A solid-liquid micro / nano magnetic flux bridge method for balancing local overheating in electrical equipment

Abstract

This invention provides a solid-liquid micro / nano flux bridge method for balancing localized overheating in electrical equipment, comprising the following steps: S1: preparing a nanocrystalline coating; S2: air-drying and cleaning the air gap of the high-frequency transformer winding core, filling the air gap of the high-frequency transformer winding core with the nanocrystalline coating, filling to a distance of 1 mm from the edge of the air gap, spreading evenly, and air-drying and curing. The beneficial effects of this invention are: by using a given mixing procedure and a suitable ratio of nanocrystalline powder to AB glue, micro / nano flux bridges can be obtained for different needs. Filling these bridges into the air gaps of high-frequency transformers achieves the goal of solving the problem of localized overheating in the air gaps of the high-frequency transformer winding core.

Description

Technical Field

[0001] This invention belongs to the field of transformers, and in particular relates to a solid-liquid micro-nano magnetic flux bridge method for balancing local overheating in electrical equipment. Background Technology

[0002] Localized overheating is a difficult problem to solve in mechanical equipment, particularly in the air gaps of inductors, transformers, and other electrical equipment, especially in high-frequency transformers. This problem urgently needs to be addressed because air gap losses cause localized temperature rises, leading to overheating. Compared to other issues, temperature rise is the most serious. When the temperature of electrical equipment reaches 50°C, system performance degrades, affecting component efficiency and potentially causing damage. Solving the temperature rise problem can improve equipment efficiency by 10%–15% and simultaneously address safety hazards.

[0003] Air gaps are present in both large-scale electrical machinery and small-scale power electronic equipment, such as computers and their peripherals, office automation equipment, digital and analog communication equipment, home appliances, electromagnetic shielding, and aerospace applications. Reducing air gap losses and addressing the resulting localized overheating is a crucial issue. Summary of the Invention

[0004] In view of this, the present invention aims to propose a solid-liquid micro-nano magnetic flux bridge method for balancing local overheating in electrical equipment, so as to solve the problem of local overheating in the air gap caused by air gap loss.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A solid-liquid micro / nano magnetic flux bridge method for equalizing local overheating in electrical equipment, characterized by comprising the following steps:

[0007] (1) Nanocrystalline powder formulation

[0008] The iron-based nanocrystalline material formulation consists of Fe, Cu, Nb, Si, and B, and is formulated according to the chemical formula Fe73.5Cu1Nb3Si15.5B7. The ingredients are prepared based on the calculated mass percentage of each compound.

[0009] (2) AB glue selection

[0010] Component A is acrylic-modified epoxy or epoxy resin, or contains catalysts and other additives; Component B is modified amine or other curing agent, or contains catalysts and other additives.

[0011] Component A uses one or both of the existing acrylic-modified epoxy adhesives or epoxy resin adhesives, which employ existing technologies.

[0012] Component B uses an existing modified amine curing agent, which is a current technology.

[0013] By mixing nanocrystalline powder and AB glue, the properties of both are combined. Incorporating the nanocrystalline powder into the AB glue reduces its density within the air gap, thus significantly lowering the temperature rise. This solves both the temperature rise problem of nanocrystalline powder and the issues of localized overheating, air gap loss, and mechanical vibration in the air gap of high-frequency transformers. A solid-liquid micro-nano flux bridge method for balancing localized overheating in electrical equipment reduces the temperature within the air gap of high-frequency transformers by 10℃–20℃ and decreases air gap loss by 16%–19%.

[0014] (3) Mixing once

[0015] At room temperature, the prepared nanocrystalline powder and A glue are mixed. At this time, it is not sticky. According to different needs, different proportions of nanocrystalline powder and A glue are used to obtain the performance of micro-nano magnetic flux bridge under different proportions. Mix and stir for 10 minutes until uniform.

[0016] (4) Secondary mixing

[0017] At room temperature, B-type adhesive is mixed with the solid-adhesive mixture obtained from the first mixing in a certain proportion, and the mixture is stirred for 3 minutes until uniform. The resulting micro-nano magnetic flux bridge exhibits viscous properties.

[0018] (5) Air gap filling

[0019] The air gap of the high-frequency transformer winding core was dried and cleaned. The obtained micro-nano magnetic flux bridge was then filled into the air gap of the high-frequency transformer winding core, and the filling was extended to 1 mm from the edge of the air gap, and the coating was evenly applied.

[0020] (6) Air drying and curing

[0021] After air drying and curing at room temperature for 30 minutes, it reaches 50% of its maximum strength, and after 24 hours, it reaches its maximum strength of 60 N / m. Its operating temperature range is between -60℃ and 100℃.

[0022] Preferably, the nanocrystalline powder is selected from iron-based nanocrystalline powder and acrylic-modified epoxy or epoxy resin, modified amine or other hardener, all of which contain a catalyst.

[0023] The preferred mixing temperature for steps (3) and (4) is room temperature, 25°C.

[0024] The preferred temperature for the air drying and curing step (6) is room temperature 25°C, and the preferred wind speed is 0.3m / s to 0.5m / s.

[0025] Preferably, different nanocrystalline powder volumes and AB glue ratios can be used in high-frequency transformers with different power, frequency, and air gaps.

[0026] Preferably, different ratios of A and B adhesives can achieve different degrees of adhesion and hardening, which can be used in high-frequency transformers with different air gap sizes.

[0027] Preferably, the different proportions of nanocrystalline powder volume, A-type adhesive, and B-type adhesive are optimally matched with the air gap size of different high-frequency transformers.

[0028] The nanocrystalline powder has a high magnetic permeability of 1000-30000, can withstand high temperatures up to 500℃, and has a loss as low as 30W / kg.

[0029] The Young's modulus of the mixture of AB glue and nanocrystalline powder is between 3 MPa and 4 MPa; its adhesion is between 20,000 cps and 30,000 cps.

[0030] A micro / nano flux bridge was obtained by mixing AB adhesive (a mixture of A and B adhesives) with a bonding strength of 20,000–30,000 cps and a stiffness of 60 N / m with nanocrystalline powder having a permeability of 1,000–30,000 and a loss of 100 W / kg. Using a given mixing procedure and appropriate ratios of nanocrystalline powder to AB adhesive, micro / nano flux bridges were obtained to meet different requirements. These bridges were then filled into the air gaps of high-frequency transformers to solve the problem of localized overheating in the air gaps of the winding core.

[0031] Compared with existing technologies, the solid-liquid micro-nano magnetic flux bridge method for balancing local overheating in electrical equipment described in this invention has the following advantages:

[0032] 1. This patent relates to the ability of nanocrystalline powder to be distributed in the air gap at different densities, which reduces air gap loss and solves the problem of localized temperature rise. A solid-liquid micro-nano magnetic flux bridge method for balancing localized overheating in electrical equipment can reduce the air gap temperature of high-frequency generators by 15℃~20℃.

[0033] 2. After fabricating the components according to the required adhesion, hardening degree, and reduction of magnetic leakage, fill the air gap of the high-frequency generator to reduce local overheating. After filling the gap, the temperature of the high-frequency generator air gap decreased by 15℃~20℃.

[0034] 3. After fabricating the material according to the required adhesion, hardening degree, and reduction of magnetic leakage, fill the magnetic shielding air gap in the high-frequency wireless power transmission system to reduce magnetic leakage. After filling the gap, the magnetic leakage of the magnetic shielding part in the high-frequency wireless power transmission system is reduced by 10%. -5 T Attached Figure Description

[0035] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0036] Figure 1 This is a schematic flowchart of a solid-liquid micro-nano magnetic flux bridge method for balancing local overheating of electrical equipment according to an embodiment of the present invention.

[0037] Figure 2 This is a simulation diagram of a solid-liquid micro-nano magnetic flux bridge method for balancing local overheating of electrical equipment, as described in an embodiment of the present invention. Detailed Implementation

[0038] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0039] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0040] In specific embodiments 1, 2, and 3, component A is Leqin 7452 accelerator and component B is modified amine curing agent, which were purchased from Shandong Lifan Chemical Co., Ltd.

[0041] Implementation Case 1: At room temperature, a 1250kVA high-frequency transformer with a frequency of 50kHz was operated. After 1 hour of operation, the temperature at the core of the high-frequency transformer was measured to be 85℃. This is compared to Case 1.

[0042] Implementation Case 2: The volume of nanocrystalline powder, A-type adhesive, and B-type adhesive were mixed in a 1:1:1 ratio. The nanocrystalline powder and A-type adhesive were mixed and stirred for 10 minutes at room temperature until homogeneous. Then, the nanocrystalline powder and B-type adhesive were mixed and stirred for 1 minute until homogeneous. This mixture was then applied to the air gap of the wound core of a 1250kVA, 50kHz high-frequency transformer. After evenly applying the mixture as specified, the high-frequency transformer was run for 1 hour. The temperature at the transformer core was measured to be 50℃.

[0043] Implementation Case 3: The volume of nanocrystalline powder, A-type adhesive, and B-type adhesive were mixed in a ratio of 3:4:4. The nanocrystalline powder and A-type adhesive were mixed and stirred for 10 minutes at room temperature until homogeneous. Then, the nanocrystalline powder and B-type adhesive were mixed and stirred for 1 minute until homogeneous. This mixture was then applied to the air gap of the wound core of a 1250kVA, 50kHz high-frequency transformer. After evenly applying the mixture as specified, the high-frequency transformer was run for 1 hour. The temperature at the core of the high-frequency transformer was measured to be 60℃.

[0044] In specific embodiments 4 and 5, component A is a high-hardness epoxy resin potting compound, and the model of component A is Henkel Loctite Epoxy Resin Adhesive E-120HP. Component B is a modified amine curing agent, which was purchased from Shandong Lifan Chemical Co., Ltd.

[0045] Implementation Case 4: The volume of nanocrystalline powder, A-type adhesive, and B-type adhesive were mixed in a ratio of 2:1:1. The nanocrystalline powder and A-type adhesive were mixed and stirred for 10 minutes at room temperature until homogeneous. Then, the nanocrystalline powder and B-type adhesive were mixed and stirred for 1 minute until homogeneous. This mixture was then applied to the air gap of the wound core of a 1250kVA, 50kHz high-frequency transformer. After evenly applying the mixture as specified, the high-frequency transformer was run for 1 hour. The temperature at the core of the high-frequency transformer was measured to be 40℃.

[0046] Implementation Case 5: The volume of nanocrystalline powder, A-type adhesive, and B-type adhesive were mixed in a 3:1:1 ratio. The nanocrystalline powder and A-type adhesive were mixed and stirred for 10 minutes at room temperature until homogeneous. Then, the nanocrystalline powder and B-type adhesive were mixed and stirred for 1 minute until homogeneous. This mixture was then applied to the air gap of the wound core of a 1250kVA, 50kHz high-frequency transformer. After evenly applying the mixture as specified, the high-frequency transformer was run for 1 hour. The temperature at the transformer core was measured to be 50℃.

[0047] Case Comparison:

[0048] Comparisons between various cases revealed that the ratio of nanocrystalline powder to AB adhesive follows a quadratic function trend. The ratio of nanocrystalline powder to AB adhesive should be selected according to the requirements of different operating states of high-frequency transformers.

[0049] Implementation Case 1: After the solid-liquid micro-nano magnetic flux bridge method for equalizing local overheating of electrical equipment was used in the air gap of a high-frequency transformer, after the high-frequency transformer ran for 30 minutes, the air gap temperature of the high-frequency transformer using this method was reduced by 10℃ to 20℃ compared with the high-frequency transformer without this method, and its efficiency was increased by 10% to 15%.

[0050] Implementation Case 2: After the solid-liquid micro-nano magnetic flux bridge method for balancing local overheating of electrical equipment was used in the air gap of a high-frequency generator, after the high-frequency generator ran for 30 minutes, the air gap temperature of the high-frequency transformer using this method was reduced by 15℃ to 20℃ compared with the high-frequency generator without this method, and its efficiency was increased by 16% to 21%.

[0051] Implementation Case 3: After the solid-liquid micro-nano flux bridge method for balancing local overheating of electrical equipment was used in the air gap of a high-frequency motor, after the high-frequency motor ran for 30 minutes, the air gap temperature of the high-frequency transformer using this method was reduced by 15℃ to 20℃ compared with the high-frequency motor without this method, and its efficiency was increased by 17% to 20%.

[0052] Implementation Case 4: After the solid-liquid micro-nano magnetic flux bridge method for equalizing local overheating of electrical equipment was used in the air gap of the magnetic shielding in a high-frequency wireless power transmission system, after the system ran for 30 minutes, the leakage flux of the air gap of the high-frequency wireless power transmission system using the solution was reduced by 10-5T and the efficiency was increased by 0.5% to 1.0% compared with the high-frequency wireless power transmission system without the solution.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A solid-liquid micro-nano magnetic flux bridge method for balancing the local overheating of electrical equipment, characterized in that: Includes the following steps: S1: Preparation of nanocrystalline coatings; S2: Dry and clean the air gap of the high-frequency transformer winding core, fill the air gap of the high-frequency transformer winding core with nanocrystalline coating, fill it up to 1mm away from the edge of the air gap, spread it evenly, and let it dry and cure. The preparation of the nanocrystalline coating in step S1 includes the following steps: A1: Preparation of nanocrystalline powder; A2: Mix the nanocrystalline powder with adhesive A to obtain a solid-adhesive mixture; A3: Mix the obtained solid adhesive mixture with adhesive B to obtain a nanocrystalline coating; The preparation method of the nanopowder in step A1 includes the following steps: B1 : Fe 73.5 Cu1Nb3Si 15.5 B7 batching; B2: In an inert gas under a certain pressure, the material in B1 is thermally evaporated; B3: Then it condenses into nano-sized crystals. Pressing down and compacting this fine powder yields nanopowder.

2. A solid-liquid micro-nano flux bridge method for balancing the local overheating of electrical equipment, according to claim 1, characterized in that: The pressure in B2 is 0.1 kPa to 1 kPa.

3. The solid-liquid micro / nano magnetic flux bridge method for balancing local overheating in electrical equipment according to claim 1, characterized in that: The A-type adhesive in step A2 includes one or both of acrylic modified epoxy adhesive and epoxy resin adhesive.

4. The solid-liquid micro / nano magnetic flux bridge method for balancing local overheating in electrical equipment according to claim 1, characterized in that: The B-type adhesive in step A3 includes a modified amine curing agent.

5. The solid-liquid micro / nano magnetic flux bridge method for balancing local overheating in electrical equipment according to claim 1, characterized in that: The air drying and curing in step S2 includes air drying and curing at room temperature, with the air drying temperature being room temperature and the wind speed being 0.3 m / s ~ 0.5 m / s.

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