DE102010017303A1 - Impulse voltage testing system, has high voltage measuring divider installed as intermediate circuit, measurement signal plotting device possessing correction algorithm, and surge voltage generator for producing pulse voltage - Google Patents

Abstract

The system has a high voltage measuring divider (4) installed as an intermediate circuit (7), and a measurement signal plotting device (5) i.e. transient receiver, possessing a correction algorithm. The correction algorithm results from measured electrical parameters of a high voltage connection between the high voltage measuring divider and a high-voltage electrical test object (3) i.e. transformer. A surge voltage generator (1) produces pulse voltage. An optional cutting off-spark gap (2) truncates the voltage during implementation of cut off pulse voltage.

Description

Surge voltage test system with a measuring signal evaluation device with a correction algorithm for voltage tests in the mega-volt range with the aim of reducing the systematic measurement error in quality assurance of insulation in power engineering.

• 1. der Typentest (nach der Entwicklung einer neuen Konstruktion oder Baureihe zum Nachweis der richtigen Auslegung, Dimensionierung und Realisierung) und
• 2. der Routinetest (nach Herstellung eines auszuliefernden Exemplars zum Nachweis der qualitativ richtigen Fertigung). Beide Prüfungen beinhalten die Hochspannungsprüfung. Ein Bestandteil der Hochspannungsprüfung ist die sogenannte Impuls-Spannungsprüfung mittels eines Impuls-Spannungsprüfsystems. Dabei wird das Prüfobjekt mit den im Energieversorgungs- und Übertragungsnetz gleichermaßen auftretenden Belastungen, d. h. mit den Blitzimpuls- und Schaltimpulsspannungen, belastet.

Surge voltage tests are carried out to verify the quality of the high-voltage insulation at high-voltage power engineering equipment. For practical proof, international standards ( IEC 60060-1 . IEC 60060-2 , Transformer test, transformer test) the following test types are defined:

• 1. the type test (after the development of a new design or series to prove the correct design, dimensioning and realization) and
• 2. the routine test (after production of a sample to be delivered to prove the quality production). Both tests include the high voltage test. One component of the high-voltage test is the so-called pulse voltage test by means of a pulse voltage test system. In this case, the test object is loaded with the loads that occur equally in the energy supply and transmission network, ie with the lightning pulse and switching pulse voltages.

The object of the invention is to use an innovative correction algorithm with the aim of reducing the systematic measurement error in quality assurance of the insulation in power engineering with the measurement signal evaluation device of a surge voltage test system.

With the invention, correction functions and relevant differential functions are provided at the measuring-divider output for two different test arrangements, with a secondary circuit or with an intermediate circuit. The correction function u _K (t) is used in the measurement signal evaluation device during the preparation of the measurement signal u _{e, Z} (t), so that the user of the surge voltage test system receives an ideally measured voltage signal u _{e, i} (t).

An advantageous embodiment of the invention is shown in claim 3. Here a transient recorder is used as measuring signal evaluation device. This makes the evaluation via a computer without any problems.

The invention will be explained in more detail with reference to the drawings.

Show it:

1 the definition of parameters of an ideal lightning impulse voltage with the relevant parameters pulse rise time T ₁ and the back half-life T ₂ ,

2 the definition of parameters of an ideal lightning impulse voltage with the relevant parameters pulse rise time T ₁ and the back half-life T ₂ ,

3 the definition of characteristic values of an ideal switching pulse voltage with the relevant parameters pulse rise time T ₁ and back half life T ₂ ,

4 a one-stage equivalent circuit diagram for a surge voltage generator, a cut-off spark gap, a test object, a voltage divider installed as a secondary circuit, and an evaluation unit,

5 an arrangement of a surge test system, consisting of a surge voltage generator, a cut-off spark gap, a test object, a high-voltage measuring device, which is installed as a secondary circuit, and a transient recorder,

6 an arrangement of a surge test system consisting of a surge voltage generator, a cut-off spark gap, a test object, a high-voltage measuring device, which is installed as a DC link, and a transient recorder,

7 a one-stage equivalent circuit diagram for a surge voltage generator, a cut-off spark gap, a test object, a voltage divider that is installed as a DC link and

8th the schematic representation of the application of the correction algorithm u _K (t) in the transient recorder, a voltage signal u _{e, Z} (t), which comes from a arranged as a DC link in the test system high voltage divider and the ideal voltage signal measured u _{e, i} (t ), wherein the ideally measured voltage signal u _{e, i} (t) corresponds to the voltage part signal u _{e, N} (t) installed as a postcircuit.

The ideal pulse voltage u (t) is given by a rising and a falling exponential function with the approximate formula u (t) = u ₀ K (e ^{-t / τ 1 -e -t / τ 1} ) where u _{0 is} the maximum charging voltage of the surge voltage generator 1 . 11 . 21 . 31 , K the utilization factor and τ the two Time constants of the rising or falling exponential term are.

The parameters for the measured pulse rise time T ₁ and for the back half-life T ₂ and their permissible limits are for the flash pulse and the switching pulse in the international standard IEC 60060-1 established. Furthermore, in the IEC 60060-1 set the maximum allowable overshoot of the voltage at the vertex of the function. The 1 and 2 show as an example an ideal pulse voltage. Another applied pulse voltage is the so-called truncated pulse voltage. Depending on the test application, the voltage is reset to 0 by means of a cut-off spark gap (AFC) after the expiry of T _C = 1 μs to 5 μs. 2 . 12 . 22 . 32 reduced. Furthermore, switching pulse voltages are carried out with T ₁ = 250 μs and T ₂ = 2500 μs, see 3 ,

• – dem Stoßspannungsgenerator 1, 11, 21 oder 31 zum Erzeugen der Impulsspannung,
• – der optionalen Abschneide-Funkenstrecke 2, 12, 22 oder 32 zum Abschneiden der Spannung bei der Durchführung einer abgeschnittenen Impulsspannung,
• – dem Prüfobjekt 3, 13, 23 oder 33,
• – dem Hochspannungsmessteiler 4, 14, 24, 34 oder 44, der die gemessene Impulsspannung u_e(t) für die weitere Verarbeitung der Messdaten in eine verwertbare Spannung U < 2000 V umwandelt,
• – dem Messsignalauswertegerät 5, 15, 25, 35 oder 45, vorzugsweise einem Transienten-Rekorder 5, 15, 25, 35 oder 45, der die gemessene Spannung aufzeichnet und
• – optional eine Overshoot-Kompensation, die das Überschwingen der Spannung am Impulsscheitel auf die vorgeschriebenen Werte reduziert. Diese Kompensation ist ein aus einem kapazitiven, ohmschen und induktiven Anteil bestehender Schwingkreis, der als separate Komponente im Prüfsystem integriert, in einer der genannten Prüfsystemkomponenten angeordnet sein kann. Die Stoßkondensatoren C_S des Stoßspannungsgenerators 1, 11, 21 oder 31 werden aufgeladen. Nach dem Zünden der Funkenstrecke SG entlädt sich deren Energie auf das restliche System. Der Dämpfungswiderstand R_D dämpft die Steilheit der ansteigenden exponential Funktion. Der Entlade-Widerstand R_E beeinflusst die abfallende exponential Funktion. Die parasitäre Prüfkreisinduktivität L_P verursacht ein Oszillieren im Scheitel der Impulsfunktion. Die Abschneide-Funkenstrecke 2, 12, 22 oder 32 besteht aus einer Reihenschaltung von Kondensatoren und Widerständen, die ebenfalls induktive Anteile beinhalten können. Der Hochspannungsmessteiler 4, 14, 24, 34 oder 44 kann als kapazitiver, ohmscher oder gemischter Teiler ausgeführt werden. Das Prüfobjekt 3, 13, 23 oder 33 kann durch einen ohmschen, einen kapazitiven und induktiven Anteil dargestellt werden. 4 und 7 zeigen beispielhaft ein Stoßspannungsprüfsystem mit den entsprechenden Komponenten.

The surge voltage system or pulse voltage system consists of the following components:

• - the surge voltage generator 1 . 11 . 21 or 31 for generating the pulse voltage,
• - the optional cut-off spark gap 2 . 12 . 22 or 32 for cutting off the voltage when performing a cut-off pulse voltage,
• - the test object 3 . 13 . 23 or 33 .
• - the high-voltage measuring divider 4 . 14 . 24 . 34 or 44 which converts the measured pulse voltage u _e (t) into a usable voltage U <2000 V for the further processing of the measured data,
• - the measuring signal evaluation device 5 . 15 . 25 . 35 or 45 , preferably a transient recorder 5 . 15 . 25 . 35 or 45 that records the measured voltage and
• - Optionally overshoot compensation, which reduces the overshoot of the voltage at the impulse peak to the prescribed values. This compensation is a resonant circuit consisting of a capacitive, ohmic and inductive component, which can be integrated as a separate component in the test system and can be arranged in one of the test system components mentioned. The surge capacitors C _{S of} the surge voltage generator 1 . 11 . 21 or 31 are charged. After igniting the spark gap SG, their energy is discharged to the rest of the system. The damping resistor R _D attenuates the steepness of the rising exponential function. The discharge resistor R _E influences the falling exponential function. The parasitic Prüfkreisinduktivität L _P causes an oscillation at the apex of the pulse function. The cut-off spark gap 2 . 12 . 22 or 32 consists of a series connection of capacitors and resistors, which may also include inductive components. The high-voltage measuring divider 4 . 14 . 24 . 34 or 44 can be executed as a capacitive, ohmic or mixed divider. The test object 3 . 13 . 23 or 33 can be represented by an ohmic, a capacitive and inductive component. 4 and 7 show an example of a surge test system with the corresponding components.

For the test system writes the IEC 60060-2 , except for the arrangement of the high voltage measuring divider 4 . 14 . 24 . 34 or 44 , no special arrangement before. The high-voltage measuring divider 4 . 14 . 24 . 34 or 44 must be with a separate connection behind the test object 3 . 13 . 23 or 33 , ie as aftertrace 7 or 17 be arranged to reduce the high voltage measurement error. 4 shows the im ICE 60060-2 prescribed test set-up.

Is the high-voltage measuring divider 24 . 34 or 44 as a DC link 28 or 38 a part of the test current flows through it, so that the measured values thus recorded deviate from the ideal state.

In the present invention, the intermediate circuit 28 or 38 clearly defined when the high-voltage measuring divider 24 . 34 or 44 between surge voltage generator 21 or 31 and test object 23 or 33 is arranged, regardless of the arrangement of the remaining test system components. On the other hand, in the present invention, the aftertrace 7 or 17 clearly defined when the high-voltage measuring divider 4 or 14 separately behind the test object 3 or 13 regardless of the arrangement of the remaining test system components, see 4 and 5 ,

For efficient work in the test field, it is clearly advantageous to use the high-voltage measuring divider 24 or 34 as a DC link 28 or 38 to install. As a result, there is only one high-voltage connection between the test system components and the test object 23 or 33 necessary. The present invention is intended to operate the surge voltage test system with a high-voltage measuring device installed as a DC link 24 or 34 which systematically corrects the deviation from the ideal test system design.

The measuring error, caused by the arrangement of the high-voltage measuring divider 24 or 34 as a DC link 28 or 38 , has a systematic character. The correction function u _K (t) results from the difference between the voltage divider u _T (t) and the voltage drop across the test object u _P (t). The correction function results from the electrical parameters of the test system components used. For this purpose, different equations are used, such. For example, u _K (t) = Ldi _P / dt for the two different test arrangements High-voltage measuring divider 4 . 14 as aftertrace 7 . 17 or high-voltage measuring divider 24 . 34 as a DC link 28 . 38 and in deriving the relevant difference function at the measuring divider output. L is the inductance of the high voltage connection between high voltage measuring splitters 4 . 14 . 24 . 34 . 44 and the test object 3 . 13 . 23 . 33 , The test current i _P flows through the mentioned high voltage connection. The ideally measured voltage signal u _{e, i} (t) corresponds to the actual voltage drop u _P (t) across the test object 3 . 13 . 23 . 33 ,

8th shows a test arrangement with a DC link 48 , Here is the correction function u _K (t) in the transient recorder 45 used in the preparation of the measurement signal u _{e, Z} (t), so that the user receives an ideal measured voltage signal u _{e, i} (t), which is evaluated later.

LIST OF REFERENCE NUMBERS

1, 11, 21, 31

Surge voltage generator

2, 12, 22, 32

Cutting spark gap

3, 13, 23, 33

UUT

4, 14, 24, 34, 44

High-voltage measuring divider

5, 15, 25, 35, 45

Messsignalauswertegerät

28, 38, 48

DC

7, 17

Nachkreis

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• IEC 60060-1 [0002]
• IEC 60060-2 [0002]
• IEC 60060-1 [0017]
• IEC 60060-1 [0017]
• IEC 60060-2 [0019]
• ICE 60060-2 [0019]

Claims (4)

Surge voltage test system consisting of a surge voltage generator ( 1 . 11 ), an optional cut-off spark gap ( 2 . 12 ), a test object ( 3 . 13 ), a high-voltage measuring divider ( 4 . 14 ) and a measuring signal evaluation device ( 5 . 15 ), characterized in that the high-voltage measuring divider ( 4 . 14 ) as aftertrace ( 7 . 17 ) and the measuring signal evaluation device ( 5 . 15 ) has a correction algorithm u _K (t) in the form u _K (t) = u _T (t) - u _P (t), which the at the output of the Nachkreis-Hochspannungsmessteilers ( 7 . 17 ) voltage u _{e, N} (t) is corrected into an ideally measured voltage signal u _{e, i} (t), where u _T (t) is the voltage across the voltage divider and μ _P (t) is the voltage across the test object. Surge voltage test system consisting of a surge voltage generator ( 21 . 31 ), an optional cut-off spark gap ( 22 . 32 ), a test object ( 23 . 33 ), a high-voltage measuring divider ( 24 . 34 . 44 ) and a measuring signal evaluation device ( 25 . 35 . 45 ), characterized in that the high-voltage measuring divider ( 24 . 34 . 44 ) as a DC link ( 28 . 38 . 48 ) and the measuring signal evaluation device ( 25 . 35 . 45 ,) has a correction algorithm u _K (t) in the form u _K (t) = u _T (t) - u _P (t), which is the output at the output of the DC link high voltage measuring divider ( 28 . 38 . 48 ) voltage u _{e, N} (t) is corrected into an ideally measured voltage signal u _{e, i} (t), where u _T (t) is the voltage across the voltage divider and μ _P (t) is the voltage across the test object. Surge voltage test system according to Claims 1 and 2, characterized in that the correction algorithm u _K (t) is derived from the estimated electrical parameters of the high-voltage connection between high-voltage measuring splitters ( 4 . 14 . 24 . 34 . 44 ) and the test object ( 3 . 13 . 23 . 33 ) and the current flowing through the high voltage connection. Surge voltage test system according to one of the preceding claims, characterized in that the measuring signal evaluation device ( 5 . 15 . 25 . 35 . 45 ) a transient recorder ( 5 . 15 . 25 . 35 . 45 ). 4th

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