Some standard content:
ICS29.180
Machinery Industry Standard of the People's Republic of China
JB/T5356--2002
Replaces JB/T5356--1991
20030958
Test guide for current transformers testPublished on July 16, 2002
Implementation on December 1, 2002
Published by the State Economic and Trade Commission of the People's Republic of ChinaForeword:
Normative referenced documents
3 Test conditions..
Sealing performance test
Oil-immersed transformer.
4.2SF. Gas insulated transformer
Outlet terminal marking inspection
Polarity table test method
Insulation resistance measurement
Power frequency withstand voltage test of primary winding
Power frequency withstand voltage test between winding sections..
Power frequency withstand voltage test of secondary winding and end (ground) screenPartial discharge measurement.
Capacitance and dielectric loss factor (tan) measurement11.1
Standard environmental conditions
Test method,
Volt-ampere characteristic measurement,
Test equipment,
Test method
Turn-to-turn overvoltage test
Error determination
Insulating oil performance test
Short-time current test
Operation,
Test circuit.
Test preparation,
Winding connection of multi-ratio transformer||tt ||Secondary current measurement
Visual inspection..
Inspection of insulation in contact with the conductor surface
Temperature rise test.
Rated lightning impulse test and operating impulse testWet test of outdoor transformer
Cut-off lightning impulse test
Mechanical strength test
Compound error test
JB/T5356—20O2
JB/T5356—2002
23 Transient error test
24 Radio interference test
Insulation thermal stability test
Type test report,
Type test cycle and requirements
JB/T5356-2002
This standard proposes guiding test methods for the test items specified in GB1208-1997 "Current Transformer". This standard replaces JB/T5356-1991.
Compared with JB/T5356-1991, the main changes of this standard are as follows: the provisions on test cycle are added;
The provisions on SF. Gas insulated transformers are added: radio interference and other contents are added:
Some test circuit diagrams are modified and supplemented. This standard is proposed by China Machinery Industry Federation. This standard is under the jurisdiction of the National Technical Committee for Instrument Transformer Standardization. The drafting units of this standard are: Shenyang Transformer Research Institute, Wuhan High Voltage Research Institute, Shenyang Shenbian Instrument Transformer Manufacturing Co., Ltd., Baoding Tianwei Baobian Electric Co., Ltd., Shenyang Instrument Transformer Factory (Co., Ltd.), Dalian Instrument Transformer Factory, Shanghai Instrument Transformer Factory, Jiangsu Jingke Instrument Transformer Company.
The main drafters of this standard are: Lu Wanlie, Guo Keqin, Yin Shian, Chi Yongjiu, Tong Mingyuan, Li Fugen, and Wang Jinliang. This standard was first issued in 1991.
1 Scope
Guidelines for current transformer testing
JB/T5356—2002
This standard specifies the test conditions, test equipment and instruments, test methods, test data processing, etc. of current transformers (hereinafter referred to as transformers).
This standard applies to current transformers with a rated frequency of 50Hz (or 60Hz) for use in electrical measuring instruments and electrical protection devices. 2 Normative references
The clauses in the following documents become clauses of this standard through reference in this standard. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties to an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For any undated referenced document, the latest version shall apply to this standard. GB311.1--1997 Insulation coordination of high-voltage transmission and transformation equipment (neqpositive EC60071-1: 1993) GB/T507-1986 Dielectric strength determination method of insulating oil (neqEC60156) GB1208-1997 Current transformer (eqvEC60185: 1987) GB/T GB/T7252-2001
GB/T7600-1987
GB/T11023-1989
GB/T11604-1989
GB16847-1997
Measurement of relative dielectric constant, dielectric loss factor and volume resistivity of liquid insulating materials at power frequency (neqpositive EC Guidelines for analysis and judgment of dissolved gases in transformer oil (negIEC60599:1999) Measurement of moisture content in transformer oil during operation Stable method (coulomb method) Test method for sulfur hexafluoride gas sealing of high-voltage switchgear Test method for radio interference of high-voltage electrical equipment (eqvEC60018: 1983) Technical requirements for transient characteristics of current transformers for protection (idtEC60044-6: 1992) GB/T16927.1-1997
High voltage test technology Part 1: General test requirements (eqvIEC60060-1: 1989) High voltage test technology Part 2: Measurement system (eqvEC60060-2: 1994) GB/T16927.2-1997
GB/T 17443-—1998
Technical parameters and requirements of 500kV current transformer JJG313-1994 Current transformer for measurement
3 Test conditions
This chapter is the requirements for general test items. If there are no other provisions for specific test items, they should be carried out in accordance with this chapter. 3.1: The ambient temperature is 5℃～40℃ (unless otherwise specified). 3.2 There should be no significant difference between the temperature of the test product and the ambient temperature. 3.3 The test site shall not be affected by obvious AC or DC external electromagnetic fields. 3.4 The test should be carried out on assembled products. 3.5. The standard transformer used in the test should comply with the requirements of JJG3131994. 3.6 The test site must have separate working grounding and protective grounding, and a protective fence must be set up. 3 .7. The distance between the test piece and the grounding body or adjacent objects should generally be greater than 1.5 times the minimum air distance between the high-voltage part of the test piece and the grounding part. 3.8 General test requirements and measurement system regulations shall be in accordance with GB/T16927.1-1997 and GB/T16927.2-1997. 4 Sealing performance test
4.1 Oil-immersed transformer
4.1.1 Main equipment:
JB/T5356-2002
a) Gas compression device;
b) Filter:
Pressure reducing valve and gas transmission pipe;
Inflating or oiling device, and the inflation or oiling device shall be equipped with a check valve and a pressure gauge, and the accuracy level of the pressure gauge shall not be lower than d)
2.5 level.
The product must be left to rest before the test, and the resting time shall be in accordance with Table 1.
Equipment Highest Voltage
Root Mean Square Value
Minimum Static Time Before Test
Applied Pressure
Maintained Pressure
Minimum Residual Pressure of Gas Pressurization
Products without Expander
Products with Expander Test without Expander
Also Suitable for Outdoor Combined Transformers
The Sealing Performance Test must be conducted on clean products, and the test site must be free of obvious oil stains. An inflation or oil injection device should be installed to inject a certain pressure of dry gas into the oil-immersed transformer product without expander from a single direction. The pressure and maintenance time should not be less than the specified value in Table 1. Or oil,)
4.1.5·For oil-immersed transformers with expanders, the transformer should be tested for sealing performance according to the above method before the expander is installed. After the test is qualified, the expander should be installed and filled with oil, and then it should be static for 12 hours. After testing at the pressure and time specified in Table 1, observe whether the product has oil seepage or air leakage. 4.1.6
For products with expanders, after being left to rest for the specified time, check the appearance to see if there is oil seepage or leakage. 4.1.7
For products with explosion-proof disks, measures should be taken to meet the test pressure in Table 1. 4.2SF. Gas-insulated transformer
SF The sealing test of gas-insulated transformer shall be carried out in accordance with the provisions of GB/T11023-1989: SF. The annual gas leakage rate shall be less than 1%. 5 Inspection of terminal markings
5.1 Polarity
The letter markings of the transformer primary winding and secondary winding terminal shall be correct and clear. The polarity between the transformer primary winding and the secondary winding is subtractive polarity.
5.2 Polarity table test method
5.2.1 Voltage (current) method See Figure 1.
The positive pole of the battery is connected to the P1 terminal of the primary winding, and the negative pole is connected to the P2 terminal of the primary winding: the positive pole of the DC ammeter is connected to the S1 terminal of the secondary winding, and the negative pole is connected to the S2 terminal of the secondary winding. At the moment of turning on the switch, the ammeter swings in the clockwise direction, and the transformer is of subtractive polarity. 5.2.2 The method of using error checker to check the transformer shall be carried out in accordance with the relevant provisions of JJG313-1994. 6 Insulation resistance measurement
Test equipment: insulation resistance meter (its specifications are determined according to the product technical conditions). 6.2 Test method. Before measurement, the insulation resistance meter shall be subjected to an open circuit and short circuit test to check whether the insulation resistance meter is in good condition. Before and after the measurement 2
JB/T5356-2002
, the transformer under test shall be fully discharged to ensure the safety of equipment and personnel. First, short-circuit the outlets of the primary winding or secondary winding of the transformer, and place the insulation resistance meter in a horizontal position. If the megohmmeter is used for measurement, the pointer should be adjusted to the "αo" position at approximately the rated speed (120r/min), and then the line end (L) of the insulation resistance meter shall be connected to the winding under test, and the ground wire shall be connected to other windings and the metal base or box shell, and rotate at a uniform speed for 1 minute, while recording the ambient temperature and humidity.
6.3 Other testers can also be used for measurement. 6.4 Regardless of the method used, the test results shall comply with the product technical conditions. 7 Power frequency withstand voltage test of primary windingbzxZ.net
7.1 The distance between the test product and the grounding body or adjacent objects shall not be less than 1.5 times the minimum air distance between the high-voltage part and the grounding part of the test product. The relative humidity of the test site shall be less than 80%. 7.2 See Figure 2 for the test circuit. If there is an end (ground) screen, it should be connected to the metal base or box shell and grounded - Test transformer: Cr, C. - Capacitor voltage divider: T - Test transformer:
R - Protective resistor; V-
Peak voltage meter.
7.3 After confirming that the equipment circuit and power supply waveform are correct, apply voltage to the test product. When applying pressure, the voltage should be slowly increased from the mechanical 0 position, and the instrument voltage increase value should be observed. When the test voltage is increased to 75%, the voltage is increased to the test value of the short-time power frequency withstand voltage at a rate of 2% of the test voltage per second, maintained for 1 minute or the specified time, and then reduced to 30% of the specified test voltage before cutting off the power supply. 7.4 If there is no destructive discharge during the test, the test is qualified. 8 Power frequency withstand voltage test between winding sections
8.1 See Figure 3 for the test circuit.
8.2 The applied voltage increases from 0, and after it reaches the specified test voltage value, it lasts for 1 minute, and then drops to 30% of the specified test voltage before cutting off the power supply.
8.3 If there is no breakdown, the test is qualified. TV - voltage regulator: T - test transformer; A - ammeter; RV. RMS voltmeter; V2
peak voltmeter: T,—
9 Power frequency withstand voltage test for secondary winding and end (ground) screen 9.1 See Figure 4 for the test circuit.
Protective resistor:
One transformer under test.
9.2 The applied voltage should be increased from the mechanical 0 position, and after it reaches the specified test voltage value and lasts for 1 minute, it should be reduced to below 30% of the test voltage value and then the power supply should be cut off. Transformers with multiple secondary windings should be tested in sequence. 3
JB/T5356—2002
Voltage regulator: T
Test transformer: A
—Root mean square value voltmeter: V2
9.3 If there is no breakdown phenomenon, the test is qualified. Partial discharge measurement
Ammeter: R-
Protective resistor:
Peak voltage meter; T transformer under test.
Partial discharge measurement shall be carried out in accordance with the relevant provisions of GB1208—1997. Capacitance and dielectric loss factor (tan6) measurement 11
11.1 Standard environmental conditions
Relative humidity is not more than 60%;
Test sample temperature is 10℃～30℃.
11.2 Test method
11.2.1 Chain type current transformer
The test voltage is applied to the short-circuited primary winding terminals. The test circuit is shown in Figure 5.
11.2.2. Capacitor type current transformer
Voltage regulator: V
Peak voltage meter: T
Test transformer: C
Chuang measuring bridge,
Test transformer: H-
Standard capacitor: CI, C2
Metal base or box shell is grounded.
A bridge:
Capacitor voltage divider.
The test voltage is applied to the short-circuited primary winding terminals, and the secondary windings are short-circuited and connected to the metal base or box shell and grounded. The end (ground) of the primary winding capacitor screen is connected to the bridge. The test circuit is shown in Figure 6.
Voltage regulator: V
Peak voltage meter: T
Test transformer: C.
Test transformer: H
Standard capacitor: CI, C2
Bridge:
A capacitor voltage divider.
12 Measurement of volt-ampere characteristics
12.1 Test equipment
Average value voltmeter (1.0 level)
Electromagnetic AC ammeter (0.5 level);
Auto-coupling voltage regulator (with sufficient capacity).
12.2 Test method
12.2.1 Test circuit
The test circuit is shown in Figure 7.
JB/T5356—2002
12.2.2 Test method
Apply voltage to both ends of the winding under test, read the voltage value based on the excitation current reading, and when testing a certain group of windings, the other windings are in an open circuit state, and each group of secondary windings is tested in turn, as shown in Figure 7. Other methods can also be used. During the test, attention should be paid to the errors caused by the shunt and voltage division of the meter. When the measured voltage is higher than the power frequency withstand voltage value of the secondary winding, a low-frequency test power supply must be used. After measuring the voltage value, current value and actual measured frequency, the voltage value should be converted to the value when the power supply is 50Hz. The conversion method is as follows: U = (U/50) fx
Where:
U——measured voltage value, unit is V:
Table 1—measured frequency, unit is Hz.
13 Turn-to-turn overvoltage test
-voltage regulator: V-
average value voltmeter: A
This test is only applicable to current transformers without short-circuit turn compensation. Ammeter: T
Tested transformer.
Test methods and requirements shall comply with the relevant provisions of GB1208-1997. See Figure 8 (Method A) or Figure 9 (Method B) for the test circuit diagram. TV
Voltage regulator:
Voltage regulator: T
Test transformer: V
Test transformer:
Peak voltage meter:
Peak voltage meter:
Amperemeter: T
Amperemeter: Work
Test transformer.
Test transformer,
JB/T5356—2002
14 Error determination
14.1 Error determination shall be carried out in accordance with the provisions of JJG313--1994. When measuring the error, attention should be paid to the following:
a) The sum of the resistances of the two secondary wires connected to the tested transformer shall be equal to the specified value, which is the reserved resistance of the load box (usually 0.062 or 0.052) minus the active load caused by the test instrument to the tested transformer, and the error shall not exceed 3%. b
The sum of the resistances of the two wires connecting the secondary winding of the standard transformer should be equal to its specified value, which is the rated load of the standard transformer (cos@=1) minus the load caused by the tester on the standard transformer (cos@=1), and the error should not exceed ±3%. c) The primary wire of the test busbar transformer should be ensured to be in the center of the transformer. 14.2. The demagnetization method of the transformer should be carried out according to the demagnetization method marked on the nameplate of the manufacturer or specified in the technical documents. If the manufacturer does not make any regulations, you can choose a suitable method from the methods described below for demagnetization according to the specific situation. a) Open circuit demagnetization method
Select a winding with fewer turns in the primary (or secondary) winding and pass it with 10% of the rated primary (or secondary) current. When the other windings are open-circuited, the current is steadily and slowly reduced to 0. During the demagnetization process, the peak voltage meter connected to the two ends of the winding with the most turns should be monitored. When the indicated value exceeds 2600V, demagnetization should be carried out at a smaller current. b) Closed circuit demagnetization method
Connect a resistor equivalent to 10 to 20 times the rated load to the secondary winding (considering sufficient capacity), pass the power frequency current to the primary winding, increase from 0 to 1.2 times the rated current, and then evenly and slowly reduce it to 0. When demagnetizing a current transformer with two or more secondary windings, one of the secondary windings is connected to a demagnetizing resistor and the remaining secondary windings are short-circuited.
15 Insulating oil performance test
The insulating oil performance test is carried out in accordance with relevant standards such as GB/T507-1986, GB/T5654-1985, GB/T7252-2001 and GB/T7600--1987.
The insulating oil performance indicators are shown in Table 2.
Highest voltage of equipment
363~550
16 Short-time current test
16.1 Operation
Breakdown voltage is not less than
tan (90℃) is not greater than
Water content is not greater than
Hydrogen content is not greater than
According to the provisions of 4.2.5 and 4.5.1 of GB1208-1997, the product test should simulate the normal installation and operation state. 16.2 Test circuit
The test circuit is shown in Figure 10.
16.3 Test preparation
This test generally requires the provision of a primary impedance value, so the primary impedance of the test product should be measured before the test. 16.4 Winding connection of multi-ratio transformers
For short-time current tests on multi-ratio transformers, the transformer lead terminals shall be wired according to the short-time current value specified in the product technical specifications that gives the primary winding the maximum current density. a) When the transformer has the same number of primary windings connected in series or parallel to change the current ratio, if only one short-time current rating is specified (which must be met for any ratio), the test shall be carried out under the minimum current ratio wiring mode. 6
JB/T5356—2002
If several different short-time current ratings are specified, and the ratio of these short-time current ratings corresponds to the ratio of the rated primary current when the primary winding is connected in different series and parallel connections (for example: a transformer can obtain three current ratios by connecting the primary winding in series, series-parallel, and parallel, and the ratio of its rated primary current is 1:2:4, and the ratio of the short-time current rating is also 1:2:4), then the test should be carried out under the maximum current ratio connection mode (primary winding parallel connection): If it does not correspond to the above relationship, the test should be carried out under the primary winding connection mode corresponding to the minimum current ratio (primary winding single connection). b) For transformers that use primary winding taps to change the current ratio, the connection mode with the largest primary winding short-time thermal current density should be selected for testing.
If the short-time thermal current density of the primary winding is the same under various connection modes, the test should be carried out under the maximum primary current connection mode. c) When the transformer has a secondary winding tap to change the current ratio, the secondary terminal with the smallest current ratio should be short-circuited. 16.5 Secondary current measurement
During the short-time current test, the secondary current should be measured simultaneously. For transformers with multiple secondary windings, the winding with the largest secondary current multiple can be selected for measurement, and the remaining windings are short-circuited. Note: The maximum secondary current multiple is defined as: when the secondary winding is short-circuited; when the transformer core magnetic flux density reaches the saturation state, the ratio of the secondary current to the rated secondary current (provided by the commissioned tester) 16.6 Visual inspection
For transformers with detachable primary and secondary winding structures, in addition to checking the appearance, an internal body inspection is also required, and photographic records are taken. For transformers cast in epoxy resin, generally only the appearance is inspected. The disassembly inspection should be presided over by the test supervisor engineer. 16.7 Inspection of insulation in contact with the conductor surface For transformers with copper windings, the short-time current density shall be calculated according to d) of 4.5.1 of GB1208-1997. The actual cross-sectional area of the conductor shall be used for calculation (if measurement is not possible, the design cross-sectional area may be used instead). Powered by a network or impulse generator
Temperature rise test
1S11S2
- Measurement standard current transformer: T:
17.1 The test shall be carried out in accordance with the provisions of 4.2.6 and 4.5.2 of GB1208-1997. 17.2 The test circuit is shown in Figure 11.
T2 Current booster: A
Test transformer.
Ammeter; R——Load: T
Figure: 11
Test transformer.
17.3 Environmental requirements: There should be no factors that affect the ambient temperature around the test site, such as radiation, heat source, airflow, etc. Two or three thermometers should be used to measure the ambient temperature, and the temperature measuring end should be immersed in a cup filled with oil with a volume of not less than 1000mL. Place it 1m2m around the test sample, and the height is about the middle of the test sample. The ambient temperature is based on the average value of several thermometers.5 Secondary current measurement
During the short-time current test, the secondary current should be measured simultaneously. For transformers with multiple secondary windings, the winding with the largest secondary current multiple can be selected for measurement, and the other windings are short-circuited. Note: The maximum secondary current multiple is defined as: when the secondary winding is short-circuited; when the flux density of the transformer core reaches the saturation state, the ratio of the secondary current to the rated secondary current (provided by the commissioned tester) 16.6 Visual inspection
For transformers with detachable primary and secondary winding structures, in addition to checking the appearance, internal body inspection is also required, and photographic records are taken. For transformers cast in epoxy resin, generally only the appearance is checked. The disassembly inspection should be presided over by the test supervisor engineer. 16.7 Inspection of insulation in contact with the surface of the conductor For transformers with copper windings, the short-time current density is calculated according to d) of 4.5.1 in GB12081997. The actual measured conductor cross-sectional area is used for calculation (when measurement is not possible, the design cross-sectional area calculation can also be used instead). Powered by network or impulse generator
Temperature rise test
1S11S2
A measurement standard current transformer: T:
17.1 The test shall be carried out in accordance with the provisions of 4.2.6 and 4.5.2 of GB1208-1997. 17.2 The test circuit is shown in Figure 11.
T2 Current riser: A
Tested transformer.
Current meter; R——Load: T
Figure: 11
Tested transformer.
17.3 Environmental requirements: There shall be no factors that affect the ambient temperature around the test site, such as radiation, heat source, airflow, etc. Two or three thermometers shall be used to measure the ambient temperature, and the temperature measuring end shall be immersed in a cup filled with oil with a volume of not less than 1000mL. Place it 1m2m around the test object, at a height approximately in the middle of the test object. The ambient temperature is based on the average value of several thermometers.5 Secondary current measurement
During the short-time current test, the secondary current should be measured simultaneously. For transformers with multiple secondary windings, the winding with the largest secondary current multiple can be selected for measurement, and the other windings are short-circuited. Note: The maximum secondary current multiple is defined as: when the secondary winding is short-circuited; when the flux density of the transformer core reaches the saturation state, the ratio of the secondary current to the rated secondary current (provided by the commissioned tester) 16.6 Visual inspection
For transformers with detachable primary and secondary winding structures, in addition to checking the appearance, internal body inspection is also required, and photographic records are taken. For transformers cast in epoxy resin, generally only the appearance is checked. The disassembly inspection should be presided over by the test supervisor engineer. 16.7 Inspection of insulation in contact with the surface of the conductor For transformers with copper windings, the short-time current density is calculated according to d) of 4.5.1 in GB12081997. The actual measured conductor cross-sectional area is used for calculation (when measurement is not possible, the design cross-sectional area calculation can also be used instead). Powered by network or impulse generator
Temperature rise test
1S11S2
A measurement standard current transformer: T:
17.1 The test shall be carried out in accordance with the provisions of 4.2.6 and 4.5.2 of GB1208-1997. 17.2 The test circuit is shown in Figure 11.
T2 Current riser: A
Tested transformer.
Ammeter; R——Load: T
Figure: 11
Tested transformer.
17.3 Environmental requirements: There shall be no factors that affect the ambient temperature around the test site, such as radiation, heat source, airflow, etc. Two or three thermometers shall be used to measure the ambient temperature, and the temperature measuring end shall be immersed in a cup filled with oil with a volume of not less than 1000mL. Place it 1m2m around the test object, at a height approximately in the middle of the test object. The ambient temperature is based on the average value of several thermometers.
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