An interleaved parallel winding and magnetic integrated structure suitable for high frequency transformer

Abstract

The application discloses a staggered parallel winding and magnetic integrated structure suitable for a high-frequency transformer and belongs to the technical field of high-frequency power electronic conversion equipment manufacturing. S1, a supporting base, a magnetic circuit closed unit, a multilayer winding stack and a magnetic field compensation layer embedded in the center between layers are arranged; S2, voltage and current phase are monitored, and equivalent inductance deviation of each branch is evaluated according to a phase deviation angle; S3, when the current of a certain branch abnormally rises, the leakage magnetic flux of the certain branch induces a rotating current in the compensation layer, a reverse eddy current compensation magnetic field is generated, the equivalent inductance of the certain branch is passively increased to force current transfer; S4, the temperature rise rate of the magnetic circuit unit is monitored, the magnetic saturation redundancy of the compensation layer is calculated according to the phase deviation angle, the switching frequency is adjusted in real time, the rotating current intensity is enhanced by high-frequency induction to make up for the loss of magnetic conductivity.

Description

Technical Field

[0001] This invention relates to the field of high-frequency power electronic conversion equipment manufacturing, specifically to an interleaved parallel winding and magnetic integration structure suitable for high-frequency transformers. Background Technology

[0002] As power electronics technology advances towards higher power density and higher frequency, high-frequency transformers, as core components of energy conversion, directly impact the reliability of the entire system through their operating efficiency and thermal stability. In actual operation, high-frequency transformers commonly face the severe challenge of uneven current distribution.

[0003] Due to the skin effect and proximity effect generated by high-frequency alternating current in conductors, the current density between layers of multilayer parallel windings often exhibits significant differences. This inconsistency in electromagnetic characteristics leads to severe circulating currents within the winding system, causing some winding layers to generate localized high-temperature hotspots due to overload, thereby accelerating the aging of insulation materials and even triggering the risk of thermal runaway.

[0004] Existing technologies typically attempt to mitigate this problem by adding parallel branches to the windings or improving the physical structure. However, in actual operating conditions, due to the unequal distances between the inner and outer windings and the magnetic core, their inherent self-inductance exhibits a natural deviation. When the system load fluctuates drastically or the operating environment temperature changes, the inductive reactance balance between the winding layers further deteriorates, leading to current distribution instability. Currently, there is a lack of effective means to monitor and dynamically adjust this inductive reactance deviation caused by differences in the electromagnetic environment in real time. This makes it impossible to maintain dynamic impedance matching between multiple windings under high loads or complex electromagnetic environments, resulting in the overall power output capability of high-frequency transformers being limited by physical limits.

[0005] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide an interleaved parallel winding and magnetic integration structure suitable for high-frequency transformers, so as to solve the problems mentioned in the background art. Specifically, the technical solution of this invention is as follows:

[0007] A method for current sharing and magnetic integration control of high-frequency transformer winding current includes:

[0008] S1. A support base, a magnetic circuit closure unit, a multi-layer winding stack, and a magnetic field compensation layer are provided. The magnetic circuit closure unit is fixed in the middle of the support base, the multi-layer winding stack is sleeved on the periphery of the magnetic circuit closure unit, and the magnetic field compensation layer is embedded in the center of the interlayer of the multi-layer winding stack and located inside the window of the magnetic circuit closure unit.

[0009] S2. Perform current distribution status monitoring, obtain the voltage phase and summative current phase at the input terminal of the multi-layer winding stack in real time, and evaluate the equivalent inductive reactance deviation between each branch of the multi-layer winding stack by calculating the phase deviation angle between the voltage phase and the summative current phase.

[0010] S3. Perform electromagnetic antagonistic passive current sharing control. When the current in a branch of the multi-layer winding stack increases abnormally, the local leakage flux generated by the branch passes through the magnetic field compensation layer and induces a counteracting reverse eddy current on its periphery. The reverse eddy current generated by the reverse eddy current compensates the magnetic field to cancel the abnormal leakage magnetic field, thereby passively increasing the local equivalent inductive reactance of the branch with abnormally increased current to force current transfer.

[0011] S4. Perform thermoelectric coupling adaptive optimization, monitor the surface temperature rise rate of the magnetic circuit closed unit, and calculate the current magnetic saturation redundancy of the magnetic field compensation layer in combination with the phase deviation angle. Adjust the switching frequency instantaneously according to the changing trend of the magnetic saturation redundancy, and use high-frequency induction to enhance the intensity of the reverse eddy current to compensate for the lack of magnetic permeability of the physical medium.

[0012] Preferably, the multilayer winding stack includes several layers of composite circuit boards and matrix transposed vias, the matrix transposed vias being distributed at the window edges of the magnetic circuit closure unit; and transposition pads are provided at the openings of the matrix transposed vias.

[0013] In step S1, a stepped transposition between layers is established through the matrix transpose via, so that the traces of each layer complete a diagonal crossing when passing through the central axis of the composite circuit board of several layers, ensuring that the physical length of each parallel path after completing a cycle is consistent with the electromagnetic environment.

[0014] Preferably, the magnetic circuit closure unit includes a first magnetic core block and a second magnetic core block that are mated together, wherein a physical air gap is provided between the mating surfaces of the first magnetic core block and the second magnetic core block, and the physical air gap is filled with a ceramic heat sink.

[0015] Preferably, step S2 includes:

[0016] Real-time monitoring of the total input voltage signal and the summed current signal of each parallel branch;

[0017] The lag time of the total current signal relative to the voltage phase is determined, and when the lag time increases, the severity of circulating current inside the multilayer winding stack is determined to increase.

[0018] Preferably, the magnetic field compensation layer includes a magnetic particle coating and an unloaded copper foil ring, wherein the magnetic particle coating is located in the physical center layer of the multilayer winding stack.

[0019] The steps in S3 include:

[0020] The magnetic focusing effect of the magnetic particle coating is used to guide the enhanced leakage magnetic flux toward the unloaded copper foil ring.

[0021] A reverse eddy current field is generated within the unloaded copper foil ring. The reverse eddy current field cancels out the magnetomotive force generated by the abnormal leakage magnetic field, thereby achieving automatic current balance at the physical level.

[0022] Preferably, step S4 includes:

[0023] Set the physical saturation magnetic flux limit value of the magnetic particle coating;

[0024] The magnetic saturation redundancy is obtained by subtracting the real-time induced magnetic flux strength from the physical saturation magnetic flux limit value.

[0025] When the magnetic saturation redundancy continues to decrease and the branch current shows a non-linear upward trend, a frequency jump command is executed to increase the switching frequency.

[0026] Preferably, the magnetic particle coating is formed by mixing and curing manganese zinc ferrite microparticles and polyimide resin in a preset ratio, and completely covers the winding projection area within the window of the magnetic circuit closure unit.

[0027] Preferably, the unloaded copper foil ring is physically nested around the outer periphery of the magnetic particle coating, and the unloaded copper foil ring is electrically suspended, maintaining a preset insulation distance from the multilayer winding stack.

[0028] A high-frequency transformer winding current sharing and magnetic integration device, comprising:

[0029] The main frame includes a support base and a magnetic circuit closure unit connected to the support base by fastening bolts.

[0030] A multi-layer winding stack is fitted around the outer periphery of the magnetic circuit closed unit;

[0031] A magnetic field compensation layer is integrated into the interlayer of the multilayer winding stack.

[0032] The system includes a controller, which is electrically connected to a phase monitoring module, a thermoelectric coupling monitoring unit, and a frequency driving unit. The phase monitoring module includes a voltage sampling network and a current sensor, the thermoelectric coupling monitoring unit includes a thermistor, and the frequency driving unit includes a PWM drive control circuit.

[0033] Preferably, an insulating pad is fixed to the top of the support base by bolts. The insulating pad has a through hole in the center for the magnetic circuit closure unit to pass through. A positioning post is provided at the corner of the insulating pad. A limiting groove is machined on the inner side of the positioning post to cooperate with the outer edge of the multi-layer winding stack.

[0034] Compared with the prior art, the present invention has the following improvements and advantages:

[0035] 1. By introducing a magnetic field compensation layer, the reverse eddy current field generated by Faraday's law of electromagnetic induction counteracts the abnormal leakage magnetic field. This physical-level automatic adjustment mechanism can instantaneously increase the inductive reactance of high-current branches without the need for complex active circuits, making the current distribution more uniform and effectively alleviating the local overheating phenomenon caused by the skin effect and proximity effect;

[0036] 2. By employing matrix transpose vias to execute periodic rotation logic of spatial position, the physical length of each winding layer after completing a cycle tends to be equal to its average distance relative to the magnetic core. This spatial symmetry eliminates the phenomenon of interlayer mutual inductance mismatch from the source, controls the cumulative error of the physical path to a very small range, and promotes the uniform penetration of current between multiple copper foil layers;

[0037] 3. By monitoring magnetic saturation redundancy and introducing frequency jump commands, the electromagnetic damping of the magnetic field compensation layer is enhanced by step-wise increases in the switching frequency within the adjustment dead zone where the magnetic material is close to saturation. This thermoelectric coupling optimization strategy ensures the operational reliability of the transformer under high power and high load fluctuation environments, compensating for the limitations of the lack of magnetic permeability in the physical medium.

[0038] 4. The high thermal conductivity ceramic heat sink filled within the physical air gap, together with the supporting base, forms an efficient heat conduction path, rapidly dissipating the heat generated by the air gap edge effect. Simultaneously, the interference fit design of the positioning column and the limiting slide groove provides mechanical stability while absorbing thermal stress, ensuring structural stability under high-frequency vibration conditions. Attached Figure Description

[0039] The present invention will be further explained below with reference to the accompanying drawings and embodiments:

[0040] Figure 1 This is a schematic diagram of the external structure of the device;

[0041] Figure 2 This is a schematic diagram of the support base structure of this device;

[0042] Figure 3 This is a schematic diagram showing the positional relationship between the multi-layer winding stack and the magnetic field compensation layer of this device;

[0043] Figure 4 This is a schematic diagram of the magnetic circuit closure unit of this device;

[0044] Figure 5 This is a schematic diagram of the process flow of the method of the present invention.

[0045] In the diagram: 100, Support base; 110, Insulating pad; 120, Positioning column; 200, Magnetic circuit closure unit; 210, First magnetic core block; 220, Second magnetic core block; 300, Multi-layer winding stack; 310, Several-layer composite circuit board; 320, Matrix transpose via; 330, Transposition pad; 400, Magnetic field compensation layer; 410, Magnetic particle coating; 420, Unloaded copper foil ring; 500, Controller. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0047] Example 1:

[0048] Please see Figure 1-5 This invention provides a method for current sharing and magnetic integration control of high-frequency transformer winding current, comprising:

[0049] S1. A support base 100, a magnetic circuit closure unit 200, a multi-layer winding stack 300, and a magnetic field compensation layer 400 are provided. The magnetic circuit closure unit 200 is fixed in the middle of the support base 100, the multi-layer winding stack 300 is sleeved on the periphery of the magnetic circuit closure unit 200, and the magnetic field compensation layer 400 is embedded in the center of the interlayer of the multi-layer winding stack 300 and located inside the window of the magnetic circuit closure unit 200.

[0050] S2. Perform current distribution status monitoring, obtain the voltage phase and summative current phase at the input terminal of the multi-layer winding stack 300 in real time, and evaluate the equivalent inductive reactance deviation between each branch of the multi-layer winding stack 300 by calculating the phase deviation angle between the voltage phase and the summative current phase.

[0051] The input to this processing flow is the raw voltage sampling signal from the phase monitoring module and the current signal aggregated from each branch. The specific steps are as follows: Step 1, the controller 500 captures the zero-crossing moments of the voltage and current signals through a high-speed analog-to-digital converter; Step 2, it calculates the time difference between the two signals and converts it into a phase angle by combining it with the real-time operating frequency; Step 3, it compares this angle with a preset equilibrium state reference value. The final output phase deviation angle is used to quantitatively evaluate the equivalent inductive reactance deviation between the branches of the multi-layer winding stack 300 and serves as the basis for deciding whether to initiate S3 passive current sharing or S4 frequency optimization.

[0052] S3. Perform electromagnetic antagonistic passive current sharing control. When the current in a branch of the multi-layer winding stack 300 rises abnormally, the local leakage flux generated by the branch passes through the magnetic field compensation layer 400 and induces a counteracting reverse eddy current on its periphery. The reverse eddy current generated by the reverse eddy current compensates the magnetic field to cancel the abnormal leakage magnetic field, thereby passively increasing the local equivalent inductive reactance of the branch with abnormally high current to force current transfer.

[0053] S4. Perform thermoelectric coupling adaptive optimization, monitor the surface temperature rise rate of the magnetic circuit closed unit 200, and calculate the magnetic saturation redundancy of the current magnetic field compensation layer 400 in combination with the phase deviation angle. Adjust the switching frequency instantaneously according to the changing trend of the magnetic saturation redundancy, and use high-frequency induction to enhance the intensity of the reverse eddy current to compensate for the lack of magnetic permeability of the physical medium.

[0054] The thermoelectric coupling adaptive optimization model aims to address the degradation of magnetic permeability in magnetic materials at high temperatures or high magnetic flux density. Logically, this model correlates the temperature rise rate of the magnetic circuit closed unit 200 with the magnetic state of the magnetic field compensation layer 400. Its physical significance lies in using dynamic adjustment in the frequency dimension to compensate for the physical limitations of the material dimension; that is, when thermal effects cause a decrease in magnetic properties, the switching frequency is increased to increase the rate of change of magnetic flux. ,in This is to increase the magnetic flux, thereby enhancing the reverse eddy current intensity within the unloaded copper foil ring 420 and maintaining the constant electromagnetic compensation effect;

[0055] In existing high-frequency transformers, uneven interlayer current due to skin effect and proximity effect often leads to localized overheating during operation. The support base 100 provides a stable physical support reference and heat conduction path for the entire transformer. The magnetic circuit closure unit 200 is rigidly fixed to the center of the support base 100 by fastening bolts, ensuring the stability of the magnetic circuit trajectory. The multi-layer winding stack 300, as the main body for current transmission, is fitted around the outer window area of ​​the magnetic circuit closure unit 200, utilizing the multi-layer structure to reduce high-frequency AC resistance. The magnetic field compensation layer 400 is embedded on the interlayer geometric axis of the multi-layer winding stack 300. For example, in the ten-layer circuit board structure of this embodiment, it is placed between the fifth and sixth layers. This position is beneficial for maximizing the capture of symmetrically distributed leakage magnetic fields.

[0056] During current distribution status monitoring, the phase monitoring module acquires the total voltage waveform at the input of the multi-layer winding stack 300 and the summarized current waveform collected by the current transformer. The controller 500 uses a TMS320F28335 chip and its on-chip integrated 12-bit high-speed analog-to-digital converter to synchronously sample the analog voltage and current signals. The calculation logic is as follows: the controller 500 captures the zero-crossing point of the voltage signal. Zero-crossing point of the current signal Calculate the time difference According to the current operating frequency of the transformer The phase deviation angle is derived. Phase deviation angle The numerical change directly corresponds to the change in the total inductance inside the winding system. When the impedance between parallel branches is inconsistent, the hysteresis angle will shift, thereby evaluating the equivalent inductive reactance deviation between branches.

[0057] Electromagnetic antagonism passive current sharing control is achieved through the physical characteristics of the magnetic field compensation layer 400. When the current density of a certain conductive layer in the multilayer winding stack 300 increases abnormally due to enhanced electromagnetic coupling, the conductive layer will generate stronger local leakage flux within the magnetic core window. This leakage flux passes through the magnetic field compensation layer 400. The magnetic particles inside the magnetic field compensation layer 400, due to magnetization, lead the magnetic field lines to the unloaded copper foil ring 420. The unloaded copper foil ring 420 generates a reverse induced current according to Faraday's law of electromagnetic induction. This current generates a compensation magnetic field, which is opposite in direction to the original abnormal leakage magnetic field. Through the magnetic flux cancellation mechanism, the increase in flux linkage in the branch with abnormally high current is hindered, which is equivalent to increasing the inductive reactance of the branch. The current flow resistance in the branch with increased inductive reactance becomes larger, naturally diffusing to other branches with relatively lower inductive reactance.

[0058] The calculation logic is based on the phase deviation angle. Equivalent inductance of the system The mathematical relationship between them. The phase deviation angle θ is calculated using the zero-crossing time difference between the voltage and current signals. Its relationship with the equivalent inductance L follows the logic of the tangent function, and its mathematical mapping relationship follows the formula:

[0059] ;

[0060] in, It is the angular frequency of the current. The total equivalent inductive reactance of the multi-layer winding system, This is the equivalent resistance of the winding circuit.

[0061] When the magnetic particle coating 410 approaches saturation, its magnetic permeability The nonlinear decrease causes a reduction in the equivalent inductance L, which in turn causes a phase deviation angle. When the offset direction changes, the controller 500 monitors... The slope of the change is used to deduce the distance of the magnetic flux density relative to the saturation point, thus obtaining the magnetic saturation redundancy. Here, The detected phase angle, The equivalent inductive reactance parameter of the multilayer winding system, The real-time permeability of the magnetic particle coating 410 enables automatic current distribution through this physical-level antagonism, reducing the current load on single-layer windings.

[0062] During thermoelectric coupling adaptive optimization, the thermoelectric coupling monitoring unit monitors the temperature of the magnetic circuit closed unit 200. The sensor uses an MF52 type negative temperature coefficient thermistor; the voltage signal it acquires is processed by a bridge balancing circuit and then input to the controller 500, which calculates the temperature rise rate in real time. The current magnetic saturation redundancy is calculated by combining the aforementioned phase deviation angle. The magnetic saturation redundancy is a dynamic quantitative safety indicator used to characterize the degree to which the current operating point of the magnetic particle coating 410 is far from its physical saturation limit. It is the key logical judgment basis for preventing the failure of the magnetic field compensation layer 400 adjustment function and the runaway of the branch current.

[0063] This redundancy is obtained by subtracting the real-time induced magnetic flux density from a preset physical saturation magnetic flux limit value, and is derived from the integral of the input voltage and current drop. When the redundancy falls below a preset safety threshold, a switching frequency jump will be triggered to enhance the compensation effect using high-frequency induction and to sense the magnetic flux density in real time. The calculation follows the integral form of Faraday's law, that is:

[0064] ;

[0065] in The number of turns in the winding. This is the effective cross-sectional area of ​​the magnetic core. Input voltage, For real-time current, This is the equivalent resistance of the winding circuit.

[0066] The calculation logic for magnetic saturation redundancy is as follows: the saturation magnetic induction intensity limit of the preset magnetic particle coating 410 is... Subtract the dynamic magnetic flux density derived from the real-time voltage phase. ;when When the difference between the magnetic flux and the branch current continues to decrease and exhibits a non-linear growth slope, it is determined that the magnetic medium is about to lose its regulating ability. The controller 500 then controls the frequency drive unit to instantaneously increase the switching frequency from the reference value. This frequency increase enhances the sensitivity of the magnetic field compensation layer 400 to changes in magnetic flux, utilizing the enhanced eddy current intensity to construct additional electromagnetic damping near the saturation point of the magnetic material, thereby compensating for the regulating dead zone caused by the material's physical permeability limit.

[0067] The multilayer winding stack 300 includes several layers of composite circuit boards 310, preferably ten layers of composite circuit boards in this embodiment, and matrix transpose vias 320, which are distributed at the window edges of the magnetic circuit closure unit 200.

[0068] In step S1, a stepped transposition between layers is established through matrix transpose vias 320, so that the traces of each layer complete a diagonal crossing when crossing the central axis of several layers of composite circuit board 310, ensuring that the physical length of each parallel path after completing a cycle is consistent with the electromagnetic environment.

[0069] The ten-layer composite circuit board 310, serving as the physical carrier of high-frequency current, has a total thickness of 2.4 mm, with each conductive copper foil layer being 70 micrometers thick, effectively carrying high-frequency, high-current loads. Matrix transposed vias 320 are evenly distributed in the trace transition area near the magnetic core window, with a diameter of 0.4 mm. Due to the unequal distances between the inner and outer windings and the magnetic core, the resulting self-inductance exhibits inherent differences. The matrix transposed vias 320 are implemented using a combination of blind and buried via technology and through-hole technology in PCB manufacturing. The copper plating thickness on the inner wall of these vias is no less than 35 micrometers to reduce contact resistance during high-current flow between layers. The area of ​​the transposed pads 330 is designed to be 2.5 times the cross-sectional area of ​​the transposed vias. This area redundancy design ensures reliable electrical connections under high-frequency vibration conditions through solder filling.

[0070] The matrix transpose via 320 implements a periodic rotation logic of spatial position. For example, the outer loop trace in the first layer descends to the middle loop position of the second layer through the via after passing the first transpose point. When passing the central axis, i.e., the intersection of the fifth and sixth layers, it performs a diagonal cross-layer operation through a specific transposition pad 330, allowing it to enter the inner loop region of the seventh or eighth layer. Through this step-like path transformation, after completing the cycle of the entire ten-layer stack, the average distance of each parallel branch relative to the magnetic circuit closure unit 200 in geometric space tends to be equal. The dwell length of the trace in each quadrant is precisely aligned, so that the cumulative error of the physical path length is controlled within 0.1 mm. This spatial symmetry eliminates the phenomenon of interlayer mutual inductance mismatch from the source, reduces the current discrimination caused by the winding arrangement order, and promotes the uniform penetration of current between multiple copper foils.

[0071] The magnetic circuit closure unit 200 includes a first magnetic core block 210 and a second magnetic core block 220 that are mated together. A physical air gap is provided between the mating surfaces of the first magnetic core block 210 and the second magnetic core block 220, and the physical air gap is filled with ceramic heat sinks.

[0072] The first magnetic core block 210 and the second magnetic core block 220 are made of DMR51 PQ-type power ferrite, which has low unit volume loss. The two magnetic core blocks are connected in a mirror-symmetrical manner. A 0.5 mm physical air gap is left at the joint surface of the central column of the magnetic circuit. The purpose of the physical air gap is to increase the equivalent magnetic reluctance of the magnetic circuit, thereby expanding the linear operating range of the magnetic core and preventing primary short circuits caused by instantaneous saturation of the magnetic core under large load current. Because the magnetic lines of force at the air gap will diverge, generating an edge magnetic field, it is easy to cause local eddy current hot spots in the nearby winding layers. The ceramic heat sink filled in the physical air gap is made of aluminum nitride, which has extremely high thermal conductivity and is an electrical insulator. The ceramic heat sink directly contacts the joint surface of the magnetic core, quickly conducting the heat accumulated in the air gap area to the support base 100 for dissipation. The first magnetic core block 210 and the second magnetic core block 220 are constrained by epoxy resin and mechanical clamping mechanism, such as bolt brackets with spring washers. This combination structure of air gap and heat sink improves the thermal stability and power density of the magnetic circuit system and reduces the influence of thermal stress on magnetic permeability.

[0073] The steps in S2 include:

[0074] Real-time monitoring of the total input voltage signal and the summed current signal of each parallel branch;

[0075] The lag time of the total current signal relative to the voltage phase is determined. When the lag time increases, the severity of the circulating current inside the multilayer winding stack 300 is determined to increase.

[0076] The total input voltage signal is obtained by a high-voltage divider sampling network connected in parallel to the input bus, and the summed current signal is obtained by a Rogowski coil or Hall sensor connected in series to the output bus. The controller 500 retrieves the internal timer to record the voltage rising edge trigger time. When the aggregated current signal generates a rising edge pulse after passing through the zero comparator, the current trigger time is recorded. Determine the lag time The calculation logic is set as follows: for a specific load impedance, It should be within a relatively stable fluctuation range. When uncontrolled circulating currents are generated inside the multi-layer winding stack 300 due to inductive reactance mismatch between layers, these circulating currents will establish additional inductive energy storage outside the main magnetic circuit, manifesting as an enhanced inductive reactance characteristic of the system as a whole. Lag time The increase in lag time represents an increase in circulating current energy consumption, and each increase in sampling period indicates a deterioration in the interlayer power balance. By monitoring the dynamic trajectory of the lag time, the system can achieve real-time online diagnosis of the health of internal parallel branches without disassembling the windings, providing a quantitative time benchmark for the intervention of current sharing strategies.

[0077] The magnetic field compensation layer 400 includes a magnetic particle coating 410 and an unloaded copper foil ring 420. The magnetic particle coating 410 is located in the physical center layer of the multilayer winding stack 300.

[0078] The steps in S3 include:

[0079] The magnetic particle coating 410 is used to concentrate the magnetic flux, which is then directed toward the unloaded copper foil ring 420.

[0080] A reverse eddy current field is generated within the unloaded copper foil ring 420. The reverse eddy current field cancels out the magnetomotive force generated by the abnormal leakage magnetic field, thereby achieving automatic current balance at the physical level.

[0081] The magnetic particle coating 410 is deployed at the central axis of the multi-layer winding stack 300, i.e., on the symmetrical plane of the leakage magnetic field intensity distribution. When an abnormal leakage magnetic field is generated in a winding due to a sudden increase in load, the originally divergent leakage magnetic lines are attracted by the highly permeable particles inside the magnetic particle coating 410 as they pass through the central axis layer. The magnetic particle coating 410 acts as a controlled magnetic permeability channel, converging and guiding these excess magnetic fluxes to the edge. The unloaded copper foil ring 420 is physically nested around the peripheral edge of the magnetic particle coating 410. When the converged strong magnetic flux passes through the hollow area of ​​the unloaded copper foil ring 420, it causes a drastic change in the magnetic flux linkage within the ring, exciting a rotating reverse eddy current inside the unloaded copper foil ring 420. The magnetomotive force generated by the eddy current... Opposite to the direction of the magnetomotive force of the dominant leakage magnetic field, the effective flux linkage of this branch is weakened according to the principle of magnetic circuit superposition, resulting in an increase in its dynamic inductance. This is because the unloaded copper foil ring 420 generates a reverse magnetic field that cancels out some of the leakage magnetic field, suppressing the flux linkage change in the corresponding high-current branch. According to the definition of self-inductance, the instantaneous equivalent inductive reactance of this branch is forced to increase. This, in parallel circuits, forces current to flow to other winding layers with lower inductive reactance through impedance matching effects, while the originally overloaded electrical energy is forcibly guided to other parallel paths. This magnetic field compensation layer 400 design utilizes the spontaneous conversion law of electromagnetic energy, transforming harmful leakage magnetic energy into the power to adjust inductive reactance, achieving dynamic impedance matching between multiple windings, and promoting a more uniform current distribution.

[0082] In addition, the reverse compensation magnetic field generated by the unloaded copper foil ring 420 substantially changes the equivalent permeability of the branch in the corresponding region. By reducing the effective magnetic reluctance change rate of the local magnetic circuit, an electromagnetic buffer is provided before the magnetic material enters the nonlinear region, thereby enhancing the damping effect of the system on local current fluctuations and maintaining the dynamic impedance matching between multiple windings in a physical sense.

[0083] The steps in S4 include:

[0084] Set the physical saturation magnetic flux limit value for the magnetic particle coating 410;

[0085] By the physical saturation magnetic induction intensity limit value Subtract real-time induced magnetic flux density Magnetic saturation redundancy is obtained ;

[0086] When the magnetic saturation redundancy continues to decrease and the branch current shows a nonlinear upward trend, a frequency switching command is executed to increase the switching frequency.

[0087] The physical saturation magnetic flux limit value of the magnetic particle coating 410 is a critical magnetic induction intensity value determined based on the manganese-zinc ferrite content in its material composition. The controller 500's calculation program detects the magnetic flux density in real time. Based on the integral form of Faraday's law, the real-time induced magnetic flux density is calculated as follows: Magnetic saturation redundancy ;

[0088] When the device operates under high load, due to the nonlinear magnetization curve of the ferrite material, the permeability drops rapidly as the magnetic flux density approaches the saturation point. The continuous decrease in redundancy Res indicates that the passive current sharing mechanism is about to fail due to magnetic circuit saturation. When the branch current waveform begins to deviate from a sinusoidal or triangular wave trajectory, exhibiting typical saturation distortion peaks, the controller 500 immediately executes a frequency jump. The switching frequency is exemplarily increased from 100kHz to 150kHz or higher via the frequency drive unit. The increase in switching frequency leads to a change in the rate of change of magnetic flux per unit time. Increase. According to the eddy current loss formula, the eddy current induction intensity in the unloaded copper foil ring 420 is proportional to the square of the frequency.

[0089] During the specific execution judgment, the controller 500 continuously compares the real-time magnetic saturation redundancy with the initial set redundancy. When the real-time redundancy decreases to less than 10% of the initial value and the growth slope of the branch current exceeds the preset current threshold, the frequency drive unit will change the switching frequency from the reference operating frequency. Instantly boost to the target frequency Target frequency The calculation logic is 1.5 times the base operating frequency, that is... The induction intensity of the unloaded copper foil ring 420 is enhanced by a step increase in frequency. This represents the initial operating frequency of the device under rated load. This represents the increased working frequency after executing the compensation logic.

[0090] This frequency compensation logic utilizes the stronger electromagnetic induction effect at high frequencies. When the material enters the magnetic saturation adjustment dead zone, it enhances the passive adjustment force through frequency dimension means, ensuring the balance of winding current under extreme operating conditions.

[0091] The magnetic particle coating 410 is formed by mixing and curing manganese zinc ferrite particles and polyimide resin in a preset ratio, and completely covers the winding projection area within the window of the magnetic circuit closure unit 200.

[0092] The selection of materials for the magnetic particle coating 410 takes into account both magnetic properties and mechanical reliability. In this hybrid curing system, the mass percentage of manganese-zinc ferrite particles is set as follows: The mass percentage of polyimide resin is set as follows: ,in ,and This ratio range ensures that the coating possesses sufficient magnetic permeability while maintaining the physical strength to resist the mechanical stress generated by the high-frequency alternating magnetic field, preventing particle shedding or coating cracking. Manganese-zinc ferrite microparticles, as functional fillers, provide the necessary magnetization properties, enabling the coating to guide leakage magnetic fields; polyimide resin, as the matrix material, possesses excellent high-temperature resistance, capable of withstanding continuous operating temperatures above 180 degrees Celsius without physical degradation. Both are uniformly dispersed through a specific mixing process, ensuring the isotropic nature of the coating's magnetic permeability.

[0093] This full-coverage design means that any abnormal magnetic leakage generated in any part of the winding trace will be detected and contained by the coating. The chemical stability of polyimide ensures that the interface between the magnetic particles and the resin remains strong during the frequent thermal cycling of the transformer, preventing delamination or cracking and maintaining a long-term stable electromagnetic compensation effect.

[0094] The unloaded copper foil ring 420 is physically nested around the outer periphery of the magnetic particle coating 410, and the unloaded copper foil ring 420 is electrically suspended, maintaining a preset insulation distance from the multilayer winding stack 300.

[0095] The physical nesting of the unloaded copper foil ring 420 is achieved by fastening it to the side edge of the magnetic particle coating 410, forming a compact magnetic field interaction assembly. The connection of the unloaded copper foil ring 420 is designed to be electrically levitated, meaning that it is neither connected to the transformer's common ground nor to any potential node, but only exchanges energy with the main winding through the spatial magnetic field. A 0.5 mm insulation gap is maintained between the unloaded copper foil ring 420 and the multilayer winding stack 300. This functionally limited connection method ensures that only the core functions of capturing leakage magnetic fields and inducing eddy currents are achieved. The specific fixing method can be high-temperature tape bonding or positioning and fixing using the reserved groove on the positioning post 120. The electrically levitated characteristic avoids the introduction of additional common-mode interference and parasitic capacitive current, while the 0.5 mm gap prevents air breakdown or creepage between the winding and the compensation layer under high voltage conditions, ensuring the overall safety of the circuit.

[0096] By keeping the unloaded copper foil ring 420 in an electrically levitated state, the direct potential correlation between the compensation layer and the main circuit is cut off, effectively preventing common-mode noise generated by high-frequency switching from being coupled to the signal control circuit through parasitic capacitance, thus ensuring the accuracy of phase monitoring.

[0097] Example 2:

[0098] Please see Figure 1-4 A high-frequency transformer winding current sharing and magnetic integration device, comprising:

[0099] The main frame includes a support base 100 and a magnetic circuit closure unit 200 connected to the support base 100 by fastening bolts;

[0100] A multi-layer winding stack 300 is sleeved on the outer periphery of the magnetic circuit closed unit 200;

[0101] The magnetic field compensation layer 400 is integrated into the interlayer of the multilayer winding stack 300;

[0102] The controller 500 is electrically connected to the phase monitoring module, the thermoelectric coupling monitoring unit, and the frequency drive unit, respectively. The phase monitoring module includes a voltage sampling network and a current sensor, the thermoelectric coupling monitoring unit includes a thermistor, and the frequency drive unit includes a PWM drive control circuit.

[0103] The main frame serves as the physical carrier of the transformer. The support base 100 is made of aluminum alloy to balance strength and heat dissipation, and the magnetic circuit closure unit 200 is embedded in its mounting slot. The fastening bolts are made of non-magnetic materials such as stainless steel to prevent them from heating up in the magnetic field. The multi-layer winding stack 300 is fitted around the central column of the magnetic circuit, and its plate edge is limited by a limiting groove. The magnetic field compensation layer 400 is integrated into the winding through a lamination process. The controller 500 uses a high-performance embedded processor, such as the TMS320F28335. The controller 500 establishes signal connections with each submodule: the Hall current sensor ACS712 in the phase monitoring module provides current phase information, and the negative temperature coefficient thermistor MF52 in the thermoelectric coupling monitoring unit provides temperature rise data. In actual high-frequency operating environments, the current sensor in the phase monitoring module is selected as a high-speed Hall sensor or a high-frequency current transformer with a bandwidth of over 200kHz to match the sampling requirements of the switching frequency. The signal conditioning circuit inside the controller 500 performs high-pass filtering on the raw voltage signal output by the sensor to remove DC offset and ensure that the capture accuracy of the phase zero crossing point is better than 0.5 microseconds.

[0104] The controller 500 drives the frequency drive unit according to the algorithm logic. The frequency drive unit includes a control circuit based on a PWM drive chip, which outputs commands to the gate drive module of the power MOSFET, thereby adjusting the operating frequency of the transformer in real time according to the electromagnetic balance state. This highly integrated electromagnetic and control structure enables the transformer to maintain a balanced current distribution among the winding layers across the entire power range, reducing local losses.

[0105] An insulating pad 110 is fixed to the top of the support base 100 by bolts. The center of the insulating pad 110 has a clearance hole for the magnetic circuit closing unit 200 to pass through. A positioning post 120 is provided at the corner of the insulating pad 110. A limit groove is machined on the inner side of the positioning post 120 to form a fit with the outer edge of the multi-layer winding stack 300.

[0106] The insulating pad 110 is made of FR4 epoxy resin board with a thickness of 2 mm. It is set on the surface of the support base 100 and serves as a reference for electrical isolation and magnetic core fixation. A rectangular clearance hole is opened in the center of the insulating pad 110. The first magnetic core block 210 of the magnetic circuit closure unit 200 passes through the hole and is directly bonded to the support base 100 with epoxy resin adhesive. The positioning posts 120 are vertically installed at the four corners of the insulating pad 110. The inner sidewall of the positioning posts 120 is machined with a precision-extended limiting groove. The outer edge of the circuit board of the multilayer winding stack 300 slides into the limiting groove of the positioning post 120 to form an interference fit connection.

[0107] Considering the thermal effects during transformer operation, a thermal expansion buffer gap of 0.05 mm to 0.08 mm is reserved on the inner wall of the limiting slide. The interference fit is only reflected in the local protrusion structure at the bottom of the limiting slide. This structure is made of an insulating pad material with slight elasticity, which can absorb the axial stress of the material caused by temperature rise while ensuring the mechanical stability of the ten-layer composite circuit board 310. This structural design ensures that the freedom of the multi-layer winding stack 300 in the horizontal and vertical directions is strictly limited, preventing the windings from colliding with the magnetic core under vibration. At the same time, the positioning column 120 also acts as a structural component supporting the multi-layer conductors, ensuring the accuracy of the interlayer spacing. The clearance design of the insulating pad 110 ensures that heat can be smoothly conducted from the bottom of the magnetic core to the heat dissipation surface of the support base 100, optimizing the overall thermal distribution of the transformer and ensuring the structural reliability under long-term operation.

[0108] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for integrated current sharing and magnetic control of high-frequency transformer winding current, characterized in that, include: S1. A support base (100), a magnetic circuit closure unit (200), a multi-layer winding stack (300), and a magnetic field compensation layer (400) are provided. The magnetic circuit closure unit (200) is fixed in the middle of the support base (100), the multi-layer winding stack (300) is sleeved on the periphery of the magnetic circuit closure unit (200), and the magnetic field compensation layer (400) is embedded in the interlayer center of the multi-layer winding stack (300) and located inside the window of the magnetic circuit closure unit (200). S2. Perform current distribution status monitoring, obtain the voltage phase and summative current phase at the input terminal of the multi-layer winding stack (300) in real time, and evaluate the equivalent inductive reactance deviation between each branch of the multi-layer winding stack (300) by calculating the phase deviation angle between the voltage phase and the summative current phase. S3. Perform electromagnetic antagonistic passive current sharing control. When the current in a branch of the multi-layer winding stack (300) rises abnormally, the local leakage flux generated by the branch passes through the magnetic field compensation layer (400) and induces a counteracting reverse eddy current on its periphery. The reverse eddy current generated by the reverse eddy current compensates the magnetic field to cancel the abnormal leakage magnetic field, thereby passively increasing the local equivalent inductive reactance of the branch with abnormally high current to force current transfer. S4. Perform thermoelectric coupling adaptive optimization, monitor the surface temperature rise rate of the magnetic circuit closed unit (200), and calculate the current magnetic saturation redundancy of the magnetic field compensation layer (400) in combination with the phase deviation angle. Adjust the switching frequency instantaneously according to the changing trend of the magnetic saturation redundancy, and use high-frequency induction to enhance the intensity of the reverse eddy current to compensate for the lack of magnetic permeability of the physical medium. The multilayer winding stack (300) includes several layers of composite circuit boards (310) and matrix transposed vias (320). The matrix transposed vias (320) are distributed at the window edges of the magnetic circuit closure unit (200), and transposition pads (330) are provided at the openings of the matrix transposed vias (320). In step S1, a stepped transposition between layers is established through the matrix transpose via (320), so that the traces of each layer complete a diagonal crossing when crossing the central axis of the composite circuit board (310) of the several layers, ensuring that the physical length of each parallel path after completing a cycle is consistent with the electromagnetic environment. The magnetic field compensation layer (400) includes a magnetic particle coating (410) and an unloaded copper foil ring (420), wherein the magnetic particle coating (410) is located in the physical center layer of the multilayer winding stack (300). The steps in S3 include: The magnetic flux is directed toward the unloaded copper foil ring (420) by utilizing the magnetic focusing effect of the magnetic particle coating (410). A reverse eddy current field is generated within the unloaded copper foil ring (420). The reverse eddy current field cancels out the magnetomotive force generated by the abnormal leakage magnetic field, thereby achieving automatic current balance at the physical level.

2. The high-frequency transformer winding current sharing and magnetic integration control method according to claim 1, characterized in that, The magnetic circuit closure unit (200) includes a first magnetic core block (210) and a second magnetic core block (220) that are mated together. A physical air gap is provided between the mating surfaces of the first magnetic core block (210) and the second magnetic core block (220), and the physical air gap is filled with ceramic heat sinks.

3. The method for current sharing and magnetic integration control of high-frequency transformer windings according to claim 1, characterized in that, The steps in S2 include: Real-time monitoring of the total input voltage signal and the summed current signal of each parallel branch; The lag time of the current signal after the sum of the parallel branches is determined relative to the voltage phase. When the lag time increases, the severity of the circulating current inside the multilayer winding stack (300) is determined to increase.

4. The high-frequency transformer winding current sharing and magnetic integration control method according to claim 1, characterized in that, The steps in S4 include: Set the physical saturation magnetic flux limit value of the magnetic particle coating (410); The magnetic saturation redundancy is obtained by subtracting the real-time induced magnetic flux strength from the physical saturation magnetic flux limit value. When the magnetic saturation redundancy continues to decrease and the branch current shows a non-linear upward trend, a frequency jump command is executed to increase the switching frequency.

5. The high-frequency transformer winding current sharing and magnetic integration control method according to claim 4, characterized in that, The magnetic particle coating (410) is formed by mixing and curing manganese zinc ferrite particles and polyimide resin in a preset ratio, and completely covers the winding projection area within the window of the magnetic circuit closure unit (200).

6. The high-frequency transformer winding current sharing and magnetic integration control method according to claim 1, characterized in that, The unloaded copper foil ring (420) is physically nested around the outer periphery of the magnetic particle coating (410), and the unloaded copper foil ring (420) is electrically suspended, maintaining a preset insulation distance with the multilayer winding stack (300).

7. A high-frequency transformer winding current sharing and magnetic integration device, used to implement the high-frequency transformer winding current sharing and magnetic integration control method according to any one of claims 1-6, characterized in that, include: The main frame includes a support base (100) and a magnetic circuit closure unit (200) connected to the support base (100) by fastening bolts. A multi-layer winding stack (300) is sleeved on the outer periphery of the magnetic circuit closure unit (200); A magnetic field compensation layer (400) is integrated between the layers of the multilayer winding stack (300); The controller (500) is electrically connected to the phase monitoring module, the thermoelectric coupling monitoring unit and the frequency driving unit respectively; the phase monitoring module includes a voltage sampling network and a current sensor, the thermoelectric coupling monitoring unit includes a thermistor and the frequency driving unit includes a PWM drive control circuit.

8. The high-frequency transformer winding current sharing and magnetic integration device according to claim 7, characterized in that, An insulating pad (110) is fixed to the top of the support base (100) by bolts. The center of the insulating pad (110) is provided with a clearance through hole for the magnetic circuit closing unit (200) to pass through. A positioning post (120) is provided at the corner of the insulating pad (110). A limit groove is machined on the inner side of the positioning post (120) to form a fit with the outer edge of the multi-layer winding stack (300).

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