CN116073311A - Anti-fusing detection and neutral section discharging method in neutral section ice melting process of overhead contact system - Google Patents

Abstract

The invention discloses an anti-fusing detection and neutral section discharging method in a neutral section ice melting process of a contact net, which comprises the following steps: the train running state monitoring and early warning module monitors the running state of the train of the peripheral power supply arm through a sensor, early warning is made when the train comes, and when the train does not exist, the switch control system is started to melt ice; the hanger anti-fusing detection module obtains the scope of hanger current by detecting the difference value of the carrier cable and the contact line current in the process of melting ice, so that the safety of the hanger in the process of melting ice is ensured; the neutral section grounding discharge device uses a vacuum circuit breaker to discharge the neutral section grounding after deicing. The invention effectively increases the deicing range of the overhead contact system, ensures that the deicing process can not cause fusing hazard to the overhead contact system and ensures the stability of the power supply system.

Description

Anti-fusing detection and neutral section discharging method in neutral section ice melting process of overhead contact system

Technical Field

The invention belongs to the field of electrified rail transit, and particularly relates to a contact net deicing technology.

Background

The contact net is an important component of an electrified railway traction net, is hung on an electric railway line, and is of a chain-type or single-wire type structure which keeps a certain distance from a steel rail. Because of long-term exposure to the open air, is easily influenced by natural disasters such as low temperature rain, snow and ice. In recent years, along with the rapid growth of electrified railways in China, the railway lines extend to areas with various climates, and in low-temperature, high-humidity and high-altitude areas, the situation that the contact net is covered with ice is easier to occur, so that hard points of the contact net are increased, arc of the pantograph is enhanced, abrasion of a sliding plate of the pantograph is easily accelerated, even accidents such as arc scraping and the like are caused, power supply interruption is caused, the operation of an electric locomotive is blocked, meanwhile, mechanical load of a cable net structure is increased due to ice covering, and the clamping stagnation of a locator and a compensation device is caused, so that the normal operation of the electric train is influenced from multiple aspects.

The contact net ice coating is a natural phenomenon generated by the change of external meteorological conditions, and is a physical phenomenon commonly determined by factors such as temperature, humidity, cold-warm air convection, circulation and the like. When the moisture in the air is at zero or below, the moisture adheres to the surface of the overhead contact system and freezes, so that the phenomenon of icing of the overhead contact system is formed.

Because of the special structure of the contact line, the contact line is not easy to twist in the icing process. According to actual observation on site, compared with common power transmission line icing, the contact line is easier to form ice edges under the condition of icing. In addition, the weight born by equipment can be increased under the condition of ice coating of the overhead contact system, so that the suspended equipment of the overhead contact system bears larger vertical load at ordinary times, and meanwhile, the horizontal load of the overhead contact system is increased under the action of wind power, and the load can exceed a design value under the serious condition of ice coating, so that the overhead contact system is broken and even a prop is broken.

When an electric locomotive or a motor train unit train runs on an ice-covered line, a pantograph can be prevented from smoothly taking current from a contact line, and a large electric arc can be generated when the electric locomotive or the motor train unit train runs seriously, so that the contact line and the pantograph can be burnt by the electric arc, even serious faults of broken contact lines are caused, and driving safety is affected. In addition to threatening the contact wires, the resulting arc can severely burn the carbon sled of the pantograph. The pantograph is broken, so that the train is stopped.

The basic technical scheme of the existing overhead contact system adopts manual deicing, the deicing efficiency of the method is low, the working environment is bad, the life safety of workers is easy to be threatened, in addition, the other method is that larger current is conducted inside the overhead contact system, so that the temperature of the overhead contact system is increased, ice on the surface of the overhead contact system is melted, but because the diameter of a dropper of the overhead contact system is relatively smaller, the current is unevenly distributed inside the overhead contact system, local dropper fusing is easy to be caused in the electric heating process, the contact line is separated from a carrier cable, the contact line is seriously grounded, and the power supply system is short-circuited. Because of the arrangement of electric split phases in the traction power supply system, electric insulation exists between the neutral section and the overhead contact line, in the traditional electric heating deicing method, current does not pass through the neutral section when the overhead contact line is electrified, and a train is still threatened by icing and bow scraping when passing through the neutral section.

The power supply range from the substation to the adjacent subareas is called a power supply arm, and each substation is provided with a left power supply arm and a right power supply arm (except for a terminal substation). In normal operation, the upstream and downstream contact networks of one power supply arm are connected in parallel at the head end (substation) and the tail end (partition substation) (upstream and downstream power supply lines are led from the same bus in the substation). Worker's work

The power frequency AC single-phase electric traction power supply system mainly consists of a traction substation and a traction network, wherein the traction network carries out single-phase power supply and consists of a feeder line, a contact network, a track circuit, a return line and the like. To supply electric power to an electric locomotive, an opening/closing station, or the like efficiently and reliably. The rated voltage of the traction net is 25kV and the rated frequency is 50Hz. The loop formed by traction power supply is as follows: traction substation-contact net-electric locomotive-steel rail and earth-return line-traction substation.

In a single-phase alternating current electric railway system, an electric locomotive is powered by a single-phase power supply, and in order to balance loads of each phase of the electric system and reduce negative sequence influence, power supplies of traction substations need to be subjected to phase sequence rotation to be connected into the electric system, so that an electric phase splitting device is arranged on a contact net between the two traction substations. The electric split phase is generally arranged at the outlet of the traction substation and the tail end of the power supply arm and consists of a contact net part, a vehicle-mounted device, a ground signal device and the like. The electric phase separation mode is a device type electric phase separation mode and a joint type electric phase separation mode (also called an air gap type) so as to electrically isolate the neutral section from the contact net, and an anchor section joint type electric phase separation mode is generally adopted at present, so that hard points on the contact net are reduced, and the current-collecting characteristic of the bow net is improved.

Disclosure of Invention

Aiming at the problems of the current high-speed rail up-down power supply relation, the characteristics of the contact net structure and the contact net deicing method, the method aims at effectively increasing the contact net deicing range, ensuring that the melting process does not cause fusing hazard to the contact net system and ensuring the stability of the power supply system. The invention provides an anti-fusing detection and neutral section discharging method in the ice melting process of a neutral section of a contact net.

The invention relates to an anti-fusing detection and neutral section discharging method in a neutral section ice melting process of a contact net. The switch control system is a master controller for switching power supply, forming short circuit, protecting circuit and finishing the switching grounding discharge of ice melting and switching back to the original power supply in the ice melting process. The specific control process is as follows:

the train running state monitoring and early warning module monitors the running state of the train of the peripheral power supply arm through a sensor, and early warning is carried out when the train comes, so that safe ice melting is ensured when no train passes; when the train is not running, the switch control system is started to melt ice.

The hanger anti-fusing detection module is characterized in that the hanger anti-fusing detection module is used for detecting the difference value of the current of the carrier rope and the contact line in the ice melting process, if the mutation exceeds a detection critical value, an alarm signal and a mutation signal are transmitted into the switch control system to stop ice melting, so that the safety of the hanger in the ice melting process is ensured.

And after the neutral section is electrified and the neutral section non-electric area is electrified to melt ice, in order to prevent the overhead contact system from storing electric energy due to the capacitance effect of the neutral section after the overhead contact system is electrified and melted ice, the overhead contact system discharges the train when the train passes through the neutral section after the ice melting, and the neutral section is grounded and discharged by using a vacuum circuit breaker.

The overhead line system voltage switching device switches power supply from 27.5kV to 10kV provided by a traction substation in the ice melting process, and switches back to 27.5kV through voltage switching after the neutral section is discharged, so that the train normally runs after ice melting.

Under normal working conditions, two ends of the segmented insulator are in a 25kV high-voltage state through the high-voltage isolating switch and the electric connection part and equipotential, when the isolating switch is disconnected, the contact net at one end of the segmented insulator is in a non-electric state and is grounded, and an air gap between two guide plates of the segmented insulator and an insulating element bear the contact net to ground voltage. When the ice melting device works normally, the ice melting device cannot use current to generate heat to melt ice, after 27.5kV to 10kV are switched, the contact net and the neutral section form a closed circuit by the change-over switch, so that the ice melting work can be carried out by the current passing through the neutral section, the circuit can lose a normal current-carrying path, the circuit can be protected by a short-circuit contact line-neutral section short-circuit breaker around a load, accidents are prevented, and the safe operation of the ice melting process is ensured.

The ice melting process comprises the following steps: when the train is not arranged, a switch control system is started, an uplink and downlink short-circuiting device is controlled to short-circuit and close an uplink and downlink contact line, then a neutral section contact net short-circuiting device is closed, so that an uplink contact net feeder line is connected with a 10kV high-voltage bus of the transformer substation, a downlink contact net feeder line is connected with a 10kV grounding bus of the transformer substation, and then a 10kV circuit breaker of the transformer substation is closed, so that the whole neutral section forms a loop, and ice melting work is carried out; after the ice melting is finished, releasing the electric energy accumulated in the neutral section due to the capacitance effect in the ice melting process through a neutral section discharging device, so as to prevent the occurrence of danger when a train passes; after the neutral section returns to the uncharged state again, the neutral section contact net shorting device and the neutral section discharging device enable the whole to be restored to the working state when the train normally runs through the up-down shorting device, and 27.5kV power is supplied.

The beneficial technical effects of the invention are as follows:

1. the invention provides an anti-fusing detection device which is calculated according to the current difference value of a contact line and a carrier cable, and considers the accident that a dropper is fused in the heating and deicing process of a contact network. In the conventional deicing process, the dropper is fused when being heated due to uneven current distribution caused by contact net material parameters. The anti-fusing detection device provided by the invention can obtain the current value of the hanger wire through calculating the current difference value of the contact wire and the carrier cable and through related calculation, and then compare the current value with the safety value, so that the ice melting can be ensured to be carried out in the safety range. Thereby greatly reducing the occurrence of fusing accidents of the dropper.

2. The invention has wider application range, and adopts 10kV voltage heating power supply of the traction substation. Compared with the traditional ice melting method adopting manual work or heavy current, the invention adopts 10kV voltage provided by lighting power supply of the traction substation for heating. In a railway system, a power substation is arranged in a distance of 40-60km according to the load, and each power substation is provided with a left power supply arm and a right power supply arm except a terminal power substation. Because the traction substation is uniformly and widely distributed, the traction substation is used for supplying power for melting ice, so that the power supply range can be ensured to be wider and more stable.

3. The invention designs the neutral section grounding discharge device, which reduces accumulation of electric energy of the neutral section caused by capacitance effect of the neutral section after charging and heating, so that voltage impact is generated to threaten the vehicle-mounted traction system when the train passes through the split phase. After deicing is performed by using illumination power supply of the traction substation, the original neutral section dead zone can store electric energy in the deicing process due to capacitance effect, so that discharge occurs when a subsequent train passes through the neutral section, and a traction system of the train is affected. The neutral section grounding discharge device is added, and the neutral section is discharged through the control switch, so that the neutral section is changed into a non-electric area again, and the normal running of the train is ensured.

4. The overhead contact line breaker realizes simultaneous deicing of the uplink and downlink contact lines and the neutral section, and has higher deicing efficiency and wider deicing range. In the traditional deicing technology, simultaneous deicing of an uplink contact line, a downlink contact line and a neutral section cannot be guaranteed, and the efficiency is low. In the invention, an uplink contact net feeder line is creatively connected with a 10kV high-voltage bus of a transformer substation, a downlink contact net feeder line is connected with a 10kV reflux bus of the transformer substation, and the uplink and downlink contact net at the far end of the contact net are in short circuit with a neutral section, so that an electric split-phase, a neutral section non-electric area and the contact net can be deiced through switch control. This results in a more efficient and broader range of overall deicing.

Drawings

Fig. 1 is an electrical phase separation schematic diagram of a catenary.

Fig. 2 is a schematic diagram of a catenary-electric split-phase ice coating and a cross-section thereof.

Fig. 3 is a switching diagram of the ice melting power supply system.

Fig. 4 is a system diagram of a dropper anti-fusing detection and neutral section discharging method in the neutral section ice melting process of the overhead contact system.

Fig. 5 is a circuit diagram of the neutral section of the catenary of the present invention in a normal state and an ice-melt state.

Fig. 6 is a flow chart of the anti-fusing detection and neutral section discharging method in the neutral section ice melting process of the overhead contact system.

Reference numerals are defined as follows: 1-a three-phase power grid; 2-a traction substation; 3-a phase supply line; 4-B phase supply line; 5-sucking up the wire; 6-rail; 7-segment insulators; 8-standing a pole; 9-cantilever support; 10-insulating means; 11-carrier ropes; 12-contacting the net; 13-hanging strings; 14-pantograph; 15-cross section of the contact net; 16-icing; 17-a carrier cable dropper wire clamp; 18-connecting terminals; 19-heart-shaped caulking rings; 20-connecting a pressure pipe; 21-a dropper wire; 22-a contact wire dropper wire clamp; 23-a train operation sensing module; 24-a dropper fusing prevention detection module; 25-neutral section grounding discharge control device; 26-a dropper fusing prevention detection device; 27-a neutral section contact net short-circuit device; 28-neutral section discharge means; 29-an up-down short-circuiting device; 30-a contact net voltage switching device; 31-a train running state monitoring and early warning module; 32-a switch control system; 33-a control box; 34-up contact line; 35-an upstream negative feed line; 36-a downlink contact line; 37-downstream negative feed line; 38-neutral section; 39-three-way breaker; a 40-10kV transformer; 41-27.5kV transformers; S1/S2-three-way breaker switch; the QS1/QS 2-transformer lead is connected with the switch through the uplink and downlink negative feeder lines; QS3/QS 4-neutral section and up-down contact line switch; QS5/QS 7-up-down contact line grounding discharge switch; QS 6-up and down contact line link switch.

Detailed Description

The invention will be described in further detail with reference to the accompanying drawings and the detailed description.

The overall structure of the catenary-electric phase separation at the neutral section between two traction substations when the train is running is shown in fig. 1. The traction substation consists of a three-phase power grid 1, a traction substation 2, an A-phase power supply line 3, a B-phase power supply line 4 and a suction line 5. The electricity generated by the power station enters a traction substation 2 connected with the power station through a three-phase power grid 1, the traction substation 2 is connected with an A-phase power supply line 3, a B-phase power supply line 4 and an upper suction line 5, and meanwhile, a steel rail 6 is connected with the traction substation 2 through the upper suction line 5. Between the two traction substations, an a-phase supply line 3 and a B-phase supply line 4, there are two segment insulators 7. The two segmented insulators and the dead zone between them constitute a zonal station, i.e. a zone where deicing of the neutral section is required.

The schematic cross-sectional view of the local structure of the railway traction power supply contact net-electric phase separation and the ice coating area formed by the contact net electric phase separation at low temperature, high altitude and high wind speed is shown in fig. 2 under the running condition of the train. On the train route there are a number of uprights 8 for supporting the whole traction power supply system. The insulating means 10 are connected to the pole 1 by means of a cantilever support 9, the function of which is to ensure the electrical insulation of the pole 8 from the supply line, preventing the current from flowing into the ground. The whole structure of the overhead contact system consists of a carrier rope 11, an overhead contact system 12, a dropper 13 and a pantograph 14. The carrier cable 11 is connected to the insulation device 10 and is an important conductor for the transmission and suspension of the contact network 10. The hanger 13 hangs the contact net 13 on the carrier cable 11. The pantograph 14 located on the train transmits the electric power output from the traction substation to the train and provides electric power for the train to travel by taking electricity from the overhead contact line 12. The cross section of the ice coating of the neutral section is shown in the oval dotted line frame of fig. 2. There is ice coating that has not been removed on the neutral section catenary 12, and it is observed that the cross section of catenary 12 is not regularly circular on catenary cross section 15, and the ice coating thickness of ice coating 16 is also different on the catenary cross section. Therefore, the melting time and voltage need to be considered in the melting process to prevent the phenomena of incomplete melting and melting of the contact net 12.

Fig. 3 is a switching diagram of the ice melting power supply system. The whole overhead line-neutral section ice melting system consists of a dropper releasing and fusing module, a train running sensing module 23 (namely a train running state monitoring and early warning system 31), a neutral section grounding discharge control device 25, an uplink and downlink short-circuiting device 29 (comprising a control box 33), an overhead line voltage switching device 30 and a switch control system 32.

Fig. 4 is a system diagram of a dropper anti-fusing detection and neutral section discharging method in the process of melting ice in a contact network-neutral section, and the overall circuit structure can be seen by observing a circuit diagram of the system diagram of the dropper anti-fusing detection and neutral section discharging method in the process of melting ice in a contact network-neutral section, and the specific circuit structure and switching relationship under normal working conditions and ice melting working conditions are illustrated in more detail in fig. 5. The specific structure of the hanger is as follows: the carrier cable and string clamps 17 connect the carrier cable and string, and the wire terminals 18 are immediately below the carrier cable string clamps 17. The lower part of the wiring terminal 18 is connected with a heart-shaped caulking ring 19, a string 21 and the heart-shaped caulking ring 19 are connected through a connecting pressure pipe 20, the string 21 is connected with a contact line string clamp 22, and an S-shaped neutral pile structure is integrally formed so as to ensure the connection stability of a carrier cable and a contact line.

In the overall structure, the train operation sensing module 23 is connected to a traction substation of 27.5kV, and whether a train passes through the ice melting section is ensured by reading parameters and train operation scheduling of the railway network. If the train is predicted to pass through the deicing section in the deicing process, if the icing condition is not suitable for the vehicle to pass through, the vehicle needs to wait for the deicing to finish and then pass through, and if the icing is not serious and does not influence the normal running of the vehicle, the vehicle is waited to run away from the icing section and then deicing is carried out. And cutting the up-down contact net from 27.5kV. Next, by controlling the up-down shorting device 29, the up-down shorting devices of the contact lines 34 and 36 are closed, and then the shorting device of the contact line-neutral section is closed, so that the up-line contact line feeder is connected with the 10kV high-voltage bus of the transformer substation, the down-line contact line feeder is connected with the 10kV grounding bus of the transformer substation, and then the 10kV circuit breaker of the transformer substation is closed, so that the neutral section integrally forms a loop, and ice melting work can be performed. The hanger wire fusing device is connected to the connection part of the 10kV transformer substation and the hanger wire, and whether the difference value of the currents at the upper end and the lower end of the hanger wire is within a specified threshold value is detected at any time so as to prevent the hanger wire from fusing. If the current interpolation at the upper end and the lower end exceeds a specified threshold value, the connection with the 10kV transformer is immediately disconnected, and the neutral section cable is waited for self-cooling. If there is no risk of melting during the ice melting, the ice melting is ended after a prescribed time for ice melting is reached. After the ice melting is finished, the electric energy accumulated in the neutral section due to the capacitance effect in the ice melting process is released through the neutral section discharging device 28, so that the danger is prevented when the train passes. After the neutral section returns to the uncharged state again, the neutral section contact net shorting device 27 and the neutral section discharging device 28 enable the whole to be restored to the working state when the train normally runs through the up-down shorting device 29, and 27.5kV is supplied with power.

Fig. 5 is a circuit diagram of the catenary-neutral section in a normal state and an ice-melt state. The circuit diagram of the ice melting system consists of a 27.5kV transformer 41, a 10kV transformer 40, three-way circuit breakers 39, S1 and S2-way circuit breaker switches, QS1 and QS 2-transformer lead and uplink and downlink negative feeder line connection switches, QS3 and QS 4-neutral sections and uplink and downlink contact line switches, QS5 and QS 7-uplink and downlink contact line grounding discharge switches, QS 6-uplink and downlink contact line link switches, uplink and downlink contact lines 34 and 36, an uplink negative feeder line 35 37 and a neutral section 38. Under normal state, the three-way breaker switch S1S2 selects two ports a and d to be connected with the 27.5kV transformer 41 so as to ensure the power supply requirement of the normal operation of the train, the QS1 and QS 2-transformer leads and the upper and lower negative feeder line connecting switches are in a closed state, and meanwhile, the QS3 and QS 4-neutral sections, the upper and lower contact line switches, the QS5/QS 7-upper and lower contact line grounding discharge switches and the QS 6-upper and lower contact line connecting switches are kept in an open state so as to ensure that current does not flow through the neutral section 38 and the integral operation of the train is not influenced. In the ice-melting state, three-way breaker switches S1 and S2 select two ports b and c, and are connected with the 10kV transformer 40. And both the S1, QS 2-transformer conductors and the up and down negative feeder connection switches are in an off state so that current can flow into the up and down contact lines 34, 36. Meanwhile, QS3 and QS 4-neutral sections, an up-down contact line switch and a QS 6-up-down contact line link switch are in a closed state, and QS5 and QS 7-up-down contact line grounding discharge switches are in an open state, so that a loop is formed between the neutral section 38 and the 10kV transformer, and ice melting operation of the neutral section 38 can be performed through heat energy generated by current. After the ice melting is finished, the electric energy storage device is switched to a normal state, and at the moment, the QS5 and QS 7-up and down contact line grounding discharging switches are in a closed state and used for releasing the electric energy stored in the neutral section 38 in the charging process, so that the traction system is prevented from being failed due to the electric energy stored in the neutral section 38 when the train is in normal running.

Fig. 6 is a flowchart of an anti-fusing detection and neutral section discharging method in the neutral section ice melting process of the overhead contact system, and the specific flow is as follows:

before ice melting begins, train running state monitoring information needs to be called to detect whether high-speed rail passes in the working time of the ice removing section. If no high-speed rail passes through the working time, the upper and lower contact networks are cut off from 27.5kV high voltage of the substation, and if the high-speed rail passes through the working time, the upper and lower contact networks are cut off from 27.5kV after the high-speed rail train passes through the deicing section. And the next step, the short-circuiting device of the contact line-neutral section is closed through a control switch, and then the short-circuiting device of the uplink contact line and the downlink contact line is closed, so that the uplink contact line feeder is connected with a 10kV high-voltage bus of the transformer substation, the downlink contact line feeder is connected with a 10kV grounding bus of the transformer substation, and then a 10kV circuit breaker of the transformer substation is closed, so that the whole neutral section forms a loop, and ice melting work can be carried out.

When deicing is carried out, two parameters are detected, namely specific heating time and currents at the upper end and the lower end of the hanger. After the ice melting starts, the dropper anti-fusing detection device 26 keeps working all the time, and detects whether the difference value of the currents at the upper end and the lower end of the dropper is within a specified threshold value or not at any time so as to prevent the dropper from fusing. If the current difference value is found to be not in the threshold value range at the moment, the 10kV circuit breaker of the transformer substation is immediately opened, a period of time is waited, the 10kV circuit breaker of the transformer substation is closed again after the neutral section cable is cooled to a specified temperature, and deicing operation is continued. In the heating process, specific heating time needs to be detected, if the difference value of the currents at the upper end and the lower end of the hanger is always within a specified threshold value during heating, heating is kept until the specified time is over, and if the specified time is not reached, heating and deicing are kept.

After heating, disconnecting the contact net from a 10kV bus, starting a neutral section grounding discharge device, discharging electric energy stored in the neutral section, disconnecting a contact line-neutral section short-circuiting device, and disconnecting an up-down contact net short-circuiting device. And (3) reconnecting the feeder lines of the uplink and downlink contact networks back to the 27.5kV cable of the substation, thereby completing the whole deicing work.

Claims (2)

1. The anti-fusing detection and neutral section discharging method for the ice melting process of the neutral section of the overhead line system is characterized in that the adopted system comprises a hanger anti-fusing detection module (24), a neutral section grounding discharging control device (25), a neutral section overhead line system short-circuiting device (27), a neutral section discharging device (28), an uplink and downlink short-circuiting device (29), an overhead line system voltage switching device (30), a train running state monitoring and early-warning module (31) and a switch control system (32); the switch control system (32) is a master controller for switching power supply, forming short circuit, protecting circuit and finishing the switching grounding discharge of ice melting and switching back to the original power supply in the ice melting process; the specific control process is as follows:

the train running state monitoring and early warning module (31) monitors the running state of the train of the peripheral power supply arm through a sensor, and early warning is carried out when the train comes, so that safe ice melting is ensured when no train passes; when the train is not running, the switch control system (32) is started to melt ice;

the hanger anti-fusing detection module (24) obtains the range of hanger current by detecting the difference value of the carrier cable and the contact line current in the ice melting process, and if the mutation exceeds a detection critical value, an alarm signal and a mutation signal are transmitted into the switch control system (32), so that ice melting is stopped, and the safety of the hanger in the ice melting process is ensured;

the neutral section grounding discharge control device (25) is used for preventing the overhead line system from storing electric energy due to the capacitance effect of the neutral section after the overhead line system is electrified and thawed after the neutral section no-electric area is electrified and thawed, so that the overhead line system discharges the train when the train passes through the neutral section after the ice is thawed, and the neutral section is grounded and discharged by using the vacuum circuit breaker;

and the overhead line system voltage switching device (30) is used for switching power supply from 27.5kV to 10kV provided by the traction substation in the ice melting process, and switching back to 27.5kV through voltage switching after the neutral section is discharged.

2. The method for detecting anti-fusing and neutral section discharging in the neutral section ice melting process of the overhead contact system according to claim 1, wherein the ice melting process is specifically as follows: when a train is not arranged, a switch control system (32) is started, an uplink and downlink short-circuiting device (29) is controlled to short-circuit and close an uplink and downlink contact line, a neutral section contact net short-circuiting device (27) is closed, an uplink contact net feeder line is connected with a 10kV high-voltage bus of the transformer substation, a downlink contact net feeder line is connected with a 10kV grounding bus of the transformer substation, a 10kV circuit breaker of the transformer substation is closed, and a neutral section integrally forms a loop to carry out ice melting; after the ice melting is finished, releasing the electric energy accumulated in the neutral section due to the capacitance effect in the ice melting process through a neutral section discharging device (28) to prevent the danger when the train passes; after the neutral section returns to the uncharged state again, the neutral section contact net short-circuiting device (27) and the neutral section discharging device (28) enable the whole to recover to the working state when the train normally runs through the up-down short-circuiting device (29), and 27.5kV is supplied with power.

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