60 results about "Electric strength" patented technology

The invention belongs to the technical field of production of insulating products, and discloses a production method of an insulating paperboard, which comprises the following steps: grinding pulp through a DD720 double-disc refiner, respectively adding a modified additive PDMS (Polydimethylsiloxane) emulsion and a phenyl silicone emulsion into the pulp, mixing with a cross-linking agent, adding a cross-linking agent, and uniformly stirring to obtain the insulating paperboard. Or adding a modified additive PDMS emulsion and a phenyl silicone emulsion into the slurry at the same time, and then mixing with a cross-linking agent; mechanically stirring the mixed pulp by a propeller, standing, and carrying out drifting purification, papermaking by a paper machine, multi-section hot pressing and cutting and shaping to obtain a finished paperboard. According to the insulating paperboard prepared by the production method, the electrical strength index value of an existing product in air can be improved by 30%-50%, so that the influence of aging damage to an insulating material caused by high-voltage, high-temperature and complex electromagnetic environments in the operation process of a transformer is reduced, the service life of the transformer is prolonged, and the safe operation performance of the transformer is improved.

The invention discloses polyimide with high surface electric strength based on surface natural microporous structure regulation and a preparation method and application thereof, and belongs to the technical field of high-voltage insulating materials. Dried diamine is dissolved in a solvent A, dianhydride is added, and after uniform stirring, a polyamide acid solution is obtained; adding a pore-forming agent, and stirring at a high speed until the mixture is uniformly dispersed to obtain a mixed viscous solution C; after coating, drying, imidization high-temperature heating and natural cooling, immersing into the liquid B to extract the pore-forming agent, and drying to obtain the high-surface electric strength polyimide based on surface natural microporous structure regulation and control. The surface of the polyimide has a natural porous structure, the surface is a surface along an electric field and a through hole structure densely distributed along the surface of the electric field, and electrons are easy to fall into the through hole structure and are difficult to return to the surface in a jump multiplication process during flashover, so that a secondary electron multiplication process is inhibited, the probability of forming secondary electron collapse is reduced, and the flashover effect is improved. Therefore, the along-surface electric strength is improved.

The present invention relates to a two-liquid high-voltage epoxy insulating casting resin and a preparation method, and belongs to the field of insulating epoxy casting resin. The two-liquid high-voltage epoxy insulating casting resin is composed of component A and component B, wherein component A includes: 80-90 parts by weight of epoxy resin, 1-5 parts by weight of polyether polyol, 5-15 parts by weight of toughening agent, 0.1-0.5 parts by weight of defoaming agent and 0.1-0.5 parts by weight of dispersant; component B includes: 80-93 parts by weight of anhydride curing agent, 5-15 parts by weight of toughening agent and 0.2-1.0 parts by weight of accelerator. The two-liquid high-voltage epoxy insulating casting resin has excellent high and low temperature impact resistance, electrical strength and mechanical properties, is easy to operate, and has a rapid increase in glass transition temperature, which can effectively improve production efficiency and is suitable for the equipment and manufacture of high-voltage insulating devices.

The invention relates to the technical field of power system transformers, and discloses a converter transformer oil paper insulation electrical strength prediction method, which comprises the following steps: S01, setting the temperature of a converter transformer oil paper insulation sample, S02, applying voltage to the converter transformer oil paper insulation sample to generate breakdown, S03, collecting breakdown strength data, and S04, determining the electrical strength of the converter transformer oil paper insulation sample. S04, analyzing breakdown strength data, S05, fitting breakdown data according to a quadratic nonlinear regression equation, and S06, predicting the electrical strength of the oil paper insulation of the converter transformer, namely predicting the breakdown strength of the oil paper insulation material under different temperature and harmonic frequency conditions, and determining the electrical strength of the oil paper insulation according to the influence of the temperature and the frequency on the electrical strength of the oil paper insulation. The method can more comprehensively reflect the insulation state under the actual operation condition, and provides a theoretical basis for the evaluation of the insulation performance of the converter transformer equipment in the actual operation.

The invention relates to the field of insulation electrical strength evaluation, and particularly discloses a method for evaluating the oil paper insulation electrical strength of a converter transformer through alternating-current and direct-current voltage superposition. Comprising the following steps: step S01, collecting breakdown voltage data of an oil paper insulation sample; step S02, analyzing breakdown strength distribution of the oil paper insulation sample; step S03, analyzing breakdown characteristics of an unaged oil paper insulation sample; step S04, analyzing breakdown characteristics of a thermally aged oil paper insulation sample; s06, outputting a breakdown characteristic analysis result of the oil-paper insulation sample, and analyzing the influence of alternating-current and direct-current voltage superposition and thermal aging on the breakdown characteristic; according to the method, the breakdown performance of the oil paper insulating material under the alternating current / direct current superposed voltage and thermal aging conditions is deeply analyzed, the influence on the performance of the oil paper insulating material is obtained, and a theoretical basis is provided for optimization and reliability improvement of insulating materials in a high-voltage direct current system and a converter transformer.

The present invention belongs to the field of transformer valve-side outlets, and specifically discloses a variable resistivity ultra-high voltage valve-side outlet device, characterized in that it includes: a rising seat, a voltage-equalizing ball fixed inside the rising seat, a valve-side sleeve with its tail end inserted into the voltage-equalizing ball, and a shielding tube with its head inserted into the voltage-equalizing ball; the outside of the voltage-equalizing ball is provided with an insulating layer, an inner insulating part, and an outer insulating part in sequence, an insulating oil channel is provided between the insulating layer and the inner insulating part, and an insulating oil channel is provided between the inner insulating part and the outer insulating part. A variable resistivity ultra-high voltage valve-side outlet device in the present invention adopts a combination of a voltage-equalizing ball, an insulating layer, an inner insulating part, and an outer insulating part to effectively reduce the DC and AC electric field strengths on the surface of the voltage-equalizing ball, reduce the DC creepage field strength on the surface of the insulating layer, the surface of the inner insulating part, and the surface of the outer insulating part, and ensure the electrical strength and insulation reliability of the voltage-equalizing ball.

The present application relates to a kind of high uniformity transformer insulating paperboard dynamic forming process and integrated preparation system, belong to transformer insulating material processing technical field, the system includes multiple-source modification module, ultrasonic fluidization module, dynamic reconfiguration module and gradient compaction module.Processing steps cover: slurry is carried out electromagnetic polarization and is compounded nanofiber to break flocculation;In the sizing stage, microflow beam treatment is carried out by applying ultrasonic field;In the forming net part, Z-axis interpenetration interweaving is generated by pulse vacuum induction fiber;Finally, temperature gradient formed by multistage temperature control press roller guides moisture migration and completes compaction.The present application introduces electric physical intervention and fluctuation pressure field, realizes the accurate control of fiber from micro-dispersion to three-dimensional reconstruction, effectively solves the problem of insufficient interlaminar bonding force and tightness of insulating paperboard, improves the electrical strength and mechanical robustness of transformer insulating component.

This invention relates to a transformer body unit and an electromagnetic voltage transformer device. The transformer body unit includes an iron core element, a first coil element and a second coil element respectively housed on the lower and upper parts of the iron core element, a first shielding element and a second shielding element respectively housed on the first coil element and the second coil element, and a lower insulating element and an upper insulating element respectively housed on the first shielding element and the second shielding element. Its advantages are: by utilizing the upper and lower insulating elements, optimal electric field distribution is obtained, making the transformer device capacitive, effectively avoiding resonance between the electromagnetic voltage transformer device and circuit breaker capacitance, line-to-ground distributed capacitance, etc., ensuring the safe operation of the power grid; by using the transformer body unit, the diameter of the porcelain bushing unit can be reduced, reducing oil weight and overall weight; the upper and lower insulating elements give the product good electrical strength and insulation performance as well as a low dielectric loss factor; overcoming the disadvantages of unstable performance, poor transient performance, and small output capacity.

The utility model discloses an electrical strength measuring device for insulating materials, which comprises an upper cabinet body and a lower cabinet body integrally formed with the upper cabinet body, the lower cabinet body is provided with casters, the top end of the upper cabinet body is provided with a measuring tool groove and a flip cover hinged with the measuring tool groove, and the flip cover is in magnetic attraction connection with the upper cabinet body after being turned over; an auxiliary drawer and an accessory drawer are sequentially arranged at the front end of the upper cabinet body from top to bottom; a maintenance tool drawer and a strength measurement tool storage cabinet are sequentially arranged at the front end of the lower cabinet body from top to bottom; the lower cabinet body is provided with a rotation limiting structure used for limiting the maintenance tool drawer from being pulled out. The strength measuring tool storage cabinet is provided with a hinged door, and the hinged door is provided with a rotary closing piece used for closing. By adopting the design of the classified drawers and the cabinet body, a plurality of measuring instruments such as high-voltage testers, maintenance tools and the like can be placed in a classified manner, so that the tools are prevented from being disordered; and by adopting the movable design, the device can be transferred in a short distance in a field, and is convenient and practical.

The application discloses a Teflon insulating material product and a preparation method thereof. The method comprises the following steps: mixing and calendering polytetrafluoroethylene fine powder, perfluoroalkoxy resin micro powder, polymethyl methacrylate flaky particles and liquid processing aids, and performing embossing treatment on one side of the mixture to obtain a main body insulating layer strip; then, inner layer strip and outer layer strip are prepared, and the inner layer strip and the outer layer strip are combined into a blank through multi-layer staggered winding; subsequently, the polymethyl methacrylate flaky particles are removed through staged heat treatment to form cavities, and the cavity edges are closed, and finally, the Teflon insulating material product is obtained. The product is internally formed with a discrete closed microcavity structure which is continuously staggered and distributed along the length direction, and has low dielectric constant, low dielectric loss, high electrical strength and high partial discharge inception voltage.

The invention discloses a device and method for testing the voltage breakdown performance of a cable in a high-temperature environment, and belongs to the technical field of electrical insulation, the device comprises an insulation bin, the two sides of the insulation bin are fixedly connected with an access bin and an outlet bin respectively, connecting holes are formed in the connecting positions of the access bin and the insulation bin and the connecting positions of the outlet bin and the insulation bin, and the connecting holes are communicated with the insulation bin. An insulating base is arranged at the bottom in the insulating bin, two grooves are formed in the upper surface of the insulating base, a supporting bracket is clamped in each groove, the upper parts of the supporting brackets are in contact with a cable to be tested, a conductive mechanism is arranged on the front side of the insulating base, and the conductive mechanism is connected with the insulating base. According to the test equipment, the voltage breakdown phenomenon of the cable under the real use condition can be simulated, the obtained test data is closer to the real use condition, and the electrical strength performance of the cable insulation material can be better evaluated.

The utility model provides a pressure sensor with high electrical strength, and relates to the technical field of sensors, the pressure sensor comprises a housing, the housing is internally provided with an inner cavity and a pressure sensing channel, and the pressure sensing channel is communicated with the inner cavity; the pressure sensing core body is arranged in the inner cavity; the circuit board is arranged in the inner cavity, and one end of the circuit board is connected with the pressure sensing core body; the connector assembly comprises a connector assembly body and a conduction piece located in the connector assembly body, one end of the connector assembly body is connected with one end of the shell, and one end of the conduction piece is connected with the other end of the circuit board; the conducting layer is located in the inner cavity and arranged on the periphery of the circuit board and the periphery of the pressure sensing core body, and at least part of the conducting layer makes contact with the circuit board; and the insulating layer is located in the inner cavity and wraps the periphery of the conductive layer, and the pressure sensor has good electrical strength and durability.

The utility model discloses a device for manufacturing an electrical strength sample of electrical porcelain pug. The device comprises a pressing handle located above equipment, an upper forming pressing die and a lower forming die located below the equipment. And the lower forming die is opposite to the upper forming pressing die above the lower forming die. The lower end of the upper forming pressing die is of a disc type structure, an arc protrusion is arranged in the center of the bottom, and a layer of gypsum inner wall is arranged on the surface of the cylindrical inner cavity of the lower forming die to form an integrated structure. The technical process is simple, pug is cut in a rotary fettling mode, the pug is easy to separate, the size of a sample is regular, the sample is easy to separate from a lower forming die with a gypsum inner wall after being repaired, the shape is regular and uniform, the tested electrical strength data is relatively stable, the electrical performance level of pug of different electrical porcelain formulas can be effectively evaluated, and the production efficiency is improved. The quality of the disc-shaped suspension type porcelain insulator is further improved by guiding the design of an electric porcelain formula, and the method is better applied to an ultra / extra-high voltage power transmission project.

The invention discloses a high-current copper core conductor polypropylene insulation medium-voltage power cable, belongs to the technical field of cable processing, and is used for solving the technical problem that the insulativity and thermal aging resistance of a polypropylene insulation medium-voltage power cable in the prior art need to be further improved. The cable specifically comprises a copper conductor, a conductor shielding layer and an insulating layer which are sequentially arranged from inside to outside. By optimizing the polypropylene insulating layer, the electrical strength, mechanical strength and heat aging resistance of the polypropylene insulating layer are effectively improved, and the conductor shielding layer, the metal shielding layer and the flame-retardant wrapping layer are introduced into the multi-layer structure outside the high-purity fillet copper conductor, so that the comprehensive performance of the medium-voltage power cable is remarkably improved, and the service life of the medium-voltage power cable is prolonged. The technical effects of enhancing current carrying, prolonging the service life of the cable and improving the operation safety are achieved.

The invention provides a preparation method of insulating flat paper for a high voltage grade, which belongs to the technical field of insulating product production and comprises the following steps: removing iron from slurry with the mass percentage concentration of 3-4%, adding the slurry into hydrochloric acid, stirring, washing until the mass percentage concentration is 3-4%, adding magnesium bicarbonate, stirring, and drying to obtain the insulating flat paper for the high voltage grade. The preparation method comprises the following steps: stirring, washing, deslagging, pulping and deironing, diluting to the mass percentage concentration of 0.3%-0.8%, purifying, carrying out jet molding at the linear velocity ratio of (1.1-1.7): 1 to obtain wet paper, controlling the gram weight of the wet paper to be 50-200gsm, carrying out vacuum suction dehydration and squeezing, drying to the dryness of 55-65% to form semi-wet paper, and squeezing and drying again to form the finished product flat paper. The use amount of hydrochloric acid is 0.5%-1.5% of the mass fraction of the slurry, and the addition amount of magnesium bicarbonate is 2%-2.5% of the mass fraction of the slurry, so that the technical problems that pure slurry is easily polluted and the phenomenon of breakdown caused by insufficient electric strength still occurs under high voltage in the existing flat paper preparation method are solved.

The invention discloses an electrical strength prediction method for converter transformer oil paper insulation at different service times and temperatures, and relates to the technical field of monitoring analysis, and the method comprises the steps: collecting the electrical strength data of the converter transformer oil paper insulation at different service times and temperatures, and building an initial data set; preprocessing the initial data set to obtain a preprocessed data set; based on the preprocessed data set, establishing a relation model among the electrical strength, the service time and the temperature by adopting a machine learning algorithm; training and optimizing the relation model by using a cross validation method to obtain an optimal electrical strength prediction model; and using the optimal electrical strength prediction model to predict the electrical strength of the oil paper insulation of the converter transformer at different service times and temperatures, and outputting a prediction result. The method has the effect of improving the prediction accuracy.

The invention relates to the technical field of power cable insulating materials, and discloses a compression-resistant insulating power cable material, a preparation method and a power cable, the insulating material comprises the following raw materials: low density polyethylene, ethylene propylene diene monomer, N, N '-m-phenylenedimaleimide, 2-mercaptobenzimidazole, zinc stearate, zinc methacrylate and dicumyl peroxide. In the preparation process, N, N '-m-phenylenedimaleimide and 2-sulfydryl benzimidazole are subjected to an in-situ addition reaction to generate a macromolecular crosslinking precursor, and free sulfydryl masking is realized. The precursor and zinc methacrylate are subjected to coordination to form polar nodes, and a homogeneous cross-linked network containing electron deep traps and dynamic sacrificial bonds is constructed after cross-linking and curing. Under the condition that no inorganic filler is added, irreversible slippage and space charge accumulation of macromolecular chain segments in an insulator are effectively inhibited, so that the cable material has high compression resistance, low creep deformation, high electrical strength and long-acting thermo-oxidative aging resistance.

The invention relates to an insulating material as well as a preparation method and application thereof. The insulating material is prepared from the following raw materials in parts by mass: 30 to 50 parts of co-polypropylene, 5 to 25 parts of heat-resistant polypropylene, 30 to 50 parts of polyolefin thermoplastic elastomer and 0.2 to 0.4 part of antioxidant. According to the invention, copolymerized polypropylene, heat-resistant polypropylene, polyolefin thermoplastic elastomer and antioxidant interact and synergistically interact under specific components and proportions, so that the technical problem that toughness and heat resistance are difficult to consider when polypropylene is used in the field of insulating materials for high-voltage cables is solved; the prepared insulating material has high heat resistance, high mechanical toughness and excellent electrical strength, avoids the phenomena of softening, deformation or cracking of the insulating layer due to heating, and meets the material requirements of high-voltage cables.

The application discloses a kind of parallel layer electrical strength test methods of fiber reinforced epoxy resin insulating pipe, comprising: obtaining the parallel layer sample of multiple fiber reinforced epoxy resin insulating pipes;On each parallel layer sample, a plurality of equal-diameter circular holes are uniformly opened;The parallel layer sample is placed in transformer oil, the transformer oil is heated to preset temperature, and the voltage is gradually increased to the circular hole of the parallel layer sample Breakdown;The median value of the voltage of the circular hole breakdown of multiple parallel layer samples is used as the value of the electrical strength of the parallel layer of the fiber reinforced epoxy resin insulating pipe.Solve the problem that the electrical strength of the fiber reinforced epoxy resin insulating pipe for ultra-high voltage electrical equipment is higher, and the existing standard specifies that the test method is difficult to effectively determine.

The utility model discloses a pressure sensor, which comprises a base component, the base component comprises a base and a pressure sensing component, the pressure sensing component comprises an elastic frame and a silicon strain gauge, the elastic frame comprises an elastic sheet, the elastic sheet is fixedly connected with the silicon strain gauge, and the silicon strain gauge is fixedly connected with the base. A circuit blocking piece is arranged between the base and the pressure sensing component, and the base, the circuit blocking piece and the pressure sensing component are fixedly connected. The circuit blocking piece blocks circuit conduction between the elastic piece and the base, the risk that electronic components are damaged is reduced, and the electrical strength of the product is improved.

The application discloses a kind of method and device for detecting the electrical strength of polypropylene film, belong to electrical strength detection technical field, its device includes test platform, lower foil, mask, test film, upper foil, first reel group, second reel group and third reel group, and the mask is provided with through-hole;Its method includes that upper foil is electrified, makes upper foil embed mask through-hole under the action of electrostatic force, then continues to boost, until test film is broken down, records the voltage and breakdown position when breakdown, after breakdown, the relative position of lower foil, test film, upper foil and mask through-hole is adjusted by first reel group, second reel group and third reel group.The application is realized by first reel group, second reel group and third reel group that lower foil, test film and upper foil are replaced automatically, so as to solve the technical problem that electrode needs to be manually wiped by technical personnel after multiple tests in prior art, effectively reduce the work burden of technical personnel.

The present invention relates to a 220 kV transformer lead clamping structure for a middle outlet, belonging to the technical field of transformers. The technical scheme is as follows: a top-connected trapezoidal paperboard (1) is a double trapezoidal shape with two upper bottom edges connected together by a rectangular plate (10), the two trapezoids are bent toward the same side of the rectangular plate (10), the two lower bottom edges of the top-connected trapezoidal paperboard (1) are tied to a bottom paperboard (2) by a shrink band (8), the bottom paperboard (2) is tied to a transformer body (9) by multiple polyester binding bands (7), the high-voltage lead (4) is fixed to a rectangular plate between the two upper bottom edges of the top-connected trapezoidal paperboard (1) by a winged U-shaped fixing plate (5) and an insulating screw (6), and a flat paperboard (3) is provided between the winged U-shaped fixing plate (5) and the rectangular plate between the two upper bottom edges of the top-connected trapezoidal paperboard. The beneficial effects of the present invention are: the structure is simple and can meet the requirements of mechanical properties and electrical strength.

The application discloses a kind of high surface natural micropore structure regulation-based high surface withstand voltage polyimide and preparation method and application thereof, belong to high voltage insulating material technical field, after drying diamine is dissolved in solvent A, then add dianhydride, after stirring uniformly, obtain polyamide acid solution;Add pore forming agent again, high-speed stirring is uniformly dispersed, obtain mixed viscous solution C;After coating, drying, imidization high temperature heating, and natural cooling, immerse in liquid B and extract pore forming agent, after drying, obtain high surface natural micropore structure regulation-based high surface withstand voltage polyimide.The polyimide surface has natural pore structure, surface is along the surface of electric field, and the through-hole structure is densely distributed along the surface of electric field, and the electron is easy to drop into the through-hole structure in the jumping multiplication process when flashover, and it is difficult to return to the surface, so that the secondary electron multiplication process is inhibited, the probability of forming secondary electron avalanche is reduced, so as to realize the improvement of surface withstand voltage.

The utility model relates to a high-precision automatic detection device for electric strength between commutator segments, and relates to the technical field of commutators, the high-precision automatic detection device comprises a feeding assembly, a clamping jaw assembly, a detection assembly and a discharging assembly, the clamping jaw assembly is used for clamping a material on the feeding assembly to the detection assembly for detection and clamping the material to the discharging assembly for discharging after detection is completed; wherein the detection assembly comprises an air bag type detector, a first electric cylinder and a second electric cylinder, the air bag type detector is provided with a detection groove, the shape of the detection groove corresponds to the shape of a product, the first electric cylinder and the second electric cylinder are vertically arranged above the detection groove and below the detection groove respectively, a driving shaft of the first electric cylinder faces the detection groove, and a driving shaft of the second electric cylinder faces the detection groove. And a driving shaft of the second electric cylinder extends into the detection groove. The detection assembly is matched with the feeding assembly, the clamping jaw assembly and the discharging assembly to automatically detect the electric strength between commutator segments, errors caused by manual detection can be avoided, and the detection efficiency can be improved on the basis of saving manpower.

The invention discloses a glass cloth single-side reinforced dry mica tape, which structurally comprises a glass cloth layer, a modified adhesive layer containing polyimide powder, a mica paper layer and an epoxy adhesive layer in sequence, and is characterized in that 2-8wt% of surface modified polyimide powder is added into a basic adhesive of the modified adhesive layer to improve the electrical performance of the mica tape; the preparation method comprises the steps of polyimide powder surface modification, modified adhesive preparation, coating and compounding, secondary coating, stepped curing and the like. The mica powder tape provided by the invention is suitable for high-voltage motor main insulation with higher requirements on the electrical strength of the glass cloth single-side reinforced less-rubber mica powder tape.

The embodiment of the invention discloses a power system power flow visualization method and device, equipment and a storage medium. According to the technical scheme provided by the embodiment of the invention, the power flow drawing of the power system is acquired, the plurality of power system components in the power flow drawing of the power system, the position information of the power system components and the connecting lines among the plurality of power system components are determined, and the point location acquisition data of the acquisition point locations bound with the power system components are acquired; the method comprises the following steps: acquiring point position data of a power system assembly, determining flow direction information and electrical strength information of each connecting line according to the point position acquisition data, displaying the power system assembly according to the position information, and displaying the connecting lines according to the flow direction information and the electrical strength information, the power system network can be flexibly established according to the real-time power system state, the change of the power system is responded in time, and the power flow analysis effect of the power system is improved.

The utility model provides a high temperature high pressure pulse cable for nuclear power station, include: single copper conductor and cross -linked polyimide insulating layer of extruding on copper conductor constitute insulating wire core, there is tinned copper wire double -layer weaving outside insulating wire core, adopt the outer sheath of cross -linked polyethylene material and extrude in weaving layer outside. The utility model in the conductor adopts single copper conductor to reduce the gap discharge under high pressure, because the conductor outer diameter is consistent, reduces the attenuation, guarantees the stability of signal transmission, the cross -linking technology adopts electron irradiation process in insulating layer, improves the temperature resistance grade, the radiation resistance of cable and the uniformity of cross -linked polyimide medium, reduces the loss of medium transmission, strengthens the electric strength, the weaving layer adopts the double shielding of double -layer copper wire weaving, can effectively shield the outside interference, guarantees the smooth transmission of signal, the outer sheath adopts cross -linked polyethylene sheath material, improves the heat resistance, the insulating property and corrosion resistance of cable.

The utility model belongs to the technical field of transformers, and provides a transformer switch resistor assembling structure which comprises an anchoring part fixedly connected to the side wall of a transformer body, and the anchoring part is electrically connected with a transformer switch. The switch resistor fixing part is fixedly connected to the side wall of the transformer body through the anchoring part, the switch resistor fixing part is electrically connected with the transformer switch through the anchoring part, the switch resistor fixing part is used for fixedly connecting a plurality of switch resistors, and the switch resistors are electrically connected with the switch resistor fixing part. According to the utility model, the requirement on the installation space can be reduced, and the problems of mutual interference and electrical strength caused by no space when the switch potential resistor is installed at the lower part of the switch can be effectively avoided.

The invention relates to the technical field of electrical strength testing, in particular to a vacuum insulating material electrical strength testing device. Comprising a vacuum cavity provided with a vacuum gauge and a test cable, electrode ends of a tested sample and the test cable are arranged on the inner side of the vacuum cavity, one end of the tested sample is connected with the electrode end of the test cable, and the other end of the tested sample is arranged on a mobile grounding assembly; the vacuum assembly comprises a molecular pump and a proportional valve which are respectively communicated with the vacuum cavity, and a first isolating valve is communicated between the molecular pump and the vacuum cavity. The sample to be tested is placed in the vacuum cavity, the voltage module, the molecular pump, the first isolation valve and the proportional valve are controlled through the controller, the vacuum environment is directly simulated in the vacuum cavity, the problem that the surface of the sample is polluted due to the fact that insulating oil is used in a traditional method is solved, the sample is free of pollution, and follow-up recycling and reusing are facilitated.

The application discloses a kind of composite core, stator and outer rotor permanent magnet synchronous motor, including main body core unit, core insulation composite unit A and core insulation composite unit B;Core insulation composite unit A includes core A, the corresponding end of the main body core unit corresponds with the core A, and its inner surface is in contact with the corresponding end surface of main body core unit, and its outer surface is integrally coated with insulator A;Core insulation composite unit B includes core B, the corresponding end of the main body core unit corresponds with the core B, and its inner surface is in contact with the corresponding end surface of main body core unit, and its outer surface is integrally coated with insulator B;The application effectively reduces the axial insulation thickness between coil winding and core end under the premise of guaranteeing electrical strength, and then effectively reduces the winding length and winding resistance, improves the working efficiency of its application motor, while it can improve the insulation stability and insulation life of its application motor.