Some standard content:
ICS31.060.70
Machinery Industry Standard of the People's Republic of China
JB/T7111—1993
High-voltage shunt capacitor installations
High-voltage shunt capacitor installations1993-10-08 Issued
Ministry of Machinery Industry of the People's Republic of China
Implementation on 1994-01-01
Machinery Industry Standard of the People's Republic of China
High-voltage shunt capacitor installationsSubject content and scope of application
JB/T7111—1993
This standard specifies the scope of application, terminology, product classification, technical requirements, test methods, inspection rules, marking, packaging, storage and transportation of high-voltage shunt capacitor installations.
This standard applies to parallel capacitor devices (hereinafter referred to as "devices") connected in parallel in three-phase AC power systems with a frequency of 50Hz or 60Hz and a rated voltage of 1kV or above, used to improve power factor, adjust network voltage, and reduce line losses. 2
Cited standards
6High voltage test technology
GB311.2~311.6
GB1985
GB2681
GB2900.12
GB2900.15
GB2900.16
GB3906
GB4208
GB7675
GB11032
JB3840
JB5346
3Terms
AC high voltage disconnector and earthing switch
Conductor in electrical complete sets Wire color
Electrical terms Lightning arrester
Electrical terms Transformer, mutual inductor, voltage regulator, reactor Electrical terms Power capacitor
3~35kV AC metal-enclosed switchgear
High voltage shunt capacitor
Classification of enclosure protection level
Opening and closing capacitor bank test of AC high-voltage circuit breaker AC gapless metal oxide arrester
Single-unit protection of shunt capacitor High-voltage fuse Series reactor
Except for those clearly stated in this standard, the remaining terms shall comply with the provisions of GB2900.12, GB2900.15 and GB2900.16.
3.1 Shunt capacitor device
It is mainly composed of capacitor bank, switch, series reactor, etc., and is connected in parallel in the power frequency AC three-phase power system to improve power factor, adjust network voltage and reduce line loss. 3.2 Rated frequency of the device (fN)
The frequency used when designing the device.
3.3 Rated voltage of the device (Un)
The rated voltage of the system to which the device is to be connected. Approved by the Ministry of Machinery Industry on October 8, 1993
Implemented on January 1, 1994
3.4 Rated current of the device (IN)
JB/T7111—1993
The current (RMS value) used when designing the device. Its value is the rated current of the capacitor bank in the device. Note: For multi-phase capacitor banks that have been connected internally, the rated current of the capacitor bank refers to the line current. 3.5 Rated capacitance of the device (CN)
The capacitance value used when designing the device, its value is the rated capacitance of the capacitor bank in the device. 3.6 Rated capacity of the device (QN)
The capacity value used when designing the device, its value is the rated capacity of the capacitor bank in the device. (Single) capacitor
An assembly consisting of one or more capacitor elements assembled in a single housing and having lead terminals. 3.8 Capacitor bank
A group of capacitors electrically connected together. 3.9 Rated voltage of capacitor bank (U.)
The voltage used when designing the capacitor bank. Note: For multi-phase capacitor banks with internal connections, U. refers to the line voltage. 3.10
Main circuit
The circuit used to complete the main function.
3.11 Auxiliary circuit
The circuit used to complete the auxiliary function.
2 Open triangle voltage protection
Connected to the open triangle composed of the secondary winding of the discharge coil, the protection that can disconnect the power supply when the residual voltage between the terminals of the open triangle exceeds the specified value.
Differential protection
Protection sensitive to the current difference or voltage difference between two parts of the capacitor bank. 3.14
4 Unbalance protection
Protection that is sensitive to unbalanced current or unbalanced voltage between two parts of a capacitor bank. 3.15
5 Overvoltage protection
Protection that disconnects the power supply when the bus voltage exceeds a specified value. 3.16
6 Overcurrent protection
Protection that disconnects the power supply when the current flowing through the device exceeds a specified value. 3.17
Undervoltage protection
Protection that disconnects the power supply when the bus voltage drops below a specified value. 3.18
Rated reactance ratio
The percentage of the rated inductive reactance of the series reactor to the rated capacitive reactance of the parallel capacitor bank. 4 Product classification
4.1 Installation category
It is divided into two categories: indoor and outdoor.
JB/T7111—1993
Note: According to whether the capacitor bank in the device is installed indoors or outdoors, 4.2 Switching mode
is divided into manual switching and automatic switching. 4.3 Ambient air temperature category
The ambient air temperature range of the installation and operation area is -40℃~+45℃. Within this temperature range, it is divided into several temperature categories according to the ambient air temperature range that the device can adapt to. Each temperature category is represented by a lower limit temperature value and an upper limit temperature value separated by a slash. The lower limit temperature is the lowest ambient air temperature at which the device can be put into operation, and its value is selected from +5℃, -5℃, -25℃, and -40℃. The upper limit temperature is the highest ambient air temperature in which the device can operate continuously, and its value is selected from 40℃ and 45℃. Any combination of the lower limit temperature and the upper limit temperature can be selected as the temperature category of the device, such as -25/40 and -5/45. During the operation of the device, the air temperature measured at the midpoint of the line connecting the hottest points of the shells of two capacitors in the hottest area of the capacitor bank shall not exceed the upper limit temperature plus 5°C.
4.4 Rated voltage of the device
The rated voltage shall be selected from the following values: 3, 6, 10, 35, 63 kV.
4.5 Rated capacity of the device
The rated capacity is recommended to be selected from the following values: 300, 600, 900, 1200, 1500, 1800, 2400, 3000, 3600, 4200, 4800, 5000, 6000, 7200, 8000, 9000, 10000, 12000, 14400, 16800, 20000, 25000, 30000, 40000, 60000 kvar. 4.6 Rated reactance of the device
The rated reactance should be selected within the following ranges: 0.1%~1%, 4.5%~6%, 12%~13%.
Note: Devices with other rated values can be manufactured according to the needs of the purchaser. 5 Technical requirements
5.1 Usage requirements
5.1.1 Altitude
The altitude of the installation and operation area should not exceed 1000m. Note: The requirements for devices used in areas with sea level higher than 1000m shall be determined by negotiation between the manufacturer and the purchaser. 5.1.2 Ambient air temperature
The ambient air temperature of the installation and operation area shall be consistent with the temperature category of the device. 5.1.3 Installation site
The installation site should be free of severe mechanical vibration: there should be no harmful gases and steam: there should be no conductive or explosive dust. 5.1.4 Residual voltage when put into operation
When the device is about to be put into operation, the residual voltage between the terminals of the capacitor bank shall not exceed the value specified in Article 5.3.3. 5.1.5 Overload
5.1.5.1 Steady-state overvoltage
The continuous operating voltage of the device is 1.00UN, and it can operate for a corresponding time under the steady-state overvoltage specified in Table 1. 3
Power frequency overvoltage
5.1.5.2 Steady-state overcurrent
JB/T7111—1993
Maximum duration
30min in every 24h
Steady-state overvoltage
refers to the maximum value of long-term overvoltage not exceeding 1.10Un. Adjustment and fluctuation of system voltage
Voltage rise when light load
The device should be able to operate under the RMS value not exceeding 1.30 times the current generated by the capacitor bank of the device when it is continuously operated at rated frequency, rated sinusoidal voltage and no transient state. Since the actual capacitor may reach 1.10CN, this overcurrent may reach about 1.43IN. This current is the result of the combined effect of the harmonic voltage on the capacitor bank and the power frequency overvoltage up to 1.10U. 5.1.5.3 Maximum allowable capacity
When operating under overvoltage and overcurrent within the limits specified in Articles 5.1.5.1 and 5.1.5.2, the total capacity of the device shall not exceed 1.35QN. 5.1.5.4 Power frequency plus harmonic overvoltage
The overvoltage of power frequency plus harmonics during the operation of the device shall not cause the overcurrent to exceed the value specified in Article 5.1.5.2. If the device is operated for a long time at no more than 1.10Un, the voltage peak including all harmonic components shall not exceed 1.2V2UN. Note: When the device needs to be installed in an environment that does not meet the provisions of this article, the purchaser should negotiate with the manufacturer. 5.2 Structural and conductor requirements
5.2.1 Anti-corrosion layer
The exposed surface of the metal parts of the device shall have a reliable anti-corrosion layer and shall meet the requirements of the relevant technical documents. 5.2.2 Busbars and connecting wires
5.2.2.1 Main circuit busbars and connecting wires
a. The long-term allowable current of the main circuit busbar shall not be less than 1.5In; the long-term allowable current of the connecting wire from a single capacitor to the busbar or fuse shall not be less than 1.5 times the rated current of a single capacitor; the remaining connecting wires shall be selected according to the rated working current or mechanical strength of the corresponding circuit: the busbar connection shall be firm, non-deformed, good in contact, and the configuration shall be neat and beautiful; b.
The material, connection and layout of the busbar shall be able to meet the mechanical strength requirements of the device under normal operation and accident conditions; the color of the busbar and connecting wire shall comply with the provisions of GB2681: d.
The mechanical strength and creepage distance of the busbar support insulator shall be able to meet the requirements of the corresponding use conditions. Auxiliary circuit connecting wire
The cross section of the connecting wire shall comply with the relevant standards: the connection of the connecting wire shall be firm and should not swing freely, and the wiring shall be neat and beautiful; b.
The rated voltage of the connecting wire shall not be lower than the rated working voltage of the corresponding circuit. 5.2.3 Electrical clearance and creepage distance
The electrical clearance and creepage distance of each electrical equipment in the device shall comply with the provisions of relevant standards. The minimum electrical clearance between live parts and between live parts and grounding bodies of indoor devices shall not be less than the values listed in Table 2. The electrical clearance of outdoor devices shall be determined by negotiation between the manufacturer and the purchaser. Relevant positions
Between bare conductors of different phases
Live bare conductor to grounding frame
Live bare conductor to plate-shaped fence
Live bare conductor to mesh door and mesh fence
5.2.4 Protection level
JB/T7111—1993
Minimum electrical clearance for indoor installations
Rated voltage of power system
The protection level of the enclosure of cabinet-type equipment shall be selected according to Table 3. 6
Table 3 Protection level
Auxiliary circuit
Below 500V
Block solids with a diameter greater than 12mm, fingers or similar objects with a length not exceeding 80mmBlock tools, conductors, etc. with a diameter or thickness greater than 2.5mm and other objects with a diameter greater than 2.5mmBlock wires, belts, or other objects with a diameter greater than 1.0mm with a diameter or thickness greater than 1.0mmDustproof (refers to preventing a large amount of dust from entering that affects the safe operation of the equipment. However, it cannot completely prevent dust from entering)5.3 Selection of main circuit and auxiliary circuit equipment
The main circuit and auxiliary circuit equipment include high-voltage disconnectors, high-voltage circuit breakers, series reactors, discharge devices, metal oxide arresters, capacitor banks, grounding switches, etc.
The technical performance of each device should be able to meet the requirements of device performance and safe operation. 5.3.1. The rated current of the selected high-voltage disconnectors and high-voltage circuit breakers shall not be less than 1.5IN, and high-voltage circuit breakers without heavy breakdown shall be selected. For high-voltage circuit breakers required to cut off short-circuit faults, their rated breaking current shall be greater than the short-circuit current of the system at the installation location. High-voltage disconnectors and high-voltage circuit breakers shall be flexible in operation, without excessive operating force or stuck phenomenon, and those assembled into high-voltage switch cabinets shall comply with the provisions of GB3906. 5.3.2 Series Reactor
The series reactor is connected in series in the capacitor circuit to suppress the closing current and harmonics. The selection principle is as follows: If it is only used to suppress the closing inrush current, a reactor with a rated inductance of (0.1%~1%)Xc per phase (Xc is the rated capacitive reactance of each phase of the capacitor bank, a.
The same below) should be selected:
b. If it is used to suppress harmonics of the fifth order or above, a reactor with a rated inductance of (4.5%~6%)Xc per phase should be selected; c. If it is used to suppress harmonics of the third order or above, a reactor with a rated inductance of (12%~13%)Xc per phase should be selected: The series reactor should comply with the provisions of JB5346 and other relevant standards. 5.3.3 Discharge Devicebzxz.net
The discharge device should use a discharge coil dedicated to the capacitor bank. The rated voltage of the discharge device shall not be lower than the rated voltage of the capacitor bank, and the discharge performance shall be able to meet the requirement that the residual voltage on the capacitor bank is reduced from the rated voltage peak to 50V or lower within 5s after the power supply is disconnected. The discharge device shall comply with the technical conditions agreed upon by the manufacturer and the purchaser. Note:
If the discharge device of a single capacitor can meet the above requirements, no additional discharge device may be installed. 5
Metal oxide surge arrester
JB/T7111—1993
When it is necessary to limit the operating overvoltage caused by switching capacitor banks, metal oxide surge arresters should be selected. When selecting metal oxide surge arresters, the connection method of the surge arrester, the possible overvoltage multiples and the capacity of the capacitor bank should be considered. The metal oxide surge arrester can be placed in the high-voltage switch cabinet or near the capacitor bank. The manufacturer and the purchaser shall negotiate and determine that the metal oxide surge arrester shall comply with the relevant provisions of GB11032. 5.3.5 Capacitor Bank
Capacitor banks are generally composed of a single capacitor, busbar, etc., and external fuses can be installed. A single capacitor can be placed on a rack or in a cabinet. The selection of the rated voltage and rated capacity of a single capacitor should be determined according to the voltage and capacity of each phase of the capacitor bank and the number of capacitors in series and parallel in each phase. The design of the capacitor rack should take into account the convenience of maintenance and replacement of equipment. A mesh fence is generally set between the rack and the maintenance channel. If there is an external fuse, a single protective high-voltage fuse should be selected. One end of the fuse is fixed on the busbar and the other end is connected to the capacitor terminal. The fuse should be installed on the channel side, and the installation position and angle of the fuse should comply with the manufacturer's regulations. The main wiring method of the capacitor bank should be single star or double star. The capacitor of each phase should be connected in parallel first and then in series. The single capacitor and the busbar should be connected with a soft conductor. There should be a position for connecting the grounding clamp on the center point side and the power supply side of the capacitor bank busbar. The capacitor bank can also be composed of collective parallel capacitors. The single capacitor in the capacitor bank shall comply with the provisions of GB3983.2; the external fuse shall comply with the provisions of JB3840 and other relevant standards; the collective parallel capacitor shall comply with the provisions of the corresponding standards. 5.3.6 Earthing switch
The device should be equipped with an earthing switch.
The earthing switch shall comply with the relevant provisions of GB1985. 5.4 Selection of protection and control mode
5.4.1 Selection of protection mode
The protection package is based on the protection of the capacitor bank and the protection of the device. The protection mode is negotiated and set by the purchaser and the manufacturer. 5.4.1.1 Protection of capacitor bank
The protection of the capacitor bank includes: internal fuse protection and external fuse protection: relay protection, etc. The internal fuse and external fuse protection are the first protection for the internal fault of the capacitor, and the relay protection is the second protection. Relay protection includes: open triangle voltage protection: voltage differential protection and bridge current differential protection: neutral point unbalanced voltage or neutral line unbalanced current protection, etc.
5.4.1.2 Protection of the device
The protection of the device includes: overcurrent protection; overvoltage protection; undervoltage protection; harmonic protection, etc. Note: Other types of protection can be set as needed. 5.4.2 Selection of control mode
According to the role of the device in the power grid, equipment conditions and operating experience, the purchaser and the manufacturer shall negotiate to adopt one of the following two switching methods:
a. Automatic switching;
b. Manual switching.
The automatic switching device automatically controls the switching on and off of capacitors. The control methods can be as follows: 6
JB/T7111—1993
Automatically switch a single capacitor bank according to voltage, reactive power or time: a.
b.The grouped capacitor banks are automatically switched according to the combination of voltage, reactive power and time. The automatic switching device should have a manual switching function. The wiring of the automatic switching device should have a locking circuit to prevent the device from being mistakenly set when the protection trips, and an operation release control switch should be set. It is strictly forbidden to set an automatic reclosing switch in the control circuit of the device. 5.5 Performance requirements
5.5.1 Capacitance deviation
The difference between the actual capacitance of the device and its rated capacitance should be within the range of 0-10% of the rated capacitance, and the ratio of the maximum to minimum capacitance of each series section should not exceed 1.03.
The ratio of the maximum to minimum capacitance between any two line terminals of the device should not exceed 1.06. 5.5.2 Insulation level
The main circuit of the device between phases, between phases and ground, and between the auxiliary circuit and ground should be able to withstand the withstand voltage specified in Table 4. The power frequency withstand voltage is applied for 1 minute.
Table 4 Insulation level
Rated voltage of device
5.5.3 Temperature rise
Power frequency withstand voltage
Root mean square value
Lightning impulse withstand voltage
(1.2~5)/50μs, peak value
Auxiliary circuit
Power frequency withstand voltage
Root mean square value
The temperature rise of the connection between the busbars of the device and each connection in the main circuit shall not exceed 50℃. The temperature rise of each electrical equipment shall not exceed its own regulations.
5.5.4 Inrush current limiting capability
The device shall be able to limit the inrush current generated at the moment the capacitor bank is put into operation to less than 20 times the rated current of the capacitor bank. Test method
6.1 Test conditions
All tests and measurements of the device, unless otherwise specified, shall be carried out under the following conditions: The ambient air temperature is 5℃~35℃. If correction is required, the value at 20℃ shall prevail. a. During the test, the temperature of the device shall be consistent with the ambient air temperature. After the device is placed in a constant ambient air temperature for an appropriate period of time without power, the temperature of the device is considered to be consistent with the ambient air temperature. The ambient air temperature during the test shall be recorded. b. The frequency of the AC voltage used in the test and measurement shall be (50±1) Hz, and its waveform shall be approximately sinusoidal (that is, the two half-waves are basically the same, and the ratio of their peak value to the root mean square value is within the limit of √2±0.07, and the root mean square value of the harmonics is not greater than 5% of the root mean square value of the fundamental wave).
6.2 Appearance inspection
JB/T 7111—1993
Inspect by visual inspection and measuring tools according to the requirements of 5.2.1~5.2.3. 6.3 Electrical Inspection
Electrical inspection mainly checks whether the main circuit and auxiliary circuit equipment of the device have certificates of conformity, and checks whether their main technical conditions meet the requirements of the electrical performance of the device.
6.4 Capacitance Inspection
The capacitance of the device can be tested by actual capacitance measurement or by calculation based on the actual capacitance of each single capacitor in the device.
The capacitance should meet the requirements of Article 5.5.1.
6.5 Withstand Voltage Test
The withstand voltage test of the device is generally carried out in accordance with the relevant provisions of GB311.2~311.6. Before the test, the connecting wires on the terminals of the series reactor, discharge, coil, metal oxide arrester, and capacitor bank in the device should be disconnected, and they should not be connected during the test. However, these devices should be subject to acceptance tests as required. When the metal oxide arrester is subject to acceptance test, the withstand voltage test shall not be carried out.
6.5.1 Power frequency withstand voltage test
The power frequency withstand voltage test is carried out between the phases of the device, between the phase and the ground, and between the auxiliary circuit and the ground. The test voltage is selected from Table 4. During the test, the test voltage should start from half of the rated voltage of the device or lower, and evenly increase to the test voltage value within 2s~10s, and maintain the specified time at this voltage. No flashover or breakdown should occur during the test. 6.5.2 Lightning impulse withstand voltage test
The lightning impulse withstand voltage test is only carried out on cabinet-type devices intended to be installed outdoors. The voltage is applied between the phases of the device and the ground. The test voltage and waveform are selected from Table 4.
During the test, 15 positive polarity impulses are applied first, followed by 15 negative polarity impulses. After changing the polarity, several low-amplitude impulses are allowed before applying the negative polarity impulse.
If no more than two flashovers occur in each polarity and no breakdown occurs, the device is considered to have passed the test. 6.6 Temperature rise test
During the temperature rise test, a voltage not less than U shall be applied to the device, and the capacity of the device shall be equal to 1.35QN during the entire test. The device shall be placed in the same way as in normal use. During the test, there shall be enough time for the temperature rise to stabilize. The temperature of each specified part shall be measured every 1h~2h with a thermometer, thermocouple or other thermometer. When the temperature change does not exceed 1℃ for 4 consecutive measurements within 6h, the temperature is considered to be stable. For the capacitor bank, the cooling air temperature between the two single capacitors in the hottest area shall also be measured. During the test, the ambient air temperature of the device shall be measured. This measurement shall be carried out with no less than three mercury thermometers or thermocouples calibrated by standard thermometers. The thermometers or thermocouples shall be evenly arranged about 1m away from the device, and the placement height shall be the average height of each current-carrying part of the device. The arithmetic mean of the temperature results of the last two measurements shall be the ambient air temperature of the device. In order to avoid errors caused by rapid changes in temperature, the thermometer or thermocouple should be placed in a container filled with oil so that the thermal time constant is about 1h.
JB/T7111—1993
Note: If limited by the test conditions, this test can also be carried out at the rated voltage after consultation with the purchaser, and then converted to the temperature rise value under 1.35Qn. 6.7 Protection level inspection
This test is only carried out on cabinet-type devices.
During the test, according to the selected protection level, the corresponding test method specified in GB4208 is carried out. 6.8 Discharge device inspection
This test is only carried out on manually switched devices. During the test, the following method is used on any group of capacitors: a DC voltage of √2 times the rated voltage is applied to the capacitor group, and the power supply is disconnected after 1min, and the time it takes for the voltage to drop to 50V is recorded. Note: For the discharge coil, if there is a type test report proving that its discharge performance can meet the requirements, the test may not be carried out. 6.9 Switching test
The switching test shall be carried out in accordance with the relevant provisions of GB7675. Generally, a three-phase test shall be carried out. A single-phase test may be carried out only when the manufacturer and the purchaser have an agreement.
The number of tests is: not less than 3 times for factory test; not less than 10 times for type test. The switching overvoltage and inrush current value at the time of closing shall be measured during type test, and no measurement may be made during factory test. For devices composed of multiple groups of capacitors, the test shall be carried out for each group, and the inrush current value when the last group of capacitors is put into operation shall be measured during type test.
During the test, the switch shall be able to close normally, the mechanical movement shall be flexible, there shall be no excessive operating force or jamming, and there shall be no heavy breakdown. The mechanical interlock or other accessories connected to it shall not be damaged after withstanding the above number of operations. The inrush current value measured during the type test shall not exceed the specified value.
Test of protection device
When testing the protection device, 1~2 capacitors should be connected or removed in parallel in the main circuit to simulate the internal fault of the capacitor, or an equivalent fault signal should be set in the secondary circuit. The protection device should be able to operate normally within the setting range. The number of tests should be no less than 3 times. 6.11 Automatic control test
This test is only carried out on the automatic switching device. During the test, the device should set the operating state according to the set control mode requirements, and its automatic switching device should be able to operate normally. The number of tests should be no less than 3 times.
7 Inspection rules
The test of the device is divided into: factory test, type test and acceptance test. The test items are shown in Table 5.
7.1 Factory test
The purpose of the factory test is to detect defects in manufacturing. This test is carried out by the manufacturer on each set of devices produced. For bench-type devices, if the test conditions are limited, the factory test may not be carried out at the manufacturer after consultation with the purchaser, but may be assessed during the acceptance test.
7.2 Type test
The purpose of type test is to examine whether the design, size, material and manufacturing of the device meet the requirements of this standard. Type test is carried out when new products are manufactured. In production, when there are changes in materials, processes or product structure, and the changes may affect03.
The ratio of the maximum value to the minimum value of the capacitance between any two line terminals of the device shall not exceed 1.06. 5.5.2 Insulation level
The main circuit phases and phases to ground, and the auxiliary circuit to ground of the device shall be able to withstand the withstand voltage specified in Table 4. The power frequency withstand voltage is applied for 1min.
Table 4 Insulation level
Rated voltage of the device
5.5.3 Temperature rise
Power frequency withstand voltage
Root mean square value
Lightning impulse withstand voltage
(1.2~5)/50μs, peak value
Auxiliary circuit
Power frequency withstand voltage
Root mean square value
The temperature rise of the connection between the busbars of the device and each connection in the main circuit shall not exceed 50℃. The temperature rise of each electrical equipment shall not exceed its own regulations.
5.5.4 Inrush current limiting capability
The device should be able to limit the inrush current generated when the capacitor bank is put into operation to less than 20 times the rated current of the capacitor bank. Test method
6.1 Test conditions
All tests and measurements of the device, unless otherwise specified, should be carried out under the following conditions: The ambient air temperature is 5℃~35℃. If correction is required, the value at 20℃ shall prevail. a.
During the test, the temperature of the device should be consistent with the ambient air temperature. After the device is placed in a constant ambient air temperature for an appropriate period of time without power, the temperature of the device is considered to be consistent with the ambient air temperature. The ambient air temperature during the test should be recorded. b. The frequency of the AC voltage used in the test and measurement should be (50 ± 1) Hz, and its waveform should be approximately sinusoidal (i.e. the two half-waves are basically the same, and the ratio of their peak value to the RMS value is within the limit of √2 ± 0.07, and the RMS value of the harmonics is not greater than 5% of the RMS value of the fundamental wave).
6.2 Appearance inspection
JB/T 7111—1993
Inspect by visual inspection and measuring tools according to the requirements of 5.2.1 to 5.2.3. 6.3 Electrical inspection
Electrical inspection mainly checks whether the main circuit and auxiliary circuit equipment of the device have certificates, and checks whether their main technical conditions meet the requirements of the electrical performance of the device.
6.4 Capacitance inspection
The capacitance of the device can be inspected by the actual capacitance measurement method, or by calculation based on the actual capacitance of each single capacitor in the device.
The capacitance should meet the requirements of 5.5.1.
6.5 Withstand voltage test
The withstand voltage test of the device is generally carried out in accordance with the relevant provisions of GB311.2~311.6. Before the test, the connecting wires on the terminals of the series reactor, discharge, coil, metal oxide arrester, and capacitor bank in the device should be disconnected, and they should not be connected during the test. However, these devices should be subject to acceptance tests in accordance with regulations. When the metal oxide arrester is subject to acceptance tests, the withstand voltage test shall not be carried out.
6.5.1 Power frequency withstand voltage test
The power frequency withstand voltage test is carried out between the phases of the device, between the phase and the ground, and between the auxiliary circuit and the ground. The test voltage is selected from Table 4. During the test, the test voltage should start from half of the rated voltage of the device or lower, and evenly increase to the test voltage value within 2s~10s, and maintain the specified time at this voltage. No flashover or breakdown should occur during the test. 6.5.2 Lightning impulse withstand voltage test
The lightning impulse withstand voltage test is only carried out on cabinet devices intended to be installed outdoors. The voltage is applied between the phase and the ground of the device, and the test voltage and waveform are selected from Table 4.
During the test, 15 positive polarity impulses are applied first, followed by 15 negative polarity impulses. After changing the polarity, several low-amplitude impulses are allowed to be applied before applying the negative polarity impulse.
If no more than two flashovers occur for each polarity and no breakdown occurs, the device is considered to have passed the test. 6.6 Temperature rise test
During the temperature rise test, a voltage not less than U should be applied to the device, and the capacity of the device should be equal to 1.35QN during the entire test process. The device should be placed in the same way as in normal use. During the test, there should be enough time for the temperature rise to stabilize. Use a thermometer, thermocouple or other temperature measuring instrument to measure the temperature of each specified part every 1h~2h. When the temperature change does not exceed 1℃ for 4 consecutive measurements within 6 hours, the temperature is considered to be stable. The cooling air temperature between the two single capacitors in the hottest area of the capacitor bank should also be measured. The ambient air temperature of the device should be measured during the test. This measurement should be carried out with no less than three mercury thermometers or thermocouples calibrated by standard thermometers. The thermometers or thermocouples are evenly arranged at about 1m away from the device, and the placement height should be the average height of each current-carrying part of the device. The arithmetic mean of the temperature results of the last two measurements is the ambient air temperature of the device. In order to avoid errors caused by rapid changes in temperature, the thermometer or thermocouple should be placed in a container filled with oil so that the thermal time constant is about 1h.
JB/T7111—1993
Note: If limited by the test conditions, this test can also be carried out at rated voltage and then converted to the temperature rise value under 1.35Qn after consultation with the purchaser. 6.7 Protection level inspection
This test is only carried out on cabinet-type devices.
During the test, the corresponding test method specified in GB4208 shall be followed according to the selected protection level. 6.8 Discharge device inspection
This test is only carried out on manually switched devices. During the test, the following method shall be used on any group of capacitors: a DC voltage of √2 times the rated voltage shall be applied to the capacitor group, the power supply shall be disconnected after 1 minute, and the time taken for the voltage to drop to 50V shall be recorded. Note: For the discharge coil, if there is a type test report proving that its discharge performance can meet the requirements, the test may not be carried out. 6.9 Switching test
The switching test shall be carried out in accordance with the relevant provisions of GB7675. Generally, a three-phase test shall be carried out. A single-phase test may be carried out only when the manufacturer and the purchaser have an agreement.
The number of tests shall be: no less than 3 times for factory test and no less than 10 times for type test. During the type test, the switching overvoltage and inrush current value at the time of closing shall be measured. The measurement is not required during the factory test. For devices composed of multiple groups of capacitors, the test shall be carried out on each group, and the inrush current value when the last group of capacitors is put into operation shall be measured during the type test.
During the test, the switch shall be able to close normally, the mechanical movement shall be flexible, there shall be no excessive operating force or jamming, and no heavy breakdown shall occur. The mechanical interlock or other accessories connected to it shall not be damaged after the above number of operations. The inrush current value measured during the type test shall not exceed the specified value.
Protection device test
When conducting the protection device test, 1~2 capacitors shall be connected or removed in parallel in the main circuit to simulate the internal fault of the capacitor, or an equivalent fault signal shall be set in the secondary circuit. The protection device shall be able to operate normally within the setting range. The number of tests shall not be less than 3 times. 6.11 Automatic control test
This test is only carried out on the device with automatic switching. During the test, the device should be set to the operating state according to the set control mode requirements, and its automatic switching equipment should be able to operate normally. The number of tests shall not be less than 3 times.
7 Inspection rules
The tests of the device are divided into: factory test, type test and acceptance test. The test items are shown in Table 5.
7.1 Factory test
The purpose of the factory test is to detect defects in manufacturing. This test is carried out by the manufacturer on each set of equipment produced. For bench-type devices, if the test conditions are limited, the factory test may not be carried out at the manufacturer, but during the acceptance test after consultation with the purchaser.
7.2 Type test
The purpose of the type test is to examine whether the design, size, material and manufacturing of the device meet the requirements of this standard. Type tests are carried out when new products are produced. In production, when there are changes in materials, processes or product structures, and their changes may affect 903.
The ratio of the maximum value to the minimum value of the capacitance between any two line terminals of the device shall not exceed 1.06. 5.5.2 Insulation level
The main circuit phases and phases to ground, and the auxiliary circuit to ground of the device shall be able to withstand the withstand voltage specified in Table 4. The power frequency withstand voltage is applied for 1min.
Table 4 Insulation level
Rated voltage of the device
5.5.3 Temperature rise
Power frequency withstand voltage
Root mean square value
Lightning impulse withstand voltage
(1.2~5)/50μs, peak value
Auxiliary circuit
Power frequency withstand voltage
Root mean square value
The temperature rise of the connection between the busbars of the device and each connection in the main circuit shall not exceed 50℃. The temperature rise of each electrical equipment shall not exceed its own regulations.
5.5.4 Inrush current limiting capability
The device should be able to limit the inrush current generated when the capacitor bank is put into operation to less than 20 times the rated current of the capacitor bank. Test method
6.1 Test conditions
All tests and measurements of the device, unless otherwise specified, should be carried out under the following conditions: The ambient air temperature is 5℃~35℃. If correction is required, the value at 20℃ shall prevail. a.
During the test, the temperature of the device should be consistent with the ambient air temperature. After the device is placed in a constant ambient air temperature for an appropriate period of time without power, the temperature of the device is considered to be consistent with the ambient air temperature. The ambient air temperature during the test should be recorded. b. The frequency of the AC voltage used in the test and measurement should be (50 ± 1) Hz, and its waveform should be approximately sinusoidal (i.e. the two half-waves are basically the same, and the ratio of their peak value to the RMS value is within the limit of √2 ± 0.07, and the RMS value of the harmonics is not greater than 5% of the RMS value of the fundamental wave).
6.2 Appearance inspection
JB/T 7111—1993
Inspect by visual inspection and measuring tools according to the requirements of 5.2.1 to 5.2.3. 6.3 Electrical inspection
Electrical inspection mainly checks whether the main circuit and auxiliary circuit equipment of the device have certificates, and checks whether their main technical conditions meet the requirements of the electrical performance of the device.
6.4 Capacitance inspection
The capacitance of the device can be inspected by the actual capacitance measurement method, or by calculation based on the actual capacitance of each single capacitor in the device.
The capacitance should meet the requirements of 5.5.1.
6.5 Withstand voltage test
The withstand voltage test of the device is generally carried out in accordance with the relevant provisions of GB311.2~311.6. Before the test, the connecting wires on the terminals of the series reactor, discharge, coil, metal oxide arrester, and capacitor bank in the device should be disconnected, and they should not be connected during the test. However, these devices should be subject to acceptance tests in accordance with regulations. When the metal oxide arrester is subject to acceptance tests, the withstand voltage test shall not be carried out.
6.5.1 Power frequency withstand voltage test
The power frequency withstand voltage test is carried out between the phases of the device, between the phase and the ground, and between the auxiliary circuit and the ground. The test voltage is selected from Table 4. During the test, the test voltage should start from half of the rated voltage of the device or lower, and evenly increase to the test voltage value within 2s~10s, and maintain the specified time at this voltage. No flashover or breakdown should occur during the test. 6.5.2 Lightning impulse withstand voltage test
The lightning impulse withstand voltage test is only carried out on cabinet devices intended to be installed outdoors. The voltage is applied between the phase and the ground of the device, and the test voltage and waveform are selected from Table 4.
During the test, 15 positive polarity impulses are applied first, followed by 15 negative polarity impulses. After changing the polarity, several low-amplitude impulses are allowed to be applied before applying the negative polarity impulse.
If no more than two flashovers occur for each polarity and no breakdown occurs, the device is considered to have passed the test. 6.6 Temperature rise test
During the temperature rise test, a voltage not less than U should be applied to the device, and the capacity of the device should be equal to 1.35QN during the entire test process. The device should be placed in the same way as in normal use. During the test, there should be enough time for the temperature rise to stabilize. Use a thermometer, thermocouple or other temperature measuring instrument to measure the temperature of each specified part every 1h~2h. When the temperature change does not exceed 1℃ for 4 consecutive measurements within 6 hours, the temperature is considered to be stable. The cooling air temperature between the two single capacitors in the hottest area of the capacitor bank should also be measured. The ambient air temperature of the device should be measured during the test. This measurement should be carried out with no less than three mercury thermometers or thermocouples calibrated by standard thermometers. The thermometers or thermocouples are evenly arranged at about 1m away from the device, and the placement height should be the average height of each current-carrying part of the device. The arithmetic mean of the temperature results of the last two measurements is the ambient air temperature of the device. In order to avoid errors caused by rapid changes in temperature, the thermometer or thermocouple should be placed in a container filled with oil so that the thermal time constant is about 1h.
JB/T7111—1993
Note: If limited by the test conditions, this test can also be carried out at rated voltage and then converted to the temperature rise value under 1.35Qn after consultation with the purchaser. 6.7 Protection level inspection
This test is only carried out on cabinet-type devices.
During the test, the corresponding test method specified in GB4208 shall be followed according to the selected protection level. 6.8 Discharge device inspection
This test is only carried out on manually switched devices. During the test, the following method shall be used on any group of capacitors: a DC voltage of √2 times the rated voltage shall be applied to the capacitor group, the power supply shall be disconnected after 1 minute, and the time taken for the voltage to drop to 50V shall be recorded. Note: For the discharge coil, if there is a type test report proving that its discharge performance can meet the requirements, the test may not be carried out. 6.9 Switching test
The switching test shall be carried out in accordance with the relevant provisions of GB7675. Generally, a three-phase test shall be carried out. A single-phase test may be carried out only when the manufacturer and the purchaser have an agreement.
The number of tests shall be: no less than 3 times for factory test; no less than 10 times for type test. During the type test, the switching overvoltage and inrush current value at the time of closing shall be measured. No measurement is required during the factory test. For devices composed of multiple groups of capacitors, the test shall be carried out on each group, and the inrush current value when the last group of capacitors is put into operation shall be measured during the type test.
During the test, the switch shall be able to close normally, the mechanical movement shall be flexible, there shall be no excessive operating force or jamming, and no heavy breakdown shall occur. The mechanical interlock or other accessories connected to it shall not be damaged after the above number of operations. The inrush current value measured during the type test shall not exceed the specified value.
Protection device test
When conducting the protection device test, 1~2 capacitors shall be connected or removed in parallel in the main circuit to simulate the internal fault of the capacitor, or an equivalent fault signal shall be set in the secondary circuit. The protection device shall be able to operate normally within the setting range. The number of tests shall not be less than 3 times. 6.11 Automatic control test
This test is only carried out on the device with automatic switching. During the test, the device should be set to the operating state according to the set control mode requirements, and its automatic switching equipment should be able to operate normally. The number of tests shall not be less than 3 times.
7 Inspection rules
The tests of the device are divided into: factory test, type test and acceptance test. The test items are shown in Table 5.
7.1 Factory test
The purpose of the factory test is to detect defects in manufacturing. This test is carried out by the manufacturer on each set of equipment produced. For bench-type devices, if the test conditions are limited, the factory test may not be carried out at the manufacturer, but during the acceptance test after consultation with the purchaser.
7.2 Type test
The purpose of the type test is to examine whether the design, size, material and manufacturing of the device meet the requirements of this standard. Type tests are carried out when new products are produced. In production, when there are changes in materials, processes or product structures, and their changes may affect 94 Inrush current limiting capability
The device should be able to limit the inrush current generated when the capacitor bank is put into operation to less than 20 times the rated current of the capacitor bank. Test method
6.1 Test conditions
All tests and measurements of the device, unless otherwise specified, should be carried out under the following conditions: The ambient air temperature is 5℃~35℃. If correction is required, the value at 20℃ shall prevail. a. During the
test, the temperature of the device should be consistent with the ambient air temperature. After the device is placed in a constant ambient air temperature for a suitable long time without power, it is considered that the temperature of the device is consistent with the ambient air temperature. The ambient air temperature during the test should be recorded. b. The frequency of the AC voltage used in the test and measurement should be (50±1) Hz, and its waveform should be an approximate sine waveform (that is, the two half-waves are basically the same, and the ratio of their peak value to the root mean square value is within the limit of √2±0.07, and the root mean square value of the harmonics is not greater than 5% of the root mean square value of the fundamental wave).
6.2 Appearance inspection
JB/T 7111—1993
Inspect with visual inspection and measuring tools according to the requirements of 5.2.1~5.2.3. 6.3 Electrical inspection
Electrical inspection mainly checks whether the main circuit and auxiliary circuit equipment of the device have certificates of conformity, and checks whether their main technical conditions meet the requirements of the electrical performance of the device.
6.4 Capacitance inspection
The capacitance of the device can be inspected by the actual capacitance measurement method, or by calculation method based on the actual capacitance of each single capacitor in the device.
The capacitance should meet the requirements of 5.5.1.
6.5 Withstand voltage test
The withstand voltage test of the device is generally carried out in accordance with the relevant provisions in GB311.2~311.6. Before the test, the connecting wires on the terminals of the series reactor, discharge, coil, metal oxide arrester, and capacitor bank in the device should be disconnected, and they should not be connected during the test. However, these equipments shall be subject to acceptance tests as specified. During acceptance tests on metal oxide shields, withstand voltage tests shall not be conducted.
6.5.1 Power frequency withstand voltage test
The power frequency withstand voltage test is conducted between phases of the device, between phases and ground, and between auxiliary circuits and ground. The test voltage is selected from Table 4. During the test, the test voltage shall be started from half of the rated voltage of the device or lower, and uniformly increased to the test voltage value within 2s~10s, and maintained at this voltage for the specified time. No flashover or breakdown shall occur during the test. 6.5.2 Lightning impulse withstand voltage test
The lightning impulse withstand voltage test is only conducted on cabinet-type devices intended to be installed outdoors. The voltage is applied between the phases of the device and ground, and the test voltage and waveform are selected from Table 4.
During the test, 15 positive polarity impulses are applied first, followed by 15 negative polarity impulses. After changing the polarity, several low-amplitude impulses are allowed before applying negative polarity impulses.
If no more than two flashovers occur in each polarity and no breakdown occurs, the device is considered to have passed the test. 6.6 Temperature rise test
During the temperature rise test, a voltage not less than U shall be applied to the device, and the capacity of the device shall be equal to 1.35QN during the entire test. The device shall be placed in the same way as in normal use. During the test, there shall be enough time for the temperature rise to stabilize. The temperature of each specified part shall be measured every 1h~2h with a thermometer, thermocouple or other thermometer. When the temperature change does not exceed 1℃ for 4 consecutive measurements within 6h, the temperature is considered to be stable. For the capacitor bank, the cooling air temperature between the two single capacitors in the hottest area shall also be measured. During the test, the ambient air temperature of the device shall be measured. This measurement shall be carried out with no less than three mercury thermometers or thermocouples calibrated by standard thermometers. The thermometers or thermocouples shall be evenly arranged about 1m away from the device, and the placement height shall be the average height of each current-carrying part of the device. The arithmetic mean of the temperature results of the last two measurements shall be the ambient air temperature of the device. In order to avoid errors caused by rapid changes in temperature, the thermometer or thermocouple should be placed in a container filled with oil so that the thermal time constant is about 1h.
JB/T7111—1993
Note: If limited by the test conditions, this test can also be carried out at the rated voltage after consultation with the purchaser, and then converted to the temperature rise value under 1.35Qn. 6.7 Protection level inspection
This test is only carried out on cabinet-type devices.
During the test, according to the selected protection level, the corresponding test method specified in GB4208 is carried out. 6.8 Discharge device inspection
This test is only carried out on manually switched devices. During the test, the following method is used on any group of capacitors: a DC voltage of √2 times the rated voltage is applied to the capacitor group, and the power supply is disconnected after 1min, and the time it takes for the voltage to drop to 50V is recorded. Note: For the discharge coil, if there is a type test report proving that its discharge performance can meet the requirements, the test may not be carried out. 6.9 Switching test
The switching test shall be carried out in accordance with the relevant provisions of GB7675. Generally, a three-phase test shall be carried out. A single-phase test may be carried out only when the manufacturer and the purchaser have an agreement.
The number of tests is: not less than 3 times for factory test; not less than 10 times for type test. The switching overvoltage and inrush current value at the time of closing shall be measured during type test, and no measurement may be made during factory test. For devices composed of multiple groups of capacitors, the test shall be carried out for each group, and the inrush current value when the last group of capacitors is put into operation shall be measured during type test.
During the test, the switch shall be able to close normally, the mechanical movement shall be flexible, there shall be no excessive operating force or jamming, and there shall be no heavy breakdown. The mechanical interlock or other accessories connected to it shall not be damaged after the above-mentioned number of operations. The inrush current value measured during the type test shall not exceed the specified value.
Test of protection device
When testing the protection device, 1~2 capacitors should be connected or removed in parallel in the main circuit to simulate the internal fault of the capacitor, or an equivalent fault signal should be set in the secondary circuit. The protection device should be able to operate normally within the setting range. The number of tests should be no less than 3 times. 6.11 Automatic control test
This test is only carried out on the automatic switching device. During the test, the device should set the operating state according to the set control mode requirements, and its automatic switching device should be able to operate normally. The number of tests should be no less than 3 times.
7 Inspection rules
The test of the device is divided into: factory test, type test and acceptance test. The test items are shown in Table 5.
7.1 Factory test
The purpose of the factory test is to detect defects in manufacturing. This test is carried out by the manufacturer on each set of devices produced. For bench-type devices, if the test conditions are limited, the factory test may not be carried out at the manufacturer after consultation with the purchaser, but may be assessed during the acceptance test.
7.2 Type test
The purpose of type test is to examine whether the design, size, material and manufacturing of the device meet the requirements of this standard. Type test is carried out when new products are manufactured. In production, when there are changes in materials, processes or product structure, and the changes may affect4 Inrush current limiting capability
The device should be able to limit the inrush current generated when the capacitor bank is put into operation to less than 20 times the rated current of the capacitor bank. Test method
6.1 Test conditions
All tests and measurements of the device, unless otherwise specified, should be carried out under the following conditions: The ambient air temperature is 5℃~35℃. If correction is required, the value at 20℃ shall prevail. a. During the
test, the temperature of the device should be consistent with the ambient air temperature. After the device is placed in a constant ambient air temperature for a suitable long time without power, the temperature of the device is considered to be consistent with the ambient air temperature. The ambient air temperature during the test should be recorded. b. The frequency of the AC voltage used in the test and measurement should be (50±1) Hz, and its waveform should be an approximate sine waveform (that is, the two half-waves are basically the same, and the ratio of their peak value to the root mean square value is within the limit of √2±0.07, and the root mean square value of the harmonics is not greater than 5% of the root mean square value of the fundamental wave).
6.2 Appearance inspection
JB/T 7111—1993
Inspect with visual inspection and measuring tools according to the requirements of 5.2.1~5.2.3. 6.3 Electrical inspection
Electrical inspection mainly checks whether the main circuit and auxiliary circuit equipment of the device have certificates of conformity, and checks whether their main technical conditions meet the requirements of the electrical performance of the device.
6.4 Capacitance inspection
The capacitance of the device can be inspected by the actual capacitance measurement method, or by calculation method based on the actual capacitance of each single capacitor in the device.
The capacitance should meet the requirements of 5.5.1.
6.5 Withstand voltage test
The withstand voltage test of the device is generally carried out in accordance with the relevant provisions in GB311.2~311.6. Before the test, the connecting wires on the terminals of the series reactor, discharge, coil, metal oxide arrester, and capacitor bank in the device should be disconnected, and they should not be connected during the test. However, these equipments shall be subject to acceptance tests as specified. During acceptance tests on metal oxide shields, withstand voltage tests shall not be conducted.
6.5.1 Power frequency withstand voltage test
The power frequency withstand voltage test is conducted between phases of the device, between phases and ground, and between auxiliary circuits and ground. The test voltage is selected from Table 4. During the test, the test voltage shall be started from half of the rated voltage of the device or lower, and uniformly increased to the test voltage value within 2s~10s, and maintained at this voltage for the specified time. No flashover or breakdown shall occur during the test. 6.5.2 Lightning impulse withstand voltage test
The lightning impulse withstand voltage test is only conducted on cabinet-type devices intended to be installed outdoors. The voltage is applied between the phases of the device and ground, and the test voltage and waveform are selected from Table 4.
During the test, 15 positive polarity impulses are applied first, followed by 15 negative polarity impulses. After changing the polarity, several low-amplitude impulses are allowed before applying negative polarity impulses.
If no more than two flashovers occur in each polarity and no breakdown occurs, the device is considered to have passed the test. 6.6 Temperature rise test
During the temperature rise test, a voltage not less than U shall be applied to the device, and the capacity of the device shall be equal to 1.35QN during the entire test. The device shall be placed in the same way as in normal use. During the test, there shall be enough time for the temperature rise to stabilize. The temperature of each specified part shall be measured every 1h~2h with a thermometer, thermocouple or other thermometer. When the temperature change does not exceed 1℃ for 4 consecutive measurements within 6h, the temperature is considered to be stable. For the capacitor bank, the cooling air temperature between the two single capacitors in the hottest area shall also be measured. During the test, the ambient air temperature of the device shall be measured. This measurement shall be carried out with no less than three mercury thermometers or thermocouples calibrated by standard thermometers. The thermometers or thermocouples shall be evenly arranged about 1m away from the device, and the placement height shall be the average height of each current-carrying part of the device. The arithmetic mean of the temperature results of the last two measurements shall be the ambient air temperature of the device. In order to avoid errors caused by rapid changes in temperature, the thermometer or thermocouple should be placed in a container filled with oil so that the thermal time constant is about 1h.
JB/T7111—1993
Note: If limited by the test conditions, this test can also be carried out at the rated voltage after consultation with the purchaser, and then converted to the temperature rise value under 1.35Qn. 6.7 Protection level inspection
This test is only carried out on cabinet-type devices.
During the test, according to the selected protection level, the corresponding test method specified in GB4208 is carried out. 6.8 Discharge device inspection
This test is only carried out on manually switched devices. During the test, the following method is used on any group of capacitors: a DC voltage of √2 times the rated voltage is applied to the capacitor gr
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