ts3_lt8_highvolt_on-site testing of transformers
TRANSCRIPT
HIGHVOLT Prüftechnik Dresden GmbH
Dr. Mario Jochim
SAVE COSTS AND TIME ASSURE QUALITY
On-site testing of transformers
Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH 222
Agenda
§ Motivation
1
1.1
1.2
§ Areas of Application 2
2.1
2.2
2.3
§ Modules of the High Voltage test system
3
§ Induced voltage test
3.1
§ Applied voltage test
3.2
§ Summary
4
Motivation
Ø Mobile test systems are an essential part of quality assurance during manufacturing, repair and diagnostics on-site
Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH 3
§ Saving time and costs by repairing of transformers on-site
§ Essential assembly for large power transformers takes place on-site (Logistical limitations)
§ Diagnostics are being improved
§ Flexible test system use on-site and in the factory
Area of application: On-site repair of transformers
Ø Mobile on-site test systems are necessary to guarantee quality assurance equal to factory testing
Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH 4
§ Transport of faulty transformer to factory is costly and risky
§ Infrastructure limitations (narrow roads, live load of bridges, etc.) do not allow transportation of transformer
§ Prolonged down time/repair time of transformer due to return transportation
§ On-site repair is an attractive alternative (both cost and time-wise) to factory repair
Area of application : Essential assembly for large power transformers on-site § Infrastructure limitations (narrow roads, live load of bridges, etc.) do not allow
transportation of transformer in whole
§ Large transformers are shipped in parts
§ Final assembly has to be performed on-site
Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH 5
Ø Mobile on-site test systems are necessary to guarantee quality assurance equal to factory testing
Area of application : Diagnostics are being improved by HV tests § Improved determination and elimination of interferences due to change of
test frequency
§ Improved failure recognition due to evaluation of partial discharge (PD) inception and extinction voltage by change of the test voltage
§ On-site test results comparable to factory tests
Ø Mobile on-site test systems improve diagnostic value
Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH 6
Area of application : Flexible test system use: on-site and in the factory § Some repair will be performed on-site and some in the factory
§ Mobile test systems increase redundancy, capability and quality comparability and therefore ensure better performance
§ Test results on-site and in the factory needs to be according to the relevant standards
§ Back-up for maintenance, repair and outage of MG-sets
Ø Mobile test systems can be used flexibly on-site and in the factory and save investment cost
Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH 7
Modules of mobile test systems require:
§ Fulfillment of corresponding standards like IEC 60076-3, IEEE C57, GOST 1516.3
§ Compact design for easy transportation worldwide
§ Fast installation and testing
§ Multiple use for fast return on investment
à In short: mobile test systems have comparable functions to stationary test systems but are more compact, robust, assembly friendly, quality focused and multi functional
Ø On-site test results needs to be comparable to results from the factory, R & D
Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH 8
9 Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH
Induced voltage test system on a 40 ft trailer Power: 620 kW, 1.000 kVA for power transformers up to 500 MVA
Space for accessories
Static frequency converter
Step-up transformer
Control room HV filter 1
Power supply cable, HV connection cable
CT’s and VT’s
Space for accessories, HV electrodes, etc.
HV test lead
Ø Compact on-site transformer test system Ø Ready to operate within 1 hour
§ Compact and on-site proven design on: 1 x 40 ft trailer 3 x 20 ft containers
§ Units world wide in service
10 Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH
Induced voltage test system in 3 x 20ft containers Power: 620 kW, 1.000 kVA for power transformers up to 500 MVA
Table: Parameters of the test system
Ø The test system provides results directly comparable to factory test, conformity to corresponding standards
Test System Type WV 620-1200/80
Active power 620 kW
Apparent power 1,000 kVA
Max. output voltage 80 kV
PD level < 50 pC
THD < 5 %
Frequency range 40…200 Hz
11 Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH
TRANSFORMERS TO BE TESTED UP TO APPROX.
Capability of test system for induced voltage test
Test WV 620-1000/80
No-load losses test
350 MVA (500 MVA with THD > 5 %)
Load losses/ short-circuit test 30 MVA
Induced voltage test 500 MVA
Applied voltage tests 46 kV
Ø Essential induced voltage tests can be performed on a large scale on power transformers
Mobile compensation unit (HVCC 24000/36) § Current transformer for high accuracy load
loss measurement § Advanced protection system § Motorized cable drums for easy set-up
(preparation time approx. 1 hour)
12 Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH
Mobile extension for load losses test – HVCC 24000/36
Table: Parameter of HVCC 24000/36
Output terminals
Motorized cable drums
Ø Mobile capacitor bank allows to perform short circuit, load loss and temperature rise test
Extension for load loss testApparent power 24,000 kVAMay. Output voltage 36 kV
13 Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH
THREE POSSIBILITIES OF EXTENSION
How to test bigger transformers?
1 Transformer test system WV 2 HV Capacitor bank HVCC 3 HV Compensation reactor 4 HV Transformer for applied voltage test 5 Transformer to be tested 2nd Transformer test system
Capacitor bank HVCC
Reactor
Ø Even for very large power transformers on-site tests can be arranged
§ Parallel connection of up to 3 units possible
§ Suitable for high active power requirements of the test object
§ Available test power of 1.9 MW/3 MVA (3 systems in parallel)
14 Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH
2nd MOBILE TRANSFORMER TEST SYSTEM
Extension for no-load losses test
Test WV 620-1000/80 with Extension (2nd system in parallel)
No-load losses test 350 MVA (500 MVA with THD > 5 %)
700 MVA (1.000 MVA with THD > 5 %)
Table: Transformers to be tested
15 Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH
TRANSFORMERS TO BE TESTED (UP TO APPROX.)
Mobile extension for load losses test – HVCC 24000/36
Test WV 620-1000/80 with Extension (mobile HVCC 24000/36)
Load losses/short-circuit test 30 MVA 150 MVA
+
Ø Mobile capacitor bank allows to perform short circuit, load loss and temperature rise test
16 Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH
TRANSFORMERS TO BE TESTED (UP TO APPROX.)
Inductive compensation
Test WV 620-1000/80 with Extension (inductive compensation)
Induced voltage test 500 MVA 1000 MVA
+ Compensation reactor
17 Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH
Applied voltage test system
RESONANT SYSTEM WITH VARIABLE FREQUENCY
Wide load range of power transformers 1.3 to 21.5 nF § Variable test frequency 40 to 200 Hz § Test voltage up to 720 kV § Set-up time approx. 1 hour
Ø Test system can also be used for test of GIS and short cables
18 Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH
TRANSFORMERS TO BE TESTED (UP TO APPROX.)
Conclusion
Test WV 620-1000/80 With Extension / second test system
No-load losses test 350 MVA (500 MVA with THD > 5 %)
700 MVA (1.000 MVA with THD > 5 %) (2nd system in parallel)
Load losses/ short-circuit test 30 MVA
150 MVA (mobile HVCC 24000/36)
Induced voltage test 500 MVA 1000 MVA (compensation reactor)
Applied voltage tests 46 kV 300 kV (applied voltage extension) 720kV (WRV system)
Ø Modular structure test system allows cost effective testing even of large power transformers
Summary
§ On-site high voltage tests on transformers are getting more important in the future due to on-site repair, diagnostics, installations and quality conformation
§ Test systems can be used for transformers but for GIS and cables too
§ Due to conformity with standards HV test systems can be used in the factory too
§ Double use in factory and on-site helps to save investment costs
Dr. Mario Jochim, HIGHVOLT PRÜFTECHNIK Dresden GmbH 19
HIGHVOLT Prüftechnik Dresden GmbH HIGHVOLT Prüftechnik Dresden GmbH
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