Light Impulse Voltage Generator "S type"
19Pages

HIGH VOLTAGE TEST

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 The SGSA systems can be equipped with hydraulic jacking system or mounted on a trailer for better transportability. The system is built on contains all experience acquired in impulse generator production since 1932. SGSA impulse test systems can be used to generate impulse voltages from 10 kV to 750 kV simulating lightning strokes and switching surges. The total charging voltage range covers from 100 kV to 800 kV with a stage energy of 5 kJ. • total charging voltage from 100 kV up to 800 kV (optional up to 1200 kV) • 5 kJ...

QUALITY USER BENEFITS Quality Compact Design The electronic measurement and control components are designed and manufactured inhouse. Our many years of experience in dealing with electromagnetic compatibility of electronic devices in high voltage test bays provides the requisite expertise. Design of the impulse test system SGSA is light and flexible, for limited space and on-site purposes. For onsite tests it can be easily mounted on a trailer, specially when equipped with hydraulic jacking mechanisms. In designing and manufacturing our impulse test systems we take full advantage of our...

Max. Max charging energy voltage Impulse capacitance SGSA SGSA SGSA SGSA SGSA SGSA SGSA SGSA switching impulse 250/2500 (Option) Max. output voltage at Cb max ± Upeak LI Max. output voltage at Cb max ± Upeak SI Time between impulses at Ul max t s 40 40 40 40 40 40 50 55

Min. safe clearance to wall Capaci- Damping Height tance resistor Shipping volume/ weight (whole system) Impulse Voltage Test System, proposed layout Test specimen

Operating Range Impulse Intervals The minimum output voltage is 10 kV independent of polarity. This is obtained with only one stage. The other stages are shorted or connected in parallel. The maximum output voltage can be read from the table. It depends on the load and the waveform. At maximum charging voltage, minimum time between impulses is given in the table SGSA system data. This interval is dictated by the maximum charging current thermal limitation of parallel resistors and the maximum energy of the impulse capacitors in the impulse generator. If the charging voltage is reduced, the...

T H E I M P U L S E V O LTA G E G E N E R AT O R FUNCTION OF THE IMPULSE TEST SYSTEM The test system comprises 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...

The Impulse Voltage Generator is the main part of an impulse voltage test system. An impulse voltage generator SGS consists of a number of capacitors charged in parallel up to a maximum voltage of 100 kV. When the desired charging voltage has been reached, a set of sphere gaps connect the capacitors in series and the output voltage is delivered via some pulse forming elements. The figure shows an equivalent circuit diagram for a single stage impulse generator (it is possible to simplify a multi stage impulse generator into this circuit). Each impulse capacitor consists of flat elements...

OVERSHOOT C O M P E N S AT I O N Overshoot The most important difference between the simplified equivalent circuit and a more accurate equivalent circuit is the consideration of additional energy storage elements. RS Impulse Capacitance Spark Gap Parallel Resistance Serie Resistance Total Serie Inductance Serie Resistance Load Test Objekt External Overshoot Compensation The consequence of these additional elements is important. Discharge of the impulse capacitor can produce oscillations. If the impulse test circuit forms a resonance circuit an overshoot will be generated. According to IEC...

GLANINGER CIRCUIT Realisation of Overshoot Compensation Realisation of Overshoot Compensation for impulse generators of type SGS is an external additional arrangement of components. This solution can also be used for "Non-Haefely-Generators". Impulse Capacitance Spark Gap Parallel Resistance Serie Resistance/Inductance Overshoot Compensation Test Object, Divider, MAFS (Load) The Glaninger Circuit (see figure below) can be used for testing very small inductances, such as the low-voltage windings of transformers. The Glaninger inductance (LG) is connected in parallel to the series resistor....

CHARGING UNIT LGR 100 Charging rectifiers type LGR 100 are used to charge the capacitive energy storage elements of impulse generators with stages voltages up to 100 kV such as the type SGS. It is usually located close to the base frame of the impulse generator. Connection is with an aluminium tube. The high voltage transformer is resin or oil insulated, rectifier elements and measuring resistors are air insulated. Charging rectifiers of this type are built with castors for greater mobility. Standard charging rectifier type LGR 100 has a rated voltage of 100 kV and a current of 20 mA or 40...

DIVIDERS C S - 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 type CS can also be used as load capacitance for the impulse generator. Oil-filled insulating cylinders accommodate oil paper capacitor packs. Damping resistance for divider type CS is placed externally on top of the uppermost capacitor. Main features:...

Two systems different in sophistication/ technical data are available from Haefely. The well established GC 223 and the fully computerised GC 96. Both control systems for the SGSA test system enable a fully automatic test sequence to be performed. Programming of the control system is user-friendly and easy. A manual mode is also available. Data communication between other Haefely equipment (impulse measuring system) is fully supported. 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...