Analysis of Major Changes to Arrester Standards IEC STEVE BREWER

Transcription

1 Analysis of Major Changes to Arrester Standards IEC STEVE BREWER

2 Analysis of Major Changes to Arrester Standard IEC Steve Brewer- Senior Product Manager - HPS Arrester Business Unit

3 Agenda Fundamental Differences between IEC Edition 2.2 and Edition 3.0 Arrester Classification Arrester Type Tests Repetitive Charge Transfer Operating Duty Power-frequency voltage versus time Arrester disconnector / fault indicator Weather ageing test polymer

4 Edition 3.0 Edition 2.2 IEC Arrester Classifications Standard nominal discharge current A A A A Rated Voltage U r (kv rms) 360 < U r < < U r < 360 U r 132 U r 36 Arrester Class Station Distribution Designation SH SM SL DH DM DL Nominal discharge current 20 ka 10 ka 10 ka 10 ka 5 ka 2.5 ka Switching impulse discharge current 2 ka 1 ka 0.5 ka Qrs (Coulombs) Wth (kj/kv of Rated Voltage) Qth (Coulombs) MAIN CHANGES Classifications now more associated with application Now 6 classes instead of 4, more finely divided according to expected duty Addition of the definitions for distribution and substation

5 Edition 3.0 IEC Arrester Classifications Arrester Class Station Distribution Designation SH SM SL DH DM DL Nominal discharge current 20 ka 10 ka 10 ka 10 ka 5 ka 2.5 ka Switching impulse discharge current 2 ka 1 ka 0.5 ka Qrs (Coulombs) Wth (kj/kv of Rated Voltage) Qth (Coulombs) Distribution Class Arrester intended for use on distribution systems to protect components primarily from the effects of lightning. Station Class Arrester intended for use in stations to protect the equipment from transient over-voltages.

6 Edition 3.0 IEC Arrester Classifications Arrester Class Station Distribution Designation SH SM SL DH DM DL Nominal discharge current 20 ka 10 ka 10 ka 10 ka 5 ka 2.5 ka Switching impulse discharge current 2 ka 1 ka 0.5 ka Qrs (Coulombs) Wth (kj/kv of Rated Voltage) Qth (Coulombs) Sub-classifications within each class there are designations relating to the duty that the arrester will experience as noted below. SH = Station High duty SM = Station Medium duty SL = Station Low duty DH = Distribution High duty DM = Distribution Medium duty DL = Distribution Low duty

7 Edition Insulation withstand tests on the arrester housing a) Lightning impulse b) Switching impulse c) Power-frequency 2 Residual voltage test a) Steep current b) Lightning impulse c) Switching impulse 3 Long-duration current impulse withstand test 4 Operating duty test a) High-current impulse operating duty b) Switching surge operating duty test 5 Short circuit 6 Arrester disconnector / fault indicator (when fitted) 7 Polluted housing test 8 Internal partial discharge test 9 Bending moment 10 Environmental tests 11 Seal leak rate 12 Radio interference voltage (RIV) 13 Weather ageing test - polymer Note: Section 6.10 required Power-frequency voltage versus time characteristics to be measured with prior duty only. IEC Arrester Type Tests Edition Insulation withstand tests on the arrester housing a) Lightning impulse b) Switching impulse c) Power-frequency 2 Residual voltage test a) Steep current b) Lightning impulse c) Switching impulse 3 Test to verify long term stability under continuous operating voltage 4 Repetitive charge transfer withstand 5 Heat dissipation behaviour verification of test sample 6 Operating duty test 7 Power-frequency voltage versus time 8 Arrester disconnector / fault indicator (when fitted) 9 Short-circuit tests 10 Bending moment 11 Environmental tests 12 Seal leak rate 13 Radio interference voltage (RIV) 14 Test to verify the dielectric withstand of the internal components of an arrester 15 Test of internal grading components 16 Polluted housing test 17 Weather ageing test polymer

8 Edition Insulation withstand tests on the arrester housing a) Lightning impulse b) Switching impulse c) Power-frequency 2 Residual voltage test a) Steep current b) Lightning impulse c) Switching impulse 3 Long-duration current impulse withstand test 4 Operating duty test a) High-current impulse operating duty b) Switching surge operating duty test 5 Short circuit 6 Arrester disconnector / fault indicator (when fitted) 7 Polluted housing test 8 Internal partial discharge test 9 Bending moment 10 Environmental tests 11 Seal leak rate 12 Radio interference voltage (RIV) 13 Weather ageing test - polymer Note: Section 6.10 required Power-frequency voltage versus time characteristics to be measured with prior duty only. IEC Arrester Type Tests Removed Edition Insulation withstand tests on the arrester housing a) Lightning impulse b) Switching impulse c) Power-frequency 2 Residual voltage test a) Steep current b) Lightning impulse c) Switching impulse 3 Test to verify long term stability under continuous operating voltage 4 Repetitive charge transfer withstand 5 Heat dissipation behaviour verification of test sample 6 Operating duty test 7 Power-frequency voltage versus time 8 Arrester disconnector / fault indicator (when fitted) 9 Short-circuit tests 10 Bending moment 11 Environmental tests 12 Seal leak rate 13 Radio interference voltage (RIV) 14 Test to verify the dielectric withstand of the internal components of an arrester 15 Test of internal grading components 16 Polluted housing test 17 Weather ageing test polymer Formerly part of Operating Duty Test Legend Significant Addition Significant Change Unchanged or Minor Minor Addition

9 Edition 3.0 (8.4) Test to verify long term MOV stability with U c applied CHANGES In Edition 2.2 there was no pass / fail criteria. P end could be any value as related to P start. A penalty factor was imposed on later testing based on the ratio - P end /P start 1000 Hr Power Loss EDITION EVALUATION Test considered passed if all three samples behave as follows: After P min established any increase is not greater than 1.3 x P min P end 1.3 x P start

10 Power Loss (Watts) MOV Aging Test Example Time (Hours)

11 Edition 2.2 (8.4) Long-duration current impulse withstand test X μsec 3 arresters samples required 6 groups of 3 impulses to each sample seconds between impulses Cool samples to ambient between groups EVALUATION No physical damage is evident (puncture, flashover, cracking) Measure residual EVALUATION voltage before and after test sequence - Discharge voltage shall not change more than 5% from initial measurements Impulse Close-up View Duration (X) LDC μsec LDC μsec LDC μsec LDC μsec LDC μsec

12 Edition 3.0 (8.5) Repetitive charge transfer rating test - Q rs 10 Samples minimum required 10 groups of 2 impulses to each sample seconds between impulses Cool samples to ambient between groups Charge levels shall equal the claimed value multiplied by 1.1 Waveshape selection Station class rect. (2-4ms) Distribution class 8/20 Claimable charge ratings Q rs 0.1 C to 1.2 C in steps of 0.1 C 1.2 C to 4.4 C in steps of 0.4 C 4.4 C to 10 C in steps of 0.8 C 10 C to 20 C in steps of 2 C 20 C up in steps of 4 C EVALUATION No physical damage is evident (puncture, flashover, cracking) Measure Residual Voltage before and after testing - shall not change more than 5% Measure Reference Voltage before and after testing - shall not change more than 5%

13 Edition 2.2 (8.5) Operating Duty Tests MOV Pre-conditioning Three samples 4 groups of 5 impulses at nominal discharge current seconds between impulses Interval between groups: min During the impulses the MOVs are energized at 1.2 X U c

14 Preheat to 60 C Edition 2.2 (8.5.4) High Current Impulse Operating Duty Test For Class 1 arresters and below (5kA, 2.5kA) Amplitude per table below 10 sec 30 minutes U r U c Arrester Classification 10kA 5kA 2.5kA Peak 4/10 current 100kA 65kA 25kA Apply 1 st 4/10 impulse, Preheat to 60 C, Apply 2 nd 4/10 impulse Less than 100msec after 2 nd impulse apply U r for 10 seconds Within 1 second after the overvoltage apply U c for 30 minutes Measure temperature, resistive component of current or watts loss for 30 minutes to demonstrate thermal stability

15 Preheat to 60 C Edition 2.2 (8.5.5) Switching Surge Operating Duty Test For Class 2 arresters and above 100kA 4/10 impulses Duration and Amplitude matches Long Duration Impulse Test 10 sec 30 minutes U r U c Apply 2 x 4/10 impulses, Preheat to 60 C, Apply 2 x LD impulses sec apart Less than 100msec after 2 nd impulse apply U r for 10 seconds Within 1 second after the overvoltage apply U c for 30 minutes Measure temperature, resistive component of current or watts loss for 30 minutes to demonstrate thermal stability

16 Cool to Ambient Edition 3.0 (8.7) Operating Duty Tests MOV Pre-conditioning For Distribution Class Arresters 4/10 Current Impulse amplitude requirements For Station Class Arresters Arrester Nominal Discharge Current (I n ) 20kA and 10kA 5kA 2.5kA Peak 4/10 current 100kA 65kA 25kA

17 Edition 3.0 (8.7) Operating Duty Tests Q th Injection - Distribution Preheat to 60 C 10 sec 30 minutes U r U c 1 min Distribution Class Arresters Two x 8/20 current impulses within one minute Arrester Classification Qth Rating (Coulombs) Qth per Impulse (Coulombs) Corresponding 8/20 current amplitude DH 10kA kA DM 5kA kA DL 2.5kA kA

18 Preheat to 60 C Edition 3.0 (8.7) Operating Duty Tests W th Injection - Station Showing 2 but could be any number 10 sec 30 minutes U r U c 3 MIN Station Class Arresters One or more long duration impulses (2-4 msec duration) within 3 minutes provided the accumulated energy is at least equal to a claimable thermal energy rating W th. W th Units: kj / kv of U r Claimable W th Values: 1 to 5 steps of to 16 steps of 1 16 to 30 steps of 2 30 and up steps of 6

19 Preheat to 60 C Edition 3.0 (8.8) Power-frequency (TOV) Voltage Versus Time Test Station rectangular waves shown. If DH these would be 8/20 Duration per Chart U c for 30 minutes This voltage is what is plotted Prior Duty Test requires injection of Q th or W th energy exactly like operating duty test. Four tests, One in each range = 4 data points. Without Prior Duty Test has no impulses prior to start of TOV time period. Two tests, One from two ranges = 2 data points TOV Required Time Ranges (Seconds) Range to 1.0 Range to 10 Range to 100 Range to 3,600

20 Edition 2.2 (8.6) Arrester Disconnector Tests Withstand without operating: Long-duration current impulse test Operating duty test Time versus current curve test 20A, 200A, 800A Edition 3.0 (8.9) Arrester Disconnector Tests Withstand without operating: Repetitive Charge transfer test - Q rs Operating duty test W th or Q th Time versus current curve test 20A, 200A, 800A Bending moment, tensile load and torsional load tests Temperature cycling and seal pumping tests Added

21 Edition 2.2 ( ) Weather Ageing test for Polymer Housed Arresters 1000 hour salt fog at U c NaCl concentration between 1 and 10 kg/m 3 If requested by the user and agreed to by the manufacturer 5000 hour multi-stress test UV, rain, dry heat, damp heat, high humidity, salt fog Removed } Edition 3.0 ( ) Weather Ageing test for Polymer Housed Arresters 1000 hour salt fog at U c NaCl concentration between 1 and 10 kg/m hour UV light test of the housing materials Added

22 Basic differences between Edition 2.2 and Edition 3.0 Line Discharge Classes eliminated Q rs is a test of the MOV durability only claimable charge rating comes from this test Operating Duty test determines arrester s 2 shot capability WITH subsequent thermal recovery. Station = W th = actual measurement in kj/kv of Ur Distribution = Q th = compliance to DL,DM or DH charge transfer levels (.45C, 0.7C, 1.1C) TOV test is more standardized and required both prior duty and without prior duty Disconnector testing expanded to include mechanical and seal testing. For polymer arresters the Weather Ageing test has been modified 5000 hour multi-stress test option removed, UV test requirement added.