CN101526568A - Grounding test apparatus of reversely connected flow ratio device high voltage bridge based on cable insulation technique - Google Patents

Grounding test apparatus of reversely connected flow ratio device high voltage bridge based on cable insulation technique Download PDF

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Publication number
CN101526568A
CN101526568A CN200910071819A CN200910071819A CN101526568A CN 101526568 A CN101526568 A CN 101526568A CN 200910071819 A CN200910071819 A CN 200910071819A CN 200910071819 A CN200910071819 A CN 200910071819A CN 101526568 A CN101526568 A CN 101526568A
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voltage
former limit
adjustable
test
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CN200910071819A
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CN101526568B (en
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李忠华
郑新龙
郑欢
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哈尔滨理工大学
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Abstract

A grounding test apparatus of reversely connected flow ratio device high voltage bridge based on a cable insulation technique relates to the test apparatus. The invention is proposed to solve the problem that the present flow ratio device capacitance bridge is largely limited in working voltage, difficult in ground insulation and liable to cause electric shock when testing a grounding tested object. Both a passive flow ratio device bridge and an active flow ratio device bridge use a leader cable which is a high-voltage coaxial cable; the high voltage end of the leader cable is connected with a high voltage leading-out wire and the tested object end of the leader cable is connected with the grounding tested object. The high-voltage coaxial cable has excellent insulating property and can isolate the high voltage from a case body and other devices therein, complex ground insulation is unnecessary, and no accident of the electric shock takes place during high voltage test; the terminal of the leader cable employs two terminals including a taped terminal and a cold-shrinkage terminal, thus eliminating the limit of the working voltage, and simultaneously providing a new test apparatus that replaces the traditional reversely connected, diagonally-grounded Schering bridge for the test of the grounding tested object. The invention can be applied to passive and active balanced bridges.

Description

Grounding test apparatus based on the reversely connected flow ratio device high voltage bridge of cable insulation technique

Technical field

The present invention relates to a kind of test unit, be specifically related to a kind of ground connection test product test unit.

Background technology

The method of electric bridge is generally all adopted in the capacitance of insulation of electrical installation and the test of loss factor, and electric bridge commonly used has RC bridge and transformer bridges.For big capacity earth test product such as long cable, power capacitor, the general Schering bridge that has divertor of using is measured.The easiest way is exactly the opposition method that earth terminal is connected in Schering bridge high impedance brachium pontis, and the adjustable brachium pontis of electric bridge just is in high-voltage side like this.In order to guarantee operator's safety, need be contained in electric bridge scalable brachium pontis in the faraday cup, the people is approaching to ensure safety with the current potential of scalable bridge arm in cage.Another kind is the diagonal line connection of Schering bridge, the diagonal line connection causes the testing transformer high-tension coil can not ground connection, high-pressure side has just had equiva lent impedance to be connected to test product to shell and ground, for eliminating consequent error, need on former electric bridge adjustable impedance brachium pontis, provide again and add one group of compensation tunable capacitor, resistance, take the mode of twice balance to be compensated, this makes the running program complexity.Stream is higher than the precision of device capacitance bridge benzathine penicillin G electric bridge, but traditional stream all adopts positive connection at present than device electric bridge, as shown in Figure 1 and Figure 2, though can the testing high voltage test product, but because test product does not have direct ground connection, so can not test the electric capacity of ground connection test product; And that " High-Voltage Technology " that the 2nd phase of nineteen eighty-three publishes introduced is a kind of novel based on the high-tension bridge of stream than device, as shown in Figure 3, solved the problem that adjustment complexity that Schering bridge exists, measured capacitance values can not direct-reading, but during high-potting, box house and high-tension coil and the device voltage that links to each other are very high, be very easy to electric shock accidents take place and be difficult to accomplish good insulation over the ground, and its operating voltage only is confined to 3~10 kilovolts, the very difficult satisfied more demand of high-voltage test.

Summary of the invention

Existing stream is bigger than the operating voltage limitation that device capacitance bridge exists when the high-potting test ground connection test product in order to solve in the present invention, high-tension coil and the device that links to each other (casing) insulation difficulty, the problem of easily getting an electric shock over the ground, and the grounding test apparatus based on the reversely connected flow ratio device high voltage bridge of cable insulation technique that proposes.

Grounding test apparatus based on the reversely connected flow ratio device high voltage bridge of cable insulation technique, it comprises passive flow ratio device electric bridge and lead cable, and passive flow ratio device electric bridge is made up of power transformer, first standard capacitor, first resistance, second adjustable condenser, detection transformer and balance indicator with former limit of the adjustable number of turn; The former limit of power transformer links to each other with working power, and the two ends of the secondary of power transformer link to each other with ground wire with an end of first standard capacitor respectively; The other end of first standard capacitor links to each other with an end of first resistance and an end of second adjustable condenser respectively; The other end of second adjustable condenser links to each other with ground wire; The other end of first resistance links to each other with an end on the former limit of the detection transformer on the former limit with adjustable number of turn, has the other end ground connection on former limit of detection transformer on the former limit of the adjustable number of turn; The two ends of secondary of detection transformer with former limit of the adjustable number of turn link to each other with two terminals of balance indicator respectively; Lead cable is a high-pressure coaxial cable; The high-pressure side of lead cable links to each other with the non-earth terminal of the secondary of power transformer, and the test product end of lead cable links to each other with the test end of ground connection test product.

Grounding test apparatus based on the reversely connected flow ratio device high voltage bridge of cable insulation technique, it includes source and course than device electric bridge and lead cable, and active power flow is made up of power transformer, first standard capacitor, second resistance, voltage changer, detection transformer and balance indicator with former limit of two adjustable numbers of turn than device electric bridge; Voltage changer is made up of tertiary voltage conversion capacitor, amplifier and voltage transformation transformer; The two ends on the former limit of voltage transformation transformer link to each other with two input ends of amplifier respectively, the secondary mid point of voltage transformation transformer links to each other with ground wire, positive voltage terminal+the E of the secondary of voltage transformation transformer links to each other with an end of second resistance, the other end of second resistance links to each other with an end on the former limit of the first adjustable number of turn of the detection transformer on the former limit with two adjustable numbers of turn, and the other end on former limit of the first adjustable number of turn of detection transformer with former limit of two adjustable numbers of turn links to each other with ground wire with first output terminal of amplifier respectively; Negative voltage side-the E of the secondary of voltage transformation transformer links to each other with an end of tertiary voltage conversion capacitor, and the other end of tertiary voltage conversion capacitor links to each other with an end on the former limit of the second adjustable number of turn of the detection transformer on second output terminal of amplifier A and the former limit with two adjustable numbers of turn respectively; The former limit of power transformer links to each other with working power, and the secondary of power transformer links to each other with ground wire with an end of first standard capacitor respectively; The other end of first standard capacitor links to each other with the other end on the former limit of the second adjustable number of turn of the detection transformer on the former limit with two adjustable numbers of turn; The secondary two ends of detection transformer with former limit of two adjustable numbers of turn link to each other with the two ends of balance indicator respectively; Lead cable is a high-pressure coaxial cable; The high-pressure side of lead cable links to each other with non-ground connection one end of the secondary of power transformer, and the test product end of lead cable links to each other with the test end of ground connection test product.

Lead cable 1 of the present invention adopts high-pressure coaxial cable as flowing than the ratio coil that is connected with product to be tested in the device, the on high-tension side electric current of ground connection test product is drawn the inflow ratio device, be grounded the comparison of test product electric current and standard capacitor electric current, reach the purpose of test.High-pressure coaxial cable has the good insulation characteristic, high voltage and casing and inner other device isolation thereof can be need not to do the intricately insulation against ground, electric shock accidents can not take place during high-potting; The terminal of lead cable 1 adopts wrapped terminal or two kinds of terminals of shrinkage terminal, has eliminated the limitation of operating voltage, and wrapped terminal is mainly used in the following electric pressure of 10kV, and the shrinkage terminal is mainly used in the above electric pressure of 10kV; Reversal connection, diagonal line ground connection Schering bridge and the stream that provides a kind of alternative tradition to be used for the ground connection test product to measure is than the new proving installation of device electric bridge.The present invention can be widely used in passive balanced bridge and active balancing electric bridge.

Description of drawings

Fig. 1 is the structural representation of traditional passive flow ratio device electric bridge; Fig. 2 is the traditional active power flow structural representation than device electric bridge; Fig. 3 is the structural representation after traditional stream replaces than device electric bridge; Fig. 4 is the structural representation on the present invention the is applied in passive balanced bridge; Fig. 5 is applied in structural representation on the active balancing electric bridge for the present invention; Fig. 6 is the current compensation principle schematic of lead cable 1 of the present invention; Fig. 7 is applied in the wrapped terminal structure synoptic diagram of the following electric pressure of 10kV for lead cable 1; Fig. 8 is applied in the shrinkage terminal structure synoptic diagram of the above electric pressure of 10kV for lead cable 1.

Embodiment

Embodiment one: present embodiment is described in conjunction with Fig. 1, present embodiment comprises passive flow ratio device electric bridge and lead cable 1, and passive flow ratio device electric bridge is made up of power transformer 1-3, the first standard capacitor C1, first resistance R 1, the second adjustable condenser C2, detection transformer 1-4 and balance indicator D with former limit of the adjustable number of turn; The former limit of power transformer 1-3 links to each other with working power, and the two ends of the secondary of power transformer 1-3 link to each other with ground wire with the end of the first standard capacitor C1 respectively; The other end of the first standard capacitor C1 links to each other with an end of first resistance R 1 and the end of the second adjustable condenser C2 respectively; The other end of the second adjustable condenser C2 links to each other with ground wire; The other end of first resistance R 1 links to each other with an end on the former limit of the detection transformer 1-4 on the former limit with adjustable number of turn, has the other end ground connection on former limit of detection transformer 1-4 on the former limit of the adjustable number of turn; The two ends of secondary of detection transformer 1-4 with former limit of the adjustable number of turn link to each other with two terminals of balance indicator D respectively; Lead cable 1 is a high-pressure coaxial cable; The high-pressure side of lead cable 1 links to each other with the non-earth terminal of the secondary of power transformer 1-3, and the test product end of lead cable 1 links to each other with the test end of ground connection test product 2.

Embodiment two: in conjunction with Fig. 1, Fig. 3 present embodiment is described, present embodiment is that with embodiment one difference the external shielding layer 1-1 of lead cable 1 links to each other with ground wire at high-pressure side one end of lead cable 1.Other composition is identical with embodiment one with connected mode.External shielding layer 1-1 is in order to eliminate the influence that lead cable 1 ground capacitance and leakage conductance are measured test product in the purpose of the high-pressure side one end ground connection of lead cable 1.The electric current of the ground capacitance of lead cable 1 and the leakage conductance of flowing through is flowed into by its core, is returned by its external shielding layer 1-1 again, does not therefore produce magnetic flux at stream than the inside unshakable in one's determination of device, only passes test product electric current unshakable in one's determination and produces magnetic flux and participate in bridge balance.

Embodiment three: in conjunction with Fig. 4, Fig. 5 present embodiment is described, present embodiment and embodiment one or two differences are that the terminal of lead cable 1 adopts wrapped terminal or shrinkage terminal.Other composition is identical with embodiment one or two with connected mode.Wrapped terminal is mainly used in the test product test of the following electric pressure of 10kV; The shrinkage terminal is mainly used in the test product test of the above electric pressure of 10kV.

Embodiment four: present embodiment is described in conjunction with Fig. 2, present embodiment includes source and course than device electric bridge and lead cable 1, and active power flow is made up of power transformer 1-3, the first standard capacitor C1, second resistance R 2, voltage changer, detection transformer 1-6 and balance indicator D with former limit of two adjustable numbers of turn than device electric bridge; Voltage changer is made up of tertiary voltage conversion capacitor C3, amplifier A and voltage transformation transformer 1-5; The two ends on the former limit of voltage transformation transformer 1-5 link to each other with two input ends of amplifier A respectively, the secondary mid point of voltage transformation transformer 1-5 links to each other with ground wire, positive voltage terminal+the E of the secondary of voltage transformation transformer 1-5 links to each other with an end of second resistance R 2, the other end of second resistance R 2 links to each other with the end of the former limit 1-6-1 of the first adjustable number of turn of the detection transformer 1-6 on the former limit with two adjustable numbers of turn, and the other end of former limit 1-6-1 of the first adjustable number of turn of detection transformer 1-6 with former limit of two adjustable numbers of turn links to each other with ground wire with first output terminal of amplifier A respectively; Negative voltage side-the E of the secondary of voltage transformation transformer 1-5 links to each other with the end of tertiary voltage conversion capacitor C3, and the other end of tertiary voltage conversion capacitor C3 links to each other with the end of the former limit 1-6-2 of the second adjustable number of turn of the detection transformer 1-6 on second output terminal of amplifier A and the former limit with two adjustable numbers of turn respectively; The former limit of power transformer 1-3 links to each other with working power, and the secondary of power transformer 1-3 links to each other with ground wire with the end of the first standard capacitor C1 respectively; The other end of the first standard capacitor C1 links to each other with the other end of the former limit 1-6-2 of the second adjustable number of turn of the detection transformer 1-6 on the former limit with two adjustable numbers of turn; The two ends of secondary of detection transformer 1-6 with former limit of two adjustable numbers of turn link to each other with two terminals of balance indicator D respectively; Lead cable 1 is a high-pressure coaxial cable; The high-pressure side of lead cable 1 links to each other with non-ground connection one end of the secondary of power transformer 1-3, and the test product end of lead cable 1 links to each other with the test end of ground connection test product 2.

Embodiment five: in conjunction with Fig. 2, Fig. 3 present embodiment is described, present embodiment is that with embodiment four differences the external shielding layer 1-1 of lead cable 1 links to each other with ground wire at high-pressure side one end of lead cable 1.Other composition is identical with embodiment four with connected mode.

Embodiment six: in conjunction with Fig. 4, Fig. 5 present embodiment is described, present embodiment and embodiment four or five differences are that the terminal of lead cable 1 adopts wrapped terminal or shrinkage terminal.Other composition is identical with embodiment four or five with connected mode.

The principle of work of the present invention and the course of work: the present invention can test dielectric strength and be lower than minimum limit value in lead cable 1, the first standard capacitor C1, the ground connection test product 2 three's dielectric strengths and capacitance less than the M first standard capacitor C1 capacity doubly, the value of M is that the detection transformer 1-4 with former limit of the adjustable number of turn is indicated to the adjustable former limit number of turn hour, passive flow ratio device electric bridge application of formula tan δ=ω R at balance indicator D 1C 2With C X = M · C 1 1 + tan 2 δ , Active power flow is than device electric bridge application of formula tan δ = N a ω C 3 N o R 2 And C X=C 1N o, can try to achieve the loss tangent and the capacitance of ground connection test product.Wherein in two formula, parameters C XCapacitance for ground connection test product 2.

Illustrate that in conjunction with Fig. 1 the present invention is applied in the principle of work and the course of work on the passive balanced bridge, at first, introduce the high-pressure side and the first standard capacitor C1 that high voltage is connected respectively to lead cable 1 from power transformer 1-3, the test product end of lead cable 1 links to each other with the ground connection test product and constitutes the loop, and the external shielding layer 1-1 of lead cable 1 links to each other with ground wire at high-pressure side one end of lead cable 1.The other end of the first standard capacitor C1 is connected with first resistance R 1, serial connection has ground connection behind the former limit of detection transformer 1-4 on former limit of the adjustable number of turn again, the second adjustable condenser C2, the one end other end ground connection that links to each other with the node of the first standard capacitor C1 and first resistance R 1.By regulating the former limit of the second adjustable condenser C2 and the detection transformer 1-4 on former limit with adjustable number of turn, make balance indicator D be indicated to adjustable minimum, promptly be considered as bridge balance, utilize ampere-turn equilibrium condition and geometric knowledge can extrapolate loss tangent to be this moment:

tanδ=ω·R 1·C 2

The capacitance of tested sample is:

C x = M · C 1 1 + tan 2 δ

Illustrate that in conjunction with Fig. 2 the present invention is applied in the principle of work and the course of work on the active balancing electric bridge, at first, introduce the high-pressure side and the first standard capacitor C1 that high voltage is connected respectively to lead cable 1 from power transformer 1-3, the test product end of lead cable 1 links to each other with the ground connection test product and constitutes the loop, and the external shielding layer 1-1 of lead cable 1 links to each other with ground wire at high-pressure side one end of lead cable 1.Another termination of the first standard capacitor C1 has the negative voltage side-E that enters the secondary of voltage transformation transformer 1-5 behind the former limit 1-6-2 of the second adjustable number of turn of detection transformer 1-6 on former limit of two adjustable numbers of turn, ground connection after the positive voltage terminal+E of the secondary of voltage transformation transformer 1-5 is connected in series second resistance R 2 and has the former limit 1-6-1 of the first adjustable number of turn of detection transformer 1-6 on former limit of two adjustable numbers of turn.Have the former limit of first and second adjustable number of turn of detection transformer 1-6 on the former limit of two adjustable numbers of turn by adjusting, make balance indicator D be indicated to adjustable minimum, promptly be considered as bridge balance, obtain the number of turn N on the former limit of the first adjustable number of turn 0Number of turn N with the former limit of the second adjustable number of turn aAt this moment, utilize the ampere-turn equilibrium condition can release capacitance to be:

C x=C 1·C o

The loss tangent of tested sample is:

tan δ = N a ω C 3 N o R 2

Parameter ω is the voltage angle frequency in the formula.

Claims (6)

1, based on the grounding test apparatus of the reversely connected flow ratio device high voltage bridge of cable insulation technique, it comprises passive flow ratio device electric bridge and lead cable (1), and passive flow ratio device electric bridge is made up of power transformer (1-3), first standard capacitor (C1), first resistance (R1), second adjustable condenser (C2), detection transformer (1-4) and balance indicator (D) with former limit of the adjustable number of turn; The former limit of power transformer (1-3) links to each other with working power, and the two ends of the secondary of power transformer (1-3) link to each other with ground wire with an end of first standard capacitor (C1) respectively; The other end of first standard capacitor (C1) links to each other with an end of first resistance (R1) and an end of second adjustable condenser (C2) respectively; The other end of second adjustable condenser (C2) links to each other with ground wire; The other end of first resistance (R1) links to each other with an end on the former limit of the detection transformer (1-4) on the former limit with adjustable number of turn, has the other end ground connection on former limit of detection transformer (1-4) on the former limit of the adjustable number of turn; The two ends of secondary of detection transformer (1-4) with former limit of the adjustable number of turn link to each other with two terminals of balance indicator (D) respectively; Lead cable (1) is a high-pressure coaxial cable; The high-pressure side of lead cable (1) links to each other with the non-earth terminal of the secondary of power transformer (1-3), and the test product end of lead cable (1) links to each other with the test end of ground connection test product (2).
2, the grounding test apparatus of the reversely connected flow ratio device high voltage bridge based on cable insulation technique according to claim 1 is characterized in that the external shielding layer (1-1) of lead cable (1) links to each other with ground wire at high-pressure side one end of lead cable (1).
3, the grounding test apparatus of the reversely connected flow ratio device high voltage bridge based on cable insulation technique according to claim 1 and 2 is characterized in that the terminal of lead cable (1) adopts wrapped terminal or shrinkage terminal.
4, based on the grounding test apparatus of the reversely connected flow ratio device high voltage bridge of cable insulation technique, it includes source and course than device electric bridge and lead cable (1), and active power flow is made up of power transformer (1-3), first standard capacitor (C1), second resistance (R2), voltage changer, detection transformer (1-6) and balance indicator (D) with former limit of two adjustable numbers of turn than device electric bridge; Voltage changer is made up of tertiary voltage conversion capacitor (C3), amplifier (A) and voltage transformation transformer (1-5); The two ends on the former limit of voltage transformation transformer (1-5) link to each other with two input ends of amplifier (A) respectively, the secondary mid point of voltage transformation transformer (1-5) links to each other with ground wire, the positive voltage terminal of the secondary of voltage transformation transformer (1-5) (+E) end with second resistance (R2) links to each other, the other end of second resistance (R2) links to each other with an end on the former limit (1-6-1) of the first adjustable number of turn of the detection transformer (1-6) on the former limit with two adjustable numbers of turn, and the other end on former limit (1-6-1) of the first adjustable number of turn of detection transformer (1-6) with former limit of two adjustable numbers of turn links to each other with ground wire with first output terminal of amplifier (A) respectively; (E) end with tertiary voltage conversion capacitor (C3) links to each other the negative voltage side of the secondary of voltage transformation transformer (1-5), and the other end of tertiary voltage conversion capacitor (C3) links to each other with an end on the former limit (1-6-2) of the second adjustable number of turn of the detection transformer (1-6) on second output terminal of amplifier (A) and the former limit with two adjustable numbers of turn respectively; The former limit of power transformer (1-3) links to each other with working power, and the secondary of power transformer (1-3) links to each other with ground wire with an end of first standard capacitor (C1) respectively; The other end of first standard capacitor (C1) links to each other with the other end on the former limit (1-6-2) of the second adjustable number of turn of the detection transformer (1-6) on the former limit with two adjustable numbers of turn; The two ends of secondary of detection transformer (1-6) with former limit of two adjustable numbers of turn link to each other with two terminals of balance indicator (D) respectively; Lead cable (1) is a high-pressure coaxial cable; The high-pressure side of lead cable (1) links to each other with non-ground connection one end of the secondary of power transformer (1-3), and the test product end of lead cable (1) links to each other with the test end of ground connection test product (2).
5, the grounding test apparatus of the reversely connected flow ratio device high voltage bridge based on cable insulation technique according to claim 4 is characterized in that the external shielding layer (1-1) of lead cable (1) links to each other with ground wire at high-pressure side one end of lead cable (1).
6, according to the grounding test apparatus of claim 4 or 5 described reversely connected flow ratio device high voltage bridges based on cable insulation technique, it is characterized in that the terminal of lead cable (1) adopts wrapped terminal or shrinkage terminal.
CN2009100718196A 2009-04-17 2009-04-17 Grounding test apparatus of reversely connected flow ratio device high voltage bridge based on cable insulation technique CN101526568B (en)

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CN2009100718196A CN101526568B (en) 2009-04-17 2009-04-17 Grounding test apparatus of reversely connected flow ratio device high voltage bridge based on cable insulation technique

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CN2009100718196A CN101526568B (en) 2009-04-17 2009-04-17 Grounding test apparatus of reversely connected flow ratio device high voltage bridge based on cable insulation technique

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102096023A (en) * 2010-12-17 2011-06-15 西安四方机电有限责任公司 Device and method for testing power cable fault

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102096023A (en) * 2010-12-17 2011-06-15 西安四方机电有限责任公司 Device and method for testing power cable fault
CN102096023B (en) * 2010-12-17 2012-09-26 西安四方机电有限责任公司 Device and method for testing power cable fault

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