High precision vulcanized rubber voltage breakdown tester ASTM standard

Voltage breakdown phenomenon

The breakdown theory of solid media:

Electric breakdown of solid media refers to the phenomenon where the dielectric is directly damaged and loses its insulation properties solely due to the action of an electric field.

There are a small number of electrons (conduction electrons) in the conduction band level in solid media, which accelerate under strong electric fields and constantly collide with atoms (or ions) at lattice nodes. When the energy obtained by conducting electrons from the electric field per unit time is greater than the energy lost during collision, the number of conducting electrons will rapidly increase when the energy of the electrons reaches a level that can ionize the lattice atoms (or ions), causing electron avalanche and damaging the lattice structure of the solid medium, resulting in a significant increase in conductivity and breakdown.

When the conductivity (or dielectric loss) of the medium is small, there are good heat dissipation conditions, and there is no partial discharge inside the medium, the breakdown of solid media is usually electrical breakdown, and its breakdown field strength can generally reach 105-106kV/m, which is much higher than that of thermal breakdown, which is only 103-104kV/m.

The main characteristics of electrical breakdown are that the breakdown voltage is almost independent of the surrounding environmental temperature, and except for short periods of time, the relationship between breakdown voltage and voltage application time is not significant; The medium does not generate significant heat; The uniformity of the electric field has a significant impact on the breakdown voltage.

The main factors affecting the breakdown voltage of solid dielectrics

○ Voltage application time

If the solid dielectric is broken down when the applied voltage is applied for a short period of time (such as less than 1/10s), then this breakdown is likely to be electrical breakdown. If the voltage is applied for a long time (several minutes to tens of hours) to cause breakdown, it is often thermal breakdown. Sometimes it is difficult to distinguish between the two, for example, when the test sample is broken down in a 1-minute AC withstand voltage test, it is often due to the dual effects of electricity and heat. When the voltage is applied for several tens of hours or even years before breakdown, it mostly belongs to electrochemical breakdown. In order to accurately determine the cause of breakdown, specific analysis should also be conducted based on the breakdown phenomenon, rather than simply measuring it by time.

○ Uniformity of electric field

The breakdown voltage of solid media in a uniform electric field is often high and increases approximately linearly with the increase of dielectric thickness; If the thickness of the dielectric increases in an uneven electric field, the electric field will become more uneven, and the breakdown voltage will no longer linearly increase with the increase of thickness. When the increase in thickness makes heat dissipation difficult to the point where it may cause thermal breakdown, the significance of increasing thickness becomes even smaller.

○ Temperature

Electrical equipment with solid dielectric as insulation material, if the local temperature is too high in a certain area, there is a risk of thermal breakdown under operating voltage. The heat resistance and heat resistance level of different solid dielectric materials are different, so the critical temperature at which they transition from electrical breakdown to thermal breakdown is generally different.

○ Moisture

The impact of moisture on the breakdown voltage of solid media is related to the properties of the material. For polar media that are prone to moisture absorption, such as cotton yarn, paper, and other fiber materials, the breakdown voltage after moisture absorption may only be a few percent or lower than when dry, due to a significant increase in conductivity and dielectric loss. Therefore, when manufacturing high-voltage insulation structures, attention should be paid to removing moisture, moisture-proof measures should be taken during operation, and the moisture situation should be checked regularly.

○ Cumulative effect

Electrical equipment that mainly uses solid media as insulation materials may experience a decrease in breakdown voltage due to cumulative effects as the number of impulse or power frequency test voltages increases. Therefore, when determining the number of times to apply voltage and the test voltage value during the withstand voltage test of such electrical equipment, this cumulative effect should be considered, and when designing solid insulation structures, a certain insulation margin should be ensured.

High precision vulcanized rubber voltage breakdown tester ASTM standardScope of application:

Insulating plastics, films, and film products

Insulating plastics are mainly thermosetting plastics. An insulating film is a thin film that can ensure good electrical insulation. This type of film generally has high electrical resistivity (above 1010 Ω· cm) and breakdown field strength. In order to be used for high-frequency insulation, it is also required that the material has low dielectric loss.

Insulated mica products

Mica sheets, mica paper, etc. made of mica are used as insulation materials for electrical equipment and electrical devices.

Organic insulating materials

Cordyceps, resin, rubber, cotton yarn, paper, hemp, silk, artificial silk, etc. are mostly used to manufacture insulation paint, coating insulation materials for winding wires, etc.

Inorganic insulation materials

Asbestos, marble, ceramics, glass, etc. are mainly used as winding insulation for motors and electrical appliances, as well as bottom plates and insulators for switches.

Insulated fiber products, laminated products, etc.

Including insulation paper, insulation cardboard, paper tubes, and various fiber fabrics such as insulation yarn, tape, rope, tube, etc. A layered electrical insulation material made by impregnating or coating different adhesives with fiber paper and cloth as substrates, and then hot pressing and rolling them.

Impregnated insulation material

Including lacquered silk, lacquered cloth and glass lacquered cloth, insulated lacquered pipes, etc.

High precision vulcanized rubber voltage breakdown tester ASTM standardApplicable standards:

GB/T 1408.1-2016 "Test Methods for Electrical Strength of Insulation Materials Part 1: Test at Power Frequency"

GB/T 1408.2-2016 "Test Methods for Electrical Strength of Insulation Materials Part 2: Additional Requirements for Application of DC Voltage Test"

JJG 795-2004 "Verification Regulations for Voltage Endurance Testers"

GB/T 1695-2005 "Determination method for power frequency breakdown voltage strength and withstand voltage of vulcanized rubber"

GB/T 3333-1999 "Test Method for Power Frequency Breakdown Voltage of Cable Paper"

GB/T 12913-2008 "Capacitor Paper"

ASTM D149 "Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulation Materials at Industrial Power Supply Frequency"

Product selection:

Product technical advantages:

Automatic discharge at the end of the experiment

After the experiment is completed, it will automatically discharge to ensure the personal safety of the operators.

Oil immersion test

Oil immersion test can avoid the phenomenon of creepage caused by air breakdown and misjudgment of breakdown.

Push pull window, safety door protection

High voltage operation protection, voltage can only be increased when the window is closed, the test process can be observed in real time, and the safety door automatically shuts off when opened to ensure the safety of operators.

One click switching for AC/DC testing

The software interface can switch between AC test and DC test with one click.

Real time display of experimental curves

During the experiment, the test curve can be dynamically drawn, and the test curve can be overlaid with multiple colors for comparison, locally enlarged, and any section of the curve can be analyzed by enlarging the area.

Modular system, automatic electrode alignment

Independent control system, modular structure, convenient for after-sales maintenance, and no noise throughout the entire experimental process.

The electrode automatically aligns and locates, making it easy to operate and achieving higher accuracy.

Special configuration options:

Multiple optional electrodes

The standard electrodes are two Φ 25 electrodes and one Φ 75 electrode, which can form a set of equal diameter electrodes and a set of unequal diameter electrodes. These two sets of electrodes have the widest range of applications, and there are also multiple electrode options available. Alternatively, you can provide relevant standards or drawings to support customized electrodes.

Optional high-temperature module

① Temperature range: Room temperature~90 ℃

Fuel tank material: Phenolic resin

Heating power: 1.5 kW

Fuel tank size: 300 × 400 × 200mm

Control accuracy: ± 1 ℃

Temperature gradient: ± 2 ℃

② Temperature range: Room temperature~300 ℃

Fuel tank material: marble

Heating power: 3kW

Fuel tank size: 300 × 400 × 200mm

Control accuracy: ± 1 ℃

Temperature gradient: ± 3 ℃

Touch screen optional

Optional touch screen configuration for easier operation.

The default configuration for stepless voltage regulation models is a touch screen.

Customizable high-frequency voltage

Customizable high-frequency voltage source: voltage waveform requirements (square wave, sine wave, etc.), maximum current requirements, frequency requirements (500Hz, 1kHz, etc.) need to be provided.

Typical users:

Testing and research institutions

China National Inspection and Testing Corporation (CTC)

Beijing Institute of Building Materials Inspection and Research

Youyan (Guangdong) New Materials Technology Research Institute

Guangdong Institute of Corrosion Science and Technology Innovation

Anhui Branch of China Electric Power Research Institute

Shanghai Electric Power Research Institute

Shenyang Product Quality Supervision and Inspection Institute

institutions of higher education

Northwestern Polytechnical University

Sichuan Agricultural University

Hunan University of Technology

Northeastern University

China University of Petroleum

North China Electric Power University

Huazhong University of Science and Technology

Beijing University of Chemical Technology

Zhejiang University

New Materials

Shanghai Wangxun New Materials Co., Ltd

Changzhou Qianli Electronic New Materials Co., Ltd

Shandong Silicon New Materials Co., Ltd

Zhejiang Huazheng New Materials Co., Ltd

Wankai New Materials Co., Ltd

Gaoren Electronic New Materials Co., Ltd

Shenzhen Rezdun New Materials Co., Ltd

Jiangxi Ganfeng Lithium Battery Technology Co., Ltd

Shanghai Anbitai New Materials Co., Ltd

Wires, cables, and power systems

Yangzhou Shuguang Cable Co., Ltd

TBEA (Deyang) Cable Co., Ltd

Jiangsu Shangshang Cable Group

Far East Cable Co., Ltd

Shanghai Qifan Cable Co., Ltd

State Grid Henan Luoyang Power Supply Company

Trade and Distribution

Wanju International (Hangzhou) Supply Chain Co., Ltd

Guang'an Hengxin Medical Equipment Co., Ltd

Changzhou Zhurui Scientific Instrument Co., Ltd

Hunan Huisheng Trading Co., Ltd

Changsha Lusheng Instrument Equipment Co., Ltd

Hunan Blue Star Electronic Technology Co., Ltd

Shaanxi Hongxin Experimental Instrument Co., Ltd

Suzhou Renyi Machinery Tools Co., Ltd

Henan Zhongyibao Industrial Co., Ltd

Jinan Yuejun Economic and Trade Co., Ltd

Jiangxi Bochen Automation Equipment Co., Ltd