CN113257536A

CN113257536A - Staggered full-shielded wire, transformer based on same and staggered full-shielded wire based on multiphase current

Info

Publication number: CN113257536A
Application number: CN202110400283.9A
Authority: CN
Inventors: 赵晖; 龙腾
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-04-14
Filing date: 2021-04-14
Publication date: 2021-08-13

Abstract

The invention discloses a staggered full-shielding wire with low cost, suitability for large-scale mass production, suitability for large current and high frequency, which comprises a plurality of lead layers which are overlapped up and down, wherein each lead layer is provided with a plurality of input leads and output leads, the input leads and the output leads on each layer are arranged at intervals, and the position overlapping ratio of each input lead on the upper layer and the nearest input lead on the same corresponding position on the lower layer in two adjacent lead layers is 0-100%; the overlap ratio of the output wires at the upper layer of the two adjacent wire layers and the nearest output wire at the same corresponding position on the lower layer is 0-100%. The invention also discloses a transformer based on the transformer. The invention also discloses a staggered full-shielded wire based on the multiphase current, which comprises a plurality of conductor layers which are arranged in an up-and-down overlapping manner, wherein a plurality of groups of corresponding conductor groups are arranged on each conductor layer in parallel, each group of conductor groups comprises single-phase conductors which are arranged in parallel and have the same number as the number of phases, and the single-phase conductors in the two adjacent conductor groups are arranged in a staggered manner.

Description

Staggered full-shielded wire, transformer based on same and staggered full-shielded wire based on multiphase current

Technical Field

The invention relates to an interleaved full-shielded wire, a transformer based on the interleaved full-shielded wire and an interleaved full-shielded wire based on multiphase current.

Background

Kirchhoff's current law states that for any general circuit, the circuit needs to form a closed loop. Therefore, any circuit needs to be wired in and wired out at the same time. However, with the rise of high-performance chips such as GPU, artificial intelligence chip and 5G communication chip, three new requirements appear in modern circuit development: 1, high-frequency circuit; 2. the energy to be transferred rises; 3. it is required to have small external radiation.

However, these three requirements are mutually contradictory. The high frequency of the circuit means that the skin effect and the proximity effect are significant, the current is concentrated on the surface, especially the inner surface, of the conductor, the volume of the conductor is greatly wasted, the current carrying capacity of the conductor is sharply reduced, and a large amount of energy is difficult to transfer. On the other hand, the high frequency makes the energy more easily radiated to the outside of the circuit; meanwhile, the large energy increases the total energy of the external radiation, so that how to limit the external radiation also becomes a great challenge.

In conventional low frequency or low power systems, conventional round wires are very widely used, but the problem of skin effect cannot be solved, so that the application in a large current and high frequency range is challenging. Compared with the traditional round lead, the flat conductor is simpler to manufacture and better in mechanical stability, is widely applied to the field of modern power electronics, and is also subjected to high-frequency circuit; the energy to be transferred rises; the external radiation is required to be small, and the three contradictory requirements are met. In addition, flat conductors are generally available as substitutes for circular conductors, and the high-frequency characteristics of the flat conductors themselves, particularly the skin effect, are not sufficiently analyzed.

High power density transformers, inductors, power electronic converters, generators, motors, and high power transmission lines require large currents or high frequencies to flow through, since high frequencies can reduce conductor skin depth, and large currents require larger area wires. When the skin depth is smaller than the radius of the conductor, the current density in the conductor is reduced, the copper in the conductor cannot be fully applied, the conductor material is wasted, and the conductor resistance and the system loss are increased.

In order to solve the influence of skin effect, hollow conducting wires and improved structures thereof are widely used in high-power circuit systems. A hollow conductor is a structure in which the middle of a conductor is hollowed out, leaving only the outer metal. In the hollow wire, the current is still concentrated on the surface of the wire, but since there is no metal inside the wire, the total metal consumption is small and the total weight of the wire is low.

The improved hollow conductor is formed by filling improved material in the hollow part. The most commonly used filler material is aluminum steel or coolant. The aluminum steel alloy can obviously increase the mechanical strength of the lead, and the cooling liquid can improve the thermal property of the hollow lead.

However, the most significant problem of the hollow conductor is that the manufacturing process and the winding process of the hollow conductor are complicated, and although the material used for the conductor is small, the process cost is increased, and the overall cost is not necessarily reduced. Another major problem is that the hollow portion of the hollow conductor still takes up system space. Therefore, although the material used for the hollow conductor is decreased, the overall volume and space are not decreased, and the hollow conductor is not suitable for a high power density transducer and system. Finally, the hollow conductor cannot solve the high frequency radiation problem. Therefore, despite the many advantages of hollow conductors, the use of hollow conductors is minimal in modern high frequency systems.

The signal and communication fields also face the problems of high frequency electrical signals and external radiation. The field generally uses different structures of shielding wires or twisted pairs to solve the contradiction between high frequency signals and external radiation. However, the shielded wires and the twisted pairs are only used for transmitting weak current signals, which cannot solve the problem of large current, and the shielded wires are bulky, and increase extra loss, which is not suitable for occasions with large current or high power density.

Litz wire is currently the most widely used high frequency wire considered to be the most effective. Litz wire is twisted or woven using a plurality of individually insulated conductors, each with an insulated portion. Because the cross-sectional conductor area of each individual conductor is small, the effects of the skin effect are eliminated or mitigated. The wires are twisted or woven together to increase the mechanical stability of the wire as a whole and to make the length of each wire substantially equal. Since the first commercial mass production by the new britain company in 1911, the high-frequency antenna has been widely applied in the high-frequency field. However, not only is the litz wire complex in process and high in manufacturing cost, but also the current is still extremely uneven inside the conductor due to the influence of the proximity effect, and the improvement degree of the high-frequency alternating-current impedance is limited. In addition, the litz wire is complex in structure and complex to wind, and is not suitable for large-scale mass production. In addition, each independent wire of the litz wire needs insulation, the cross section area of a transverse conductor is large, and the occupied volume is large.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the staggered full-shielding wire is low in cost, suitable for large-scale mass production, and suitable for large current, high switching frequency and low radiation.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a staggered full-shielded wire comprises a plurality of wire layers which are stacked up and down, wherein each wire layer is provided with a plurality of phase input wires and output wires, the input wires and the output wires on each layer are arranged at intervals, and the position coincidence ratio of each input wire on the upper layer in two adjacent wire layers to the nearest input wire on the same position on the lower layer is 0-100%; the overlap ratio of the output wires at the upper layer of the two adjacent wire layers and the nearest output wire at the same corresponding position on the lower layer is 0-100%.

Preferably, the conductor width of the input lead and the conductor width of the output lead are both less than 2 times the skin depth.

Preferably, the number of the input wires and the number of the output wires on all the wire layers are the same.

Preferably, the number of the input wires and the number of the output wires on the wire layer gradually increase from the uppermost layer to the lowermost layer to the middle.

As a preferred scheme, each of the input lead and the output lead comprises at least one lead monomer; the cross sections of the conductors of the input lead and the output lead are circular, rectangular or regular hexagonal.

Preferably, the conductor cross sections of the input lead and the output lead are both square.

As a preferred solution, each of said conductor layers is printed on a printed circuit board PCB; the distance between the input lead and the output lead is not more than 8 mil; the thickness of the input conducting wire and the thickness of the output conducting wire are both not more than 100 μm.

Preferably, the conductor cross-sections of the input lead and the output lead are rectangular and both have a height greater than a width.

The beneficial effect of this full shielded wire is: the fully shielded wire can greatly reduce the influence of proximity effect and skin effect, thereby solving the contradiction between high frequency and high energy transmission. On the other hand, the reversal of the crossed winding can generate an active magnetic field cancellation effect, and is an active noise reduction strategy. Unlike passive filtering or electromagnetic shielding, the magnitude of the external radiation of the circuit can be greatly reduced without adding extra volume and extra loss. Moreover, compared with the hollow conductor and the litz wire, the manufacturing of the fully shielded wire is simpler and more convenient, the manufacturing cost is lower, and the large-scale mass production is convenient.

The fully shielded wire can be widely applied to facilities such as transformers with high power density, inductors, power electronic converters, generators, motors, high-power transmission lines and the like which need to flow large current or high-frequency current.

Because the conductor width of the input lead and the conductor width of the output lead are both less than 2 times of the skin depth, the influence caused by the skin effect can be greatly reduced.

The number of the input leads and the number of the output leads on all the lead layers are consistent, so that the wiring operation is more convenient.

Because each layer of the lead layer is printed on a Printed Circuit Board (PCB), the full-shielding wire has wider application range.

The distance between the input lead and the output lead is not more than 8 mil; the thickness of the input lead and the thickness of the output lead are both not more than 100 mu m, so that the manufacturing cost can be saved under the condition of ensuring the using effect.

The other technical problem to be solved by the invention is as follows: a transformer based on the staggered full-shielded wire is provided.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a transformer comprises a primary cable and a secondary cable, wherein the turn ratio of the primary cable to the secondary cable is recorded as Np, the total number of turns of the primary cable is recorded as (Kpr multiplied by Ns) multiplied by Np, and the total number of turns of the secondary cable is recorded as (Kpr multiplied by Np) multiplied by Ns; kpr is constant and satisfies: the number of parallel wires of a primary side cable of the transformer, namely Kpr multiplied by Ns, is a positive integer, the number of parallel wires of a secondary side cable of the transformer, namely Kpr multiplied by Np, is a positive integer, the maximum current Ipmax/(Kpr multiplied by Ns) of each circle of wires of the primary side cable is smaller than a specified limit current value, and Kpr is less than or equal to SWin/(Scond multiplied (Ns + Np)) so as to ensure that the window filling coefficient of the transformer is less than or equal to 1; wherein Ipmax is the maximum current of the primary side, SWin is the window area of the transformer, and Scond is the sectional area of the single conductor; the primary cable and the secondary cable both adopt the staggered full-shielded wire.

The transformer has the beneficial effects that: the transformer adopts the staggered full-shielding wire for winding, can pass through larger high-frequency current in the area of a wire as small as possible, and reduces the external radiation of the system.

The other technical problem to be solved by the invention is as follows: the staggered full-shielded wire based on the multiphase current is low in cost, high in current and high in frequency and is suitable for large-scale mass production.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a staggered full-shielded wire based on multiphase current comprises a plurality of conductor layers which are stacked up and down, wherein each conductor layer is provided with a plurality of corresponding conductor groups in parallel, each conductor group comprises single-phase conductors which are arranged in parallel and have the same number as the number of phases, the position of a conductor monomer of each phase in a conductor group in a lower conductor layer is shifted forward/backward by one bit compared with the position of a corresponding conductor monomer of the phase in a corresponding conductor group in an upper conductor layer, and the foremost/last conductor monomer in the conductor group in the upper conductor layer corresponds to the rearmost/foremost conductor monomer in the corresponding conductor group in the lower conductor layer; the position coincidence degree of a single-phase lead of a certain phase in each lead group at the upper layer in the two adjacent lead layers and a single-phase lead of the corresponding phase in each lead group at the lower layer is 0-100%.

Preferably, the conductor width of the single-phase conductor is less than 2 times the skin depth.

Preferably, the number of the conductor sets on all the conductor layers is the same.

Preferably, the number of the wire groups on the wire layer gradually increases from the uppermost layer and the lowermost layer to the middle.

As a preferred scheme, each single-phase wire comprises at least one single wire body; the conductor section of the single-phase wire is round, rectangular or regular hexagonal.

Preferably, the conductor cross section of the single-phase wire is square.

Preferably, the conductor section of the single-phase conductor has a height greater than a width.

As a preferred solution, each of said conductor layers is printed on a printed circuit board PCB; the distance between the single-phase wires is not more than 8 mil; the thickness of the single-phase wire is not more than 100 μm.

The staggered full-shielded wire based on the multi-phase current has the beneficial effects that: due to the adoption of the staggered winding type structure, the influence of the proximity effect and the skin effect can be greatly reduced, and the contradiction between high frequency and high energy transmission can be solved. On the other hand, the reversal of the crossed winding can generate an active magnetic field cancellation effect, and is an active noise reduction strategy. Unlike passive filtering or electromagnetic shielding, the magnitude of the external radiation of the circuit can be greatly reduced without adding extra volume and extra loss.

Drawings

Fig. 1 is a conventional round conductor winding form.

Fig. 2 is a conventional rectangular conductor winding form.

FIG. 3 is a litz wire wound form.

Fig. 4 is a schematic structural diagram of an interleaved fully shielded wire according to embodiment 1.

Fig. 5 is a current distribution pattern of a round wire.

Fig. 6 is a current distribution form of a rectangular wire.

Fig. 7 is a current distribution pattern of litz wire leads.

Fig. 8 is a current distribution of the staggered bite type.

Fig. 9 is a distribution form of external radiation of a circular wire.

Fig. 10 is a distribution form of external radiation of a rectangular wire.

Fig. 11 is a distribution of the external radiation of litz wire.

Fig. 12 is a distribution of external radiation for a staggered fully shielded wire.

Fig. 13 is a schematic diagram showing the corresponding resistance of four wires, i.e., a round wire, a rectangular wire, a litz wire, and the present staggered full-shielded wire wound in a staggered manner, at different frequencies.

Fig. 14 is a schematic structural diagram of an interleaved fully shielded wire according to embodiment 2.

Fig. 15 is a schematic structural diagram of embodiment 3 of the staggered full shielded wire.

Fig. 16 is a schematic structural diagram of an interleaved fully shielded wire according to embodiment 4.

Fig. 17 is a schematic structural diagram of an interleaved fully shielded wire according to embodiment 5.

Fig. 18 is a schematic structural diagram of the staggered full shielded wire according to embodiment 6.

Fig. 19 shows a basic structure of the dc/dc converter.

Fig. 20 is a schematic diagram of a transformer.

Fig. 21 is a schematic diagram of a structure of an interleaved fully shielded wire based on multi-phase current.

Fig. 22 is a conventional multi-phase motor drive system.

Detailed Description

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

An embodiment 1 of the staggered full-shielded wire is shown in fig. 4 and comprises a plurality of wire layers which are arranged in an up-and-down overlapping mode, wherein each wire layer is provided with a plurality of input wires and output wires, the input wires and the output wires on each layer are arranged at intervals, and the overlapping ratio of the input wires on the upper layer and the nearest input wires on the lower layer at the same corresponding position in the two adjacent wire layers is 0; the position coincidence ratio of each output lead of the upper layer in the two adjacent lead layers and the nearest output lead at the same corresponding position on the lower layer is 0. Each of the input lead and the output lead comprises a single lead. The conductor widths of the input and output leads are both less than 2 times the skin depth. And the number of the input leads and the number of the output leads on all the lead layers are the same.

Fig. 5 is a current distribution pattern of a round wire. As can be seen, the center is dark (blue in the analytical software) indicating that the current density is very low in the center of the wire and the skin effect is severe. The current density is very high near the conductor, and the current density is lower at the opposite edge of the conductor, which indicates that the proximity effect also influences the current distribution.

Fig. 6 is a current distribution form of a rectangular wire. As can be seen, the smaller middle dark area (blue area in the analysis software) indicates an improved skin effect of the wire in the rectangular wire form; but the proximity effect is still severe and the current distribution is still large for adjacent conductors and small for parts away from the conductors.

Fig. 7 is a current distribution pattern of litz wire leads. As can be seen, the skin effect is already small, and especially the current of the edge conductor is already substantially evenly distributed. But the proximity effect is very severe, in conductors close to the centre the current density is very high in the part of the conductor close to the current.

Fig. 8 shows the current distribution of the staggered full-shielded wire, and as can be seen from the figure, the current distribution is extremely uniform, and the influence of the proximity effect and the skin effect is completely solved.

Fig. 9, 10 and 11 are the distribution forms of the external radiation of the round wire, the rectangular wire and the litz wire respectively. The shapes of the radiation distribution with similar external radiation sizes of the several winding forms are also similar.

Fig. 12 shows the distribution of the external radiation of the present interlaced fully shielded wire. Fig. 12 illustrates directly three problems: 1. the size of the external radiation is close to the minimum area, the radiation intensity is reduced by 2 orders of magnitude compared with the traditional radiation intensity, and the external device and personnel safety are well protected; 2. the external radiation is small, and meanwhile, the influence of the external radiation is small, and the current distribution and the voltage distribution of the lead cannot be changed due to the influence of the external radiation; 3. the small external radiation indicates that the overall leakage inductance is small.

Fig. 13 shows the corresponding resistance of four wires, i.e. a round wire, a rectangular wire, a litz wire and the present staggered full-shielded wire wound in a staggered manner, at different frequencies.

An embodiment 2 of the staggered full-shielded wire is shown in fig. 14, and the difference from the embodiment 1 is that: the position contact ratio of each input lead of the upper layer in the two adjacent lead layers to the nearest input lead at the same corresponding position on the lower layer is 30%; the overlap ratio of the output leads on the upper layer of the two adjacent lead layers to the nearest output lead on the lower layer corresponding to the same position is 30%.

An embodiment 3 of the staggered full-shielded wire is shown in fig. 15, and the difference from the embodiment 1 is that: the position contact ratio of each input lead of the upper layer in the two adjacent lead layers and the nearest input lead at the same corresponding position on the lower layer is 100%; the overlap ratio of the output leads on the upper layer of the two adjacent lead layers to the nearest output lead on the lower layer corresponding to the same position is 100%.

An embodiment 4 of the staggered full-shielded wire is shown in fig. 16, and the difference from the embodiment 1 is that: the cross sections of the conductors of the input lead and the output lead are rectangular and meet the condition that the height is larger than the width.

An embodiment 5 of the staggered full-shielded wire is shown in fig. 17, and the difference from the embodiment 1 is that: the cross sections of the conductors of the input lead and the output lead are circular.

An embodiment 6 of the staggered full-shielded wire is shown in fig. 18, and the difference from the embodiment 1 is that: the cross sections of the conductors of the input lead and the output lead are in a regular hexagon shape.

As shown in fig. 19, the basic structure of the dc/dc converter is shown. The power supply is composed of an input power supply, a switching converter, a filter and an application device/chip. The switching converter converts an input power source into a voltage required by the electric equipment or the electric chip. The power supply is carried out on the electric equipment including but not limited to a communication chip, a CPU, a GPU, a memory and a hard disk. The operating frequency of the power circuit can typically reach the MHz or even 10MHz level, and the current can approach several hundred amperes. With the switching device acting, there is a high frequency current in the system (in the forward and return paths in the figure).

When the staggered full-shielded wire is adopted, when the forward path and the reverse path are normally coupled, the system power is not influenced by the skin effect and the proximity effect any more, the power loss is greatly reduced, and the external radiation is greatly reduced.

As shown in fig. 20, a transformer includes a primary cable and a secondary cable, where a turn ratio of the primary cable to the secondary cable is represented by Np: Ns, a total number of turns of the primary cable is represented by (Kpr × Ns) × Np, and a total number of turns of the secondary cable is represented by (Kpr × Np) × Ns; kpr is constant and satisfies: the number of parallel wires of a primary cable of the transformer, namely Kpr multiplied by Ns, is a positive integer, the number of parallel wires of a secondary cable of the transformer, namely Kpr multiplied by Np, is a positive integer, and the maximum current Ipmax/(Kpr multiplied by Ns) of each turn of the wires of the primary cable is smaller than a specified limit current value (for example, smaller than the minimum current value ILIM of a Printed Circuit Board (PCB), or meets the relevant specification of the current-carrying capacity IEC 60364-5-523 of a channel line of building electricity, and the like), wherein Ipmax is the maximum current of the primary cable, and Kpr meets the requirement that the window filling coefficient of the transformer is smaller than or equal to 1; the primary cable and the secondary cable can adopt any one of the staggered full-shielded wires.

As shown in fig. 21, a structure of an interleaved fully shielded wire based on a multiphase current will be described by taking three phases as an example.

The structure of the staggered full-shielded wire based on the three-phase current comprises a plurality of layers of lead layers which are stacked up and down, wherein a plurality of groups of corresponding lead groups are arranged on each layer of lead layer in parallel, each group of lead groups comprises three single-phase leads which are arranged in parallel, namely a first lead, a second lead and a third lead, and the lead arranged at the forefront position in any lead group in the lower layer of lead layer corresponds to the lead arranged at the last in the corresponding middle lead group in the upper layer of lead layer; the wires arranged in the middle of any wire group in the lower layer of wire layer correspond to the wires arranged at the forefront in the corresponding wire group in the upper layer of wire layer; the wires arranged at the last position in any wire group in the lower layer of wire layer correspond to the wires arranged in the middle in the corresponding wire group in the upper layer of wire layer; the position coincidence degree of each first wire on the upper layer in the two adjacent wire layers and the nearest first wire on the lower layer corresponding to the same position is 100%, the position coincidence degree of each second wire on the upper layer in the two adjacent wire layers and the nearest second wire on the lower layer corresponding to the same position is 100%, and the position coincidence degree of each third wire on the upper layer in the two adjacent wire layers and the nearest third wire on the lower layer corresponding to the same position is 100%. The number of the lead groups on all the lead layers is consistent. Each of the first conductive wires, each of the second conductive wires and each of the third conductive wires includes a single conductive wire and has a rectangular cross-section.

A conventional multi-phase motor drive system is shown in fig. 22 and includes a motor drive, a multi-phase cable, and a multi-phase motor. The motor driver generates multiphase currents with the multiphase phases different by 120 degrees and supplies the multiphase currents to the motor to drive the motor to run. The length of the multi-phase cable tends to be long.

For example, in a drilling rig, each phase of cable may be as long as several hundred meters or even tens of thousands of meters, and the current may be as high as thousands of amperes. And the staggered full-shielding wire based on the multiphase current is adopted to couple the multiphase cable, so that the system power is not influenced by the skin effect and the proximity effect any more, the power loss is greatly reduced, and the external radiation is greatly reduced.

The above-mentioned embodiments are merely illustrative of the principles and effects of the present invention, and some embodiments may be used, not restrictive; it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the inventive concept of the present invention, and these changes and modifications belong to the protection scope of the present invention.

Claims

1. The utility model provides an alternating expression shield wire entirely which characterized in that: the lead comprises a plurality of lead layers which are arranged in an up-and-down overlapping mode, wherein each lead layer is provided with a plurality of input leads and output leads, the input leads and the output leads on each layer are arranged at intervals, and the position contact ratio of each input lead on the upper layer and the nearest input lead on the lower layer at the corresponding same position in the two adjacent lead layers is 0-100%; the overlap ratio of the output wires at the upper layer of the two adjacent wire layers and the nearest output wire at the same corresponding position on the lower layer is 0-100%.

2. The interleaved fully shielded wire of claim 1 further comprising: the conductor widths of the input and output leads are both less than 2 times the skin depth.

3. The interleaved fully shielded wire of claim 1 further comprising: the number of the input leads and the number of the output leads on all the lead layers are the same.

4. The interleaved fully shielded wire of claim 1 further comprising: the number of the input wires and the number of the output wires on the wire layer are gradually increased from the uppermost layer and the lowermost layer to the middle.

5. The interleaved fully shielded wire of claim 1 further comprising: each input lead and each output lead comprise at least one lead monomer; the cross sections of the conductors of the input lead and the output lead are circular, rectangular or regular hexagonal.

6. The interleaved fully shielded wire of claim 5 further comprising: the cross sections of the conductors of the input lead and the output lead are square.

7. The interleaved fully shielded wire of claim 5 further comprising: the cross sections of the conductors of the input lead and the output lead are rectangular and meet the condition that the height is larger than the width.

8. The interleaved fully shielded wire of any of claims 1-7 further comprising: each layer of the lead layers is printed on a Printed Circuit Board (PCB); the distance between the input lead and the output lead is not more than 8 mil; the thickness of the input conducting wire and the thickness of the output conducting wire are both not more than 100 μm.

9. A transformer comprises a primary cable and a secondary cable, wherein the turn ratio of the primary cable to the secondary cable is recorded as Np, the total number of turns of the primary cable is recorded as (Kpr multiplied by Ns) multiplied by Np, and the total number of turns of the secondary cable is recorded as (Kpr multiplied by Np) multiplied by Ns; the method is characterized in that: kpr is constant and satisfies: the number of parallel wires of a primary side cable of the transformer, namely Kpr multiplied by Ns, is a positive integer, the number of parallel wires of a secondary side cable of the transformer, namely Kpr multiplied by Np, is a positive integer, the maximum current Ipmax/(Kpr multiplied by Ns) of each circle of wires of the primary side cable is smaller than a specified limit current value, and Kpr is less than or equal to SWin/(Scond multiplied (Ns + Np)) so as to ensure that the window filling coefficient of the transformer is less than or equal to 1; wherein Ipmax is the maximum current of the primary side, SWin is the window area of the transformer, and Scond is the sectional area of the single conductor; the primary cable and the secondary cable both use the interleaved fully shielded wire of any of claims 1-7.

10. The utility model provides an alternating full shielded wire based on heterogeneous electric current which characterized in that: the wire layer comprises a plurality of layers of wire layers which are stacked up and down, wherein each layer of wire layer is provided with a plurality of groups of corresponding wire groups in parallel, each group of wire groups comprises single-phase wires which are arranged in parallel and have the same number as the number of phases, the position of each phase of single-phase wire in the wire group in the lower layer of wire layer is shifted forward/backward by one bit compared with the position of the corresponding phase of single-phase wire in the corresponding wire group in the upper layer of wire layer, and the foremost/last single-phase wire in the wire group in the upper layer of wire layer corresponds to the rearmost/foremost single-phase wire in the corresponding wire group in the lower layer of wire layer; the position coincidence degree of a single-phase lead of a certain phase in each lead group at the upper layer in the two adjacent lead layers and a single-phase lead of the corresponding phase in each lead group at the lower layer is 0-100%.

11. The interleaved fully shielded wire of claim 10 further comprising: the conductor width of the single-phase wire is less than 2 times the skin depth.

12. The multi-phase current based interleaved fully shielded wire of claim 10 further comprising: the number of the lead groups on all the lead layers is consistent.

13. The multi-phase current based interleaved fully shielded wire of claim 10 further comprising: the number of the lead groups on the lead layer is gradually increased from the uppermost layer and the lowermost layer to the middle.

14. The multi-phase current based interleaved fully shielded wire of claim 10 further comprising: each single-phase wire comprises at least one single wire body; the conductor section of the single-phase wire is round, rectangular or regular hexagonal.

15. The multi-phase current based interleaved fully shielded wire of claim 14 further comprising: the conductor cross section of the single-phase wire is square.

16. The multi-phase current based interleaved fully shielded wire of claim 15 wherein: the conductor section of the single-phase wire satisfies that the height is larger than the width.

17. An interleaved fully shielded wire based on polyphase current according to any of claims 10-16, wherein: each layer of the lead layers is printed on a Printed Circuit Board (PCB); the distance between the single-phase wires is not more than 8 mil; the thickness of the single-phase wire is not more than 100 μm.