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2 Introducing Acoustic Inspection Technology for Improving Network Reliability Goran Stojadinovic, Innovation and Technologies Manager Northpower, New Zealand Pacific Power Association Conference Tonga, 1 – 5 August 2016

“Renewable Energy Integration: Are Pacific Island Utilities Ready?” Objective: Seamless integration of Distributed Energy Resources (renewables) with traditional networks Pre-conditions: Network reliability and performance (SAIDI) Network & public safety Operational & cost efficiencies Enablers: Rapid & cost-effective inspection and condition monitoring Early detection of pre-fault conditions and defect prioritisation Tool for continuous improvement of network design & work practices Additional Gains: Extension of useful life of existing assets Significant reductions in unnecessary expenditure 3 Pacific Power Association Conference, Tonga, 1-5 August Northpower & West Coast Energy

FORESIGHT A new inspection method for overhead power lines State-of-the-art acoustic inspection technology for all OH networks from 6kV to 220kV Comprehensive diagnostic service, customised to individual network owner/operator needs 4 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

FORESIGHT Technology Developed and patented by UIT Networks, Korea in 2008 for Korean electricity network (KEPCO) Detection of ultrasonic signal caused by any electrical discharge, including PD and corona Early detection of electrical defects Ultrasonic range: 20kHz to 150kHz Voltage Range: 6kV to 220kV AC Used in 10 countries on over 12 million poles/structures & associated power lines 5 Pacific Power Association Conference, Tonga, 1-5 August Northpower & West Coast Energy

FORESIGHT Inspection Method Rapid - from a vehicle at approx. 30km/h (in urban areas) Remote feeders - from a 4WD vehicle or on foot (as required by terrain/access) Detection range up to 45m High resolution photography of defective components (in support of defect reporting) Defect classification in accordance with network standards Failure and Severity Timeframe Fault - Report to Asset Owner immediately Replace or Repair < 3 months Repair or Replace < 12 months Replace or Repair 1-3 year timeframe Review at next inspection Priority Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

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Foresight Ultrasound Technology EMI (RFI/TVI) Detectors Partial Discharge (PD) Instruments combining two types of detectors - TEV and Ultrasound Corona CameraThermal Imaging Camera DetectsUltrasonic signal caused by any electrical discharge, including PD and corona Electro Magnetic Interference caused by power lines in Radio/TV spectrum Capacitive leakage to earth through voids in insulation, creating Transient Earth Voltages and Ultrasound Ultrasonic discharge caused by steady glow or brush discharge in air Infrared radiation Frequency range 20 – 150kHzRadio/TV range TEV - in MHz Ultrasound - 40kHz 20MHz – 100MHzInfrared spectrum ReceiverMicrophoneAntennae (dish) TEV detector Dish-shaped ultrasound detector (traditional) ‘Ultrasonic’ discharge detector IR detector Truly Directional YesNo Yes Suitable forOH network GM network, limited use in OH applications OH networkGM/OH network Drive byYesNo Detection accuracy Pinpoint accuracyLimited Accurate (*) Number of inspections per day 300 distribution poles along roads Less than 30 8 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Experience Networks: 3 years of inspection of electricity networks in New Zealand, Australia, Pacific and in mining industry in Australia Distribution, subtransmission & transmission OH lines (6kV – 220kV) Outdoor switchyards HV Aerial Bundled Conductors (ABC) Single Wire Earth Return system (SWER) 9 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Experience Inspection record: 150,000 poles/structures & associated lines 2,000 electrical defects Most of these defects had not been previously detected with traditional inspection methods Most of these defects had a potential to adversely impact network reliability, SAIDI, safety & operational costs 10 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Galvanic Corrosion Increased contact resistance on cable termination (aluminium – steel – cooper) 11 1 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Galvanic Corrosion Increased contact resistance 12 1 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Galvanic Corrosion Exposed Bimetal Compression Ferrule on cable termination (aluminium – c ooper) 13 1 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Galvanic processes – end result (33kV cable termination) 14 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Increased contact resistance – Incorrect installation of Ampact connector (galvanic corrosion, overheating) 15 5 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Increased contact resistance – Inappropriate use of IPC connector (galvanic corrosion, overheating) 16 2 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Increased contact resistance on DO fuse dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Increased contact resistance on transformer connections (loose connection, corrosion, overheating) 18 4 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Increased contact resistance on cable termination (loose contact, overheating) 19 Missing spring washer 5 dB 8 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Increased contact resistance – end result 20 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Increased contact resistance on conductor joint 21 1 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Intermittent contacts – incorrect installation of tie-wire/binder (conductor erosion, arcing between the conductor and tie-wire) 22 3 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Intermittent contacts - end result (heavy conductor erosion, arcing between broken strands) 23 3 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Reduced Clearance Distance (conductor erosion) 24 3 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Reduced Clearance Distance – end result 25 3 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Vegetation (conductor erosion) dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Reduced Leakage/Creepage Distance (porcelain, ceramic, polymer, glass insulators – cracks, contamination, flashovers, pin rust etc.) 1 dB 6 dB 27 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Cement compound crack and pin rust (capacitive discharge, imminent glass crack) 28 1 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Cable termination defects (dry-bands, tracking, PD etc) dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Cable termination defects – end results 30 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Air Break Switch (ABS) defects 31 1 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Air Break Switch (ABS) defects 32 4 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Surge diverter internal leakage (33kV) 33 2 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Transformer & Gas Insulated Switch (GIS) defects 15 dB 12 dB 14 dB 34 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Transmission lines: Reduced Leakage/Creepage Distance (220kV) 35 7 dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Conductor support & suspension clamp defects (132kV) dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Conductor support & suspension clamp defects (220kV) dB Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Suspension and support clamp defects – End result (220kV) 38 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Suspension and support clamp defects – End result (220kV) 39 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Examples of sound waves and sound power level 1 dB15 dB 27 dB 40 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Case Studies Number of electrical defects identified using FORESIGHT & traditional methods: None of these defects were previously identified using traditional techniques. Under ideal environmental & operating conditions 25 – 30% could have been detected using traditional inspection methods. Case study#1: Distribution (11kV and 33kV) #2: Intermittent fault on 33kV #3: Distribution & transmission (11kV, 33kV, 220kV, and outdoor switchyards) Number of poles/structures inspected Over 2,000 Number of electrical defects identified by FORESIGHT Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Key benefits Early detection of pre-fault conditions Improved network reliability, SAIDI & safety Significant operational & cost efficiencies (i.e. savings on inspections, maintenance & network outages) Improved defect classification, prioritization & tracking of asset condition over time Great success in finding the true root causes of intermittent faults Feedback tool for continuous improvement of network design & work practices 42 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

Conclusion Advantages of FORESIGHT over traditional asset inspection methods : Superior detection of electrical defects 10 x Faster - Rapid & cost-effective inspection (up to 300 distribution poles or 50 transmission structures per day, including associated lines) Pinpoint accuracy Comprehensive risk management solution FORESIGHT can make a significant contribution to seamless integration of Distributed Energy Resources. 43 Pacific Power Association Conference, Tonga, 1-5 August Northpower and West Coast Energy

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