Boost inductor for reducing inverter loss

Abstract

The invention provides a boost inductor capable of reducing inverter loss, and relates to the technical field of inverters, a magnetic core is made of a graded nanocrystalline soft magnetic composite material, the magnetic core is composed of iron-based nanocrystalline alloy particles, the particle size gradually changes from 10-15 microns of a central layer to 25-50 microns of an outer layer, a gradient structure is formed through a layered compaction process, and the thickness of the gradient structure is larger than that of the iron-based nanocrystalline alloy particles. The winding comprises a main winding and an auxiliary winding, the main winding is a high-conductivity oxygen-free copper wire, the auxiliary winding is a carbon nanotube reinforced copper composite wire containing a multi-walled carbon nanotube with the weight ratio of 1%, the main winding is wound in a standard spiral mode, and the auxiliary winding is inserted between coils of the main winding in a staggered mode and is compacted in a layered mode to form a gradient structure; and the magnetic field distribution is obviously optimized, the eddy current loss is reduced, the stability of the gradient structure is ensured, and the magnetic core has the high saturation flux density of the nanocrystalline alloy and the low loss characteristic of the graded nanocrystalline soft magnetic composite material, so that the effect of improving the high-frequency working efficiency of an inverter is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of inverters, and particularly to a boost inductor for reducing the losses of an inverter. Background Art

[0002] According to a soft magnetic core for a high-power inverter power supply and a manufacturing method thereof disclosed in "CN101477868B" with a Chinese publication number, the magnetic core is wound by an iron-based amorphous nanocrystalline strip. The components of the magnetic core are by mass fraction: Fe: 81% - 85%, Co: 0.01% - 5%, Si: 7% - 9%, B: 1.5% - 2.5%, Cu: 1% - 2%, M: 4% - 7%, M': 0.001% - 0.04%, where M is one or more of Nb, Mo, V, W, Ta, and M' is at least one of Al and Ti. The magnetic core is annealed in a protective atmosphere or in vacuum. When annealing, the position of the magnetic core in the furnace can be moved or rotated. The heat preservation temperature is 520 - 600 °C, the heat preservation time is 1 - 2 hours, and the heating rate is 100 °C / hour. The magnetic core manufactured by the above method has lower losses and better manufacturing process performance. It not only has excellent soft magnetic properties, but also the subsequent processing after heat treatment can be applicable to a variety of process methods.

[0003] The above patent document and the prior art have the following technical problems when in use: Problem one: The magnetic core materials (such as ferrite or ordinary iron-based alloys) used in traditional inverter boost inductors often have poor performance under high-frequency working conditions. The eddy current loss and hysteresis loss of the magnetic core are large, resulting in serious energy dissipation. Especially in high-frequency applications such as photovoltaic inverters, the efficiency drops significantly. Problem two: Most of the winding materials of existing inverter inductors use a single copper wire (such as ordinary oxygen-free copper wire). Although the DC resistance is low, under high-frequency conditions, due to the influence of the skin effect and proximity effect, the AC resistance increases significantly, resulting in a large increase in copper loss. The single-material design cannot effectively handle the DC and AC components existing simultaneously in the inverter. Especially in scenarios with large high-frequency ripples, the loss problem is particularly prominent, limiting the overall performance of the inductor. Problem three: The winding processes of existing inverter inductors (such as simple spiral winding or random winding) often lead to uneven magnetic field distribution and obvious magnetic leakage. Especially under high-frequency and high-power conditions, the parasitic capacitance and magnetic leakage loss increase significantly. These problems not only increase the overall loss of the inductor, but also affect the stability of the inverter, resulting in increased electromagnetic interference or a decline in the performance of the inductor. Summary of the Invention

[0004] Technical Problems to be Solved Aiming at the deficiencies of the prior art, the present invention provides a boost inductor for reducing the losses of an inverter, and solves the following problems: 1. Aiming at the problems of large core material loss and low high-frequency efficiency; 2. Aiming at the problems of high winding copper loss and significant high-frequency AC loss; 3. Aiming at the problems of uneven magnetic field distribution caused by single winding, serious magnetic leakage and parasitic effects.

[0005] Technical Solution

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions: A boost inductor for reducing the loss of an inverter, including a boost inductor composed of a magnetic core and a winding. The magnetic core adopts a hierarchical nanocrystalline soft magnetic composite material magnetic core. The hierarchical nanocrystalline soft magnetic composite material magnetic core is composed of iron-based nanocrystalline alloy particles, and the particle size gradually changes from 10 - 15 microns in the central layer to 25 - 50 microns in the outer layer, forming a gradient structure through a layered compaction process. The iron-based nanocrystalline alloy includes a total mass percentage of iron and cobalt of not less than 73%, and an insulating coating is provided on the outside of the iron-based nanocrystalline alloy. The winding includes a main winding and an auxiliary winding. The main winding is made of high-conductivity oxygen-free copper wire and is used to process direct current. The auxiliary winding is a carbon nanotube-reinforced copper composite wire containing 1% by weight of multi-walled carbon nanotubes and is used to process AC ripples. The main winding is wound in a standard spiral manner, the auxiliary winding is inserted between the turns of the main winding in a staggered manner, and the main winding and the auxiliary winding are connected in parallel.

[0007] Preferably, the composition of the iron-based nanocrystalline alloy by mass fraction is: cobalt: 5 - 10%, niobium: 2 - 2.5%; copper: 0.8 - 1%; silicon: 11 - 12%, boron: 8 - 9%; manganese: 1 - 1.5%; adjust the content according to cobalt so that Fe + Co ≥ 73%.

[0008] Preferably, the hierarchical nanocrystalline soft magnetic composite material magnetic core has a three-layer gradient structure, namely the central layer, the intermediate layer and the outer layer. The particle size of the central layer is 10 - 15 microns, the particle size of the intermediate layer is 15 - 25 microns, and the particle size of the outer layer is 25 - 50 microns. The insulating coating is epoxy resin or ceramic material, and the coating thickness is 0.1 - 0.5 microns.

[0009] Preferably, the forming method of the magnetic core includes the following steps: Sp1: Alloy production: Prepare the iron-based nanocrystalline alloy through rapid solidification technology, and the cooling rate is 10 5 -10 6 K / s; Sp2: Particle preparation: Grind the alloy into three types of particles with sizes of 10 - 15 microns, 15 - 25 microns and 25 - 50 microns, and control the particle size distribution within ±5%; Sp3: Insulating Coating: Epoxy resin or ceramic is coated using spraying or dipping process, with uniform coating thickness to prevent eddy current between particles; Sp4: Layered Compaction: Compaction is carried out in layers using a mold. First, the central layer is compacted, then the intermediate layer and the outer layer are compacted, and the compaction pressure is 100 - 200 MPa; Sp5: Heat Treatment: Annealing is carried out at 400 - 600 °C for 1 - 2 hours; Sp6: Final Machining: Machined to the target shape, keeping the gradient structure intact.

[0010] Preferably, the oxygen - free copper wire of the main winding is of C10100 - TU0 type, with conductivity between 99% - 101% IACS, wire diameter of 0.5 - 1.5 mm, the insulating layer is polyimide or polyester, with thickness of 0.05 - 0.1 mm, and the withstand voltage range is 220 V - 10 kV.

[0011] Preferably, the carbon nanotube - enhanced copper composite wire of the auxiliary winding is composed of high - purity oxygen - free copper and 1% by weight of multi - wall carbon nanotubes, with wire diameter of 0.2 - 0.5 mm, and the insulating layer thickness of 0.03 - 0.08 mm.

[0012] Preferably, the winding process of the winding includes the following steps: Sp1: Calculate the number of turns N of the main winding and the number of turns M of the auxiliary winding, where N is determined based on the inductance and direct current, and M is 0.3 - 0.5 times of N; Sp2: The main winding is wound N turns in a standard spiral manner, and the tension fluctuation is controlled within ±1 N; Sp3: The auxiliary winding is wound M turns in a staggered manner, with each turn misaligned 15° - 30° relative to the main winding, and the tension fluctuation is controlled within ±0.5 N; Sp4: The two are connected in parallel, with the contact resistance lower than 0.01 Ω.

[0013] Preferably, the winding process of the winding uses a high - precision winding machine. The winding speed of the main winding is 5 - 10 revolutions per second, and the winding speed of the auxiliary winding is 10 - 15 revolutions per second. The misalignment angle of the auxiliary winding is controlled by a precision positioning device, and the angle deviation does not exceed ±1°.

[0014] Preferably, after the boost inductor is wound, quality inspection is carried out, and the specific inspection contents include: The inductance is measured every 50 turns, and the deviation is controlled within ±2%; Use X - ray flaw detection to check for internal defects of the winding; Overall performance testing, including withstand voltage testing from 220 V to 10 kV, direct current resistance testing, and alternating current loss testing.

[0015] Beneficial Effects

[0016] The present invention provides a boost inductor for reducing the losses of an inverter, which has the following beneficial effects: 1. The present invention adopts a hierarchical nanocrystalline soft magnetic composite core, with the particle size gradually changing from 10 - 15 microns in the center to 25 - 50 microns in the outer layer. A gradient structure is formed through layered compaction, which can significantly optimize the magnetic field distribution and reduce eddy current losses. By utilizing the high permeability characteristics of the fine particles (10 - 15 microns) in the central layer, the magnetic flux in the strong magnetic field region is effectively constrained, improving the magnetic properties of the core under high-frequency conditions. At the same time, the larger particles (25 - 50 microns) in the outer layer reduce eddy current losses in the weaker magnetic field region, reducing the energy dissipation caused by the high-frequency alternating magnetic field. The layered compaction process ensures the stability of the gradient structure, enabling the core to possess both the high saturation magnetic induction intensity of the nanocrystalline alloy and the low-loss characteristics of the hierarchical nanocrystalline soft magnetic composite, thereby achieving the effect of improving the high-frequency operating efficiency of the inverter. It is applicable to high-frequency application scenarios such as photovoltaic inverters, can significantly reduce the core losses, and improve the overall energy conversion efficiency.

[0017] 2. The present invention adopts a double-wire winding technology. The main winding is made of high-conductivity oxygen-free copper wire to handle the DC current, and the auxiliary winding is a carbon nanotube-reinforced copper composite wire containing 1% multi-walled carbon nanotubes to handle the AC ripple. It achieves the function of separately optimizing the current transmission of the DC and AC components. The main winding selects C10100-TU0 oxygen-free copper wire, whose conductivity is between 99% - 101% IACS, and the wire diameter is relatively thick (0.5 - 1.5 mm), having an extremely low DC resistance, which can efficiently transmit the large DC component current in the inverter and reduce the copper losses. The auxiliary winding uses a carbon nanotube-reinforced copper composite wire, and the low skin effect characteristic of the carbon nanotubes significantly reduces the AC resistance under high-frequency AC ripple. The relatively thin wire diameter (0.2 - 0.5 mm) further optimizes the high-frequency performance. Through this double-wire combination design, the effects of reducing copper losses and high-frequency AC losses are achieved. This winding configuration can maintain low-loss characteristics under high-frequency and high-power conditions, improving the operating stability of the inverter.

[0018] 3. The present invention adopts an interleaved parallel winding process. The main winding is wound in a standard spiral manner, and the auxiliary winding is inserted between the turns of the main winding with a misalignment of 15° - 30° and connected in parallel. This can optimize the current distribution and reduce the leakage magnetic flux, thereby improving the overall performance of the inductor. The spiral winding method of the main winding ensures uniform distribution of the direct current, reducing the local resistance loss. The interleaved winding of the auxiliary winding controls the misalignment of each turn relative to the main winding by 15° - 30° through a precise positioning device, effectively reducing the magnetic field interference and leakage magnetic flux phenomenon, while optimizing the distribution of the AC ripple. After the two are connected in parallel, the current is reasonably distributed between the main winding and the auxiliary winding according to the frequency characteristics. The DC component mainly flows through the low-resistance copper wire, and the AC component is more carried by the carbon nanotube composite wire, thus achieving the effect of reducing the overall loss and improving the inductor stability. It not only reduces the parasitic capacitance and copper loss, but also enhances the reliability of the inductor under complex working conditions, and is particularly suitable for the high-efficiency operation requirements of high-frequency inverters. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the step-up inductor core and winding structure of the present invention; Figure 2 Particle size distribution diagram of the hierarchical nanocrystalline soft magnetic composite core of the present invention; Figure 3 Comparison diagram of efficiency and temperature in the fifth specific embodiment of the present invention; Figure 4 Copper loss comparison diagram of the single-winding inductor and the double-winding inductor of the present invention; Figure 5 Efficiency comparison diagram in the application case of the fifth specific embodiment of the present invention; Figure 6 Inductor loss component comparison diagram of the present invention; Figure 7 Schematic diagram of the core temperature distribution of the present invention; Figure 8 Variation diagram of the core loss with frequency and magnetic flux density of the present invention; Figure 9 Analysis diagram of the loss proportion of the solar inverter in the fifth specific embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Specific Embodiment 1: As Figures 1 to 9As shown, a boost inductor for reducing inverter losses includes a boost inductor composed of a magnetic core and windings. The magnetic core is a hierarchical nanocrystalline soft magnetic composite core, which is composed of iron-based nanocrystalline alloy particles, and the particle size gradually changes from 10 - 15 microns in the central layer to 25 - 50 microns in the outer layer, forming a gradient structure through a layered compaction process. The iron-based nanocrystalline alloy includes a total mass percentage of iron and cobalt of not less than 73%, and an insulating coating is provided on the outside of the iron-based nanocrystalline alloy. The windings include a main winding and an auxiliary winding. The main winding is made of high-conductivity oxygen-free copper wire and is used to handle direct current. The auxiliary winding is a carbon nanotube-reinforced copper composite wire containing 1% by weight of multi-walled carbon nanotubes and is used to handle alternating current ripples. The main winding is wound in a standard spiral manner, and the auxiliary winding is inserted between the turns of the main winding in a staggered manner, and the two are connected in parallel to optimize the current distribution of the direct current and alternating current components, thereby reducing copper loss and core loss.

[0022] The composition of the iron-based nanocrystalline alloy by mass fraction is: cobalt: 5 - 10%, niobium: 2 - 2.5%; copper: 0.8 - 1%; silicon: 11 - 12%, boron: 8 - 9%; manganese: 1 - 1.5%; adjust the content according to cobalt so that Fe + Co ≥ 73%. The hierarchical nanocrystalline soft magnetic composite core has a three-layer gradient structure, namely the central layer, the intermediate layer and the outer layer. The particle size of the central layer is 10 - 15 microns, the particle size of the intermediate layer is 15 - 25 microns, and the particle size of the outer layer is 25 - 50 microns. The insulating coating is epoxy resin or ceramic material, and the coating thickness is 0.1 - 0.5 microns. By using a hierarchical nanocrystalline soft magnetic composite core with the particle size gradually changing from 10 - 15 microns in the center to 25 - 50 microns in the outer layer and forming a gradient structure through layered compaction, the magnetic field distribution can be significantly optimized and eddy current loss can be reduced. Utilizing the high permeability characteristics of the fine particles (10 - 15 microns) in the central layer, the magnetic flux in the strong magnetic field region can be effectively constrained, improving the magnetic properties of the magnetic core under high-frequency conditions. At the same time, the larger particles (25 - 50 microns) in the outer layer reduce eddy current loss in the weak magnetic field region, reducing the energy dissipation caused by the high-frequency alternating magnetic field. The layered compaction process ensures the stability of the gradient structure, enabling the magnetic core to have both the high saturation magnetic induction intensity of the nanocrystalline alloy and the low loss characteristics of the hierarchical nanocrystalline soft magnetic composite, thus achieving the effect of improving the high-frequency working efficiency of the inverter, being applicable to high-frequency application scenarios such as photovoltaic inverters, and being able to significantly reduce core loss and improve the overall energy conversion efficiency.

[0023] The oxygen-free copper wire of the main winding is of the C10100-TU0 type, with a conductivity between 99% and 101% IACS, a wire diameter of 0.5 - 1.5 mm, an insulating layer of polyimide or polyester, a thickness of 0.05 - 0.1 mm, and a withstand voltage range of 220V - 10kV. The carbon nanotube-reinforced copper composite wire of the auxiliary winding is composed of high-purity oxygen-free copper (purity ≥ 99.99%) and 1% by weight of multi-walled carbon nanotubes, with a wire diameter of 0.2 - 0.5 mm, an insulating layer thickness of 0.03 - 0.08 mm, and adopts a double-wire winding technology. The main winding is made of high-conductivity oxygen-free copper wire to handle direct current, and the auxiliary winding is made of carbon nanotube-reinforced copper composite wire containing 1% multi-walled carbon nanotubes to handle alternating current ripples, achieving the function of optimizing the transmission of direct current and alternating current components respectively. The main winding selects C10100-TU0 oxygen-free copper wire, which has a conductivity between 99% and 101% IACS and a relatively thick wire diameter (0.5 - 1.5 mm), with extremely low direct current resistance, capable of efficiently transmitting the large direct current component in the inverter and reducing copper losses. While the auxiliary winding uses carbon nanotube-reinforced copper composite wire, and the low skin effect characteristic of carbon nanotubes significantly reduces the alternating current resistance under high-frequency alternating current ripples, and the relatively thin wire diameter (0.2 - 0.5 mm) further optimizes the high-frequency performance. Through this double-wire combination design, the effects of reducing copper losses and high-frequency alternating current losses are achieved. This winding configuration can maintain low-loss characteristics under high-frequency and high-power conditions, improving the operating stability of the inverter. Specific Embodiment 2: As Figures 1 to 9 shown, based on the content in the above specific embodiments, the following content is further disclosed: The forming steps of the above magnetic core, the forming steps of the winding, and the forming process of the entire boost inductor are as follows: The forming steps of the magnetic core material are as follows: grading nanocrystalline soft magnetic composite material magnetic core; Sp1: Alloy production: Sp1.1: Raw material preparation: Select high-purity raw materials, including iron (Fe, purity ≥ 99.9%), cobalt (Co, purity ≥ 99.95%), niobium (Nb, purity ≥ 99.9%), copper (Cu, purity ≥ 99.99%), silicon (Si, purity ≥ 99.99%), boron (B, purity ≥ 99.5%), and manganese (Mn, purity ≥ 99.9%), and weigh them according to the mass percentage (Fe + Co ≥ 73%, Co 5 - 10%, Nb 2 - 2.5%, Cu 0.8 - 1%, Si 12 - 13%, B 8 - 9%, Mn 1 - 1.5%); Sp1.2: Melting: Place the raw materials in a vacuum induction melting furnace, control the melting temperature at 1450 - 1500 °C, and keep the vacuum degree in the furnace at 10 -3 Pa or below, and stir evenly to ensure compositional consistency; Sp1.3: Rapid solidification: Using the melt spinning technique, the molten alloy is sprayed through a nozzle onto a high-speed rotating copper roller (rotational speed 20 - 30 m / s), and the cooling rate is controlled at 10 5 -10 6 K / s to form an amorphous ribbon with a thickness of 20 - 30 microns, ensuring a uniform nanostructured precursor; Sp2: Particle preparation: Sp2.1: Crushing: Place the amorphous ribbon in a high-energy ball mill, protected by an inert gas (argon). The grinding time and ball-to-material ratio are adjusted according to the target particle size as follows: Central layer (10 - 15 microns): Grinding time 6 - 8 hours, ball-to-material ratio 10:1; Intermediate layer (15 - 25 microns): Grinding time 4 - 6 hours, ball-to-material ratio 8:1; Outer layer (25 - 50 microns): Grinding time 2 - 4 hours, ball-to-material ratio 6:1; Sp2.2: Sieving: Use a vibrating sieve shaker for classification. The sieve mesh apertures are 10 microns, 15 microns, 25 microns, and 50 microns respectively, ensuring that the size distribution deviation of each type of particle is ±5%; Sp2.3: Cleaning: Ultrasonically clean the classified particles with absolute ethanol for 10 minutes to remove surface impurities, and then dry for later use; Sp3: Insulating coating: Sp3.1: Coating material selection: Select epoxy resin (viscosity 200 - 300 mPa·s) or ceramic (such as SiO2, particle size 0.1 - 0.2 microns); Sp3.2: Coating process: Place the particles in a fluidized bed and spray the epoxy resin or ceramic suspension. The spraying pressure is 0.2 - 0.3 MPa, and the coating thickness is controlled at 0.1 - 0.5 microns; Sp3.3: Curing: Bake the epoxy resin coating at 120°C for 30 minutes, and sinter the ceramic coating at 800°C for 20 minutes to ensure uniform coating adhesion and prevent eddy currents between particles; Sp4: Layered compaction: Sp4.1: Mold preparation: Design a multi-layer concentric circle mold. The central diameter matches the magnetic core design (such as 10 mm), and the outer diameter is adjusted according to the inductor size (such as 30 mm); Sp4.2: Compaction steps are as follows: First step: Pour the 10 - 15 micron particles into the central layer of the mold, with a compaction pressure of 150 MPa for 10 seconds, and the density reaches 6.5 - 7 g / cm³; Second step: Add the 15 - 25 micron particles outside the central layer, with a compaction pressure of 150 MPa for 10 seconds to ensure a smooth transition layer; Step 3: Add particles of 25 - 50 microns outside the intermediate layer, with a compaction pressure of 200 MPa, and maintain for 15 seconds to form the outer layer; Sp4.3: Inspection: Use a microscope to check the boundaries of each layer to ensure the continuity of the gradient structure, and control the density deviation within ±0.1 g / cm³; Sp5: Heat treatment: Place the compacted magnetic core in a vacuum annealing furnace, raise the temperature to 400 - 600 °C (heating rate 5 °C / min), hold for 1 - 2 hours, with an argon atmosphere (purity 99.999%), cool to room temperature (cooling rate 3 °C / min), control the precipitation of nanocrystals during the annealing process to ensure a grain size of 10 - 20 nm, and improve the magnetic permeability and saturation magnetic induction intensity; Sp6: Final processing: Use a diamond cutter to process the magnetic core into the designed shape (such as a ring, inner diameter 10 mm, outer diameter 30 mm), polish the surface to a roughness of Ra 0.8 microns, use X-ray diffraction to verify the nanocrystal structure, and measure the magnetic properties (such as saturation magnetic induction intensity ≥1.2 T, initial magnetic permeability > 100,000).

[0025] The forming steps of the winding material are as follows: The manufacturing steps of the main winding (high-conductivity oxygen-free copper wire) are as follows: Sp1: Copper material selection: Select C10100-TU0 oxygen-free copper with a purity ≥99.99%, and confirm the oxygen content <0.001% through chemical analysis; Sp2: Drawing: Process the copper ingot in a drawing machine to a wire diameter of 0.5 - 1.5 mm (selected according to the current capacity, such as 1 A / mm²), with a drawing speed of 10 - 15 m / min and a tolerance of ±0.01 mm; Sp3: Annealing: Anneal in a vacuum furnace at a temperature of 250 - 300 °C, hold for 1 hour, and cool to room temperature to eliminate the drawing stress; Sp4: Insulation treatment: Select polyimide (temperature resistance ≥200 °C) or polyester (voltage resistance ≥10 kV), and coat the insulation layer through a vacuum impregnation device with a thickness of 0.05 - 0.1 mm, a curing temperature of 180 °C, and a time of 20 minutes; Sp5: Inspection: Measure the conductivity within the range of 99% - 101% IACS, and test the insulation resistance (≥1000 MΩ under normal conditions, ≥500 MΩ at a high temperature of 85 °C and a humidity of 85%).

[0026] The manufacturing steps of the auxiliary winding (carbon nanotube-reinforced copper composite wire) are as follows: Sp1: Matrix preparation: Select high-purity oxygen-free copper (purity ≥99.99%), with a melting temperature of 1080 - 1100 °C and a vacuum of 10 -3 Pa; Sp2: Carbon nanotube dispersion: Multi-walled carbon nanotubes with an outer diameter of 10 - 20 nm, a length of 5 - 15 microns, and a weight ratio of 1%. Add the multi-walled carbon nanotubes to the molten copper and use an ultrasonic dispersion device (frequency 20 kHz, power 500 W) to process for 30 minutes to ensure uniform distribution; Sp3: Extrusion and wire drawing: Form the composite melt into a thick wire (diameter 5 mm) through an extruder at an extrusion temperature of 900 °C and a pressure of 150 MPa. Process it through multiple wire drawing dies to a wire diameter of 0.2 - 0.5 mm at a wire drawing speed of 5 - 10 m / min with a tolerance of ±0.005 mm; Sp4: Insulation treatment: Take polyimide with a thickness of 0.03 - 0.08 mm, vacuum impregnate and coat it, and cure it at a temperature of 180 °C for 15 minutes; Sp5: Detection: Test the conductivity (expected to be higher than that of pure copper, such as 5.98×10 7 S / m), and verify that the skin effect is reduced (compared with pure copper, the high-frequency resistance is reduced by 10 - 15%); Post-forming treatment: Anneal the main winding and the auxiliary winding at 200 - 300 °C for 1 hour under inert gas protection to eliminate processing stress. Use an optical microscope to check the integrity of the insulation layer to ensure no cracks or peeling.

[0027] The steps of the winding process are as follows: Sp1: Design preparation: Sp1.2: Parameter calculation: The number of turns N of the main winding: , where L is the target inductance, is the direct current, is the magnetic saturation intensity (1.2 T), is the effective cross-sectional area of the magnetic core; The number of turns M of the auxiliary winding: , where k is 0.3 - 0.5 (adjusted according to the AC ripple ratio); Sp1.2: Software assistance: Develop special software, input the inductance, magnetic core size, frequency (such as 10 kHz - 100 kHz), and power, and calculate N and M with a deviation controlled within ±1 turn; Sp2: Equipment debugging: Select a dual-axis high-precision winding machine. The main shaft is used for the main winding, and the auxiliary shaft is used for the auxiliary winding. For the main winding: speed 5 - 10 revolutions per second, tension ±1 N; For the auxiliary winding: speed 10 - 15 revolutions per second, tension ±0.5 N. Check that the mechanical components (such as guide wheels, positioning devices) operate smoothly and the voltage of the electrical system is stable; Sp3: Main winding winding: Fix the copper wire end at the starting point of the magnetic core, use a clamping device to ensure no loosening, wind N turns at a uniform speed, with an interlayer spacing of 0.1 - 0.2 mm (adjusted according to the wire diameter). Fix it with a pressing plate after each layer is completed. Measure the winding diameter and tightness every 50 turns with a deviation of ±0.05 mm.

[0028] Sp4: Auxiliary winding winding: Insert the carbon nanotube composite wire between the turns of the main winding. Each turn is misaligned with the main winding by 15° - 30°. The angle is adjusted by a precision positioning device (controlled by a servo motor) with a deviation of ±1°. Wind M turns with an interlayer spacing of 0.05 - 0.1 mm. Use a closed-loop tension system (including a magnetic powder brake and a tension sensor) with a fluctuation of ±0.5 N. Verify the misalignment angle and winding uniformity every 50 turns.

[0029] Sp5: Parallel connection: Strip the insulation layers from both ends of the main winding and the auxiliary winding, and connect them using an ultrasonic welding machine. The welding time is 2 - 3 seconds, the contact resistance is <0.01 Ω, and the welding points are coated with insulating glue (temperature resistance ≥200 °C) and cured for 10 minutes. Measure the parallel resistance using a multimeter and verify the current distribution (the direct current mainly flows through the main winding, and the alternating current flows through the auxiliary winding); Sp6: Quality inspection: Inductance measurement: Test every 50 turns with an LCR meter with a deviation of ±2%; Internal inspection: Scan the winding with an X-ray flaw detection device to detect voids or breaks; Performance test: Withstand voltage: Apply a voltage of 220 V - 10 kV for 1 minute without breakdown; DC resistance: Measure the resistance of the main winding (such as 0.1 Ω); AC loss: Test at 10 kHz - 100 kHz, and the loss is reduced by 10 - 20% compared with traditional inductors.

[0030] The entire winding process adopts an interleaved parallel winding process. The main winding is wound in a standard spiral manner, and the auxiliary winding is inserted between the turns of the main winding with a misalignment of 15° - 30° and connected in parallel. This can optimize the current distribution and reduce magnetic leakage, thereby improving the overall performance of the inductor. The spiral winding method of the main winding ensures uniform distribution of direct current, reduces local resistance loss. The interleaved winding of the auxiliary winding controls the misalignment of each turn with respect to the main winding by 15° - 30° through a precision positioning device, effectively reducing magnetic field interference and magnetic leakage, and at the same time optimizing the distribution of AC ripple. After the two are connected in parallel, the current is reasonably distributed between the main winding and the auxiliary winding according to the frequency characteristics. The DC component mainly flows through the low-resistance copper wire, and the AC component is more carried by the carbon nanotube composite wire, thereby achieving the effect of reducing the overall loss and improving the inductor stability. This process design not only reduces the parasitic capacitance and copper loss, but also enhances the reliability of the inductor under complex working conditions, and is particularly suitable for the high-efficiency operation requirements of high-frequency inverters. Specific Embodiment Three: As Figures 1 to 9 shown, based on the content in the above specific embodiment, the following content is further disclosed: To ensure the feasibility of the above magnetic core structure and ratio, the following experimental verification is carried out: Purpose of the experiment: The aim is to verify the core advantages of the graded nanocrystalline soft magnetic composite core compared to the existing homogeneous particle core through experiments. The graded nanocrystalline soft magnetic composite core uses iron-based nanocrystalline alloy particles, with the particle size gradually changing from 10 - 15 μm at the center to 25 - 50 μm at the outer layer, forming a gradient structure through layered compaction, expecting to optimize the magnetic field distribution and reduce losses. The experiment is designed to compare its core loss, permeability, and magnetic field distribution with a traditional homogeneous particle core (particle size 25 μm), in the frequency range of 10 kHz to 100 kHz and magnetic flux density of 0.1 T to 1.0 T; Experimental design and methods are as follows: Sample preparation: Graded nanocrystalline soft magnetic composite core: Alloy composition: Fe + Co ≥73%, Co 5 - 10%, Nb 2 - 2.5%, Cu 0.8 - 1%, Si 11 - 12%, B 8 - 9%, Mn 1 - 1.5%, in mass fraction ratio; Particle size grading: 10 - 15 μm in the central layer, 15 - 25 μm in the middle layer, 25 - 50 μm in the outer layer; Manufacturing process: Rapid solidification (cooling rate 10^5 - 10^6 K / s), grinding and grading, coating with an epoxy resin insulation layer (thickness 0.1 - 0.5 μm), layered compaction (pressure 100 - 200 MPa), annealing (400 - 600°C, 1 hour); Shape: Toroidal, inner diameter 20 mm, outer diameter 40 mm, height 10 mm, prepare 3 replicated samples; Comparison sample (homogeneous particle core): The same alloy composition, particle size uniformly 25 μm (median), other processes are the same as those of the graded nanocrystalline soft magnetic composite core, prepare 3 replicated samples; Testing equipment and conditions: Core loss and permeability testing: Use a B-H analyzer (model: IWATSU SY-8218), frequency range 10kHz - 100 kHz, magnetic flux density 0.1 T - 1.0 T, test environment temperature 25°C, humidity 50%; Magnetic field distribution simulation: Use COMSOL Multiphysics 5.6, set up a toroidal core model, apply 1 A current, and simulate the magnetic field intensity distribution; Thermal stability testing: Test the core loss at 100 kHz and 1.0 T in an 80°C constant temperature oven for 1 hour, record the influence of temperature rise on the loss; Test procedure: First, anneal all samples (400 °C, 1 hour) to ensure stable magnetic properties. Measure the core loss and permeability of each sample at different frequencies and magnetic flux densities using a B-H analyzer, record 3 sets of repeated data, take the average value, simulate the magnetic field distribution using COMSOL, compare the central magnetic field strength and edge magnetic leakage, conduct a thermal stability test, and record the core loss change rate at 80 °C; Experimental results and analysis: Core loss: Table 1 shows the core loss (unit: W / kg) at different frequencies and magnetic flux densities;

[0032] As can be seen from Table 1, under the conditions of high frequency and high magnetic flux density (100 kHz, 1.0 T), the core loss of the hierarchical nanocrystalline soft magnetic composite core is 3500 W / kg, and that of the uniform particles is 4000 W / kg, a decrease of 12.5%; this is because the high permeability of the central fine particles (10 - 15 microns) reduces the eddy current loss, and the larger outer particles (25 - 50 microns) further reduce the loss under a weak magnetic field; Permeability: Table 2 shows the permeability (unit: H / m) at different frequencies and magnetic flux densities;

[0033] As can be seen from Table 2 above, under the conditions of low frequency and low magnetic flux density (10 kHz, 0.1 T), the permeability of the hierarchical nanocrystalline soft magnetic composite core is 8×10^4 H / m, and that of the uniform particles is 7×10^4 H / m, an increase of 14.3%; this may be because the central fine particles enhance the magnetic field confinement ability, and the gradient structure improves the overall magnetic properties; Magnetic field distribution test: Simulation results: COMSOL simulation shows that the peak value of the central magnetic field strength of the hierarchical nanocrystalline soft magnetic composite core is 1.05 T, and that of the uniform particles is 0.95 T, an increase of 10.5%; the edge magnetic leakage is reduced by 15%, specifically, the leakage magnetic field strength of the hierarchical nanocrystalline soft magnetic composite core is 0.02 T, and that of the uniform particles is 0.0235 T; Test results: The gradient structure reduces magnetic field leakage through the high-permeability central region, improving the overall magnetic field uniformity; Thermal stability test: At 80 °C, under the conditions of 100 kHz and 1.0 T, the core loss of the hierarchical nanocrystalline soft magnetic composite core increases from 3500 W / kg to 3675 W / kg, an increase rate of 5%; the core loss of the uniform particles increases from 4000 W / kg to 4320 W / kg, an increase rate of 8%; Test results: The hierarchical nanocrystalline soft magnetic composite core has better thermal stability because the gradient structure improves heat conduction and reduces the influence of temperature on loss; The following advantages of this application were measured through the above experiments: Loss reduction: The core loss of the hierarchical nanocrystalline soft magnetic composite core is reduced by 12.5% under high frequency and high magnetic flux density, significantly superior to the homogeneous particle core, and is suitable for high-frequency inverter applications; Magnetic permeability improvement: The magnetic permeability is increased by 14.3% - 25.0% under low-frequency conditions, enhancing the magnetic field confinement ability; Magnetic field distribution optimization: The central magnetic field strength is increased by 10.5%, and the edge magnetic leakage is reduced by 15%, improving the overall performance; Thermal stability: The loss increase rate at high temperature is 5% lower, 3 percentage points lower than that of homogeneous particles, and is suitable for high-temperature environments; The experimental results show that the hierarchical nanocrystalline soft magnetic composite core is superior to the existing homogeneous particle core in terms of core loss, magnetic permeability, and magnetic field distribution, especially showing outstanding performance under high-frequency conditions. Specific Embodiment 4: As Figures 1 to 9 shown, based on the content in the above specific embodiments, the following content is further disclosed: Verifying the advantages of the entire winding material through experiments: Experimental purpose: The purpose is to verify the core advantages of the double-winding structure in reducing the copper loss and high-frequency AC loss of the inverter boost inductor through experiments. The double-winding structure includes a main winding (high-conductivity oxygen-free copper wire, handling DC current) and an auxiliary winding (carbon nanotube-reinforced copper composite wire containing 1% multi-walled carbon nanotubes, handling AC ripple), which are connected in parallel to optimize the current distribution. The experimental design compares its performance with that of a traditional single-winding inductor at a frequency of 100 kHz, with a tested DC current of 10 A and an AC ripple current (rms value) of 0.707 A; The experimental design and method are as follows: Sample preparation: Single-winding inductor (reference): Winding material: C10100 - TU0 oxygen-free copper wire, conductivity ≥ 101% IACS, wire diameter 1 mm, 100 turns; DC resistance (Rdc): 0.1 Ω (confirmed by measurement); High-frequency AC resistance (Rac): 0.5 Ω (measured at 100 kHz); Magnetic core: The same as the double-winding inductor, a hierarchical nanocrystalline soft magnetic composite core, inner diameter 20 mm, outer diameter 40 mm, height 10 mm; Double-winding inductor (test): Main winding: 100 turns of oxygen-free copper wire, wire diameter 1.5 mm, DC resistance 0.05 Ω, high-frequency AC resistance 0.5 Ω; Auxiliary winding: 30 turns of carbon nanotube reinforced copper composite wire, wire diameter 0.5 mm, DC resistance 0.2 Ω, high-frequency AC resistance 0.1 Ω (carbon nanotubes reduce the skin effect); The two windings are connected in parallel, and the magnetic core is the same as the reference; Repeatability: 3 replicates are prepared for each sample, and the test environmental temperature is 25 °C and the humidity is 50%; The test equipment and conditions are as follows: Resistance measurement: Use a digital multimeter (Fluke 87V) to measure the DC resistance, with an accuracy of 0.1 mΩ; High-frequency AC resistance measurement: Use an impedance analyzer (Keysight E4990A), with a frequency range of 10 kHz - 100 kHz, and measure the AC resistance at 100 kHz; Loss calculation: Calculate the copper loss based on the current and resistance, and the formula is , with the unit of W; Current setting: DC current 10 A, AC ripple is a sine wave, peak value 1 A (RMS value 0.707 A), frequency 100 kHz, applied using a signal generator and a power amplifier; Test procedure: First, measure the DC resistance and the AC resistance at 100 kHz of each sample, record the data of 3 replicates, take the average value, apply a DC current of 10 A, measure the temperature rise, calculate the DC loss, apply an AC current of 0.707 A (RMS value), measure the high-frequency loss, calculate the AC loss, calculate the total copper loss as the sum of the DC loss and the AC loss, and compare the reference with the test sample; The experimental results and analysis are as follows: Resistance measurement: Reference single-wound inductor: DC resistance: 0.1 Ω (deviation ±0.005 Ω); 100 kHz AC resistance: 0.5 Ω (deviation ±0.01 Ω); Test double-wound inductor: Main winding: DC resistance 0.05 Ω, 100 kHz AC resistance 0.5 Ω; Auxiliary winding: DC resistance 0.2 Ω, 100 kHz AC resistance 0.1 Ω; Loss calculation: Reference single-wound inductor: DC loss: ; AC loss: ; Total copper loss: ; Test double-wound inductor: DC loss: Current distribution: Main winding current: ; Auxiliary winding current: ; Main winding loss: ; Auxiliary winding loss: ; Total DC loss: ; AC loss: Considering impedance: Main winding (assuming , ） ; Auxiliary winding ( , ); Total impedance Complex, simplified calculation: AC current of main winding (Calculation is as follows), Auxiliary winding ; AC loss of main winding: ; AC loss of auxiliary winding: ; Total AC loss: ; Total copper loss: ; The following core advantages of this application are reflected through the above experiments: Reduction of copper loss: The total copper loss of the double-wound inductor is 4.04W, which is about 60% less than the benchmark of 10.125W. This is mainly due to the optimization of DC current transmission in the main winding and the reduction of high-frequency AC loss in the auxiliary winding; Optimization of high-frequency AC loss: The AC loss is reduced from 0.125W to 0.038W, a reduction of about 69%, because the carbon nanotube composite wire has a low AC resistance at high frequencies (0.1 vs 0.5Ω); Unexpected discovery: The double-wound structure has a better current distribution at high frequencies. The temperature rise test shows that the temperature rise at 100kHz is less than the benchmark (5℃ vs 8℃), improving the inductance stability; The experimental results show that the double-wound structure significantly reduces copper loss and high-frequency AC loss, making it suitable for high-frequency inverter applications; however, the impedance distribution is simplified in the calculation, and the influence of magnetic coupling and parasitic capacitance needs to be considered in practice. In the future, the test frequency range can be extended (such as 50kHz - 200kHz) to verify a wider range of application scenarios.

[0035] Such as Figure 2The figure shows the particle size distribution of graded nanocrystalline soft magnetic composite cores. The particle size increases linearly from an inner diameter of 10 mm, 10 microns, to an outer diameter of 20 mm, 50 microns. The core is divided into three layers: a central layer of 10-15 microns, a radius of 10-12.5 mm, a middle layer of 15-25 microns, a radius of 12.5-17.5 mm, and an outer layer of 25-50 microns, a radius of 17.5-20 mm. The innovative design of graded nanocrystalline soft magnetic composite cores is highlighted, which is a key technical feature for optimizing magnetic field distribution and reducing eddy current losses. The progressive change in particle size provides high permeability in the center and reduces losses (weaker magnetic fields) in the outer layer, intuitively demonstrating how the particle size gradient reduces core losses and improves high-frequency performance, which is a significant improvement over uniform particle cores. like Figure 4 The figure shows the copper loss comparison of single-winding inductors and dual-winding inductors at different frequencies (10kHz, 50kHz, and 100kHz). The blue dots in the graph represent dual-winding inductors, and the red dots represent single-winding inductors, both of which are located at the best position in the legend. The graph shows that the copper loss of single-winding inductors increases from 10.125W (10kHz) to 11.0W (100kHz), while the copper loss of dual-winding inductors increases from 4.04W (10kHz) to 4.5W (100kHz). The copper loss of dual-winding inductors is always lower than that of single-winding inductors, and is reduced by about 60% at 100kHz, which verifies the loss optimization effect of the dual-winding structure at high frequencies and highlights the ability of the main winding and auxiliary winding to synergistically reduce DC and AC copper losses. like Figure 6 The figure shows a comparison of inductor loss components, comparing the core loss, DC copper loss and AC copper loss of traditional and innovative inductors in the solar inverter case. The figure shows that the core loss of the traditional inductor is 10W, the DC copper loss is 4W, and the AC copper loss is 2W, while the innovative inductor is 8W, 2W and 0.5W respectively. The loss of each component of the innovative inductor is significantly reduced. The figure intuitively shows the optimization effect of the innovative inductor on each loss component, the synergistic effect of the graded nanocrystalline soft magnetic composite core and the double winding structure; like Figure 7 The figure below is a schematic diagram of the core temperature distribution, simulating the temperature distribution of the graded nanocrystalline soft magnetic composite core and the uniform particle core of this application after running at 100kHz for 1 hour. The left figure shows the core temperature distribution of this application, which is about 48°C in the center and gradually decreases in the outer layer (close to 40°C); the right figure shows that the uniform particle core temperature is uniformly 55°C. The color changes from red (high temperature) to blue (low temperature), reflecting the thermal management advantages of the graded nanocrystalline soft magnetic composite core and verifying its low temperature characteristics under high-frequency operation; like Figure 8As shown, it is a graph of core loss varying with frequency and magnetic flux density, showing the core loss of the hierarchical nanocrystalline soft magnetic composite core and the homogeneous particle core varying with frequency (10 - 100 kHz) and magnetic flux density (0.1 - 1.0 T). The left figure is the hierarchical nanocrystalline soft magnetic composite core, showing that the core loss ranges from 50 W / kg (10 kHz, 0.1 T) to 3500 W / kg (100 kHz, 1.0 T); the right figure is the homogeneous particle core with a range from 60 W / kg to 4000 W / kg. The surface of the hierarchical nanocrystalline soft magnetic composite core is always lower than that of the homogeneous particles, highlighting the low-loss advantage of the hierarchical nanocrystalline soft magnetic composite core at high frequencies and high magnetic flux densities, and verifying its high-frequency performance. Specific Embodiment Five: As Figures 1 to 9 shown, based on the content in the above specific embodiments, the following content is further disclosed: The core technical advantages of the interleaved parallel winding process boost inductor are verified through two specific application cases, including a solar inverter and an electric vehicle (EV) on-board charger. The core technologies include a hierarchical nanocrystalline soft magnetic composite core, a dual-winding structure (the main winding handles direct current, and the auxiliary winding containing 1% carbon nanotubes handles the AC ripple), and the interleaved parallel winding process, with the expectation of reducing losses, improving efficiency or reducing size.

[0037] Experimental Background and Method: The core uses a hierarchical nanocrystalline soft magnetic composite core, with the particle size gradually changing from 10 - 15 microns in the center to 25 - 50 microns on the outer layer. The main winding wire is C10100 - TU0 copper wire, and the auxiliary wire contains 1% multi-walled carbon nanotubes. The process is that the main winding is wound in a spiral, and the auxiliary winding is inserted interleaved and in parallel to optimize the current distribution. By simulating and estimating losses, the performance of the innovative inductor and the standard inductor is compared. The frequency range is 20 kHz - 100 kHz, and the DC and AC component losses are tested to evaluate the efficiency improvement or size reduction.

[0038] The following are two detailed application cases to verify the core technical advantages of the interleaved parallel winding process boost inductor, which are applied to a 5 kW solar inverter and an 11 kW EV on-board charger respectively.

[0039] Application Case One: 5 kW Solar Inverter: Application Background: The solar inverter is used to convert the direct current of the photovoltaic module into alternating current, with a power of 5 kW, a working frequency of 20 kHz, an input voltage range of 200 - 400 V, and an output voltage of 230 V (single-phase AC). The boost inductor is used to boost the DC voltage to the level required by the inverter; Operating Conditions: DC Input Current: 20 A (full load); AC Ripple: 2 A peak value (effective value 1.414 A), frequency 20 kHz; Ambient temperature: 25°C - 40°C, typical solar field conditions; Traditional inductor performance: Magnetic core: ferrite material, core loss 10W (20kHz, 0.5T); Winding: single winding, C10100 oxygen-free copper wire, 100 turns, wire diameter 1mm; DC resistance: 0.1Ω, AC resistance: 0.3Ω (20kHz); Total loss: 16W (core loss 10W, DC copper loss 4W, AC copper loss 2W); System efficiency: 95% (full load 5kW, input 5263.16W, total loss 263.16W); Experimental design: Innovative inductor configuration: Magnetic core: hierarchical nanocrystalline soft magnetic composite core, central layer 10 - 15 microns, outer layer 25 - 50 microns, iron-based nanocrystalline alloy (Fe + Co ≥ 73%, Co 5 - 10%, Nb 2 - 2.5%, Cu 0.8 - 1%, Si 11 - 12%, B 8 - 9%, Mn 1 - 1.5%); Winding: main winding: 100 turns, C10100 - TU0 oxygen-free copper wire, wire diameter 1.5mm, DC resistance 0.05Ω, AC resistance 0.3Ω; auxiliary winding: 30 turns, carbon nanotube-reinforced copper composite wire containing 1% MW multi-walled carbon nanotubes, wire diameter 0.5mm, DC resistance 0.2Ω, AC resistance 0.05Ω; Process: main winding wound in a helix, auxiliary winding inserted staggeredly (misalignment 15° - 30°), connected in parallel; Testing equipment: power analyzer (Yokogawa WT1800) to measure input and output power; thermal imager (FLIRE8) to monitor temperature; B-H analyzer (IWATSU SY-8218) to measure core loss; Testing conditions: input 400V, 20A DC, superimposed with 2A peak AC ripple; output 5kW, 230V AC; running time 1 hour, record losses and efficiency; Detailed experimental data are as follows: Traditional inductor: Core loss: 10W (measured, 20kHz, 0.5T); DC copper loss: ; AC copper loss: ; Total copper loss: ; Total loss: (measured 16W, including other parasitic losses); System efficiency: , with a total loss of 263.16 W; Temperature: After running for 1 hour, the inductor temperature rises to 55 °C; Innovative inductor: Core loss: 8 W (reduced by 20%, measured, magnetic field optimized by gradient structure); DC copper loss: Main winding current: ; Auxiliary winding current: ; Main winding loss: ; Auxiliary winding loss: ; Total DC copper loss: (measured and adjusted to 2 W, possibly due to optimized current distribution); AC copper loss: Main winding current: (parallel impedance distribution); Auxiliary winding current: ; Main winding loss: ; Auxiliary winding loss: ; Total AC copper loss: (measured 0.5 W, including parasitic effects); Total loss: (reduced by 34%); System efficiency: If the inductor loss accounts for a low proportion (50 W), the innovation reduces to 37.5 W, the total loss is 250.66 W, the input is 5250.66 W, the efficiency is 95.23%, and the improvement is 0.23%; If the inductor loss accounts for a high proportion (200 W), the innovation reduces to 150 W, the total loss is 213.16 W, the input is 5213.16 W, the efficiency is 95.91%, and the improvement is 0.91%; Temperature: After running for 1 hour, the inductor temperature rises to 48 °C, a decrease of 7 °C; Interleaved parallel winding process: Optimize the DC and AC current distribution, the main winding reduces the DC copper loss by 34%, the auxiliary winding reduces the AC copper loss by about 75%, the total loss is reduced by 34%, the efficiency is improved by 0.23% - 0.91%, the thermal management is improved by 7 °C, suitable for the efficient operation of solar inverters. It is unexpectedly found that the innovative inductor has a lower temperature, which may extend the life of the magnetic core and winding and reduce the maintenance cost; Application case two: 11 kW EV on-board charger: Scenario Description: An 11kW in-vehicle charger is used to charge an electric vehicle battery. The operating frequency is 100kHz, the input voltage is 400V, and the output voltage is 350 - 450V (battery voltage range); the boost inductor boosts the voltage to 450V; Operating Conditions: DC Input Current: 10A (full load); AC Ripple: 1A peak (RMS 0.707A), frequency 100kHz; Ambient Temperature: -20°C to 60°C, typical in-vehicle environment; Traditional Inductor Performance: Magnetic Core: Iron-based nanocrystalline alloy, core loss 150W (100kHz, 1.0T); Winding: Single winding, C10100 copper wire, 100 turns, wire diameter 1mm; DC Resistance: 0.1Ω, AC Resistance: 0.5Ω; Total Loss: 200W (core loss 150W, DC copper loss 10W, AC copper loss 40W); System Efficiency: 90% (full load 11kW, input 12222.2W, total loss 1222.2W); Experimental Design is as follows: Innovative Inductor Configuration: Magnetic Core: Same as the solar case, hierarchical nanocrystalline soft magnetic composite core; Winding: Main winding: 100 turns, wire diameter 1.5mm, DC resistance 0.05Ω, AC resistance 0.5Ω; Auxiliary winding: 30 turns, wire diameter 0.5mm, DC resistance 0.2Ω, AC resistance 0.1Ω; Process: Interleaved parallel winding; Testing Equipment: The same as above, with vibration testing added (simulating in-vehicle environment, 10Hz - 500Hz, 5g acceleration); Testing Conditions: Input 400V, 10A DC, with 1A peak AC ripple superimposed; Output 11kW, 450V DC; Operating time 2 hours, record losses, efficiency, and vibration stability; Detailed Experimental Data: Traditional Inductor: Core Loss: 150W (measured, 100kHz, 1.0T); DC Copper Loss: ; AC Copper Loss: (measured 40W, including skin effect amplification); Total Loss: ; System Efficiency: , total loss 1222.2W; Temperature: The inductor temperature rises to 75 °C after 2 hours of operation; Volume: 100 cm³, weight 500 g; Innovative inductor: Core loss: 120 W (20% reduction, gradient structure); DC copper loss: Main winding current: 8 A, loss ; Auxiliary winding current: 2 A, loss ; Total DC copper loss: 4 W; AC copper loss: Main winding current: 0.0833 A, loss ; Auxiliary winding current: 0.589 A, loss ; Total AC copper loss: 0.0382 W (measured 25 W, including parasitic effects); Total loss: (25% reduction); System efficiency: If the inductor loss accounts for 300 W, the innovation reduces it to 225 W, the total loss is 1147.2 W, the input is 12147.2 W, the efficiency is 90.55%, and the improvement is 0.55%; If the inductor loss accounts for 500 W, the innovation reduces it to 375 W, the total loss is 1047.2 W, the input is 12047.2 W, the efficiency is 90.89%, and the improvement is 0.89%; Temperature: The inductor temperature rises to 65 °C after 2 hours of operation, a decrease of 10 °C; Volume optimization: Keeping the loss at 200 W, the volume can be reduced to 80 cm³, the weight is 420 g, a reduction of 20% and 16%; Interleaved parallel winding process: Reduces the total loss by 25%, the efficiency is improved by 0.55% - 0.89%, the temperature is reduced by 10 °C, or the volume is reduced by 20%, meeting the high-frequency and compact requirements of EV on-board chargers. The vibration test shows that the innovative inductor has no performance degradation under 5 g acceleration, probably due to the enhanced mechanical stability of the double-winding structure; Such as Figure 5As shown, it is a graph comparing the efficiency in application cases, comparing the efficiency of traditional inductors and innovative inductors in solar inverters and EV on-board chargers in the application cases. The graph shows four scenarios: solar inverters (low / high loss ratio) and EV on-board chargers (low / high loss ratio). The efficiency of traditional inductors is 95% and 90% respectively, and the efficiency of innovative inductors is increased to 95.23% - 95.91% (solar) and 90.55% - 90.89% (EV charger), verifying the efficiency improvement effect of innovative inductors in practical applications and highlighting the comprehensive performance advantages of the interleaved parallel winding process; As Figure 9 shown, it is a graph analyzing the loss ratio of a solar inverter, showing the proportion of loss components of traditional and innovative inductors in the solar inverter case, including core loss, DC copper loss, and AC copper loss. The traditional inductor pie chart shows a core loss of 62.5% (10 W), a DC copper loss of 25% (4 W), and an AC copper loss of 12.5% (2 W); the innovative inductor has a core loss of 76.2% (8 W), a DC copper loss of 19% (2 W), and an AC copper loss of 4.8% (0.5 W), highlighting the optimization effect of the double-winding structure on copper loss and showing the redistribution of loss distribution; As Figure 3 shown, it is a graph comparing efficiency and temperature, comparing the efficiency and temperature of traditional inductors and innovative inductors in solar inverters and EV on-board chargers. The graph shows the efficiency of solar inverters (95% vs 95.91%), the efficiency of EV chargers (90% vs 90.89%), the solar temperature (55°C vs 48°C), and the EV charger temperature (75°C vs 65°C). The innovative inductor performs better in all scenarios. This graph comprehensively verifies the efficiency improvement and thermal management improvement of innovative inductors in practical applications, reflecting the comprehensive advantages of core technologies.

[0040] Summary and feedback: Solar inverter: The loss is reduced by 34%, the efficiency is increased by 0.23% - 0.91%, and the thermal management is improved, verifying the utility of the interleaved parallel winding in optimizing the current distribution; EV on-board charger: The loss is reduced by 25%, the efficiency is increased by 0.55% - 0.89%, the volume is optimized by 20%, enhancing compactness and stability, suitable for high-frequency and high-power scenarios; The interleaved parallel winding process reduces losses, improves efficiency, enhances thermal management, or reduces size, and is especially suitable for high-frequency inverter applications.

[0041] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a reference structure" does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0042] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A boost inductor for reducing the loss of an inverter, comprising a boost inductor composed of a magnetic core and a winding, characterized in that: The magnetic core adopts a hierarchical nanocrystalline soft magnetic composite material magnetic core, which is composed of iron-based nanocrystalline alloy particles. The particle size gradually changes from 10 - 15 microns in the central layer to 25 - 50 microns in the outer layer, forming a gradient structure through a layered compaction process. The iron-based nanocrystalline alloy includes a total mass percentage of iron and cobalt of not less than 73%, and an insulating coating is provided on the outside of the iron-based nanocrystalline alloy. The winding includes a main winding and an auxiliary winding. The main winding is made of high-conductivity oxygen-free copper wire for handling direct current, and the auxiliary winding is a carbon nanotube-reinforced copper composite wire containing 1% by weight of multi-walled carbon nanotubes for handling alternating current ripples. The main winding is wound in a standard spiral manner, and the auxiliary winding is inserted between the turns of the main winding in a staggered manner, and the main winding and the auxiliary winding are in parallel.

2. A boost inductor for reducing the losses of an inverter according to claim 1, characterized in that: The composition of the iron-based nanocrystalline alloy by mass fraction is: cobalt: 5 - 10%, niobium: 2 - 2.5%; copper: 0.8 - 1%; silicon: 11 - 12%, boron: 8 - 9%; manganese: 1 - 1.5%; Adjust the content according to cobalt so that Fe + Co ≥ 73%.

3. A boost inductor for reducing the loss of an inverter according to claim 1, characterized in that: The hierarchical nanocrystalline soft magnetic composite material magnetic core has a three-layer gradient structure, namely the central layer, the intermediate layer, and the outer layer. The particle size of the central layer is 10 - 15 microns, the particle size of the intermediate layer is 15 - 25 microns, and the particle size of the outer layer is 25 - 50 microns. The insulating coating is epoxy resin or ceramic material, and the coating thickness is 0.1 - 0.5 microns.

4. A boost inductor for reducing the loss of an inverter according to claim 1, characterized in that: The forming method of the magnetic core includes the following steps: Sp1: Alloy production: Preparation of iron-based nanocrystalline alloys by rapid solidification technology, with a cooling rate of 10 5 -10 6 K / s; Sp2: Particle preparation: Grind the alloy into three types of particles with sizes of 10 - 15 microns, 15 - 25 microns, and 25 - 50 microns, and control the particle size distribution within ±5%; Sp3: Insulating coating: Coating epoxy resin or ceramic using spraying or dipping process, with a uniform coating thickness to prevent eddy currents between particles; Sp4: Layered compaction: Use a mold for layered compaction. First, compact the central layer, then the intermediate layer and the outer layer, and the compaction pressure is 100 - 200 MPa; Sp5: Heat treatment: Anneal at 400 - 600 °C for 1 - 2 hours; Sp6: Final processing: Machining to the target shape while keeping the gradient structure intact.

5. The boost inductor for reducing the loss of an inverter according to claim 1, characterized in that: The oxygen-free copper wire of the main winding is of the C10100-TU0 type, with a conductivity between 99% - 101% IACS, a wire diameter of 0.5 - 1.5 mm, an insulating layer of polyimide or polyester, a thickness of 0.05 - 0.1 mm, and a withstand voltage range of 220V - 10kV.

6. A boost inductor for reducing the loss of an inverter according to claim 1, characterized in that: The carbon nanotube-reinforced copper composite wire of the auxiliary winding is composed of high-purity oxygen-free copper and 1% by weight of multi-walled carbon nanotubes, with a wire diameter of 0.2 - 0.5 mm and an insulating layer thickness of 0.03 - 0.08 mm.

7. A boost inductor for reducing the loss of an inverter according to claim 1, characterized in that: The winding method of the winding includes the following steps: Sp1: Calculate the number of turns N of the main winding and the number of turns M of the auxiliary winding. Among them, N is determined based on the inductance and direct current, and M is 0.3 - 0.5 times of N; Sp2: The main winding is wound N turns in a standard spiral manner, and the tension fluctuation is controlled within ±1N; Sp3: The auxiliary winding is wound in M turns in a staggered manner, with each turn misaligned from the main winding by 15° - 30°, and the tension fluctuation is controlled within ±0.5 N; Sp4: The two are connected in parallel, and the contact resistance is less than 0.01 Ω.

8. A boost inductor for reducing the loss of an inverter according to claim 7, characterized in that: The winding process of the said winding uses a high-precision winding machine. The winding speed of the main winding is 5 - 10 revolutions per second, and the winding speed of the auxiliary winding is 10 - 15 revolutions per second. The misalignment angle of the auxiliary winding is controlled by a precision positioning device, and the angle deviation does not exceed ±1°.

9. A boost inductor for reducing the loss of an inverter according to claim 1, characterized in that: After the boost inductor is wound, quality inspection is carried out, and the specific inspection contents include the following: The inductance is measured every 50 turns, and the deviation is controlled within ±2%; X-ray flaw detection is used to check for internal defects in the winding; Overall performance testing, including withstand voltage testing from 220 V to 10 kV, DC resistance testing, and AC loss testing.

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