Background
The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.
The ice coating of the ground station line of the rail transit is one of serious threats of frequent power supply of the rail transit; when the ice coating accident occurs in the rail transit, the line fault occurs when the rail transit is light, so that the rail transit cannot operate, and the broken line and the inverted rod are caused when the rail transit is heavy, so that the large-area paralysis of the line is even caused. Because of the complicated south-north topography and the large climate difference, the line icing accident often happens, which brings a certain influence to the rail traffic and even brings inconvenience to the normal daily travel of people, thereby causing a certain economic loss.
For the lines in cold areas, the ice and snow freezing disasters in winter have great influence on a track traffic contact net system and even damage to a contact net; the icing can lead to the overhead line system overload, and the actual icing of circuit exceeds the biggest icing thickness of design, and circuit icing weight increases, and the wind pressure area increases after the icing, leads to accidents such as rail transit traction power supply line clue breaking, gold utensil damage, insulator chain upset, pillar collapse. The uneven ice coating of the track traffic traction power supply line contact net can cause self-oscillation and wind-dancing of the contact net in a wind-driven state, so that serious accidents such as phase-to-ground flashover, metal damage, pole falling, wire breakage, tripping, power failure and the like are caused. Meanwhile, if the contact line is swung beyond the working range of the pantograph, the bow net accidents such as disengaging and scraping can occur. Once the damage occurs, the contact net equipment can be damaged to cause power failure accidents, so that the train can not run and railway transportation is interrupted.
In order to prevent and treat ice and snow freezing disasters, the overhead contact system needs to be designed with anti-ice and snow freezing protection at the design stage, the load of the overhead line system support column during ice and snow covering is considered in calculation, so that the support column is prevented from overturning during ice and snow covering; vibration-proof whips are arranged on the additional leads, so that the occurrence of broken line accidents caused by the waving of the leads is avoided; in the areas with serious ice and snow, an alternating current ice melting device or a mobile direct current ice melting device is arranged in a power substation.
The inventor knows that the current contact network ice melting technology is still in a research stage, and most of the ice melting methods of the power transmission lines are used, so that a perfect and efficient ice melting method is lacked. The deicing method of the existing transmission overhead line mainly comprises the following steps:
(1) Mechanical deicing
The simple manual deicing is adopted, but a large amount of labor force is needed, the safety is poor, the consumed time is long, the efficiency is low, secondary icing is easy, and the deicing device is only suitable for deicing of the wire with good working environment and short-distance icing.
(2) Contact net hot-sliding deicing device
The locomotive slowly passes through the ice coating area, but when the pantograph passes through the ice coating, the pantograph or the contact line is easily damaged, so that the locomotive cannot take current normally.
(3) Chemical agent method
The hydrophobic material is coated on the surface of the wire, so that the adhesion coefficient between the ice coating and the wire is reduced to prevent ice formation; however, the heat generated by friction between the pantograph and the contact line causes the chemical agent to fall off, and the long-term anti-icing effect cannot be maintained.
(4) Thermal ice melting
The current ice melting is particularly dominant, the transmission current higher than normal power transmission is connected on the line, and the ice melting is carried out by utilizing the heat generated by the current, namely the ice melting is carried out by converting electric energy into heat energy, and the ice melting comprises alternating current ice melting and direct current ice melting; the basic principle of alternating current ice melting is that according to the calculated wire ice melting current, a power grid wiring mode is combined, a single line is short-circuited in the middle or at the tail end or a capacitor is connected in series to a corresponding line to compensate line inductance, and the short-circuit current on a contact line is controlled to be in a range allowing passage, so that ice coating is melted and falls off; the basic principle of direct current ice melting is to take an ice-covered wire as a load, switch on direct current at two ends of the load, and melt the ice-covered wire by utilizing the heating of wire resistance. However, the conventional thermal ice melting cannot ensure the normal operation of rail transit in the ice melting process. Therefore, designing a simple and reliable normal operation track traffic overhead line system ice melting system for track traffic and ice melting control of the system is a technical problem to be solved urgently.
Disclosure of Invention
In order to solve the problems, the invention provides the overhead line ice melting system for the rail transit and the control method thereof, which take the characteristics of the rail transit traction power supply and the rail transit electrified operation into consideration, utilize the self voltage of the overhead line, increase the current of the line of the ice melting section by throwing the ice melting device into the ice melting section line under the condition of not changing the load, remove ice coating on the line in a self-heating mode when the line runs under a heavy load or a full load state, and realize uninterrupted ice melting of the overhead line without influencing the normal operation of the rail transit in the whole ice melting process.
According to some embodiments, the first scheme of the invention provides a catenary ice melting system for rail transit, which adopts the following technical scheme:
The overhead line system ice melting system for the rail transit is arranged in a traction power supply system of the rail transit, and at least comprises a traction substation and a subarea, wherein a plurality of ice melting devices which are consistent in structure and connected in parallel on a contact network are adopted, the ice melting devices are all arranged in the subarea, and two ends of each ice melting device are respectively connected in parallel on the contact network; when the rail transit contact net does not need to melt ice, the ice melting device is used as a reactive compensation device to perform reactive compensation on the contact net line, and the electric energy quality of the rail transit contact net is improved.
As a further technical limitation, the overhead line ice melting system for rail transit further comprises an ice melting monitoring device and a controller, wherein the ice melting monitoring device is arranged in the traction substation and is used for monitoring ice coating data and environment data of an overhead line in real time, the controller calculates current required by the ice melting device for ice melting according to the received real-time monitoring data of the ice melting monitoring device and then sends out a control signal to the ice melting device, and the ice melting device receives the control signal and then generates capacitive reactive current to complete the ice melting process.
Further, the ice coating data at least comprises ice melting line terminal voltage, ice melting line current, ice melting line power, ice melting line temperature and operation state of the ice melting device.
As a further technical limitation, a plurality of transformers are arranged in the traction substation, primary sides of the transformers are connected with three-phase alternating current in the traction substation, and secondary sides of the transformers are connected with a contact net and a steel rail in a traction power supply system.
Further, the number of the transformers is matched with that of the ice melting devices.
Furthermore, when the rail transit overhead line system needs to melt ice, the capacitive reactive power is generated based on the ice melting operation in the line needing to melt ice, the capacitive reactive current is injected, the injected capacitive reactive current forms a current loop in the line needing to melt ice, the ice melting device, the secondary side of the transformer and the steel rail, and the ice is melted through heat energy generated by the current.
It should be noted that in the process of ice melting, an ice melting current loop is generated in a line interval where ice melting is required, and lines outside the ice melting line interval are not affected, so that online ice melting without power failure is realized.
As a further technical limitation, the ice melting device adopts a static var generator SVG, a magnetic control dynamic reactive power compensation device MCR or a phase control dynamic reactive power compensation device TCR.
As a further technical limitation, two ends of the ice melting device are respectively connected with the contact net through a first relay and a second relay.
According to some embodiments, a second aspect of the present invention provides a control method for a catenary ice melting system for rail transit, which adopts the catenary ice melting system for rail transit provided by the first aspect, and adopts the following technical scheme:
a control method of a catenary ice melting system for rail transit, comprising:
acquiring real-time icing data of a contact net line;
and controlling the working state of the ice melting device according to the acquired real-time icing data to finish ice melting of the overhead line system.
As a further technical limitation, when ice melting is needed, the controller calculates current required by the ice melting device for ice melting according to the received real-time monitoring data of the ice melting monitoring device, and then sends a control signal to the ice melting device, and the ice melting device generates capacitive reactive current after receiving the control signal, so as to perform ice melting operation of the overhead line system; when the deicing is not needed, the deicing device is used as a reactive compensation device to perform reactive compensation on the contact network line.
Compared with the prior art, the invention has the beneficial effects that:
According to the invention, the characteristics of the rail transit traction power supply and the rail transit electrified operation are considered, the self-voltage of the overhead contact system is utilized, and under the condition that the load size is not changed, the current of the line in the ice melting section is increased by throwing the ice melting device into the ice melting section line, the ice coating on the wire is removed in a self-heating mode when the wire runs under a heavy load or a full load state, the normal operation of the rail transit is not influenced in the whole ice melting process, and the uninterrupted ice melting of the overhead contact system is realized.
Based on the overhead line ice melting system for the rail transit, when ice melting is not needed, the ice melting device can be used as a reactive compensation device to perform reactive compensation on a contact network line, so that the electric energy quality of the overhead line of the rail transit is improved; when the icing data reach the threshold value, the ice melting device is switched to an ice melting working condition, an ice melting current loop is formed through an ice melting circuit, and ice melting operation is carried out on the contact network.
Detailed Description
The invention will be further described with reference to the drawings and examples.
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present invention. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.
In the present invention, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", etc. refer to an orientation or a positional relationship based on that shown in the drawings, and are merely relational terms, which are used for convenience in describing structural relationships of various components or elements of the present invention, and do not denote any one of the components or elements of the present invention, and are not to be construed as limiting the present invention.
In the present invention, terms such as "fixedly attached," "connected," "coupled," and the like are to be construed broadly and refer to either a fixed connection or an integral or removable connection; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the terms in the present invention can be determined according to circumstances by those skilled in the art or relevant scientific research and is not to be construed as limiting the invention.
Embodiments of the invention and features of the embodiments may be combined with each other without conflict.
Example 1
The embodiment of the invention introduces a catenary ice melting system for rail transit.
The embodiment introduces a catenary ice melting system for rail transit, which adopts alternating current ice melting, and installs an ice melting device on a subarea on the basis of an original traction power supply system, wherein the ice melting device can adopt SVG, MCR or TCR, and is connected with the catenary in parallel, so that the ice melting device generates capacitive power, an ice melting line generates alternating current capacitive current to increase the current of the line to be melted, the self heating of the power transmission line is increased, the ice melting of the ice coating line is realized, the power of the ice melting device is controlled, the catenary ice melting process is completed in the normal running process of the rail transit, and the normal running of the rail transit is not influenced in the whole ice melting process.
The present embodiment will be described in detail with reference to an electrified railway as an example.
In the embodiment, the electrified railway traction network adopts power frequency single-phase alternating current, and the rated voltage is 27.5kV. The traction motor is supplied after the step-down of the step-down transformer and the conversion of the converter of the electric locomotive, and the adopted traction power supply system is shown in figure 1, and is specifically as follows:
(1) Traction substation 3
The traction substation 3 is used for converting a three-phase power supply provided by a public network into 27.5kV single-phase power for an electrified railway through the regional substation or the power station 1 and the high-voltage power transmission line 2, and then respectively transmitting the 27.5kV single-phase power to power supply arms on two sides through the power supply line 4 to provide electric energy for the electric locomotive 9.
(2) Traction net
The traction network mainly comprises the contact network 5, and because the contact network 5 is built along a railway, and more branches are near a station, the traction network has a complex structure, is exposed outdoors and is more affected by environmental factors, and the probability of occurrence of faults is higher. The safety of the contact line 5 is thus a reliable operation of the traction power supply system.
(3) Partition 8
The two power supply arms arranged between the two subareas 8 are provided with the subareas to play a role in isolating the electric phase, and the subareas can enable the uplink power supply arm and the downlink power supply arm in the same direction of the compound line section to run in parallel to improve the voltage of the tail ends of the power supply arms; when the phase-induced substation or the power supply arm fails, the power cannot be supplied to the tail end of the contact net 5, and the power can be supplied to the failed power supply arm through the adjacent traction substation 3 in a short time through switching operation in the subarea.
The traction power supply system in this embodiment is further provided with a return line 7 for connecting the feeder 4 and the rail 6.
The overhead line ice melting system for rail transit in this embodiment is shown in fig. 2, where a transformer T1, a transformer T2, and a transformer T3 are installed in a traction substation, primary sides are respectively connected to BC, AB, and CA ends of three-phase alternating current, secondary sides are connected to an overhead line 5 and a rail 6, the transformation ratio is 4:1, the primary side voltage is 110kV, and the secondary side voltage is 27.5kV.
It should be noted that the overhead line ice melting system for rail transit further comprises an ice melting monitoring device and a controller, wherein the ice melting monitoring device is arranged in the traction substation and is used for monitoring ice coating data and environment data of the overhead line in real time, when the monitored ice coating data reach a threshold value, the controller calculates current required by the ice melting device for melting ice according to the received real-time monitoring data of the ice melting monitoring device and then sends a control signal to the ice melting device, and the ice melting device receives the control signal and generates capacitive reactive current to complete the ice melting process.
In this embodiment, the ice coating data includes at least an ice melting line terminal voltage, an ice melting line current, an ice melting line power, an ice melting line temperature, and an operation state of the ice melting device.
In fig. 2, the first ice melting device 10 and the second ice melting device 13 may be SVG, MCR or TCR, and one of the three may meet the ice melting requirement, and the first ice melting device 10 and the second ice melting device 13 are installed in the partition 8 and connected in parallel with the contact net 5; the two ends of the first ice melting device 10 are respectively connected in parallel with the contact net 5 through a first relay 11 and a second relay 12.
The first ice-melting device 10 and the second ice-melting device 13 are installed and connected in the partition 8 in the same manner.
SVG is equivalent to a variable reactive current source, the reactive current of the SVG can quickly change along with the change of the reactive current of a load, the SVG automatically compensates the reactive power required by a system, the SVG almost generates no harmonic wave when compensating the reactive power of the system, and the SVG can also perform multifunctional comprehensive compensation on the power quality problems such as harmonic wave, unbalance and the like of the system. The MCR, magnetic control dynamic reactive power compensation device, namely connect a set of magnetic control reactor in parallel on the general capacitor bank, through changing the direct current of the reactor and controlling the exciting current of the winding, change the inductance of the winding, achieve the goal of changing the reactive power absorbed by it. TCR, phase control type dynamic reactive power compensation device, namely connect a set of phase control reactor in parallel on the general capacitor bank, it can be through adjusting the trigger delay angle of the thyristor in TCR to adjust the reactive power of the compensation device continuously.
When the rail transit overhead contact system needs to melt ice, the ice melting device is switched to an ice melting working condition and forms an ice melting current loop through an ice melting line to melt ice, so that the overhead contact system is subjected to ice melting operation; when the rail transit contact net does not need to melt ice, the ice melting device is used as a reactive compensation device to perform reactive compensation on the contact net line, and the electric energy quality of the rail transit contact net is improved.
In the process of melting ice, a part of the ice coating is melted first, and the temperature of the exposed wire is not higher than the maximum allowable working temperature, so that the device is damaged due to overheating, and therefore, the area with extremely uneven thickness of the ice coating of the overhead line system is decomposed into a plurality of parts for melting ice.
In fig. 2, when the line ab section needs to be iced, the first ice melting device 10 is controlled to generate capacitive reactive power, capacitive alternating current is injected, a current loop is formed through the ice melting line, the first ice melting device 10, the secondary side of the transformer T2 and the steel rail 6, and the ice is melted by using heat generated by the current, that is, the ice is melted by converting electric energy into heat energy. If the bc section needs to melt ice, the steps are the same as the above process, in the process of melting ice, the line current is only increased between the lines to be melted ice, and the lines outside the melted ice area are not affected, so that uninterrupted online melting ice is realized.
According to the embodiment, the characteristics of the rail transit traction power supply specificity and the rail transit electrified operation are considered, the self-voltage of the overhead contact system is utilized, the current of the ice melting section line is increased by throwing the ice melting device into the ice melting section line under the condition that the load size is not changed, ice coating on the wire is removed in a self-heating mode when the wire runs under a heavy load or a full load state, the normal operation of the rail transit is not affected in the whole ice melting process, and uninterrupted ice melting of the overhead contact system is realized.
The embodiment can realize the online uninterrupted ice melting of the alternating current of the track traffic overhead line system without depending on an additional ice melting power system, simplify ice melting equipment, realize the immobilized configuration of the ice melting equipment, and rapidly and conveniently carry out the ice melting of the distribution network line. In the coming season of the ice and snow climate, an alternating current online uninterrupted ice melting device is adopted to realize online running ice melting, so that uninterrupted ice melting and uninterrupted power of the line in the ice and snow season are realized, normal power supply of the track traffic overhead contact system is ensured, and ice disaster faults such as bar falling and line breakage and the like do not occur in the track traffic overhead contact system in the ice and snow season; the embodiment can also prevent and control the icing of the line, combine the ice melting control console with the local weather forecast, and start anti-icing in advance before the icing of the line, so that the purpose of not icing the line is achieved.
Example two
The second embodiment of the invention introduces a control method of a catenary ice melting system for rail transit, and the catenary ice melting system for rail transit introduced in the first embodiment is adopted.
A control method of a catenary ice melting system for rail transit, comprising:
acquiring real-time icing data of a contact net line;
and controlling the working state of the ice melting device according to the acquired real-time icing data to finish ice melting of the overhead line system.
As one or more embodiments, when ice melting is needed, the controller calculates current required by the ice melting device for ice melting according to the received real-time monitoring data of the ice melting monitoring device, and then sends a control signal to the ice melting device, and the ice melting device generates capacitive reactive current after receiving the control signal, so as to perform ice melting operation of the overhead line system; when the deicing is not needed, the deicing device is used as a reactive compensation device to perform reactive compensation on the contact network line.
The detailed steps are the same as the working principle of the overhead line system ice melting system for rail transit provided in the first embodiment, and are not described herein again.
The above description is only a preferred embodiment of the present embodiment, and is not intended to limit the present embodiment, and various modifications and variations can be made to the present embodiment by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment should be included in the protection scope of the present embodiment.