Electronic component optimization method of air-insulated switch cabinet and air-insulated switch cabinet

Abstract

The invention discloses an electronic component optimization method of an air-insulated switch cabinet and the air-insulated switch cabinet, and relates to the technical field of air-insulated switch cabinet optimizing.Structural parameters of a contact box used by an existing air-insulated switch cabinet are optimized in a simulation calculation mode, and the structural parameters of the contact box used by the existing air-insulated switch cabinet are optimized. The optimized contact box is subjected to an insulation test, and electronic elements such as an insulator, a circuit breaker, a current transformer, a voltage transformer and a lightning arrester are optimized, so that the safe operation of the air-insulated switch cabinet can be ensured to the greatest extent, the safe and stable operation of a power grid is further ensured, and the service life of the air-insulated switch cabinet is prolonged. The air-insulated switch cabinets produced by different manufacturers can be universally and interchangeably used within a certain range and a certain period at the same time, and the operation and maintenance convenience of the air-insulated switch cabinets is improved.

Description

Technical Field

[0001] The invention relates to the technical field of air-insulated switch cabinet optimization, and in particular to an electronic component optimization method of an air-insulated switch cabinet and an air-insulated switch cabinet. Background Art

[0002] As a metal-enclosed switching power equipment, switchgear is widely used in power grids and has a wide impact. Its performance is of great significance to ensuring the reliability of power supply. The existing high-voltage switchgear has defects in structural design and electrical layout, and the manufacturing process also has many imperfections. It is easily affected by the environment and other factors during the installation and operation and maintenance stages. In actual operation, many safety issues are exposed, which seriously affects the safe and stable operation of the power grid. Summary of the invention

[0003] The technical problem to be solved by the present invention is to address the deficiencies of the prior art and specifically provide an electronic component optimization method for an air-insulated switch cabinet and an air-insulated switch cabinet, as follows:

[0004] 1) In the first aspect, the present invention provides an electronic component optimization method for an air-insulated switchgear, and the specific technical solution is as follows:

[0005] Simulate the contact box with double shield structure used in air-insulated switchgear;

[0006] According to the simulation calculation results, the structural parameters of the contact box are optimized.

[0007] On the basis of the above scheme, the electronic component optimization method of an air-insulated switch cabinet of the present invention can also be improved as follows.

[0008] Furthermore, the method further includes: performing insulation testing on the optimized contact box.

[0009] Furthermore, the method also includes: providing protective covers on both sides of the insulators used in the air-insulated switch cabinet, and determining the structural parameters of the protective covers by using a simulation calculation method.

[0010] Furthermore, the method also includes: performing insulation test on the insulator after the protective cover is added.

[0011] Furthermore, the contact fingers of the circuit breaker used in the air-insulated switch cabinet are made of T2Y copper, the contact finger bracket and rivets of the circuit breaker are made of non-magnetic materials, the contact finger spring and contact seat of the circuit breaker are made of austenitic stainless steel, and the counter of the circuit breaker is a non-resettable counter.

[0012] Furthermore, the current transformer used in the air-insulated switchgear adopts a dry electromagnetic epoxy casting structure and passes the insulation test, partial discharge test, accuracy grade test, capacity test and volt-ampere characteristic test.

[0013] Furthermore, the voltage transformer used in the air-insulated switchgear adopts a dry electromagnetic epoxy cast fully insulated structure.

[0014] Furthermore, the arrester used in the air-insulated switchgear adopts a structure in the form of a silicone rubber jacket composite insulation.

[0015] Furthermore, the air-insulated switchgear is a 40.5 kV air-insulated switchgear, and the cabinet depth of the 40.5 kV air-insulated switchgear is 2800 mm or 3100 mm.

[0016] 2) In a second aspect, the present invention further provides an optimized air-insulated switchgear obtained by any of the above-mentioned electronic component optimization methods for air-insulated switchgear.

[0017] The beneficial effects of the present invention are as follows:

[0018] Through simulation calculation, the structural parameters of the contact box used in the existing air-insulated switchgear are optimized, and the insulation test is carried out on the optimized contact box. In addition, the electronic components such as insulators, circuit breakers, current transformers, voltage transformers and lightning arresters are optimized. This can ensure the safe operation of the air-insulated switchgear to the greatest extent, thereby ensuring the safe and stable operation of the power grid. Moreover, it can also meet the universal interchangeable use of air-insulated switchgear produced by different manufacturers within a certain range and a certain period, thereby improving the operation and maintenance convenience of the air-insulated switchgear. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments of the present invention:

[0020] Figure 1 A schematic flow chart of an electronic component optimization method for an air-insulated switchgear according to an embodiment of the present invention;

[0021] Figure 2 It is a top view schematic diagram of the high voltage shielding net;

[0022] Figure 3 It is the left view of the high voltage shielding net;

[0023] Figure 4 This is the expanded view of the ground shielding network;

[0024] Figure 5 It is a top view of the ground shielding network;

[0025] Figure 6 This is a schematic diagram of the structure before and after the contact box is optimized;

[0026] Figure 7 This is a rendering diagram of the optimized insulator;

[0027] Figure 8 This is the cross-sectional view of the optimized insulator. DETAILED DESCRIPTION

[0028] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0029] The technical solution of the present invention and how the technical solution of the present invention solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0030] like Figure 1 As shown, a method for optimizing electronic components of an air-insulated switchgear according to an embodiment of the present invention comprises the following steps:

[0031] S1. Simulate and calculate the contact box with double shielding structure used in air-insulated switchgear;

[0032] Among them, the air-insulated switchgear is a 40.5kV air-insulated switchgear, and the cabinet depth of the 40.5kV air-insulated switchgear is 2800mm or 3100mm.

[0033] Among them, the partial discharge level of the contact box with a double shielding structure at 1.1 times the rated voltage should be controlled within 3pC.

[0034] Among them, the contact box adopts a through-type design. The contacts of the circuit breaker inside the contact box are connected to the busbar through metal inserts. The circuit breaker chamber inside the air-insulated switch cabinet is connected to the busbar chamber and the cable chamber. The total axial length of the contact box is 720mm, the radial diameter is 280mm, and the axial distance between the tail of the contact box and the insulating mounting plate is 200mm. Since the busbar phase spacing inside the air-insulated switch cabinet is 360mm, and the phase spacing of the contacts of the circuit breaker inside the contact box is 300mm, the B-phase busbar outlet adopts a vertical outlet design, and the A-phase busbar outlet and C-phase busbar outlet of the contact box adopt a left and right oblique 60mm outlet design, so that the phase spacing of the lead-out busbar is 360mm. The contact box is installed on the metal mounting plate, and no longer overlaps each other to avoid small air gaps. At the same time, the air-insulated switch cabinet can meet the requirements of the metal armored structure.

[0035] When the rated current of the air-insulated switchgear is 1250A, the air-insulated switchgear adopts TMY-60×12 branch busbar, which can ensure the net distance of copper busbars is 300mm. When the rated current of the air-insulated switchgear is 2500A, 2-TMY-80×12 branch busbar is adopted, which can ensure the net distance of copper busbars is 280mm.

[0036] The double shielding structure includes a high voltage shielding net 1 and a ground shielding net 3, specifically:

[0037] 1) The high-voltage shielding net 1 is connected to the contact box and the busbar through metal inserts, and extends to the vicinity of the insulating hanging plate at the tail of the contact box. The high-voltage shielding net 1 is a cylindrical structure with an axial length of 282 mm and a diameter of 181 mm. Moreover, the high-voltage shielding net 1 is designed with a rectangular opening 2 near the busbar outlet of the contact box. The size of the rectangular opening 2 is designed to be 136 mm × 86 mm. Figure 2 and Figure 3 shown.

[0038] 2) The grounding shielding net 3 is fixed to the vertical metal partition inside the air-insulated switch cabinet through four metal parts 4, specifically connected by bolts. The grounding shielding net 3 is a cylindrical structure with an axial length of 63 mm and a diameter of 257 mm. Figure 4 and Figure 5 shown.

[0039] The metal part 4 can be a metal plate, or can be set to other structural shapes according to actual conditions. One end of the metal part 4 is fixed to the grounding shielding net 3, and the other end of the metal part 4 is provided with an opening for passing a bolt.

[0040] The ends of the high-voltage shielding net 1 and the grounding shielding net 3 are both curled to make the field strength at the ends uniform, and the curling radius is not less than 1.5 mm.

[0041] S2. According to the simulation calculation results, the structural parameters of the contact box are optimized.

[0042] With the help of 3D finite element analysis software, the electric field verification and insulation optimization research of the contact box design was carried out. The electric field distribution of the contact box in the working position and the test position was calculated respectively. Specifically:

[0043] 1) When the contact box is in the working position, the moving side conductor and the static side conductor inside the contact box are in the closed position. During the simulation calculation, a power frequency withstand voltage of 95kV is applied to the conductive busbar and the high-voltage shielding net 1 inside the middle phase contact box, and a zero potential is applied to the conductive busbar and the high-voltage shielding net 1 inside the side phase contact box.

[0044] 2) When the contact box is in the test position, a power frequency withstand voltage of 95kV is applied to the conductive busbar inside the contact box above the middle phase and the high-voltage shielding net 1, and zero potential is applied to the conductive busbar inside the contact box below the middle phase and the side phase and the high-voltage shielding net 1. Zero potential is applied to the grounding shielding net 3 of the three-phase contact box and the contact box hanging plate, and zero potential is applied to the surface of the air-insulated switchgear.

[0045] According to the field strength control requirements, under 95kV power frequency withstand voltage, the maximum field strength inside the epoxy material does not exceed 9.38kV / mm, and the maximum field strength on the surface of the epoxy material does not exceed 2kV / mm. Therefore, it is necessary to control the electric field strength at each key position of the contact box. The key positions can be determined through simulation calculations or based on experience.

[0046] The potential distribution of the contact box of the 40.5kV air-insulated switchgear when it is in the working position is simulated and calculated, and the electric field distribution of the contact box of the 40.5kV air-insulated switchgear when it is in the working position is simulated and calculated. According to the simulation results, the potential and electric field distribution rules on the surface and inside of the contact boxes of each phase are basically similar. On the surface of the contact box, the field strength in the contact outlet area of ​​the circuit breaker is relatively low, and a local field strength concentration area appears near the connection between the insulating hanging plate of the contact box and the outgoing line side of the busbar of the contact box body. Since the distance between the middle phase contact box and the side phase contact box is relatively close, the high field strength is mainly distributed at both ends of the contact box body.

[0047] The potential distribution at the central cross section inside the contact box is simulated and calculated. According to the simulation results, it can be seen that, affected by the high-voltage shielding net 1 inside the contact box, a low field strength area is formed in the area between the contact of the circuit breaker and the high-voltage shielding net 1 inside the contact box, which effectively reduces the field strength of the air gap inside the contact box. However, a high field strength area is formed between the grounding shield and the high-voltage shield inside the contact box insulation, and the field strength at the ends of the high-voltage shielding net 1 and the grounding shielding net 3 is relatively high.

[0048] Moreover, from the experience of field operation, the interior of the contact box will inevitably have problems such as dirt accumulation under long-term operation conditions. Under environmental conditions such as humidity and condensation, it may cause local high-field strength areas inside the contact box, and even cause internal discharge of the contact box. The use of a double shielding structure can lead the high-field strength area to the inside of the insulating material, thereby effectively reducing the field strength of the air gap inside the contact box. Since the insulation strength of the air gap inside the contact box is significantly lower than that of the solid insulating material, it can effectively reduce the risk of internal surface discharge caused by special environmental conditions such as dirt accumulation on the inner surface of the contact box, thereby improving the safety and reliability of the contact box operation.

[0049] Optionally, an image of the contact box is obtained and identified to determine whether the surface of the contact box is damaged or dirty, and if so, a reminder is issued. Specifically:

[0050] The collected images of the contact box are preprocessed, including denoising, graying, adjusting the image size, etc., and the preprocessed image data is divided into a training set, a validation set, and a test set. The training set is used to train the model, the validation set is used to adjust the hyperparameters of the model, and the test set is used to evaluate the performance of the model. The appropriate loss function (such as the cross entropy loss function) and optimizer (such as the Adam optimizer) are selected to train the neural network. Specifically, the neural network is trained using the training set, the loss is calculated through forward propagation, and the weights of the model are updated through back propagation. During the training process, the validation set can be used to monitor the performance of the model and make adjustments as needed.

[0051] Among them, overfitting can be prevented by using regularization technology, data enhancement technology, early stopping method and other methods; underfitting problems can be solved by increasing model complexity, extending training time and other methods.

[0052] When the number of samples in each category in the dataset is unbalanced, the cross entropy loss function may make the model more biased towards predicting the category with a larger number. Use the weighted cross entropy loss function to give a larger weight to the minority class to solve this technical problem.

[0053] Optionally, during training, periodically monitor the cross entropy loss value and the performance of the model on the validation set.

[0054] Optionally, to prevent the model from overfitting, in the Adam optimizer, you can add a weight decay term to further control the complexity of the model. This is achieved by adding a penalty term proportional to the weight size to the loss function.

[0055] Optionally, during the model training process, multiple similar weights are shared as one weight to reduce the number of model parameters and improve training efficiency, wherein all weights within a preset range of any weight are similar weights of that weight, and that weight is used as the shared weight, or the mean of all weights within the preset range of that weight is used as the shared weight.

[0056] The simulation calculates the potential distribution of the high-voltage shielding mesh 1 inside the contact box, the electric field distribution of the high-voltage shielding mesh 1 inside the contact box, the potential distribution of the grounding shielding mesh 3 inside the contact box, and the electric field distribution of the grounding shielding mesh 3 inside the contact box. According to the simulation calculation results, the maximum field strength on the surface of the grounding shielding mesh 3 is 8.17 kV / mm, and the maximum field strength on the surface of the high-voltage shielding mesh 1 is 9.37 kV / mm, both of which are lower than the control requirement of 9.38 kV / mm. The maximum field strength on the surface of the contact box is 1.71 kV / mm, which is lower than 2 kV / mm and meets the field strength control requirements.

[0057] Through simulation calculation and analysis, it is found that the maximum field strength on the surface of the high-voltage shielding net 1 inside the contact box exceeds the control value of 9.38kV / mm under the test position condition, and the structural parameters of the contact box need to be optimized. By adjusting the size parameters of the shielding space inside the insulating parts of the contact box, the electric field distribution inside and on the surface of the contact box can be optimized to a certain extent. Figure 6 As shown, the insertion depth of the high-voltage shielding net 1 is increased by 10 mm.

[0058] Table 1 shows the maximum field strength values ​​of each key position of the optimized contact box under the working position and test position conditions. As the depth of the high-voltage shielding net 1 inside the contact box insulation increases, the distance between the high-voltage shielding net 1 and the end of the grounding shielding net 3 increases accordingly, and the field strength on the surface of the grounding shielding net 3 increases to a certain extent. Under the working position condition, the maximum field strength at the end increases from 8.17kV / mm to 9.25kV / mm; the field strength on the surface of the high-voltage shielding net 1 decreases to a certain extent. Under the working position condition, the maximum field strength at the end decreases from 9.37kV / mm to 7.7kV / mm.

[0059] Table 1:

[0060]

[0061]

[0062] The increase in the depth of the high-voltage shielding net 1 of the contact box has little effect on the surface field strength of the insulating parts. The maximum field strength of the insulating parts surface under the working position condition slightly increases from 1.71kV / mm to 1.79kV / mm. After optimization, the maximum field strength of the high-voltage shielding net 1 and the grounding shielding net 3 inside the contact box under the working position condition and the test position condition is lower than 9.38kV / mm, which can meet the control requirements; the maximum field strength of the insulating parts surface under the working position condition and the test position condition meets the field strength control value of 2kV / mm.

[0063] Optionally, in the above technical solution, it also includes:

[0064] S3. Conduct insulation test on the optimized contact box, including:

[0065] 1) Test position working condition insulation test:

[0066] The optimized contact box was subjected to insulation test under the test position condition. During the test, the busbar was a double busbar structure, and the contact arm size inside the contact box was Φ90mm. Table 2 gives the specific results of the insulation test. The corona inception voltage and extinction voltage of each contact box sample were greater than 52kV (1.3Ur), and the partial discharge was less than 3pC, meeting the design requirements.

[0067] Table 2:

[0068]

[0069] 2) Working position insulation test:

[0070] The optimized contact box was subjected to insulation test under working condition. During the test, the busbar was a double busbar structure and the contact arm size inside the contact box was Φ90mm. Table 3 shows the specific results of the insulation test. The corona initiation voltage and extinction voltage of each contact box sample were greater than 52kV (1.3U r ), the partial discharge is less than 3pC, meeting the design requirements.

[0071] Table 3:

[0072]

[0073] Optionally, the method further includes: performing a lightning impulse test on the optimized contact box, applying a lightning impulse voltage peak of 185 kV, 15 times for each positive and negative polarity, and the test results show that the optimized contact box passes the lightning impulse test.

[0074] Optionally, in the above technical solution, it also includes:

[0075] S4. Protective covers 5 are arranged on both sides of the insulators used in the air-insulated switch cabinet, and structural parameters of the protective covers 5 are determined by using a simulation calculation method.

[0076] Among them, two protective covers 5 and a plate for connecting the two protective covers 5 are integrated, and the plate is connected to the insulator by a threaded connection. When the insulating partition is removed from the air-insulated switch cabinet, the static contact area of ​​the grounding switch is an exposed electrode with many sharp points, which poses a greater risk of causing discharge under lightning impulse voltage. To this end, without changing the installation dimensions of the existing insulators and without interfering with product assembly, a new insulator is improved and designed, and protective covers 5 are added to both sides of the top of the existing insulator, thereby increasing the insulation clearance between the exposed electrodes in this area, such as Figure 7 and Figure 8 shown.

[0077] The optimized insulator does not change the installation dimensions of the existing sensor insulator and does not interfere with product assembly. By adding insulating protective plates on both sides of the top of the existing conventional insulator and using integral epoxy casting, the floating potential is eliminated. The protective cover 5 on both sides of the insulator is equipped with reinforcing ribs 6 to ensure its reliable mechanical strength.

[0078] Optionally, for air-insulated switchgear with a rated current of 1250A, a busbar with a specification of 60mm×12mm is used. After using optimized insulators, the insulation clearance between exposed electrodes in this area is significantly increased, effectively improving the insulation margin.

[0079] Optionally, for air-insulated switchgear with a rated current of 2500A, a 100mm×10mm busbar is used. After using optimized insulators, the net distance between exposed electrodes in this area is significantly improved.

[0080] In order to achieve a reasonable layout of the cable room and ensure the feasibility of component installation, during actual installation, it is also possible to consider using integrated insulators for phases A and C and ordinary supporting insulators for phase B.

[0081] With the help of 3D finite element analysis software, an electric field verification study was conducted on the insulator design of 40.5kV air-insulated switchgear. The electric field distribution of the optimized insulator was simulated and calculated. According to the simulation results, the highest field strength on the insulator surface is 1.414kV / mm, and the high field strength area mainly appears near the high-voltage side electrode of the insulator. The presence of insulating covers at both ends of the insulator can effectively improve the net distance between the exposed electrodes in the area and suppress the discharge hazards in this area.

[0082] Optionally, in the above technical solution, it also includes:

[0083] S5. Perform insulation tests on the insulator after adding the protective cover 5. Specifically, perform multiple insulation tests such as partial discharge, power frequency withstand voltage, and lightning impulse on the insulator after adding the protective cover 5. The insulation test results are shown in Table 4. The insulation test results show that the insulator after adding the protective cover 5 has passed multiple insulation tests.

[0084] Table 4:

[0085] Corona inception voltage Extinguishing voltage Power frequency withstand voltage Lightning strike 63.10kV 57.35kV 110kV 210kV

[0086] Optionally, in the above technical solution, the material of the contacts of the circuit breaker used in the air-insulated switchgear is T2Y copper, the materials of the contact bracket and rivets of the circuit breaker are both non-magnetic materials, the contact spring and contact seat of the circuit breaker are both austenitic stainless steel, and the counter of the circuit breaker is a non-resettable counter.

[0087] Optionally, the circuit breaker uniformly adopts a spring operating mechanism and a circuit breaker body integrated structure, and the circuit breaker trolley grounding method can adopt the friction contact method between the bottom contact of the trolley and the main grounding copper bar of the switch cabinet. The main inspection items of the circuit breaker should include insulation test, mechanical properties, loop resistance, etc. The "working position" and "test position" signs are printed on the protective plate of the trolley room to indicate the travel position of the trolley.

[0088] The technical requirements for circuit breakers mainly include:

[0089] 1) The circuit breaker control circuit should not have a rectifier circuit.

[0090] 2) The material of the contact finger is T2Y copper, and the thickness of a single contact finger is 3±0.15mm. The contact finger bracket and rivets should be made of non-magnetic materials. The material of the circuit breaker contact finger spring and contact seat should comply with the 06Cr19Ni10 austenitic stainless steel required by the Q / GDW11717-2017 "Technical Supervision Guidelines for Metals of Power Grid Equipment" standard, with uniform structure and no local deformation.

[0091] 3) The size specifications of the four compression springs of each plum blossom contact should be unified (spring wire diameter, spring outer diameter and spring free length are the same) to ensure consistent output pressure. When the contact design compression force is certain, it is advisable to use a spring with a larger stiffness coefficient to keep it in a relatively small deformation working state to ensure its fatigue life. The contact depth between the circuit breaker trolley contact and the cabinet static contact meets 15-25mm.

[0092] 4) The isolating trolley contacts, circuit breaker trolley contacts and static contacts in the switch cabinet should be made of T2 copper, the thickness of the silver plating layer on the sliding conductive contact surface should be no less than 8μm, and the hardness should be no less than 120HV. The contact surface roughness Ra should not be higher than 1.6μm.

[0093] 5) When the circuit breaker leaves the factory, the opening and closing stroke characteristic curve of the circuit breaker must be provided, and the reference opening and closing stroke characteristic curve of this type of circuit breaker must be provided.

[0094] 6) The circuit breaker counter should be of non-resettable type.

[0095] 7) If the circuit breaker uses a vacuum circuit breaker, the allowable storage period of the vacuum arc extinguishing chamber shall not be less than 20 years, and the vacuum degree of the arc extinguishing chamber shall not be greater than 1.33×10-3Pa when leaving the factory.

[0096] 8) The capacitor bank circuit breaker should meet the C2 level requirements and undergo whole machine aging.

[0097] 9) To facilitate gas testing sampling and replenishment, the circuit breaker should be equipped with appropriate valves.

[0098] Optionally, the main test items of the grounding switch should include insulation test, speed, contact clamping force test, etc. The closing and opening direction of the grounding switch should be closed from bottom to top and opened from top to bottom. The flexible connecting wire is uniformly installed with a 120mm on each side. 2 Braided copper tape with transparent sheath. Manual operation is selected according to project needs.

[0099] The grounding switch should match the rated short-time withstand current and rated peak withstand current of the main switch. When the distance between the grounding switch blade in the cabinet and the grounding switch operating shaft does not meet 300mm, a conjoined insulator or an insulating operating rod can be used. The strength of the grounding switch operating spring compression parts should match, and plastic or cast aluminum parts are prohibited.

[0100] Optionally, in the above technical solution, the current transformer used in the air-insulated switchgear adopts a dry electromagnetic epoxy casting structure and passes insulation test, partial discharge test, accuracy grade test, capacity test and volt-ampere characteristic test.

[0101] Optionally, for the overhead incoming line solution, the rated current of the switch cabinet branch busbar is a pillar-type current transformer, which is installed at the bottom of the cable room, and the number of secondary windings of the current transformer is 4. For the cable incoming line solution, a pillar-type current transformer is used, which is installed at the bottom of the cabinet cable room, and the number of secondary windings of the current transformer is 4. For the cable outgoing cabinet solution, a pillar-type current transformer is used, which is installed at the bottom of the cabinet cable room, and the number of secondary windings of the current transformer is 3. For the segmented cabinet solution, a pillar-type current transformer is used, which is installed at the bottom of the cabinet cable room, and the number of secondary windings of the current transformer is 2 (measurement, protection).

[0102] Optionally, the preferred transformation ratio series of the current transformer is: 100 / 5(1), 200 / 5(1), 400 / 5(1), 600 / 5(1), 800 / 5(1), 1200 / 5(1), 2500 / 5(1). The intermediate tap can be selected according to the specific project, and the preferred scheme is as follows:

[0103] 1) Metering and measuring windings: 400 / 5(1) can be realized as 200 / 5(1) by means of a center tap; 800 / 5(1) can be realized as 600 / 5(1) by means of a center tap; 1200 / 5(1) and 2500 / 5(1) do not have a center tap.

[0104] 2) Protection winding: 100 / 5(1), 400 / 5(1), 800 / 5(1), 1200 / 5(1), 2500 / 5(1), without intermediate tap.

[0105] To ensure that the current transformer can be replaced without changing the branch busbar when the capacity is increased later, the dimensions of the transformer should be uniformly specified. According to the maximum protection multiples 5P20 and 5P30 parameters, the following dimensions are consulted and recommended. If the protection multiple is lower than 5P20, the dimensions are all selected according to 5P20. In summary, the current transformer parameters are shown in Table 5.

[0106] Table 5:

[0107]

[0108] Optionally, in the above technical solution, the voltage transformer used in the air-insulated switchgear adopts a dry electromagnetic epoxy cast fully insulating structure.

[0109] The main test items of voltage transformers should include insulation, partial discharge (under 1.1Ur, the maximum partial discharge is ≤10pC, Ur is the highest operating voltage), excitation characteristics (excitation characteristic curve, the difference of excitation characteristic curve in the same cabinet is ≤30%), accuracy, inflection point voltage test under 1.9Ur, three-phase unbalance (1V), rated voltage factor (1.2 times continuous, 1.9 times 8h), etc. The line side PT uses 1 winding, which can be installed as a single or 2 V / V connections; the bus PT uses 3 or 4 windings or other, that is, Y / Y / Y / Δ or Y / Y / Y / Y / Δ or other connections. The main parameters of the voltage transformer are shown in Table 6.

[0110] Table 6:

[0111]

[0112] Optionally, in the above technical solution, the arrester used in the air-insulated switchgear adopts a structure of a silicone rubber jacket composite insulation form. The main parameters of the arrester are shown in Table 7.

[0113] Table 7:

[0114]

[0115] In the above embodiments, although the steps are numbered S1, S2, etc., these are only specific embodiments given by the present invention. Those skilled in the art may adjust the execution order of S1, S2, etc. according to actual conditions, which is also within the protection scope of the present invention. It can be understood that in some embodiments, some or all of the above embodiments may be included.

[0116] The present invention also provides an optimized air-insulated switch cabinet obtained by any of the above-mentioned electronic component optimization methods for air-insulated switch cabinets.

[0117] In the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0118] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0119] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for optimizing electronic components of an air-insulated switchgear, characterized in that: include: Simulate the contact box with double shield structure used in air-insulated switchgear; According to the simulation calculation results, the structural parameters of the contact box are optimized.

2. The electronic component optimization method of an air-insulated switchgear according to claim 1, characterized in that: Also includes: Conduct insulation test on the optimized contact box.

3. The electronic component optimization method of an air-insulated switchgear according to claim 1, characterized in that: Also includes: Protective covers are arranged on both sides of insulators used in air-insulated switchgear, and structural parameters of the protective covers are determined by using a simulation calculation method.

4. The electronic component optimization method of an air-insulated switchgear according to claim 3, characterized in that: Also includes: Conduct insulation test on the insulator after adding the protective cover.

5. The method for optimizing electronic components of an air-insulated switchgear according to claim 1, characterized in that: The contact fingers of the circuit breaker used in the air-insulated switch cabinet are made of T2Y copper, the contact finger bracket and rivets of the circuit breaker are made of non-magnetic materials, the contact finger spring and contact seat of the circuit breaker are made of austenitic stainless steel, and the counter of the circuit breaker is a non-resettable counter.

6. The electronic component optimization method of an air-insulated switchgear according to claim 1, characterized in that: The current transformer used in the air-insulated switch cabinet adopts a dry electromagnetic epoxy casting structure and passes insulation test, partial discharge test, accuracy grade test, capacity test and volt-ampere characteristic test.

7. The method for optimizing electronic components of an air-insulated switchgear according to claim 1, characterized in that: The voltage transformer used in the air-insulated switch cabinet adopts a dry electromagnetic epoxy casting full-insulation structure.

8. The method for optimizing electronic components of an air-insulated switchgear according to claim 1, characterized in that: The lightning arrester used in the air-insulated switch cabinet adopts a structure in the form of a silicone rubber jacket composite insulation.

9. The electronic component optimization method of an air-insulated switchgear according to any one of claims 1 to 8, characterized in that: The air-insulated switch cabinet is a 40.5 kV air-insulated switch cabinet, and the cabinet depth of the 40.5 kV air-insulated switch cabinet is 2800 mm or 3100 mm.

10. An optimized air-insulated switchgear obtained by the electronic component optimization method of an air-insulated switchgear according to any one of claims 1 to 9.

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