build infrastructure for transmission systems of 220 kV, 500 kV and above transmission Lines and associated Sub-stations.
NTDC commenced its commercial operation on 1st of March 1999 and was organised to take over the properties, assets, rights, obligations and liabilities of transmission networks all over Pakistan previously owned by Pakistan Water and Power Development Authority (WAPDA), except the area served by K-Electric.
NTDC was granted Transmission Licence on 31st December 2002 by NEPRA to engage exclusively in the transmission business for a term of thirty (30) years, pursuant to Section 17 of the Regulation of Generation, Transmission and Distribution of Electric Power Act, 1997.
NTDC operates & maintains seventeen (17) 500 kV and forty-seven (47) 220 kV Grid Stations with 8,387 km of 500 kV and 11,611 km of 220 kV transmission lines as of June, 2022.
