CN219142987U - Medium-voltage switchgear condensation test aging device - Google Patents
Medium-voltage switchgear condensation test aging device Download PDFInfo
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- CN219142987U CN219142987U CN202223378442.9U CN202223378442U CN219142987U CN 219142987 U CN219142987 U CN 219142987U CN 202223378442 U CN202223378442 U CN 202223378442U CN 219142987 U CN219142987 U CN 219142987U
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Abstract
The utility model relates to an aging test technology, in particular to a condensation test aging device of medium-voltage switchgear, which is characterized by at least comprising the following components: the environment test box, the test article, the high-pressure environment unit, the condensation environment unit, test support, the test article is placed on test support, form the distance with ground, in the test support is apart from in the environment test box, there is dry wall bushing on the upper left end of environment test box, the high-pressure environment unit is introduced to the test article through dry wall bushing in the environment test box, there is the condensation environment unit right-hand member on environment test box (9), the condensation environment unit makes the environment test box (9) in formation condensation environment. The requirements of GB/T3906-2020 and DL/T593-2016 condensation tests can be met for 3.6-40.5 kV medium-voltage switch equipment.
Description
Technical Field
The utility model relates to an aging test system, in particular to a condensation test aging device for medium-voltage switchgear.
Background
Condensation refers to a physical phenomenon in which moisture in air is precipitated in a liquid form and adheres to a solid surface when the temperature of the air reaches a dew point temperature at a specific humidity. The switch equipment can seriously reduce the external insulation strength of the switch equipment in a condensation state for a long time, so that insulation breakdown is caused, and even a short-circuit accident is induced. The power grid operation data show that condensation is one of important causes for abnormal discharge of medium-voltage switching equipment and power interruption. In order to verify the insulation and corrosion resistance of the switch equipment under the condensation working condition, corresponding test procedures, test methods and judgment standard tests are respectively provided in GB/T3906-2020 and DL/T593-2016.
The condensation test belongs to a typical comprehensive environment test (electric + environment), GB/T3906-2020 prescribes that the voltage drop of a sample side caused by the increase of leakage current in the condensation test is less than or equal to 5%, but the conventional power frequency test power supply is usually single-phase, small in rated working current, large in short circuit impedance and free of taps of a low-voltage winding, so that the short circuit current of a loop in a pollution test under the prescribed test voltage does not meet the requirements of GB/T4585-2004.
Disadvantages of current conventional test devices or systems:
1. at present, no single three/phase aging test system solution for a mature, complete and systematic condensation test meeting the standard requirements is known.
2. In a strict sense, various characteristic parameters (such as voltage drop, maximum short-circuit current, power supply capacity and the like) of the power supply device for the power frequency test do not meet standard requirements.
Disclosure of Invention
The utility model aims to provide a condensation test aging device for medium-voltage switchgear, so that the requirements of GB/T3906-2020 and DL/T593-2016 condensation tests on 3.6-40.5 kV medium-voltage switchgear can be met simultaneously.
The utility model aims to realize the aging device for the condensation test of the medium-voltage switch equipment, which is characterized by at least comprising the following components: the environment test box (9), the test article (8), the high-voltage environment unit, the condensation environment unit and the test support (10), wherein the test article (8) is placed on the test support (10) and forms a distance with the ground, the test support (10) is arranged in the environment test box (9) in the middle, the dry type wall bushing (7) is arranged at the left end on the environment test box (9), the high-voltage environment unit penetrates through the dry type wall bushing (7) to be introduced into the test article (8) in the environment test box (9), the condensation environment unit is arranged at the right end on the environment test box (9), the high-voltage environment unit is connected with a power supply of the test article (8), and a 3.6-40.5 kV medium-voltage switching power supply is provided for the test article (8); the high-pressure environment unit includes: the device comprises a thyristor voltage drop compensation unit (1), a three-phase voltage regulator (2), a single/three-phase aging test power frequency test power supply (3), a high-voltage ammeter (4), a power frequency protection resistor (5) and a capacitive voltage divider (6); 3.6-40.5 kV voltage is input to a three-phase voltage regulator (2) through a thyristor voltage drop compensation unit (1), the output end of the three-phase voltage regulator (2) is connected into a single/three-phase aging test power frequency test power supply (3), the single/three-phase aging test power supply (3) divides the three-phase voltage, the three-phase voltage is respectively led into a three-phase end of a sample (8) in an environmental test box (9) through three dry wall bushings (7) through a capacitive voltage divider (6) through a high-voltage ammeter (4) and a power frequency protection resistor (5) which are connected in series.
The three-phase voltage regulator (2) adopts a column voltage regulator with 600kVA and 10/0-10 kV, and the impedance voltage is 3% -12%; the power frequency test power supply (3) for the single/three-phase aging test is three-phase, has the capacity of 500kVA and the transformation ratio of 4 multiplied by 10/120kV, is used for bearing the unbalanced current effect during single-phase operation, and the low-voltage side of the power supply is composed of 4 groups of 10kV windings which can be connected in series and in parallel.
The high-voltage ammeter (4) is anti-interference, the measuring range is 0-50A, the in-meter electrified optical conversion device transmits the measuring result to the remote measuring and controlling computer through the optical fiber.
The design transformation ratio of the capacitive voltage divider (6) is 1000:1, and the capacitances of the high and low voltage arms are respectively: 2000pF and 2 uf.
The condensation environment unit comprises: the device comprises an RO water treatment unit (12), an electric heating humidifier (13), a hot fog spray head (14), an ultrasonic high-frequency atomization generator (15) and a cold fog horn spray head (16); domestic water is processed into soft water through an RO water treatment unit (12) and is provided for an electric heating humidifier (13), the electric heating humidifier (13) is controlled to provide soft water with required temperature for an ultrasonic high-frequency atomization generator (15), atomization is formed by the ultrasonic high-frequency atomization generator (15), atomized steam liquid is output to an environment test box through a cold fog horn nozzle (16), and the environment test box generates condensation.
The RO water treatment unit (12) stores tap water into a raw water tank, the water in the raw water tank is pressurized by an additional pump and filtered by a multi-medium filter, an active carbon filter, a sodium ion softener and a precision filter, and after the primary reverse osmosis is carried out by a primary high-pressure pump, the water in a pure water tank is added, and then soft water is formed by secondary reverse osmosis; the conductivity of the soft water can be controlled to be less than 5 mu S/cm, and the requirement of a DL/T593-2016 annex M condensation test can be met after the water mixing adjustment.
The environment test box (9) comprises a leakage current measuring meter (11) which is connected between the environment test box (9) and the ground and is used for acquiring leakage current of the environment test box (9).
Advantages and Critical Point of the utility model
1. The single three/phase aging test system for the condensation test of the medium-voltage switch equipment can realize single-phase and three-phase tests, and can simultaneously meet the requirements of GB/T3906-2020 and DL/T593-2016 condensation tests. Saves the investment of the field and the test equipment, and is a mature condensation aging test solution of the medium-voltage switch equipment.
2. The power frequency test power supply for the special single/three-phase aging test is designed. The high-voltage winding has 120kV to the ground voltage, the low-voltage winding is divided into four groups, and the four groups can be connected in series and parallel, so that the requirement of loop short-circuit current in pollution test under standard specified test voltage is solved.
3. The designed test system strictly meets the requirements (such as voltage drop, maximum short-circuit current, climate environment, condensation condition, fog average particle diameter and the like) of the condensation pollution test in GB/T3906-2020, DL/T593-2016 and GB/T4585-2004
4. The system is designed with hot fog and cold fog. The advantages of high hot fog generating efficiency, short time, small cold fog particle size, and the like are taken into consideration.
5. The top of the environmental test box is designed to be a slope top, the gradient is 2 degrees, the top fog is convenient to condense during the condensation test, and slides down along the slope top to the periphery, so that water drops in the middle of the roof are prevented from dripping onto a test sample, and the test sample is prevented from being discharged to invalidate the test.
6. The high-voltage current meter and the leakage current meter both adopt an automatic range switching mode, and the optical fiber transmission scheme with strong anti-interference capability and isolation function can improve the safety of a measuring system.
7. The specific design parameters and the model selection basis of each original component are given in the design, and the method can be used for guiding actual production.
Drawings
The utility model is further described with reference to the following examples and figures of examples:
FIG. 1 is a schematic diagram of a single three/phase aging test system for a condensation test of medium voltage switchgear;
fig. 2 is a three-phase limb voltage regulator impedance characteristic;
FIG. 3 is a single/three phase aging test power supply (phase A);
FIG. 4A is a top view of a mesh test stand;
FIG. 4B is a front view of a mesh test;
FIG. 5 is a thermal spray head;
fig. 6 is an ultrasonic high frequency atomization generator.
In the figure, 1, a thyristor voltage sag compensation unit; 2. three-phase column voltage regulator; 3. a single/three-phase aging test power supply; 4. a high voltage ammeter; 5. a power frequency protection resistor; 6. a capacitive voltage divider; 7. a dry wall bushing; 8. test article (indoor switch cabinet); 9. an environmental test chamber; 10. a test stand; 11. a leakage current meter; 12. an RO water treatment unit; 13. an electrothermal humidifier; 14. a hot mist nozzle; 15. an ultrasonic high-frequency atomization generator; 16. cold fog horn nozzle.
Detailed Description
As shown in fig. 1, a condensation test aging device for a medium voltage switchgear is characterized by at least comprising: the environment test box 9, the test article 8, the high-pressure environment unit, the condensation environment unit, the test support 10 and the test article 8, the test article 8 is placed on the test support 10 and forms the distance with ground, the test support 10 is in the environment test box 9 in the distance, the dry wall bushing 7 is arranged at the upper left end of the environment test box 9, the high-pressure environment unit passes through the dry wall bushing 7 and is introduced into the test article 8 in the environment test box 9, the condensation environment unit is arranged at the upper right end of the environment test box 9, the condensation environment unit is used for enabling the environment test box 9 to form the condensation environment, the high-pressure environment unit is used for providing 3.6-40.5 kV medium-voltage switching power supply for the test article 8, the environment test box 9 is used for controlling the condensation environment and controlling 3.6-40.5 kV voltage, the condensation environment and the 3.6-40.5 kV change are recorded, and the state record affecting the performance of the test article 8 is output.
The high-pressure environment unit includes: the thyristor voltage sag compensation unit 1, the three-phase (column) voltage regulator 2, the single/three-phase aging test power supply 3, the high-voltage ammeter 4, the power frequency protection resistor 5 and the capacitive voltage divider 6; 3.6-40.5 kV voltage is input to a three-phase (column type) voltage regulator 2 through a thyristor voltage drop compensation unit 1, the output end of the three-phase (column type) voltage regulator 2 is connected into a single/three-phase aging test power frequency test power supply 3, the single/three-phase aging test power frequency test power supply 3 divides three-phase voltage, and the three-phase voltage is respectively led into a three-phase end of a sample 8 in an environment test box 9 through a capacitor voltage divider 6 by three dry wall bushings 7 through a high-voltage ammeter 4 and a power frequency protection resistor 5 which are connected in series.
The thyristor voltage drop compensation unit 1 is used for increasing the voltage of the input side of the voltage regulator in ms-level response by increasing the conduction angle of the thyristor when the voltage drop of the sample side (possibly exceeding 5%) is caused by the increase of leakage current during the sample condensation test, so as to compensate the voltage drop of the sample side. The problem that the voltage regulator can not timely compensate the drop due to long voltage regulation time is solved.
The parameters of the thyristor voltage sag compensation unit 1 are shown in table 2.
As shown in fig. 2, the three-phase column voltage regulator 2 adopts a column voltage regulator with 600kVA, 10/0-10 kV, has better impedance voltage characteristic than a loop-transferring type voltage regulator and an induction type voltage regulator, is suitable for being used as a voltage regulating component of a pollution test complete device, and has impedance voltage of 3% -12% according to the percentage of the output voltage of the secondary side.
The power frequency test power supply 3 for the single/three-phase aging test is three-phase, has the capacity of 500kVA and the transformation ratio of 4 multiplied by 10/120kV, and can bear the unbalanced current effect during single-phase operation. The low voltage side consists of 4 series and parallel 10kV windings. The rated voltage and short-circuit impedance percentages of the transformer low/high voltage windings are also different due to the different connection of the low voltage windings, see fig. 3 and table 1:
table 1 Power frequency test Power supply and Voltage regulator matching Table for single/three-phase aging test
U 20 (%) the secondary output voltage percentage of the voltage regulator, Z kt Percentage of short-circuit impedance of voltage regulator, Z k (%) the percent short-circuit impedance of the filth test transformer.
The high-voltage ammeter 4 is an anti-interference type ammeter with a measurement range of 0-50A and 3 measurement ranges (0.1-5A, 1-20A and 1-50A), the measurement ranges can be automatically switched, and the measurement results can be transmitted to a remote measurement and control computer through optical fibers by the aid of the in-meter electrified optical conversion device.
The resistance value of the power frequency protection resistor 5 needs to be calculated empirically to meet the conditions that the short circuit current is more than or equal to 15A and the resistance/reactance ratio (R/X) is more than 0.1, and the values are 2.0kΩ, 1.0kΩ and 0.5kΩ according to the test voltage, and the specific table is shown in Table 2.
TABLE 2 short-circuit current and R/X value verification of test loop at typical test voltages
The design transformation ratio of the capacitive voltage divider 6 is 1000:1, and the capacitances of the high and low voltage arms are respectively: 2000pF and 2 mu F, the high voltage arm is selected to be 2000pF, so that the inertia of the power frequency test power supply is improved, and the falling of the test sample side power supply when the leakage current is larger is further reduced.
The rated voltage of the dry type wall bushing 7 is 72.5kV, the rated current is 630A, and the dry type wall bushing is pollution-resistant.
The environment test box 9 is used for providing a condensation environment for the test sample, and meanwhile, high voltage can be introduced by matching with the wall penetrating sleeve. The top of the test box is designed to be a slope top, the gradient is 2 degrees, and the purpose is to facilitate condensation of mist at the top during a condensation test, and slide down along the slope top to the periphery, so that water drops in the middle of a roof are prevented from dripping onto a test sample, and the test sample is prevented from being discharged to invalidate the test.
The main technical indexes are as follows:
temperature range: 20-60 ℃ (deviation + -1 ℃)
Relative humidity range: 20-100% (deviation + -5%)
Net size in environmental box: length, width and height: 4X 5X 4.5m (volume: 90 m)
Rate of temperature rise: 1.0-2.0 ℃/min
The heating mode is as follows: electrothermal blowing circulation heating
A sensor: platinum resistor Pt100 at 3 (upper, middle and lower)
Dehumidifier: heating and dehumidifying
The condensation environment unit comprises: the RO water treatment unit 12, the electric heating humidifier 13, the hot fog spray head 14, the ultrasonic high-frequency atomization generator 15 and the cold fog horn spray head 16; domestic water is processed into soft water through the RO water treatment unit 12 and is provided for the electric heating humidifier 13, the electric heating humidifier 13 is controlled to provide soft water with required temperature for the ultrasonic high-frequency atomization generator 15, atomization is formed by the ultrasonic high-frequency atomization generator 15, atomized steam liquid is output to the environment test box through the cold fog horn nozzle 16, and the environment test box is enabled to generate condensation.
The RO water treatment unit 12 stores tap water into a raw water tank, the water in the raw water tank is pressurized by an additional pump and filtered by a multi-medium filter, an activated carbon filter, a sodium ion softener and a precision filter, and the tap water is added by a primary high-pressure pump, and then is subjected to primary reverse osmosis and a pure water tank, and finally is subjected to secondary reverse osmosis to form soft water. The conductivity of the soft water can be controlled to be less than 5 mu S/cm, and the requirement of a DL/T593-2016 annex M condensation test can be met after the water mixing adjustment.
The environmental test chamber 9 includes a leakage current meter 11 connected between the environmental test chamber 9 and the ground for obtaining a leakage current of the environmental test chamber 9.
The leakage current meter 11 is used for measuring leakage current passing through the metal shell of the sample and entering the ground, and has the main technical parameters that:
measuring current type: AC power
Measuring range: 0-200 mu A, 0-2 MA, 0-250 mA, resolution: 1 mu A
Range switching: automatic switching
Anti-interference design: full shielding of metal material of shell
As shown in fig. 4A and 4B, the height of the test stand 10 is 0.65m (more than or equal to 0.5 m) according to GB/T3906-2020, and the length, width and height dimensions of the test stand are as follows: 3.3mX2.3mX0.65 m. The interior is a grid, so that fog generated in the test is not shielded, and the rapid formation of the condensate on the surface of the sample is facilitated. The grid center distance is 0.5m, the grid is formed by welding aluminum-zinc plated square steel pipes, the square steel pipes are 50 multiplied by 8mm in specification, the whole weight of the bracket is 3t, and the condensation test requirement of indoor high-voltage switch equipment of 40.5kV or below is met.
The electric heating humidifier 13 is used to heat soft water generated by the RO water treatment unit 12 to generate steam hot mist. The average particle size of the steam mist is 10-30 mu m, and the input quantity of the steam mist meets the requirements of GB/T4585-2004 ((0.05+/-0.01) kg/h.m: therefore, the steam fog amount meeting the environmental test chamber is designed to be: 4.5kg/h.
As shown in FIG. 5, the hot fog spray head 14 is made of stainless steel, is in a honeycomb shape (each aperture is 5 mm), and is arranged at the bottom of the environmental test chamber, so that the hot fog transpiration is facilitated.
As shown in fig. 6, the ultrasonic high-frequency atomizing generator 15 includes a compressed air source, an ultrasonic generator atomizing nozzle, and the like, which generates high oscillation by ultrasonic vibration, thereby enabling generation of extremely fine droplets, also referred to as "dry mist or cold mist". The ultrasonic high-frequency atomization generator can accurately control the size of liquid drops, on one hand, the requirement that the average diameter of the liquid drops is smaller than 20 mu m specified by a standard is met, and on the other hand, the ultrasonic high-frequency atomization generator can also be used for cooling an environment test box, so that the requirement that the test environment temperature required by DL/T593-2016 is smaller than or equal to 40 ℃.
The components and structures not specifically described in this embodiment are well known in the art and are not described in detail herein.
Claims (7)
1. The utility model provides a middling pressure switchgear condensation test ageing device which characterized in that includes at least: the environment test box (9), the test article (8), the high-voltage environment unit, the condensation environment unit and the test support (10), wherein the test article (8) is placed on the test support (10) and forms a distance with the ground, the test support (10) is arranged in the environment test box (9) in the middle, the dry type wall bushing (7) is arranged at the left end on the environment test box (9), the high-voltage environment unit penetrates through the dry type wall bushing (7) to be introduced into the test article (8) in the environment test box (9), the condensation environment unit is arranged at the right end on the environment test box (9), the high-voltage environment unit is connected with a power supply of the test article (8), and a 3.6-40.5 kV medium-voltage switching power supply is provided for the test article (8); the high-pressure environment unit includes: the device comprises a thyristor voltage drop compensation unit (1), a three-phase voltage regulator (2), a single/three-phase aging test power frequency test power supply (3), a high-voltage ammeter (4), a power frequency protection resistor (5) and a capacitive voltage divider (6); 3.6-40.5 kV voltage is input to a three-phase voltage regulator (2) through a thyristor voltage drop compensation unit (1), a single/three-phase aging test power frequency test power supply (3) is connected to the output end of the three-phase voltage regulator (2), the single/three-phase aging test power frequency test power supply (3) divides three-phase voltage, the three-phase voltage is respectively led into a three-phase end of a sample (8) in an environment test box (9) through three dry wall bushing (7) through a capacitive voltage divider (6) through a high-voltage ammeter (4) and a power frequency protection resistor (5) which are connected in series.
2. The aging device for the condensation test of the medium-voltage switchgear according to claim 1, wherein the three-phase voltage regulator (2) adopts a column voltage regulator of 600kVA and 10/0-10 kV, and the impedance voltage is 3% -12%; the power frequency test power supply (3) for the single/three-phase aging test is three-phase, has the capacity of 500kVA and the transformation ratio of 4 multiplied by 10/120kV, is used for bearing the unbalanced current effect during single-phase operation, and the low-voltage side of the power supply is composed of 4 groups of 10kV windings which can be connected in series and in parallel.
3. The aging device for the condensation test of the medium-voltage switchgear according to claim 1, wherein the high-voltage electricity meter (4) is anti-interference, the measuring range is 0-50A, the in-meter on-line electricity conversion device transmits the measuring result to the remote measuring and controlling computer through the optical fiber.
4. The aging device for the condensation test of the medium-voltage switchgear according to claim 1, wherein the design transformation ratio of the capacitive voltage divider (6) is 1000:1, and the capacitances of the high-voltage arm and the low-voltage arm are respectively: 2000pF and 2 uf.
5. The aging device for the condensation test of the medium voltage switchgear according to claim 1, wherein the condensation environment unit comprises: the device comprises an RO water treatment unit (12), an electric heating humidifier (13), a hot fog spray head (14), an ultrasonic high-frequency atomization generator (15) and a cold fog horn spray head (16); domestic water is processed into soft water through an RO water treatment unit (12) and is provided for an electric heating humidifier (13), the electric heating humidifier (13) is controlled to provide soft water with required temperature for an ultrasonic high-frequency atomization generator (15), atomization is formed by the ultrasonic high-frequency atomization generator (15), atomized steam liquid is output to an environment test box through a cold fog horn nozzle (16), and the environment test box generates condensation.
6. The aging device for the condensation test of the medium-voltage switchgear according to claim 5, wherein the RO water treatment unit (12) stores tap water into a raw water tank, the water in the raw water tank is pressurized by an increasing pump and filtered by a multi-medium filter, an activated carbon filter, a sodium ion softener and a precision filter, and the water is subjected to primary reverse osmosis and a pure water tank by a primary high-pressure pump and then subjected to secondary reverse osmosis to form soft water; the conductivity of the soft water can be controlled to be less than 5 mu S/cm, and the requirement of a DL/T593-2016 annex M condensation test can be met after the water mixing adjustment.
7. The aging device for the condensation test of the medium voltage switchgear according to claim 1, wherein the environmental test chamber (9) comprises a leakage current meter (11) connected between the environmental test chamber (9) and the ground for obtaining the leakage current of the environmental test chamber (9).
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