Metal armored high-voltage voltage transformer for motor train unit

Abstract

The invention relates to a high-voltage measuring device for an electric power system of a motor train unit, in particular to a metal armored high-voltage voltage transformer for the motor train unit. Comprising an insulator and a coil device body sealed in the insulator, a primary high-voltage insulating sleeve is arranged on the top or the upper side portion of the insulator, and a primary high-voltage terminal and a shielding net surrounding the primary high-voltage terminal are arranged in the primary high-voltage insulating sleeve; a secondary terminal is arranged at the lower part of the insulator; a metal shell is arranged outside the insulator, and a semi-conductive layer is sprayed on the surface, located inside the metal shell, of the insulator. According to the invention, the epoxy resin and the metal shell form a totally-enclosed dry-type structure, and the primary shielding lead is used in cooperation, so that the problem of an original exposed high-voltage lead on a motor train unit is solved, the voltage condition can be monitored in real time, and the safety of the train in the running process is ensured; moreover, the system can adapt to a complex operation environment, and prevents the motor train unit from being affected by factors such as electromagnetic interference and temperature change in the operation process.

Description

Technical Field

[0001] This invention relates to a high-voltage measuring device for the power system of high-speed trains, specifically a metal-clad high-voltage voltage transformer for high-speed trains. Background Technology

[0002] With the continuous development of China's high-speed rail technology, the requirements for the safety and reliability of high-speed trains are becoming increasingly stringent. Voltage transformers, as one of the key pieces of equipment in the power system of high-speed trains, not only monitor voltage conditions in real time to ensure train safety during operation, but also adapt to complex operating environments, preventing the high-speed train from being affected by electromagnetic interference, temperature changes, and other factors during operation. In recent years, voltage transformers with C-type head European bushing connections still suffer from problems such as exposed high-voltage conductors, difficulty in shielding, and poor anti-interference capabilities. Therefore, there is an urgent need for a metal-clad high-voltage voltage transformer for high-speed trains that is small in size, simple in structure, has strong anti-interference capabilities, superior protection performance, high operational safety, and is suitable for various environments such as high and low altitudes and high humidity. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide a metal-clad high-voltage voltage transformer for high-speed trains, thereby solving the problems of exposed high-voltage wires, difficulty in shielding, and poor anti-interference capability in existing high-voltage voltage transformers for high-speed trains.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention provides a metal-clad high-voltage voltage transformer for high-speed trains, comprising an insulator and a coil body encased within the insulator. A primary high-voltage insulating bushing is provided on the top or upper side of the insulator, and a primary high-voltage terminal and a shielding mesh surrounding the primary high-voltage terminal are provided inside the primary high-voltage insulating bushing. A secondary terminal is provided at the lower part of the insulator. A metal shell is provided on the outer side of the insulator, and a semi-conductive layer is sprayed on the surface of the insulator located inside the metal shell. The semi-conductive layer is in contact with the metal shell and conducts electricity.

[0006] The shielding mesh consists of a ring-shaped metal wire mesh with symmetrically arranged embedded nuts. The outer surfaces of the ring-shaped metal wire mesh and the embedded nuts are uniformly coated with a layer of semi-conductive paint, and the embedded nuts are embedded in the insulator.

[0007] The secondary terminals include input secondary terminals and output secondary terminals, and a secondary fuse is provided on the line connected to the input secondary terminals.

[0008] The secondary terminal is enclosed by the protruding portion of the metal casing and then sealed by the secondary terminal cover plate. The protruding portion of the metal casing is provided with a waterproof cable connector for connecting to the secondary terminal.

[0009] The primary high-voltage insulating bushing and the insulator are integrally formed by epoxy resin casting.

[0010] The primary high-voltage insulating bushing has a tapered structure.

[0011] The insulator has a cuboid structure, and the top, left and right sides of the front and rear are provided with transition slopes.

[0012] The coil body includes an iron core, a secondary winding, and a primary winding. The secondary winding and the primary winding are concentrically wound from the inside out on an insulating frame and then fitted onto the core post of the iron core 1. The primary lead of the primary winding is connected to the primary high-voltage terminal, and the secondary lead of the secondary winding is connected to the secondary terminal.

[0013] The insulator is mounted on the base plate, which is connected to the EMU. The primary high-voltage insulating bushing is connected to the primary connecting cable on the EMU.

[0014] The present invention has the following advantages and beneficial effects:

[0015] This invention utilizes a fully enclosed dry structure composed of epoxy resin and a metal shell, combined with primary shielded conductors, to solve the problem of previously exposed high-voltage conductors on high-speed trains. It not only enables real-time voltage monitoring to ensure train safety during operation, but also adapts to complex operating environments, avoiding the impact of electromagnetic interference, temperature changes, and other factors on the high-speed train during operation. Its main advantages include:

[0016] 1. Small size, flexible installation, and anti-interference: The metal-armored current transformer with C-type head and high-voltage shielded cable has no exposed high-voltage wires, so the installation is not limited by space. It has excellent protection performance and effectively shields the influence of external electromagnetic interference on the current transformer.

[0017] 2. Uniform internal and external electric field, safe to touch while charged, and protective casing: The metal casing design and the semi-conductive layer between the inner surface of the metal casing and the resin body ensure a uniform internal and external electric field, allowing for safer operation and higher reliability, even in harsh environments. The metal casing can withstand significant pressure, protecting the internal structure and the external vehicle body. Even if the current transformer fails, it will not affect external equipment.

[0018] 3. Leakage prevention, full shielding, and strong anti-interference ability: The high-voltage primary terminal shielding mesh and the metal shell are connected by a semi-conductive layer, resulting in better full shielding and stronger anti-interference ability. This eliminates leakage discharge of the primary high voltage to the outside, further enhancing the safety of the touchable surface.

[0019] 4. Strong protection performance and overcurrent protection: The metal casing combined with the metal waterproof connector ensures that the secondary terminals are not affected by dust and moisture; the secondary fuse is added to prevent secondary overcurrent from affecting the transformer. This ensures that the transformer is not burned out and provides secondary overcurrent protection during product operation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the internal structure and matching cable interface of the metal-armored high-voltage voltage transformer for high-speed trains of the present invention.

[0021] Figure 2 This is a front view of the metal-clad high-voltage voltage transformer for high-speed trains according to the present invention.

[0022] Figure 3 This is a top view of the metal-clad high-voltage voltage transformer for high-speed trains according to the present invention.

[0023] In the diagram: 1-Iron core, 2-Secondary winding, 3-Primary winding, 4-Primary high-voltage insulating bushing, 5-Primary high-voltage terminal, 6-Shielding mesh, 7-Insulator, 8-Metal shell, 9-Semi-conductive layer, 10-Cable waterproof connector, 11-Secondary terminal cover, 12-Input secondary terminal, 13-Output secondary terminal, 14-Secondary fuse, 15-Base plate, 16-Primary connection cable. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] like Figures 1 to 3 As shown, the present invention provides a metal-armored high-voltage voltage transformer for high-speed trains, comprising an insulator 7 and a coil body enclosed within the insulator 7. The top or upper side of the insulator 7 is provided with a primary high-voltage insulating sleeve 4, and a primary high-voltage terminal and a shielding mesh 6 surrounding the primary high-voltage terminal 5 are provided inside the primary high-voltage insulating sleeve 4. A secondary terminal is provided at the lower part of the insulator 7. A metal shell 8 is provided on the outer side of the insulator 7, and a semi-conductive layer 9 is sprayed on the surface of the insulator 7 located inside the metal shell 8. The semi-conductive layer 9 is in contact with the metal shell 8 and is conductive.

[0026] like Figure 1 As shown, in an embodiment of the present invention, the coil body includes an iron core 1, a secondary winding 2 and a primary winding 3. The secondary winding 2 and the primary winding 3 are concentrically wound on an insulating frame from the inside to the outside and then fitted onto the core post of the iron core 1. The primary lead of the primary winding 3 is connected to the primary high-voltage terminal 5, and the secondary lead of the secondary winding 2 is connected to the secondary terminal.

[0027] Furthermore, the insulator 7 is installed on the base plate 15, which is connected to the EMU, and the primary high-voltage insulating sleeve 4 is connected to the primary connecting cable 16 on the EMU.

[0028] In this embodiment of the invention, the shielding mesh 6 consists of a ring-shaped metal wire mesh with symmetrically arranged embedded nuts. The outer surfaces of the ring-shaped metal wire mesh and the embedded nuts are uniformly coated with a layer of semi-conductive paint. The embedded nuts are embedded within the insulator 7. The semi-conductive layer 9 is semi-conductively connected to the shielding mesh 6, allowing the product to be touched while energized.

[0029] In embodiments of the present invention, the secondary terminals include an input secondary terminal 12 and an output secondary terminal 13, and a secondary fuse 14 is provided on the line connected to the input secondary terminal 12. Through the principle of electromagnetic induction, the input secondary terminal 12 and the output secondary terminal 13 obtain a secondary voltage proportional to the primary voltage.

[0030] Furthermore, the secondary terminal is enclosed by the protruding part of the metal housing 8 and then sealed by the secondary terminal cover plate 11. The protruding part of the metal housing 8 is provided with a waterproof cable connector 10 that connects to the secondary terminal.

[0031] In an embodiment of the present invention, the primary high-voltage insulating bushing 4 and the insulator 7 are integrally formed by epoxy resin casting, and the primary high-voltage insulating bushing 4 has a conical structure. The insulator 7 has a cuboid structure, and transition slopes are provided on the top, left and right sides of the front and rear ends.

[0032] This invention provides a metal-clad high-voltage voltage transformer for high-speed trains, the manufacturing process of which is as follows:

[0033] Secondary winding 2 and primary winding 3 are concentrically wound from the inside out onto an insulating frame and then fitted onto the core post of iron core 1. Secondary winding 2 leads to input secondary terminal 12 and output secondary terminal 13. A secondary fuse 14 is installed on the line of input secondary terminal 12. After insulation and buffer wrapping, it is installed in a fixing fixture. Primary high-voltage terminal 5 passes through shielding mesh 6 and is fixed in a C-shaped head cavity mold, preventing leakage discharge of primary high voltage to the outside. Shielding mesh 6 consists of a ring-shaped metal wire mesh with symmetrically arranged embedded nuts. The outer surfaces of the ring-shaped metal wire mesh and embedded nuts are uniformly sprayed with a layer of semi-conductive paint. Epoxy resin is vacuum cast and, after gel curing, becomes an integral insulator 7. The epoxy resin on the surface of the formed insulator 7 is sandblasted, and then a semi-conductive layer 9 is sprayed onto the surface except for the secondary terminals and primary high-voltage insulating sleeve 4. The end face of the embedded nut is connected to the shielding mesh 6, making operation safer, more reliable, and able to work stably even in harsh environments. After the insulator 7 is treated with a semi-conductive layer 9, it is transferred to the machining workshop to have a metal casing 8 welded on. This connects the metal casing 8 to the semi-conductive layer 9, forming a low-voltage grounding terminal with a surface voltage close to zero, allowing direct contact. The metal casing 8 can withstand significant pressure, protecting the internal structure and the external vehicle body. Even if the transformer fails, it will not affect external equipment. The secondary winding 2 leads out to the input secondary terminal 12 and the output secondary terminal 13. A secondary fuse 14 is installed on the input secondary terminal 12 line. The input secondary terminal 12, the output secondary terminal 13, and the secondary fuse 14 are enclosed by the protruding part of the metal casing 8 and then sealed by the secondary terminal cover plate 11. The secondary cable of the transformer is connected via a waterproof cable connector 10. The semi-finished product with the welded metal casing 8 is fixed to the base plate 15, and the gaps are sealed. This further enhances the dustproof and waterproof capabilities of the input secondary terminal 12 and the output secondary terminal 13. The finished high-voltage insulating sleeve 4 is connected to the primary connecting cable 16 on the EMU. The primary high voltage is equipotentially connected inside the cable, and the product shell and the cable outer shield are equipotentially connected and grounded, making the operation safer, facilitating high-voltage wiring, and saving EMU installation space.

[0034] In this embodiment, the primary high-voltage insulating sleeve 4 encloses the primary high-voltage terminal 5, located either vertically upward on the epoxy resin body or horizontally forward on the primary winding 3. The primary high-voltage insulating sleeve 4 is a standard C-type head with a stepped frustum structure, matching the shape of the primary connecting cable 16, ensuring a tight and reliable seal during insulation. A semi-conductive layer 9 is provided between the inner surface of the metal shell 8 and the outer surface of the epoxy resin. The semi-conductive layer 9 contacts and conducts through the metal shell 8, effectively improving the electric field distribution and reducing the interface field strength. The primary high-voltage terminal 5 passes through the center of the shielding mesh 6, which is connected to two embedded nuts. The end faces of the embedded nuts communicate with the semi-conductive layer 9, working together to make the electric field distribution more uniform, reducing localized excessive field strength, preventing corona discharge, and improving the operational reliability of the electrical equipment. The secondary terminal cover plate 11, in conjunction with the cable waterproof connector 10, leads out the cable and seals the secondary terminal. To prevent short circuits caused by moisture, keep the terminals dry to ensure reliable insulation; prevent damage to wiring from external factors, extending service life; reduce the entry of dust and other contaminants, ensuring good electrical connection. The secondary fuse 14 added to the circuit of input secondary terminal 12 serves the following purposes: 1. Circuit protection: In the event of an overload or short circuit, the fuse melts promptly, cutting off the fault current and protecting secondary equipment from damage. 2. Improved safety: Prevents electrical accidents caused by faults, ensuring the safety of personnel and equipment. 3. Prevention of fault escalation: Promptly disconnects the fault point, preventing the fault's impact from spreading. 4. Facilitated maintenance: When the fuse blows, the fault can be quickly detected and replaced or repaired.

[0035] This invention is a metal-clad high-voltage voltage transformer for high-speed trains. It is a new product designed entirely in accordance with national and international standards and the special requirements of high-speed trains. It adopts a rolled iron core and utilizes the electromagnetic conversion principle to enable the secondary voltage to accurately reflect the changes in the primary voltage. It is used for voltage measurement and relay protection. The product has stable insulation, good sealing performance, wide applicability, and small size. It greatly improves the reliability of power supply. The metal shell and high-voltage shielded cable termination technology allow it to be directly installed in the switchgear of high-speed trains, realizing the integrated and miniaturized development of switchgear.

[0036] The metal-clad high-voltage voltage transformer for high-speed trains provided by this invention is made of epoxy resin and metal shell in one piece. It is small in size, flexible in installation, has a uniform electric field, long maintenance cycle and wide application.

[0037] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, extensions, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A metal-clad high-voltage voltage transformer for high-speed trains, characterized in that, The device includes an insulator (7) and a coil body enclosed within the insulator (7). The top or upper side of the insulator (7) is provided with a primary high-voltage insulating sleeve (4). The primary high-voltage insulating sleeve (4) contains a primary high-voltage terminal and a shielding mesh (6) surrounding the primary high-voltage terminal (5). The lower part of the insulator (7) is provided with a secondary terminal. The outside of the insulator (7) is provided with a metal shell (8). The surface of the insulator (7) located inside the metal shell (8) is coated with a semi-conductive layer (9). The semi-conductive layer (9) is in contact with the metal shell (8) and conducts electricity.

2. The metal-clad high-voltage voltage transformer for high-speed trains according to claim 1, characterized in that, The shielding mesh (6) consists of a ring-shaped metal wire mesh with symmetrically arranged embedded nuts. The outer surfaces of the ring-shaped metal wire mesh and the embedded nuts are uniformly coated with a layer of semi-conductive paint, and the embedded nuts are embedded in the insulator (7).

3. The metal-clad high-voltage voltage transformer for high-speed trains according to claim 1, characterized in that, The secondary terminals include an input secondary terminal (12) and an output secondary terminal (13), and a secondary fuse (14) is provided on the line connected to the input secondary terminal (12).

4. The metal-clad high-voltage voltage transformer for high-speed trains according to claim 1, characterized in that, The secondary terminal is wrapped by the protruding part of the metal shell (8) and then closed by the secondary terminal cover plate (11). The protruding part of the metal shell (8) is provided with a waterproof cable connector (10) connected to the secondary terminal.

5. The metal-clad high-voltage voltage transformer for high-speed trains according to claim 1, characterized in that, The primary high-voltage insulating bushing (4) and the insulator (7) are integrally formed by epoxy resin casting.

6. The metal-clad high-voltage voltage transformer for high-speed trains according to claim 5, characterized in that, The primary high-voltage insulating bushing (4) has a tapered structure.

7. The metal-clad high-voltage voltage transformer for high-speed trains according to claim 5, characterized in that, The insulator (7) has a cuboid structure, and the top and left and right sides of the front and rear are provided with transition slopes.

8. The metal-clad high-voltage voltage transformer for high-speed trains according to claim 1, characterized in that, The coil body includes an iron core (1), a secondary winding (2) and a primary winding (3). The secondary winding (2) and the primary winding (3) are concentrically wound on an insulating frame from the inside to the outside and then fitted onto the core column of the iron core 1. The primary lead of the primary winding (3) is connected to the primary high-voltage terminal (5), and the secondary lead of the secondary winding (2) is connected to the secondary terminal.

9. The metal-clad high-voltage voltage transformer for high-speed trains according to claim 1, characterized in that, The insulator (7) is mounted on the base plate (15), which is connected to the EMU. The primary high-voltage insulating sleeve (4) is connected to the primary connecting cable (16) on the EMU.

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