Reactive compensation system for railway

Abstract

The utility model discloses a reactive compensation system for a railway, which is simple and reasonable in structure and convenient to install and use. The system is suitable for the railway power supply harmonic field, is stable and reliable in performance, employs the reactive compensation unit of a modular structure, is flexible in combination, is convenient to expand, is simple to install, and is convenient to maintain. The reactive power compensation unit is excellent in self-protection performance, and the requirement for the installation environment can be lowered. The capacitor filled with the gas is small in size, the density of the composite environment-friendly gas injected into the capacitor is close to that of atmospheric pressure, and the composite environment-friendly gas does not generate pressure. Operation is safe and reliable. The capacitor is filled with gas, so that dielectric loss of the capacitor is reduced, the capacitor does not heat during operation, and operation reliability is improved. And large-area popularization and application are worthy.

Description

Technical Field

[0001] The utility model relates to the technical field of railway power systems, in particular to a railway reactive power compensation system with good installation stability, compact structure, small footprint and excellent protection performance. Background Art

[0002] Before a newly built electrified railway is officially opened, there is usually a debugging and trial operation phase of at least 3 to 6 months. During this phase, only test trains are in operation, and the power consumption is very small. The line is in an unloaded state most of the time, which generates a large amount of capacitive reactive power. It also takes a long period for some lines to reach the designed transportation capacity after they are officially opened, and there is also the problem of generating a large amount of capacitive reactive power.

[0003] In addition, because high-speed railways use the AT power supply method, the length of power supply lines has increased exponentially. At the same time, a large number of high-voltage cables are used to transmit electric energy, which greatly increases the capacitive reactive power in the power supply system, resulting in a decrease in the power factor of the power supply system and an increase in voltage, which will affect the normal operation of the power supply system and may even cause damage to related electrical equipment.

[0004] In view of this, it is necessary to carry out reactive power compensation and harmonic suppression for the electrified railway power supply system. At present, the main measure for reactive power compensation and harmonic suppression of the electrified railway power supply system is to install reactive power compensation devices on the load (0.4kV) side. The existing reactive power compensation devices mainly include passive filter devices (FC), thyristor switched capacitors (TSC), phase-controlled reactance SVC (TCR+FC), magnetically controlled reactance SVC (MSVC) or static VAR generator (SVG), active power filter (APF), etc.

[0005] However, the reactive power compensation device in the prior art has the disadvantages of low device integration and protection, and cumbersome installation, replacement and maintenance operations. At the same time, capacitors usually use liquid perfusion medium, which has the risk of fire and environmental pollution due to oil leakage. Utility Model Content

[0006] The utility model provides a reactive power compensation system for railways.

[0007] The utility model provides the following solutions:

[0008] A reactive power compensation system for railways, comprising:

[0009] A plurality of reactive power compensation units, wherein the plurality of reactive power compensation units are connected in parallel between the power supply side and the load side of the electrified railway;

[0010] A control unit, the control unit is connected to the upstream of the plurality of reactive power compensation units, and the plurality of reactive power compensation units are respectively connected to the control unit;

[0011] The reactive power compensation unit includes a main case, a base, a low-voltage tuning reactor and a low-voltage self-healing power capacitor; the low-voltage tuning reactor is connected in series with the low-voltage self-healing power capacitor and is arranged inside the main case; the four sides of the base are folded upward to form a receiving groove, the bottom of the main case forms a protrusion adapted to the receiving groove, the rear end of the main case is provided with a card slot, and the rear end folding plate of the base is provided with a claw extending toward the card slot; the base is used to be connected to a fixed object, so that after the base is fixed, the main case is pushed to move from front to back, so that the protrusion enters the receiving groove and the claw enters the card slot.

[0012] Preferably: the front end folding plate of the base is provided with at least two through holes, and the front end of the main chassis is provided with at least two threaded holes; after the protrusion enters the accommodating groove, at least two of the through holes correspond one-to-one with at least two of the threaded holes, so that the main chassis is connected to the base by at least two screws.

[0013] Preferably, two handles are provided on the top of the main box.

[0014] Preferably: a shutter structure is provided on one side of the main chassis, and a notch is provided on the other side of the main chassis, and the notch is used to take out and place the low-voltage tuning reactor and / or the low-voltage self-healing power capacitor.

[0015] Preferably: a main junction box and a weak current junction box are provided at the front end of the main box.

[0016] Preferably, the low-voltage tuning reactor comprises an iron core copper or aluminum winding structure, and the iron core comprises a plurality of stacked cold-rolled silicon steel sheets.

[0017] Preferably: the low-voltage self-healing power capacitor comprises an aluminum shell, a metallized polypropylene film in a wound state, and a filler; the metallized polypropylene film and the filler are both sealed in the aluminum shell.

[0018] Preferably, the filler includes a composite environmentally friendly gas, and the pressure formed by the composite environmentally friendly gas in the aluminum shell is the same as the standard atmospheric pressure.

[0019] According to the specific embodiments provided by the utility model, the utility model discloses the following technical effects:

[0020] Through the utility model, a reactive power compensation system for railways can be realized. In one implementation mode, the system has a simple and reasonable structure and is easy to install and use. The system is suitable for on-site use of railway power supply harmonics, has stable and reliable performance, and adopts a reactive power compensation unit with a modular structure, which is flexible in combination, convenient in expansion, simple in installation, and easy to maintain. The reactive power compensation unit has excellent self-protection performance and can reduce the requirements for the installation environment. The gas-filled capacitor is small in size, and the composite environmentally friendly gas injected into the capacitor has a gas density close to atmospheric pressure and does not generate pressure itself. The operation is safe and reliable. Filling the capacitor with gas reduces the dielectric loss of the capacitor, and the capacitor itself does not generate heat during operation, which improves the reliability of operation. It is worthy of large-scale promotion and use.

[0021] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a structural schematic diagram of a reactive power compensation system for railways provided by an embodiment of the utility model;

[0024] Figure 2 This is a schematic diagram of a reactive power compensation system for railways provided by an embodiment of the utility model;

[0025] Figure 3 This is a schematic diagram of the installation process of the main box and the base provided by the embodiment of the utility model;

[0026] Figure 4 It is a structural schematic diagram of a low-voltage tuning reactor provided by an embodiment of the utility model;

[0027] Figure 5 It is a structural schematic diagram of a low-voltage self-healing power capacitor provided by an embodiment of the utility model.

[0028] In the figure: reactive power compensation unit 1, main box 11, protrusion 111, handle 112, main junction box 113, weak current junction box 114, base 12, accommodating groove 121, claw 122, low-voltage tuning reactor 13, iron core 131, winding 132, low-voltage self-healing power capacitor 14, control unit 2. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the utility model.

[0030] Example

[0031] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , is a railway reactive power compensation system provided by an embodiment of the utility model, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown, the system may include:

[0032] A plurality of reactive power compensation units 1, wherein the reactive power compensation units 1 are connected in parallel and are respectively connected between the power supply side and the load side of the electrified railway;

[0033] A control unit 2, wherein the control unit 2 is connected to the upstream of the plurality of reactive power compensation units 1, and the plurality of reactive power compensation units 1 are respectively connected to the control unit 2;

[0034] The reactive power compensation unit 1 includes a main box 11, a base 12, a low-voltage tuning reactor 13 and a low-voltage self-healing power capacitor 14; the low-voltage tuning reactor 13 and the low-voltage self-healing power capacitor 14 are connected in series and arranged inside the main box 11; the four sides of the base 12 are folded upward to form a receiving groove 121, and the bottom of the main box 11 forms a protrusion 111 adapted to the receiving groove 121, the rear end of the main box 11 is provided with a card slot, and the rear end folding plate of the base 12 is provided with a claw 122 extending toward the card slot; the base 12 is used to be connected to a fixed object, so that after the base 12 is fixed, the main box 11 is pushed to move from front to back, so that the protrusion 111 enters the receiving groove 121 and the claw 122 enters the card slot.

[0035] The reactive power compensation system for railways provided in the embodiment of the present application adopts a method of connecting several reactive power compensation units 1 in parallel, and can be applied to a variety of application scenarios with different compensation requirements. The number of reactive power compensation units 1 can be increased or decreased according to actual needs. The control unit 2 can realize self-monitoring and fault diagnosis functions, monitor the operating status of the equipment in real time, and take protective measures quickly when a fault occurs to ensure the safe and stable operation of the power grid.

[0036] At the same time, the reactive power compensation unit 1 provided in the embodiment of the present application adopts the mode of split arrangement of the main box 11 and the base 12, which is convenient for the installation of the reactor and the capacitor in the main box 11. At the same time, in actual use, the base 12 can be first fixed to the fixed object, and then the main box 11 can be installed. Such a method can greatly improve the convenience of construction. At the same time, when it is necessary to repair and replace the components in the main box 11, it is only necessary to separate the main box 11 from the base 12, and there is no need to separate the base 12 from the fixed object (the base 12 usually needs to be connected to the ground with expansion bolts and other components, and the disassembly and assembly are both troublesome and laborious), which reduces the difficulty of operation and saves operation time. Through the design of the split structure of the base 12 and the main box 11, it is also conducive to the adjustment of the capacitor level. In actual use, it is only necessary to ensure the horizontality of the base 12 installation. Since the base 12 is light in weight and easy to move and operate, the difficulty of operation of only adjusting the horizontality of the base 12 will be greatly reduced relative to the adjustment level of the whole machine. Maintaining the horizontality of the base 12 can ensure that the capacitor is kept as horizontal as possible, which is conducive to the capacitor to play the best effect.

[0037] In addition, the embodiment of the present application uses the main box 11 as a protective device, which can protect the low-voltage tuning reactor 13 and the low-voltage self-healing power capacitor 14 located inside it, greatly reducing the safety protection requirements for the installation scene. It is particularly suitable for use along the railway.

[0038] It is understandable that the control unit provided in the embodiment of the present application can be composed of control modules commonly used in the prior art. The control unit mainly performs sampling and controls the size of the compensation reactance value. In specific implementation, the control unit can perform instantaneous value sampling on the current transformer and voltage transformer on the secondary side of the power supply transformer to obtain the instantaneous value of current sampling and the instantaneous value of voltage sampling of at least one power frequency cycle; determine whether the data obtained by instantaneous value sampling is valid; if valid, calculate the reactive power of the power supply arm based on the instantaneous value of current sampling and the instantaneous value of voltage sampling of at least one power frequency cycle; calculate the reactance value required to compensate for the reactive power; and adjust the reactance parameters of the capacitive reactive compensation device to the calculated reactance value.

[0039] The rear end of the main chassis 11 provided in the embodiment of the present application can be connected to the base 12 through a card slot and a claw 122. In order to further improve the stability after the connection, the embodiment of the present application can also provide that the front end folding plate of the base 12 is provided with at least two through holes, and the front end of the main chassis 11 is provided with at least two threaded holes; after the protrusion 111 enters the accommodating groove 121, at least two of the through holes correspond to at least two of the threaded holes one by one, so that the main chassis 11 and the base 12 are connected by at least two screws. The corresponding through holes and threaded holes can connect the main chassis 11 and the base 12 by using matching screws, which can achieve the purpose of stable connection and facilitate disassembly.

[0040] In order to facilitate moving the main box 11 , the embodiment of the present application may further provide two handles 112 on the top of the main box 11 .

[0041] In order to ensure that the main box 11 provided in the embodiment of the present application has excellent heat dissipation performance while ensuring a certain degree of protection, the embodiment of the present application can provide that one side of the main box 11 is provided with a shutter structure, and the other side of the main box 11 is provided with a notch, and the notch is used to take and place the low-voltage tuning inductor 13 and / or the low-voltage self-healing power capacitor 14.

[0042] In order to facilitate wiring, the embodiment of the present application can also provide that the front end of the main box 11 is provided with a main wiring box 113 and a weak current wiring box 114. Both the main wiring box 113 and the weak current wiring box 114 can adopt a flip-up opening structure and be waterproofed, which is not only conducive to wiring operation, but also can achieve a good waterproof effect. The main wiring box 113 and the weak current wiring box 114 are arranged on the same side, which is conducive to on-site wiring and ensures neatness after wiring.

[0043] It can be understood that the main functional components of the reactive power compensation unit 1 provided in the embodiment of the present application adopt a low-voltage tuned reactor 13 and a low-voltage self-healing power capacitor 14 connected in series. The low-voltage tuned reactor 13 can be used to suppress harmonic amplification and protect other electrical equipment. In specific implementation, the embodiment of the present application can provide that the low-voltage tuned reactor 13 includes an iron core 131 type copper or aluminum winding 132 structure, and the iron core 131 includes a plurality of stacked cold-rolled silicon steel sheets. The low-voltage tuned reactor 13 is used to improve the quality of electric energy, improve the power factor of the distribution system, reduce the interference of harmonics on capacitors, prevent harmonic amplification, and reduce harmonic pollution.

[0044] In practical applications, the iron core 131 is made of high-quality cold-rolled silicon steel sheets, which are punched and sheared by a high-speed punching machine, with small burrs, regular and uniform, neat and beautiful laminations, ensuring the performance of low temperature rise and low noise of the reactor. The coil is made of high-quality insulated wires, which are wound by special machines and have the advantages of good flatness and beautiful appearance. The low-voltage tuned reactor is a special reactor specially used to suppress harmonic amplification and protect other electrical equipment. The low-voltage tuned reactor 13 is an iron core copper or aluminum winding 132 structure, which is cast with polyester resin under vacuum, with a casting environment temperature of 40°C and a drying temperature of 155°C.

[0045] Furthermore, the embodiment of the present application can also provide that the low-voltage self-healing power capacitor 14 includes an aluminum shell, a metallized polypropylene film in a wound state, and a filler; the metallized polypropylene film and the filler are sealed in the aluminum shell. In a specific implementation, the filler includes a composite environmentally friendly gas, and the pressure formed by the composite environmentally friendly gas in the aluminum shell is the same as the standard atmospheric pressure.

[0046] The low-voltage self-healing power capacitor is made of metalized polypropylene film, which is cut and wound in a clean environment below dynamic level 1000, and then sealed in an aluminum shell by gold spraying on the cross section. Through advanced production technology, the aluminum shell is dried under high vacuum and special protective materials are injected, and the unique and reliable safe overpressure breaking and protection technology is used to make it the latest generation of low-voltage self-healing power capacitor.

[0047] Cylindrical design, small size. Through new technology and process, the capacitor is small in size, light in weight and low in height, which meets people's requirements for three-dimensional space and brings greater economic benefits to users.

[0048] The capacitor is filled with special protective gas instead of liquid, epoxy resin, paraffin and other filling media, so there will be no fire risk caused by oil filling or oil leakage, avoiding damage and pollution to the ecological environment. The gas is used as the internal medium of the capacitor to achieve a true dry effect, and the over-voltage pull-off protection device ensures that the capacitor is explosion-proof. Through new technologies and processes, the capacitor is small in size, light in weight, and low in height, which meets people's requirements for three-dimensional space and brings greater economic benefits to users.

[0049] The low-voltage self-healing power capacitor provided in the embodiment of the present application has a cylindrical metal shell, a fully sealed structure, a small size, a light weight, excellent electrical properties, and a small power factor loss. It has excellent self-healing performance and can self-repair and work normally after a local breakdown of the dielectric caused by overvoltage. The fully dry structure, the low-voltage self-healing power capacitor core group is heat-formed by high-vacuum silicon impregnation, and then filled with flame-retardant colloid material to avoid oil pollution to the environment. The low-voltage self-healing power capacitor has a built-in discharge resistor, and the residual voltage is less than 75V after the capacitor cuts off the power supply for 3 minutes. The low-voltage self-healing power capacitor has a built-in overvoltage protection device, which can automatically cut off the power supply in the event of a fault or overload.

[0050] In summary, the reactive power compensation system for railways provided by the present application has a simple and reasonable structure and is easy to install and use. The system is suitable for on-site use of harmonics in railway power supply arms, has stable and reliable performance, and adopts a reactive power compensation unit with a modular structure, which is flexible in combination, convenient in expansion, simple in installation, and easy to maintain. The reactive power compensation unit itself has excellent protection performance and can reduce the requirements for the installation environment. The gas-filled capacitor is small in size, and the composite environmentally friendly gas injected into the capacitor has a gas density close to atmospheric pressure and does not generate pressure itself. The operation is safe and reliable. Filling the capacitor with gas reduces the dielectric loss of the capacitor, and the capacitor itself does not generate heat during operation, which improves the reliability of operation. It is worthy of large-scale promotion and use.

[0051] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A reactive power compensation system for railways, characterized in that: include: A plurality of reactive power compensation units, wherein the plurality of reactive power compensation units are connected in parallel between the power supply side and the load side of the electrified railway; A control unit, the control unit is connected to the upstream of the plurality of reactive power compensation units, and the plurality of reactive power compensation units are respectively connected to the control unit; The reactive power compensation unit comprises a main box, a base, a low-voltage tuning reactor and a low-voltage self-healing power capacitor; The low-voltage tuning reactor is connected in series with the low-voltage self-healing power capacitor and is arranged inside the main chassis; the four sides of the base are folded upward to form a receiving groove, and the bottom of the main chassis forms a protrusion adapted to the receiving groove, the rear end of the main chassis is provided with a card slot, and the rear end folding plate of the base is provided with a claw extending toward the card slot; the base is used to be connected to a fixed object, so that after the base is fixed, the main chassis is pushed to move from front to back, so that the protrusion enters the receiving groove and the claw enters the card slot.

2. The railway reactive power compensation system according to claim 1, characterized in that: The front end folding plate of the base is provided with at least two through holes, and the front end of the main chassis is provided with at least two threaded holes; after the protrusion enters the accommodating groove, at least two of the through holes correspond one-to-one with at least two of the threaded holes, so that the main chassis and the base can be connected by at least two screws.

3. The railway reactive power compensation system according to claim 1, characterized in that: Two handles are arranged on the top of the main box.

4. The railway reactive power compensation system according to claim 1, characterized in that: A shutter structure is arranged on one side of the main box, and a notch is arranged on the other side of the main box, and the notch is used for taking and placing the low-voltage tuning reactor and / or the low-voltage self-healing power capacitor.

5. The railway reactive power compensation system according to claim 1, characterized in that: The front end of the main box is provided with a main junction box and a weak current junction box.

6. The railway reactive power compensation system according to claim 1, characterized in that: The low-voltage tuning reactor comprises an iron core type copper or aluminum winding structure, and the iron core comprises a plurality of stacked cold-rolled silicon steel sheets.

7. The railway reactive power compensation system according to claim 1, characterized in that: The low-voltage self-healing power capacitor comprises an aluminum shell, a metallized polypropylene film in a wound state, and a filler; the metallized polypropylene film and the filler are both sealed in the aluminum shell.

8. The railway reactive power compensation system according to claim 7, characterized in that: The filler includes a composite environmentally friendly gas, and the pressure formed by the composite environmentally friendly gas in the aluminum shell is the same as the standard atmospheric pressure.

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