Switching power transformer and metering device

Abstract

The utility model relates to electric power technical field provides a kind of switching power supply transformer and metering equipment, switching power supply transformer includes: transformer main body, still includes: at least two shield rings, each the shield ring includes outer shielding layer and inner insulating layer, each the shield ring is set outside the transformer main body, and at least two the shield rings are cross arrangement.The switching power supply transformer of the utility model is cross arrangement by at least two shield rings, and it is set outside transformer main body, realizes the effective shielding to constant magnetic field, and relative to the solution of traditional shield cover, the manufacturing process of shield ring is simple, cost is low, the volume of transformer main body whole is smaller, does not affect the design of circuit board in metering equipment.

Description

Technical Field

[0001] This utility model relates to the field of power technology, and in particular to a switching power supply transformer and metering equipment. Background Technology

[0002] In power systems, metering equipment is used to measure electricity consumption, and its accuracy directly affects the fairness of electricity trading and the efficiency of grid management. However, in practical applications, metering equipment may be exposed to a constant magnetic field environment. This constant magnetic field environment can interfere with the switching power supply transformer in the metering equipment, leading to inaccurate meter readings.

[0003] In existing technologies, to improve the anti-interference capability of metering equipment against constant magnetic fields and ensure measurement accuracy, a shielding cover is added to the switching power supply transformer in the metering equipment. Currently, the most widely used shielding cover solution is to use a square box capable of accommodating the switching power supply transformer to cover it. This shielding cover solution has the following disadvantages: 1. The shielding cover is complex to manufacture, which means that the finished transformer needs to go through multiple processes, making the manufacturing process complicated and costly.

[0004] 2. Since the shielding cover is usually made of high permeability alloy (such as permalloy), which is a conductor, and because the overall shielding cover is close to the primary or secondary pins of the transformer, the withstand voltage performance between the primary and secondary sides of the transformer will decrease.

[0005] 3. Adding a shield increases the size of the transformer, which will occupy a large space in the metering equipment, thus adversely affecting the PCB circuit board design. Utility Model Content

[0006] This utility model provides a switching power supply transformer and a metering device to solve the above-mentioned technical problems existing in the prior art of switching power supply transformers.

[0007] This utility model provides a switching power supply transformer, including: a transformer body, and at least two shielding rings, each of the shielding rings including an outer shielding layer and an inner insulating layer, each of the shielding rings being sleeved on the outside of the transformer body, and at least two of the shielding rings being arranged crosswise.

[0008] According to the present invention, a switching power supply transformer includes two shielding rings arranged in a cross shape.

[0009] According to the present invention, in a switching power supply transformer, the center of the cross-shaped area of ​​the two shielding rings coincides with the center of the magnetic core of the transformer body.

[0010] According to the present invention, the thickness to width ratio of the outer shielding layer is 1:10 to 1:20.

[0011] According to the present invention, the ratio of the width of the shielding ring to the minimum outer contour dimension of the magnetic core of the transformer body is greater than 1 / 3 and less than or equal to 3 / 4.

[0012] According to the present invention, the outer shielding layer of the switching power supply transformer is made of a soft conductor material.

[0013] According to the present invention, the inner insulating layer of a switching power supply transformer includes at least one layer of insulating tape.

[0014] According to the present invention, a switching power supply transformer is provided on the transformer body, wherein at least one limiting notch is provided for limiting the shielding ring.

[0015] According to the present invention, a switching power supply transformer is provided with an adhesive layer between the two intersecting shielding rings, and at the position of the intersection area.

[0016] This utility model also provides a metering device, including the switching power supply transformer described in any of the above claims.

[0017] The switching power supply transformer and metering equipment provided by this utility model have achieved effective shielding of a constant magnetic field by at least two shielding rings arranged in a cross pattern and fitted outside the transformer body. Moreover, compared with the traditional shielding cover solution, the manufacturing process of the shielding rings is simple and the cost is low. The overall volume of the transformer body is smaller and does not affect the design of the circuit board in the metering equipment. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the switching power supply transformer provided by this utility model.

[0020] Figure 2 This is an exploded structural diagram of the switching power supply transformer provided by this utility model.

[0021] Figure 3 This is a schematic diagram of the cross-region structure between the two shielding rings in the switching power supply transformer provided by this utility model.

[0022] Figure label: 1: Skeleton; 2: Winding; 3: Winding insulating tape; 4: Magnetic core; 41: First sub-core; 42: Second sub-core; 5: Inner insulation layer; 6: Outer shielding layer; 7: Limiting notch; 8: Adhesive layer. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0024] In existing related technologies, the shielding cover in a switching power supply transformer is made of a conductive material, which alters the electric field distribution. Without a shielding cover, the electric field is uniformly distributed in the insulating medium (such as air, insulating varnish, and tape) between the primary and secondary windings of the switching power supply transformer, and the withstand voltage performance is determined by the dielectric strength of the insulating material and the distance between them. With the introduction of a shielding cover, the high permeability alloy material (such as permalloy) of the shielding cover is a good conductor, forcing the electric field lines to redistribute on its surface. If the shielding cover is too close to or in contact with the pin of a certain winding (such as the primary winding), it will cause the electric field to concentrate in that area, thereby reducing the withstand voltage capability of the local insulating medium (similar to the "point discharge" effect), leading to a decrease in the withstand voltage performance between the primary and secondary windings of the switching power supply transformer. Furthermore, the shielding cover is complex to manufacture, costly, and bulky.

[0025] To solve the above technical problems, this embodiment provides a switching power supply transformer, such as... Figure 1 and 2 As shown, the transformer includes a transformer body, which typically comprises a frame 1, windings 2, and a magnetic core 4 (exemplarily, the magnetic core 4 is formed by the mating of an E-shaped first sub-core 41 and a second sub-core 42). The windings 2 are multi-layered, all wound around the frame 1, with winding insulation tape 3 provided in the middle of each layer of windings 2. To avoid interference from a constant magnetic field, the switching power supply transformer of this embodiment also includes at least two shielding rings. Each shielding ring includes an outer shielding layer 6 and an inner insulating layer 5. Each shielding ring is fitted over the transformer body, meaning that each shielding ring must cover both the windings 2 and the magnetic core 4, and at least two shielding rings are arranged crosswise. The outer shielding layer 6 is made of a conductor with high magnetic permeability, serving to shield against a constant magnetic field.

[0026] The principle behind the shielding of a constant magnetic field by the switching power supply transformer in this embodiment is as follows: Since the external interference is a constant magnetic field, which does not change with time, according to Faraday's law, a constant magnetic field cannot induce eddy currents in the two shielding rings. The outer shielding layer 6 of the two intersecting shielding rings is made of a high-permeability material (such as permalloy, amorphous / nanocrystalline alloy, electrical steel), rather than copper or aluminum. This type of material has extremely low magnetic resistance and a magnetic flux shunting effect, which can provide a "preferred path" for magnetic field lines. When the external constant magnetic field approaches, the magnetic field lines will be "attracted" by the two intersecting shielding rings with high magnetic permeability, and will preferentially flow through the material inside the two shielding rings (forming a low magnetic resistance channel), rather than passing through the transformer area inside the shielding rings. By shunting the magnetic flux, the shielding rings reduce the intensity of the interfering magnetic field entering the magnetic core 4 and winding 2 of the transformer body, protecting its normal operation from being affected.

[0027] In this embodiment, the switching power supply transformer is equipped with at least two shielding rings arranged in a cross pattern and fitted over the transformer body, which effectively shields the constant magnetic field. Moreover, compared with the traditional shielding cover solution, the manufacturing process of the shielding rings is simple and the cost is low. The overall volume of the transformer body is smaller and does not affect the design of the circuit board in the metering equipment.

[0028] Moreover, in this embodiment, the shielding ring is much smaller in volume than the shielding cover. When it is fitted outside the transformer body, it is far away from the pins of the primary or secondary winding on the transformer body. It is also provided with an inner insulating layer 5, which ensures that there is sufficient creepage distance and electrical clearance between the shielding ring and the pins of the primary or secondary winding, avoids electric field concentration in the area between the shielding ring and the pins, and thus ensures the withstand voltage performance between the primary and secondary windings of the switching power supply transformer.

[0029] In some embodiments, the switching power supply transformer includes two shielding rings arranged in a cross shape for better shielding. This cross-shaped structure, through the two orthogonal shielding rings, covers all major magnetic field interference paths. This orthogonal arrangement ensures that the shielding rings provide an effective magnetic flux shunting path regardless of the direction of the constant magnetic field (0°, 90°, or 45°, etc.), thereby achieving more effective shielding against external constant magnetic fields.

[0030] Furthermore, the center of the cross-shaped area of ​​the two shielding rings coincides with the center of the magnetic core 4 of the transformer body, meaning the cross-shaped area is directly opposite the central area of ​​the magnetic core 4. Since the central area of ​​the magnetic core 4 is a magnetic flux-sensitive area, the outer shielding layer 6 of the cross-shaped area of ​​the two shielding rings is superimposed to protect the magnetic flux-sensitive area, thereby more effectively shielding the interference of the external constant magnetic field and further reducing the impact of the external constant magnetic field on the transformer body.

[0031] In some embodiments, the thickness to width ratio of the outer shielding layer 6 is 1:10 to 1:20.

[0032] Increasing the thickness of the outer shielding layer 6 can improve the anti-saturation capability of the high magnetic permeability material; the thicker the layer, the stronger the anti-saturation capability. Increasing the width of the outer shielding layer 6 can improve its magnetic flux shunting capability, but the thicker and wider the layer, the higher the cost. Since a wider layer makes the two shielding rings closer to the structure of the shielding cover, when space is not limited, the thickness can be increased first to improve the anti-saturation capability. If space is limited, the width can be increased appropriately to improve the magnetic flux shunting capability. In this embodiment, both improving the anti-saturation capability and improving the magnetic flux shunting capability can effectively improve the anti-interference capability of the constant magnetic field. Considering space, cost, and anti-interference capability, the thickness to width ratio of the outer shielding layer 6 is 1:10 to 1:20.

[0033] In some embodiments, such as Figure 1 As shown, the ratio of the width W1 of the shielding ring to the minimum outer contour dimension W2 of the magnetic core 4 of the transformer body is greater than 1 / 3 and less than or equal to 3 / 4. A W1 / W2 ratio greater than 1 / 3 ensures good resistance to constant magnetic field interference, while a W1 / W2 ratio less than or equal to 3 / 4 prevents the structures of the two shielding rings from being too close to the shielding cover. The outer contour of the magnetic core 4 is typically rectangular or circular. When the magnetic core 4 is rectangular, the minimum outer contour dimension W2 is the width; when the magnetic core 4 is circular, the minimum outer contour dimension W2 is the diameter.

[0034] Since the two shielding rings are fitted onto the outside of the transformer body, in some embodiments, the outer shielding layer 6 is made of a soft conductive material (e.g., permalloy, amorphous / nanocrystalline alloy, etc.) to better secure the two shielding rings to the outside of the transformer body. The soft conductive material has a certain degree of elasticity, which allows the shielding rings to be firmly secured to the outside of the transformer body.

[0035] In some embodiments, the inner insulating layer 5 includes at least one layer of insulating tape. The insulating tape is low in cost and can be directly adhered to the outer shielding layer 6, simplifying the manufacturing process of the shielding ring. Furthermore, the outer shielding layer 6 also has an outer insulating layer (not shown in the figure), which can be a layer of insulating tape to ensure that the transformer body has good insulation performance from the outside world.

[0036] In some embodiments, the transformer body is provided with at least one limiting notch 7 for limiting the shielding ring. For example, the limiting notch 7 can be provided on the frame 1, and the width of the limiting notch 7 can match the width of the shielding ring. After the shielding ring is installed, it is locked in the limiting notch 7, which can better fix the shielding ring and prevent its lateral movement. Furthermore, the limiting notch 7 can be positioned at the center region of the corresponding magnetic core 4. After the two shielding rings are installed, the intersection area of ​​the two shielding rings corresponds exactly to the center region of the magnetic core 4, thereby achieving rapid positioning and installation of the shielding ring.

[0037] In some embodiments, such as Figure 3 As shown, an adhesive layer 8 (e.g., an adhesive layer) is provided between the two shielding rings, at the intersection area. After the two shielding rings are installed in place, the two shielding rings are glued together by the adhesive layer 8, thereby better fixing the shielding rings and preventing them from moving.

[0038] This utility model also provides a metering device, including the switching power supply transformer described in any of the above embodiments. The metering device can be an energy meter or a data acquisition terminal, among other devices. Because it employs the switching power supply transformer described in the above embodiments, the metering device can achieve accurate measurement even under interference from an external constant magnetic field.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A switching power supply transformer, comprising: The transformer body is characterized in that it further includes: at least two shielding rings, each of the shielding rings including an outer shielding layer and an inner insulating layer, each of the shielding rings being sleeved on the outside of the transformer body, and at least two of the shielding rings being arranged crosswise.

2. The switching power supply transformer according to claim 1, characterized in that, It includes two shielding rings, which are arranged in a cross shape.

3. The switching power supply transformer according to claim 2, characterized in that, The center of the cross-shaped area of ​​the two shielding rings coincides with the center of the magnetic core of the transformer body.

4. The switching power supply transformer according to claim 1, characterized in that, The thickness to width ratio of the outer shielding layer is 1:10 to 1:

20.

5. The switching power supply transformer according to claim 1, characterized in that, The ratio of the width of the shielding ring to the minimum outer contour dimension of the magnetic core of the transformer body is greater than 1 / 3 and less than or equal to 3 / 4.

6. The switching power supply transformer according to any one of claims 1 to 5, characterized in that, The outer shielding layer is made of a soft conductive material.

7. The switching power supply transformer according to any one of claims 1 to 5, characterized in that, The inner insulating layer includes at least one layer of insulating tape.

8. The switching power supply transformer according to any one of claims 1 to 5, characterized in that, The transformer body is provided with at least one limiting notch for limiting the shielding ring.

9. The switching power supply transformer according to any one of claims 1 to 5, characterized in that, An adhesive layer is provided between the two intersecting shielding rings, and at the location of the intersection area.

10. A measuring device, characterized in that, Including the switching power supply transformer as described in any one of claims 1 to 9.

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