Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
  • G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
  • G01R31/14—Circuits therefor, e.g. for generating test voltages, sensing circuits
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
  • H01T4/00—Overvoltage arresters using spark gaps
  • H01T4/16—Overvoltage arresters using spark gaps having a plurality of gaps arranged in series
  • H01T4/20—Arrangements for improving potential distribution
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
  • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
  • H03K3/53—Generators characterised by the type of circuit or by the means used for producing pulses by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback
  • H03K3/537—Generators characterised by the type of circuit or by the means used for producing pulses by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback the switching device being a spark gap

Definitions

• the present invention relates to a clipping spark gap for a high voltage pulse testing system, preferably for quality assurance of power transformers.
• the purpose of the high-voltage test is to simulate transient overvoltages in three-phase networks by means of artificially generated pulsed surges.
• Classically a distinction is made between external overvoltages, which are caused, for example, by a lightning strike, and internal circuit overvoltages, which arise as a result of switching operations in the network.
• the multitude of overvoltage phenomena are reduced to standardized lightning and switching impulse voltages for testing purposes.
• parameters are defined which describe the increase of the voltage, the peak value and the back drop within certain tolerances.
• the cut lightning impulse which is to simulate the effect of very fast voltage changes, is added as a further parameter, the cut-off time.
• the requirements, voltage forms as well as the determination of these parameters are defined in the ICE 60060-1.
• the high-voltage pulse testing system includes a pulse generator and auxiliary components such as a cut-off spark gap, a voltage divider and overshoot compensation.
• Marx 's multiplication circuits also called Marx generators
• the circuit type is constructed in a plurality of circuit stages, each of the stages connected in series having a surge capacitance and a switching device, in particular a switching spark gap, and a shunt capacitor and switching element in parallel Resistor and this connected in series has a resistor.
• two successive stages are connected to one another such that they can be charged in parallel and can be discharged in series.
• the surge capacitors are charged by means of a DC charging voltage. Inserted charging resistors not only limit the charging current, but also allow a short-term series connection of the capacitors by means of the spark gaps. The range of the spark gaps are chosen so that they just barely penetrate when reaching the maximum charging voltage. After all the surge capacitors are charged to their quasi-stationary end value of the voltage, the ignition of the lowest spark gap, which then breaks through. At the next spark gap is now the double charge voltage, so that it will certainly ignite. Regardless of the number of stages installed, the discharge process continues due to the addition of the charging voltages of previously fired stages to the last stage.
• impulse voltage pulses of very short duration and simultaneously large amplitude can be generated, which are particularly suitable for testing purposes and experiments in high-voltage technology to verify the insulation resistance and immunity to electromagnetic compatibility.
• the circuit addition also referred to as serial overshoot compensation, thus does not reduce the cause of the overshoot, but compensates for the overshoot in the load capacity, ie in particular on the DUT.
• the overshoot compensation comprises a compensation capacitor and at least one parallelgelope to this discharge resistor or a discharge spark gap, wherein the additional circuit 'sche in serial construction to the test object in the Marx multiplication circuits is grind.
• All of these installed system components of the high-voltage pulse testing system have a considerable spatial extent and must be arranged in a predetermined, dependent on the voltage level minimum distance from each other in the test field.
• defined voltage-dependent minimum distances between voltage-carrying elements and the test field limitation must also be adhered to.
• the space requirement of the entire high-voltage pulse testing system is therefore considerable.
• many transformer manufacturers need to shift the entire high-voltage pulse testing system to change the test object. In this case, the Marx generator and the three other auxiliary components must be individually moved through the test hall and reassembled and set up as a high voltage pulse testing system. This process is time consuming and difficult to handle.
• the object of the present invention is to reduce the voltage-related spatial extent of the auxiliary components, in particular the cut-off spark gap and the overshoot compensation, and thus to reduce the space requirement of the entire high-voltage pulse testing system in order to operate the test hall more efficiently. Furthermore, it is an object of the invention to reduce the capacitive loads of the test circuit as compared to prior art high voltage pulse testing systems.
• the controlled clipping spark gap for this purpose is provided with an additional damping unit consisting of a series-connected damping resistor and a damping inductance and a spark gap connected in parallel thereto.
• the additional damping unit is at least one stage of the cut-off spark gap upstream or downstream of a series circuit, that is electrically connected in series with at least one of the stages of the cut-off spark gap.
• the damping unit absorbs the energy of the oscillation in the maximum voltage of the flash pulse and returns it in the backslash, whereby the effective oscillation is reduced in the maximum voltage of the flash pulse.
• the cut-off spark gap If the cut-off spark gap ignites, it brings the voltage potential along the column to zero. The built-in capacitors of the cut-off spark gap are thus virtually bridged. In addition, the voltage potential that drops across the damping unit must also be brought to zero, which is caused by a short circuit, so an ignition, the parallel to the serial damping resistor and the damping inductance arranged spark gap. Depending on the particular application, the components of the additional damping unit used are interchangeable and thus cover a wide range of parameters of the test standards.
• the additional damping unit is switched on;
• the clipping spark gap according to the invention works like an overshoot compensation.
• the damping unit is bridged and thus ineffective, since due to the short pulse duration no damping by the overshoot compensation is needed.
• the pulse can be cut off after the predetermined period of time with the cut-off spark gap.
• the cut-off spark gap with additional damping unit can be taken out of the test circuit since its functionality is not required for such a test.
• the series circuit of the damping unit consisting of damping resistor and damping inductance, extended by an additional damping capacity, which causes a homogenization of the voltage distribution along the capacitors of the Abschneidefunkenrange.
• another auxiliary component in particular a voltage divider
• Figure 1 shows the circuit diagram of a known from the prior art
• Figure 2 shows the circuit diagram of a damping unit according to the invention
• Figure 3 shows the circuit diagram of a preferred embodiment of an inventive
• Figure 4 shows a preferred embodiment of an inventive
• FIG. 1 shows a circuit diagram of a controlled cut-off spark gap which has become known from DD 143 130. This describes in principle the control of a cut-off spark gap 1 by a capacitive voltage divider 2. The entire arrangement is in the vicinity of a test specimen not shown here in parallel to a high voltage test generator. The test voltage to be cut is divided according to the uniformly selected capacitances uniformly on the capacitors 3 of the voltage divider 2 and thus also on each Einzelfunkenrange 4 of the Abschneidefunkenrange 1 on. The intermediate potentials at the individual capacitor terminals 5 of the capacitive voltage divider 2 are connected to a main electrode 6 of the associated individual spark gap 4 by cross connections 7 for potential control. A second connection to the same single spark gap 4 is made by a cable 8 with an auxiliary electrode 9, which is inserted into said main electrode 6 for triggering the Einzelfunkengroup 4.
• the firing of the cut-off spark gap 1 takes place by externally firing the lowermost individual spark gap 4a with the aid of a trigger pulse applied to the auxiliary electrode 9a, so that the capacitor 3a of this first stage discharges via the single spark gap 6a.
• the discharge current also flows through the transverse connection 7.
• both the cross connection 7, as well as the cable 8 in the condenser 5 have a common connection point, the voltage difference leads to the associated single spark gap 4 between the auxiliary electrode 9 and the main electrode 6 for breakdown and thus triggering this single spark gap 4.
• the continuation of the further stages and thus the entire cut-off spark gap 1 takes place.
• Figure 2 shows the damping unit 20, consisting of a series compensation resistor 21 and a compensation inductor 22 and a parallel connected spark gap 23, which is formed from two opposing calotte 24 and 25.
• the additional damping unit 20 is connected upstream or downstream of at least one stage of the cut-off spark gap 1 to a series circuit, i. electrically connected in series with at least one of the stages of the cut-off spark gap 1.
• the damping unit 20 is arranged at the first stage of the cut-off spark gap 1, the grounding 26 otherwise present there must be routed to the additional damping unit 20.
• the electrical dimensioning of the individual components can be adapted by simple replacement to the external conditions.
• FIG. 4 shows a preferred embodiment of the invention, in which the cut-off spark gap 1 with additional damping unit 20 together with another auxiliary component, namely the voltage divider 32, are arranged on a common base frame 30 with only one head electrode 35 for both auxiliary components.
• the two auxiliary components are shown only schematically in FIG. 4 for reasons of clarity.
• the base frame 30 is thereby formed from, for example, a longitudinally extending, thus linearly constructed and additionally provided laterally mounted arms frame structure. Attached to this base frame 30 and connected to this conductive are the auxiliary components.
• the upper ends of the corresponding auxiliary components are mechanically fixed by means of electrically conductive cross struts 33 and 34. Again with the cross struts 33 and
• the conductive cross struts 33 and 34 thus fulfill both the task of mechanically holding the top electrode 35 and a potential equalization between the auxiliary components and the top electrode
• auxiliary components are electrically connected to one another via a common connection point in the region of the conductive cross struts 33 and 34 and thus have the same voltage level in this area.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Testing Electric Properties And Detecting Electric Faults (AREA)
• Generation Of Surge Voltage And Current (AREA)
• Testing Relating To Insulation (AREA)

Applications Claiming Priority (2)

Publications (1)

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Citations (3)

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• 2009
  • 2009-03-06 DE DE102009012114.5A patent/DE102009012114B4/de active Active
• 2010
  • 2010-01-12 EP EP10700700A patent/EP2404177A1/de not_active Withdrawn
  • 2010-01-12 JP JP2011552333A patent/JP5832303B2/ja active Active
  • 2010-01-12 US US13/254,251 patent/US8344554B2/en active Active
  • 2010-01-12 KR KR1020117023395A patent/KR101646634B1/ko active IP Right Grant
  • 2010-01-12 CN CN201080014839.0A patent/CN102365556B/zh active Active
  • 2010-01-12 RU RU2011140474/28A patent/RU2478215C1/ru active
  • 2010-01-12 WO PCT/EP2010/000096 patent/WO2010099842A1/de active Application Filing
  • 2010-01-12 BR BRPI1012643A patent/BRPI1012643A2/pt not_active Application Discontinuation

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