Ice-melting distribution transformer

Abstract

The application provides an ice-melting power distribution transformer, an ice-melting power distribution box is integrally arranged outside a transformer oil tank, a permanent magnet mechanism voltage regulating switch is connected with a low-voltage coil, ice-melting low-voltage output corresponding to a coil assembly is led out through the ice-melting power distribution box, the low-voltage coil comprises a plurality of low-voltage coil sections, including a low-voltage common coil and a plurality of low-voltage ice-melting coils, the permanent magnet mechanism voltage regulating switch comprises a switch assembly corresponding to each phase, the switch assembly comprises a plurality of voltage regulating switches corresponding to the plurality of low-voltage coil sections corresponding to phase electricity, the plurality of voltage regulating switches are one-to-one connected with the plurality of low-voltage coil sections, the low-voltage common coil supplies power for power distribution load and / or ice-melting load under corresponding phase electricity, and the low-voltage ice-melting coil supplies power for ice-melting load under corresponding phase electricity. Through the common part low-voltage coil, resource loss is avoided, the ice-melting power distribution box and the transformer mailbox are integrally designed, the space of a transformer area is saved, and the cost is reduced.

Description

Technical Field

[0001] This application relates to the field of power distribution transformer technology in electrical engineering, and in particular to a de-icing power distribution transformer. Background Technology

[0002] Due to varying regional climates and weather conditions, power grid lines may freeze under these conditions. Icing on power grid lines can cause poles to break or topple due to overload, leading to the risk of large-scale power outages. Currently, the most common method for de-icing is AC short-circuit melting to avoid such dangers.

[0003] AC short-circuit de-icing utilizes the low-voltage side voltage of the transformer at the front end of the pre-de-icing line to supply power to the distribution line that has been disconnected from the high-voltage line and short-circuited at its end. The short-circuit current heats up the distribution line, causing it to melt the ice. To improve the utilization rate of the de-icing distribution transformer, it is often designed as a three-coil type, consisting of a high-voltage coil, a low-voltage distribution coil, and a de-icing coil.

[0004] When de-icing is not required, the high-voltage and low-voltage coils supply power to the load normally. When de-icing is needed, the low-voltage coil is disconnected and the de-icing coil supplies power to the de-icing line. However, the actual de-icing distribution transformer operates for no more than 2 hours, which results in a waste of winding resources.

[0005] In addition, a dedicated de-icing distribution box needs to be designed for the protection and control of the de-icing lines. Since the inductance of the distribution lines often exceeds their resistance, large-capacity reactive power compensation devices are often installed on the de-icing distribution transformers to improve their efficiency. These de-icing distribution boxes and reactive power compensation devices require extensive wiring and occupy space in multiple distribution areas. Utility Model Content

[0006] In view of this, the purpose of this application is to provide at least one de-icing distribution transformer that avoids resource waste by sharing part of the low-voltage coil, and the integrated design of the de-icing distribution box and the transformer tank saves transformer area space and reduces costs.

[0007] This application mainly includes the following aspects: In a first aspect, embodiments of this application provide an ice-melting distribution transformer, including a permanent magnet mechanism voltage regulating switch, a core assembly corresponding to each phase, a coil assembly corresponding to each phase, a transformer tank, and an ice-melting distribution box. The core assembly includes a core and its clamps; the coil assembly includes a low-voltage coil and a high-voltage coil wound on the same core; the core assembly, coil assembly, and permanent magnet mechanism voltage regulating switch are disposed inside the transformer tank; the permanent magnet mechanism voltage regulating switch is disposed on the inner side of the transformer tank; and the ice-melting distribution box is integratedly disposed on the outer side of the transformer tank. Connected to the low-voltage coil, the low-voltage output of the coil assembly corresponding to the de-icing is led out through the de-icing distribution box. The low-voltage coil includes multiple low-voltage coil segments, including a low-voltage common coil and multiple low-voltage de-icing coil segments. The permanent magnet mechanism voltage regulating switch includes a switching assembly corresponding to each phase of electricity. The switching assembly includes multiple voltage regulating switches corresponding to the multiple low-voltage coil segments of each phase of electricity. The multiple voltage regulating switches are connected to the multiple low-voltage coil segments one by one. The low-voltage common coil supplies power to the distribution load and / or de-icing load under the corresponding phase of electricity, and the low-voltage de-icing coil supplies power to the de-icing load under the corresponding phase of electricity.

[0008] In one possible implementation, both the low-voltage coil and the high-voltage coil are foil-wound, wherein the coils in the coil assembly are distributed in the following order from the inside to the outside: multiple low-voltage de-icing coils, low-voltage common coils, and high-voltage coils.

[0009] In one possible implementation, the low-voltage coil is made of copper foil, and the corresponding lead of each low-voltage coil segment is led out from the upper and / or lower end of the entire low-voltage coil, and the corresponding lead of the high-voltage coil is led out from the upper and / or lower end of the entire high-voltage coil.

[0010] In one possible implementation, the de-icing distribution transformer achieves Class B heat resistance through the following structure: the high-voltage coil uses QZ-2 / 130 type enameled copper wire, the insulation between the coil layers corresponding to the coil assembly uses diamond-patterned DMD paper, and the oil channel support inside the coil and the main channel between the high-voltage coil and the low-voltage coil use epoxy glass cloth board.

[0011] In one possible implementation, the transformer tank is filled with high flash point transformer oil, the flash point and ignition point of which are higher than the heat resistance temperature indicated by Class B heat resistance.

[0012] In one possible implementation, the core assembly further includes a lower clamping extension bracket for the core clamp, a permanent magnet mechanism voltage regulator switch located on the low-voltage coil output side, an upper part of the permanent magnet mechanism voltage regulator switch fixed to the top cover of the transformer tank, a lower part of the permanent magnet mechanism voltage regulator switch fixed to the lower clamping extension bracket, one side of the three-phase output of the permanent magnet mechanism voltage regulator switch being close to the low-voltage coil, the other side of the permanent magnet mechanism voltage regulator switch being close to the de-icing distribution box, a portion of the three-phase output of the permanent magnet mechanism voltage regulator switch being close to the upper part of the low-voltage coil, and another portion of the three-phase output of the permanent magnet mechanism voltage regulator switch being close to the lower part of the low-voltage coil.

[0013] In one possible implementation, the de-icing distribution transformer also includes high-voltage bushings and distribution low-voltage bushings. The output wires of the high-voltage coils corresponding to the three-phase power are led out from the corresponding high-voltage bushings installed on the top cover of the transformer tank after being delta connected. The output wires of the low-voltage common coils corresponding to the three-phase power are led out from the corresponding distribution low-voltage bushings installed on the top cover of the transformer tank after being star connected.

[0014] In one possible implementation, the de-icing distribution transformer also includes a de-icing low-voltage bushing, with one side of the permanent magnet mechanism voltage regulating switch connected to the low-voltage coil terminals located at the upper and lower ends of the low-voltage coil; the other side of the permanent magnet mechanism voltage regulating switch is connected to the de-icing distribution box through the de-icing low-voltage bushing and led out from inside the de-icing distribution box.

[0015] In one possible implementation, the de-icing distribution box is equipped with a comprehensive de-icing controller, current transformers corresponding to each phase, molded case circuit breakers, and a low-voltage automatic reactive power compensation device. The current transformers include a first current transformer and a second current transformer, which are connected in series in the de-icing output circuit of the low-voltage coil of the corresponding phase. The low-voltage automatic reactive power compensation device is connected to the de-icing output circuit of the low-voltage coil of the corresponding phase. The first current transformer detects the de-icing load current and the low-voltage automatic reactive power compensation current, while the second current transformer detects the de-icing load current. The first and second current transformers are also connected to the comprehensive de-icing controller. The molded case circuit breaker is connected in series between the first and second current transformers. For each phase, the corresponding low-voltage de-icing output is sequentially led out to the de-icing load through the first current transformer, the molded case circuit breaker, and the second current transformer.

[0016] In one possible implementation, the low-voltage reactive power automatic compensation device is equipped with multiple capacitor groups connected in a given manner. Each capacitor group includes multiple capacitors connected in series. The number of capacitors connected in series in the capacitor group is determined by the maximum output voltage of the low-voltage coil of the de-icing distribution transformer and the rated terminal voltage of the capacitors.

[0017] This application provides an ice-melting distribution transformer. The core assembly includes a core and its clamps. The coil assembly includes a low-voltage coil and a high-voltage coil wound on the same core. The core assembly, coil assembly, and permanent magnet mechanism voltage regulator are located inside the transformer tank. The permanent magnet mechanism voltage regulator is located on the inner side of the transformer tank. The ice-melting distribution box is integrated on the outer side of the transformer tank. The permanent magnet mechanism voltage regulator is connected to the low-voltage coil. The low-voltage coil includes multiple low-voltage coil segments, including a common low-voltage coil and multiple low-voltage ice-melting coil segments. The permanent magnet mechanism voltage regulator includes a switch assembly corresponding to each phase. The switch assembly includes multiple voltage regulators corresponding one-to-one with the multiple low-voltage coil segments corresponding to each phase. The multiple voltage regulators are connected one-to-one to the multiple low-voltage coil segments. The common low-voltage coil supplies power to the distribution load and / or ice-melting load under the corresponding phase, and the low-voltage ice-melting coil supplies power to the ice-melting load under the corresponding phase. By sharing a portion of the low-voltage coil, resource waste is avoided. The integrated design of the ice-melting distribution box and the transformer tank saves transformer area space and reduces costs.

[0018] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This image shows one of the front views of an ice-melting power distribution transformer provided in an embodiment of this application; Figure 2 This is a second front view of an ice-melting power distribution transformer provided in an embodiment of this application; Figure 3 A side view of an ice-melting power distribution transformer provided in an embodiment of this application is shown; Figure 4 This illustration shows a schematic diagram of a low-voltage coil segmentation according to an embodiment of this application; Figure 5 A top view of a coil assembly provided in an embodiment of this application is shown; Figure 6 This illustration shows a front view of a coil assembly provided in an embodiment of this application; Figure 7 A wiring diagram of an ice-melting distribution box provided in an embodiment of this application is shown. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0022] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0023] Due to varying regional climates and weather conditions, power grid lines may freeze under these conditions. Icing can cause poles to break or topple due to overload, leading to widespread power outages. Currently, several de-icing methods exist, including manual de-icing, DC short-circuit de-icing, and AC short-circuit de-icing.

[0024] Manual de-icing is not only inefficient but also difficult to fully cover the extensive distribution network, posing high safety risks. DC short-circuit de-icing requires all transformers on the line to be de-iced to be disconnected from the grid; otherwise, the DC current may burn out the transformers connected to the line. Furthermore, de-icing can only be done by short-circuiting two phases at a time, which is inconvenient for distribution lines with numerous grid-connected transformers, many of which are three-phase lines. AC short-circuit de-icing is the most convenient method for de-icing distribution lines.

[0025] AC short-circuit de-icing utilizes the low-voltage side voltage of the transformer at the front end of the pre-de-icing line to supply power to the distribution line that has been disconnected from the high-voltage line and short-circuited at its end. The short-circuit current heats up the distribution line, causing it to melt the ice. To improve the utilization rate of the de-icing distribution transformer, it is often designed as a three-coil type: a high-voltage coil, a low-voltage distribution coil, and a de-icing coil. During normal operation without de-icing, the high-voltage and low-voltage coils supply power to the load. When de-icing is required, the de-icing coil supplies power to the load. However, in practice, the de-icing distribution transformer operates for no more than two hours, resulting in wasted winding resources. To accommodate different de-icing line lengths, the de-icing distribution transformer often has multiple voltage levels, adjusted by a motor-driven voltage regulator. The motor-driven operating mechanism has many parts, including easily damaged transmission components such as gears and cranks, thus limiting its service life and requiring maintenance. Furthermore, a dedicated de-icing distribution box is needed for the protection and control of the de-icing line. Power distribution lines often have inductance greater than resistance, so large-capacity reactive power compensation devices are often installed on the ice-melting distribution transformers to improve their efficiency. These ice-melting distribution boxes and reactive power compensation devices have many wiring connections installed on the distribution transformer area and require space in multiple transformer areas.

[0026] Based on this, this application provides an ice-melting distribution transformer. By sharing a portion of the low-voltage coil, resource waste is avoided. The integrated design of the ice-melting distribution box and the transformer fuel tank saves space in the transformer substation and reduces costs, as detailed below: Please see Figure 1 , Figure 1 This image shows one of the front views of an ice-melting distribution transformer provided in an embodiment of this application. Please refer to... Figure 2 , Figure 2 This is a second front view of an ice-melting distribution transformer provided in an embodiment of this application. Please refer to... Figure 3 , Figure 3 A side view of an ice-melting distribution transformer provided in an embodiment of this application is shown. Figures 1-3 As shown, the de-icing power distribution transformer provided in this application embodiment includes a core assembly for each phase (including a core 101, a core clamp 1011, and a lower clamp extension bracket 1012 for the core clamp), a permanent magnet mechanism voltage regulating switch 103, a coil assembly for each phase (including a low-voltage coil and a high-voltage coil wound on the same core 101), a transformer oil tank 104 (filled with high-ignition-point transformer oil), and a de-icing power distribution box 200. The transformer oil tank 104 includes a top cover and an oil tank body.

[0027] The core assembly, coil assembly 102, and permanent magnet mechanism voltage regulating switch 103 are installed inside the transformer oil tank 104. The permanent magnet mechanism voltage regulating switch 103 is installed on the inner side of the transformer oil tank 104. The de-icing distribution box 200 is integrated on the outer side of the transformer oil tank. The permanent magnet mechanism voltage regulating switch 103 is connected to the low-voltage coil corresponding to each phase. The de-icing low-voltage output corresponding to the coil assembly is led out through the de-icing distribution box 200.

[0028] The permanent magnet mechanism voltage regulator switch 103 has the characteristics of long service life and maintenance-free operation. Moreover, the permanent magnet mechanism voltage regulator switch 103 has only two states: open and closed. Therefore, based on this characteristic of the permanent magnet mechanism voltage regulator switch 103, this application divides the low-voltage coil corresponding to each phase into multiple low-voltage coil segments. The multiple low-voltage coil segments include a low-voltage common coil and multiple low-voltage de-icing coils. The permanent magnet mechanism voltage regulator switch includes a switching assembly corresponding to each phase. The switching assembly includes multiple voltage regulator switches that correspond one-to-one with the multiple low-voltage coil segments corresponding to the phase. The multiple voltage regulator switches are connected one-to-one to the multiple low-voltage coil segments. The low-voltage common coil supplies power to the distribution load and / or de-icing load under the corresponding phase. The low-voltage de-icing coil supplies power to the de-icing load under the corresponding phase.

[0029] Please see Figure 4 , Figure 4 A schematic diagram of a low-voltage coil segmentation provided in an embodiment of this application is shown. For example... Figure 4 As shown, taking phase A of a three-phase power supply as an example, the high-voltage coil corresponding to phase A is connected to the high-voltage electricity of phase A. The high-voltage input of phase A is coupled to the low-voltage coil through the corresponding battery cell. For example, the low-voltage coil is divided into four segments: x1x2, x3x4, x5x6, and x6x7. The switching components corresponding to this low-voltage coil include voltage regulating switches K1 to K4, specifically according to... Figure 4 The corresponding low-voltage coils are connected as shown. The turns ratio of the four low-voltage coil segments x1x2, x3x4, x5x6, and x6x7 is determined according to actual conditions. By opening and closing the permanent magnet mechanism switches K1 to K4, different voltages can be output at the low-voltage de-icing output terminal a1 corresponding to the low-voltage coils. Specifically, assuming that the turns ratio of the four low-voltage coil segments x1x2, x3x4, x5x6, and x6x7 is 4:3:2:1, and the corresponding outputs of the four low-voltage coil segments are 400V, 300V, 200V, and 100V respectively, the output voltage of the low-voltage de-icing output terminal a1 can be 100V, 200V, 300V, 400V, 500V, 600V, 700V, 800V, 900V, or 1000V.

[0030] The advantage of segmenting the low-voltage coil in this application is that, when the low-voltage de-icing output terminal a1 can output the above 10 voltage levels, a total of 7 low-voltage coil terminals x1 to x7 are required. In contrast, to achieve 10 output levels in the prior art, 11 terminals (one common terminal + 10 terminals corresponding to each level) need to be brought out. In other words, the prior art requires 3 more terminals to be brought out compared to this application. The low-voltage coil has a thicker wire diameter, and bringing out terminals not only increases material costs but also occupies space on top of the coil, making transformer production more difficult.

[0031] In addition, to obtain 15 voltage output levels, the design of this application only requires setting the turns ratio of the four low-voltage coils to 4:8:2:1, and the number of terminals remains unchanged at 7. In contrast, the prior art requires 16 terminals. It is evident that the design of this application has a more obvious advantage in terms of reducing material costs and minimizing the space at the top of the coil.

[0032] In addition, in order to improve the utilization rate of de-icing distribution transformers, de-icing distribution transformers are often designed as three-coil types, namely high-voltage coil, low-voltage distribution coil, and de-icing coil. When de-icing is not required, the high-voltage coil and low-voltage distribution coil are used to supply power to the load normally. When de-icing is required, the de-icing coil supplies power to the de-icing load. However, in reality, the de-icing distribution transformer does not work for more than 2 hours. During the de-icing process, the low-voltage distribution coil does not participate, resulting in a waste of winding resources.

[0033] Therefore, to solve the problem of wasted winding resources, this application extracts one low-voltage coil segment from multiple low-voltage coil segments as a common low-voltage coil, specifically as follows: Figure 4 The low-voltage common coil is x1x2. The low-voltage common coil x1x2 is designed to output a line voltage of 400V. It supplies power to the distribution load through the low-voltage distribution output terminal a2 and also serves as part of the low-voltage de-icing coil. Together with the low-voltage de-icing coils x3x4, x5x6 and x6x7, it supplies power to the de-icing load through the low-voltage de-icing output terminal a1. Here, a0 is the low-voltage output common terminal corresponding to the low-voltage coil. Even if the distribution and de-icing parts work at the same time, the transformer will only be overloaded for a short time, which can greatly avoid resource waste.

[0034] In a preferred embodiment, please refer to Figure 5 , Figure 5 A top view of a coil assembly provided in an embodiment of this application is shown. Please refer to... Figure 6 , Figure 6 A front view of a coil assembly provided in an embodiment of this application is shown. Figure 5As shown, the coil assembly adopts a foil-wound type. The coils in the coil assembly are distributed in the following order from the inside to the outside: multiple low-voltage de-icing coils, low-voltage common coils, and high-voltage coils. The purpose of this distribution order is that the distribution of the low-voltage common coils and high-voltage coils conforms to the structure of conventional distribution transformers, so that their short-circuit impedance meets the relevant national standards. If the low-voltage de-icing coils are placed in the middle position, the leakage flux width of the conventional distribution function formed by the low-voltage common coils and high-voltage coils will be too large, thereby causing the transformer's short-circuit impedance to be too large and not in compliance with the standards.

[0035] In a preferred embodiment, the low-voltage coil is made of copper foil, and the corresponding lead of each low-voltage coil segment is led out from the upper and / or lower end of the entire low-voltage coil, and the corresponding lead of the high-voltage coil is led out from the upper and / or lower end of the entire high-voltage coil.

[0036] like Figure 5 and Figure 6 The diagram also provides an example of the coil assembly corresponding to phase A input and the distribution of the lead-out positions of the two high-voltage coil input terminals A and x corresponding to phase A, and the multiple low-voltage coil terminals x1~x7 corresponding to the low-voltage coil on the coil assembly. When the low-voltage coil is wire-wound, the lead-out positions corresponding to the coil terminals are not exactly at the ends of the coil, making direct lead-out inconvenient. Therefore, the low-voltage coil of the de-icing distribution transformer is made of copper foil, so that each turn can be led out at the lower end or lower end of the low-voltage coil. Specifically, as shown in the diagram... Figures 5-6 As shown, the low-voltage coil terminals x1~x3 are led out from the top of the low-voltage coil, and the low-voltage coil terminals x4~x6 are led out from the bottom of the low-voltage coil. The high-voltage coil input terminals A and x are led out from the top and bottom of the high-voltage coil, respectively. The low-voltage coil terminal x7 is led out from the top and bottom of the low-voltage coil, respectively. Phases B and C are similar to phase A, and will not be described in detail here.

[0037] In a preferred embodiment, since the de-icing distribution transformer operates on a short-time basis, to improve the overload capacity of the transformer with the same conductor area, this application designs the distribution transformer with a conventional insulation heat resistance level of A to a heat resistance level of B: the high-voltage coil uses QZ-2 / 130 type enameled copper wire, the insulation between the coil layers corresponding to the coil assembly uses diamond-patterned DMD paper, and the oil channel support inside the coil and the main channel between the high-voltage coil and the low-voltage coil use epoxy glass cloth board.

[0038] In a preferred embodiment, the high flash point transformer oil has a flash point and a ignition point higher than the heat resistance temperature indicated by Class B heat resistance (e.g., 130 degrees Celsius).

[0039] In addition, for the low-voltage common coil in the low-voltage coil of this application, its corresponding design according to the short-time high insulation and heat resistance level can also reduce the cross-sectional area of ​​the copper coil, thereby improving the cost performance of the equipment.

[0040] In a preferred embodiment, the permanent magnet mechanism voltage regulating switch 103 preferably adopts the following... Figures 1-3 As shown, the permanent magnet mechanism voltage regulating switch 103 is located on the low-voltage coil output side, and the upper part of the permanent magnet mechanism voltage regulating switch 103 is fixed to the top cover of the transformer oil tank 104. The lower part of the permanent magnet mechanism voltage regulating switch 103 is fixed on the lower clamping expansion bracket 1012 corresponding to the iron core 101. The fixing point on the top of the transformer oil tank 104 and the fixing point on the lower clamping expansion bracket 1012 of the iron core 101 are conventional designs and will not be described in detail.

[0041] The three-phase output of the permanent magnet mechanism voltage regulator switch 103 is located on one side near the low-voltage coil, and on the other side near the de-icing distribution box 200. The three-phase output of the permanent magnet mechanism voltage regulator switch 103 is located near the upper part of the low-voltage coil, and the other part of the three-phase output of the permanent magnet mechanism voltage regulator switch 103 is located near the lower part of the low-voltage coil. The purpose of this is to minimize the wiring distance between the coil assembly, the permanent magnet mechanism voltage regulator switch 103 and the de-icing distribution box 200.

[0042] In a preferred embodiment, such as Figure 1 , Figure 3 As shown, the de-icing distribution transformer also includes a high-voltage bushing 105, a low-voltage distribution bushing 106, and a low-voltage de-icing bushing 107.

[0043] In one specific embodiment, the output line of the high-voltage coil of the de-icing distribution transformer, the A-phase coil is as follows: Figure 4 The leads from coils A and x, and similarly from coils B and C, are connected via a delta connection from... Figure 1 , Figure 3 The top cover of the transformer oil tank 104 shown is led out through the high-voltage bushing 105.

[0044] The corresponding low-voltage common coil output of A (e.g.) Figure 4 The low-voltage output terminals a2 and a0 of the low-voltage coil corresponding to phase A, and the output terminals a0 of the corresponding low-voltage common coils of phases B and C, are connected by a star connection from... Figure 1 and Figure 3 The corresponding low-voltage distribution bushing 106 is led out from the top cover of the transformer oil tank 104 shown.

[0045] The connection method of the high-voltage coil lead-out leads of the three-phase power supply in the above-mentioned delta connection method and the connection method of the low-voltage common coil lead-out leads of the three-phase power supply in the star connection method are the same as those of the conventional distribution transformer of the Dyn11 type. This part of the coil is also used as a conventional distribution transformer.

[0046] In a preferred embodiment, such as Figure 1 and Figure 2As shown, one side of the permanent magnet mechanism voltage regulating switch 103 output wire (including the output wires of each voltage regulating switch connected to the corresponding low-voltage coil terminal) is connected to the low-voltage coil terminal located at the upper and lower ends of the low-voltage coil (e.g., Figures 4-6 The diagram shows the corresponding x1~x7 phases of phase A, and the similar low-voltage coil terminals corresponding to phases B and C.

[0047] The other side of the permanent magnet mechanism voltage regulating switch 103 (including the low-voltage de-icing outputs a1, b1 and c1 corresponding to the three phases respectively) is connected to the de-icing distribution box 200 through the de-icing low-voltage bushing 107 and led out from the de-icing distribution box 200.

[0048] The de-icing distribution box 200 and the transformer oil tank 104 are designed as an integrated unit, with the shell of the de-icing distribution box 200 directly welded to the low-voltage outgoing side of the transformer oil tank 104.

[0049] In a preferred embodiment, such as Figure 2 As shown, the ice-melting distribution box 200 is equipped with an ice-melting integrated controller 201, current transformers corresponding to each phase (including a first current transformer 202 and a second current transformer 203), a molded case circuit breaker 204, and a low-voltage reactive power automatic compensation device 205.

[0050] Please see Figure 7 , Figure 7 A wiring diagram of an ice-melting distribution box according to an embodiment of this application is shown. Figure 7 As shown, taking phase A as an example, the first current transformer CT1 and the second current transformer CT2 are connected in series in the de-icing output circuit of the low-voltage coil of phase A. The low-voltage reactive power automatic compensation device 205 corresponding to phase A is connected to the de-icing output circuit of the low-voltage coil of phase A. The first current transformer CT1 corresponding to phase A detects the de-icing load current and the low-voltage reactive power automatic compensation current in the de-icing output circuit. The second current transformer CT2 corresponding to phase A detects the de-icing load current. The molded case circuit breaker 204 is connected in series between the first current transformer CT1 and the second current transformer CT2.

[0051] The corresponding first current transformer CT1 and second current transformer CT2 are also connected to the ice-melting integrated controller, so that the ice-melting integrated controller controls the permanent magnet mechanism voltage regulating switch 103 to achieve automatic voltage regulation according to the current signal collected by the second current transformer CT2, controls the low-voltage reactive power automatic compensation device 205 to automatically switch the capacitor bank according to the current signal collected by the first current transformer CT1, and controls the molded case circuit breaker QF protection to trip according to the current signals collected by CT1 and CT2.

[0052] For each phase of electricity, the corresponding low-voltage de-icing output is sequentially led out to the de-icing load through the first current transformer, the molded case circuit breaker, and the second current transformer.

[0053] The connections between the current transformers, molded case circuit breakers, and low-voltage reactive power automatic compensation devices corresponding to phases B and C are similar to those of phase A, and will not be elaborated further here.

[0054] In this application, such as Figure 7 As shown, the incoming line of the de-icing distribution box 200 is consistent with the outgoing line of the low-voltage de-icing coil (i.e., the outputs of the low-voltage de-icing coil a1, b1, and c1 serve as the incoming line of the de-icing distribution box 200). The outgoing line of the de-icing distribution box 200 is directly led out from the de-icing distribution box to connect to the corresponding de-icing load. The de-icing distribution box 200 and the low-voltage reactive power automatic compensation device 205 are integrated with the transformer tank, which saves the space in the transformer substation, reduces the continuity between the transformer and the distribution box and the low-voltage reactive power automatic compensation device, and saves costs.

[0055] In a preferred embodiment, the low-voltage reactive power automatic compensation device 205 is equipped with multiple capacitor banks (capacitor banks star-connected), which is usually designed for common voltage levels. However, the de-icing voltage output of the de-icing distribution transformer has various voltage requirements, so it usually needs to be specially customized.

[0056] The ice-melting distribution box 200 provided in this application is located on the side of the ice-melting distribution transformer, where there is ample space.

[0057] The capacitor bank is selected based on the commonly used model and the corresponding terminal voltage of the capacitors in the bank. The number of capacitors connected in series in the capacitor bank is determined by the maximum output voltage of the low-voltage coil of the de-icing distribution transformer and the rated terminal voltage of the capacitors.

[0058] For example Figure 3 The maximum output voltage corresponding to the low-voltage coil of the ice-melting distribution transformer shown is 1000V. The capacitor groups are connected in a star configuration. Therefore, select capacitors with a terminal voltage of 250V and connect them in series in 3 groups. The terminal voltage of the capacitor group formed in this way is 750V and the line voltage is about 1300V, which meets the maximum output voltage corresponding to the low-voltage coil of the transformer and leaves a voltage margin.

[0059] The benefits of this application include at least the following: (1) The ice-melting power distribution transformer provided in this application is designed with a low-voltage common coil, which allows the ice-melting process and the power distribution process to be executed simultaneously. The ice-melting function is designed with a short-time high insulation and heat resistance level, which improves the cost-effectiveness of the equipment, increases resource utilization, and avoids resource waste.

[0060] (2) The segmented low-voltage coil is adapted to the permanent magnet mechanism voltage regulator switch, which makes the equipment have a longer service life and requires no maintenance.

[0061] (3) Set the incoming line of the de-icing distribution box to be consistent with the outgoing line of the low-voltage de-icing output terminal. That is, the outgoing line of the low-voltage de-icing output terminal is directly led out from the de-icing distribution box on the side wall of the oil tank. The de-icing distribution box and the low-voltage reactive power automatic compensation device are integrated with the transformer oil tank, which saves the space of the transformer area, reduces the continuity between the transformer and the distribution box and the low-voltage reactive power automatic compensation device, and saves costs.

[0062] (4) The capacitor bank installed in the reactive power compensation device is selected according to the commonly used model and the terminal voltage is selected, thus avoiding special design and manufacturing.

[0063] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A de-icing distribution transformer, characterized in that, It includes a permanent magnet mechanism voltage regulating switch, a core assembly for each phase of electricity, a coil assembly for each phase of electricity, a transformer oil tank, and an ice-melting distribution box. The core assembly includes a core and its clamps, and the coil assembly includes a low-voltage coil and a high-voltage coil wound on the same core. The core assembly, coil assembly, and permanent magnet mechanism voltage regulating switch are located inside the transformer tank. The permanent magnet mechanism voltage regulating switch is located on the inner side of the transformer tank. The de-icing distribution box is integrated and located on the outer side of the transformer tank. The permanent magnet mechanism voltage regulating switch is connected to the low-voltage coil. The de-icing low-voltage output corresponding to the coil assembly is led out through the de-icing distribution box. The low-voltage coil includes multiple low-voltage coil segments, including a low-voltage common coil and multiple low-voltage de-icing coil segments. The permanent magnet mechanism voltage regulating switch includes a switching component corresponding to each phase of electricity. The switching component includes multiple voltage regulating switches corresponding to the multiple low-voltage coil segments corresponding to the phase of electricity. The multiple voltage regulating switches are connected to the multiple low-voltage coil segments one by one. The low-voltage common coil supplies power to the distribution load and / or de-icing load under the corresponding phase power, while the low-voltage de-icing coil supplies power to the de-icing load under the corresponding phase power.

2. The de-icing distribution transformer according to claim 1, characterized in that, Both the low-voltage and high-voltage coils are foil-wound. The coil arrangement within the coil assembly, from the inside out, is as follows: Multi-segment low-voltage de-icing coil, low-voltage common coil and high-voltage coil.

3. The de-icing distribution transformer according to claim 1, characterized in that, The low-voltage coil uses copper foil, and the corresponding lead-out wire of each low-voltage coil segment is led out from the upper and / or lower end of the entire low-voltage coil; The corresponding lead wires of the high-voltage coil are led out from the upper and / or lower ends of the entire high-voltage coil.

4. The de-icing distribution transformer according to claim 1, characterized in that, The ice-melting distribution transformer achieves Class B heat resistance through the following structure: The high-voltage coil uses QZ-2 / 130 type enameled copper wire; The insulation between the coil layers of the coil assembly is made of diamond-patterned DMD paper, and the oil channel support inside the coil and the main channel between the high-voltage coil and the low-voltage coil are made of epoxy glass cloth board.

5. The de-icing distribution transformer according to claim 1, characterized in that, The transformer oil tank contains high flash point transformer oil, the flash point and ignition point of which are higher than the heat resistance temperature indicated by Class B heat resistance.

6. The de-icing distribution transformer according to claim 1, characterized in that, The core assembly also includes a lower clamping extension bracket for the core clamp; The voltage regulating switch of the permanent magnet mechanism is located on the output side of the low-voltage coil; The upper part of the permanent magnet mechanism voltage regulating switch is fixed to the top cover of the transformer oil tank, and the lower part of the permanent magnet mechanism voltage regulating switch is fixed to the lower clamp extension bracket; One side of the three-phase output of the permanent magnet mechanism voltage regulator switch is close to the low-voltage coil, and the other side of the permanent magnet mechanism voltage regulator switch is close to the de-icing distribution box. The three-phase output part of the permanent magnet mechanism voltage regulator switch is close to the upper part of the low-voltage coil, and the other part of the three-phase output of the permanent magnet mechanism voltage regulator switch is close to the lower part of the low-voltage coil.

7. The de-icing distribution transformer according to claim 1, characterized in that, The ice-melting distribution transformer also includes high-voltage bushings and low-voltage distribution bushings; The high-voltage coils corresponding to the three-phase power supply are connected by a delta connection and then led out from the corresponding high-voltage bushings installed on the top cover of the transformer tank. The output wires of the low-voltage common coil corresponding to the three-phase power supply are star-connected and led out from the corresponding low-voltage distribution bushings installed on the top cover of the transformer tank.

8. The de-icing distribution transformer according to claim 1, characterized in that, The ice-melting distribution transformer also includes an ice-melting low-voltage bushing; One side of the permanent magnet mechanism voltage regulating switch is connected to the low-voltage coil terminals located at the upper and lower ends of the low-voltage coil. The other end of the permanent magnet mechanism voltage regulating switch is connected to the de-icing distribution box through the de-icing low-voltage bushing and led out from inside the de-icing distribution box.

9. The de-icing distribution transformer according to claim 1, characterized in that, The ice-melting distribution box is equipped with an ice-melting integrated controller, a current transformer corresponding to each phase, a molded case circuit breaker, and a low-voltage reactive power automatic compensation device. The current transformer includes a first current transformer and a second current transformer. The first current transformer and the second current transformer are connected in series in the de-icing output circuit of the low-voltage coil of the corresponding phase. The low-voltage reactive power automatic compensation device is connected to the de-icing output circuit of the low-voltage coil of the corresponding phase. The first current transformer detects the de-icing load current and the low-voltage reactive power automatic compensation current, the second current transformer detects the de-icing load current, the first current transformer and the second current transformer are also connected to the de-icing integrated controller, and the molded case circuit breaker is connected in series between the first current transformer and the second current transformer. For each phase of electricity, the corresponding low-voltage de-icing output is sequentially led out to the de-icing load through the first current transformer, the molded case circuit breaker, and the second current transformer.

10. The de-icing distribution transformer according to claim 9, characterized in that, The low-voltage reactive power automatic compensation device is equipped with multiple capacitor groups connected in a given manner, and each capacitor group includes multiple capacitors connected in series. The number of capacitors connected in series within the capacitor bank is determined by the maximum output voltage of the low-voltage coil of the de-icing distribution transformer and the rated terminal voltage of the capacitors.

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