JB/T 3282-1999 Test method for determining the relative resistance of solid insulating materials to surface discharge breakdown

This standard specifies the test method for the relative resistance to surface discharge breakdown of solid insulating materials. This standard is applicable to the assessment of the relative resistance to breakdown of solid insulating materials when exposed to surface discharge. JB/T 3282-1999 Test method for determining the relative resistance to surface discharge breakdown of solid insulating materials JB/T3282-1999 Standard download decompression password: www.bzxz.net

JB/T3282-1999
This standard is a revision of JB3282-83 "Test Method for Relative Surface Discharge Breakdown Performance of Solid Insulating Materials". Compared with JB3282-83, this standard has modified its writing format and improved its technical content according to IEC60343:1991.
This standard will replace JB3282-83 from the date of implementation. This standard is proposed and managed by the National Technical Committee for Standardization of Insulating Materials. The drafting units of this standard: Guilin Electric Science Research Institute, Xi'an Jiaotong University, Harbin Large Electric Machinery Research Institute. The drafter of this standard: Wei Jun.
This standard was first issued on November 24, 1983 and revised for the first time in 1999. This standard is entrusted to the National Technical Committee for Standardization of Insulating Materials for interpretation. Scope
Mechanical Industry Standard of the People's Republic of China
Test methods for determining the relative resistance of insulating meterials to breakdown by surface discharges
Test methods for determining the relative resistance of insulating meterials to breakdown by surface discharges This standard specifies the test method for the relative resistance of solid insulating materials to breakdown by surface discharges. This standard is applicable to the assessment of the relative resistance of solid insulating materials to breakdown when exposed to surface discharges. Cited standards
JB/T3282-1999
eqvIEC60343:1991
Replaces JB3282-83
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of the standard, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T10580--1989 Standard conditions for solid insulating materials before and during testing (eqvIEC60212:1971) IEC60060
IEC60270:1981
3 Principle
High voltage test technique
Partial discharge measurement
When solid insulating materials are exposed to electric field strengths of industrial frequencies and produce surface discharges, some simple methods are needed to assess their relative resistance to surface discharge and breakdown. Experience has shown that if dry circulating air is used around the electrodes and on the surface of the specimen during the test, surface discharges are produced using several different types of electrodes, and endurance tests with complete breakdown of the material as the criterion can obtain similar and reproducible classifications of materials with respect to this type of stress.
4 Apparatus
4.1 Test electrodes
The test should use a stainless steel cylindrical electrode and a flat plate electrode. The exact grade of stainless steel is not important. However, these electrodes shall meet the following requirements:
4.1.1 Cylindrical electrode
A cylinder with a diameter of 6+0.3 mm and an edge with a radius of 1 mm. The weight of this electrode shall not exceed 30 g and shall be placed vertically on the surface of the specimen. For soft materials, a gap of not more than 100 μm between this electrode and the specimen is allowed to prevent possible mechanical damage.
For very thin specimens (thickness less than 100 μm), it is more convenient to place it between two electrodes with a fixed distance of 100 μm.
When small specimens must be used to reduce their capacitive heating, cylindrical electrodes with a diameter of less than 6 mm and an edge with a radius of 1 mm are allowed.
JB/T3282-1999
Figure 1 shows two examples of electrode arrangements that can be used. When a gap between the upper electrode and the specimen is not required, the device shown in Figure 1b may be used to prevent the electrode from tilting slightly, or other suitable devices may be used. 4.1.2 Flat Electrode
The area of ​​the flat electrode shall be greater than the area covered by the discharge of the cylindrical electrode at the test voltage. 4.1.3 Electrode Arrangement
The electrode arrangement shall have axisymmetry. The air inlet shall be located so that the air distribution to the various electrodes is as uniform as possible to ensure good reproducibility of the results. One or more electrodes may be tested on a specimen. If multiple electrodes are used, the distance between the electrodes shall be such as to prevent the discharge between adjacent electrodes from interfering with each other and shall not be less than 50 mm (see Figure 2). 4.2 Specimens
The specimens shall be tested on specimens having one or more of the following nominal thicknesses (i.e. 3.0, 1.6, 1.0 mm and 500, 100, 25 μm). For each nominal thickness, nine specimens (i.e. nine specimen surfaces exposed to the discharge) shall be tested at each voltage. The sample should have a suitable area to avoid flashover and have a uniform thickness that meets the nominal deviation. The upper surface of the sample subjected to discharge should be free of contamination.
To avoid possible micro-discharges between the sample and the flat electrode, a conductive electrode must be added to the lower surface of the sample. It should be noted that the selected electrode material must not affect or significantly change the performance of the sample. The following materials can usually be used:
a) Vacuum-plated chrome, silver or gold. The sample must be conditioned after the electrode is added; b) Tin foil or aluminum foil. The thickness is 0.025mm and the same area as the sample. Use suitable vaseline oil or silicone grease to stick it to the sample. The amount of grease used should be as small as possible. It must be prevented that the grease sticks to the other side of the sample, and the grease will not have a harmful effect on the sample due to chemical degradation;
c) Conductive silver paint.
The test must be carried out on a sample that has been treated according to GB/T10580 and has reached complete equilibrium. Note: Special tests can be carried out on a laminate of thin film materials, but the results are mostly inconsistent with the test results of the same material with a single layer of equal thickness. 4.3 Test conditions
The test is usually carried out on a stress-free specimen. However, the specimen can also be subjected to mechanical stress simultaneously during the discharge process; a tensile force can be applied, or a thin sheet specimen can be bent on a curved electrode. When mechanical stress is applied, the deformation of hard materials should be 0.5%, and that of soft materials should be 5%.
Usually, the test should be carried out in dry air with a relative humidity not exceeding 20% ​​(a relative humidity of 20% or less can be obtained by passing the air through a drying column containing a suitable desiccant, such as CaCl). The air should be sufficiently dry and its flow rate should be large enough to ensure that the life measured under the test conditions is not affected by the local concentration of degradation products. Tests have shown that an air flow rate of 0.5Vmin is more appropriate. Notes
1 The test is usually carried out at a temperature of 23±2℃. It can also be carried out at other temperatures. For example, the test is carried out at the operating temperature of the test material or in accordance with GB/T10580.||t t||2 In special cases, the test can be carried out in other media. 3 In order to prevent the possible damage to health caused by the active gases (such as O and NO in the air), it is recommended to test in a closed container so that the air flows through the sample 32
and then directly discharged from the laboratory.
4.4 Test voltage
4.4.1 Frequency and waveform of test voltage
JB/T3282—1999
It is recommended to test at industrial frequency (48~62Hz). If the test is carried out at a higher frequency, the functional relationship between the durability of the test material and the frequency under the test conditions should be determined to calculate Output its equivalent durability at power frequency. If the test is carried out at power frequency, it is necessary to report the calculated life at power frequency and the test life measured at the test frequency. The voltage at power frequency or higher frequency should be approximately sinusoidal, and the ratio of its peak value to the effective value should be less than ±5%. The test voltage does not contain harmonics with an amplitude exceeding 5%. (See EC60060). At the same frequency and other conditions, at least three voltage points should be used to determine the change in life with external applied voltage. The highest test voltage should be selected to make the sample life equivalent to not less than 100h at power frequency; the lowest test voltage should be selected to make the sample life equivalent to not less than 5000h at power frequency. h.
For thin specimens (thickness less than 100um), the minimum test voltage allowed to be selected is equivalent to 1000h at the power frequency. Nine specimens are tested at the same time, and the test ends when the fifth one breaks down. The breakdown value is the median value. 4.4.2 Routine acceptance tests are carried out on previously evaluated materials. The test life at frequency f should be measured at a voltage predetermined based on previous material research, so that the material is equivalent to being destroyed in one year at the power frequency.
For thin materials (thickness less than 100μm), the test voltage should be selected so that the expected life is 1000h at the power frequency. 5 Electrical equipment
5.1.High voltage power supply
The step-up transformer, voltage regulator, circuit breaker and voltage voltmeter used for testing at power frequency 48~62Hz shall comply with the provisions of IEC60060.
For testing at higher frequencies, a generator, transformer or electronic oscillator with appropriate power output may be used. 5.2 End point control device
If dry air circulates over the specimen, a short interruption of the test voltage (a few minutes) has almost no effect on the life. Therefore, when the specimen under one electrode is destroyed, the circuit breaker is allowed to operate and the test power is cut off and the clock used to record the test time is stopped at the same time. However, it is more convenient to connect a fuse or circuit breaker in series with each test electrode, so that the test time of each specimen can be recorded. A suitable fuse device consists of a 0.03mm thin copper wire connected in series with the high voltage electrode. The fuse is connected between a pin and the movable arm of a micro switch connected to the timing device.
The resistance in series with each specimen should never exceed 10K. Note: Care should be taken that when one specimen is broken and/or the circuit is disconnected, no disturbance should occur to the remaining specimens due to possible voltage fluctuations. 6 Procedure
The test equipment shall comply with the requirements of Chapter 4.
Prepare the specimen as described in 4.2 and place it on or between the electrodes as described in 4.1. Apply a voltage between the upper and lower electrodes using electrical equipment that complies with the requirements of Chapter 5. Measure surface discharge using any of the methods described in IEC 60270. The provisions of the test conditions should include the following aspects: a) Whether type inspection or routine inspection is required: 33
b) Method of measuring test thickness;
JB/T3282-1999
c) If the number of samples tested at each voltage is greater than nine, the number of tests should be specified; d) The gap between the upper surface of the sample and the rod electrode; e) The contact method between the sample and the flat electrode (such as vacuum aluminum plating, silver paint); f) If the test temperature is not 23±2℃, the test temperature should be specified; g) If the test medium is not air, the specific medium should be specified; h) If the relative humidity of the test environment is greater than 20%, the specific relative humidity should be specified; i) The level and type of mechanical stress applied to the sample during the entire test: i) Test frequency;
k) Is the test voltage selected to make the test life equivalent to the power frequency at least 100h or 5000h. 7 Factors to be considered
When the specimen is exposed to discharge conditions, the process of rapid reduction in the durability of the insulation with increasing stress is related to the type and thickness of the insulation and the temperature of the surrounding medium. It should be noted that the data are only comparable when exactly the same electrode arrangement is used and other test conditions remain unchanged.
7.1 Insulation thickness
The electric field strength (E) at which the surface discharge occurs at the beginning of the durability test is a function of the insulation thickness and the relative dielectric constant. During the test, the value of E changes and its initial value should be determined. Using thickness as a parameter, the relationship between the applied electric field strength E and the test life can be determined to determine the effect of thickness on durability (see Figure 3a). For the discharge of a round rod electrode to an insulating plate, the test life decreases with the increase of the EE ratio. Thinner specimens tend to decrease faster than thicker specimens. Plotting a graph of the relationship between E/E and the test life of a material can provide a better understanding of its discharge resistance. (See Figure 3b).
E and E are the values ​​obtained by dividing the applied voltage and the discharge starting voltage by the average specimen thickness, respectively. 7.2 Ambient temperature
The discharge resistance of many materials decreases with increasing temperature. 7.3 Mechanical stress
Tensile stress can reduce the discharge resistance of many materials. However, compressive stress does not seem to have a significant effect. 7.4 Humidity
The conductive film formed in a humid atmosphere can reduce the discharge capacity and cause chemical degradation. 7.5 Air pressure
Increase in air pressure can increase the initial surface discharge voltage. However, if a discharge occurs at this time, the test life will be shortened due to the stronger discharge.
7.6 Frequency
If the frequency is too high, the accumulated heat can cause thermal breakdown, so that the voltage endurance calculated using high-frequency measurement is shorter than the test life measured at power frequency.
7.7 Conductive surface layer
The conductive surface layer can be formed more quickly at higher frequencies than at power frequency. It affects the discharge characteristics and often forms periodic or complete discharge extinction. Therefore, the voltage durability converted to the power frequency in the test at a higher frequency may be much higher than the actual measurement at the power frequency.
Test report
The test report should include the following:
a) Manufacturer's description and marking of the material, including model, name, additives (if known); b) Sample preparation method and pretreatment conditions; c) Nominal thickness of the sample and measured thickness range; d) Number of samples tested at each voltage;
e) Electrode weight (if not 30g, indicate it); f) Gap between the sample and the electrode;
g) High-voltage electrode (if the diameter is not 6mm, indicate it) h) Test medium: air or other gases; i) temperature and pressure of the upper electrode;
i) humidity and gas velocity on each sample; k) nature and magnitude of mechanical stress applied during the test: 1) test voltage frequency:
m) breakdown time of all failed samples at each test voltage at the test frequency used. If the test frequency is not 48~62Hz, it should also be noted that these values ​​correspond to the calculated values ​​at the power frequency; n) if possible, the maximum discharge capacity (in PC) at the beginning of the electrical aging test at each test voltage; o) graphical representation of test results. Surface discharge life curve represented by the electric field strength E versus the median test life (see Figure 3a). The graph can be drawn on semi-logarithmic or logarithmic paper. In addition, it can be represented by E/E, as shown in Figure 3b. xDetails
a) Example of using a single cylindrical electrode
b) Using two non-inclined electrodes with joints 1 High-voltage electrode; 2 A guide sleeve with high-voltage electrode wiring (other methods are also possible); 3 A fastening screw for adjusting the electrode gap (other methods are also possible); 4 A lower part of the high-voltage electrode (when necessary); 5 An air nozzle (e.g. made of PVC); 6 A test sample; 7 A low-voltage electrode; 8 Figure 1 Electrode arrangement
Electrode holder (e.g. made of mica glass plate) 35
JB/T3282-1999
Clamping assembly
Figure 2 Electrode arrangement
Surface discharge: Influence of material thickness on its durability at 21C. 19
5×101×10
5x1011x10t
Lifetime at 50Hz
Figure 3a Lifetime curve on semi-logarithmic graph
High voltage electrode 6±0.3
Mica glass plate
Sample clamping load
Low voltage electrode
Mica glass plate
5×10*1×105×10*1×105×10=1×10*[h]
Lifetime at 50Hz
Figure 3b Lifetime curve on logarithmic graph1. Use electrical equipment that meets the requirements of Chapter 5 to apply voltage between the upper and lower electrodes. Measure surface discharge using any of the methods described in IEC60270. The provisions of the test conditions should include the following aspects: a) Whether type inspection or routine inspection is required: 33
b) Method of measuring test thickness;
JB/T3282-1999
c) If the number of samples tested at each voltage is greater than nine, the number of tests should be specified; d) The gap between the upper surface of the sample and the rod electrode; e) The contact method between the sample and the flat electrode (such as vacuum aluminum plating, silver paint); f) If the test temperature is not 23±2℃, the test temperature should be specified; g) If the test medium is not air, the specific medium should be specified; h) If the relative humidity of the test environment is greater than 20%, the specific relative humidity should be specified; i) The level and type of mechanical stress applied to the sample during the entire test: i) Test frequency;
k) Is the test voltage selected to make the test life equivalent to the power frequency at least 100h or 5000h. 7 Factors to be considered
When the specimen is exposed to discharge conditions, the process of rapid reduction in the durability of the insulation with increasing stress is related to the type and thickness of the insulation and the temperature of the surrounding medium. It should be noted that the data are only comparable when exactly the same electrode arrangement is used and other test conditions remain unchanged.
7.1 Insulation thickness
The electric field strength (E) at which the surface discharge occurs at the beginning of the durability test is a function of the insulation thickness and the relative dielectric constant. During the test, the value of E changes and its initial value should be determined. Using thickness as a parameter, the relationship between the applied electric field strength E and the test life can be determined to determine the effect of thickness on durability (see Figure 3a). For the discharge of a round rod electrode to an insulating plate, the test life decreases with the increase of the EE ratio. Thinner specimens tend to decrease faster than thicker specimens. Plotting a graph of the relationship between E/E and the test life of a material can provide a better understanding of its discharge resistance. (See Figure 3b).
E and E are the values ​​obtained by dividing the applied voltage and the discharge starting voltage by the average specimen thickness, respectively. 7.2 Ambient temperature
The discharge resistance of many materials decreases with increasing temperature. 7.3 Mechanical stress
Tensile stress can reduce the discharge resistance of many materials. However, compressive stress does not seem to have a significant effect. 7.4 Humidity
The conductive film formed in a humid atmosphere can reduce the discharge capacity and cause chemical degradation. 7.5 Air pressure
Increase in air pressure can increase the initial surface discharge voltage. However, if a discharge occurs at this time, the test life will be shortened due to the stronger discharge.
7.6 Frequency
If the frequency is too high, the accumulated heat can cause thermal breakdown, so that the voltage endurance calculated using high-frequency measurement is shorter than the test life measured at power frequency.
7.7 Conductive surface layer
The conductive surface layer can be formed more quickly at higher frequencies than at power frequency. It affects the discharge characteristics and often forms periodic or complete discharge extinction. Therefore, the voltage durability converted to the power frequency in the test at a higher frequency may be much higher than the actual measurement at the power frequency.
Test report
The test report should include the following:
a) Manufacturer's description and marking of the material, including model, name, additives (if known); b) Sample preparation method and pretreatment conditions; c) Nominal thickness of the sample and measured thickness range; d) Number of samples tested at each voltage;
e) Electrode weight (if not 30g, indicate it); f) Gap between the sample and the electrode;
g) High-voltage electrode (if the diameter is not 6mm, indicate it) h) Test medium: air or other gases; i) temperature and pressure of the upper electrode;
i) humidity and gas velocity on each sample; k) nature and magnitude of mechanical stress applied during the test: 1) test voltage frequency:
m) breakdown time of all failed samples at each test voltage at the test frequency used. If the test frequency is not 48~62Hz, it should also be noted that these values ​​correspond to the calculated values ​​at the power frequency; n) if possible, the maximum discharge capacity (in PC) at the beginning of the electrical aging test at each test voltage; o) graphical representation of test results. Surface discharge life curve represented by the electric field strength E versus the median test life (see Figure 3a). The graph can be drawn on semi-logarithmic or logarithmic paper. In addition, it can be represented by E/E, as shown in Figure 3b. xDetails
a) Example of using a single cylindrical electrode
b) Using two non-inclined electrodes with joints 1 High-voltage electrode; 2 A guide sleeve with high-voltage electrode wiring (other methods are also possible); 3 A fastening screw for adjusting the electrode gap (other methods are also possible); 4 A lower part of the high-voltage electrode (when necessary); 5 An air nozzle (e.g. made of PVC); 6 A test sample; 7 A low-voltage electrode; 8 Figure 1 Electrode arrangement
Electrode holder (e.g. made of mica glass plate) 35
JB/T3282-1999
Clamping assembly
Figure 2 Electrode arrangement
Surface discharge: Influence of material thickness on its durability at 21C. 19
5×101×10
5x1011x10t
Lifetime at 50Hz
Figure 3a Lifetime curve on semi-logarithmic graph
High voltage electrode 6±0.3
Mica glass plate
Sample clamping load
Low voltage electrode
Mica glass plate
5×10*1×105×10*1×105×10=1×10*[h]
Lifetime at 50Hz
Figure 3b Lifetime curve on logarithmic graph1. Use electrical equipment that meets the requirements of Chapter 5 to apply voltage between the upper and lower electrodes. Measure surface discharge using any of the methods described in IEC60270. The provisions of the test conditions should include the following aspects: a) Whether type inspection or routine inspection is required: 33
b) Method of measuring test thickness;
JB/T3282-1999
c) If the number of samples tested at each voltage is greater than nine, the number of tests should be specified; d) The gap between the upper surface of the sample and the rod electrode; e) The contact method between the sample and the flat electrode (such as vacuum aluminum plating, silver paint); f) If the test temperature is not 23±2℃, the test temperature should be specified; g) If the test medium is not air, the specific medium should be specified; h) If the relative humidity of the test environment is greater than 20%, the specific relative humidity should be specified; i) The level and type of mechanical stress applied to the sample during the entire test: i) Test frequency;
k) Is the test voltage selected to make the test life equivalent to the power frequency at least 100h or 5000h. 7 Factors to be considered
When the specimen is exposed to discharge conditions, the process of rapid reduction in the durability of the insulation with increasing stress is related to the type and thickness of the insulation and the temperature of the surrounding medium. It should be noted that the data are only comparable when exactly the same electrode arrangement is used and other test conditions remain unchanged.
7.1 Insulation thickness
The electric field strength (E) at which the surface discharge occurs at the beginning of the durability test is a function of the insulation thickness and the relative dielectric constant. During the test, the value of E changes and its initial value should be determined. Using thickness as a parameter, the relationship between the applied electric field strength E and the test life can be determined to determine the effect of thickness on durability (see Figure 3a). For the discharge of a round rod electrode to an insulating plate, the test life decreases with the increase of the EE ratio. Thinner specimens tend to decrease faster than thicker specimens. Plotting a graph of the relationship between E/E and the test life of a material can provide a better understanding of its discharge resistance. (See Figure 3b).
E and E are the values ​​obtained by dividing the applied voltage and the discharge starting voltage by the average specimen thickness, respectively. 7.2 Ambient temperature
The discharge resistance of many materials decreases with increasing temperature. 7.3 Mechanical stress
Tensile stress can reduce the discharge resistance of many materials. However, compressive stress does not seem to have a significant effect. 7.4 Humidity
The conductive film formed in a humid atmosphere can reduce the discharge capacity and cause chemical degradation. 7.5 Air pressure
Increase in air pressure can increase the initial surface discharge voltage. However, if a discharge occurs at this time, the test life will be shortened due to the stronger discharge.
7.6 Frequency
If the frequency is too high, the accumulated heat can cause thermal breakdown, so that the voltage endurance calculated using high-frequency measurement is shorter than the test life measured at power frequency.
7.7 Conductive surface layer
The conductive surface layer can be formed more quickly at higher frequencies than at power frequency. It affects the discharge characteristics and often forms periodic or complete discharge extinction. Therefore, the voltage durability converted to the power frequency in the test at a higher frequency may be much higher than the actual measurement at the power frequency.
Test report
The test report should include the following:
a) Manufacturer's description and marking of the material, including model, name, additives (if known); b) Sample preparation method and pretreatment conditions; c) Nominal thickness of the sample and measured thickness range; d) Number of samples tested at each voltage;
e) Electrode weight (if not 30g, indicate it); f) Gap between the sample and the electrode;
g) High-voltage electrode (if the diameter is not 6mm, indicate it) h) Test medium: air or other gases; i) temperature and pressure of the upper electrode;
i) humidity and gas velocity on each sample; k) nature and magnitude of mechanical stress applied during the test: 1) test voltage frequency:
m) breakdown time of all failed samples at each test voltage at the test frequency used. If the test frequency is not 48~62Hz, it should also be noted that these values ​​correspond to the calculated values ​​at the power frequency; n) if possible, the maximum discharge capacity (in PC) at the beginning of the electrical aging test at each test voltage; o) graphical representation of test results. Surface discharge life curve represented by the electric field strength E versus the median test life (see Figure 3a). The graph can be drawn on semi-logarithmic or logarithmic paper. In addition, it can be represented by E/E, as shown in Figure 3b. xDetails
a) Example of using a single cylindrical electrode
b) Using two non-inclined electrodes with joints 1 High-voltage electrode; 2 A guide sleeve with high-voltage electrode wiring (other methods are also possible); 3 A fastening screw for adjusting the electrode gap (other methods are also possible); 4 A lower part of the high-voltage electrode (when necessary); 5 An air nozzle (e.g. made of PVC); 6 A test sample; 7 A low-voltage electrode; 8 Figure 1 Electrode arrangement
Electrode holder (e.g. made of mica glass plate) 35
JB/T3282-1999
Clamping assemblyWww.bzxZ.net
Figure 2 Electrode arrangement
Surface discharge: Influence of material thickness on its durability at 21C. 19
5×101×10
5x1011x10t
Lifetime at 50Hz
Figure 3a Lifetime curve on semi-logarithmic graph
High voltage electrode 6±0.3
Mica glass plate
Sample clamping load
Low voltage electrode
Mica glass plate
5×10*1×105×10*1×105×10=1×10*[h]
Lifetime at 50Hz
Figure 3b Lifetime curve on logarithmic graph7 Conductive surface layer
The conductive surface layer can be formed faster at higher frequencies than at power frequency. It affects the discharge characteristics and often forms periodic or complete discharge extinguishing. Therefore, the voltage durability converted to power frequency in the test at higher frequencies may be much higher than the actual measurement at power frequency.
Test report
The test report should include the following:
a) Manufacturer's description and marking of the material, including model, name, additives (if known); b) Sample preparation method and pretreatment conditions; c) Nominal thickness of the sample and measured thickness range; d) Number of samples tested at each voltage;
e) Electrode weight (if not 30g, indicate); f) Gap between sample and electrode;
g) High-voltage electrode (if diameter is not 6mm, indicate) h) Test medium: air or other gases; i) temperature and pressure of the upper electrode;
i) humidity and gas velocity on each sample; k) nature and magnitude of mechanical stress applied during the test: 1) test voltage frequency:
m) breakdown time of all failed samples at each test voltage at the test frequency used. If the test frequency is not 48~62Hz, it should also be noted that these values ​​correspond to the calculated values ​​at the power frequency; n) if possible, the maximum discharge capacity (in PC) at the beginning of the electrical aging test at each test voltage; o) graphical representation of test results. Surface discharge life curve represented by the electric field strength E versus the median test life (see Figure 3a). The graph can be drawn on semi-logarithmic or logarithmic paper. In addition, it can be represented by E/E, as shown in Figure 3b. xDetails
a) Example of using a single cylindrical electrode
b) Using two non-inclined electrodes with joints 1 High-voltage electrode; 2 A guide sleeve with high-voltage electrode wiring (other methods are also possible); 3 A fastening screw for adjusting the electrode gap (other methods are also possible); 4 A lower part of the high-voltage electrode (when necessary); 5 An air nozzle (e.g. made of PVC); 6 A test sample; 7 A low-voltage electrode; 8 Figure 1 Electrode arrangement
Electrode holder (e.g. made of mica glass plate) 35
JB/T3282-1999
Clamping assembly
Figure 2 Electrode arrangement
Surface discharge: Influence of material thickness on its durability at 21C. 19
5×101×10
5x1011x10t
Lifetime at 50Hz
Figure 3a Lifetime curve on semi-logarithmic graph
High voltage electrode 6±0.3
Mica glass plate
Sample clamping load
Low voltage electrode
Mica glass plate
5×10*1×105×10*1×105×10=1×10*[h]
Lifetime at 50Hz
Figure 3b Lifetime curve on logarithmic graph7 Conductive surface layer
The conductive surface layer can be formed faster at higher frequencies than at power frequency. It affects the discharge characteristics and often forms periodic or complete discharge extinguishing. Therefore, the voltage durability converted to power frequency in the test at higher frequencies may be much higher than the actual measurement at power frequency.
Test report
The test report should include the following:
a) Manufacturer's description and marking of the material, including model, name, additives (if known); b) Sample preparation method and pretreatment conditions; c) Nominal thickness of the sample and measured thickness range; d) Number of samples tested at each voltage;
e) Electrode weight (if not 30g, indicate); f) Gap between sample and electrode;
g) High-voltage electrode (if diameter is not 6mm, indicate) h) Test medium: air or other gases; i) temperature and pressure of the upper electrode;
i) humidity and gas velocity on each sample; k) nature and magnitude of mechanical stress applied during the test: 1) test voltage frequency:
m) breakdown time of all failed samples at each test voltage at the test frequency used. If the test frequency is not 48~62Hz, it should also be noted that these values ​​correspond to the calculated values ​​at the power frequency; n) if possible, the maximum discharge capacity (in PC) at the beginning of the electrical aging test at each test voltage; o) graphical representation of test results. Surface discharge life curve represented by the electric field strength E versus the median test life (see Figure 3a). The graph can be drawn on semi-logarithmic or logarithmic paper. In addition, it can be represented by E/E, as shown in Figure 3b. xDetails
a) Example of using a single cylindrical electrode
b) Using two non-inclined electrodes with joints 1 High-voltage electrode; 2 A guide sleeve with high-voltage electrode wiring (other methods are also possible); 3 A fastening screw for adjusting the electrode gap (other methods are also possible); 4 A lower part of the high-voltage electrode (when necessary); 5 An air nozzle (e.g. made of PVC); 6 A test sample; 7 A low-voltage electrode; 8 Figure 1 Electrode arrangement
Electrode holder (e.g. made of mica glass plate) 35
JB/T3282-1999
Clamping assembly
Figure 2 Electrode arrangement
Surface discharge: Influence of material thickness on its durability at 21C. 19
5×101×10
5x1011x10t
Lifetime at 50Hz
Figure 3a Lifetime curve on semi-logarithmic graph
High voltage electrode 6±0.3
Mica glass plate
Sample clamping load
Low voltage electrode
Mica glass plate
5×10*1×105×10*1×105×10=1×10*[h]
Lifetime at 50Hz
Figure 3b Lifetime curve on logarithmic graph
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