LL Sgda
LL Sgda
LL Sgda
SG A
I M P U L S E V O LTA G E T E S T S Y S T E M SG A 2 0 0 -2 6 0 0 k V, 1 0 - 2 6 0 k J
I M P U L S E V O LTA G E T E S T S Y S T E M
A P P L I C AT I O N
SG A impulse test systems are used to generate impulse voltages from 10 kV to 2400 kV simulating lightning strokes and switching surges. The total charging voltage range covers from 600 kV to 2600 kV with a stage energy of 5 or 10 kJ. Haefelys system design and manufacture is based upon years of experience dating back to 1932. The SG generators are flexible and cover testing applications according to IEC, ANSI/IEEE as well as other national standards. The basic system can be upgraded in various ways for special tests and / or greater ease of operation. A number of additional circuits and components allow to optimise the impulse test system for tests on: power transformers cables (type tests) arresters (impulse current tests) motor / generators insulators bushings GIS instrument transformers The user-friendly control unit can also be remotely operated from a host computer. Due to its unique Haefely -structure, the SG impulse generator are perfectly suited for transportation and on-site erection.
SG A
QUALITY
USER BENEFITS
Quality
Haefely Test AG quality assurance complies with DIN ISO 9001. Design and manufacturing of our impulse test systems take full advantage of seven decades of experience in high voltage test technology. Electronic measurement and control systems are designed and manufactured in-house. We have many years of experience with EMC testing as well as an excellent reputation in the field of high voltage test products. As a result, we achieve high reliability at a favourable price performance ratio.
Safety of Operation
The design of the test system and, in particular, the control system comply with VDE 0104. Testing personnel benefit from optimal protection against accidents. Especially the newly designed grounding system which is unique. This system, guarantees safe operation under any circumstances, and is automatically activated during a power outage. As always safe operation of a HV test system does require proper personnel training.
Appearance
High voltage testing is an important part of the manufacturing process which finally ensures the quality of your products. A well-equipped test hall with appropriate appearance is therefore important. Haefely products are not only technically but also aesthetically designed to complement the quality image of your facilities.
Grounding Device
G E N E R A L S Y S T E M S P E C I F I C AT I O N S
S G A S Y S T E M D ATA ( 5 k J p e r s t a g e )
Generator lightning impulse 1.2/50 switching impulse 250/2500 (Option)
Code
Max. load
SG A
Cs nF
167 143 125 100 83 71 62.5 55.5 50 45.5 41.7 38.5
Cb max LI nF
6.2 5.6 5.3 5.7 4.7 4.0 3.4 3.0 2.6 2.4 2.1 1.9
Max. load
Cb max SI nF
1.7 1.7 2.3 1.9 1.8 3.5 3.0 2.7 2.7 2.5 1.7 1.9
SG SG SG SG SG SG SG SG SG SG SG SG
A A A A A A A A A A A A
600-30 700-35 800-40 1000-50 1200-60 1400-70 1600-80 1800-90 2000-100 2200-110 2400-120 2600-130
600 700 800 1000 1200 1400 1600 1800 2000 2200 2400 2600
Divider Code Capaci- Damping Height tance resistor Weight (net) Shipping volume/ weight (whole system)
W m
1.2 1.4 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.2
H1 m
3.4 3.7 4.1 4.8 5.5 6.2 6.9 7.7 8.4 9.1 9.8 10.6
C kg
1300 1375 1460 1650 1850 2000 2200 2350 2500 2700 2850 3050 CS 600-500 CS 700-500 CS 800-670 CS 1000-670 CR 1200-700 CR 1400-525 CR 1600-525 CR 1800-420 CR 2000-420 CR 2200-350 CR 2400-350 CR 2600-300
R
270 270 230 230 180 240 240 300 300 360 360 420
H2 m
2.3 2.4 3.6 3.6 3.7 5.5 5.5 6.8 6.8 7.8 7.8 8.9
pF
500 500 670 670 700 525 525 420 420 350 350 300
kg
110 110 135 135 360 450 450 620 620 670 670 750
m3/kg
approx. 6 m3 + 1 m3/stage approx. 150% of net weights
min 1.8 m
2.0 m
G E N E R A L S Y S T E M S P E C I F I C AT I O N S
S G A S Y S T E M D ATA ( 1 0 k J p e r s t a g e )
Generator lightning impulse 1.2/50 switching impulse 250/2500 (Option)
Code
Max. load
SG A
Cs nF
367 286 250 200 167 143 125 111 100 91 83 77
Cb max LI nF
6.0 5.4 5.1 5.5 4.5 3.8 3.3 2.9 2.5 2.3 2.0 1.8
Max. load
Cb max SI nF
1.6 1.6 2.2 1.8 1.7 2.1 1.8 1.8 2.2 1.6 1.6 1.7
SG SG SG SG SG SG SG SG SG SG SG SG
A A A A A A A A A A A A
600-60 700-70 800-80 1000-100 1200-120 1400-140 1600-160 1800-180 2000-200 2200-220 2400-240 2600-260
600 700 800 1000 1200 1400 1600 1800 2000 2200 2400 2600
Clearances and divider types are the same as for 5 kJ per stage generator
Operating Range
The minimum output voltage is 10 kV independent of polarity. This is obtained with only one stage operating. The other stages are shorted or connected in parallel. Maximum output voltage can be read from the table on page 6. It depends on the load and the waveform. The chart shows the influence of front resistor values regarding front time T1 and load capacitance Cb. The calculation is made for an impulse generator type 1200-60 for lightning impulse. Each resistor covers a part of the load range for a front time according standard.
Impulse Intervals
At maximum charging voltage, minimum time between impulses is specified in the table system data. This interval is dictated by the maximum charging current and the maximum energy of the impulse capacitors as well as the thermal behaviour of the resistors. If the charging voltage is reduced, the interval between impulses can be shortened.
Ambient Conditions
The impulse generator can be operated at ambient temperatures between 3C and 45C and relative humidity (r.h.) 95% (non condensing). The control and measurement equipment is designed for operation at ambient temperatures of 10C to 45C and r.h. values between 35% and 80%. The permissible temperature and r.h. ranges for shipping and storage of all parts are -20C to 60C and 95% r.h. (non condensing). The voltage values stated in the documentation are for standard conditions, T = 20C, p = 1013 hPa and r.h. = 80%. These values apply for operation of the system up to 1000 m above sea level. For higher elevations, the voltage reduces by 1% for each add. 100 m.
T H E I M P U L S E V O LTA G E S Y S T E M
FUNCTION OF THE IMPULSE TEST SYSTEM
As shown in the block diagramm below the test system has the following main components: charging rectifier impulse generator control system divider Accessories for additional measurements, tests or analyses of the wave shape are: shunt chopping gap measuring system The block diagram below demonstrates the basic functions of the system. The impulse test system operates under a control system which charges the impulse generator through the charging unit. This is achieved as the stages in the impulse generator are connected in parallel via the charging resistors. Charging time and charging voltage can be selected. Once the selected charging voltage has been reached, a trigger pulse initiates firing of the first spark-gap of the impulse generator. The resulting overvoltages trigger successive stages. As all the spark-gaps fire, the stages are connected in series thus multiplying the charging voltage. An impulse voltage divider reduces the impulse voltage to a value that the measuring and recording instruments require.
SG A
Charging Rectifier
Impulse Generator
Divider
Shunt
mm
Accessories
I M P U L S E G E N E R AT O R
SF RS
The Impulse Voltage Generator is the main part of an impulse voltage test system. An impulse voltage generator SG is a number of capacitors charged in parallel up to a maximum voltage of 100 kV. When the final charging voltage is reached, the encapsulated sphere gaps are fired and connect the capacitors in series. Wave shape of the generated impulse is mainly defined by serial and parallel resistors. The figure shows a simplified equivalent circuit diagram of a one stage impulse generator.
CS
RP
CL
CS SF RP RS CL
Impulse Capacitance Spark Gap Parallel Resistance Series Resistance Load Test Object
DESIGN
Like all Haefely impulse generators the SG generator is based on the MARX multiplier circuit. Standard impulse generators type SG are equipped with castors for mobility or without castors for stationary operation. Optionally we offer air cushions for easiest moving of very large systems. The sophisticated design of this impulse test system considers all requirements in conjunction with impulse voltage tests as required by industry (HV- Cable, HV- Power- Transformers, etc.) and universities respectively utilities.
Haefely
Structure
The new unique Haefely -Structure (pat. pending) is easy to transport and reassemble, due to its modular design. The sturdiness of the design makes it ideal for on-site testing. Modules of 2 and 3 stages can be combined to any total number of stages between 4 and 26. As shown in the picture below the area enclosed by the inductance loop has been reduced to the minimum (a ) which results in minimal inductance in the impulse generator circuit. This has a positive effect on the overall load range, the triggering and the rise times. In order to increase the impulse capacitance, the generator
stages can be grouped and connected in parallel. For larger generators several identical groups can again be connected in series. The total voltage is the product of the stage charging voltage and the number of groups in series. All possible combinations cover requirements for a variety of test loads.
- structure
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T H E I M P U L S E V O LTA G E G E N E R AT O R
Impulse capacitors
Each impulse capacitor consists of flat elements built into a steel housing and impregnated with castor oil. The housing walls are flexible so that the oil can expand. Years of experience with castor oil guarantee a long capacitor life.
SG A
10
Resistors
Wave shaping resistors built into the impulse generator are wire wound on tubes and protected with shrink tubing against mechanical damage. Each resistor value has a specific colour for easy identification.
These resistors are handy plug-in types for easy and quick reconfiguration. The total number of plug-in positions for serial and parallel resistors is four. This allows more variation possibilities and, due to twin resistors, higher energies and shorter times between impulses. External series resistors are only required for generators up to 12 stages. The basic system includes a set of resistors for lightning impulse voltages.
OPTIONS
H A E F E LY S A F E T Y GROUNDING SYSTEM
The new Haefely safety grounding system consists of 3 direct drives and 3 spring loaded reels. No complex gear boxes , no redirection wheels and no adjustments are required which greatly improves reliability. As safety issues are always important, Haefely has developed a safety grounding system which works automatically at power outages. The new Haefely safety grounding system, which is standard for all SG A Generators, provides optimal protection for your operating staff.
Parallel resistors
In order to compensate for the shorter decay time with small inductances, an additional set of parallel resistors can be supplied. It consists of additionel two resistors per stage.
Shunts
Haefely shunts are used for the measurement of impulse currents. They consist of a metal cylinder with coupling flanges and coaxial measuring connector. Different sets of shunts are available.
System grounded
spring loaded reels
System operating
Spring loaded reels
Top Electrodes
Direct drive units Insulating band conducting band
Direct drive units
All SG A generators are equipped with a large rounded top plate sufficient for many applications. For higher voltages and switching impulses additional top electrodes might be required. The SG A generator is prepared for various top electrode solutions. The top plate allows also mounting of large state electrodes.
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O V E R S H O O T C O M P E N S AT I O N
Application
The patented Haefely Overshoot Compensation is used for lightning impulse voltage tests on high capacitive loads, low inductive loads and impulse test with steep front impulse shapes. Overshoot compensation can be of assistance during dielectric tests of the following equipment:
Overshoot Compensation
The Haefely Patented Overshoot Compensation consists of a compensating capacitor (CC), a compensating resistor (RC) and an inductance (LC). This circuit together with the load capacitance Cb forms a first order low pass filter (see diagram below). The high frequencies of an oscillation are damped. Therefore an overshoot can be eliminated or damped.
SG A
1. Distribution and Power Transformers (high capacitance / low inductance) 2. Motors / Generators (steep front) 3. Switchgear / Gas insulated Switchgear (high capacitance) 4. Bushings (high capacitance) Overshoot Test objects are not pure capacitive loads. A realistic impulse voltage test circuit can be described by the following diagram:
SF CS RP RS LS CL
SF CS RP
RS
LS
CC CL
RC
LC
Impulse Capacitance Spark Gap Parallel Resistance Serie Resistance/Inductance Overshoot Compensation Test Object, Divider, MAFS (Load)
CS SF RP RS, LS CL
Impulse Capacitance Spark Gap Parallel Resistance Series Resistance/Inductance Test Object, Divider, MAFS (Load)
In the following figure the uncompensated voltage (black curve), the voltage across the overshoot compensation (red curve) and the resulting voltage across the test object (blue curve) are shown. The final voltage across the test object is now according to the standard.
Compared to a circuit with pure capacitive load (CL) the real test object (RL, CL and LL) often creates wave shapes with significant oscillation / overshoot. IEC 60060-1 specifies a maximum of 5% overshoot for lightning impulses.
U X
Definition: Overshoot
Upeak
5%
As inductance of the test circuit cannot be reduced (physical laws apply), an additional circuit, the Haefely patented Overshoot Compensation, control can be used to this.
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GLANINGER CIRCUIT
Glaninger
The Glaninger Circuit (see diagram below) can be used for testing very small inductances, such as low-voltage windings of transformers. The Glaninger inductance (LG) is connected in parallel to the generator serial resistor. The rapid rise at the impulse front (high frequency components) is not influenced by the additional Glaninger inductance LG, therefore the front of the impulse is mainly defined by the serial resistor. Conversely, the slow decay (low frequency components) at the tail of the impulse is influenced by the parallel connection of LG and RS. The result is less damping in the overall test circuit and an increased time to half value.
LG SF CS
External Overshoot Compensation
RS RP
LS RD RL CL LL
CS SF RP RS,LS LG RD
Impulse Capacitance Spark Gap Parallel Resistance Series Resistance/Inductance Glaninger Inductance Damping Resistor (only if LS < 10 LG) RL, CL, LL Test Object, Divider, MAFS (Load)
Design
An external design for the SG is available. This solution can also be used for Non HaefelyGenerators.
13
Charging rectifiers type LGR 100 are used to charge the capacitive storage elements of an impulse generator with stage voltages up to 100 kV such as the generator type SG . It is usually located close to the base frame of the impulse generator. Connection to the impulse generator is by an aluminium tube. The high voltage transformer is resin or oil insulated, and the rectifier element and measuring resistor are air insulated. Normally charging rectifiers of this type have castors for mobility. Standard charging rectifier type LGR 100 has a rated voltage of 100 kV and a current of 20 mA (LGR 100-20) or 40 mA (LGR 100-40). For generators with more than 12 stages we recommend the 40 mA version. Main features of the LGR 100 are: compact design short circuit protected standard automatic motor-driven polarity reversal for LGR 100-40 optional automatic motor-driven polarity reversal for LGR 100-20
SG A
LGR 100-40
LGR 100-20
LGR 100-20 Rated voltage Un, both polarities Rated current at Un, continuous duty Circuit Reversal time for polarity motor drive Test voltage, 5 minutes, both polarities Ambient temperature Measuring resistor Supply voltage (standard) 3P + N Power consumption Input power three phase (also valid for matching transformer design) Weight (approx.) net gross Shipping volume 100 kV 20 mA voltage doubling circuit approx. 30 s 110 kV 0C...+45 C 100 kV, approx. 200 M 3x400 V, 50/60 Hz 4 kVA 10 kVA 165 kg 240 kg 1.5 m3
LGR 100-40 100 kV 40 mA single-phase one-way circuit approx. 30 s 110 kV 0C...+45 C 100 kV, approx. 200 M 3x400 V, 50/60 Hz 10 kVA 22 kVA 540 kg 700 kg 2.5 m3
(For earth trip breaker protected supply voltages matching transformer required)
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DIVIDERS
C S / C R - D A M P E D C A PA C I T I V E I M P U L S E V O LTA G E D I V I D E R
Damped capacitive impulse voltage dividers are used to measure high voltage full and tail chopped lightning and full switching impulses. Provided with an adequate additional secondary part they can also be used for alternating voltage measurements. Dividers of type CS and CR also represent a basic load capacitance for the impulse generator. Insulating cylinders house oil/paper capacitor packs. Damping resistors for dividers of type CS are placed externally on top of the uppermost capacitor. Dividers of type CR have an internal distributed resistance and, for higher voltages, an external damping resistance.
Main features:
response of system meets the requirements of IEC 6006-2 (1994) stable four arms mobile base frame indoor and outdoor types available different top-electrodes available depending of switching impulse requirements
CR-3200-263
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CONTROLS
Two control systems different in sophistication/ technical data are available from Haefely. The competitive and well established GC 223 and the fully computerised GC 96 IMP. Control systems for the SG A test system allow creation of fully automatic test sequences. Programming of the control system is user-friendly and easy. A manual mode is also available. Data communication between other Haefely equipment (impulse measuring equipment) is fully supported. So the control system determines automatically the efficiency factor of the impulse test system in a specific test configuration from the measured impulse amplitude of a single pulse. For all following shots, the charging voltage is automatically controlled in such a way, that a preset output voltage is met exactly .Remote control from a host computer is also available. The control system can be designed as a desk, a mini rack or an integrated version. Haefely control systems are based on an in-house design of PCI (special computer based on the latest P.C.). No additional measures such as optical link or IR communications are necessary.
SG A
OPTIONS
Control Desk
The control unit GC 96 IMP can be mounted in different desk or console versions. Unused space in the control desk can be used for other measurement instruments, such as the Haefely HiAS, DiAS or DMI.
GC 96 IMP Interface
With a GC 96 IMP serial interface, the test system can be controlled by a higher-level computer. The interface is optically isolated, so that electromagnetic compatibility standards (IEC 61000-4-2) are completely fulfilled.
16
SPECIAL SOLUTIONS
Mobility
The basic version of the SG is equipped with a rigid base frame and large castors. As an option we offer air cushions.
On-site testing
Due to the new modular Haefely -Structure (pat. pending) assembly of the generator is performed extremely fast. A 2000 kV generator consists of 6 modules, base and topframe. To set up such a system : the modules have to be placed on top of each other a few resistors and drive shafts have to be plugged in the three grounding bands must be mounted These tasks can be performed much faster than for any other generator currently available. All Haefely SG generators are based on this new structure enabling easy erection as well as upgrading.
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O S C I L L AT I N G I M P U L S E T E S T S Y S T E M
SG A
Inductance
Specification SG A-L
Oscillating lightning impulse-OLI Code Load without divider nF Number Peak value Rise time of (kV) T1 (s) inductance modules 2nF 20nF 2nF 20nF 3 4 7 1000 1400 3100 800 1150 2200 5 5 5 12 13 13 Oscillating switching impulse -OSI Number Peak value of (kV) inductance modules 2nF 20nF 3 4 5 950 1350 2800 750 1000 1900 Peak time Td (s) 2nF 140 150 160 20nF 350 360 400 CSL 1200 CSL 1500 CR 3200 L 11 14 26 W 8 11 20 H 7 9 18 Divider Dimension of test location
Impulse Current
Theoretically only different resistors and wave shaping inductances are required for the generation of impulse currents. In practice it is necessary to know the required wave shape, the relevant standard, the residual voltage (in the case of arrestor testing) and the maximum load capacitance. With this information a possible extension of an impulse voltage generator to an impulse current generator can be estimated. For lightning impulse current 8/20 s according IEC 60060-1 and 60099-4 an extension is usually possible.
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Technical Services
A high level of customer service is essential in view of the complexity of high voltage test systems and the high reliability demanded by the customer. The full warranty of the impulse voltage test system is conditional on the performance of the following Haefely services being performed: Expert installation and on-site testing of the system Training of the operating personnel Maintenance of the test system throughout its service life, but for a period of at least 10 years Availability of spare parts at least for 10 years
After acceptance testing, the personnel assigned to operate the impulse voltage test system will be trained. Installation and operator training are conducted by Haefely customer service personnel and are adapted to suit the particular test facility and test specimen. This is an important contribution to reliable operation of the test system.
Other Services
Haefely offers a maintenance agreement tailored to the customers special needs. In this way, the value of the test system can be preserved over a long period of time. Further services are offered for support in integration tasks or during operation.
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S C O P E O F S U P P LY
SG A
1 Impulse generator 1.2/50 s, including: Mobile base frame Enclosed spark gaps Motor driven safety grounding system 1 Set resistors for lightning impulse 1 Charging rectifier, 100 kV, 20 mA with manual polarity change or 40 mA with automatic polarity change for generator with 10 kJ per stage 1 Control unit GC 223 2 Control cables, each 20 m 1 Impulse voltage divider CS ___ or CR___mobile 1 Secondary unit 1 Measuring cable, 20 m 1 Grounding rod with grounding wire, 5 m 1 Copper grounding band, 30 m 2 Set of operating instructions with test report (in English or German) 1 Technical service (upon request) Installation and testing on site Training of operating personnel
Options
Sphere gap KFS Multiple chopping gap MAFS Set resistors for switching impulse SG SW Set resistors for testing of small inductance SG RP Glaninger circuit for very small inductance SG WI Set of terminal resistors for winding transformers tests SG TERM Charging rectifier 100 kV, 40 mA LGR 100-40, instead of LGR 100-20 Motor drive for polarity reversal LGR POL (for 20 mA LGR only) Insulating and matching transformer SG TRANS Overshoot Compensation for high capacitive loads SG OC Set of spare parts SG ERS consisting of: - impulse Capacitor - resistor of each value and type - trigger electrode for spark-gap
E117.10 Haefely Test AG High Voltage Test Division Lehenmattstrasse 353. P.O. Box CH-4052 Basel Switzerland Phone: +41.61. 373 41 11 Fax: +41.61. 373 49 12 e-mail: sales@haefely.com
Subject to change without prior notice 09.2001
www.haefely.com
SG A