Method and device for detecting interlayer insulation performance of ultra-thin silicon steel winding iron core

Abstract

The invention relates to a method and a device for detecting the interlayer insulation performance of an ultrathin silicon steel winding iron core. Wherein the method simulates a high-voltage pulse; impacting an insulating layer of a to-be-detected iron core by using high-voltage pulse, wherein the to-be-detected iron core is acquired in advance; obtaining the current first wave crest current and wave trough current of the to-be-measured iron core, and calculating a corresponding positive and negative current ratio; obtaining positive and negative current ratios for multiple times; and when the change of the positive and negative current ratio of the last calculation relative to the first calculation meets a preset condition, determining that the interlayer insulation of the to-be-detected iron core is damaged. Compared with the prior art, the method has the advantages that the iron core with the damaged interlayer insulation can be quickly screened out, and the risk of large loss caused by insulation damage after the electromagnetic element is packaged is avoided in advance.

Description

Technical Field

[0001] The invention relates to the technical field of insulation detection, and in particular to a method and a device for detecting the insulation performance between layers of an ultra-thin silicon steel wound iron core. Background Art

[0002] Silicon steel is an extremely low silicon-iron soft magnetic alloy with a carbon content of 0.5% to 4.5%. It has the characteristics of high magnetic permeability, low coercive force, and large resistivity, so the hysteresis loss and eddy current loss are small. It is mainly used as a magnetic material in motors, transformers, reactors, and electrical instruments. The performance requirements of the cold-rolled silicon steel sheets used in the wound core include low iron loss, high magnetic induction intensity, smooth surface, etc. These characteristics help to improve the efficiency and performance of products such as transformers and reactors. When the electromagnetic device is working, an induced current will be generated, circulating in a plane perpendicular to the direction of the magnetic flux. These induced currents will form eddy currents in the core, resulting in energy loss. In practical applications, cold-rolled silicon steel sheets are usually coated with an insulating coating, and the core is composed of thin steel sheets coated with an insulating coating wound or stacked, and then through processes such as vacuum varnishing, the above method is used to reduce the flow path of the eddy current in the cross section of the core, increase the resistance on the path, and thus reduce the loss of eddy current.

[0003] The insulation between adjacent layers of silicon steel sheets in the ultra-thin silicon steel wound core is interlayer insulation. During the processing of the core, the interlayer insulation may have defects such as unevenness and bubbles, or the coating may be damaged due to the influence of humidity, high temperature, and chemical substances in the storage environment, which may damage the interlayer insulation, resulting in contact between adjacent silicon steel sheets and forming a low-impedance channel, so that the current forms a loop on the path, resulting in obvious eddy current effect and increased core loss. Therefore, it is very necessary to detect the damage of the interlayer insulation of the core in time to avoid large core losses in advance.

[0004] The common methods for testing the performance of interlayer insulation of silicon steel sheet cores are: 1. Indirect detection method of infrared thermal imaging, using an infrared thermal imager to detect the heat distribution of the core under operation. Abnormal hot spots may indicate insulation problems. Although this method can intuitively display the parts with poor insulation, it is greatly affected by the environment and equipment accuracy. It can only detect the core that is in operation and not encapsulated by the shell, and is not suitable for the detection of the core in non-operating state. 2. Insulation resistance test method. The insulation condition is judged by measuring the insulation resistance value of the lamination with a megohmmeter (high resistance meter). Because the test voltage is very low, this method cannot fully reflect the actual situation of the interlayer insulation of the core silicon steel sheet under actual working conditions, and is not sensitive to the detection of minor defects or local poor insulation.

[0005] Therefore, how to improve the accuracy of insulation detection and apply it to the core in a non-operating state to effectively avoid large core losses in advance has become a problem that needs to be solved in this field. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a method and device for detecting the interlayer insulation performance of ultra-thin silicon steel wound core. The method is suitable for insulation detection of the core in a non-operating state, and can improve the accuracy of insulation detection, thereby avoiding large core losses in advance.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] According to a first aspect of the present invention, there is provided a method for detecting the interlayer insulation performance of an ultra-thin silicon steel wound core, the method comprising the following steps: S1, simulating a high-voltage pulse; S2, using the high-voltage pulse to impact the insulation layer of a core to be tested, wherein the core to be tested is obtained in advance; S3, obtaining the first current peak current and valley current of the core to be tested, and calculating the corresponding positive and negative current ratio; S4, repeating S1 to S3, and obtaining a plurality of positive and negative current ratios; S5, when a comparison result of the positive and negative current ratios calculated for the last time and for the first time meets a preset condition, determining that the interlayer insulation of the core to be tested is damaged.

[0009] As a preferred technical solution, the preset condition includes that the positive and negative current ratio calculated for the last time is lower than 95% of the positive and negative current ratio calculated for the first time.

[0010] According to a second aspect of the present invention, there is provided a device for detecting the insulation performance between layers of an ultra-thin silicon steel wound core, the device being used to implement the method described, the device comprising an impact system console, a high-voltage impact capacitor, a current induction loop, a capacitive voltage divider, an insulating platform and a test coil; a pre-acquired core to be tested is installed in the test coil, the test coil is placed on the insulating platform, one end of the insulating platform is connected to a high voltage, and the other end is grounded, the test coil is connected to the high-voltage impact capacitor, the current induction loop is sleeved on the connecting line between the two, the interface end of the current induction loop is connected to the impact system console, the capacitive voltage divider is connected between the test coil and the impact system console, and the high-voltage impact capacitor is connected to the impact system console.

[0011] As a preferred technical solution, the impact system console also includes an oscilloscope.

[0012] As a preferred technical solution, a groove is provided inside the insulating platform, and a flip plate, a first supporting element and a telescopic block are arranged in the groove from top to bottom in sequence, and the flip plate and the telescopic block are connected through the first supporting element.

[0013] As a preferred technical solution, a second supporting element is provided on the side surface of the flip plate, the flip plate is connected to the inner wall of the insulating platform through the second supporting element, the upper surface of the flip plate is fixedly connected to the first handle, and the outer surface of the insulating platform is fixedly connected to the second handle.

[0014] As a preferred technical solution, the insulating platform further includes a plug-in block and an extension ring, the plug-in block is plugged into the flip plate, and the extension ring is fixedly connected to the inner wall of the insulating platform.

[0015] As a preferred technical solution, both ends of the plug-in block are fixedly connected to the vibration plate, and the bottom is fixedly connected to the extension block.

[0016] As a preferred technical solution, the bottom of the extension ring is connected to a fixed elastic element.

[0017] As a preferred technical solution, the diameter of the vibration plate is larger than the diameter of the plug-in block.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The detection method proposed in the present invention can quickly judge the interlayer insulation performance of the iron core to be tested by applying several high-voltage shocks similar to the actual working conditions to the iron core to be tested, and then judging the quality of the interlayer insulation performance of the iron core to be tested according to the positive and negative current ratios obtained from the first and last measurements. This method is suitable for insulation detection of the iron core in a non-operating state. On the one hand, applying high-voltage pulses similar to the actual working conditions helps to fully reflect the real situation of the interlayer insulation of the iron core silicon steel sheet under the actual working conditions, improve the sensitivity of detecting small defects or local poor insulation, and thus improve the accuracy of insulation detection. On the other hand, it can quickly screen out the iron core with damaged interlayer insulation, and avoid the risk of excessive loss caused by insulation damage after the electromagnetic components are encapsulated in advance;

[0020] 2. The detection method proposed by the present invention can be realized by using a detection device composed of an impact system console, a high-voltage impact capacitor, a current induction loop, a capacitive voltage divider, an insulating platform and a test coil. It is simple, fast, easy to operate, and suitable for batch detection of iron cores.

[0021] 3. In the detection device proposed in the present invention, a slot is provided inside the insulating platform, and a flip plate, a first supporting element and a telescopic block are arranged in the slot from top to bottom in sequence. During detection, the iron core to be tested is placed on the surface of the flip plate for testing. When the flip plate is not in use, the telescopic block is pushed down, and the first supporting element is lowered along with the telescopic block, so that the first supporting element is no longer supported on the bottom of the flip plate. At this time, the flip plate is flipped along the second supporting element, which can effectively prevent dust and garbage from accumulating on the surface of the flip plate and extend the service life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic flow chart of a method for providing embodiment 1 of the present invention;

[0023] Figure 2 A schematic diagram of the structure of a device is provided for Embodiment 2 of the present invention;

[0024] Figure 3 This is a schematic diagram of the insulating platform structure of the device in Example 2 of the present invention;

[0025] Figure 4 This is a schematic diagram of the cross-sectional structure of the insulating platform of the device in Example 2 of the present invention;

[0026] Figure 5 This is a schematic structural diagram of the insulating platform cross section of the device in Example 2 of the present invention from another viewing angle;

[0027] Wherein: 1. impact system control console; 2. high voltage impact capacitor; 3. current induction loop; 4. capacitive voltage divider; 5. insulating platform; 6. test coil; 7. iron core to be tested; 501. slot; 502. flip plate; 503. first supporting element; 504. telescopic block; 505. second supporting element; 506. first handle; 507. second handle; 508. plug-in block; 509. extension ring; 5081. vibration plate; 5082. extension block; 510. spring; 5041. base. DETAILED DESCRIPTION

[0028] The present invention provides a method and device for detecting the interlayer insulation performance of an ultra-thin silicon steel wound core. The method comprises: step S1, simulating a high voltage pulse; step S2, using a high voltage pulse to impact the insulation layer of the core to be tested, the core to be tested is obtained in advance; step S3, obtaining the first peak current and valley current of the core to be tested, and calculating the corresponding positive and negative current ratio; step S4, repeating steps S1 to S3, obtaining multiple positive and negative current ratios; step S5, when the change of the positive and negative current ratio calculated in the last calculation relative to the first calculation meets the preset condition, it is determined that the interlayer insulation of the core to be tested is damaged. The device is used to implement each step of the above-mentioned method, and the device includes an impact system console, a high-voltage impact capacitor, a current induction loop, a capacitive voltage divider, an insulating platform and a test coil; the pre-obtained iron core to be tested is installed in the test coil, the test coil is placed on the insulating platform, one end of the insulating platform is connected to a high voltage, and the other end is grounded, the test coil is connected to the high-voltage impact capacitor, a current induction loop is set on the connecting line between the two, the interface end of the current induction loop is connected to the impact system console, the capacitive voltage divider is connected between the test coil and the impact system console, and the high-voltage impact capacitor is connected to the impact system console.

[0029] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following embodiments.

[0030] Example 1

[0031] like Figure 1 As shown, this embodiment provides a method for detecting the insulation performance between layers of an ultra-thin silicon steel wound core. The specific process of implementing the method includes:

[0032] A test circuit is built using the existing high-voltage pulse simulation system, high-voltage impact capacitor and test coil. The ultra-thin silicon steel wound core to be tested is installed inside the test coil. The high-voltage pulse simulation system, high-voltage impact capacitor and test coil are connected in sequence, and the other end of the test coil is grounded.

[0033] Based on the established test circuit, the high-voltage pulse simulation system is used to simulate high-voltage pulses to charge the high-voltage impact capacitor; when the voltage in the circuit gradually increases to the preset threshold, the switch is automatically triggered, and the high-voltage impact capacitor will release a high-voltage pulse and apply it to the test coil. Under the action of the high-voltage pulse, the insulation layer in the iron core to be tested will be impacted by the impact voltage. Through real-time monitoring and recording, the first peak current and valley current of the iron core to be tested are collected, and the corresponding positive and negative current ratio is calculated.

[0034] Repeat the above-mentioned test process of simulating high-voltage pulses - impacting the insulation of the iron core to be tested - calculating the positive and negative current ratio, and conduct at least two impact tests. Compare the positive and negative current ratios of the first and last experiments. When the positive and negative current ratio calculated for the last time is lower than 95% of the positive and negative current ratio calculated for the first time, it is determined that the interlayer insulation of the iron core is damaged.

[0035] Example 2

[0036] like Figure 2As shown, this embodiment provides a detection device for the interlayer insulation performance of ultra-thin silicon steel wound core, which can implement the method described in Example 1. The device includes an impact system console 1, a high-voltage impact capacitor 2, a current induction loop 3, a capacitive voltage divider 4, an insulating platform 5 and a test coil 6; the pre-obtained test core 7 is installed in the test coil 6, and the test coil 6 is placed on the insulating platform 5, one end of the insulating platform 5 is connected to a high voltage, and the other end is connected to a ground wire; the test coil 6 is connected to the high-voltage impact capacitor 2, and a current induction loop 3 is set on the connecting wire between the two, and the interface end of the current induction loop 3 is connected to the impact system console 1, one end of the capacitive voltage divider 4 is connected to the test coil 6, and the other end is connected to the impact system console 1, and the high-voltage impact capacitor 2 is connected to the impact system console 1, and the impact system console 1 also includes an oscilloscope. In the figure, the impact system console 1, the high-voltage impact capacitor 2, and the test coil 6 connected in sequence together constitute a test circuit.

[0037] Based on the established test circuit and test environment, the specific process of using the detection device to test the interlayer insulation performance of ultra-thin silicon steel wound core is as follows:

[0038] (1) Place the test coil 6 on the insulating platform 5, connect one end to the high voltage and the other end to the ground wire, install the iron core 7 to be tested on the test coil 6, and after confirming that the wiring is good, set up a safety isolation zone, and keep all personnel away from the isolation area of ​​the test system;

[0039] (2) Control the impact system console 1 to set parameters to simulate high-voltage pulses. After confirmation, the impact system console 1 will charge the high-voltage impact capacitor 2 and store energy in the high-voltage impact capacitor 2. After the voltage in the circuit gradually increases to the set parameters, the switch will be automatically triggered, and the high-voltage impact capacitor 2 will release a high-voltage pulse and apply it to the test coil 6. Under the action of the high-voltage pulse, the insulation layer in the iron core 7 to be tested will be impacted by the impact voltage;

[0040] (3) During the test, the capacitive voltage divider 4 and the current sensing loop 3 will monitor the voltage and current parameters on the iron core 7 to be tested and transmit them to the oscilloscope;

[0041] (4) The oscilloscope collects the first peak current and valley current of the iron core 7 to be tested, and calculates the positive and negative current ratio;

[0042] (5) Repeat (2) to (4) and conduct 2 to 5 impact tests. Calculate the change in the ratio of the positive and negative currents between the first and last tests. When the last calculated result is lower than 95% of the first calculated result, it can be determined that the interlayer insulation of the iron core 7 to be tested is damaged.

[0043] like Figure 3 to Figure 5As shown, the insulating platform 5 used in the device in this embodiment has a slot 501 formed inside, and a flip plate 502, a first supporting element 503 and a telescopic block 504 are arranged in the slot 501 from top to bottom, and the flip plate 502 and the telescopic block 504 are connected through the first supporting element 503.

[0044] A second supporting element 505 is provided on the side surface of the flip plate 502, and the flip plate 502 is connected to the inner wall of the insulating platform 5 through the second supporting element 505. The upper surface of the flip plate 502 is fixedly connected to the first handle 506, and the outer surface of the insulating platform 5 is fixedly connected to the second handle 507. The second supporting element 505 adopts a rotating shaft, and the rotating shaft is provided in two groups, and the flip plate 502 can rotate along the rotating shaft.

[0045] The insulating platform 5 also includes a plug-in block 508 and an extension ring 509. The plug-in block 508 is plugged into the flip plate 502, and the extension ring 509 is fixedly connected to the inner wall of the insulating platform 5. The two ends of the plug-in block 508 are fixedly connected to the vibration plate 5081, and the bottom is fixedly connected to the extension block 5082. The diameter of the vibration plate 5081 is larger than the diameter of the plug-in block 508. The bottom of the extension ring 509 is connected to a fixed elastic element. The elastic element is a spring 510, and the spring 510 has a thrust on the telescopic block 504.

[0046] One end of the spring 510 is connected to the lower surface of the extension ring 509, and the other end is connected to the upper surface of the telescopic block 504. The telescopic block 504 is located inside the slot 501 and can move in the slot 501. A base 5041 is fixed to the bottom of the telescopic block 504. The upper surface of the telescopic block 504 is fixedly connected to the first supporting element 503, and the first supporting element 503 is a supporting rod. The supporting rod is provided in multiple groups, and the top of the supporting rod is supported on the bottom of the flip plate 502.

[0047] When the above device is used for testing, the iron core 7 to be tested is placed on the flip plate 502 for testing and recording. When the flip plate 502 is not in use, a large amount of dust and garbage will accumulate on its surface. The insulating platform 5 is lifted up by the second handle 507, so that the telescopic block 504 is lowered under the push of the spring 510, the base 5041 is lowered with the telescopic block 504, and the first supporting element 503 is lowered with the telescopic block 504. The first supporting element 503 is no longer supported on the bottom of the flip plate 502. The flip plate 502 can be flipped along the rotating shaft by the first handle 506, which plays a role in preventing dust and garbage from accumulating on the surface of the flip plate 502. The plug-in block 508 is driven to move by the extension block 5082. The plug-in block 508 can shake off the dust on the surface of the flip plate 502 during the movement, and the vibration plate 5081 plays a limiting role.

[0048] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for detecting the insulation performance between layers of an ultra-thin silicon steel wound core, characterized in that: The method The following steps are involved: S1, simulated high voltage pulse; S2, using the high voltage pulse to impact the insulation layer of the iron core to be tested, where the iron core to be tested is obtained in advance; S3, obtaining the first peak current and valley current of the iron core to be tested, and calculating the corresponding positive and negative current ratio; S4, repeat S1 to S3 to obtain multiple positive and negative current ratios; S5, when the comparison result of the positive and negative current ratios calculated for the last time and for the first time meets a preset condition, it is determined that the interlayer insulation of the iron core to be tested is damaged.

2. The method for detecting the interlayer insulation performance of the ultra-thin silicon steel wound core according to claim 1, characterized in that: The preset condition includes that the forward and reverse current ratio calculated for the last time is lower than 95% of the forward and reverse current ratio calculated for the first time.

3. A device for detecting the insulation performance between layers of an ultra-thin silicon steel wound core, characterized in that: The device is used to implement the method according to any one of claims 1-2, and the device comprises an impact system console, a high-voltage impact capacitor, a current induction loop, a capacitive voltage divider, an insulating platform and a test coil; The pre-obtained iron core to be tested is installed in the test coil, and the test coil is placed on the insulating platform. One end of the insulating platform is connected to a high voltage, and the other end is grounded. The test coil is connected to the high-voltage impact capacitor, and the current induction loop is set on the connecting line between the two. The interface end of the current induction loop is connected to the impact system console, the capacitive voltage divider is connected between the test coil and the impact system console, and the high-voltage impact capacitor is connected to the impact system console.

4. The device for detecting the insulation performance between layers of the ultra-thin silicon steel wound core according to claim 3 is characterized in that: The impact system console also includes an oscilloscope.

5. The device for detecting the insulation performance between layers of the ultra-thin silicon steel wound core according to claim 3, characterized in that: A slot is formed inside the insulating platform, and a flip plate, a first supporting element and a telescopic block are arranged in the slot in sequence from top to bottom. The flip plate and the telescopic block are connected through the first supporting element.

6. The device for detecting the insulation performance between layers of the ultra-thin silicon steel wound core according to claim 5, characterized in that: A second supporting element is arranged on the side surface of the flip plate, the flip plate is connected to the inner wall of the insulating platform through the second supporting element, the upper surface of the flip plate is fixedly connected to the first handle, and the outer surface of the insulating platform is fixedly connected to the second handle.

7. The device for detecting the insulation performance between layers of the ultra-thin silicon steel wound core according to claim 5, characterized in that: The insulating platform also includes a plug-in block and an extension ring, wherein the plug-in block is plugged into the flip plate, and the extension ring is fixedly connected to the inner wall of the insulating platform.

8. The device for detecting the insulation performance between layers of the ultra-thin silicon steel wound core according to claim 7, characterized in that: The two ends of the plug-in block are fixedly connected to the vibration plate, and the bottom is fixedly connected to the extension block.

9. The device for detecting the insulation performance between layers of the ultra-thin silicon steel wound core according to claim 7, characterized in that: The bottom of the extension ring is connected to a fixed elastic element.

10. The device for detecting the insulation performance between layers of the ultra-thin silicon steel wound core according to claim 8, characterized in that: The diameter of the vibration plate is greater than the diameter of the plug-in block.

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