CN106526406A - Inter-tern short-circuit detection device, analysis method and device for voltage transformer - Google Patents

Abstract

The present invention provides a voltage transformer turn-to-turn short-circuit detection device, analysis method and device, wherein the analysis method includes: obtaining the voltage collected by the voltage transformer turn-to-turn short-circuit detection device, analyzing the voltage, and determining whether the voltage transformer to be tested is There is a turn-to-turn short circuit. The inter-turn short circuit detection device of the voltage transformer includes: an impulse voltage generator, a voltage transformer to be tested, a sampling resistor, and a voltage acquisition device; the impulse voltage generator is connected to the high-voltage end of the voltage transformer to be tested, and the low-voltage connected to one end of the sampling resistor, and the other end of the sampling resistor is grounded; the sampling resistor is connected in parallel with the voltage acquisition device; the impulse voltage generator is used to apply the generated impulse voltage to the voltage transformer to be measured; the voltage acquisition device is used to collect the two sampling resistors terminal voltage. The turn-to-turn short-circuit fault of the voltage transformer can be effectively detected by using the inter-turn short-circuit detection device of the voltage transformer and the inter-turn short-circuit analysis device of the voltage transformer.

Description

Inter-turn short circuit detection device, analysis method and device of voltage transformer

technical field

The invention relates to the technical field of electric power system relay protection, in particular to a detection device, an analysis method and a device for inter-turn short circuit of a voltage transformer.

Background technique

In recent years, there have been many short-circuit faults between turns of voltage transformers, which have greatly affected production and operation. For the inter-turn short circuit of a voltage transformer, the conventional detection methods are DC resistance detection, no-load current detection, triple frequency withstand voltage detection and transformation ratio detection. However, the above methods are difficult to completely determine inter-turn short circuit, and for voltage transformers with less serious inter-turn short circuit, it is difficult to find problems in DC resistance detection, no-load current detection and transformation ratio detection, and triple frequency withstand voltage detection is even more difficult. Due to the small voltage evenly distributed between the turns, it is sometimes difficult to find potential faults between the turns. Therefore, there is an urgent need to study new methods for detecting inter-turn short-circuit faults of voltage transformers to solve the above problems.

For the new detection method of inter-turn short circuit, researchers have proposed to input a voltage signal with variable frequency at the secondary coil, and measure the impedance at the same time. When the frequency is higher, the impedance change caused by inter-turn short circuit is more obvious. However, this method is basically in the stage of theoretical research, and it is difficult to obtain a frequency-variable voltage signal source that can generate high-voltage signals, and the cost is relatively high. Generally, the output voltage of a voltage signal source with adjustable frequency is generally less than 20kV.

Contents of the invention

An embodiment of the present invention provides a device for detecting a short circuit between turns of a voltage transformer, the device comprising: an impulse voltage generator, a voltage transformer to be tested, a sampling resistor, and a voltage acquisition device;

The impulse voltage generator is connected to the high-voltage end of the voltage transformer to be tested, the low-voltage end of the voltage transformer to be tested is connected to one end of the sampling resistor, and the other end of the sampling resistor is grounded; the sampling resistor is connected in parallel with the voltage acquisition device;

The impulse voltage generator is used to generate an impulse voltage, and apply the impulse voltage to the voltage transformer to be tested;

The voltage acquisition device is used to collect the voltage at both ends of the sampling resistor, and the voltage is used to analyze whether there is an inter-turn short circuit in the voltage transformer to be tested.

In one embodiment, the voltage acquisition device is an oscilloscope.

In one embodiment, it also includes: a protection device connected in parallel with the sampling resistor;

The protection device is used to protect the impulse voltage generator, the sampling resistor and the voltage acquisition device.

In one embodiment, the protection device is a discharge tube or other devices for suppressing voltage.

In one embodiment, it also includes: an impulse voltage divider;

One end of the impulse voltage divider is connected to the high-voltage end of the voltage transformer to be tested, and the other end of the impulse voltage divider is grounded;

The impulse voltage divider is used to measure the impulse voltage generated by the impulse voltage generator.

An embodiment of the present invention provides a method for analyzing a turn-to-turn short circuit of a voltage transformer, the method comprising: acquiring the voltage collected by the above-mentioned turn-to-turn short-circuit detection device of the voltage transformer;

Analyze the voltage to determine whether there is an inter-turn short circuit in the voltage transformer to be tested.

In one embodiment, the voltage is analyzed to determine whether there is an inter-turn short circuit in the voltage transformer to be tested, including:

Calculate the first correlation coefficient between the first voltage value and the second voltage value, the second correlation coefficient between the first voltage value and the third voltage value, and the third correlation coefficient between the first voltage value and the fourth voltage value, respectively. correlation coefficient;

The absolute value of the difference between the first correlation coefficient and the second correlation coefficient, the absolute value of the difference between the first correlation coefficient and the third correlation coefficient, and the absolute value of the difference between the second correlation coefficient and the third correlation coefficient The values are added to get the final value;

Comparing the final value with the preset standard value, when the final value is greater than the preset standard value, it is determined that there is an inter-turn short circuit in the voltage transformer to be tested; when the final value is smaller than the preset standard value, it is determined that the voltage transformer to be tested is qualified;

Wherein, the first voltage value is the voltage value at both ends of the sampling resistor collected in the first cycle after the impulse voltage generator applies the first impulse voltage to the voltage transformer to be tested; the second voltage value is the impulse voltage generator applying the first impulse voltage The voltage value at both ends of the sampling resistor collected in the second cycle after the impulse voltage is applied to the voltage transformer to be tested; The voltage value at both ends of the sampling resistance collected within; the fourth voltage value is the voltage value at both ends of the sampling resistance collected in the second cycle after the impulse voltage generator applies the second impulse voltage to the voltage transformer to be tested; The magnitude difference between the first impulse voltage and the second impulse voltage is half.

The embodiment of the present invention also provides an inter-turn short-circuit analysis device of a voltage transformer, which includes: an acquisition module for acquiring the voltage collected by the above-mentioned inter-turn short-circuit detection device of the voltage transformer;

The analysis module is used to analyze the voltage and determine whether there is an inter-turn short circuit in the voltage transformer to be tested.

In one embodiment, the analysis module is specifically used for:

Calculate the first correlation coefficient between the first voltage value and the second voltage value, the second correlation coefficient between the first voltage value and the third voltage value, and the third correlation coefficient between the first voltage value and the fourth voltage value, respectively. correlation coefficient;

The absolute value of the difference between the first correlation coefficient and the second correlation coefficient, the absolute value of the difference between the first correlation coefficient and the third correlation coefficient, and the absolute value of the difference between the second correlation coefficient and the third correlation coefficient The values are added to get the final value;

Comparing the final value with the preset standard value, when the final value is greater than the preset standard value, it is determined that there is an inter-turn short circuit in the voltage transformer to be tested; when the final value is smaller than the preset standard value, it is determined that the voltage transformer to be tested is qualified;

Wherein, the first voltage value is the voltage value at both ends of the sampling resistor collected in the first cycle after the impulse voltage generator applies the first impulse voltage to the voltage transformer to be tested; the second voltage value is the impulse voltage generator applying the first impulse voltage The voltage value at both ends of the sampling resistor collected in the second cycle after the impulse voltage is applied to the voltage transformer to be tested; The voltage value at both ends of the sampling resistance collected within; the fourth voltage value is the voltage value at both ends of the sampling resistance collected in the second cycle after the impulse voltage generator applies the second impulse voltage to the voltage transformer to be tested; The magnitude difference between the first impulse voltage and the second impulse voltage is half.

In the embodiment of the present invention, the impulse voltage is generated by the impulse voltage generator, and the impulse voltage is applied to the voltage transformer to be tested, and the voltage at both ends of the sampling resistor is collected by the voltage acquisition device, and the voltage is used to analyze the voltage transformer to be tested Whether there is a short circuit between turns. Compared with the existing inter-turn short-circuit detection device of voltage transformer, the inter-turn short-circuit detection device of voltage transformer of the present invention does not need to find a voltage signal source with variable frequency that can generate high-voltage signals, and the existing impulse voltage generator can be used Yes, cost savings.

The voltage collected by the turn-to-turn short-circuit detection device of the voltage transformer can be analyzed by adopting the method and device for analyzing the turn-to-turn short-circuit of the voltage transformer of the present invention, thereby effectively detecting the turn-to-turn short-circuit fault of the voltage transformer.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic structural diagram of a voltage transformer turn-to-turn short-circuit detection device provided by an embodiment of the present invention;

Fig. 2 is a structural schematic diagram II of a voltage transformer turn-to-turn short-circuit detection device provided by an embodiment of the present invention;

Fig. 3 is a flow chart of a method for analyzing a short circuit between turns of a voltage transformer provided by an embodiment of the present invention;

Fig. 4 is a schematic structural diagram of a voltage transformer turn-to-turn short-circuit analysis device provided by an embodiment of the present invention;

5 is a schematic structural diagram of a semi-insulated voltage transformer turn-to-turn short-circuit detection device provided by an embodiment of the present invention;

Fig. 6 is a first schematic diagram of the relationship between the correlation coefficient and the harmonic order provided by the embodiment of the present invention;

Fig. 7 is a schematic structural diagram of a fully insulated voltage transformer turn-to-turn short-circuit detection device provided by an embodiment of the present invention;

FIG. 8 is a second schematic diagram of the relationship between a correlation coefficient and a harmonic order provided by an embodiment of the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The reason why the inter-turn short circuit test method in the prior art cannot find potential inter-turn insulation hazards is that the voltage applied by DC resistance detection and no-load current detection is relatively low, and it is not easy to find that there is still a certain degree of insulation, but there are potential risks. The turn-to-turn insulation problem stems from the fact that the turn-to-turn insulation has not yet broken down during the experiment. Therefore, it is an effective means to try to use the operation impact equipment that can output a higher voltage level to detect the inter-turn insulation, which will break down the inter-turn insulation in an instant and reflect it on the curve. In addition, impedance and frequency are closely related (Z=2πf*L, Z impedance, f test frequency, L inductance). When the frequency increases, the change of impedance is more sensitive, and it is also helpful to find the change of impedance through comparative experiments. Thus finding the inter-turn insulation problem. Lightning impulse is a signal source covering a variety of frequency voltage signals. There are many high-frequency signals, which can effectively detect changes in impedance.

Based on this, the present invention proposes a voltage transformer turn-to-turn short circuit detection device, as shown in Figure 1, the device includes: an impulse voltage generator 1, a voltage transformer to be tested 2, a sampling resistor 3, and a voltage acquisition device 4;

The impulse voltage generator 1 is connected to the high-voltage end of the voltage transformer 2 to be tested, the low-voltage end of the voltage transformer 2 to be measured is connected to one end of the sampling resistor 3, and the other end of the sampling resistor 3 is grounded; the sampling resistor 3 is connected to the voltage acquisition device 4 parallel connection; wherein, the impulse voltage generator 1 is used to generate the impulse voltage, and the impulse voltage is applied to the voltage transformer 2 to be tested; the voltage acquisition device 4 is used to acquire the voltage at both ends of the sampling resistor 3, and the voltage is used for analyzing the Whether there is inter-turn short circuit in voltage transformer 2.

During specific implementation, the impulse voltage generator 1 is mainly used for impulse voltage tests of full-wave lightning impulse voltage, chopping wave of lightning impulse voltage and operation impulse voltage wave of electric equipment and other test products to test insulation performance. The voltage acquisition device 4 may be any kind of voltage acquisition device, such as a multimeter. The present invention uses an oscilloscope to collect the voltage across the sampling resistor 3 . The sampling resistor 3 is a non-inductance resistor.

During specific implementation, as shown in Figure 2, the inter-turn short circuit detection device of the voltage transformer of the present invention can also include: a protection device 5, connected in parallel with the sampling resistor 4, mainly used for the impulse voltage generator 1, the sampling resistor 3 and the voltage acquisition Device 4 protects. Specifically, the protection device 5 may use a discharge tube. The discharge tube is a high-voltage protection component used at the input end of the device. If the voltage at both ends is higher than its protection specification value, a short circuit will occur inside it and absorb the input overvoltage. The protection device 5 can also adopt any other equipment for suppressing voltage.

As shown in Figure 2, the inter-turn short circuit detection device of the voltage transformer of the present invention can also include: an impulse voltage divider 6; one end of the impulse voltage divider 6 is connected to the high voltage end of the voltage transformer 4 to be tested, and the impulse voltage divider The other end of the transformer 6 is grounded. The function of using the impulse voltage divider 6 is to quantitatively measure the impulse voltage generated by the impulse voltage generator 1, so as to prevent the impulse voltage generated by the impulse voltage generator 1 from being too large and damaging the voltage transformer 2 to be measured.

The turn-to-turn short-circuit detection device of a voltage transformer proposed by the invention is suitable for dry-type and solid-insulated voltage transformers, and its principle is generally an electromagnetic voltage transformer. The turn-to-turn insulation of medium-voltage transformer coils in CVT (Continuously Variable Transmission, capacitive voltage transformer) can also be detected by the device of the present invention.

During specific implementation, based on the inter-turn short circuit detection device of the voltage transformer, the present invention also proposes a method for diagnosing the insulation defect of the voltage transformer winding by using the transient voltage and current in the impulse voltage test. According to the half-wave and full-wave impact tests of voltage transformer windings, through the two pressurization processes under full voltage (full wave, that is, full amplitude) and under reduced voltage (half wave, that is, half amplitude), the corresponding period section is obtained. Voltage amplitude and phase angle waveforms and/or current amplitude and phase angle waveforms at different frequencies (lightning waves can be regarded as voltage signals of multiple frequencies), that is, part of the lightning impulse voltage and current is divided into a series of harmonics, using the longitudinal ratio Method (comparison under different voltage conditions of the same PT) and aspect ratio method (comparison of results of the same type of PT, voltage transformer, and Potentialtransformer under the same conditions) to analyze the harmonic voltage or current data of the corresponding segment, and construct a correlation discriminant function . The detection of the insulation defect and severity of the voltage transformer winding can be realized. It is also possible to diagnose whether there is insulation damage to windings that pass the impact test.

Specifically, the flow chart of the method for analyzing the inter-turn short circuit of the voltage transformer proposed by the present invention is shown in Figure 3, and the method includes:

Step 301: Obtain the voltage collected by the inter-turn short circuit detection device of the voltage transformer;

Step 302: Analyze the voltage to determine whether there is an inter-turn short circuit in the voltage transformer to be tested.

During specific implementation, when carrying out inter-turn short circuit detection and analysis experiments of voltage transformers, first the impulse voltage generator in the inter-turn short circuit detection device of voltage transformers generates the first impulse voltage, and the first impulse voltage is applied to the voltage to be measured After the transformer, the first voltage value at both ends of the sampling resistor is collected in the first cycle, and the second voltage value at both ends of the sampling resistor is collected in the second cycle. Then change the impulse voltage generator to generate the second impulse voltage, and then apply the second impulse voltage to the voltage transformer to be tested, collect the third voltage value at both ends of the sampling resistor in the first cycle, and collect the third voltage value in the second cycle The fourth voltage value across the sampling resistor. Wherein, the magnitude difference between the first impulse voltage and the second impulse voltage is half. For example, the first impulse voltage may be full voltage (full wave, ie full amplitude), and the second impulse voltage may be reduced voltage (half wave, ie half amplitude). The first period and the second period are artificially set, for example, the first period may be 0-50 microseconds after the impulse voltage is applied, and the second period may be 50-100 microseconds after the impulse voltage is applied.

Then, analyze the voltage according to the following method to determine whether there is an inter-turn short circuit in the voltage transformer to be tested:

Calculate the first correlation coefficient between the first voltage value and the second voltage value, the second correlation coefficient between the first voltage value and the third voltage value, and the third correlation coefficient between the first voltage value and the fourth voltage value, respectively. correlation coefficient;

The absolute value of the difference between the first correlation coefficient and the second correlation coefficient, the absolute value of the difference between the first correlation coefficient and the third correlation coefficient, and the absolute value of the difference between the second correlation coefficient and the third correlation coefficient The values are added to get the final value;

Comparing the final value with the preset standard value, when the final value is greater than the preset standard value, it is determined that there is an inter-turn short circuit in the voltage transformer to be tested; when the final value is smaller than the preset standard value, it is determined that the voltage transformer to be tested is qualified.

Among them, the preset standard value is obtained by naturalization through the same test of a large number of qualified PTs.

Based on the same inventive concept, an embodiment of the present invention also provides a device for analyzing a turn-to-turn short circuit of a voltage transformer, as described in the following embodiments. Since the problem-solving principle of the inter-turn short-circuit analysis device of voltage transformer is similar to the analysis method of inter-turn short-circuit of voltage transformer, the implementation of the inter-turn short-circuit analysis device of voltage transformer can refer to the implementation of the analysis method of inter-turn short-circuit of voltage transformer. I won't repeat them here. As used below, the term "unit" or "module" may be a combination of software and/or hardware that realizes a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementations in hardware, or a combination of software and hardware are also possible and contemplated.

Fig. 4 is a structural block diagram of a voltage transformer turn-to-turn short-circuit analysis device according to an embodiment of the present invention, as shown in Fig. 4 , including:

An acquisition module 402, configured to acquire the voltage collected by the turn-to-turn short circuit detection device of the voltage transformer;

The analysis module 404 is used to analyze the voltage to determine whether there is an inter-turn short circuit in the voltage transformer to be tested.

During specific implementation, the analysis module 404 is specifically used for:

Calculate the first correlation coefficient between the first voltage value and the second voltage value, the second correlation coefficient between the first voltage value and the third voltage value, and the third correlation coefficient between the first voltage value and the fourth voltage value, respectively. correlation coefficient;

The absolute value of the difference between the first correlation coefficient and the second correlation coefficient, the absolute value of the difference between the first correlation coefficient and the third correlation coefficient, and the absolute value of the difference between the second correlation coefficient and the third correlation coefficient The values are added to get the final value;

Comparing the final value with the preset standard value, when the final value is greater than the preset standard value, it is determined that there is an inter-turn short circuit in the voltage transformer to be tested; when the final value is smaller than the preset standard value, it is determined that the voltage transformer to be tested is qualified;

Wherein, the first voltage value is the voltage value at both ends of the sampling resistor collected in the first cycle after the impulse voltage generator applies the first impulse voltage to the voltage transformer to be tested; the second voltage value is the impulse voltage generator applying the first impulse voltage The voltage value at both ends of the sampling resistor collected in the second cycle after the impulse voltage is applied to the voltage transformer to be tested; The voltage value at both ends of the sampling resistance collected within; the fourth voltage value is the voltage value at both ends of the sampling resistance collected in the second cycle after the impulse voltage generator applies the second impulse voltage to the voltage transformer to be tested; The magnitude difference between the first impulse voltage and the second impulse voltage is half.

The device and method of the present invention will be described below through specific examples.

Embodiment one

The voltage transformer to be tested in the voltage transformer turn-to-turn short circuit detection device proposed by the present invention adopts a semi-insulated voltage transformer, and the test wiring is as shown in Figure 5:

The lightning impulse application point is located at the high-voltage end of the semi-insulated voltage transformer. The lead-out line from the N-terminal (high-voltage end) of the primary winding of the semi-insulated voltage transformer is connected in series with a non-inductive measuring resistor and then connected to the ground. The input end of the non-inductive measuring resistor is connected in parallel with a discharge tube. , the voltage signal at both ends of the non-inductive measuring resistor is collected by an oscilloscope. The semi-insulated voltage transformer and the ground terminal of the impact generating equipment are reliably grounded. The test and measurement equipment is protected by a discharge tube connected in parallel to the circuit.

Lightning impulses of different magnitudes are applied to the high-voltage end of the semi-insulated voltage transformer, and the lead-out line from the N-terminal of the semi-insulated voltage transformer is grounded after being connected in series with a non-inductive measuring resistor. Response voltage of voltage transformer under lightning impulse.

Test product: a semi-insulated voltage transformer with abnormal no-load, the model is JDZX16-15, and the no-load current is 4.26mA. Apply 20kv and 10kv lightning impulse voltages to them respectively, among which, the 20kv lightning impulse voltage is 100% of the impulse voltage, and the 10kv lightning impulse voltage is 50% of the impulse voltage. The voltage value at both ends of the non-inductively measuring resistor within 50-100 microseconds under 100% impulse voltage, the voltage value at both ends of the non-inductively measuring resistor within 0-50 microseconds under 50% impulse voltage, under 50% impulse voltage The voltage value at both ends of the resistance is non-inductively measured within 50-100 microseconds. Based on the voltage value collected in 0-50 microseconds under 100% impulse voltage, the voltage value collected in 0-50 microseconds under 50% impulse voltage and the voltage collected in 50-100 microseconds under 100% impulse voltage respectively Compared with the voltage value collected within 50-100 microseconds under 50% impulse voltage, the voltage value collected within 0-50 microseconds under 100% impulse voltage is compared with the voltage value collected within 0-50 microseconds under 50% impulse voltage The correlation coefficient A of the voltage value, the correlation coefficient B of the voltage value collected within 0-50 microseconds under 100% impulse voltage and the voltage value collected within 50-100 microseconds under 100% impulse voltage, 0 under 100% impulse voltage The correlation coefficient C between the voltage value collected in ~50 microseconds and the voltage value collected in 50 ~ 100 microseconds under 50% impulse voltage, and then the absolute value of the difference between A, B and C is superimposed and summed (for example, it can be |A-B|+|A-C|+|B-C|), if its value is greater than the predetermined standard value, it is determined that there is a problem with the test product (semi-insulated voltage transformer with abnormal no-load), if it is less than, the test product (no-load Abnormal semi-insulated voltage transformer) qualified.

Figure 6 is a schematic diagram of the relationship between the correlation coefficient and the number of harmonics. The solid line in the figure indicates the voltage value collected in 0-50 microseconds under 100% impulse voltage and the voltage collected in 0-50 microseconds under 50% impulse voltage The correlation coefficient of the value (called the first correlation coefficient), the dotted line indicates the correlation between the voltage value collected in 0-50 microseconds under 100% impulse voltage and the voltage value collected in 50-100 microseconds under 100% impulse voltage coefficient (called the second correlation coefficient), the dotted line represents the correlation coefficient between the voltage value collected in 0-50 microseconds under 100% impulse voltage and the voltage value collected in 50-100 microseconds under 50% impulse voltage ( It is called the third correlation coefficient), as can be seen from Figure 6, the correlation coefficients of the three curves are not significantly different. Therefore, according to the above fixed algorithm, the absolute value of the difference between the first correlation coefficient and the second correlation coefficient, the absolute value of the difference between the first correlation coefficient and the third correlation coefficient, the second correlation coefficient and the third correlation coefficient The absolute values of the differences of the correlation coefficients are added to obtain a final value of 480, which is smaller than the preset standard value of 500, indicating that the test product shown in Figure 6 has no inter-turn short circuit defect.

Embodiment two

The voltage transformer to be tested in the voltage transformer turn-to-turn short circuit detection device proposed by the present invention adopts a fully insulated voltage transformer, and the test wiring is as shown in Figure 7:

The lightning impulse application point is located at one end of the high-voltage winding of the fully-insulated voltage transformer. The lead-out line from the other end of the high-voltage winding of the fully-insulated voltage transformer is connected in series with a non-inductive measuring resistor and then connected to the ground. The input end of the non-inductive measuring resistor is connected in parallel with a discharge tube. The voltage signal at both ends of the non-inductive measuring resistor is collected. The fully insulated voltage transformer and the ground terminal of the impulse voltage generating equipment are reliably grounded.

Test product: fully insulated voltage transformer with abnormal no-load, model JDZX16-15, no-load current 4.26mA. Apply 20kv and 10kv lightning impulse voltage to them respectively, collect the voltage value at both ends of the non-inductive measurement resistor within 0-50 microseconds under 100% impulse voltage, and the voltage at both ends of the non-inductive measurement resistance within 50-100 microseconds under 100% impulse voltage Value, the voltage value at both ends of the non-inductive measurement resistor within 0-50 microseconds under 50% impulse voltage, and the voltage value at both ends of the non-inductive measurement resistance within 50-100 microseconds under 50% impulse voltage. Based on the voltage value collected in 0-50 microseconds under 50% impulse voltage, it is respectively compared with the voltage value collected in 0-50 microseconds under 100% impulse voltage and the voltage collected in 50-100 microseconds under 50% impulse voltage Compared with the voltage value collected in 50-100 microseconds under 100% impulse voltage, the voltage value collected in 0-50 microseconds under 50% impulse voltage is compared with the voltage value collected in 0-50 microseconds under 100% impulse voltage Correlation coefficient A of voltage value, correlation coefficient B of voltage value collected within 0-50 microseconds under 50% impulse voltage and voltage value collected within 50-100 microseconds under 50% impulse voltage, 0 under 50% impulse voltage The correlation coefficient C between the voltage value collected in ~50 microseconds and the voltage value collected in 50 ~ 100 microseconds under 100% impulse voltage, and then the absolute value of the difference between A, B and C is superimposed and summed (for example, it can be |A-B|+|A-C|+|B-C|), if its value is greater than the predetermined standard value, it is determined that there is a problem with the test product (semi-insulated voltage transformer with abnormal no-load), if it is less than, the test product (no-load Abnormal semi-insulated voltage transformer) qualified.

Figure 8 is a schematic diagram of the relationship between the correlation coefficient and the number of harmonics. The solid line in the figure indicates the voltage value collected in 0-50 microseconds under 50% impulse voltage and the voltage collected in 0-50 microseconds under 100% impulse voltage The correlation coefficient of the value (called the second correlation coefficient), the dotted line indicates the correlation between the voltage value collected in 0-50 microseconds under 50% impulse voltage and the voltage value collected in 50-100 microseconds under 50% impulse voltage coefficient (called the first correlation coefficient), the dotted line represents the correlation coefficient between the voltage value collected in 0-50 microseconds under 50% impulse voltage and the voltage value collected in 50-100 microseconds under 100% impulse voltage ( It is called the third correlation coefficient), as can be seen from Figure 8, the correlation coefficients of the three curves are not significantly different. Therefore, according to the above fixed algorithm, the absolute value of the difference between the first correlation coefficient and the second correlation coefficient, the absolute value of the difference between the first correlation coefficient and the third correlation coefficient, the second correlation coefficient and the third correlation coefficient The absolute value of the difference of the correlation coefficient is added to obtain a final value of 2000, and the final value is compared with the preset standard value, and the final value of 2000 is much greater than the preset standard value of 500, which can indicate that the test product shown in Figure 8 has an inter-turn short circuit defect.

In summary, when adopting the inter-turn short-circuit detection device, analysis method and device of the present invention to carry out the inter-turn short-circuit detection and analysis test of voltage transformers, the information of existing experiments can be fully utilized, which is helpful for voltage transformers. Rapid detection of insulation defects and reliability of detection. Research will be carried out around the detection method of inter-turn short circuit, and the test items corresponding to the research results will be directly applied to the handover or diagnostic test of electromagnetic voltage transformers.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, systems, or computer program products. Accordingly, the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, various modifications and changes may be made to the embodiments of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (9)

1. A voltage transformer turn-to-turn short-circuit detection device, characterized in that it comprises: an impulse voltage generator, a voltage transformer to be measured, a sampling resistor, and a voltage acquisition device; The impulse voltage generator is connected to the high-voltage end of the voltage transformer to be tested, the low-voltage end of the voltage transformer to be tested is connected to one end of the sampling resistor, and the other end of the sampling resistor is grounded; the sampling resistor is connected in parallel with the voltage acquisition device; The impulse voltage generator is used to generate an impulse voltage, and apply the impulse voltage to the voltage transformer to be tested; The voltage acquisition device is used to collect the voltage at both ends of the sampling resistor, and the voltage is used to analyze whether there is an inter-turn short circuit in the voltage transformer to be tested. 2. The inter-turn short circuit detection device of a voltage transformer according to claim 1, wherein the voltage acquisition device is an oscilloscope. 3. The voltage transformer turn-to-turn short circuit detection device as claimed in claim 1, is characterized in that, also comprises: protection device, described protection device is connected in parallel with sampling resistance; The protection device is used to protect the impulse voltage generator, the sampling resistor and the voltage acquisition device. 4. The inter-turn short circuit detection device of a voltage transformer according to claim 3, wherein the protection device is a discharge tube or other voltage suppression equipment. 5. The voltage transformer turn-to-turn short circuit detection device as claimed in claim 1, further comprising: an impulse voltage divider; One end of the impulse voltage divider is connected to the high-voltage end of the voltage transformer to be tested, and the other end of the impulse voltage divider is grounded; The impulse voltage divider is used to measure the impulse voltage generated by the impulse voltage generator. 6. A method for analyzing a short circuit between turns of a voltage transformer, characterized in that it comprises: Obtaining the voltage collected by the inter-turn short circuit detection device of a voltage transformer according to any one of claims 1 to 5; Analyze the voltage to determine whether there is an inter-turn short circuit in the voltage transformer to be tested. 7. the voltage transformer turn-to-turn short-circuit analysis method as claimed in claim 6, is characterized in that, voltage is analyzed, determines whether there is turn-to-turn short-circuit in voltage transformer to be tested, comprises: Calculate the first correlation coefficient between the first voltage value and the second voltage value, the second correlation coefficient between the first voltage value and the third voltage value, and the third correlation coefficient between the first voltage value and the fourth voltage value, respectively. correlation coefficient; The absolute value of the difference between the first correlation coefficient and the second correlation coefficient, the absolute value of the difference between the first correlation coefficient and the third correlation coefficient, and the absolute value of the difference between the second correlation coefficient and the third correlation coefficient The values are added to get the final value; Comparing the final value with the preset standard value, when the final value is greater than the preset standard value, it is determined that there is an inter-turn short circuit in the voltage transformer to be tested; when the final value is smaller than the preset standard value, it is determined that the voltage transformer to be tested is qualified; Wherein, the first voltage value is the voltage value at both ends of the sampling resistor collected in the first cycle after the impulse voltage generator applies the first impulse voltage to the voltage transformer to be tested; the second voltage value is the impulse voltage generator applying the first impulse voltage The voltage value at both ends of the sampling resistor collected in the second period after the impulse voltage is applied to the voltage transformer to be tested; the third voltage value is the first period after the impulse voltage generator applies the second impulse voltage to the voltage transformer to be tested The voltage value at both ends of the sampling resistance collected within; the fourth voltage value is the voltage value at both ends of the sampling resistance collected in the second cycle after the impulse voltage generator applies the second impulse voltage to the voltage transformer to be tested; The magnitude difference between the first impulse voltage and the second impulse voltage is half. 8. A voltage transformer turn-to-turn short-circuit analysis device, characterized in that it comprises: An acquisition module, configured to acquire the voltage collected by the turn-to-turn short circuit detection device of a voltage transformer according to any one of claims 1 to 5; The analysis module is used to analyze the voltage and determine whether there is an inter-turn short circuit in the voltage transformer to be tested. 9. The voltage transformer turn-to-turn short-circuit analysis device as claimed in claim 8, wherein said analysis module is specifically used for: Calculate the first correlation coefficient between the first voltage value and the second voltage value, the second correlation coefficient between the first voltage value and the third voltage value, and the third correlation coefficient between the first voltage value and the fourth voltage value, respectively. correlation coefficient; The absolute value of the difference between the first correlation coefficient and the second correlation coefficient, the absolute value of the difference between the first correlation coefficient and the third correlation coefficient, and the absolute value of the difference between the second correlation coefficient and the third correlation coefficient The values are added to get the final value; Comparing the final value with the preset standard value, when the final value is greater than the preset standard value, it is determined that there is an inter-turn short circuit in the voltage transformer to be tested; when the final value is smaller than the preset standard value, it is determined that the voltage transformer to be tested is qualified; Wherein, the first voltage value is the voltage value at both ends of the sampling resistor collected in the first cycle after the impulse voltage generator applies the first impulse voltage to the voltage transformer to be tested; the second voltage value is the impulse voltage generator applying the first impulse voltage The voltage value at both ends of the sampling resistor collected in the second cycle after the impulse voltage is applied to the voltage transformer to be tested; The voltage value at both ends of the sampling resistance collected within; the fourth voltage value is the voltage value at both ends of the sampling resistance collected in the second cycle after the impulse voltage generator applies the second impulse voltage to the voltage transformer to be tested; The magnitude difference between the first impulse voltage and the second impulse voltage is half.