Method for measuring creepage distance by using positioning gasket

Abstract

The invention discloses a method for measuring a creepage distance by using a positioning gasket, a base (1) and two locking devices (2) form a U-shaped groove, a motor stator iron core groove is simulated, the size of the U-shaped groove is # imgabs0, a copper bar (4) is placed at the bottom of the U-shaped groove, the size of the copper bar is matched with that of the U-shaped groove, the positioning gasket (5) is placed above the copper bar, and the positioning gasket (5) is placed in the U-shaped groove. During measurement, according to a test voltage, positioning gaskets (5) of two specifications are combined to be 20mm high, and an electrode locking device (3) is placed above the positioning gaskets (5). According to the invention, repeated utilization of the positioning gasket can be ensured, the thickness of the gasket can be directly adapted for measurement of different voltage grades, re-customization is not needed, the thickness of the positioning gasket is equal to the creepage distance, the creepage trace of the positioning gasket is the creepage path, and the creepage distances under different voltage grades can be accurately and conveniently measured.

Description

Technical field:

[0001] The invention relates to a method for measuring creepage distance by using a positioning gasket. Background technology:

[0002] With the development of the electrical industry, high-voltage motors are increasingly widely used, and high voltage means higher insulation requirements. Whether the motor is in no-load or running state, it is a live body. There are different potentials between the motor windings and adjacent components and grounded components. The surface of the winding insulation is often at a high potential, especially when the voltage is withstand and the potential of the winding insulation surface is higher when it encounters overvoltage attack. In order to prevent discharge or creepage between windings and other parts, there should be a certain creepage distance between them. The shortest distance between two adjacent conductors or a conductor and the winding insulation is the creepage distance; different detection methods also have different requirements for creepage distance. In the current technology, gauges or rulers are often used to measure different creepage distances, but the creepage distance and creepage path under different voltage levels cannot be directly presented; there is also an adjustable plug gauge that can measure the creepage distance, but plug gauges of different sizes need to be customized after each use, and the measuring device is cumbersome and inconvenient to operate.

[0003] The present invention provides a tooling process for measuring creepage distance, wherein a U-shaped groove simulates a stator slot of a motor, and a polyimide film is attached to the inside of the U-shaped groove itself, so that the U-shaped groove can be reused. For different voltage levels, measurement is performed by adapting the thickness of a positioning gasket, and the creepage distance can be intuitively measured by the thickness of the positioning gasket, and the creepage trace of the positioning gasket itself is the creepage path. The present invention can accurately and conveniently measure the creepage distance under different voltage levels. Summary of the invention:

[0004] The purpose of the present invention is to provide a method for measuring creepage distance using a positioning gasket, which can replace the polyimide film adhesive tape, ensure a stable operating environment, reduce the interference of leakage current, and ensure the accuracy of measurement data. The technical solution of the present invention is: a method for measuring creepage distance using a positioning gasket, step 1, a base (1) and two locking devices (2) form a U-shaped groove, simulating the stator core slot of a motor, the U-shaped groove size: 25.40 +0.1 ×50×200mm;

[0005] Step 2, a copper bar (4) is placed at the bottom of the U-shaped groove, the size of the copper bar is adapted to the size of the U-shaped groove, and a positioning gasket (5) is placed above the copper bar. When measuring, two sizes of positioning gaskets (5) are first combined into a 20 mm high according to the test voltage, and an electrode locking device (3) is placed above the positioning gasket (5);

[0006] Step 3, the electrode locking device (3) is made of a copper bar, and is divided into a locking device (3) and a positioning copper bar (6). The locking device (3) is connected to the high-voltage line of the high-voltage test transformer with a lead wire. The positioning copper bar (6) is consistent in width with the positioning gasket (5) and has a height of 10 mm and 20 mm, and is used to lock the positioning gasket (5). The high-voltage test transformer applies a power frequency voltage between the electrode locking device (3) and the copper bar (4). During the step-up process, when creepage occurs, the voltage at this time is recorded and the test is stopped. The voltage value at this time is the creepage voltage.

[0007] Step 4, after discharging, remove the locking device (3) and the positioning copper strip (6), and measure the thickness of the positioning gasket (5), which is the creepage distance under the measurement voltage;

[0008] Step 5, after the above preliminary test is completed, check the creepage path on the surface of the positioning gasket (5), and repeat the above test according to the distance of the creepage path. The thickness of the positioning gasket (5) is increased or decreased according to the creepage path to further verify the creepage distance under the measurement voltage;

[0009] Step 6, recording the rated voltage, thickness of the positioning gasket (5), creepage voltage, creepage path and other parameters of each measurement test;

[0010] The base (1) and two locking devices (2) are made of epoxy glass fiber laminate parts. The base (1) and the locking devices (2) are combined to form a U-shaped groove, simulating the stator core slot of the motor. The size of the U-shaped groove is: With reference to the current status of creepage distance research at home and abroad, and our factory's experience in creepage distance, the depth of the U-shaped groove of 50 mm can meet the measurement margin of the creepage distance, and the base (1) and the locking device (2) can also adjust their depths through the spacer strips;

[0011] After the base (1) and the locking device (2) are combined into a U-shaped groove, a copper bar (4) is placed at the bottom of the groove, and the size of the copper bar matches the size of the U-shaped groove. A positioning gasket (5) is placed above the copper bar, and the positioning gasket (5) itself is made of epoxy glass fiber laminate, and the specifications are divided into and Two specifications, with a practical quantity, meet the measurement requirements; when measuring, first use two specifications of positioning gaskets (5) to form a 20mm high combination according to the test voltage, and place the electrode locking device (3) above the positioning gasket (5); the electrode locking device (3) is made of a copper bar, and is divided into a locking device (3) and a positioning copper bar (6). The locking device (3) is connected to the high-voltage line of the high-voltage test transformer with a lead wire in the middle, and the positioning copper bar (6) is the same width as the positioning gasket (5), and the height is 10mm and 20mm, and is used to lock the positioning gasket (5); the high-voltage test transformer applies an industrial frequency voltage between the electrode locking device (3) and the copper bar (4), and starts to increase the voltage to reach the first stage maximum industrial frequency voltage 1.5U N During the test, when the applied voltage reaches 75% of the maximum test voltage, the voltage should be increased in stages at 5% of the maximum test voltage. The pressure increase process should be smooth. Once a serious discharge phenomenon occurs, the voltage should be immediately reduced and the inspection should be stopped. During the voltage increase process, when creepage occurs, the voltage at this time is recorded and the test is stopped. The voltage value at this time is the creepage voltage. After the discharge, the locking device (3) and the positioning copper bar (6) are removed, and the thickness of the positioning gasket (5) is measured. The thickness is the creepage distance under the measurement voltage. After the above preliminary test is completed, the creepage path on the surface of the positioning gasket (5) is checked. According to the distance of the creepage path, the above test is repeated. The thickness of the positioning gasket (5) is increased or decreased according to the creepage path to further verify the creepage distance under the measurement voltage.

[0012] After the base (1) and the locking device (2) are combined to form a U-shaped groove and used for a period of time, the polyimide film adhesive tape inside the U-shaped groove is re-attached, and the U-shaped groove can be reused; the number of positioning gaskets (5) is regularly replenished according to actual conditions based on usage, so as to be used for measuring creepage distance; the rated voltage, thickness of the positioning gasket (5), creepage voltage, creepage path and other parameters of each measurement test are recorded. After the creepage distance measurement test is completed, a comprehensive inspection is required to conduct the next verification test.

[0013] The working principle of the present invention is:

[0014] In order to prevent discharge or creepage between windings and other parts, there should be a certain creepage distance between them. The shortest distance between two adjacent conductors or one conductor and the winding insulation is the creepage distance. The present invention uses epoxy glass fiber laminate to make U-shaped slots to simulate the motor stator core slots. The size of the processed parts is: Referring to the current research status of creepage distance at home and abroad, and our factory's experience in creepage distance, the depth of the U-shaped groove of 50mm can meet the measurement margin of the creepage distance. Put a copper bar at the bottom of the groove, and the size of the copper bar matches the size of the U-shaped groove. Place a positioning gasket on the copper bar, and place an electrode locking device above the positioning gasket. Connect the lead in the middle of the locking device and connect it to the high-voltage line of the high-voltage test transformer. The high-voltage test transformer applies an industrial frequency voltage between the electrode locking device and the copper bar. During the boost process, when creepage occurs, record the voltage at this time and stop the test. The voltage value at this time is the creepage voltage. After discharge, remove the locking device and the positioning copper bar, and measure the thickness of the positioning gasket. The thickness is the creepage distance under the measured voltage.

[0015] The beneficial effects of the present invention are:

[0016] The present invention provides a tooling process for measuring creepage distance, wherein a U-shaped groove simulates a stator groove of a motor, and a polyimide film is attached to the inside of the U-shaped groove itself, so that the U-shaped groove can be reused. For different voltage levels, measurement is performed by adapting the thickness of a positioning gasket, and the creepage distance can be intuitively measured by the thickness of the positioning gasket, and the creepage trace of the positioning gasket itself is the creepage path. The present invention can accurately and conveniently measure the creepage distance under different voltage levels, so that the detection result is comparable and the accuracy is improved, which is of great significance for studying the creepage distance.

[0017] In order to prevent discharge or creepage between windings and other parts, there should be a certain creepage distance between them. The shortest distance between two adjacent conductors or one conductor and the winding insulation is the creepage distance. The present invention uses epoxy glass fiber laminate to make U-shaped slots to simulate the motor stator core slots. The size of the processed parts is: Referring to the current research status of creepage distance at home and abroad, and our factory's experience in creepage distance, the depth of the U-shaped groove of 50mm can meet the measurement margin of the creepage distance. Put a copper bar at the bottom of the groove, and the size of the copper bar matches the size of the U-shaped groove. Place a positioning gasket on the copper bar, and place an electrode locking device above the positioning gasket. Connect the lead in the middle of the locking device and connect it to the high-voltage line of the high-voltage test transformer. The high-voltage test transformer applies an industrial frequency voltage between the electrode locking device and the copper bar. During the boost process, when creepage occurs, record the voltage at this time and stop the test. The voltage value at this time is the creepage voltage. After discharge, remove the locking device and the positioning copper bar, and measure the thickness of the positioning gasket. The thickness is the creepage distance under the measured voltage.

[0018] The reason why the present invention chooses epoxy glass fiber laminate to make the base is that epoxy glass fiber laminate is a high-performance composite material, with glass fiber cloth as the base material and epoxy resin as the adhesive; it has excellent mechanical properties, and is not easy to deform or damage even when subjected to a large external force; good electrical insulation performance, suitable for occasions with high electrical insulation performance, can effectively prevent current leakage and electrical failure, and ensure electrical safety; excellent heat resistance, can maintain stable performance at high temperatures, high thermal deformation temperature, can be used for a long time at high temperatures; chemical corrosion resistance, can be used in harsh chemical environments, and is not easy to be corroded and damaged. And after the epoxy glass fiber laminate is used to make the U-shaped groove, a layer of YQ room temperature curing glue is brushed on the surface, and after moisture-proof treatment, a layer of polyimide film adhesive tape is attached to the surface. The polyimide film adhesive tape itself has excellent electrical insulation performance and thermal stability, and can withstand a breakdown voltage of >5kV, further enhancing the performance of the U-shaped groove, and after a certain number of uses, the polyimide film adhesive tape can be replaced again, ensuring a stable operating environment, reducing the interference of leakage current, and ensuring the accuracy of measurement data. Description of the drawings:

[0019] Figure 1 It is a schematic diagram of the present invention.

[0020] Figure 2 It is a cross-sectional view of the present invention. Specific implementation method:

[0021] like Figure 1 As shown in the figure, a method for measuring creepage distance using a positioning gasket, step 1, the base 1 and two locking devices 2 form a U-shaped groove, simulating the motor stator core slot, the U-shaped groove size is:

[0022] Step 2, put a copper bar 4 at the bottom of the U-shaped groove, the size of the copper bar is adapted to the size of the U-shaped groove, and a positioning gasket 5 is placed above the copper bar. When measuring, two specifications of positioning gaskets 5 are first combined into a 20mm high according to the test voltage, and an electrode locking device 3 is placed above the positioning gasket 5;

[0023] Step 3, such as Figure 2 As shown, the electrode locking device 3 is made of copper bars, which are divided into a locking device 3 and a positioning copper bar 6. The locking device 3 is connected to the high-voltage line of the high-voltage test transformer with a lead wire in the middle. The positioning copper bar 6 is consistent in width with the positioning gasket 5, and has a height of 10 mm and 20 mm, which is used to lock the positioning gasket 5. The high-voltage test transformer applies a power frequency voltage between the electrode locking device 3 and the copper bar 4. During the boosting process, when creepage occurs, the voltage at this time is recorded and the test is stopped. The voltage value at this time is the creepage voltage.

[0024] Step 4: After discharge, remove the locking device 3 and the positioning copper strip 6, and measure the thickness of the positioning gasket 5, which is the creepage distance under the measurement voltage;

[0025] Step 5, after the above preliminary test is completed, check the creepage path on the surface of the positioning gasket 5, and repeat the above test according to the distance of the creepage path. The thickness of the positioning gasket 5 is increased or decreased according to the creepage path to further verify the creepage distance under the measurement voltage;

[0026] Step 6, recording the parameters such as the rated voltage, the thickness of the positioning gasket 5, the creepage voltage and the creepage path of each measurement test;

[0027] The base 1 and two locking devices 2 are made of epoxy glass fiber laminate parts. The base 1 and the locking devices 2 are combined to form a U-shaped groove, simulating the motor stator core groove. The U-shaped groove size is: Referring to the current research status of creepage distance at home and abroad, and our factory's experience in creepage distance, the depth of the U-shaped groove of 50mm can meet the measurement margin of the creepage distance, and the base 1 and the locking device 2 can also adjust their depths through the gasket;

[0028] like Figure 2 As shown, after the base 1 and the locking device 2 of the present invention are combined into a U-shaped groove, a copper bar 4 is placed at the bottom of the groove, and the size of the copper bar is adapted to the size of the U-shaped groove. A positioning gasket 5 is placed above the copper bar, and the positioning gasket 5 itself is made of epoxy glass fiber laminate, and the specifications are divided into and Two specifications, with actual quantity, to meet the measurement needs. When measuring, first use two specifications of positioning gaskets 5 to combine into a 20mm high according to the test voltage, and place the electrode locking device 3 above the positioning gasket 5; the electrode locking device 3 is made of copper bars, which are divided into a locking device 3 and a positioning copper bar 6. The locking device 3 is connected to the high-voltage line of the high-voltage test transformer with a lead wire in the middle. The positioning copper bar 6 is the same width as the positioning gasket 5, with a height of 10mm and 20mm, and is used to lock the positioning gasket 5. The high-voltage test transformer applies an industrial frequency voltage between the electrode locking device 3 and the copper bar 4, and begins to boost the voltage to reach the highest industrial frequency voltage of 1.5U in the first stage. N During the process of voltage increase, when the applied voltage reaches 75% of the maximum test voltage, the voltage should be increased in sections at 5% of the maximum test voltage. The pressure increase process should be smooth. Once serious discharge occurs, the voltage should be immediately reduced and the inspection should be stopped. During the voltage increase process, when creepage occurs, record the voltage at this time and stop the test. The voltage value at this time is the creepage voltage. After discharge, remove the locking device 3 and the positioning copper strip 6, and measure the thickness of the positioning gasket 5. This thickness is the creepage distance under the measurement voltage.

[0029] After the above preliminary test is completed, the creepage path on the surface of the positioning gasket 5 is checked. According to the distance of the creepage path, the above test is repeated. The thickness of the positioning gasket 5 is increased or decreased according to the creepage path to further verify the creepage distance under the measurement voltage.

[0030] like Figure 1 As shown, after the base 1 and the locking device 2 are combined to form a U-shaped groove and used for a period of time, the polyimide film adhesive tape inside the U-shaped groove is re-attached, and then the U-shaped groove can be used again; the positioning gasket 5 is replenished regularly according to the actual situation according to the usage, so as to be used for measuring the creepage distance;

[0031] Record the rated voltage, thickness of positioning gasket 5, creepage voltage, creepage path and other parameters of each measurement test. After the creepage distance measurement test is completed, a comprehensive investigation is required to conduct the next verification test.

Claims

1. A method for measuring creepage distance using a positioning gasket, characterized in that: Step 1: The base (1) and two locking devices (2) form a U-shaped slot, simulating the motor stator core slot. The U-shaped slot dimensions are: Step 2, a copper bar (4) is placed at the bottom of the U-shaped groove, the size of the copper bar is adapted to the size of the U-shaped groove, and a positioning gasket (5) is placed above the copper bar. When measuring, two sizes of positioning gaskets (5) are first combined into a 20 mm high according to the test voltage, and an electrode locking device (3) is placed above the positioning gasket (5); Step 3, the electrode locking device (3) is made of a copper bar, and is divided into a locking device (3) and a positioning copper bar (6). The locking device (3) is connected to the high-voltage line of the high-voltage test transformer with a lead wire. The positioning copper bar (6) is consistent in width with the positioning gasket (5) and has a height of 10 mm and 20 mm, and is used to lock the positioning gasket (5). The high-voltage test transformer applies a power frequency voltage between the electrode locking device (3) and the copper bar (4). During the step-up process, when creepage occurs, the voltage at this time is recorded and the test is stopped. The voltage value at this time is the creepage voltage. Step 4, after discharging, remove the locking device (3) and the positioning copper strip (6), and measure the thickness of the positioning gasket (5), which is the creepage distance under the measurement voltage; Step 5, after the above preliminary test is completed, check the creepage path on the surface of the positioning gasket (5), and repeat the above test according to the distance of the creepage path. The thickness of the positioning gasket (5) is increased or decreased according to the creepage path to further verify the creepage distance under the measurement voltage; Step 6, recording the rated voltage, thickness of the positioning gasket (5), creepage voltage, creepage path and other parameters of each measurement test; The base (1) and two locking devices (2) are made of epoxy glass fiber laminate parts. The base (1) and the locking devices (2) are combined to form a U-shaped groove, simulating the stator core slot of the motor. The size of the U-shaped groove is 25.4×50×200 mm. Referring to the current research status of creepage distance at home and abroad and our factory's experience in creepage distance, the depth of the U-shaped groove of 50 mm can meet the measurement margin of the creepage distance, and the base (1) and the locking device (2) can also adjust their depths through gaskets.

2. The method for measuring creepage distance using a positioning gasket according to claim 1, characterized in that: After the base (1) and the locking device (2) are combined into a U-shaped groove, a copper bar (4) is placed at the bottom of the groove. The size of the copper bar matches the size of the U-shaped groove. A positioning gasket (5) is placed above the copper bar. The positioning gasket (5) is made of epoxy glass fiber laminate. The specifications are divided into 25.0 +-0 0.. 1 The two specifications are 1×1×200mm and 25.0×2×200mm, and the quantity is matched to meet the measurement requirements. When measuring, two specifications of positioning gaskets (5) are first combined into a 20mm high one according to the test voltage, and an electrode locking device (3) is placed above the positioning gasket (5); the electrode locking device (3) is made of a copper bar, and is divided into a locking device (3) and a positioning copper bar (6). A lead is connected in the middle of the locking device (3) and is connected to the high-voltage line of the high-voltage test transformer. The positioning copper bar (6) has a width consistent with that of the positioning gasket (5) and a height of 10mm and 20mm, and is used to lock the positioning gasket (5); the high-voltage test transformer applies an industrial frequency voltage between the electrode locking device (3) and the copper bar (4), and starts to increase the voltage to reach the first stage maximum industrial frequency voltage of 1.5U N During the process of increasing the voltage, when the applied voltage reaches 75% of the maximum test voltage, the voltage should be increased in stages at 5% of the maximum test voltage. The pressure increase process should be smooth. Once a serious discharge phenomenon occurs, the voltage should be immediately reduced and the inspection should be stopped. During the voltage increase process, when creepage occurs, the voltage at this time is recorded and the test is stopped. The voltage value at this time is the creepage voltage. After the discharge, the locking device (3) and the positioning copper bar (6) are removed, and the thickness of the positioning gasket (5) is measured. The thickness is the creepage distance under the measurement voltage. After the above preliminary test is completed, the creepage path on the surface of the positioning gasket (5) is checked. According to the distance of the creepage path, the above test is repeated. The thickness of the positioning gasket (5) is increased or decreased according to the creepage path to further verify the creepage distance under the measurement voltage.

3. The method for measuring creepage distance using a positioning gasket according to claim 1, characterized in that: After the base (1) and the locking device (2) are combined to form a U-shaped groove and used for a period of time, the polyimide film adhesive tape inside the U-shaped groove is re-attached, and the U-shaped groove can be reused; the number of positioning gaskets (5) is regularly replenished according to actual conditions based on usage, so as to be used for measuring creepage distance; the rated voltage, thickness of the positioning gasket (5), creepage voltage, creepage path and other parameters of each measurement test are recorded. After the creepage distance measurement test is completed, a comprehensive inspection is required to conduct the next verification test.

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