A main transformer winding resistance testing device

Abstract

The utility model discloses a main transformer winding resistance test equipment, including with core control module electricity connection's intelligent test module, magnetic flux compensation module, adaptive polishing module, heating module, adaptive protection module and multimode storage printing module, the connection method identification unit in intelligent test module identifies the wiring method of main transformer winding, neutral point dynamic correction unit corrects neutral point error, and high voltage test unit or low voltage test unit carries out direct current resistance test to main transformer winding, adaptive polishing module measures the wear degree and sets polishing parameter, and heating module executes electric heating. Thus, real -time dynamic magnetic flux compensation and neutral point correction are carried out to main transformer winding, and electric heating is carried out to the equipment itself, and the pre -polishing detection is carried out to main transformer winding, and the wear degree is measured and is set polishing parameter automatically according to this, so that the measurement data accuracy improves greatly, and the response is quick, is applicable to low temperature and various environments.

Description

Technical Field

[0001] This utility model relates to the field of power equipment testing technology, and in particular to a main transformer winding resistance testing device. Background Technology

[0002] Main transformer winding resistance testing is a key testing item in the power industry, which is directly related to the safe and stable operation of main transformer equipment. Existing DC resistance testers for main transformer equipment have basic single-phase / three-phase testing, tap changer grinding, and data storage functions.

[0003] However, in actual use, the residual magnetic flux after the main transformer winding test will affect the accuracy of subsequent test data. Existing DC resistance testers only perform simple demagnetization, but cannot detect and dynamically compensate for the magnetic flux in real time, resulting in large deviations in multiple measurement data. In addition, existing DC resistance testers do not consider the performance impact of low temperature environment on electronic components, resulting in problems such as measurement data drift and slow button response.

[0004] In addition, the tap changer grinding parameters (such as current, duration, number of cycles, etc.) of existing DC resistance testers need to be set manually, the wiring method of the main transformer winding needs to be judged manually, and the neutral point calibration is only a fixed manual procedure without a dynamic correction mechanism, making it difficult to meet the requirements for test accuracy and equipment environmental adaptability. Utility Model Content

[0005] This embodiment discloses a main transformer winding resistance testing device, specifically including: The intelligent testing module, magnetic flux compensation module, adaptive polishing module, heating module, adaptive protection module, and multi-mode storage and printing module are electrically connected to the core control module. The intelligent testing module includes a high-voltage testing unit, a low-voltage testing unit, a connection identification unit, and a neutral point dynamic correction unit. The magnetic flux compensation module includes a magnetic flux detection unit and a compensation output unit; The adaptive polishing module includes a wear detection unit and a polishing parameter adjustment unit; The heating module includes a temperature detection unit electrically connected to the temperature control unit, a heating unit, and an overheat protection unit; The adaptive protection module includes a back EMF protection unit, a wire breakage protection unit, an overcurrent protection unit, and a power failure protection unit. The multi-mode storage and printing module includes a data encryption unit, a local storage unit, a mobile storage unit, and a printing unit; Based on the drive commands output by the core control module, the connection identification unit in the intelligent test module identifies the connection method of the main transformer winding, the neutral point dynamic correction unit corrects the neutral point error in real time, and the high voltage test unit or the low voltage test unit performs DC resistance testing on the main transformer winding. Alternatively, based on the drive command output by the core control module, the wear detection unit in the adaptive grinding module measures the wear degree according to the change in the contact resistance of the tap switch, and the grinding parameter adjustment unit sets the grinding parameters based on the wear degree. The polishing parameters include at least the polishing current value, shift time, and number of cycles; The temperature control unit in the heating module is used to drive the heating unit to perform electric heating when the temperature detection unit detects that the current ambient temperature is lower than the detection temperature threshold.

[0006] In this embodiment, the core control module includes a data processing unit and a drive control unit; The data processing unit is used to accept externally input control commands and convert the control commands into drive commands; The drive control unit drives the intelligent testing module, the magnetic flux compensation module, the adaptive grinding module, the heating module, or the multi-mode storage and printing module to operate based on the drive command.

[0007] In this embodiment, the high-voltage testing unit includes several high-voltage clamps clamped to the high-voltage side bushing of the main transformer winding, and the low-voltage testing unit includes several low-voltage clamps clamped to the low-voltage side bushing of the main transformer winding.

[0008] In this embodiment, the high-voltage test unit or the low-voltage test unit outputs a 20A test current to perform a DC resistance test on the main transformer winding based on the wiring method and material properties of the main transformer winding identified by the connection identification unit.

[0009] In this embodiment, the neutral point dynamic correction unit is used to collect single-phase current parameters when performing a single-phase test on the main transformer winding, or to collect three-phase current parameters when performing a three-phase test on the main transformer winding, and to perform neutral point dynamic correction based on the difference between the single-phase current parameters or the three-phase current parameters and the standard current parameters.

[0010] In this embodiment, the magnetic flux detection unit in the magnetic flux compensation module is used to determine the initial magnetic flux in a DC resistance test using a Hall effect sensor. The compensation output unit is used to output a reverse compensation current to the main transformer winding based on the initial magnetic flux and the standard magnetic flux.

[0011] In this embodiment, the heating module is used to measure the current ambient temperature by the temperature detection unit before performing the DC resistance test, and the temperature control unit drives the heating unit to perform electric heating based on the current ambient temperature so that the entire device is heated to the normal operating temperature; The overheat protection unit is used to control the heating unit to stop electric heating when the entire equipment overheats.

[0012] In this embodiment, the wear detection unit in the adaptive polishing module is used to perform three pre-polishing operations on the disassembly switch and record the resistance change. The grinding parameter adjustment unit sets the corresponding grinding parameters according to the threshold range in which the resistance change falls.

[0013] In this embodiment, the back electromotive force protection unit in the adaptive protection module is used to clamp the voltage of the TVS transient suppression diode at the instant when the main transformer winding test power failure generates a back electromotive force, while the relay cuts off the test circuit. The disconnection protection unit is used to monitor the current value of the test circuit in real time and output a disconnection alarm when a power failure is detected. The overcurrent protection unit is used to cut off the power supply to the main transformer winding when the measured current is too large; The power failure protection unit is used to store the current test data when power is lost and to reset the test data after power is restored.

[0014] In this embodiment, the data encryption unit in the multi-mode storage printing module is used to perform data encryption on the test data; The local storage unit is used to store test data on a local storage medium; The mobile storage unit is used to store test data on a mobile storage medium; The printing unit is a thermal printing device used to print out test data.

[0015] Compared with the prior art, this embodiment has the following beneficial effects: In this embodiment, real-time dynamic magnetic flux compensation and neutral point correction are performed on the main transformer winding, and electric heating is applied to the equipment itself. Pre-grinding detection is also performed on the main transformer winding to measure the wear degree and automatically set the grinding parameters accordingly. This greatly improves the accuracy of the measurement data, provides a rapid response, and is suitable for various environments such as low temperature. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this embodiment, the accompanying drawings used in the embodiment will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the system structure of a main transformer winding resistance testing device disclosed in this embodiment. Detailed Implementation

[0018] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] Please see Figure 1 This embodiment discloses a main transformer winding resistance testing device, comprising: The intelligent testing module, magnetic flux compensation module, adaptive polishing module, heating module, adaptive protection module, and multi-mode storage and printing module are electrically connected to the core control module. The intelligent testing module includes a high-voltage testing unit, a low-voltage testing unit, a connection identification unit, and a neutral point dynamic correction unit; The magnetic flux compensation module includes a magnetic flux detection unit and a compensation output unit; The adaptive grinding module includes a wear detection unit and a grinding parameter adjustment unit; The heating module includes a temperature detection unit electrically connected to the temperature control unit, a heating unit, and an overheat protection unit; The adaptive protection module includes a back EMF protection unit, a line break protection unit, an overcurrent protection unit, and a power failure protection unit; The multi-mode storage and printing module includes a data encryption unit, a local storage unit, a mobile storage unit, and a printing unit; Based on the drive commands output by the core control module, the connection identification unit in the intelligent test module identifies the connection method of the main transformer winding, the neutral point dynamic correction unit corrects the neutral point error in real time, and the high voltage test unit or low voltage test unit performs DC resistance test on the main transformer winding. Alternatively, based on the drive commands output by the core control module, the wear detection unit in the adaptive grinding module measures the wear degree according to the change in the contact resistance of the tap changer, and the grinding parameter adjustment unit sets the grinding parameters based on the wear degree. Among them, the grinding parameters include at least the grinding current value, shift time and number of cycles; The temperature control unit in the heating module is used to drive the heating unit to perform electric heating when the temperature detection unit detects that the current ambient temperature is lower than the detection temperature threshold.

[0020] In this embodiment, real-time dynamic magnetic flux compensation and neutral point correction are performed on the main transformer winding, and electric heating is applied to the equipment itself. Pre-grinding detection is also performed on the main transformer winding to measure the wear degree and automatically set the grinding parameters accordingly. This greatly improves the accuracy of the measurement data, provides a rapid response, and is suitable for various environments such as low temperature.

[0021] In this embodiment, the core control module includes a data processing unit and a drive control unit; The data processing unit is used to accept externally input control commands and convert the control commands into drive commands; The drive control unit drives the intelligent testing module, magnetic flux compensation module, adaptive grinding module, heating module, or multi-mode storage and printing module based on drive commands.

[0022] Here, the core control module is used to receive control commands and convert drive commands.

[0023] The control commands can be input via buttons. For example, when a user presses the "Switch Grinding" button, the core control module obtains the control command corresponding to the switch grinding test function, converts it into a drive command, and transmits it to the adaptive grinding module.

[0024] In this embodiment, the high-voltage testing unit includes several high-voltage clamps clamped to the high-voltage side bushing of the main transformer winding, and the low-voltage testing unit includes several low-voltage clamps clamped to the low-voltage side bushing of the main transformer winding.

[0025] In this embodiment, the high-voltage test unit or the low-voltage test unit outputs a 20A test current to perform a DC resistance test on the main transformer winding based on the wiring method and material properties of the main transformer winding identified by the connection identification unit.

[0026] Here, when performing DC resistance testing, first clamp the high-voltage clamp or low-voltage clamp to the corresponding bushing of the main transformer winding, and then input the test number, main transformer winding material, calculated temperature, and the wiring method identified by the connection identification unit, and then test the output 20A test current of the main transformer winding.

[0027] In this embodiment, the neutral point dynamic correction unit is used to collect single-phase current parameters when performing a single-phase test on the main transformer winding, or to collect three-phase current parameters when performing a three-phase test on the main transformer winding, and to perform neutral point dynamic correction based on the difference between the single-phase current parameters or the three-phase current parameters and the standard current parameters.

[0028] Here, dynamic parameters are obtained based on the current parameters collected, thereby ensuring that the deviation between single-phase current parameters and three-phase current parameters is ≤2%.

[0029] In this embodiment, the magnetic flux detection unit in the magnetic flux compensation module is used to determine the initial magnetic flux in the DC resistance test by means of a Hall effect sensor. The compensation output unit is used to output a reverse compensation current to the main transformer winding based on the initial magnetic flux and the standard magnetic flux.

[0030] Here, compared to conventional demagnetization operations, by measuring the magnetic flux and performing active compensation, the measurement error caused by magnetic flux deviation is effectively eliminated, and good measurement conditions are obtained.

[0031] In this embodiment, the heating module is used to measure the current ambient temperature by the temperature detection unit before performing the DC resistance test. The temperature control unit drives the heating unit to perform electric heating based on the current ambient temperature so that the entire device is heated to the normal operating temperature. The overheat protection unit is used to control the heating unit to stop electric heating when the entire equipment overheats.

[0032] Here, by heating the device body, the electronic components are kept at an ideal operating temperature, effectively improving measurement accuracy.

[0033] In this embodiment, the wear detection unit in the adaptive polishing module is used to perform three pre-polishing operations on the disassembly switch and record the resistance change. The grinding parameter adjustment unit sets the corresponding grinding parameters based on the threshold range of the resistance change.

[0034] Here, the change in resistance can be used to measure the wear of the tap changer.

[0035] For example, if 5% < resistance change ≤ 10%, then the tap changer surface is considered to be slightly oxidized. If 10% < resistance change ≤ 15%, the tap changer is judged to be slightly deformed. If 15% < the change in resistance, the tap changer is determined to be severely deformed or severely oxidized.

[0036] Accordingly, for tap switches with slight surface oxidation, an 80% polishing current, a 1000ms shifting time, and 5 cycles can be set; for tap switches with slight deformation, a 90% polishing current, an 800ms shifting time, and 8 cycles can be set; and for tap switches with severe deformation or severe surface oxidation, a 100% polishing current, a 600ms shifting time, and 12 cycles can be set.

[0037] Therefore, the polishing process is not affected by subjective human judgment, which can ensure that polishing is efficient and accurate.

[0038] In this embodiment, the back EMF protection unit in the adaptive protection module is used to clamp the voltage of the TVS transient suppression diode at the instant when the main transformer winding test power failure generates a back EMF, while the relay cuts off the test circuit. The disconnection protection unit is used to monitor the current value of the test circuit in real time and output a disconnection alarm when a power failure is detected. The overcurrent protection unit is used to cut off the power supply to the main transformer winding when the measured current is too high; The power failure protection unit is used to store the current test data when power is lost and to reset the test data after power is restored.

[0039] Here, by setting protective measures for each node, we ensure that no accidents occur during the testing process and that the main transformer windings are not damaged.

[0040] In this embodiment, the data encryption unit in the multi-mode storage printing module is used to perform data encryption on the test data; The local storage unit is used to store test data on the local storage medium; The mobile storage unit is used to store test data on a mobile storage medium; The printing unit is a thermal printer used to print out test data.

[0041] Here, data can be securely backed up and easily accessed through local and mobile storage media, and current test data can be viewed intuitively through printing.

[0042] Compared with the prior art, this embodiment has the following beneficial effects: In this embodiment, real-time dynamic magnetic flux compensation and neutral point correction are performed on the main transformer winding, and electric heating is applied to the equipment itself. Pre-grinding detection is also performed on the main transformer winding to measure the wear degree and automatically set the grinding parameters accordingly. This greatly improves the accuracy of the measurement data, provides a rapid response, and is suitable for various environments such as low temperature.

Claims

1. A device for testing the resistance of a main transformer winding, characterized in that, include: The intelligent testing module, magnetic flux compensation module, adaptive polishing module, heating module, adaptive protection module, and multi-mode storage and printing module are electrically connected to the core control module. The intelligent testing module includes a high-voltage testing unit, a low-voltage testing unit, a connection identification unit, and a neutral point dynamic correction unit. The magnetic flux compensation module includes a magnetic flux detection unit and a compensation output unit; The adaptive polishing module includes a wear detection unit and a polishing parameter adjustment unit; The heating module includes a temperature detection unit electrically connected to the temperature control unit, a heating unit, and an overheat protection unit; The adaptive protection module includes a back EMF protection unit, a wire breakage protection unit, an overcurrent protection unit, and a power failure protection unit. The multi-mode storage and printing module includes a data encryption unit, a local storage unit, a mobile storage unit, and a printing unit; Based on the drive commands output by the core control module, the connection identification unit in the intelligent test module identifies the connection method of the main transformer winding, the neutral point dynamic correction unit corrects the neutral point error in real time, and the high voltage test unit or the low voltage test unit performs DC resistance testing on the main transformer winding. Alternatively, based on the drive command output by the core control module, the wear detection unit in the adaptive grinding module measures the wear degree according to the change in the contact resistance of the tap switch, and the grinding parameter adjustment unit sets the grinding parameters based on the wear degree. The polishing parameters include at least the polishing current value, shift time, and number of cycles; The temperature control unit in the heating module is used to drive the heating unit to perform electric heating when the temperature detection unit detects that the current ambient temperature is lower than the detection temperature threshold.

2. The main transformer winding resistance testing device according to claim 1, characterized in that, include: The core control module includes a data processing unit and a drive control unit; The data processing unit is used to accept externally input control commands and convert the control commands into drive commands; The drive control unit drives the intelligent testing module, the magnetic flux compensation module, the adaptive grinding module, the heating module, or the multi-mode storage and printing module to operate based on the drive command.

3. The main transformer winding resistance testing device according to claim 1, characterized in that, include: The high-voltage testing unit includes several high-voltage clamps clamped to the high-voltage side bushing of the main transformer winding, and the low-voltage testing unit includes several low-voltage clamps clamped to the low-voltage side bushing of the main transformer winding.

4. The main transformer winding resistance testing device according to claim 3, characterized in that, include: The high-voltage test unit or the low-voltage test unit outputs a 20A test current to perform a DC resistance test on the main transformer winding based on the wiring method and material properties of the main transformer winding identified by the connection identification unit.

5. The main transformer winding resistance testing device according to claim 3, characterized in that, include: The neutral point dynamic correction unit is used to collect single-phase current parameters when performing a single-phase test on the main transformer winding, or to collect three-phase current parameters when performing a three-phase test on the main transformer winding, and to perform neutral point dynamic correction based on the difference between the single-phase current parameters or the three-phase current parameters and the standard current parameters.

6. The main transformer winding resistance testing device according to claim 4, characterized in that, include: The magnetic flux detection unit in the magnetic flux compensation module is used to determine the initial magnetic flux in a DC resistance test using a Hall effect sensor. The compensation output unit is used to output a reverse compensation current to the main transformer winding based on the initial magnetic flux and the standard magnetic flux.

7. The main transformer winding resistance testing device according to claim 6, characterized in that, include: The heating module is used to measure the current ambient temperature by the temperature detection unit before performing the DC resistance test. The temperature control unit drives the heating unit to perform electric heating based on the current ambient temperature so that the entire device is heated to the normal operating temperature. The overheat protection unit is used to control the heating unit to stop electric heating when the entire equipment overheats.

8. The main transformer winding resistance testing device according to claim 1, characterized in that, include: The wear detection unit in the adaptive polishing module is used to perform three pre-polishing operations on the disassembly switch and record the resistance change. The grinding parameter adjustment unit sets the corresponding grinding parameters according to the threshold range in which the resistance change falls.

9. The main transformer winding resistance testing device according to claim 1, characterized in that, include: The back EMF protection unit in the adaptive protection module is used to clamp the voltage of the TVS transient suppression diode at the instant when the main transformer winding test power failure generates a back EMF, while the relay cuts off the test circuit. The disconnection protection unit is used to monitor the current value of the test circuit in real time and output a disconnection alarm when a power failure is detected. The overcurrent protection unit is used to cut off the power supply to the main transformer winding when the measured current is too large; The power failure protection unit is used to store the current test data when power is lost and to reset the test data after power is restored.

10. The main transformer winding resistance testing device according to claim 1, characterized in that, include: The data encryption unit in the multi-mode storage printing module is used to perform data encryption on the test data; The local storage unit is used to store test data on a local storage medium; The mobile storage unit is used to store test data on a mobile storage medium; The printing unit is a thermal printing device used to print out test data.

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