CN108535587B - Transformer wiring fault testing device - Google Patents
Transformer wiring fault testing device Download PDFInfo
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- CN108535587B CN108535587B CN201810355724.6A CN201810355724A CN108535587B CN 108535587 B CN108535587 B CN 108535587B CN 201810355724 A CN201810355724 A CN 201810355724A CN 108535587 B CN108535587 B CN 108535587B
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- 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
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/62—Testing of transformers
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- 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
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/66—Testing of connections, e.g. of plugs or non-disconnectable joints
- G01R31/67—Testing the correctness of wire connections in electric apparatus or circuits
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- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
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- Testing Relating To Insulation (AREA)
Abstract
The invention provides a transformer wiring fault testing device which comprises a three-phase variable frequency test power supply, a three-phase collector, a low-voltage side wiring load combination switch, a simulation load resistance box, a control device and testing and control software. The invention adopts low-voltage test, thus remarkably improving the test safety. Particularly, the test cable insulation sheath device is arranged, so that the interference of site crosstalk voltage on the test can be eliminated, the damage of the crosstalk high voltage on a test system is avoided, and the personal safety of site operators is guaranteed.
Description
Technical Field
The invention relates to the field of power equipment, in particular to a transformer wiring fault testing device.
Background
When debugging and running of the power transformer are carried out, an essential step is wiring inspection. The wiring check generally refers to checking for a fault condition caused by a faulty connection of the phase or amplitude of the signal at the low voltage output of the transformer due to a human wiring error. The wiring inspection is generally performed in field test by raising current to the transformer, and then observing signal waveform or phase at the low-voltage end through a voltage transformer and a current transformer connected with the transformer. When the wiring of the terminal of the transformer is wrong, even if the wiring of the voltage transformer and the current transformer is not wrong, the protection device still acts to cause the chain power failure reaction. Therefore, in the prior art, there is a safety risk in the method of directly boosting the voltage and current of the transformer according to the rated working condition.
During conventional testing, the load box and the load combination switch are generally considered to belong to absolute low-voltage safety equipment, and parameters are conveniently adjusted in the testing process and are relatively close to testers. In fact, because the output terminal on the low-voltage side of the field transformer substation is several meters high, in order to guarantee national economic operation and reduce economic loss during testing, other adjacent lines cannot be powered off, and therefore high voltage can be induced near the low-voltage side of the transformer, on one hand, field interference is caused, on the other hand, the crosstalk voltage is output to a load box body, and personal safety hazards are brought to operators.
There are several cases that lead to line voltage crosstalk into the test low side loop:
1) an equivalent capacitor is formed between the signal wiring and the ground during testing, and the equivalent capacitor between the test wires is increased along with the increase of the length of the test wires due to the fact that the number of the test wires of the transformer is large and a parallel multi-strand structure exists. Therefore, in an environment where the test cable has a length of more than ten meters, the test line and a nearby high-voltage line are likely to form a capacitive coupling relationship, and an ac high voltage is coupled to the test wire by an equivalent capacitive effect.
2) The phenomenon of corona discharge or other fault type discharge exists in nearby circuits, the discharge voltage can reach thousands of volts to tens of kilovolts, and the resonance phenomenon can occur due to the insulation distribution parameters of the circuits during discharge, so that the discharge signal frequency can have power frequency, intermediate frequency and high frequency signals. The high-frequency signal has a longer transmission and coupling distance, and under the condition, a new energy release channel is possibly established between a transformer test line and a nearby discharge point and has stronger conductivity than a power frequency signal.
3) The crosstalk high voltage signal is transmitted from the high voltage side via the transformer step-down to the low voltage side, which voltage value is still much higher than the voltage in the low voltage test mode.
4) The crosstalk high voltage signal is released directly through the low side cable and is thus introduced more directly onto the load box.
In summary, it can be known from the analysis that, for the transformer test scheme in the low-voltage test mode, although the signal is reduced and the anti-interference capability is obtained after frequency conversion, the crosstalk voltage in the field is difficult to eliminate, and the voltage strength of the crosstalk may be much higher than the insulation strength and the safety level of the operation of the test system itself. Therefore, innovations in the above schemes are needed to solve the safety problem.
It is of course necessary to supplement that when the field test is completely performed with the high voltage rating test, although the crosstalk voltage is also present, the insulation rating of the whole test system is in accordance with the condition equal to or higher than the rated voltage of the transformer, and there is a corresponding requirement for the safety distance of the tester, so that the problem of crosstalk of the adjacent live lines mainly occurs in the low voltage test solution.
Disclosure of Invention
In order to solve the problems, the invention provides a transformer wiring fault testing device, a tested transformer is connected with a three-phase variable frequency test power supply, a low-voltage side wiring load combination switch and a simulation load, and the voltage and the current of the high-voltage side, the low-voltage side or the load side of the tested transformer are collected through a three-phase collector, so that the safety risk caused by the fact that the transformer is directly boosted and upflowed according to rated working conditions when the debugging and the operation of a power transformer are carried out in the prior art is overcome.
In particular to a transformer wiring fault testing device which is characterized by comprising a three-phase variable frequency test power supply, a test cable, a three-phase collector, a low-voltage side wiring load combination switch, a simulated load resistance box, a control device and test and control software, the output end of the three-phase variable frequency test power supply is connected with the high-voltage side of the tested transformer through the test cable, the low-voltage side of the tested transformer is connected with the analog load resistance box through the test cable and the low-voltage side wired load combination switch, the high-voltage side of the tested transformer is connected with the three-phase collector after being subjected to voltage reduction coupling through the test cable, the three-phase collector is also connected with the low-voltage side of the tested transformer or the simulation load resistance box through the test cable, and the control equipment is respectively connected with the three-phase collector and the three-phase variable frequency test power supply;
the three-phase variable frequency test power supply is controlled by the control equipment to realize the adjustment of output frequency and output voltage;
the low-voltage side wiring load combination switch is used for realizing wiring switching between the low-voltage side three-phase output circuit of the test transformer and the simulation load resistance box;
the simulation load resistance box comprises at least three groups of resistors and is used for realizing three-phase star load connection or three-phase triangular load connection;
the three-phase collector is used for collecting three-phase current and voltage of the high-voltage side and the low-voltage side or the load side of the tested transformer;
the control equipment is an industrial personal computer or a single chip microcomputer, the test and control software is deployed on the industrial personal computer or an upper computer in communication connection with the control equipment, and the test and control software is used for setting the output frequency of the three-phase variable frequency test power supply and the sampling rate of the three-phase collector, controlling the information interaction of the control equipment and the three-phase collector, and processing and displaying the collected three-phase voltage and current.
As an improvement, the transformer wiring fault testing device further comprises a test cable insulating sheath device, the test cable insulating sheath device is sleeved outside a test cable connected with the high-voltage side and the low-voltage side of the tested transformer, the test cable insulating sheath device is of a three-layer structure, the outer layer is an insulating layer, the middle layer is a copper mesh, the inner layer is an insulating layer, the copper mesh is provided with conductor output ends at two edges of the cable insulating sheath, and the conductor output ends are directly grounded or grounded through a ground discharge loop.
Preferably, the test cable insulating sheath device is a hollow round structure, a hollow square structure or other hole-shaped structures.
Preferably, the test cable insulating sheath device is a half-open or telescopic fixed structure.
Preferably, the ground discharge circuit is a short circuit switch, a grounded copper wire, a resistor with ground, a resistor box with ground or a vacuum discharge gap module with ground.
Preferably, the adjustable range of the output frequency of the three-phase variable frequency test power supply is 10Hz to 5kHz, and the adjustable range of the output voltage is 10V to 600V.
Preferably, the resistance values of the resistors in the analog load resistance box can be independently adjusted, and the adjustable range of the resistance values of the resistors is 0-500 ohms.
Preferably, the resistor in the analog load resistor box is a pure resistor, a capacitor resistor or an inductor composite impedance unit, the adjustable range of the capacitor is 0-10uF, and the adjustable range of the inductor is 0-100 mH.
Preferably, the low-voltage side wired load combination switch realizes the wiring switching through a knob manual mode or a numerical control mode.
The invention has the beneficial effects that:
(1) the invention provides a transformer wiring fault testing device, which adopts low-voltage testing and overcomes the safety risk brought by the prior art that the transformer is directly boosted and upflowed according to rated working conditions when debugging and running of a power transformer are carried out.
(2) The invention can simulate the fault of terminal wiring, can repeatedly demonstrate, improves the efficiency of field debugging, realizes field detection of wiring errors, and can carry out technical training and communication of wiring detection on the field.
(3) The invention is provided with the test cable insulation sheath device, can eliminate the interference of site crosstalk voltage on the test, avoids the damage of the crosstalk high voltage on the test system, and ensures the personal safety of site operators.
Drawings
Fig. 1 is a structural diagram of an embodiment of a transformer wiring fault testing apparatus provided in the present invention.
Fig. 2 is a second structural diagram of an embodiment of a transformer wiring fault testing device provided by the invention.
Fig. 3 is an axial cross-sectional view of a test cable insulation sheath arrangement.
Fig. 4 is a radial cross-sectional view of the test cable insulation sheath arrangement.
Detailed Description
In order to more clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described with reference to the accompanying drawings.
Fig. 1 shows an embodiment of a transformer wiring fault testing apparatus according to the present invention. A transformer wiring fault testing device comprises a three-phase variable frequency test power supply, a test cable, a three-phase collector, a low-voltage side wiring load combination switch, a simulated load resistance box, a control device and test and control software, wherein the output end of the three-phase variable frequency test power supply is connected with the high-voltage side of a tested transformer through the test cable; the three-phase variable frequency test power supply is controlled by the control equipment to realize the regulation of output frequency and output voltage; the low-voltage side wiring load combination switch is used for realizing wiring switching between a low-voltage side three-phase output circuit of the test transformer and the simulation load resistance box, so that the phase sequence of an output end is changed, and wiring fault simulation is realized; the simulation load resistance box comprises at least three groups of resistors and is used for realizing three-phase star load connection or three-phase triangular load connection; the three-phase collector is used for collecting three-phase current and voltage at the high-voltage side and the low-voltage side or the load side of the tested transformer; the control device is an industrial personal computer or a single chip microcomputer, the testing and control software is deployed on the industrial personal computer or an upper computer in communication connection with the control device, the testing and control software is used for setting the output frequency of the three-phase variable frequency test power supply and the sampling rate of the three-phase collector, controlling the information interaction of the control device and the three-phase collector, and processing and displaying the collected three-phase voltage and current.
The three-phase collector synchronously collects the current and the voltage of the high-voltage side of the three-phase transformer and the current and the voltage of the low-voltage side or the load side, and the collection channels of the three-phase collector can be at least 12 channels, wherein the three-phase voltage and the current of the high-voltage side are 6 channels, and the three-phase voltage and the current of the low-voltage side or the load side are 6 channels.
As a preferred embodiment, the adjustable range of the output frequency of the three-phase variable frequency test power supply is 10Hz to 5kHz, and the adjustable range of the output voltage is 10V to 600V.
The method for improving and changing the test frequency can effectively resist field interference and change the excitation working point of the transformer, thereby effectively reducing the test voltage. According to the experimental data of the inventor, the invention provides the frequency range of the related frequency conversion test. Moreover, the variable frequency test power supply can be used for testing a plurality of frequency points, and finally, data of different frequency points are gathered for further analysis, so that the variable frequency test power supply has better prospect.
As a preferred embodiment, the resistance values of the resistors in the analog load resistor box can be independently adjusted, and the test of the three-phase unbalanced load can be realized. The adjustable range of the resistance value of the resistor is 0-500 ohms.
As a preferred embodiment, the resistor in the analog load resistor box is a pure resistor, a capacitor resistor or an inductor composite impedance unit, the adjustable range of the capacitor is 0-10uF, and the adjustable range of the inductor is 0-100 mH.
In a preferred embodiment, the low-voltage side wiring load combination switch realizes wiring switching in a manual or numerical control mode through a knob.
In performing field testing, one example is: and setting a low-voltage side wiring load combination switch, exchanging the phase A and the phase B, keeping the phase C unchanged, adjusting the three-phase load resistance value of the analog load resistance box to be zero, namely in a short-circuit state, setting the transformation ratio of the three-phase transformer to be 500:1, setting the controlled frequency of the three-phase variable frequency test power supply to be 300Hz and the voltage to be 500V, and outputting the three-phase voltage to the tested three-phase transformer, wherein the voltage of the low-voltage side is 1V. Since the three-phase load box is in a short-circuit state, the load at the low-voltage-side output end of the transformer under test is only the resistance value of the output connection, and the low-voltage-side current value is 1V/0.5=2 amperes when the resistance value is very small and is set to 0.5 ohm. When all the test sites are powered off and high-voltage crosstalk coupling does not exist, the scheme can meet the requirements of site test.
However, in the actual development process, the inventor finds that in the field low-voltage test, although the advantage is obvious, the situation that adjacent high voltage is coupled exists, the high voltage damages equipment and endangers personal safety, and therefore safety issues must be considered under the condition of considering the method of the low-voltage test.
To solve the above problems, a second embodiment of the transformer wiring fault testing apparatus according to the present invention is shown in fig. 2. On the basis of the embodiment, the transformer wiring fault testing device further comprises a test cable insulating sheath device, the test cable insulating sheath device is sleeved outside a test cable connected with the high-voltage side and the low-voltage side of the tested transformer, the test cable insulating sheath device is of a three-layer structure, the outer layer is an insulating layer, the middle layer is a copper mesh, the inner layer is an insulating layer, the copper mesh is provided with conductor output ends at two edges of the cable insulating sheath, and the conductor output ends are directly grounded or grounded through a ground discharge loop.
The test cable insulation jacket arrangement functions to shield the cable, especially from voltage crosstalk in the parallel multi-strand region. In the arrangement of the three-layer structure: the outer layer is made of insulating rubber materials, and can resist insulating voltage of more than 100 kV; the middle layer adopts a shielding layer with a flexible copper mesh structure; the inner layer is poured and isolated by adopting insulating rubber or flexible insulating materials.
The whole test cable insulation sheath device is of a hollow structure, and a test lead passes through the hollow position of the test cable insulation sheath device before testing, so that the test cable insulation sheath device can be used as a main body insulation carrier for bearing external coupling voltage. Under the condition, the copper mesh in the insulating sheath device of the test cable is still a conductor structure and is still possibly subjected to high-voltage coupling with an adjacent high-voltage live line, so that when the coupling voltage is too high and the isolation layer is subjected to insulation breakdown, the high voltage of the isolation layer can not be introduced into a test lead, and the energy is released by grounding the copper mesh in the insulating sheath device of the test cable or discharging through the copper mesh and gaps. At the moment, the external potential of the multi-strand test line sleeved in the test cable insulating sheath device is zero, so that the test line is protected from being influenced by coupling voltage, and the equipment safety and the personal safety are protected.
As a preferred embodiment, the test cable insulating sheath device is a hollow round, hollow square or other hole-like structure.
As a preferred embodiment, the test cable insulating sheath device is of a semi-open or telescopically fixed structure.
As a preferred embodiment, the ground discharge circuit is a short circuit switch, a grounding copper wire, a resistor with grounding, a resistor box with grounding or a vacuum discharge gap module with grounding.
The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention, and it is therefore to be understood that the invention is not limited by the scope of the appended claims.
Claims (6)
1. A transformer wiring fault testing device is characterized by comprising a three-phase variable frequency test power supply, a test cable, a three-phase collector, a low-voltage side wiring load combination switch, a simulated load resistance box, control equipment, test and control software and a test cable insulating sheath device, the output end of the three-phase variable frequency test power supply is connected with the high-voltage side of the tested transformer through the test cable, the low-voltage side of the tested transformer is connected with the analog load resistance box through the test cable and the low-voltage side wired load combination switch, the high-voltage side of the tested transformer is connected with the three-phase collector after being subjected to voltage reduction coupling through the test cable, the three-phase collector is also connected with the low-voltage side of the tested transformer or the simulation load resistance box through the test cable, and the control equipment is respectively connected with the three-phase collector and the three-phase variable frequency test power supply;
the three-phase variable frequency test power supply is controlled by the control equipment to realize the adjustment of output frequency and output voltage;
the low-voltage side wiring load combination switch is used for realizing wiring switching between the low-voltage side three-phase output circuit of the tested transformer and the simulation load resistance box;
the simulation load resistance box comprises at least three groups of resistors and is used for realizing three-phase star load connection or three-phase triangular load connection;
the three-phase collector is used for collecting three-phase current and voltage of the high-voltage side and the low-voltage side or the load side of the tested transformer;
the control device is an industrial personal computer or a single chip microcomputer, the test and control software is deployed on the industrial personal computer or an upper computer in communication connection with the control device, and the test and control software is used for setting the output frequency of the three-phase variable frequency test power supply and the sampling rate of the three-phase collector, controlling the information interaction between the control device and the three-phase collector, and processing and displaying the collected three-phase voltage and current;
the test cable insulation sheath device is sleeved outside a test cable connected with the high-voltage side and the low-voltage side of the tested transformer, the test cable insulation sheath device is of a three-layer structure, the outer layer is an insulation layer, the middle layer is a copper mesh, the inner layer is an insulation layer, the copper mesh is provided with conductor output ends on two edges of the cable insulation sheath, and the conductor output ends are directly grounded or grounded through a ground discharge loop;
the resistor in the analog load resistor box is a pure resistor, a capacitor resistor or an inductance composite impedance unit, the adjustable range of the capacitor is 0-10uF, and the adjustable range of the inductance is 0-100 mH;
the resistance values of the resistors in the analog load resistance box can be independently adjusted, and the adjustable range of the resistance values of the resistors is 0-500 ohms.
2. The transformer wiring fault testing device of claim 1, wherein the test cable insulating sheath device is a hollow round, a hollow square or other hole-shaped structure.
3. The transformer wiring fault testing device of claim 1, wherein the test cable insulating sheath device is a semi-open or telescopically fixed structure.
4. The transformer wiring fault testing device of claim 1, wherein the ground discharge circuit is a short circuit switch, a grounded copper wire, a resistor with ground, a resistor box with ground or a vacuum discharge gap module with ground.
5. The transformer wiring fault testing device of claim 1, wherein the adjustable range of the output frequency of the three-phase variable frequency test power supply is 10Hz-5kHz, and the adjustable range of the output voltage is 10V-600V.
6. The transformer wiring fault testing device of claim 1, wherein the low-voltage side wiring load combination switch realizes wiring switching through a knob manual mode or a numerical control mode.
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| CN201810355724.6A CN108535587B (en) | 2018-04-19 | 2018-04-19 | Transformer wiring fault testing device |
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| CN201810355724.6A CN108535587B (en) | 2018-04-19 | 2018-04-19 | Transformer wiring fault testing device |
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| CN108535587A CN108535587A (en) | 2018-09-14 |
| CN108535587B true CN108535587B (en) | 2021-05-14 |
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| CN112285616B (en) * | 2020-09-24 | 2022-05-06 | 国网河北省电力有限公司 | Method and device for rapidly judging internal fault of electrical equipment |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102096003A (en) * | 2009-12-15 | 2011-06-15 | 西安爱邦电气有限公司 | Automatic analytical device for checking wiring of conventional transformer |
| CN102095960A (en) * | 2009-12-15 | 2011-06-15 | 西安爱邦电气有限公司 | Device for checking wiring correctness of conventional transformer |
| CN102129006A (en) * | 2011-03-01 | 2011-07-20 | 宁波市鄞州供电局 | Method for detecting errors of differential protection secondary connection of microcomputer type transformer |
| CN102590564A (en) * | 2012-03-05 | 2012-07-18 | 天威云南变压器股份有限公司 | Wiring structure for partial discharge test of balance traction transformer |
| CN103248240A (en) * | 2013-04-11 | 2013-08-14 | 株洲变流技术国家工程研究中心有限公司 | Experimental power supply system for high-voltage electric pump |
| CN103698621B (en) * | 2013-09-05 | 2016-08-17 | 国家电网公司 | A kind of transformer vehicular integrated test system |
| CN203535143U (en) * | 2013-10-31 | 2014-04-09 | 国家电网公司 | A large transformer field test integrated apparatus based on a frequency-converting and voltage-adjusting power supply |
| CN106483341A (en) * | 2015-08-31 | 2017-03-08 | 国网山东莒南县供电公司 | Transformer detection wiring converter |
| CN105510645B (en) * | 2015-11-30 | 2018-09-07 | 杭州西湖电子研究所 | A kind of mode of connection of Integral three-phase power transformer automatic detection |
| CN105931771B (en) * | 2016-05-25 | 2018-07-20 | 江苏中鹏电气有限公司 | Shielding cylinder and its manufacture craft |
| CN205809149U (en) * | 2016-06-13 | 2016-12-14 | 国家电网公司 | Transformer iron core grounding current on-Line Monitor Device |
| CN106597158A (en) * | 2016-12-12 | 2017-04-26 | 上海欧秒电力监测设备有限公司 | Distribution transformer integrated detection device |
| CN107293198A (en) * | 2017-06-21 | 2017-10-24 | 柳州职业技术学院 | A kind of low-voltage power supply system fault diagnosis actual training device |
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