Some standard content:
ICS29.180
China: Machinery Industry Standard of the People's Republic of China JB/T5357—2002
Replaces JB/T5357—1991
Test guide for voltage transformers test2002-07-16 Issued
2002-12-01 Implementation
Issued by the State Economic and Trade Commission of the People's Republic of China Foreword
Scope.
Normative references
Test conditions.
Sealing performance test.
4.1 Oil-immersed transformer
4.2SF. Gas insulated transformer
Terminal marking inspection
Polarity meter test method
Insulation resistance measurement..
Winding DC resistance measurement
Power frequency withstand voltage test and induction withstand voltage test of primary winding8.1
Power frequency withstand voltage test of primary windingWww.bzxZ.net
Induction withstand voltage test
Power frequency withstand voltage test between primary and secondary winding sections and secondary windingPartial discharge measurement
Excitation characteristic measurement.
Test circuit,
Test method.
Measurement of dielectric loss factor (tan6)
12.1 Standard environmental conditions
Test methods
Error determination
Insulating oil performance test
Temperature rise test
Short-circuit withstand capacity test.
Rated lightning impulse test and switching impulse testWet test of outdoor transformers
Cut-off lightning impulse test
Mechanical strength test
Radio interference test
Type test report
Type test cycle and requirements
JB/T5357—2002
JB/T5357—2002
This standard proposes guiding test methods for the test items specified in GB1207-1997 "Voltage Transformer". This standard replaces JB/T5357—1991.
Compared with JB/T53571991, the main changes of this standard are as follows: 1. Added the provisions on the test cycle:
Added the provisions on SF gas insulated transformers: Added the contents of radio interference, etc.:
Modified and supplemented some test circuit diagrams.
This standard is proposed by the 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, Shenyang Shenbian Instrument Transformer Manufacturing Co., Ltd., Shenyang Instrument Transformer Factory (Co., Ltd.), Dalian No. 1 Instrument Transformer Factory, Zhongshan Taihe Electromechanical Factory, Jingjiang Instrument Transformer Factory, Wenzhou Precision Instrument Transformer Factory. The main drafters of this standard are: Lu Wanlie, Jiang Jiawei, He Jianguang, Yuan Guosheng, Xiong Jiangyong, Chen Daji. This standard was first issued in 1991.
1 Scope
Guidelines for voltage transformer testing
JB/T53572002
This standard specifies the test conditions, test equipment and instruments, test methods, test data processing, etc. of voltage transformers (hereinafter referred to as transformers).
This standard applies to voltage transformers (electromagnetic type) with a rated frequency of 50Hz (or 60Hz) for supplying 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, the 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. GB311.11997 Insulation coordination of high voltage transmission and transformation equipment (neqIEC60071-1:1993) GB/T507—1986 Dielectric strength test method of insulating oil (nieqIEC60156) GR 1207—1997
Voltage transformer (eqvIEC60186:1987)GB/T5654-1985
Measurement of power frequency relative dielectric constant, dielectric loss factor and volume resistivity of liquid insulating materials (neqEC60247:1978)
GB/T7252-2001
GB/T7600—1987
GB/T11023—1989
GB/T11604—1989
Guidelines for analysis and judgment of dissolved gases in transformer oil (negpositiveC60599:1999) Determination of moisture content in transformer oil during operation (Coulomb method) Test method for sulfur hexafluoride gas sealing of high-voltage switchgear Test method for radio interference of high-voltage electrical equipment (eqvIEC60018: 1983) GB/T16927.1—1997 High voltage test technology Part 1: General test requirements (eqvIEC60060-1: 1989) GB/T16927.2—1997
High voltage test technology Part 2: Measurement system (eqvIEC60060-2: 1994) JG314—1994 Voltage transformer for measurement
Test conditions
This chapter is the requirements for general test items. If there is no other provision for specific test items, it shall be carried out in accordance with this chapter. 3.13
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 significantly affected by external electromagnetic fields of AC or DC. 3.4 The test should be carried out on the assembled product. 3.5 The standard transformer used in the test should meet the requirements of JG314-1994. 3.6 The test site must have separate working grounding and protective grounding, and a protective fence should 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. The general test requirements and measurement system regulations shall be in accordance with GB/T16927.1-1997 and GB/T16927.2-1997. Sealing performance test
4.1 Oil-immersed transformer
4.1.1 Main equipment:
Gas compression device;
JB/T53572002
Filter;
Pressure reducing valve and gas transmission pipe:
Gas charging or oil filling device, and the gas charging or oil filling device should be equipped with a check valve and a pressure gauge, the accuracy level of the pressure gauge should not be lower than d)
2.5 level.
The product must be left to rest before the test, and the rest time is in accordance with Table 1. 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 ExpanderTest 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. 4.1.3
4.1.4A charging or oiling device should be installed to inject a certain pressure of dry gas or oil into the oil-diffused transformer product without expander from the one-way valve, and the applied pressure and maintenance time should not be less than the specified values in Table 1. 4.1.5 For oil-immersed transformers with expanders, the transformers should be tested for sealing performance according to the above method before the expanders are installed. After the test is qualified, the expanders should be installed and filled with oil, and then left to stand for 12 hours. 4.1.6 After the pressure and time test specified in Table 1, observe whether the product has oil seepage or gas leakage. 4.1.7 For products with expanders, after being left to stand for the specified time, check the appearance for seepage or oil leakage. For products with explosion-proof disks, measures should be taken to meet the test pressure in Table 1. 4.2SF. Gas-insulated transformers
SF. The sealing test of gas-insulated transformers 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 Terminal marking inspection
5.1 Polarity
The letter markings of the transformer primary winding and secondary winding outlet terminals shall be correct and clear. The polarity between the transformer primary winding and secondary winding is negative polarity.
5.2 Polarity meter test method
5.2.1 Voltage (current) method See Figure 1.
The positive pole of the battery is connected to the A terminal of the secondary winding, and the negative pole is connected to the N (or B) terminal of the primary winding. The positive pole of the DC ammeter is connected to the a terminal of the secondary winding and the negative pole is connected to the n (or b) terminal of the secondary winding. At the moment the switch is turned on, the ammeter pointer swings clockwise, which is the negative polarity.
Residual voltage winding terminal mark inspection method. 5.2.2 The method of using error checker to check the transformer shall be carried out in accordance with the relevant provisions of JG314-1994. 2
6 Insulation resistance measurement
6.1 Test equipment: Insulation resistance meter (its specifications are determined according to product technical conditions). JB/T5357-2002
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. The transformer under test shall be fully discharged before and after the measurement to ensure the safety of equipment and personnel. First, short-circuit the output of the primary winding or secondary winding of the transformer, and place the insulation resistance meter in a horizontal position. If a megohmmeter is used for measurement, the pointer should be adjusted to the "co" position at approximately the rated speed (120r/min). Then connect the line end (L) of the insulation resistance meter to the tested winding, and the ground wire to other windings and the metal base or box shell, and rotate at a uniform speed for 1 minute. At the same time, record 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
Winding DC resistance measurement
7.1 Test conditions: temperature range is 5℃～40℃, relative humidity is less than 80%. When it is necessary to measure resistance greater than or equal to 102, a single-arm bridge should be used for measurement. 7.2
7.3 Resistance less than 102, a double-arm bridge should be used for measurement. 7.4 The ambient temperature should be measured accurately during measurement, and the resistance value should be corrected to the reference temperature and compared with the calculated value. The deviation should not be greater than 3%. 8 Power frequency withstand voltage test and induction withstand voltage test of primary winding 8.1 Power frequency withstand voltage test of primary winding
8.1.1 The distance between the test product and the grounding body or adjacent objects should 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 should be less than 80%. 8.1.2 See Figure 2 for the test circuit.
Test transformer; CJ, C2—capacitor voltage divider: T,—test transformer: R protective resistor: V——peak voltage meter. Figure 2
8.1.3 After confirming that the equipment circuit and power supply waveform are correct, apply voltage to the test product. When pressurizing, the voltage should be increased slowly from the mechanical 0 position, and the instrument voltage value should be observed: when it rises to 75% of the test voltage, the voltage should be increased to the test value of the short-time power frequency withstand voltage at a rate of 2% of the test voltage per second and maintained for 1 minute or the specified time, and then the power supply should be cut off after it drops below 30% of the specified test voltage. 8.2 Induction withstand voltage test
8.2.1 The frequency of the test power supply should not be lower than the frequency that causes the magnetic flux saturation in the core, and the generator set should be used as the power supply to supply the voltage transformer test product excitation. Other methods can also be used, but the waveform must meet the requirements. The test voltage should be measured from the high-voltage side during the test. 8.2.2 The test voltage is applied between the winding outlet terminals. The metal clamps, metal base or box shell, iron core, one outlet terminal of each secondary winding and the grounding terminal of the primary winding should be connected together to ground. The applied voltage starts from 0 and increases after it reaches the specified test voltage for the corresponding time, and then drops below 30% of the specified test voltage before the power supply is cut off.
The grounding wire must be in good contact, and the grounding terminal of the primary end of the transformer must be firmly grounded to prevent high potential from being generated due to poor contact, which may endanger the safety of people and instruments.
JB/T53572002
8.2.3 If there is no abnormal phenomenon during the test, the test is qualified. 8.2.4 Other requirements shall be in accordance with the provisions of GB1207--1997. 9 Power frequency withstand voltage test between primary and secondary winding segments and secondary winding 9.1 See Figure 3 for the test circuit.
T Test transformer; A
-Protection resistor:
Ammeter: R-
V, V2-Voltmeter; T,--.-Test transformer: Ci, C2-Capacitor voltage divider. Figure 3
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 before the power is cut off. Voltage transformers with multiple secondary windings should be tested in sequence. 9.3 If there is no breakdown, the test is qualified. 10 Partial discharge measurement
Partial discharge measurement shall be carried out in accordance with the relevant provisions of GB1207-1997. 11
Excitation characteristic measurement
11.1 Test circuit
The test circuit is shown in Figure 4 or Figure 5.
11.2 Test method
The test power supply should be a rated frequency of 50Hz, and the power supply waveform should be an actual sine wave. During the test, the end outlet terminal of the transformer primary winding should be reliably grounded, and the other windings should be open-circuited. The loss value and excitation current value are measured on the transformer secondary winding. The specific measurement points shall be in accordance with the provisions of 4.10.9 in GB1207-1997. When the voltage is measured simultaneously with the average voltage meter and the RMS voltage meter, if the measured voltage values are opposite or the difference is not greater than 2%, the measured loss value does not need to be corrected, and the average voltage meter reading shall prevail. When the average voltage meter reading shows the specified test voltage, read the excitation current value and loss value from the ammeter and wattmeter respectively. If the voltage values read simultaneously from the average voltage meter and the RMS voltage meter differ by more than 2%, correction is required. ?
TV——Autovoltage regulator: V RMS AC voltage meter: W—Low power factor power meter:
AC ammeter: V.
Average AC voltage meter: T, a
Test transformer.
JB/T5357~2002
—Voltage regulator: V——RMS AC voltmeter: W—Low power factor power meter: A—AC ammeter
Average value AC voltmeter; TA-
Current transformer; T-Test transformer.
There are two methods to correct the voltage waveform:
One method is to apply the voltage to the specified value based on the average value voltmeter. Read the current value and loss value. Then, based on the RMS voltmeter, apply the voltage to the specified value and read the current value. Finally, take the average value of the two measured current values as the corrected current value, and the loss value read based on the average value voltmeter is the corrected loss value. Another correction method is to take the readings on the average value voltmeter and the RMS voltmeter, and calculate the corrected loss value. The calculation formula is as follows (for the core using cold-rolled silicon steel sheets): Po
Wherein:
1+(U'/U)2
P. The loss value read based on the average voltmeter reading, the unit is W: U'
-The voltage value read from the root mean square voltmeter based on the average voltmeter reading, the unit is V: U.-Rated voltage root mean square value, the unit is V. Of the above two correction methods, the first correction is more convenient and therefore more commonly used. The difference between the current measurement values of routine tests and type tests should not be greater than 30%. 12 Dielectric loss factor (tan6) measurement
: 12.1 Standard environmental conditions
Relative humidity is not more than 60%:
The test temperature is 10℃～30℃.
12.2 Test method
12.2.1 Ungrounded voltage transformer
The test voltage is applied to the short-circuited primary winding terminal, and the secondary winding is short-circuited and pressed to the metal base or box shell on the measuring bridge for grounding.
The test circuit is shown in Figure 6.
12.2.2 Grounded voltage transformer
12.2.2.1 Core-grounded transformer
During the test, the end of the primary winding is grounded, and the test voltage is applied to the head end of the primary winding. Any outgoing terminal in the secondary winding is connected and connected to the measuring bridge, and the oil tank is grounded.
JB/T5357-2002
The test circuit is shown in Figures 7 and 8.
Regulator: V-
Peak voltage meter; T-
Test transformer: C,
Regulator:
Test transformer: H bridge:
Standard capacitor: CI, C2
Peak voltage meter: T-
Test transformer: C
Regulator: V
Capacitor voltage divider.
Test transformer: H-bridge:
Standard capacitor: CI, C2
Peak voltage meter: T
Test transformer; C
Capacitor voltage divider.
Test transformer: H
Standard capacitor; CJ, C2
Bridge:
Capacitor voltage divider.
12.2.2.2 Transformer with ungrounded core
During the test, the transformer is insulated from the ground, voltage is applied to the first end of the secondary winding, and the end of the secondary winding is grounded. Any outgoing terminal in the secondary winding is connected to the base through the ear, and then connected to the measuring bridge. At this time, the measured tan6 value represents the dielectric loss factor (tan) between the primary winding and the secondary winding, the insulating bracket and the outer porcelain sleeve of the transformer, so it is usually called the overall dielectric loss factor (tan5) of the transformer, see Figure 9. Its test method is also called the end shielding method. If any outgoing terminal in the secondary winding is connected and grounded, and then the base is connected to the measuring bridge, the dielectric loss factor (tan6) of the insulating bracket in the transformer is measured, see Figure 10. Its test method is also called the bracket dielectric loss factor measurement method. The test circuit is shown in Figures 9 and 10.
For electromagnetic voltage transformers with capacitive structure for primary lead insulation, the end screen should be connected to the bridge, and the remaining secondary windings should be open. 13 Error measurement
Error measurement shall be carried out in accordance with the provisions of JG314-1994. 6
Voltage regulator: V-
Bee value voltmeter: T-
Test transformer: C
Test transformer: H
-Standard capacitor: CI, C
Bridge:
Capacitor voltage divider.
TV——Voltage regulator: V-—Peak voltage meter: T—Test transformer; H—Bridge: Test transformer; C
Attention should be paid when measuring error:
Standard capacitor: CI, C2-
-Capacitor voltage divider.
JB/T5357-2002
To prevent the influence of wire voltage drop on the measurement result, it is necessary to ensure that the potential measurement point is on the secondary terminal of the tested transformer. a)
The sum of the resistances of the two leads connected to the load shall not be greater than 1% of the active resistance of the corresponding rated load. b)
14 Insulating oil performance test
The insulating oil performance test shall be carried out in accordance with relevant standards such as GB/T507-1986, GB/T5654-1985, GB/T7252-2001 and GB/T7600-1987.
The performance indicators of insulating oil are shown in Table 2.
The maximum voltage of the equipment
363~550
Temperature rise test
The breakdown voltage shall not be less than
tan (90℃)
and not greater than%
The test shall be carried out in accordance with the provisions of 4.5, 4.10.1 and 6.5.1 of GB1207-1997. 15.1
The test circuit is shown in Figure 11.
Water content is not more than
Hydrogen content is not more than
15.3 Environmental requirements: There should be no factors that affect the ambient temperature around the test site, such as radiation, heat source, airflow, etc. The ambient temperature should be measured using 2 or 3 thermometers, 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 piece; the height is approximately the middle of the test piece height. The ambient temperature is based on the average value of several thermometers. 15.4 To measure the core surface temperature, an alcohol thermometer or other thermometer that is not affected by the magnetic field (such as a thermocouple or resistance thermometer) can be used, and the temperature measuring end should be in close contact with the measured point. JB/T5357-2002
—Voltmeter; A——Amperemeter; R—Load to be connected at 1.2 times the rated primary voltage TV——Voltage regulator: TBooster: V-
—Load to be connected at 1.5 times or 1.9 times the rated primary voltage: R—Residual winding load: T~aTest product: S-
When measuring the top oil temperature, the temperature measuring end of the thermometer should be immersed 50mm~100mm below the oil surface (if there is a thermometer seat, the seat should be filled with oil), 15.5 The average temperature of the winding should be measured by the resistance method, and the same circuit and instrument should be used to measure the cold and hot resistances. 15.6 The method of measuring the average temperature of the winding by the resistance method: After the temperature rise test is completed and the power is cut off, immediately measure the DC resistance of the winding. The first reading should be measured within 1 to 2 minutes after the power outage, and then a resistance value should be measured at equal intervals (30s to 60s) within 8 to 10 minutes, and recorded as Ri, R2, R3, and Rr in sequence. After that, a reference value Rg should be measured every 5 to 10 minutes. At the same time, record each measurement time, which are t, t2, t3, and t. Take the moment of power cut off as o=0. On the logarithmic coordinate paper, draw the corresponding points of (R1-R), (R2-R), (RgR)...(RR) and t2, t3, and t4, and connect them with a straight line. The intersection of the line and the R axis is the (R-R) value at t=0. From this, the resistance R value at the moment of power cut off can be obtained, as shown in Figure 12. R
The average temperature rise of the winding △9 is calculated as follows:
【Linear coordinates】
Ro(235+8.)-(235+82)
Where:
Ro——Hot resistance value of the winding at the moment of power failure, unit is Q; Re
—Cold resistance value when the temperature is 9, unit is 2:Cold temperature of the winding (ambient temperature when cold), unit is ℃:92
The ambient temperature for determining the temperature rise in the later stage of the temperature rise test, unit is ℃:-Average temperature rise of the winding, unit is K:
The inverse of the temperature coefficient of the steel conductor.
The least square method can also be used for data processing. 16 Short-circuit withstand capacity test
Can be carried out according to the provisions of 4.7 and 4.10.2 of GB1207-1997.5 The average temperature of the winding should be measured by the resistance method, and the same circuit and instrument should be used to measure the cold and hot resistances. 15.6 The method of measuring the average temperature of the winding by the resistance method: After the temperature rise test is completed and the power is cut off, the DC resistance of the winding should be measured immediately. The first reading should be measured within 1min to 2min after the power is cut off, and then a resistance value should be measured at equal intervals (30s to 60s) within 8min to 10min, and recorded as Ri, R2, R3, and Rr in sequence. After that, a reference value Rg should be measured every 5min to 10min. At the same time, record each measurement time, which is t, t2, t3, and t. Take the moment of power cut off as o=0. On the logarithmic coordinate paper, draw the corresponding points of (R1-R), (R2-R), (RgR)...(RR) and, t2, 3, and t, and connect them with a straight line. The intersection with the R axis is the (R-R) value at t=0. From this, the resistance R value at the moment of power cut off can be obtained, as shown in Figure 12. R
The average temperature rise of the winding △9 is calculated as follows:
【Linear coordinates】
Ro(235+8.)-(235+82)
Where:
Ro——Hot resistance value of the winding at the moment of power failure, unit is Q; Re
—Cold resistance value when the temperature is 9, unit is 2:Cold temperature of the winding (ambient temperature when cold), unit is ℃:92
The ambient temperature for determining the temperature rise in the later stage of the temperature rise test, unit is ℃:-Average temperature rise of the winding, unit is K:
The inverse of the temperature coefficient of the steel conductor.
The least square method can also be used for data processing. 16 Short-circuit withstand capacity test
Can be carried out according to the provisions of 4.7 and 4.10.2 of GB1207-1997.5 The average temperature of the winding should be measured by the resistance method, and the same circuit and instrument should be used to measure the cold and hot resistances. 15.6 The method of measuring the average temperature of the winding by the resistance method: After the temperature rise test is completed and the power is cut off, the DC resistance of the winding should be measured immediately. The first reading should be measured within 1min to 2min after the power is cut off, and then a resistance value should be measured at equal intervals (30s to 60s) within 8min to 10min, and recorded as Ri, R2, R3, and Rr in sequence. After that, a reference value Rg should be measured every 5min to 10min. At the same time, record each measurement time, which is t, t2, t3, and t. Take the moment of power cut off as o=0. On the logarithmic coordinate paper, draw the corresponding points of (R1-R), (R2-R), (RgR)...(RR) and, t2, 3, and t, and connect them with a straight line. The intersection with the R axis is the (R-R) value at t=0. From this, the resistance R value at the moment of power cut off can be obtained, as shown in Figure 12. R
The average temperature rise of the winding △9 is calculated as follows:
【Linear coordinates】
Ro(235+8.)-(235+82)
Where:
Ro——Hot resistance value of the winding at the moment of power failure, unit is Q; Re
—Cold resistance value when the temperature is 9, unit is 2:Cold temperature of the winding (ambient temperature when cold), unit is ℃:92
The ambient temperature for determining the temperature rise in the later stage of the temperature rise test, unit is ℃:-Average temperature rise of the winding, unit is K:
The inverse of the temperature coefficient of the steel conductor.
The least square method can also be used for data processing. 16 Short-circuit withstand capacity test
Can be carried out according to the provisions of 4.7 and 4.10.2 of GB1207-1997.
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