TWI640022B - Induction type power supply system and coil module thereof - Google Patents

Abstract

A coil module is used in an inductive power supply system. The coil module includes a support frame, an upper cover and a first wire. The upper cover is disposed on the support frame, and the upper cover is provided with a spiral groove. The first wire is inserted into the spiral groove to form a coil.

Description

Inductive power supply system and coil module

The invention relates to an inductive power supply system and a coil module thereof, and more particularly to an inductive power supply system and a coil module thereof having good electromagnetic induction performance.

Traditionally, the coil of an inductive power supply is wound by a wire and bonded to form a flat spiral, such as the coil winding method disclosed in the Republic of China Patent Publication No. 201523661. Under the traditional coil winding method, the energy transmission is relatively concentrated. When the induction surface of the power supply coil and the power receiving coil are completely aligned, the energy transmission efficiency is extremely high. However, as long as the power supply coil and the power receiving coil are slightly displaced, the energy transmission efficiency is Rapid decline, the corresponding relationship between energy transmission efficiency and position shift is shown in Figure 1A.

In recent years, inductive power supplies have been widely used in wireless charging systems for automatic guided vehicles. Because automatic guided vehicles often have path errors when they move, their positions at charging stations cannot be fixed. In this case, when the power supply terminal sends the same energy, the power receiving device on the automatic transport vehicle may receive different sizes of power power according to different positions, and the degree of deviation of the power receiving coil relative to the power supply coil will be Significantly affect the amount of power it receives.

In addition, if the power supply coil cannot be aligned with the power receiving coil when power is supplied, part of the energy emitted by the power supply coil will not be transmitted to the power receiving end, but will be transmitted to the air or to the device behind the power receiving coil, causing electromagnetic interference (Electromagnetic Interference, EMI). )The problem. In view of this, it is necessary to propose a novel coil structure in order to improve the problem of the large decrease in power supply efficiency caused by position shift and excessive electromagnetic interference.

Therefore, the main object of the present invention is to provide an inductive power supply system and a coil module thereof, in which a coil is formed by a wire arranged in a spiral groove, and the power supply coil and the power receiving coil can adopt different winding forms. And they are staggered from each other to avoid a large change in the energy transmission efficiency between the coil position alignment and the offset.

The present invention discloses a coil module for an inductive power supply system. The coil module includes a support frame, an upper cover and a first wire. The upper cover is disposed on the support frame and is provided with a spiral groove. The first wire is inserted into the spiral groove to form a coil.

The invention further discloses an inductive power supply system including a first coil module and a second coil module. The first coil module can be used for a power supply end of the inductive power supply system. The first coil module includes a support frame, an upper cover and a first wire. The upper cover is disposed on the support frame and is provided with a first spiral groove. The first wire is inserted into the first spiral groove to form a power supply coil. The second coil module can be used for a power receiving end of the inductive power supply system. The second coil module includes a support frame, an upper cover and a second wire. The upper cover is disposed on the support frame and is provided with a second spiral groove. The second wire is inserted into the second spiral groove to form a power receiving coil.

As described above, for conventional coils, when the coil position is shifted, the energy transmission efficiency is greatly reduced. In order to realize the wireless charging application of the automatic guided vehicle, the present invention adopts a novel coil structure, which can realize the correspondence relationship between the energy transmission efficiency and the position shift as shown in FIG. 1B. In this way, the coil position deviation will not cause excessive changes in energy transmission efficiency. At the same time, as long as the power receiving coil module of the automatic truck is close to the power supply coil module of the charging station, the two do not need to be completely aligned to generate a good power effectiveness.

Please refer to FIG. 2, which is a schematic diagram of a coil module 20 according to an embodiment of the present invention. As shown in FIG. 2, the coil module 20 includes a support frame 200 and an upper cover 202. The support frame 200 may be made of metal (such as aluminum), which can be used as the main structure of the coil module 20 to support various components in the coil module 20, and has functions such as heat dissipation and waterproof. At the same time, the support frame 200 should have Sturdy and impact-resistant material, able to withstand the impact of automatic trucks. The upper cover 202 may be disposed on the support frame 200 to shield the components on the support frame 200 and provide waterproofing.

Please refer to FIG. 3, which illustrates an embodiment of the upper cover 202 in FIG. 2. In detail, the upper cover 202 is provided with a spiral groove for setting a wire. The coil module 20 may further include a conductive wire, and the conductive wire is inserted into the spiral groove to form a coil. In addition, in order to prevent the coil energy from being transmitted to the metal of the support frame 200 to generate heat, the coil module 20 may further include a magnetic conductor (not shown) disposed between the upper cover 202 and the support frame 200 (ie, the coil and the support frame 200). Between), used to isolate the electromagnetic energy of the coil. The magnetic conductor also has the function of heat conduction, which can transfer the thermal energy generated on the coil when the current passes through the coil to the metal frame for heat dissipation. The magnetic conductor can be composed of magnetic materials with high permeability characteristics, such as Mn-Zn Core, Ni-Zn Core, Iron Powder Core, Iron-Ni-Mo magnet Core (Molypermalloy Powder (MPP) Core), ferrosilicon aluminum core (Sendust Core), ferrite core (Ferrite Core), high flux core (High Flux Core) or other equivalent magnetic materials.

It is worth noting that, in order to achieve effective space utilization, the shape of the spiral groove can be set according to the shape of the upper cover. Taking the embodiment of FIG. 3 as an example, the shape of the upper cover 202 is a square including a notch. Therefore, the shape of the groove is a square spiral shape, and the four corners of the square are modified into an arc shape, which makes the coil easy to turn. Since the shapes of the upper cover 202 and the spiral groove are both approximately square, the arrangement of the grooves can effectively utilize the area of the upper cover 202. In other words, the groove can be covered with the available portion of the upper cover 202. In other embodiments, other shapes of spiral grooves may be used. For example, if the upper cover is circular, a circular spiral groove may be provided on the upper cover; if the upper cover is triangular, a triangular spiral groove may be provided on the upper cover. The three corners of the slot and the triangle can also be modified into an arc shape to make the coil easy to turn. In this way, the present invention can effectively utilize the space of the cover. In comparison, traditional coils are formed by gluing, which must be round, and often the space cannot be effectively used when the upper cover is not round.

In addition, there are many different ways to arrange the wires in the spiral groove. In one embodiment, an opening may be provided between two adjacent layers in the spiral groove. Please refer to FIG. 4, which is a schematic diagram of a coil 400 disposed in a spiral groove 402 according to an embodiment of the present invention. It is assumed that the outermost layer of the spiral groove 402 is the first layer, and the number of each layer is as shown in FIG. 4. Above the center of the spiral groove 402, openings 404 are provided between the fifth layer and the sixth layer, between the sixth layer and the seventh layer, ..., up to the innermost layer. Each opening 404 is connected between two adjacent layers to form a passage through which a wire can pass. As shown in FIG. 4, the coil 400 is arranged in such a manner that the wires are arranged along the groove from the first layer (the outermost layer) until the fifth layer connects to the opening 404 of the sixth layer, and directly enters the sixth through the opening 404. Layer without filling the fifth layer; then, at the seventh layer connecting the opening of the eighth layer 404, directly enter the eighth layer through the opening 404 without filling the seventh layer; connecting the opening of the tenth layer at the ninth layer At 404, the 10th layer is directly entered through the opening 404 without filling the 9th layer. It should be noted that the above-mentioned wire arrangement is described based on the way from the outside to the inside, but the wire arrangement of the present invention should not be limited to this, for example, it can be set from the inside to the outside. In an embodiment, the conductive line can also be completely filled into the fifth layer of the spiral groove 402, and then enter the seventh layer from the sixth layer through the opening 404. Alternatively, the wire can pass through two or more layers through the opening 404, for example, from the fifth layer to the seventh layer through the opening 404, or from the sixth layer to the ninth layer through the opening 404. In one embodiment, the wire can also be wound directly along each layer of the spiral groove 402 without passing through any opening to form a coil. In addition, openings can also be provided between the first to fifth layers of the spiral groove to improve the flexibility of the wire arrangement, as shown in Figure 5.

On the other hand, the number of wires to be placed in the trench should not be a limitation of the present invention. For example, in FIG. 4, the coil 400 is formed by inserting two insulated wires into the spiral groove 402. Preferably, the ability to transmit a modulation signal can be added to one of the wires, while the other wire is only used for power transmission without performing signal modulation / demodulation operation. In other words, the signal modulation circuit or the signal demodulation circuit is only connected to one of the wires, so that the modulation signal is transmitted only on the wire, which can reduce the influence of the signal modulation / demodulation operation on the power transmission performance. In another embodiment, more than two wires can be placed in the spiral groove 402 to form a coil, and the signal modulation / demodulation operation can be set to be performed on one of the wires. In another embodiment, the characteristics of the wire used for signal modulation / demodulation operation can also be adjusted. For example, a thinner wire or a wire with fewer cores is used as a coil for signal modulation / demodulation to modulate the signal. The effect of demodulation operation on power transmission performance is minimized. In addition, the signal modulation circuit or signal demodulation circuit can only be connected to a single end of the coil (such as the innermost pull-out end), so that the modulation signal is concentrated in the area near the inner circle of the coil, which can further improve the signal transmission and analysis capabilities.

As described above, the coils of the conventional inductive power supply are wound and bonded to form a planar spiral shape, and the energy transmission efficiency of the coils is greatly reduced as the coil position shifts. In addition, if the power supply coil cannot be aligned with the power receiving coil during power supply, the problem of excessive electromagnetic interference (EMI) is likely to occur. In contrast, the coil of the present invention is formed by placing a wire into a spiral groove located on the upper cover, and the above problem can be solved by the way of placing the wire in the groove. In detail, the method of providing a spiral groove on the upper cover and providing an opening in the spiral groove and forming a coil by placing a wire in the spiral groove can be used for both the power supply end (ie, the power supply coil) and the power receiving end (ie, the power receiving Coil). According to different applications, the shape of the wire in the spiral coil can be designed to be the same as or different from the shape of the wire in the spiral coil.

In one embodiment, the outermost length of the power supply coil can be designed to be shorter than the outermost length of the power receiving coil. Please refer to FIGS. 6A and 6B, which are schematic diagrams of a power supply coil 600 and a power receiving coil 610 according to an embodiment of the present invention, respectively. Similarly, it is assumed that the outermost layer of the spiral groove is the first layer and the innermost layer is the twelfth layer, and the number of each layer is as shown in FIGS. 6A and 6B. It can be seen from FIG. 6A that in the spiral groove of the power supply coil 600, the outermost layer provided with the wire is the third layer; from FIG. 6B, it is known that the outermost layer provided with the wire in the spiral groove of the power receiving coil 610 is Level 1. In this case, the length of the outermost ring (on the third layer) of the power supply coil 600 is shorter than the length of the outermost ring (on the first layer) of the power receiving coil 610. At this time, the entire area of the power receiving coil 610 is larger than that of the power supply coil 600. Overall area. When the position of the coil is shifted, as long as the magnitude of the shift does not exceed the area of the power receiving coil 610, the energy emitted by the power supply coil 600 will not exceed the range that the power receiving coil 610 can receive, thereby reducing electromagnetic interference.

It is worth noting that the above method of setting the entire area of the power supply coil to be smaller than the entire area of the power receiving coil may cause the number of turns of the power receiving coil to be greater than the number of turns of the power supply coil. According to the principle of the transformer, the output / input voltage ratio is equal to the ratio of the output coil and the input coil. Therefore, if the number of turns of the power receiving coil is greater than the number of turns of the power supply coil, the voltage received by the power receiving end is likely to be too high, which increases the difficulty of voltage control. Ideally, if the number of turns of the power receiving coil is equal to the number of turns of the power supply coil, the output voltage of the power receiving end can be controlled to be approximately equal to the input voltage of the power supply end, or the number of turns of the power receiving coil can be set close to the number of turns of the power supply coil. In order to control the size of the output voltage. In this case, the number of turns filled in the spiral groove of the power supply coil 600 can be set equal to or close to the number of turns filled in the spiral groove of the power receiving coil 610, thereby effectively controlling the output voltage. Taking the coils in Figures 6A and 6B as an example, the arrangement of the power supply coil 600 and the power receiving coil 610 can be expressed in Table 1: Table 1

Referring to Table 1 with Figures 6A and 6B, it can be seen that the power supply coil 600 passes through the opening in the spiral groove at the positions of the sixth layer and the eighth layer, respectively, and the outermost circle of the power supply coil 600 is located at the third layer of the spiral groove. Therefore, the power supply coil 600 includes a total of eight turns; the power receiving coil 610 passes through the opening in the spiral groove at the positions of the fifth layer, the seventh layer, and the ninth layer. Therefore, the power receiving coil 610 includes a total of nine turns. In this case, the number of turns of the power supply coil 600 and the power receiving coil 610 is close, which can effectively control the output voltage of the power receiving end.

In addition, the power supply coil 600 and the power receiving coil 610 pass through the openings in the spiral grooves at different positions, respectively, so that the position of the conductive wire in the power supply coil 600 and the position of the conductive wire in the power receiving coil 610 are partially staggered. . In this case, even when the power-supply coil 600 and the power-receiving coil 610 are completely aligned, the wires on the two coils will not completely overlap, which can avoid a situation in which the energy transmission efficiency is too large when the coils are aligned. In this way, the coil offsets within a certain range all have similar energy transmission efficiency, which can produce the ideal situation shown in FIG. 1B, thereby improving the disadvantage of the conventional technology that the coil offset causes a significant reduction in energy transmission efficiency.

Generally speaking, the energy distribution on the coil is the strongest energy at both ends of the wire and the weakest energy in the middle section. In the traditional coil winding method, the wires are formed by a lamination method, so the density of the wires at the two ends and the middle of the coil is necessarily the same. If you want to increase the output energy of the coil, you can only do so by increasing the number of coil turns, but with the concomitant increase in the length of the wire, the parasitic impedance increases. In contrast, in the embodiment of the present invention, the coil is formed by inserting the wire into the spiral groove, and there is a gap between the wire and the wire. Under the same coil area, a smaller parasitic impedance can be generated (due to the wire Shorter length). If you want to improve the efficiency of energy transmission, you can design the wire through the spiral groove in the middle of the coil to make more openings, so that the density of the wire in the middle of the coil is lower than the density of the wires at the two ends of the coil, as shown in the coil arrangement in Figure 6A and 6B. In this way, the length of the wire can be reduced at the middle position where the energy is weak, thereby reducing the parasitic impedance and improving the energy transmission efficiency.

It is worth noting that the present invention provides an inductive power supply system and a coil module thereof, which can be provided with a groove on the upper cover and a wire can be inserted into the groove to form a coil. Those skilled in the art can make modifications or changes based on this, without being limited thereto. For example, the spiral groove can be set in any way according to the system requirements, for example, an opening can be provided at any position to pass the wire. In addition, the above embodiments are designed to pass more openings in the middle of the coil to reduce the density of the wire in the middle of the coil, but in other embodiments, the density of the wire can also be adjusted by setting the spiral groove, such as the position of the middle of the coil Trenches with lower density are set (that is, the distance between layers is larger), and trenches with higher density are set on the sides of the coil (that is, the distance between layers is smaller). In addition, the inductive power supply system and the coil module of the present invention are applicable to a wireless charging system of an automatic truck, which can improve the problem that the positional deviation of the automatic truck causes a significant decrease in power supply efficiency. However, the application of the automatic transport vehicle should not be a limitation of the present invention. In other words, the inductive power supply system and the coil module of the present invention can also be used in other types of wireless charging systems, such as desktop wireless for mobile devices. Charger or charger for electric vehicles.

In summary, in the inductive power supply system and the coil module of the present invention, the coil is arranged by forming a spiral groove on the upper cover and inserting a wire into the groove. Compared with the traditional coil formed by bonding wires after being wound, the coil setting method of the present invention has greater flexibility, which can improve many problems in the conventional technology. Wherein, an opening may be provided between two adjacent layers of the spiral groove, and the wire may enter the next layer through the opening to reduce the length of the wire on the coil, thereby reducing parasitic impedance. In addition, the power supply coil and the power receiving coil can adopt different wire arrangement forms. In an embodiment, the length of the outermost circle of the power supply coil is smaller than the length of the outermost circle of the power receiving coil, so that the entire area of the power receiving coil is larger than the entire area of the power supply coil, so as to prevent the power supply coil from transmitting when the coil position is offset. The energy is beyond the range that the power receiving coil can receive, thereby reducing electromagnetic interference. In one embodiment, the number of turns of the power receiving coil can be set equal to or close to the number of turns of the power supply coil, so as to effectively control the output voltage of the power receiving end. In an embodiment, the power supply coil and the power receiving coil respectively pass through the openings in the spiral groove at different positions, so that the position of the wire in the power supply coil and the position of the wire in the power receiving coil are partially staggered, thereby avoiding When the coils are aligned, the energy transmission efficiency is too large, which can improve the disadvantage that the coil offset causes the energy transmission efficiency to be greatly reduced. In addition, the wire can be designed to have more openings in the spiral groove in the middle of the coil, so that the density of the wire in the middle of the coil is lower than the density of the wire at both ends of the coil, thereby reducing parasitic impedance and improving overall energy transmission efficiency. In this way, the present invention can greatly improve the performance of the inductive power supply system and the coil module by setting the spiral groove and adopting a suitable wire setting method. The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the scope of patent application of the present invention shall fall within the scope of the present invention.

20‧‧‧coil module
200‧‧‧ support
202‧‧‧ Upper cover
400‧‧‧coil
402‧‧‧spiral groove
404‧‧‧ opening
600‧‧‧Power supply coil
610‧‧‧Power receiving coil

FIG. 1A is a schematic diagram of the correspondence relationship between the energy transmission efficiency and position shift of a conventional coil. FIG. 1B is a schematic diagram of a correspondence relationship between energy transmission efficiency and position shift according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a coil module according to an embodiment of the present invention. FIG. 3 illustrates an embodiment of the upper cover in FIG. 2. FIG. 4 is a schematic diagram of a coil disposed in a spiral groove according to a first embodiment of the present invention. FIG. 5 is a schematic diagram of a spiral groove according to an embodiment of the present invention. 6A and 6B are schematic diagrams of a power supply coil and a power receiving coil according to an embodiment of the present invention, respectively.

Claims (11)

A coil module for an inductive power supply system. The coil module includes: a support frame; an upper cover provided on the support frame; a spiral groove is provided inside the upper cover; and a first wire, The spiral groove is inserted to form a coil; wherein an opening is provided between the Nth layer and the N + 1th layer of the spiral groove. The coil module according to claim 1, further comprising: a magnetic conductor disposed between the coil and the support frame to isolate electromagnetic energy of the coil. The coil module according to claim 1, wherein the arrangement of the first wire is from the Nth layer to the N + 1th layer through the opening without filling the Nth layer. The coil module according to claim 1, wherein the shape of the spiral groove is set according to the shape of the upper cover. The coil module according to claim 1, wherein the spiral groove is provided with a second wire, the second wire is insulated from the first wire, and the signal modulation or demodulation operation is performed only on the first wire and the first wire. One of the two wires is performed, and the other is used only for power transmission without signal modulation or demodulation operation. The coil module according to claim 1, wherein a density of a wire in a middle section of the coil is lower than a density of a wire in both ends of the coil. An inductive power supply system includes: a first coil module for a power supply end of the inductive power supply system; the first coil module includes: a support frame; an upper cover provided on the support On the rack, a first spiral groove is provided inside the upper cover; and a first wire is inserted into the first spiral groove to form a power supply coil; a second coil module is used in the inductive power supply system A power receiving end, the second coil module includes: a support frame; an upper cover is disposed on the support frame, a second spiral groove is provided inside the upper cover; and a second wire is inserted into the second spiral The first conductive wire is inserted into the first spiral groove, and the second conductive wire is inserted into the second spiral groove. The inductive power supply system according to claim 7, wherein a first opening is provided between the Mth layer and the M + 1th layer of the first spiral groove, and the Nth layer of the second spiral groove and the A second opening is disposed between the N + 1th layer. The inductive power supply system according to claim 8, wherein the setting of the first wire is from the Mth layer to the M + 1th layer through the first opening, and the Mth layer is not filled, and the second wire is not filled. The arrangement of is from the Nth layer to the N + 1th layer through the second opening without filling the Nth layer. The inductive power supply system according to claim 7, wherein a length of an outermost circle of the power supply coil is smaller than a length of an outermost circle of the power receiving coil. The inductive power supply system according to claim 7, wherein when the first wire is inserted into the first spiral groove and the second wire is inserted into the second spiral groove, the first spiral groove is filled with The number of turns full of the first wire is equal to or close to the number of turns full of the second wire in the second spiral groove.