High Voltage Electrical Equipment Failure Diagnosis. Presented by: Spencer Tang & Terence Ng T&T Inspection & Engineering Sdn Bhd

High Voltage Electrical Equipment Failure Diagnosis Presented by: Spencer Tang & Terence Ng T&T Inspection & Engineering Sdn Bhd

High Voltage Electrical Equipment Failure Diagnosis Definition of High Voltage (H.V. / H.T.) According to IEC standard, High voltage is defined as those with more than 1000V (>1000V AC) for alternating current low voltage (50~1000V AC) and extra-low voltage (<50V AC) circuits, in the context of building wiring and the safety of electrical apparatus. In South East Asia, HV is ranging from 1kV (1000V), 3.3kV, 6.6kV, 11kV, 22kV, 33kV, 132kV, 230kV, 275kV, 400kV & 500kV. Ultrasound World VII 2011 2

Map of the Asean Ultrasound World VII 2011 3

High Voltage Electrical Equipment Failure Diagnosis Characteristic of High Voltage Higher voltage required higher insulation level Ability to penetrate insulation material (air, vacuum, gas, oil, XLPE, PILC, porcelain, etc) due to deterioration / aging / interruption / human error, etc and create short circuit / discharge between phase to phase / phase to ground resulting severe facility damage / loss, injury / death Ultrasound World VII 2011 4

High Voltage Electrical Equipment Failure Diagnosis NDT Technology of Ultrasound a method to detect HV fault symptom (electrical partial discharge E.P.D.) from a safe distance Provide safe access via structure borne and airborne method without direct expose to the live part / component. Highly sensitive ultrasound instrument coupled with qualified inspector will able to detect HV fault symptom (eg( eg: : corona, tracking, arcing, mechanical looseness and etc) Ultrasound World VII 2011 5

E.P.D. at 33kV VCB Cable VOID Cable insulation void at cable compartment Ultrasound World VII 2011 6

E.P.D. at 33kV VCB Cable VOID Cable insulation void at cable compartment 2007 Jul 2008 Oct 2008 Ultrasound World VII 2011 7

E.P.D. at 33kV VCB Busbar Busbar insulation deterioration corona partial discharge Ultrasound World VII 2011 8

E.P.D. at 33kV VCB Breaker Contact Chemical reaction on conductor Ultrasound World VII 2011 9

E.P.D. at 132kV Lightning Arrester Internal partial discharge at porcelain Ultrasound World VII 2011 10

E.P.D. at 33kV Overhead Disc Isolator Airborne detected PD at disc isolator suspension clamp sharp edges/ oxidization / deterioration Ultrasound World VII 2011 11

High Voltage Electrical Equipment Failure Diagnosis mechanical vibration / looseness in HV breaker causes by the resonance of electrical frequency (50Hz / 60Hz) or electrical harmonics workmanship issue during on site installation (eg:: tightening / torque, panel and floor leveling, greasing, etc) Operator ignorant or mechanism error (eg( eg: breaker misalignment, breaker arm bent, shutter jammed, etc Ultrasound World VII 2011 12

Mechanical vibration / looseness in HV breaker Looseness detected at breaker & busbar Ultrasound World VII 2011 13

High Voltage Electrical Equipment Failure Diagnosis Repair urgency on partial discharge detected: Rate of deterioration Location of the PD detected Loading fluctuation - on/off, surge start, peak load Surrounding environment condition seaside, chemical industry, dusty area External factors animal, human error Ultrasound World VII 2011 14

Repair urgency on PD detected 11kV CT flashover during breaker surge start after maintenance due to ignorant Ultrasound World VII 2011 15

Repair urgency on PD detected Dusty and salty environment induced speedy deterioration at 33kV VCB Ultrasound World VII 2011 16

Repair urgency on PD detected High moisture environment induced oxidization & chemical reaction Ultrasound World VII 2011 17

Repair urgency on PD detected PD chemical effect on metal panel Before After Ultrasound World VII 2011 18

Repair urgency on PD detected Close PD location increase rate of deterioration Ultrasound World VII 2011 19

Repair urgency on PD detected External factor Minor corona partial discharge give way in 7 days due to road construction Ultrasound World VII 2011 20

Repair urgency on PD detected Client common question to inspector: How long does the PD symptom can last before it flashover?? Can we arrange shut down after our production peak time, may be about 6 months later?? Should we shut down by tonight?? Ultrasound World VII 2011 21

Perfect match of Ultrasound and Thermography Ultrasound (US) hear what we cannot hear; Thermography (IR) see what we cannot see. Technology limitation but not weakness. Integration of US & IR will supplement the survey findings and produce a better diagnosis result Ultrasound World VII 2011 22

Perfect match of Ultrasound and Thermography 11kV RMU required immediate attention y y 39.0 C 39.0 C 35 35 Sp1:temp 32.0 30 Ar1:max 34.5 30 26.0 26.0 Ultrasound World VII 2011 23

Perfect match of Ultrasound and Thermography Localizing the fault area FLIR Systems 70.0 C FLIR Sys tem s 40.0 C 60 38 Sp1:temp 44.6 50 36 34 40 32 Ar1:max 67.6 30 30 25.0 29.0 Ultrasound World VII 2011 24

Perfect match of Ultrasound and Thermography Localizing the fault area 31.9 C y 39.0 C 30 35 Ar1:max 36.1 30 27.0 28 24.0 Ultrasound World VII 2011 25 25

High Voltage Electrical Equipment Failure Diagnosis NDT technology ease the inspector / owner to visualize & localize the faults How is the HV partial discharge look like in our visual view??? Tx HV corona ring; 43.0 C Ar2:max 40.2 40 Ar3:max 30.5 30 Ar1 :max 40.1 20 19.0 Ultrasound World VII 2011 26

Tx HV Cable - corona ring partial discharge Ultrasound World VII 2011 27

Tx HV bushing partial discharge Ultrasound World VII 2011 28

Tx HV bushing partial discharge Ar3:max 44.3 50.0 C Ar2:max 49.1 45 Ar1:max 46.1 38.0 40 Ultrasound World VII 2011 29

Electrical partial discharge effect to plant/climber Ultrasound World VII 2011 30

HV flashover Ultrasound World VII 2011 31

High Voltage Electrical Equipment Failure Diagnosis To conduct a safe and effective inspection on high voltage electrical equipment, we should well understand and aware on: The safety measure of the HV equipment to be inspected; Our NDT instruments strength and limitation; Be observant and sensitive to the on-site condition of the HV equipment; a a careful inspector will live longer than a hero (fool) in HV electrical system Ultrasound World VII 2011 32

230kV GIS FLIR Systems 46.0 C 45 40 35 :max 32.8 :max 30.7 30 :max 30.8 FLIR Systems 25.0 46.0 C 45 40 35 30 25.0 Ultrasound World VII 2011 33

230KV GIS FLIR Systems 46.0 C 45 40 :max 32.8 :max 30.9 35 30 25.5 Ultrasound World VII 2011 34

3MVA Pauwels Trafo Ultrasound World VII 2011 35

Ultrasound World VII 2011 36

High Voltage Electrical Equipment Failure Diagnosis Glad to share with you, Thank you Ultrasound World VII 2011 37