Dynamic active filtering system for railway

Abstract

The utility model discloses a dynamic active filtering system for a railway, which can remarkably improve the electric energy quality of a power grid, reduce the damage of harmonic waves to power grid equipment, prolong the service life of the equipment and improve the stability and reliability of a power system. Gas entering the dynamic active filter can be pre-cooled, smooth circulation of the gas is guaranteed through two stages of cooling fans, and the cooling effect of the cabinet body is improved. And two-stage dust removal and filtration are adopted, so that the dustproof performance of the cabinet body is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of railway power supply, in particular to a dynamic active filtering system for railways. Background Art

[0002] The power distribution system of each railway station is particularly important, including dispatching, lighting, warning, elevators, gates, etc. Due to the use of many modern precision power equipment, certain harmonics and reactive power will inevitably be injected into the power grid, which will seriously affect the power quality of the low-voltage distribution network, causing the waveforms of voltage and current in the power grid to be distorted, which will accelerate the aging of cables and increase losses. At the same time, the harmonics injected into the power grid can easily destroy sensitive precision electrical equipment.

[0003] To address this problem, the use of a three-phase active filter for harmonic and reactive power control is currently the most effective solution. It can perform real-time and dynamic current tracking and compensation as the load current changes. The compensation current is equal in magnitude and opposite in direction to the harmonic and reactive current in the load. In this way, after vector addition and cancellation on the grid side, the final grid output current is only the active current consumed by the load.

[0004] Active filtering is a filter composed of RC elements and operational amplifiers, also known as RC active filters. Its function is to allow signals within a certain frequency range to pass through, and to suppress or sharply attenuate signals outside this frequency range. It can be used in information processing, data transmission, interference suppression, etc., but due to the frequency band limitation of operational amplifiers, this type of filter is mainly used in the low-frequency range.

[0005] Active filter modules and other electronic devices are usually installed in active filter cabinets. Since active filter modules generate a lot of heat during operation, it is necessary to quickly discharge this heat from the active filter cabinet. When active filter systems are applied to railway systems, higher requirements are placed on the heat dissipation and dust prevention effects of active filter cabinets. The existing active filter cabinets have poor heat dissipation effects. One of the reasons is that the active filter cabinets and active filter modules usually use fans to drive air circulation for heat dissipation. Since the air inhaled by the active filter module is at room temperature, the heat dissipation effect of the active filter module is not good in some occasions with high room temperature. At the same time, since the active filter cabinet needs to be provided with an air inlet, a layer of filter is usually provided at the air inlet for dust prevention. Since the air that has passed through a layer of filtration will be directly sucked into the interior of the active filter module, the impurities remaining in the air can easily enter the interior of the active filter module, and the dust prevention effect is not good. Utility Model Content

[0006] The utility model provides a dynamic active filtering system for railways.

[0007] The utility model provides the following solutions:

[0008] A dynamic active filtering system for railways, comprising:

[0009] A plurality of active dynamic filters, each of which is used to be connected between the power supply side and the load side of the power supply arm of the electrified railway, so as to detect and compensate for harmonic current in the power grid in real time and dynamically adjust reactive power;

[0010] A cabinet, wherein a longitudinal partition is provided inside the cabinet, and the longitudinal partition is used to separate the interior of the cabinet into a first chamber and a second chamber that are independent of each other; the first chamber is provided with a plurality of transverse partitions, and one end of each of the plurality of transverse partitions is connected to the longitudinal partition; an accommodation space for accommodating a set of the active dynamic filter is formed between two adjacent transverse partitions;

[0011] The back plate at the rear end of the cabinet is provided with a plurality of first air inlets, and the first air inlets are provided with a first filter assembly; at least one second air inlet is respectively provided on the longitudinal partition at a position relative to each of the accommodating spaces, and the second air inlet is provided with a second filter assembly; a plurality of thermoelectric cooling units are provided on the back plate, and the plurality of thermoelectric cooling units are used to reduce the temperature of the gas in the second chamber;

[0012] The active dynamic filter comprises a housing, a first cooling fan is arranged at the front end of the housing, a third air inlet is arranged at the rear end of the housing, and after the active dynamic filter is placed in the accommodating space, the third air inlet is opposite to the corresponding second air inlet;

[0013] The front door panel of the cabinet is provided with a second cooling fan, and the second cooling fan is used to discharge the gas inside the cabinet.

[0014] Preferably, the thermoelectric refrigeration unit includes a ceramic flat-plate type primary semiconductor refrigeration component.

[0015] Preferably: a handle is provided at the front end of the housing.

[0016] Preferably: a fixed wing plate is provided at the front end of the shell, and the fixed wing plate is used to connect the shell with the cabinet.

[0017] Preferably, the dynamic active filter comprises a sensor and a signal processing unit for monitoring the current waveform in the power grid so as to identify fundamental and harmonic components in the power grid.

[0018] Preferably, the dynamic active filter further comprises an inverter, wherein the inverter is used to generate a compensation current whose magnitude and phase are opposite to the grid harmonic current according to the detected harmonic information.

[0019] Preferably, the dynamic active filter further comprises a power switch, and the power switch is used to implement switching according to a target control strategy to generate a required compensation current.

[0020] According to the specific embodiments provided by the utility model, the utility model discloses the following technical effects:

[0021] The utility model can realize a dynamic active filtering system for railways. In one implementation mode, the system can significantly improve the power quality of the power grid, reduce the harm of harmonics to power grid equipment, extend the service life of equipment, and improve the stability and reliability of the power system. The gas entering the dynamic active filter can be pre-cooled, and the two-stage cooling fan can ensure smooth gas circulation, thereby improving the heat dissipation effect of the cabinet. The two-stage dust removal and filtration are adopted to greatly improve the dustproof performance of the cabinet.

[0022] 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

[0023] 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.

[0024] Figure 1 It is a structural schematic diagram of a dynamic active filtering system for railways provided by an embodiment of the utility model;

[0025] Figure 2 It is a front view of the active dynamic filter provided by an embodiment of the utility model;

[0026] Figure 3 It is a side view of the active dynamic filter provided by an embodiment of the utility model;

[0027] Figure 4 It is a wiring diagram of an active dynamic filter provided by an embodiment of the utility model;

[0028] Figure 5 It is a principle diagram of an active dynamic filter provided in an embodiment of the utility model.

[0029] In the figure: an active dynamic filter 1, a housing 11, a first cooling fan 12, a handle 13, a cabinet 2, a longitudinal partition 21, a transverse partition 22, a first filter assembly 23, a second filter assembly 24, a thermoelectric cooling unit 25, and a second cooling fan 26. DETAILED DESCRIPTION

[0030] 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.

[0031] Example

[0032] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , is a railway dynamic active filtering 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:

[0033] A plurality of active dynamic filters 1, each of which is used to be connected between the power supply side and the load side of the power supply arm of the electrified railway, so as to detect and compensate for harmonic currents in the power grid in real time and dynamically adjust reactive power;

[0034] A cabinet 2, wherein a longitudinal partition 21 is provided inside the cabinet 2, and the longitudinal partition 21 is used to separate the interior of the cabinet 2 into a first chamber and a second chamber that are independent of each other; the first chamber is provided with a plurality of transverse partitions 22, and one end of each of the plurality of transverse partitions 22 is connected to the longitudinal partition 21; an accommodation space for accommodating a set of the active dynamic filter 1 is formed between two adjacent transverse partitions 22;

[0035] The back plate at the rear end of the cabinet 2 is provided with a plurality of first air inlets, and the first air inlets are provided with a first filter assembly 23; at least one second air inlet is provided on the longitudinal partition plate 21 at a position relative to each of the accommodating spaces, and the second air inlet is provided with a second filter assembly 24; a plurality of thermoelectric cooling units 25 are provided on the back plate, and the plurality of thermoelectric cooling units 25 are used to reduce the temperature of the gas in the second chamber;

[0036] The active dynamic filter 1 comprises a housing 11, a first cooling fan 12 is disposed at the front end of the housing 11, a third air inlet is disposed at the rear end of the housing, and after the active dynamic filter 1 is placed in the accommodation space, the third air inlet is opposite to the corresponding second air inlet;

[0037] A second cooling fan 26 is disposed on the front door panel of the cabinet 2 , and the second cooling fan 26 is used to discharge the gas inside the cabinet 2 .

[0038] The dynamic active filtering system for railways provided in the embodiment of the present application can be provided with multiple sets of active dynamic filters in a cabinet for use under different voltage levels. The cabinet adopts a multi-chamber design, the first chamber is used to set the active dynamic filter, and the second chamber forms an independent space. The gas required for cooling enters the second chamber through the back plate at the rear end of the cabinet, and is filtered once through the first filter assembly at the first air inlet. At the same time, the second chamber can maintain a relatively low temperature environment through the provided thermoelectric refrigeration unit. The second cooling fan of the active dynamic filter will introduce the gas in the second chamber into the interior of the shell through the second air inlet and the third air inlet for cooling. Before the gas enters the shell, it will be filtered twice through the second filter assembly, which can achieve a good dust removal effect. Finally, the high-temperature gas in the cabinet will be guided by the first cooling fan to be discharged to the outside of the cabinet.

[0039] It can be understood that the refrigeration unit provided in the embodiment of the present application adopts a thermoelectric refrigeration unit. The reason is mainly due to the simple structure and strong weather resistance of the thermoelectric refrigeration unit. Compared with the traditional air-conditioning refrigeration method, it has the advantages of low overall cost and small internal space of the cabinet. It is especially suitable for use along the railway.

[0040] Furthermore, the embodiment of the present application may also provide that the thermoelectric refrigeration unit 25 includes a ceramic flat-plate type primary semiconductor refrigeration component.

[0041] In order to further facilitate the installation of the active dynamic filter, the embodiment of the present application may also provide a handle 13 at the front end of the housing 11. A fixed wing plate is provided at the front end of the housing, and the fixed wing plate is used to connect the housing to the cabinet.

[0042] Furthermore, the embodiment of the present application may also provide that the dynamic active filter includes a sensor and a signal processing unit, which are used to monitor the current waveform in the power grid so as to identify the fundamental wave and harmonic wave components in the power grid.

[0043] The dynamic active filter further includes an inverter, which is used to generate a compensation current with a magnitude and a phase opposite to the grid harmonic current according to the detected harmonic information.

[0044] The dynamic active filter further includes a power switch, which is used to implement switching according to a target control strategy to generate a required compensation current.

[0045] Dynamic active filtering is a power quality control device based on power electronics technology. It can detect and compensate for harmonic currents in the power grid in real time, and dynamically adjust reactive power, thereby significantly improving the power quality of the power grid. Its working principle mainly includes the following steps:

[0046] 1. Monitoring and identification, the dynamic active filter is equipped with advanced sensors and signal processing units to monitor the current waveform in the power grid in real time. Through algorithms such as Fourier transform (FFT), the filter can accurately identify the fundamental and harmonic components in the power grid, as well as their amplitude and phase angle.

[0047] 2. The inverter generates a compensation current. Once the harmonic current is identified, the inverter part of the dynamic active filter generates a compensation current with a magnitude and phase opposite to the grid harmonic current based on the detected harmonic information. This compensation current is injected into the grid through the power switch connected to the grid.

[0048] 3. Power switch control, the IGBT or other types of power switches inside the dynamic active filter are switched quickly according to a specific control strategy to generate the required compensation current. The control strategy is usually based on PWM (pulse width modulation) technology to ensure the accuracy and efficiency of the compensation current.

[0049] 4. Dynamic adjustment: Dynamic active filters can not only eliminate static harmonics, but also respond to dynamic changes in grid load and adjust compensation strategies in real time. For example, when the load suddenly increases, the filter can quickly increase the compensation current to maintain the stability of the grid voltage.

[0050] 5. Grid interaction, through interaction with the grid, the dynamic active filter can automatically adapt to changes in grid conditions, such as fluctuations in frequency and voltage. It can work independently or in conjunction with other power quality control equipment.

[0051] 6. Intelligent control, modern dynamic active filters are usually equipped with an intelligent control system that can achieve self-learning and optimization of control strategies. Through historical data analysis and machine learning algorithms, the filter can predict grid load changes, adjust compensation strategies in advance, and improve compensation efficiency.

[0052] In summary, the dynamic active filtering system for railways provided by this application can significantly improve the power quality of the power grid, reduce the harm of harmonics to power grid equipment, extend the service life of equipment, and improve the stability and reliability of the power system. The gas entering the dynamic active filter can be pre-cooled, and the two-stage cooling fan can ensure smooth gas circulation, thereby improving the heat dissipation effect of the cabinet. The two-stage dust removal and filtration greatly improves the dustproof performance of the cabinet.

[0053] 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.

[0054] 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 dynamic active filtering system for railways, characterized in that: include: A plurality of active dynamic filters, each of which is used to be connected between the power supply side and the load side of the power supply arm of the electrified railway, so as to detect and compensate for harmonic current in the power grid in real time and dynamically adjust reactive power; A cabinet, wherein a longitudinal partition is provided inside the cabinet, and the longitudinal partition is used to separate the interior of the cabinet into a first chamber and a second chamber that are independent of each other; the first chamber is provided with a plurality of transverse partitions, and one end of each of the plurality of transverse partitions is connected to the longitudinal partition; an accommodation space for accommodating a set of the active dynamic filter is formed between two adjacent transverse partitions; The back plate at the rear end of the cabinet is provided with a plurality of first air inlets, and the first air inlets are provided with a first filter assembly; at least one second air inlet is respectively provided on the longitudinal partition at a position relative to each of the accommodating spaces, and the second air inlet is provided with a second filter assembly; a plurality of thermoelectric cooling units are provided on the back plate, and the plurality of thermoelectric cooling units are used to reduce the temperature of the gas in the second chamber; The active dynamic filter comprises a housing, a first cooling fan is arranged at the front end of the housing, a third air inlet is arranged at the rear end of the housing, and after the active dynamic filter is placed in the accommodating space, the third air inlet is opposite to the corresponding second air inlet; The front door panel of the cabinet is provided with a second cooling fan, and the second cooling fan is used to discharge the gas inside the cabinet.

2. The railway dynamic active filtering system according to claim 1, characterized in that: The thermoelectric refrigeration unit includes a ceramic flat plate type primary semiconductor refrigeration component.

3. The railway dynamic active filtering system according to claim 1, characterized in that: A handle is arranged at the front end of the shell.

4. The railway dynamic active filtering system according to claim 1, characterized in that: A fixed wing plate is arranged at the front end of the shell, and the fixed wing plate is used to connect the shell with the cabinet.

5. The railway dynamic active filtering system according to claim 1, characterized in that: The dynamic active filter comprises a sensor and a signal processing unit for monitoring the current waveform in the power grid so as to identify fundamental wave and harmonic wave components in the power grid.

6. The railway dynamic active filtering system according to claim 5, characterized in that: The dynamic active filter further includes an inverter, which is used to generate a compensation current with a magnitude and a phase opposite to the grid harmonic current according to the detected harmonic information.

7. The railway dynamic active filtering system according to claim 6, characterized in that: The dynamic active filter further includes a power switch, which is used to implement switching according to a target control strategy to generate a required compensation current.

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