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Application of the first phase of insulation material communication in the insulation of domestic AC motor insulation Wei Guoqing Wang Fangwen Xiangtan Motor Group Co., Ltd. Mica tape P insulation application in AC high voltage motor is still in the beginning and small batch trial stage.
The prototype of the motor was successfully produced by the Swiss Esola company with less rubber mica tape and anti-corona material.
A comparative test was carried out on the Esola Less Mica Tape and the Domestic Less Mica Tape, which pointed out the direction for improving the domestic materials.
Descriptor less rubber mica with basin gas PI insulation electrical aging life breakdown voltage preface At present, China's AC high voltage motor main insulation has multiple rubber powder mica with mold hydraulic insulation rubber powder mica tape edge and less rubber powder mica with PI insulation, etc. system.
From the perspective of comprehensive performance and long-term development, the insulation of less rubber mica tape is undoubtedly the development direction of China's high-voltage motor insulation manufacturing technology.
Compared with the first two insulation systems, the mica content in the less rubber mica tape insulation is significantly improved, there is no air gap in the insulation, and the integrity is good, which is beneficial to improve the electrical performance of the insulation and the corona resistance and electric life, thereby improving the motor. The technical specifications of the operating life and operational reliability, while greatly simplifying the coil manufacturing process, not only shorten the production cycle, reduce manufacturing costs, but also help improve the insulation quality of the coil.
Since the introduction of foreign high-voltage motor manufacturing technology and corresponding equipment since the beginning of the year, China has carried out a lot of research work on material insulation structure and technology for IP insulation system of less rubber mica tape. However, due to its technical difficulty, especially less glue The manufacture of mica tapes involves a wide range of applications, so the progress is not fast. So far, there are only a few manufacturers in China that promote the application.
Since the company's first trial of the first batch of low-mica mica belt edge motor, the factory has gradually invested a small amount and mass production after some necessary technical transformation. In recent years, hundreds of new insulated series AC high-voltage motors have been put into industrial operation.
Through the user tracking investigation of the first batch of motor trials, the motor insulation operation is reliable.
However, the application of new insulation on the motor is still in its infancy in China.
In the process of developing and promoting the insulation of the less rubber mica tape, we deeply understand the importance of the quality of the supporting materials.
Several key materials, such as impregnating mica tape and anti-corona material, have been developed in the country for many years, and gradually developed in the process of improving the application. Now it can basically meet the requirements of application process and performance, but from In terms of the overall level, there is still a certain gap compared with the advanced level of foreign countries.
Swiss Essola is an internationally renowned multinational group of companies producing insulating materials and magnet wires. It produces a variety of non-gel mica tape insulation materials including mica tape impregnating resin and anti-corona materials. I have been in the early 1980s. When visiting the company, their materials such as less rubber mica tape have been widely used in order to open up the Chinese market and promote the accelerated development of China's IP insulation technology. Isola and our company have fully negotiated and tested the preparation work, decided by Isola The company provides less rubber mica tape and anti-corona material, and our company prototypes the AC motor prototype.
In the trial production process, Esola technical experts visited the on-site technical guidance. Thanks to the joint efforts of both parties, the prototype motor was successfully completed in the end of the year.
The main materials and performance test less rubber mica with the low-mica mica tape provided by Esola, the model is a large scale flake mica tape with single-sided reinforcement of lanthanized glass cloth, and the first phase of communication with resin-free insulating materials without curing agent. Combined, the heat resistance level can reach the level.
This mica tape can be compatible with any impregnating resin known as epoxy or polyester.
In order to reduce costs and facilitate sales in China, the materials used in these belts are all made in China, and the belts are made in Switzerland.
Before the trial production of the motor, in order to compare with the domestically produced less rubber mica tape, Esola Company conducted performance test and test on the domestically produced tape provided by our company. The test results are described later. The table lists the Esso. Pull the technical indicators of the belt and the test results of the domestic belt.
It can be seen from the table that other properties of domestic tapes are OK, only the air permeability is obviously poor, and the softness stiffness does not meet the requirements of the Esola index.
Table part of domestic small rubber mica tape performance and indicators comparison index name unit isola tape index value domestic test value bandwidth thickness unit area quality stone mica quantitative glass cloth quantitative adhesive content stiffness town tensile strength permeability breakdown voltage even The mica tape provided by the mica belt with Isoola is a medium-sized rubber mica tape with a double-sided reinforcement of glass cloth and polyester vinegar, because it is double-sided reinforcing and has a slightly higher glue content, so the tape Good mechanical strength and easy to dress.
The main technical indicators table connection with mica tape performance main technical indicators see table low resistance, with performance indicators name unit index value thickness unit area area quality child mica quantitative soil Bray cloth quantitative resin content non-woven fabrics Tensile strength stiffness core permeability index indicator unit unit index value thickness unit area quality non-woven fabric fixed children's conductive paint quantitative tensile strength elongation surface resistivity high resistance anti-halo performance anti-corona material The low-resistance anti-corona plate is made of a conductive paint impregnated with a carbon-containing particle by a polyester vinegar nonwoven fabric.
The tape has solvent resistance and good elasticity, ensuring tight dressing and uniform resistance across the entire dressing surface.
Index of the tape, the index of the index, the thickness of the unit, the quality of the material, the tensile strength, the elongation, the shrinkage, the Essola, the high-resistance, the anti-corona, the grade is made of silicon carbide coated on the polyester fabric, and the annual insulation material. The first phase of the communication is fully cured. The tape can be used for multi-molding or non-molding. It has non-linear current-voltage characteristics. Its main technical indicators are low resistance band or high resistance band. According to the company, the conductive particles on the tape are in use. It will not fall and will not contaminate the impregnating resin at the time.
Impregnating resin Esola uses impregnating resin grades as a solventless unsaturated polyacetimimine resin.
It is used in the high-voltage maximum motor and traction motor to form the exclusive insulation system of Isola. It has good mechanical and dielectric properties and the heat resistance level is up to grade.
The resin has the characteristics of low viscosity, good storage stability, low curing temperature, short time and low cost.
When the motor was trial-produced, it was difficult to replace the resin in our company, so the domestic resin was still used, and no resin was used.
Electrical performance test In order to test the electrical properties of the coil insulation after the comparison of the Essola tape and the domestic tape with the domestic resin, our company provides several specifications of the white coil wire number n åŒ coil total length straight long core long span The cross-sectional dimension of the straight part after insulation from the height before the insulation is included. The cross-sectional dimension of the straight part including the anti-halation layer is coated with the Essola tape and the domestic tape.
The outer bread is made of Essola low resistance tape with high resistance tape and shrink tape, and then impregnated with domestic resin with simulated groove. After curing, the simulated groove is removed to test the electrical properties of the coil insulation.
All of the above work was done in the laboratory of the Isola company in Switzerland.
Test the dielectric loss of each coil at different test voltages at room temperature and high temperature, and make a dielectric loss voltage curve. The graph shows several representative curves. It can be seen that the loss of dielectric loss between the two tapes is not much different at room temperature. Essola tape is obviously superior to domestic tape at high temperature. .
The relationship between the dielectric loss and the voltage of the coil insulation at different temperatures at different temperatures. The breakdown voltage of the two coils wrapped with the Esola belt is tested. For the motor prototype motor type o wire number åŒ single double row coil total length straight long core long span height insulation front part of the line section size insulation after the cross section size includes anti-half layer coil manufacturing and less tape coil The manufacturing process is the same.
The tape is wrapped with a common tape machine. The tensile strength and softness of the tape can meet the requirements of the bag. The band is basically not lost when the bag is wrapped. The powder is slightly multi-level and high-resistance. The halo band is hand-wrapped to meet the dressing. Process requirements.
The coil inlay assembly and the finished product test were carried out according to the normal procedure, and all the withstand voltage tests were passed.
The mica tape used for the connection of the insulation materials in the first year of the package can better meet the requirements of the dressing.
The thermal insulation resistance of the whole stator after prebaking and the thermal insulation resistance after baking and curing. In order to test the electrical properties of the insulation, a test wire rod was prepared simultaneously during the trial production of the motor.
The size of the wire holding aluminum row is the number of layers of the tape and the thickness of the insulation are the same as the actual motor coil. The thickness of the single-sided insulation is different from that of the low-resistance tape and the high-resistance tape, and then the simulated iron core groove is used along with the motor product road. IP and baking cure, finally remove the analog tank, and test the electrical properties of the insulation with aluminum foil electrodes.
The surface resistivity of the rear groove of the bar is less than n orders of magnitude, the bar stun voltage is higher than the room temperature and the dielectric loss and the instantaneous power frequency breakdown voltage test results. See the electrical performance of the wire bar. The room temperature breakdown voltage bar type Ancient anvil crawling electricity climbing China has not yet formulated the technical requirements or quality classification rules for high-voltage motor and less rubber mica with IP insulated coils, but refer to the existing industry standards for molded insulation or medium tape edge coils, listed in the table. Several test results of dielectric loss have reached the excellent product standard in both normal and thermal states. However, the instantaneous power frequency breakdown voltage is only close to the qualified standard.
In fact, when the motor was trial-produced, our company's equipment needed to be repaired and the vacuum could not be less than the requirement. If the vacuum of the equipment can be higher, the electrical performance of the insulation is expected to be better.
Conclusion Esola's low-mica mica tape and anti-corona material have been applied in our company's AC high-voltage motor, which proves that it can meet the requirements of manufacturing process and insulation performance. They are insulated with domestic resin impregnation system, and the electrical performance is instantaneous. The power frequency breakdown voltage meets the excellent quality standards of the domestic industry.
In view of the performance of all aspects, the Esola material has a higher level than the domestically produced materials.
After the comparison test of Isola and the actual application of our company, there is still a certain gap between the domestically produced less mica tape and the Esola material, such as the air permeability of the tape, the thermal dielectric loss of the post insulation, and hope that there is less tape in the country. And its raw material manufacturers continue to work hard to improve and improve, as soon as possible to catch up with the advanced level of foreign materials.
For the instantaneous power frequency breakdown voltage index of coil insulation, China's industry standards generally require the above, and in this trial production and test, even if the internationally advanced Esola mica tape is used, it is prepared by our company and Yisola company respectively. Insulated thickness coils or bars have measured levels of breakdown voltage that are not exceeded.
According to the author's communication with foreign technical experts for many years, they all pay less attention to the instantaneous breakdown value. They think that the breakdown voltage value does not represent the long-term life, and the standard, the coil breakdown voltage value only requires ten times than the industry standard in China. It is low.
For the insulation of high-voltage motors, the electrical aging life is generally valued abroad. From the past few years, our company and the brothers' manufacturers have tested the electrical aging life evaluation tests for the insulation thickness of the coils, and their breakdown voltages are reliable. Not all of the requirements are met. Therefore, we believe that the instantaneous breakdown voltage value of high voltage coils in China is debatable.
China's current high-voltage coil insulation thickness is quite different from the foreign advanced level. If this problem is not solved, it will definitely affect the improvement of China's high-voltage motor design and manufacturing level.