ENERGY /// TRANSMISSION LINE SURGE ARRESTERS IEC. Bowthorpe EMP Transmission Line Surge Arresters (IEC)

Transcription

1 ENERGY /// TRANSMISSION LINE SURGE ARRESTERS IEC Bowthorpe EMP Transmission Line Surge Arresters (IEC)

2 TRANSMISSION LINE SURGE ARRESTERS Numerous technical publications have stated that lightning is responsible for approximately 65% of all of the non scheduled outages occurring on transmission lines, thus creating many issues for power supply utilities. Power supply utilities themselves have verified the load losses due to voltage sags on their systems from transitory outages caused by lightning activity, and in some regions they have found serious permanent damage caused to the system itself due to these transitory disturbances occurring on important lines. The effect of these transitory disturbances on transmission lines, can also be more critical in areas with high ground resistivity when associated with high lightning activity. Most non-scheduled outages are transitory in nature, with a fault time shorter than 1 minute. In many cases this is still deemed by power supply utilities and their customers, to be unacceptable. This loss of supply is critical for all modern industries now so reliant on sophisticated electronic equipment and especially production processes sensitive to momentary disturbances on the system. In order to reduce the number of non-scheduled outages in electrical systems, power companies and industrial consumers have been studying and promoting improvements to transmission lines thereby increasing their reliability. There are different methods to improve transmission line performance due to lightning: a) Increase the dry arcing distance from the insulators strings. b) Install shield wires on lines without shield wires. c) Improve the shield wire performance. d) Improve the grounding system performance of surges by improving the tower footing resistance. e) Installation of transmission line arresters to counteract the effects of lightning or switching activity. Cases have shown transmission line surge arresters, when electrically connected in parallel with the insulator string, are considered as an effective method to improve transmission line performance, especially when associated with improvements to the grounding system. This will demonstrate a best benefit versus cost relationship in reducing flashovers of the insulator string due to excessive voltages. Once transmission line arresters (TLA) are introduced to a transmission line the voltage is controlled due to the bipolar operation of the Zno elements within the surge arrester. Key Features TLA suspended from a transmission line giving enhanced transmission line performance TLA installed on the tower depending on geometry and clearance Standard IEC for ZnO surge arresters ENERGY /// TRANSMISSION LINE SURGE ARRESTERS IEC

3 UTILITY Utilities are required by statutory demand to increase availability and reliability of transmission systems. Therefore, eliminating operational high cost outages and mandatory penalties is high on the agenda. BENEFITS OF BOWTHORPE EMP TRANSMISSION LINE SURGE ARRESTER INSTALLATIONS Minimizing circuit breaker operation with possible system outage, resulting from back flashover on the shielded transmission line Lightning overvoltages are absorbed over the length of the line, thus reducing the severity of surge at the substation Transmission systems can be operated even where sub-soil gives poor tower footing resistance Eliminating interrupted power supply for sensitive industrial processes Installing transmission line surge arresters on a standard 3 phase voltage system along the line at calculated intervals, allows for optimum performance of the transmission line surge arrester, thus giving increased system line voltage. This eliminates the need to increase the standard insulation level required on conventional system upgrade (typically requires a full system study). APPLICATION Since the late 90 s TE Connectivity (TE) has been supplying transmission line arresters, installed on different transmission line networks around the world. Transmission line arresters are largely being considered as an optimum solution for transmission line reliability, from lightning strikes and back flashovers. Lightning causes back flashovers which cause outages and therefore loss of productivity and potential penalties for the utilities. Suspension clamp Grading ring Silicone rubber insulation Aluminium inter-unit connector Earth cable with strain relief Disconnect device PAGE 3

4 GENERIC TECHNICAL DATA Surge arrester type TLPAA TLPBA TLPCA System voltage U max System voltage U nom Nominal discharge current ka High current impulse (4/10 µs) ka Arrester class designation SL SL SM Repetitive charge transfer rating Q rs C Rated thermal energy W th at U r kj/ Short circuit rating ka Aluminium Fittings Silicone Rubber Housing Qualification testing: Decades of design and development experience have been used to produce today s TE Connectivity transmission line surge arresters. The construction comprises of a number of ZnO elements, assembled within a open cage construction, which has a silicone rubber moulded shed profile chemically bonded to the surface of the core. TE Connectivity transmission line surge arresters are designed and manufactured to the current IEC : 2014 standard and the following tests have been successfully performed. Test performed on metal oxide blocks: Glass Fibre Rods Aluminium Crimp I EC clause Residual Test IEC Clause Long Term Stability Test IEC Clause Charge Transfer Test* IEC Clause Operating Duty test IEC Clause TOV Test IEC Clause Dielectric strength of internal components Test performed on complete surge arresters: ZnO Varistors IEC Clause IEC Clause IEC Clause IEC Clause IEC Clause Cooling Test Short Circuit Tests Bending Moment Tests RIV Tests Weather Ageing Tests Insulation withstand tests on surge arrester housing: Aluminium Heat Sink IEC Clause Dry lightning impulse Wet power frequency Wet switching impulse Insulation tests include *New test introduced in the IEC : 2014 standard. ENERGY /// TRANSMISSION LINE SURGE ARRESTERS IEC

5 ELECTRICAL PERFORMANCE Maximum system voltage U m Rated voltage U r Arrester designation class Long duration current (2000 µs) Nominal discharge current (8/20 µs) Rated short circuit current Rated thermal energy capability (W th ) Arrester type () () (A) (ka) (ka) (kj/) SL TLPAA SL TLPBA SM TLPCA SL TLPAA SL TLPBA SM TLPCA SL TLPAA SL TLPBA SM TLPCA SL TLPAA SL TLPBA SM TLPCA SL TLPAA SL TLPBA SM TLPCA SL TLPAA SL TLPBA SM TLPCA SL TLPAA SL TLPBA SM TLPCA SL TLPAA SL TLPBA SM TLPCA SL TLPBA SM TLPCA SM TLPCA SM TLPCA PAGE 5

6 ELECTRICAL CHARACTERISTICS Maximum Rated Continuous Max. Ures tested with current wave Steep Lightning System U r Operating Switching Current Impulse (30/60 µs) Lightning Current Impulse (8/20 µs) Current Impulse (1/20 µs) U m U c 250 A 500 A 1000 A 2000 A 5 ka 10 ka 20 ka 40 ka 10 ka 20 ka Surge arresters with other characteristics are available on request ENERGY /// TRANSMISSION LINE SURGE ARRESTERS IEC

7 MECHANICAL CHARACTERISTICS TOV Capability impulse Wet power Wet switching Creepage Overall Weight Drawing Product Dry (without prior energy) voltage frequency impulse length length Reference code 1,2/50 µs voltage 250/2500 µs 1 sec* T r 10 sec* T r mm mm Kg BOW TLPAA BOW TLPAA BOW TLPAA BOW TLPAA BOW TLPAA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPCA BOW TLPCA BOW TLPCA BOW TLPCA BOW TLPCA BOW TLPAA BOW TLPAA BOW TLPAA BOW TLPAA BOW TLPAA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPCA BOW TLPCA BOW TLPCA BOW TLPCA2E BOW TLPCA2E-54 * TOV curves are given on technical data sheets for selected surge arrester (on request) PAGE 7

8 ELECTRICAL CHARACTERISTICS Maximum Rated Continuous Max. Ures tested with current wave Steep Lightning System U r Operating Switching Current Impulse (30/60 µs) Lightning Current Impulse (8/20 µs) Current Impulse (1/20 µs) U m U c 250 A 500 A 1000 A 2000 A 5 ka 10 ka 20 ka 40 ka 10 ka 20 ka Surge arresters with other characteristics are available on request ENERGY /// TRANSMISSION LINE SURGE ARRESTERS IEC

9 MECHANICAL CHARACTERISTICS TOV Capability impulse Wet power Wet switching Creepage Overall Weight Drawing Product Dry (without prior energy) voltage - 1,2/50 µs frequency impulse length length Reference code voltage 250/2500 µs 1 sec* T r 10 sec* T r mm mm Kg BOW TLPAA BOW TLPAA BOW TLPAA BOW TLPAA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPCA BOW TLPCA2E BOW TLPCA2E BOW TLPCA2E BOW TLPAA BOW TLPAA BOW TLPAA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPCA2E BOW TLPCA3E BOW TLPCA3E BOW TL2PAA BOW TL2PAA BOW TLPBA BOW TLPBA BOW TLPCA3E BOW TLPCA3E-108 * TOV curves are given on technical data sheets for selected surge arrester (on request) PAGE 9

10 ELECTRICAL CHARACTERISTICS Maximum Rated Continuous Max. Ures tested with current wave Steep Lightning System U r Operating Switching Current Impulse (30/60 µs) Lightning Current Impulse (8/20 µs) Current Impulse (1/20 µs) U m U c 250 A 500 A 1000 A 2000 A 5 ka 10 ka 20 ka 40 ka 10 ka 20 ka Surge arresters with other characteristics are available on request ENERGY /// TRANSMISSION LINE SURGE ARRESTERS IEC

11 MECHANICAL CHARACTERISTICS TOV Capability impulse Wet power Wet switching Creepage Overall Weight Drawing Product Dry (without prior energy) voltage - 1,2/50 µs frequency impulse length length Reference code voltage 250/2500 µs 1 sec* T r 10 sec* T r mm mm Kg BOW TL2PAA BOW TL2PAA BOW TL2PAA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPCA3E BOW TLPCA3E BOW TLPCA31E BOW TL2PAA BOW TL2PAA BOW TL2PAA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPCA3E BOW TLPCA31E BOW TLPCA31E BOW TL3PAA BOW TL3PAA BOW TL3PAA BOW TL3PAA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPCA33E BOW TLPCA33E BOW TLPCA33E BOW TLPCA33E-228 * TOV curves are given on technical data sheets for selected surge arrester (on request) PAGE 11

12 ELECTRICAL CHARACTERISTICS Maximum Rated Continuous Max. Ures tested with current wave Steep Lightning System U r Operating Switching Current Impulse (30/60 µs) Lightning Current Impulse (8/20 µs) Current Impulse (1/20 µs) U m U c 250 A 500 A 1000 A 2000 A 5 ka 10 ka 20 ka 40 ka 10 ka 20 ka Surge arresters with other characteristics are available on request ENERGY /// TRANSMISSION LINE SURGE ARRESTERS IEC

13 CHARACTERISTICS TOV Capability Dry impulse Wet power Wet switching Creepage Overall Weight Drawing Product (without prior energy) voltage frequency impulse length arrester Reference code 1,2/50 µs voltage 250/2500 µs length 1 sec* T r 10 sec* T r mm mm Kg BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPBA BOW TLPCA331E BOW TLPCA331E BOW TLPCA331E BOW TLPCA331E BOW TLPCA332E BOW TLPCA333E BOW TLPCA333E BOW TLPCA333E BOW TLPCA333E BOW TLPCA333E BOW TLPCA3331E BOW TLPCA3333E-444 * TOV curves are given on technical data sheets for selected surge arrester (on request) PAGE 13

14 Line and Earth configurations Clamp Drawing Reference Conductor Range Dia. Palm U Bolt Torque L1 BOW L mm L1 45 Nm L mm L1 45 Nm BOW L mm L6 75 Nm L mm L6 75 Nm L6 BOW L1 / L6 L2 - L5 Strain relief system - E9 TLA surge arrester Braid Suspension clamp assembly Disconnect device Earth connection Line palm Copper shorting braid / cable Strain relief shackle and swivel joint TLA surge arrester Strain relief wire connection Time vs current curve for DD5 disconnect device Time (ms) Current (A) ENERGY /// TRANSMISSION LINE SURGE ARRESTERS IEC

15 Tower installation configuration Tower The number of surge arresters installed on the tower depends on the tower geometry, configuration, and type of tower (suspension or tension) as well as the earthing impedance. Tower Insulators TLA arresters Insulators For towers with a horizontal conductor configuration, normal practice is to install a surge arrester on both of the two outside phase conductors. For towers with a vertical or triangular conductor configuration, the resultant transient voltage across the insulators string sets is usually higher on the bottom phase, which presents a lower distance to the soil and lowest coupling with the shield wire. Therefore, only one surge arrester is necessary on the bottom phase for transmission lines with a vertical configuration and low tower footing impedance. For higher footing impedances it may be necessary to install two or three surge arresters subject to the line analysis. A direct lightning strike to the transmission line without a shield wire will cause discharge current I ( t ) to divide into two current waves travelling in opposite directions along the line with a magnitude of I ( t ) / 2 (it is valid when we consider the impedance of the discharge channel as infinite). This current also produces a voltage wave v (t) in both directions. As a first approach we can consider the transmission line is without losses and distortions, therefore the voltage along the line can be estimated by: V ( t ) = Z 0. i ( t ) /2 (Where Z 0 is the surge impedance) Shield wires on Transmission lines are installed to attract lightning strikes and the voltages will be significantly lower than without shield wires and will depend mainly on the earthing transient behaviour and also the lightning strike point and tower impedance. We are able to carry out a computational study to set where transmission line surge arresters are to be installed for optimum line performance. Consideration to clearances is very important when installing TLA s either on the transmission line or the tower. Another consideration would be the lead length when operation of the disconnect occurs and whether installation of the disconnect is on the phase or the surge arrester earth. A data sheet is available to collate line information. TLA arresters Earth lead PAGE 15

16 Other product ranges available Porcelain surge arresters For system voltages up to 800 Standard: IEC , 2014 and IEEE C62.11: 2012 Designation class: SL, SM and SH High Current short circuit up to 65 ka Application: Transmission and sub-station overvoltage protection Porcelain surge arresters Polymeric surge arresters For system voltages up to 400 Standard: IEC , 2014 and IEEE C62.11:2012 Designation class: SL, SM Short Circuit rating up to 65 ka Application: Transmission and sub-station overvoltage protection Polymeric surge arresters Cable sheath surge arresters For cable sheath protection up to 10 rating Standard: IEC Designation class: DH Application: Cable sheath protection Cable sheath arresters Cable spiker kit Safety device for cables Cable to BS6622 & BS EN/IEC60228 Suitable for cable up to 102 mm diameter Hydraulic pump - no explosive cartridge required Application: To determine if 11 cable is dead or alive Cable spiker kit Airfield lighting box type 2DCAFL4 Suitable for 4 DC lighting systems Standard: IEC , 2014 Designation class: DH Robust design to IP65 Application: Protection of airfield lighting Airfield lighting box ENERGY /// TRANSMISSION LINE SURGE ARRESTERS IEC

17 Brighton High Power Laboratory Impulse generator 1.65 MV 500 power transformer with PD testing High energy surge arrester test system HV varistor block ageing test system with AC and DC supply PAGE 17

18 TE Connectivity (NYSE: TEL) is a $12 billion global technology leader. Our connectivity and sensor solutions are essential in today s increasingly connected world. We collaborate with engineers to transform their concepts into creations redefining what s possible using intelligent, efficient and high-performing TE products and solutions proven in harsh environments. Our 72,000 people, including over 7,000 engineers, partner with customers in close to 150 countries across a wide range of industries. We believe EVERY CONNECTION COUNTS Generation Conventional Power Nuclear Power Wind/Solar Hydro-electric Transmission & Distribution Substation Underground Overhead Street Lighting Industry Mining Petrochemical Railway Shipbuilding WHEREVER ELECTRICITY FLOWS, YOU LL FIND TE ENERGY te.com/energy FOR MORE INFORMATION: hvsa@te.com TE Technical Support Centers AMERICAS USA/Canada: +1 (800) Mexico: Brazil: South America: ASIA-PACIFIC Australia: New Zealand: China: +86 (0) EUROPE-MIDDLE EAST-AFRICA France: +33 (0) Germany/Switzerland: +49 (0) UK: Spain/Portugal: Italy: Benelux: Poland/Baltics: Czech Republic: +42 (0) Sweden/Norway: Middle East: te.com/powertransmission 2016 TE Connectivity Ltd. family of companies. All Rights Reserved. EPP /16 Bowthorpe EMP, TE Connectivity, TE, and the TE connectivity (logo) are trademarks of the TE Connectivity Ltd. family of companies. Other logos, product and/or Company names mentioned herein may be trademarks of their respective owners. While TE has made every reasonable effort to ensure the accuracy of the information in this brochure, TE does not guarantee that it is error-free, nor does TE make any other representation, warranty or guarantee that the information is accurate, correct, reliable or current. TE reserves the right to make any adjustments to the information contained herein at any time without notice. TE expressly disclaims all implied warranties regarding the information contained herein, including, but not limited to, any implied warranties of merchantability or fitness for a particular purpose. The dimensions in this brochure are for reference purposes only and are subject to change without notice. Specifications are subject to change without notice. Consult TE for the latest dimensions and design specifications. ENERGY /// TRANSMISSION LINE SURGE ARRESTERS IEC