Insulator Replacements

Transcription

1 A REPORT TO THE BOARD OF COMMISSIONERS OF PUBLIC UTILITIES Insulator Replacements Electrical Mechanical. Civil Protection & Control Transmission & Distribution Telecontrol System Planning HYDRO THE POWER OF COMMITMENT NEWFOUNDLAND AND LABRADOR HYDRO

2 Table of Contents 1 INTRODUCTION PROJECT DESCRIPTION EXISTING SYSTEM Age of Equipment or System Major Work or Upgrades Anticipated Useful life Maintenance History Outage Statistics Industry Experience Maintenance or Support Arrangements Vendor Recommendations Availability of Replacement Parts Safety Performance Environmental Performance Operating Regime JUSTIFICATION Net Present Value Levelized Cost of Energy Cost Benefit Analysis Forecast Customer Growth Energy Efficient Benefits Legislative or Regulatory Requirements Historical Information Losses during Construction Status Quo Alternatives CONCLUSION Budget Estimate Project Schedule...12 Newfoundland and Labrador Hydro i

3 1 INTRODUCTION In the 1960s and 1970s Newfoundland and Labrador Hydro (Hydro) was using Canadian Porcelain (CP) and Canadian Ohio Brass (COB) pin type and suspension type insulators in distribution line construction. Industry experience has shown the porcelain in these insulators is prone to failure caused by cement growth. Cement growth is the expansion of the material which holds in place the pin that supports the connection of the insulator to the pole or to the conductor. Cement growth causes hairline cracks to appear in the porcelain, thereby, weakening the insulator. This leads to electrical and mechanical breakdown. Over the past ten years, Hydro has been replacing CP and COB insulators with Hydro's new standard 34.5 kv Post type clamp top or 35kV Hendrix vise top and the suspension type insulators will be replaced with the new standard Polymer. The Jackson s Arm Line 1 (L1) and Line 2 (L2) and the Hampden Line 1 (L1) distribution lines were built in Jackson s Arm L1 services the communities of Jackson s Arm, Wick s Cove, and Godfather s Cove while Jackson s Arm L2 services Schooner Cove, Sop s Arm, Burnt Head Cove, and Pollard s Point. Hampden L1 serves the communities of Hampden, Bay Side, and The Beaches and Rooms located in the vicinity of White Bay in the central area of Newfoundland. The Little Bay Line 2 (L2) distribution line was built in 1974 and serves the community of Beachside. Newfoundland and Labrador Hydro Page 1

4 2 PROJECT DESCRIPTION The project will include the replacement of 2,270 insulators on the Jackson's Arm distribution feeders L1 and L2 and on the Hampden distribution feeder L1. It will also include the replacement of 270 insulators on the Little Bay distribution feeder L2. Newfoundland and Labrador Hydro Page 2

5 3 EXISTING SYSTEM Jackson s Arm L1 is a 12.5 kv three-phase feeder that extends from the Jackson s Arm Terminal Station to the community of Godfather s Cove covering a distance of approximately five kilometers and serving approximately 200 customers. Jackson s Arm L2 is also a 12.5 kv three-phase feeder that extends from the Jackson s Arm Terminal Station to the community of Pollards Point covering a distance of approximately 20 kilometers and serving approximately 300 customers. Hampden L1 is a 12.5 kv three-phase feeder that extends from the Hampden Terminal Station to the community of The Beaches and Rooms covering a distance of 22 kilometers and serving approximately 300 customers. Little Bay Line 2 is a 12.5 kv single-phase feeder that is approximately 6.2 kilometers long and extends from the Beachside substation to the community of Beachside. It serves approximately 100 customers. The existing insulators were installed when the lines were first constructed, have deteriorated over time, and need to be replaced to ensure a reliable source of power to Hydro s customers. 3.1 Age of Equipment or System Jackson s Arm L1, L2 and Hampden L1 were constructed in 1968 and Little Bay L2 was constructed in Newfoundland and Labrador Hydro Page 3

6 3.2 Major Work or Upgrades There have been no major upgrades on Jackson s Arm L1, Jackson s Arm L2, Hampden L1, or Little Bay L2 since the installation of the lines. 3.3 Anticipated Useful life The estimated service life of distribution feeders, for depreciation purposes, is 30 years. Newfoundland and Labrador Hydro Page 4

7 3.4 Maintenance History Table 1 shows the maintenance history for the Jackson's Arm, Hampden and Little Bay systems. Table 1 Jackson s Arm, Hampden and Little Bay Maintenance History Year Preventive Maintenance ($000) Jackson's Arm L1 and L2 Corrective Maintenance ($000) Total Maintenance ($ 000) Hampden L Little Bay L Newfoundland and Labrador Hydro Page 5

8 3.5 Outage Statistics Hydro tracks all distribution system outages using industry standard indexes, System Average Interruption Frequency Index (SAIFI) and System Average Interruption Duration Index (SAIDI). SAIDI and SAIFI are explained as follows: SAIDI - SAIFI - Indicates the system average interruption duration for customers served per year or the average length of time a customer is without power in the respective distribution system per year. Indicates the average of sustained interruptions per customer served per year or the average number of power outages a customer has experienced in the respective distribution system per year. Table 2 below lists the 2003 to 2007 average SAIFI and SAIDI data for the Jackson s Arm, Hampden and Little Bay systems, the 2003 to 2007 corporate values, and the latest CEA five-year average (2002 to 2006) for comparison. These reliability statistics are not the justification for this project. The insulators on these distributions lines were identified as needing replacement during the last line inspections in Table 2 SAIFI and SAIDI Five Year Average Indices ( ) All Causes Defective Equipment SAIFI SAIDI SAIFI SAIDI Jackson s Arm System Line Line Hampden System L Little Bay System Line Hydro Corporate CEA ( ) Newfoundland and Labrador Hydro Page 6

9 3.6 Industry Experience As explained in the introduction of this document, the utility industry has experienced widespread failure of CP and COB insulators. 3.7 Maintenance or Support Arrangements A complete inspection of the Jackson s Arm L1 and L2, Hampden L1, and Little Bay L2 feeders is performed every nine years to evaluate the condition of the lines. The last inspection was performed in The inspection is completed by Hydro personnel and any corrective maintenance required is reported, scheduled and performed. 3.8 Vendor Recommendations There are no specific vendor recommendations for this project. The existing pin type insulators will be replaced with Hydro's new standard 34.5kV post-type clamp top or 35kV Hendrix vise top and the suspension type insulator will be replaced with the new standard Polymer. 3.9 Availability of Replacement Parts Availability of replacement parts is not a consideration for this project Safety Performance Mechanical breakdown of the insulators is a safety issue for the line workers of Hydro. The insulators are prone to hairline cracking in the porcelain thus reducing their mechanical strength and increasing the chance of breaking during climbing activities by maintenance crews. This increases the potential for injuries to Hydro personnel. Newfoundland and Labrador Hydro Page 7

10 3.11 Environmental Performance Environmental performance is not a consideration for this project Operating Regime The Jackson s Arm, Hampden and Little Bay feeders are in continuous operation providing power to approximately 900 customers. Newfoundland and Labrador Hydro Page 8

11 4 JUSTIFICATION The insulators used on these lines have been failing throughout the industry, due to cement growth causing radial cracking and weakening of the insulators. Replacement of these insulators is essential to improve system reliability. 4.1 Net Present Value A Net Present Value calculation was not performed in this instance as only one viable alternative exists. 4.2 Levelized Cost of Energy This project will have no effect on the levelized cost of electricity. 4.3 Cost Benefit Analysis As there are no quantifiable benefits, a cost benefit analysis has not been performed. 4.4 Forecast Customer Growth Customer load growth does not affect this project. 4.5 Energy Efficient Benefits There are no energy efficiency benefits that can be attributed to this project. 4.6 Legislative or Regulatory Requirements There are no applicable legislative or regulatory requirements. Newfoundland and Labrador Hydro Page 9

12 4.7 Historical Information The table below lists insulator replacement projects in the last five years. Cost per unit has increased mainly due to increased contract labour costs. 4.8 Losses during Construction There are no anticipated energy losses during construction. Table 3 Five Year History of Insulator Replacement Projects - Cost per Unit Capital Actual Cost per Budget Expenditures Comments Year Units unit ($000) ($000) ($000) project , projects , projects , projects , projects 4.9 Status Quo The status quo is not an acceptable alternative. The existing equipment is in a deteriorated condition. Failure to replace the identified insulators could result in an increase in the number outages of varying durations to the customers in the area. Deteriorated insulators pose a significant risk to regulated operations personnel with the potential of failure during climbing activities by line workers Alternatives There are no viable alternatives to this upgrade work. Newfoundland and Labrador Hydro Page 10

13 5 CONCLUSION This project is required to ensure that a reliable energy supply is available for the customers served by the Jackson s Arm L1, L2, Hampden L1 and Little Bay L2 feeders. 5.1 Budget Estimate The estimate for these projects to be completed in 2009 is $874,200. Jackson s Arm and Hampden insulator replacements will be completed as one project. Table 4 Budget Estimate Jackson's Arm, Hampden and Little Bay Jackson s Arm Project Cost:($ x1,000) & Hampden Little Bay TOTAL Material Supply Labour Consultant Contract Work Other Direct Costs O/H, AFUDC & Escln Contingency TOTAL Newfoundland and Labrador Hydro Page 11

14 5.2 Project Schedule Table 5 Project Schedule Activity Milestone Initiation January 2009 Design Complete March 2009 Equipment Ordered April 2009 Installation Commences July 2009 Installation Complete August 2009 Project Closeout September 2009 Newfoundland and Labrador Hydro Page 12