ABB November 25, 2016

Transcription

1 Johan Kristiansson, PGHV/High Voltage Surge Arresters - Africa Channel Partner event, 2016 ABB Africa Channel Partner event Line Surge Arresters - Contribution to Power Quality: Line Side Protection Slide 1

2 Company Location Ludvika Slide 2

3 ABB in Ludvika - The High Voltage Valley A power transmission center for more than 100 years 2600 employees Independent laboratories with latest technology Your one-stop source for high voltage products ABB in Ludvika is a leader in power transmission technologies that enable our customers to improve their performance while lowering environmental impact. Slide 3

4 Surge Overvoltages Can Cause Problems Impossible or uneconomic to withstand / avoid all overvoltages. Surge Arresters are needed to protect other equipment from insulation failure due to lightning and switching surges. Slide 4

5 Availability of Electric Power Supply EHV Transmission substation Transformer HV HV Main substation Secondary substation MV Distribution substation LV At each point, the consumer of electricity is concerned about Number and Duration of interruptions (plus associated costs) Slide 5

6 Acceptable Outage Rate - A Moving Target Single circuit Power in Transmission line Transformer Power out Double circuit Substation equipment Typically poor overall availability Substation equipment is not the critical factor during normal operation Line and transformer are dominating causes for unavailability Two lines in parallel Two transformers in parallel Power in S/S Power out Lightning is a significant contributing factor to the outage rate Line availability remains critical with common towers Double line failures must be avoided Slide 6

7 Why Is Lightning Mitigation Important for Transmission Lines? App. 65% of non-sheduled outages on transmission lines are related to lightning Consumers have become more demanding Computer controlled equipment Sensitive processes are dependent on constant and reliable energy supply Slide 7

8 Lightning Costs and Losses from Attributed Sources Lightning in South Africa is responsible for 65% of damage in distribution networks and 26% of the total number of line faults in transmission networks ( ) Faults on transmission lines in Korea ( ) Transmission Voltage Total Faults Lightning caused faults % 66kV % 154kV % 345 kv % SUM % Examples of plant losses due to lightning-induced electrical outage: South African South Deep JV mine lost 1 month production (2005) Porgera JV mine in Papua New Guinea lost 50% of electrical power for more than three months at a production loss of US$750,000/day (2006) Slide 8 Tennessee smelter pot line frozen. 164 pots have to be dug out by hand. Production is shut down for seven weeks (2007)

9 Movie Increasing Grid Reliability Movie Enabling Reliable Power Grids Slide 9

10 Slide 10

11 Risk for interruption minimized by using Line Surge Arresters Slide 11

12 Cause of lightning flashovers on HV transmission lines Backflashover High footing resistance Shielding failure No OHSW Poor shielding angle Induced flashover Lightning flashes to ground seldom exceed 200 kv Neglected on HV transmission lines due to high LIWL Slide 12

13 Reliability and Availability Improvements Measures Duplicate system Increase insulation withstand Very expensive and often impractical. Compromise with two lines on one tower. Expensive and creates insulation co-ordination problems Improve footing impedance Often difficult and expensive Shield wires Protect line insulation by surge arresters Requires low tower footing impedance. Problems of their own. Difficult to retrofit. Unlikely to achieve demanded reliability. Do not improve switching performance. Arresters connected in parallel with line insulators at selected towers. Line Surge Arresters (LSA) Slide 13

14 Transmission Line Protection - Benefits Arresters installed on selected towers eliminates disturbances caused by overvoltages Prevents lightning-induced flashover across line insulators on the tower Assists to extend line circuit breaker life and maintenance-interval Controlled switching surge overvoltage profile along the line Slide 14

15 Benefits to Users Increased availabillity of lines Reduced disturbance for sensitive industries Reduced number of CB operations Less stress on substation equipment Slide 15

16 Protection Philosophy Against Backflashovers Determine where to install LSA Locate areas with high footing resistance Low <20 ohm High >40 ohm Very High >100 ohm Hilly terrain Location with high lightning density System study Slide 16

17 Protection Philosophy Against Backflashovers Slide 17

18 Protection Philosophy Against Backflashovers Slide 18

19 Dimensioning Data Mechanical Tower and line configuration Line length Span length Single or double circuit Tower dimensions Type, location and sag of phase conductors and ground wires, etc Mechanical loading Wind, ice, etc Environmental Pollution, altitude, etc Slide 19

20 Dimensioning Data Electrical & Environmental Existing and desired outage rate Ground flash density or keraunic level System Uc and TOV Short-circuit current Amplitude & duration Insulation level for line insulation (CFO =critical flashover voltage) Tower grounding Earthing/footing resistance Soil resistivity Slide 20

21 Dimensioning Data Electrical & Environmental Slide 21

22 Dimensioning Data Electrical & Environmental Mean annual thunderstorm days Slide 22

23 Dimensioning Data Electrical & Environmental Slide 23

24 The ABB Solution PEXLINK: Secure Supply All the Way Slide 24

25 The ABB Solution PEXLINK: Secure Supply All the Way Assures disturbance-free operation of transmission lines Suitable for all voltage levels Eliminates disturbances caused by overvoltage Prevents lightning-induced flash-over across line insulators Controlled switching surge over-voltage profile along the line Fail-safe design with visible indication Easy to install Slide 25

26 The ABB Solution PEXLINK: Silicone-housed Arresters (PEXLIM) Arresters with lower or higher rated voltages may be available on request for special applications Description PEXLIM R PEXLIM Q PEXLIM P System voltages [kv] Rated voltages [kv] Nominal discharge current [ka peak ] Repetitive charge transfer rating (IEC , Ed. 3.0) [C] Thermal energy rating (IEC , Ed. 3.0) [kj/kv (U r )] Line discharge class (IEC , Ed 2.2) Class 2 Class 3 Class 4 Slide 26

27 The ABB Solution PEXLINK: Silicone-housed Arresters (PEXLIM) Silicone-housing gives exceptional service performance Direct vulcanising (bonding) of silicone onto active parts Active elements sealed along entire length Total absence of any air between the active elements and the housing No moisture leakage path No internal partial discharge No pressure build up during overload Unique open-cage design with belt-winding Short-circuit safe No collapse after short-circuit Excellent heat dissipation from MO varistors High thermal stability threshold Slide 27

28 The ABB Solution PEXLINK: Robust Terminations Slide 28 Strength of all connections and hardware must be robust to avoid mechanically related failures

29 The ABB Solution PEXLINK: Silicone-housed Arresters (PEXLIM) PEXLIM arrester provided with Line connector clamp Disconnecting device Clamps and conductors Standard available material can be used Disconnecting device Easy indication of failed arresters Permits re-energisation after fault without immediate attendance Linked to obtain safe physical disconnection Slide 29

30 The ABB Solution PEXLINK: Silicone-housed Arresters (PEXLIM) Slide 30

31 The ABB Solution PEXLINK: Silicone-housed Arresters (PEXLIM) Polymer housing is necessary Light weight Can be hung on existing towers and strings Easy transport up the towers & mounting Non-brittle Vandal-proof Safer under failed conditions Better pollution performance over long periods Specially true for silicone H High energy capability needed Transmission lines connected to stations should be protected by station class arresters with proven Lightning discharge capability. Slide 31

32 The ABB Solution PEXLINK: Silicone-housed Arresters (PEXLIM) Slide 32

33 The ABB Solution PEXLINK: Silicone-housed Arresters (PEXLIM) Slide 33

34 The ABB Solution PEXLINK: Silicone-housed Arresters (PEXLIM) Slide 34

35 The ABB Solution PEXLINK: References Mexico: 245 kv 420 kv Canada: 245 kv 550 kv 800 kv USA: 72 kv 123 kv 800 kv El Salvador: 52 kv 123 kv Norway: 300 kv 420 kv Denmark: 72 kv Poland: 72 kv Spain: 72 kv Croatia: 123 kv Italy: 170 kv Sweden: 52 kv 72 kv 145 kv 420 kv Finland: 123 kv Romania: 245 kv Slovenia: 123 kv Malaysia: 145 kv Russia: 123 kv, 420 kv Hong Kong (SAR): 145 kv Colombia: 245 kv Panama: 52 kv Peru: 24 kv 72 kv Costa Rica: 145 kv 245 kv Yemen: 145 kv Indonesia: 170kV Mauritius: 72 kv Philippines: 145 kv 245 kv Chile: 145 kv 245 kv Argentina: 245 kv Brazil: 72 kv 145 kv 245 kv Swaziland: 72 kv South Africa: 100 kv 145 kv 300 kv 420 kv Australia: 72 kv 145 kv Slide 35

36 Example of Installations Eskom (South Africa) Line name (275 kv) Line length (km) Installation date Units installed Performance (Faults/100km/year Before After Eiger-Prospect / Eiger-Fordsburg / Glockner-Olympus N/A 6.97 Taunus-Princess / Esselen-Pelly / Bighorn-Pluto Hera-Watershed Source: Cigré 5th Southern Africa Regional Conference, October 2005 Conclusion: Even with limited number of towers protected, the outage rate for the complete transmission line is greatly improved. Slide 36

37 The ABB Solution PEXLINK: Monitoring Of interest to monitor surges through individual LSA Sensor fitted to each LSA Remote communication Statistical analysis (software) Leakage current measurement only of academic interest Slide 37

38 Summary Line availability is a critical factor in overall network availability. Arresters installed on selected towers eliminates disturbances caused by overvoltages and assists to extend line circuit breaker life and maintenance-interval. Each point in the network is a consumer of electricity and the acceptable number of outages is a moving target. Network operators need to use all available methods to secure and improve power continuity. Slide 38

39 Summary Slide 39

40 Summary Slide 40

41 A Future Necessity to Help Keep the Lights On? Sensitive processes are all the more dependent on constant and reliable energy supply Momentary loss of supply may be as costly as a prolonged blackout to a process industry Consumers have become more conscious and demanding and are likely to be even more so into the future Deregulation of the electricity market allows for performance based contracts with stiff penalties for Utilities that don t measure up Slide 41

42 Contacts Details Johan Kristiansson Area Sales Manager Business Development Manager (LSA) ABB AB HV Components Lyviksvägen 4, Ludvika, Sweden Phone: Mobile: Slide 42

43 Disclaimer The information in this document is subject to change without notice and should not be construed as a commitment by ABB. ABB assumes no responsibility for any errors that may appear in this document. In no event shall ABB be liable for direct, indirect, special, incidental or consequential damages of any nature or kind arising from the use of this document, nor shall ABB be liable for incidental or consequential damages arising from use of any software or hardware described in this document. Copyright 2016 ABB. All rights reserved. Slide 43

44