Dry-type transformer insulation structure

Abstract

The utility model discloses transformer insulation part technical field's including dry -type transformer body and the insulation cylinder of setting in dry -type transformer body, insulation cylinder is located between dry -type transformer body low voltage and high voltage winding, still includes: the heat dissipation channel for heat dissipation of opening in insulation cylinder, heat dissipation channel is close to low voltage winding, opening in insulation cylinder is used for the spiral gas guide groove of gas guide, and spiral gas guide groove and heat dissipation channel intercommunication form the accelerated airflow path, the ladder ring of symmetry setting in insulation cylinder end, two groups ladder ring's ladder face correspond. The utility model discloses through the staggered spiral gas guide groove on the insulation cylinder and guides the cold air to form the vortex flow, cooperate trapezoidal heat dissipation channel and discharge hot airflow fast, again combine the auxiliary heat conduction of insulation cylinder composite material, form high -efficient heat dissipation closed loop, avoid the heat and accumulate between high low voltage winding, delay the aging of insulating layer, prolong the service life of transformer.

Description

Technical Field

[0001] This utility model relates to the technical field of transformer insulation components, and in particular to an insulation structure for a dry-type transformer. Background Technology

[0002] A dry-type transformer is an electrical device that relies on air and solid materials for insulation and cooling. Its most significant characteristic is that it does not use any flammable or explosive transformer oil. Because of this, it boasts extremely high safety and environmental friendliness, fundamentally eliminating the risks of fire and leakage pollution. Furthermore, its simple structure and convenient maintenance make it an indispensable and irreplaceable core power distribution device in modern urban buildings, densely populated public places, and various indoor power supply systems.

[0003] Currently, the main insulation cylinder commonly used between high and low voltage windings in the industry is made of glass fiber reinforced epoxy resin. This insulation cylinder is made by impregnating glass fiber cloth with ordinary epoxy resin and then molding and curing it. It relies solely on the heat conduction of the cylinder wall itself to dissipate heat. However, in actual use, there are certain problems. On the one hand, the cylinder wall of some insulation cylinders does not have an effective airflow channel. The heat generated by the high and low voltage windings during operation is easy to accumulate on both sides of the cylinder wall, forming a local temperature difference of 3-5℃. Long-term operation will accelerate the aging of the main insulation cylinder and the winding insulation layer. Therefore, we urgently need a dry-type transformer insulation structure to solve the above problems. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides an insulation structure for a dry-type transformer. Through the interlaced spiral air guide grooves, trapezoidal heat dissipation channels, end stepped rings, and limiting buckles of the insulation cylinder, it achieves efficient heat dissipation, electric field homogenization, and precise positioning, solving the problems of heat accumulation and electric field concentration, and ensuring the insulation safety and service life of the transformer.

[0005] The purpose of this utility model is achieved as follows: it includes a dry-type transformer body and an insulating cylinder disposed within the dry-type transformer body, the insulating cylinder being located between the low-voltage and high-voltage windings in the dry-type transformer body, and further includes: a heat dissipation channel formed on the insulating cylinder for heat dissipation, the heat dissipation channel being close to the low-voltage winding; a spiral air guide groove formed on the insulating cylinder for air guiding, the spiral air guide groove being connected to the heat dissipation channel to form an accelerated airflow path; and stepped rings symmetrically disposed at the ends of the insulating cylinder, the stepped surfaces of the two sets of stepped rings corresponding to each other.

[0006] Optionally, the number of heat dissipation channels is at least twelve sets, and multiple sets of heat dissipation channels are arranged equidistantly in a ring along the axis of the insulating cylinder.

[0007] Optionally, the heat dissipation channel has a trapezoidal cross-section.

[0008] Optionally, the number of spiral air guide grooves is two sets, and the two sets of spiral air guide grooves are arranged alternately.

[0009] Optionally, the stepped ring is provided with three stepped surfaces.

[0010] Optionally, the dry-type transformer body is fitted with a stepped ring at a corresponding position to form an installation area.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model guides cold air to form a vortex flow through the interlaced spiral air guide grooves on the insulating cylinder, and quickly discharges hot air through the trapezoidal heat dissipation channel. Combined with the auxiliary heat conduction of the insulating cylinder composite material, a highly efficient heat dissipation closed loop is formed, which avoids heat accumulation between the high and low voltage windings, delays the aging of the insulation layer, and extends the service life of the transformer.

[0012] 2. This utility model achieves an electric field gradient transition by using three-stage stepped rings at both ends of the insulating cylinder in conjunction with a semi-conductive coating, thereby reducing the risk of local breakdown. Furthermore, the limiting buckle on the dry-type transformer body can accurately fix the position of the insulating cylinder, preventing displacement from affecting heat dissipation and electric field optimization, thus balancing insulation safety and functional stability. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of 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 only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the overall structure provided by this utility model.

[0015] Figure 2 This is a schematic diagram of the insulating cylinder structure provided by this utility model.

[0016] Figure 3 This is a cross-sectional structural diagram of the insulating cylinder provided by this utility model.

[0017] Figure 4 This is a top view schematic diagram of the insulating cylinder provided by this utility model.

[0018] In the diagram: 1. Dry-type transformer body; 2. Insulating cylinder; 3. Heat dissipation channel; 4. Spiral air guide groove; 5. Stepped ring; 6. Limiting buckle. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] like Figure 1-4 As shown in the figure, the present invention provides an insulation structure for a dry-type transformer, including a dry-type transformer body 1 and an insulating cylinder 2 disposed inside the dry-type transformer body 1. The insulating cylinder 2 is located between the low-voltage and high-voltage windings in the dry-type transformer body 1.

[0021] Here, the dry-type transformer body 1 is a direct reference to the conventional technical solution, and will not be elaborated on further. It should be noted that the insulating cylinder 2 is located between the low-voltage winding and the high-voltage winding in the dry-type transformer body 1.

[0022] Furthermore, the insulating cylinder 2 adopts a composite system of glass fiber cloth and modified epoxy resin, wherein 6-10wt% of nano-aluminum nitride particles with a particle size of 50-100nm are added to the modified epoxy resin. The temperature resistance of this material system is improved to Class H, which is 180°C, and it can withstand the winding temperature rise under high load; the thermal conductivity reaches 0.6~0.8W / m・K, enhancing the material's own thermal conductivity; the breakdown strength at 20°C is ≥20kV / mm, and the volume resistivity is ≥1×10¹. 4 Ω・cm, to ensure that the insulation strength meets the potential difference requirements between high and low voltage windings. For example, a 10kV transformer needs to withstand a power frequency withstand voltage of 12kV or higher.

[0023] It also includes heat dissipation channels 3 opened on the insulating cylinder 2 for heat dissipation. The heat dissipation channels 3 are close to the low voltage winding. The number of heat dissipation channels 3 is at least twelve. Multiple heat dissipation channels 3 are arranged in a ring at equal intervals along the axis of the insulating cylinder 2. The cross section of the heat dissipation channels 3 is trapezoidal.

[0024] Here, there are at least 12 sets of heat dissipation channels 3, which are arranged equidistantly in a ring along the axis of the insulating cylinder 2. The preferred spacing is 15 to 20 mm. For insulating cylinders 2 with a diameter of 500 to 800 mm, the spacing is 15 mm, and for insulating cylinders 2 with a diameter of 800 to 1200 mm, the spacing is 20 mm. The even distribution of multiple sets of channels can ensure balanced heat dissipation in the circumferential direction and avoid local heat accumulation.

[0025] Furthermore, the heat dissipation channel 3 has a trapezoidal cross-section. The gradually widening design from near the low-voltage winding to far away from the low-voltage winding conforms to the diffusion effect of fluid mechanics. After the airflow enters the channel, the flow rate is regulated within a reasonable range as the cross-section expands, avoiding excessive resistance due to an overly narrow cross-section. At the same time, the wider outer opening and the spiral air guide groove 4 have a larger connection area, reducing the stagnation of airflow at the corners and allowing the hot airflow to be quickly discharged through the heat dissipation channel 3.

[0026] Furthermore, the gradually widening structure extends the airflow path within the channel, allowing for a longer heat exchange time between the airflow and the channel wall. Simultaneously, the narrow inner opening can concentrate and collect hot air near the low-voltage winding, while the wide outer opening quickly discharges the heat-absorbing airflow, forming a closed loop of efficient heat absorption and rapid heat dissipation, further improving heat dissipation efficiency.

[0027] It should be noted that heat dissipation channel 3 is located close to the low-voltage winding side. Since the heat generated by the low-voltage winding is much higher than that of the high-voltage winding, a heat dissipation path can be directly constructed for the main heat source, shortening the heat transfer distance and improving heat dissipation efficiency.

[0028] Spiral air guide grooves 4 are formed on the insulating cylinder 2 for guiding air, and the spiral air guide grooves 4 are connected to the heat dissipation channel 3 to form an accelerated airflow path. There are two sets of spiral air guide grooves 4, and the two sets of spiral air guide grooves 4 are arranged alternately.

[0029] Here, there are two sets of spiral air guide grooves 4, which are staggered. The staggered spiral structure can guide the airflow to form a vortex flow. Compared with a straight groove in a single direction, it can prolong the residence time of the airflow on the low-pressure winding side, while enhancing the airflow disturbance and improving the heat exchange efficiency.

[0030] Furthermore, the spiral air guide groove 4 is directly connected to the heat dissipation channel 3, forming a three-dimensional airflow path from the spiral air guide groove 4 to the axial heat dissipation channel 3. When cold air enters from the bottom, it flows around the low-voltage winding along the spiral air guide groove 4, absorbs heat, and is quickly discharged through the axial heat dissipation channel 3 to achieve forced convection heat dissipation. In conjunction with the trapezoidal heat dissipation channel 3, the heat dissipation effect is further amplified.

[0031] The stepped rings 5 ​​are symmetrically arranged at the ends of the insulating cylinder 2. The stepped surfaces of the two sets of stepped rings 5 ​​correspond to each other, and the stepped rings 5 ​​are provided with three levels of stepped surfaces.

[0032] Here, the stepped ring 5 is provided with a three-level stepped surface, each step being 2mm high and 3mm wide. The stepped surfaces of the two sets of stepped rings 5 ​​correspond to each other. The three-level stepped design allows the electric field lines to gradually transition from the high potential at the winding end to the low potential at the insulating cylinder 2. In addition, a 0.5-1mm thick semi-conductive coating can be applied to the surface of the stepped ring 5 to further eliminate charge accumulation and homogenize the electric field distribution.

[0033] The dry-type transformer body 1 is connected to the step ring 5 at the corresponding position by the limiting buckle 6 to form an installation area.

[0034] Here, the limiting buckle 6 is made of insulating material, such as modified polyamide. After it is engaged with the stepped surface of the stepped ring 5, the coaxiality error between the insulating cylinder 2 and the dry-type transformer body 1 can be controlled to ≤0.5mm. Precise positioning can avoid insufficient local insulation thickness caused by the offset of the insulating cylinder 2, and at the same time ensure that the spiral air guide groove 4 is aligned with the winding gap, ensuring smooth airflow path and indirectly maintaining the stability of heat dissipation efficiency.

[0035] The working principle and usage process of this utility model are as follows: During operation, the heat generated by the low-voltage winding heats the surrounding air. The staggered spiral air guide grooves 4 near the low-voltage side of the insulating cylinder 2 can guide the cold air to form a vortex flow, which can fully absorb the heat of the winding. Then the hot airflow is quickly discharged through the trapezoidal heat dissipation channel 3 connected to the spiral air guide grooves 4. The trapezoidal structure can reduce airflow resistance and improve heat dissipation efficiency. The composite material of the insulating cylinder 2 can also help conduct the remaining heat and avoid heat accumulation. In response to the problem of electric field concentration at the end, the three-stage stepped rings 5 ​​at both ends of the insulating cylinder 2 form a complementary non-contact form with the winding end, providing a gradient transition path for the electric field lines. The semi-conductive coating on the surface of the stepped rings 5 ​​eliminates charge accumulation, so that the electric field intensity is evenly distributed and local breakdown is avoided. In addition, the limiting buckle 6 can accurately fix the position of the insulating cylinder 2 to prevent its displacement from affecting the airflow guidance of the spiral air guide grooves 4 or the electric field buffering effect of the stepped rings 5. At the same time, the material of the insulating cylinder 2 itself ensures the basic insulation performance between the high and low voltage windings, and finally achieves integrated operation of efficient heat dissipation, safe insulation and electric field homogenization.

[0036] The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. An insulation structure for a dry-type transformer, comprising a dry-type transformer body (1) and an insulating cylinder (2) disposed within the dry-type transformer body (1), wherein the insulating cylinder (2) is located between the low-voltage and high-voltage windings in the dry-type transformer body (1), characterized in that: Also includes: A heat dissipation channel (3) is provided on the insulating cylinder (2) for heat dissipation, and the heat dissipation channel (3) is close to the low voltage winding; A spiral air guide groove (4) is formed on the insulating cylinder (2) for guiding air, and the spiral air guide groove (4) is connected to the heat dissipation channel (3) to form an accelerated airflow path; The stepped rings (5) are symmetrically arranged at the ends of the insulating cylinder (2), and the stepped surfaces of the two sets of stepped rings (5) correspond to each other.

2. The insulation structure of a dry-type transformer according to claim 1, characterized in that: The number of heat dissipation channels (3) is at least twelve sets, and multiple sets of heat dissipation channels (3) are arranged in a ring at equal intervals along the axis of the insulating cylinder (2).

3. The insulation structure of a dry-type transformer according to claim 2, characterized in that: The heat dissipation channel (3) has a trapezoidal cross-section.

4. The insulation structure of a dry-type transformer according to claim 1, characterized in that: The number of spiral air guide grooves (4) is two sets, and the two sets of spiral air guide grooves (4) are arranged alternately.

5. The insulation structure of a dry-type transformer according to claim 1, characterized in that: The stepped ring (5) is provided with three stepped surfaces.

6. The insulation structure of a dry-type transformer according to claim 1, characterized in that: The dry-type transformer body (1) is connected to the corresponding stepped ring (5) by a limiting buckle (6) to form an installation area.

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