A combined flexible automatic phase-crossing device for electrified railways and its control method

Abstract

This invention discloses a combined flexible automatic phase-crossing device for electrified railways and its control method, comprising a DC bus DB, an AC bus BL, an AC bus BR, a controller MC, at least one AC-DC converter AD1, at least one AC-DC converter AD2, at least one AC-DC converter AD3, and at least one AC-DC converter AD4. The DC ports of the AC-DC converters AD1, AD2, AD3, and AD4 are all connected to the DC bus DB. The AC ports of the AC-DC converters AD1, AD2, AD3, and AD4 are respectively connected to the AC bus BL, the upstream neutral section N1, the downstream neutral section N2, and the AC bus BR. This topology, where the left and right power supplies share a DC bus with the n AC-DC converters, facilitates the combination of AC-DC converters into AC-AC converters to achieve power supply, control, and switching for the locomotive in the neutral section. It also facilitates expansion. The AC-DC-AC combination, where the left and right power supply sides share a common supply and the neutral section supplies power separately, achieves maximum combined functionality with the fewest AC-DC converters, thus reducing the cost of the device.

Description

Technical Field

[0001] This invention relates to the field of traction power supply circuit design for electrified railways, and particularly to the design of flexible automatic phase-separation power supply circuits for electrified railways and circuit control methods for normal and fault states. Background Technology

[0002] In my country, electrified railways generally use a single-phase power frequency AC system. To ensure that the three-phase load of the power system is as balanced as possible, electrified railway circuit design often adopts a scheme of alternating phase sequence and phase-separated zone power supply. The circuits of adjacent power supply sections at the phase separation zone are separated by air or insulators, which is referred to as electrical phase separation or phase separation.

[0003] Currently, the commonly used automatic phase crossing methods can be divided into two types: on-board automatic phase crossing and ground-based automatic phase crossing. Ground-based automatic phase crossing is mainly divided into switch-type ground-based automatic phase crossing and flexible automatic phase crossing. However, regardless of whether it is on-board automatic phase crossing or switch-type ground-based automatic phase crossing, the switching process will generate transient processes, which can easily cause operational overvoltage, overcurrent, and arcing problems caused by the interruption of pantograph-catenary current, and even damage components, cause malfunctions, and threaten the safe and reliable operation of trains.

[0004] For flexible automatic phase transition technology, the key to the success or failure of its circuit design is the distribution of locomotive power in the transition zone between the train and the overhead contact line and the neutral zone (stage 2 below). The key is whether the current (power) of the overhead contact line can be reduced to 0 when the locomotive leaves the transition zone. The technical means used is to add an AC-DC-AC power supply branch in the transition zone, in addition to the overhead contact line. The AC-DC-AC power supply branch is used to transfer electrical energy from the power supply arm to the neutral zone, ensuring that the train is powered throughout the phase transition process and suppressing transient problems. The current research is basically divided into 7 stages: Stage 1: Controlling the neutral line voltage to be consistent with the voltage of power supply arm a; Stage 2: Gradually increasing the output power of the AC-DC-AC power supply branch to the power required by the locomotive, with no current transmission between the pantograph and power supply arm a during separation, avoiding transient problems caused by current segmentation of the pantograph-catenary circuit; Stage 3: The AC-DC-AC power supply branch supplies power to the locomotive, with the neutral line voltage consistent with the voltage of power supply arm a; Stage 4: The AC-DC-AC power supply branch adjusts the voltage to switch the neutral line voltage to power supply arm b; Stage 5: The AC-DC-AC power supply branch supplies power to the locomotive, with the neutral line voltage consistent with the voltage of power supply arm b; Stage 6: The locomotive switches from being powered only by the AC-DC-AC power supply branch to being powered only by power supply arm b, with no current transmission during pantograph-catenary circuit separation (the catenary here refers to the neutral line), avoiding transient problems caused by current segmentation; Stage 7: The AC-DC-AC power supply branch does not output power, and the output voltage follows power supply arm b; where power supply arms a and b are located on the left and right sides of the electrical phase separation. However, the existing technology is too cumbersome to control and adjust the sixth stage of the overhead contact line closing phase, which increases the difficulty of the locomotive automatically crossing the phase.

[0005] According to the power source of the newly added AC-DC-AC power supply branch, the locomotive running direction, and the electrified railway traction network line model, the existing flexible automatic phase transition technology circuit design can be divided into: (1) The power supply of the AC-DC-AC power supply branch comes from the contact network in front of the locomotive. As recorded in Chinese Patent ZL201510557576.2 and the article "Research on Flexible Phase Transition Full Parallel AT Traction Network Protection Scheme", the principle is that the power supply of the contact network branch comes from the U phase, and the power supply of the AC-DC-AC power supply branch comes from the V phase. In the transition zone, the power of the locomotive is distributed by the branch from the V phase (another power source). (2) The power supply of the AC-DC-AC power supply branch comes from the contact network behind the locomotive. As described in the literature "Investigation of Closing Surge in Shinkansen Power System and Proposal of a Novel Power Electronics Application for Changeover Section," the principle is that the power supply for both the overhead contact line branch and the AC / DC / AC power supply branch comes from the same phase. In the transition zone, the AC / DC / AC power supply branch from the same phase distributes the locomotive power. However, the overhead contact line branch is very short, almost bypassing the AC / DC / AC power supply branch, which increases the difficulty of distributing the locomotive power. As mentioned in the text, during the test, the pantograph experienced a momentary overcurrent when it was first connected to the CSPS system, but this was not observed in the simulation.

[0006] Furthermore, the limitations on residual current that could lead to arcing and locomotive damage in practical applications are still unclear and require future discussion and resolution.

[0007] Currently, research on flexible automatic phase-crossing technology is mostly focused on single-track electrified railways, such as the articles published by Tsinghua University, "Research on Automatic Phase-Crossing Scheme Without Power Outage in Electrified Railways" and "Research on Phase-Crossing and Power Quality Compensation Devices for Electrified Railways Without Power Outage." However, research on flexible automatic phase-crossing technology for double-track electrified railways is scarce. Yet, with the rapid increase in the demand for electrified railway transportation, double-track electrified railways, which can significantly increase the transportation capacity of electrified railways, have become the main development direction for electrified railways in my country. Existing double-track electrified railways are extensions of single-track electrified railways, generally with flexible phase-crossing devices installed on the up and down lines respectively. The operation mode is singular; the up and down phase-crossings are electrically independent and operate separately. This cannot solve the problem of locomotive phase-crossing operation in the event of a neutral section fault. If the flexible phase-crossing device fails, the locomotives on the corresponding line will be unable to automatically cross the phase normally, resulting in low system reliability. Furthermore, if the entire flexible phase-crossing device is kept on standby, it will increase costs. Following their work on uninterrupted phase-crossing in single-track electrified railways, Tsinghua University published an article titled "Research on Uninterrupted Phase-Crossing and Power Quality Compensation Devices for Double-Track Traction Networks." In this study, the up and down α-phase converters share the up-line β-phase converter. Locomotives in both directions can only operate on their respective up or down lines within the phase-crossing zone. Furthermore, this T-connection topology limits the reliability of the flexible phase-crossing devices in both directions to the up-line β-phase converter, resulting in a single operating mode and hindering separate control and operation of the up and down electrified railways. Simultaneously, existing flexible automatic phase-crossing devices still rely on switches to control locomotive entry and exit from the phase-crossing zone, impacting system lifespan and threatening safe and reliable train operation. In short, existing flexible phase-crossing devices have limited applicability, fixed operating modes, low reliability, are difficult to expand, have high investment costs, and cannot meet the needs of locomotive operation under different conditions and states for the overhead contact system and flexible phase-crossing devices. The system lifespan issues caused by switch switching also persist. Summary of the Invention

[0008] (I) Flexible automatic phase-crossing device and double-track traction power supply system

[0009] The first objective of this invention is to provide a combined flexible automatic phase-crossing device for double-track electrified railways. This device can be installed in either traction substations or sectioning stations. It boasts powerful system functions, flexible operation, and facilitates the combination and expansion of AC / DC converters. It is technically reliable and easy to implement. It achieves maximum combined functionality with a minimal number of AC / DC converters, enabling power supply, control, and switching for locomotives in the neutral section, resulting in low investment costs. It is applicable to both double-track and single-track electrified railways, allowing locomotives to automatically cross phases without power interruption regardless of the contact network or the flexible phase-crossing device's operating conditions and states. It also features negative sequence mitigation and power accommodating capabilities between the two traction networks. All operating modes and their transitions do not require operation of feeder switches, thus not affecting system lifespan and ensuring high reliability. This invention effectively solves the problems of existing flexible phase-crossing devices, such as limited applicability, fixed operation modes, low reliability, limited expansion capabilities, high investment costs, inability to meet various locomotive operating conditions, and system lifespan issues caused by switch switching.

[0010] A combined flexible automatic phase-crossing device includes a DC bus DB, an AC bus BL, an AC bus BR, a controller MC, at least one AC-DC converter AD1, at least one AC-DC converter AD2, at least one AC-DC converter AD3, and at least one AC-DC converter AD4, wherein...

[0011] One end of the AC port of the AC-DC converter AD1 is connected to the AC bus BL, and the other end is grounded; the AC bus BL is provided with two lead-out terminals, which serve as the input / output terminals A11 and A12 of the combined flexible automatic phase-crossing device, respectively.

[0012] One end of the AC port of the AC-DC converter AD2 serves as the input / output terminal A2 of the combined flexible automatic phase-crossing device for connection with the upstream neutral section N1, and the other end is grounded;

[0013] One end of the AC port of the AC-DC converter AD3 serves as the input / output terminal A3 of the combined flexible automatic phase-crossing device for connection to the downlink neutral section N2, and the other end is grounded;

[0014] One end of the AC port of the AC-DC converter AD4 is connected to the AC bus BR, and the other end is grounded; the AC bus BR is provided with two lead-out terminals, which serve as the input / output terminals A41 and A42 of the combined flexible automatic phase-crossing device, respectively.

[0015] The DC ports of AC-DC converters AD1, AD2, AD3, and AD4 are all connected to the DC bus DB. The input terminal of the controller MC is connected to the measurement terminal of the detection equipment, and the output terminal of the controller MC is connected to the control terminal of AC-DC converters AD1, AD2, AD3, and AD4.

[0016] Preferably, the two leads of the AC bus BL are connected to feeders F1 and F2 respectively, and a switch K1 is connected in series on feeder F1 and a switch K2 is connected in series on feeder F2.

[0017] Preferably, a switch KL is connected in series on the AC bus BL between the feeders F1 and F2.

[0018] Preferably, the two leads of the AC bus BR are connected to feeders F3 and F4 respectively, and a switch K3 is connected in series on feeder F3 and a switch K4 is connected in series on feeder F4.

[0019] Preferably, a switch KR is connected in series on the AC bus BR between feeders F3 and F4.

[0020] Preferably, one AC-DC converter AD1, one AC-DC converter AD2, one AC-DC converter AD3, and one AC-DC converter AD4 are each provided.

[0021] Preferably, it also includes a backup AC-DC converter B, which can serve as a backup for the AC-DC converters AD1, AD2, AD3, or AD4 under the control of the controller MC.

[0022] Preferably, AC-DC converters AD1, AD2, AD3, and AD4 have the same structure and the same capacity.

[0023] Preferably, the detection device includes:

[0024] Multiple train position identifiers for identifying train positions;

[0025] Multiple current transformers used to detect the current in the overhead contact line;

[0026] Multiple voltage transformers for detecting AC bus voltage;

[0027] The measuring terminals of the train position identifier, current transformer, and voltage transformer are all connected to the input terminal of the controller MC.

[0028] Preferably, the DC bus DB is a high-voltage DC bus or a low-voltage DC bus.

[0029] Preferably, AC-DC converters AD1, AD2, AD3, and AD4 are all equipped with reactors or matching transformers.

[0030] Preferably, the flexible automatic phase-separation device is installed in the electrical separation unit of the traction substation or in the electrical separation unit of the section substation.

[0031] Preferably, the AC bus BL and AC bus BR are two traction buses of a traction substation or two buses of a section substation.

[0032] Preferably, the AC bus BL and AC bus BR are taken from any two phases of A, B, and C of the three-phase power grid, or any two phases of AB, BC, and CA, respectively, wherein the phase angle difference between the AC bus BL and AC bus BR is 120°, 60°, or 90°; or the AC bus BL and AC bus BR are taken from the same phase of A, B, and C of the three-phase power grid, or the same phase of AB, BC, and CA, wherein the phase angle difference between the AC bus BL and AC bus BR is 0°.

[0033] A double-track traction power supply system includes the combined flexible automatic phase-crossing device, wherein the input / output terminals A11, A12, A41, and A42 of the combined flexible automatic phase-crossing device are respectively connected to the left upward contact network OCS11, the left downward contact network OCS21, the right upward contact network OCS12, and the right downward contact network OCS22.

[0034] Preferably, the detection device includes:

[0035] Current transformer CT1 is connected in series with the left-side up-line contact network OCS11 and is close to the connection point of feeder F1;

[0036] Current transformer CT2 is connected in series with the left-side down contact network OCS21 and is located near the feeder F2 connection point;

[0037] Current transformer CT3 is connected in series with the right-side up-line contact network OCS12 and is located near the feeder F3 connection point;

[0038] Current transformer CT4 is connected in series with the right-side down contact network OCS22 and is located near the feeder F4 connection point;

[0039] Voltage transformer PT1 connected in parallel to AC bus BL;

[0040] Voltage transformer PT2 is connected in parallel to AC bus BR.

[0041] Preferably, the double-track electrified railway is equipped with a crossover, which allows the up-line locomotive to transition from the up line to the down line, and the down-line locomotive to transition from the down line to the up line, performing a "V" stop and reverse movement.

[0042] This invention proposes a topology where power supplies on both sides and n AC / DC converters (at least one AC / DC converter AD1, at least one AC / DC converter AD2, at least one AC / DC converter AD3, and at least one AC / DC converter AD4) share a DC bus. This topology provides two power sources for the neutral section of an electrified railway: one from the left-side U-phase AC bus BL, and the other from the right-side V-phase AC bus BR. The U-phase and V-phase are the traction network phases on either side of the electrical phase separation, respectively. Simultaneously, the DC ports of all n AC / DC converters are connected to the same DC bus. This topology enables the AC / DC converters connected to the AC bus (hereinafter referred to as the power supply-side AC / DC converters) to share a DC bus with the power supply side AC / DC converters. The AC-DC converters in the up and down neutral sections (hereinafter referred to as neutral section AC-DC converters) are combined to supply power to the locomotives in the up and down neutral sections respectively. This allows the neutral section AC-DC converter AD2 to be combined with at least one of the AC-DC converters AD1 and AD4 on the power supply side to form a DC-AC converter to supply power to the up neutral section N1. The neutral section AC-DC converter AD3 can be combined with at least one of the AC-DC converters AD1 and AD4 on the power supply side to form a DC-AC converter to supply power to the down neutral section N2. The multiple combination structures allow the locomotive to be powered by the left U phase, the right V phase, or both power supplies when passing through the neutral section, making the operation flexible.

[0043] In this invention, the power supply source for the AC-DC converters on both sides of the power supply side is directly taken from the AC bus, instead of setting AC-DC converters on the upstream and downstream power supply arms on the left and right sides respectively. This allows the AC-DC converters on both sides of the power supply side to supply power to the upstream and downstream neutral sections. In other words, the AC-DC converters on the upstream and downstream neutral sections can share the AC-DC converters on both sides of the power supply side. This AC-DC-AC combination form, which uses the fewest AC-DC converters to achieve the maximum combination function, can reduce the cost of the device and overcome the shortcomings of the prior art, which sets AC-DC converters on the upstream and downstream power supply arms respectively, resulting in high investment costs.

[0044] The present invention provides that the AC-DC converter AD1 connected to the left U-phase power supply and the AC-DC converter AD4 connected to the right V-phase power supply serve as backups for each other. When the AC-DC converter on one power supply side fails, power can be supplied to the up and down locomotives through the AC-DC converter on the other power supply side, thereby not affecting the normal operation of the locomotives in the neutral section and improving the reliability of the system.

[0045] In this invention, the uplink neutral section N1 and the downlink neutral section N2 serve as backups for each other. When one of the uplink or downlink neutral sections fails, the locomotive can be powered by the other neutral section through the "V-stop reverse" operation mode of the overhead contact line in the neutral section. This allows the locomotive to safely and automatically pass through the phase transition without interrupting power, thus not affecting the normal operation of the locomotive and improving the reliability of the system.

[0046] This invention connects the left and right AC-DC converters AD1 and AD4 on the same DC bus, enabling the topology to simultaneously provide power quality management and power sharing between the two traction networks.

[0047] The flexible automatic phase-crossing device of the present invention is applicable to both double-track electrified railways and single-track electrified railways.

[0048] Each of the AC-DC converters AD1, AD2, AD3, and AD4 is provided at one time. This achieves maximum combined functionality using the fewest possible AC-DC converters, further reducing system operating costs.

[0049] Among them, the n AC-DC converters also include a neutral section backup AC-DC converter. The backup AC-DC converter is put into operation when the neutral section AC-DC converter AD2 or AD3 fails, ensuring that the locomotive automatically transitions through the phase without power interruption, and further improving the reliability of the system.

[0050] Among them, the n AC-DC converters have the same structure and equal capacity, which facilitates development, backup, and operation and maintenance.

[0051] The input terminal of the controller MC is connected to the measurement terminal of the detection equipment, and the output terminal of the controller MC is connected to the control terminals of n AC-DC converters. The controller MC is mainly used to receive signals and data from the detection equipment. By controlling the power output of the AC-DC converters, it realizes the transfer of electrical energy from the power supply arm to the neutral section and the energy transfer between the two power supply arms, enabling the train to automatically cross the phase without power interruption. When no train is passing through the neutral section, the controller controls the switching of the AC-DC converters on the left and right power supply sides, realizing the power quality management function of the two power supply arms and the power accommodation function of the traction networks on both sides. The controller achieves measurement, switching, adjustment, and control of the equipment, avoiding the system lifespan problems caused by switching in existing flexible phase-crossing technologies.

[0052] The detection equipment includes a train position identifier (TPI), current transformers, and voltage transformers. The TPI comprises multiple train position sensors and related power supply lines. The voltage transformers include PT1 and PT2, and the current transformers include CT1, CT2, CT3, and CT4. The TPI primarily identifies the train's position within a section of the electrified railway track, detecting whether a train has arrived at a designated location, its direction of travel, and whether the track section is occupied. It then generates a train section position signal from the processed signal and transmits it to the controller (MC). The voltage transformer PTn detects the AC bus voltage, and the current transformer CTn detects the power supply line current for system protection and measurement control. It also transmits the processed data to the controller (MC).

[0053] The left-side contact network of the phase separation includes the left-side up-line contact network OCS11 and the left-side down-line contact network OCS21, while the right-side contact network of the phase separation includes the right-side up-line contact network OCS12 and the right-side down-line contact network OCS22.

[0054] The left-side uplink contact network OCS11 and the left-side downlink contact network OCS21 are connected to the left-side U-phase AC bus BL via feeders F1 and F2, respectively. The right-side uplink contact network OCS12 and the right-side downlink contact network OCS22 are connected to the right-side V-phase AC bus BR via feeders F3 and F4, respectively. Switches K1, K2, K3, and K4 are installed on feeders F1, F2, F3, and F4, respectively. Current is drawn from the power supply arm via feeder Fn, and the switching of switch Kn determines whether the corresponding power supply arm is connected. This structure can control the system to operate in single-line or double-line mode, further increasing the flexibility of the operation.

[0055] Specifically, current transformer CT1 is connected in series to contact network OCS11, which leads to the upward neutral section N1 and is located near the connection point of feeder F1; current transformer CT2 is connected in series to contact network OCS21, which leads to the downward neutral section N2 and is located near the connection point of feeder F2; current transformer CT3 is connected in series to contact network OCS12, which leads to the upward neutral section N1 and is located near the connection point of feeder F3; current transformer CT4 is connected in series to contact network OCS22, which leads to the downward neutral section N2 and is located near the connection point of feeder F4; voltage transformer PT1 is connected to the left U-phase AC bus BL, and voltage transformer PT2 is connected to the right V-phase AC bus BR. This structure reduces the number of detection devices by setting up an AC bus and placing voltage transformers on it. The voltage transformer PTn is used to detect the AC bus voltage, overcoming the shortcomings of existing technologies that sequentially set voltage transformers on each power supply arm, resulting in redundant detection devices. The current transformer CTn is used to detect the current on the contact wire. The data measured by the voltage transformer and the current transformer are used by the control controller MC to ensure that the neutral section voltage does not change abruptly and that the current (power) when the locomotive leaves the contact wire is 0.

[0056] The left-side U-phase AC bus BL and the right-side V-phase AC bus BR are either two buses in a traction substation or two buses in a sectioning substation. This invention's combined electrified railway flexible automatic phase-crossing device can be installed in either a traction substation or a sectioning substation. Correspondingly, the left and right AC buses can be either two buses in a traction substation or two buses in a sectioning substation, thus solving the technical problem of uninterrupted automatic phase-crossing for locomotives at both traction substations and sectioning substations.

[0057] Wherein, the U phase and V phase are respectively taken from any two phases of A, B, and C of the three-phase power grid or any two phases of AB, BC, and CA, wherein the phase angle difference between the U phase and V phase is 120°, 60°, or 90°; or the U phase and V phase are taken from the same phase of A, B, and C of the three-phase power grid or the same phase of AB, BC, and CA, wherein the phase angle difference between the U phase and V phase is 0°. When the AC busbars on the left and right sides are the two busbars of the traction substation, the U phase and V phase are respectively taken from any two phases of A, B, and C of the three-phase power grid or any two phases of AB, BC, and CA. The phase angle difference between the U phase and V phase is 120°, 60°, or 90° to match the voltage on both sides of the traction substation. When the AC busbars on the left and right sides are the two busbars of the sectioning substation, the U phase and V phase are taken from the same phase of A, B, and C of the three-phase power grid or the same phase of AB, BC, and CA. The phase angle difference between the U phase and V phase is 0° to match the voltage on both sides of the sectioning substation.

[0058] The double-track electrified railway features a crossover, allowing up-line locomotives to travel from the up track to the down track, and down-line locomotives to travel from the down track to the up track, performing a "V" stop and reverse movement. This structure further ensures the smooth operation of locomotives in the event of a catenary failure on the double-track electrified railway.

[0059] (II) Normal Over-phase Control Method for Multi-line

[0060] The second objective of this invention is to provide a control method for the flexible automatic phase transition of locomotives on double-track electrified railways. Under the premise of ensuring that the locomotive automatically transitions through phases without interrupting power supply and avoiding arcing problems caused by overvoltage, overcurrent, and pantograph-catenary current disconnection, this method improves the complex contact wire closing process in the prior art, simplifies the control and adjustment process, and enables the locomotive to pass through the neutral section safely and conveniently.

[0061] A flexible automatic phase-crossing control method for double-track electrified railways based on the double-track traction power supply system, the control method including an automatic phase-crossing control mode for up-line locomotives and an automatic phase-crossing control mode for down-line locomotives.

[0062] Preferably, in the automatic phase-crossing control mode for the up-traveling locomotive, the control method includes:

[0063] First, obtain the position information of the uplink locomotive and determine whether the uplink locomotive is about to enter the transition area Z11. If so, control at least one of the AC-DC converters AD1 and AD4 to work together with the AC-DC converter AD2 so that the AC port output of the AC converter AD2 is the same voltage as the left uplink contact network OCS11.

[0064] Second, obtain the location information of the uplink locomotive and determine whether the uplink locomotive has entered the transition area Z11. If so, continue to control the operation of the AC-DC converter that is currently running, so that the power output of the AC port of the AC-DC converter AD2 gradually increases from 0 to the locomotive power of the left uplink contact network OCS11.

[0065] 3. Obtain the position information of the uplink locomotive and determine whether the uplink locomotive is leaving the transition zone Z11. If so, when the uplink locomotive leaves the transition zone Z11, control the current obtained by the uplink neutral section N1 from the left-side uplink contact network OCS11 to be 0.

[0066] After leaving the transition zone Z11, continue to control the operation of the AC-DC converter that is currently running. While maintaining the output power unchanged, make the AC port of the AC-DC converter AD2 gradually output the same voltage as the right-side upward contact network OCS12 through phase shifting.

[0067] Fourth, obtain the location information of the uplink locomotive and determine whether the uplink locomotive has entered the transition zone Z12. If so, control the above-mentioned AC-DC converter that is currently in operation to stop, and the uplink locomotive will be powered by the right-side uplink contact network OCS12.

[0068] Preferably, in the automatic phase-crossing control mode for the downlink locomotive, the control method includes:

[0069] First, obtain the location information of the downlink locomotive and determine whether the downlink locomotive is about to enter the transition area Z22. If so, control at least one of the AC-DC converters AD1 and AD4 to work together with the AC-DC converter AD3 so that the AC port output of the AC converter AD3 is the same voltage as the right downlink contact network OCS22.

[0070] Second, obtain the location information of the downlink locomotive and determine whether the downlink locomotive has entered the transition area Z22. If so, continue to control the operation of the AC-DC converter that is currently running, so that the power output of the AC port of the AC-DC converter AD3 gradually increases from 0 to the locomotive power of the right downlink contact network OCS22.

[0071] 3. Obtain the location information of the downlink locomotive and determine whether the downlink locomotive is leaving the transition area Z22. If so, when the downlink locomotive leaves the transition area Z22, control the current obtained by the downlink neutral section N2 from the right downlink contact network OCS22 to be 0.

[0072] After leaving the transition zone Z22, continue to control the operation of the AC-DC converter that is currently in operation. While maintaining the output power unchanged, make the AC port of the AC-DC converter AD3 gradually output the same voltage as the left-downward contact network OCS21 through phase shifting.

[0073] Fourth, obtain the location information of the uplink locomotive and determine whether the downlink locomotive has entered the transition zone Z21. If so, control the above-mentioned AC-DC converter in operation to stop, and the downlink locomotive will be powered by the left downlink contact network OCS21.

[0074] Preferably, in the power fusion mode, the control method includes:

[0075] Determine whether there is an up-line or down-line locomotive about to undergo power phase switching. If not, control AC-DC converters AD1 and AD4 to work together to perform power switching control on the left up-line contact network OCS11 and the right up-line contact network OCS12, or to perform power switching control on the right down-line contact network OCS22 and the left down-line contact network OCS21.

[0076] Preferably, the controller MC calculates the locomotive power of the left-side up-line contact network OCS11 and the locomotive power of the left-side down-line contact network OCS21 using the input data from voltage transformer PT1 and current transformers CT1 and CT2, respectively; the controller MC calculates the locomotive power of the right-side up-line contact network OCS12 and the locomotive power of the right-side down-line contact network OCS22 using the input data from voltage transformer PT2 and current transformers CT3 and CT4, respectively.

[0077] Preferably, the controller MC detects the train position, train direction, and track occupancy status through a train position identifier.

[0078] The uplink neutral section N1 and downlink neutral section N2 operate normally. The uplink neutral section N1 includes a transition zone Z11 near the left uplink contact line OCS11 and a transition zone Z12 near the right uplink contact line OCS12. The downlink neutral section N2 includes a transition zone Z21 near the left downlink contact line OCS21 and a transition zone Z22 near the right downlink contact line OCS22. Uplink locomotives are powered by the right uplink contact line OCS12 in transition zone Z12, and downlink locomotives are powered by the left downlink contact line OCS21 in transition zone Z21.

[0079] (III) Over-phase control method for double-track "V-stop reverse"

[0080] The third objective of this invention is to provide a control method for "V-stop reverse operation" of locomotives on double-track electrified railways. This method effectively solves the problem of controlling the locomotive to automatically cross phases without power failure when either the upward neutral section N1 or the downward neutral section N2 fails. The upward neutral section N1 and the downward neutral section N2 serve as backups for each other. When one of the upward or downward neutral sections fails, the locomotive can be powered by the other neutral section through the "V-stop reverse operation" mode of the overhead contact system, enabling the locomotive to safely and automatically cross phases without power failure, thus not affecting the normal operation of the locomotive and improving the reliability of the system.

[0081] A "V-stop and reverse" control method for locomotives on double-track electrified railways based on the aforementioned double-track traction power supply system, wherein when a fault occurs in the neutral section N1 of the up-track line or the neutral section N2 of the down-track line, the locomotive uses the "V-stop and reverse" method to bypass the faulty section, comprising the following steps:

[0082] (1) When the upward neutral section N1 fails, the locomotive enters the left downward contact line OCS21 from the left upward contact line OCS11 before entering the upward neutral section N1. The control device MC is adjusted so that the locomotive can enter the downward neutral section N2 normally. The control device MC is adjusted so that the locomotive can exit the downward neutral section N2. After the locomotive exits the downward neutral section N2, it enters the right upward contact line OCS12 from the right downward contact line OCS22. The locomotive is powered by the right upward contact line OCS12.

[0083] (2) When the downlink neutral section N2 fails, the locomotive enters the right-side uplink contact line OCS12 from the right-side downlink contact line OCS22 before entering the downlink neutral section N2. The control device MC is adjusted to allow the locomotive to enter the uplink neutral section N1 normally. The control device MC is then adjusted to allow the locomotive to exit the uplink neutral section N1. After the locomotive exits the uplink neutral section N1, it enters the left-side downlink contact line OCS21 from the left-side uplink contact line OCS11. The locomotive is powered by the left-side downlink contact line OCS21.

[0084] Preferably, the uplink neutral section N1 includes a transition zone Z11 near the left-side uplink contact line OCS11 and a transition zone Z12 near the right-side uplink contact line OCS12, and the downlink neutral section N2 includes a transition zone Z21 near the left-side downlink contact line OCS21 and a transition zone Z22 near the right-side downlink contact line OCS22. In the transition zone Z11, the locomotive is powered by the contact line OCS11, and in the transition zone Z22, the locomotive is powered by the contact line OCS22.

[0085] Preferably, the step (1) of "adjusting the controller MC to allow the locomotive to normally enter the downlink neutral section N2, and continuing to adjust the controller MC to allow the locomotive to exit the downlink neutral section N2" includes: when the locomotive is about to enter the transition zone Z21 from the left, the controller MC controls at least one of the AC-DC converter three AD3 and AC-DC converter one AD1 and AC-DC converter four AD4 to operate, so that the AC port output of AC-DC converter three AD3 has the same voltage, the same magnitude, the same frequency, and the same phase angle as the contact network OCS21; when the locomotive enters the transition zone Z21 from the left, the controller MC continues to control the operation of the aforementioned AC-DC converters that are currently in operation, so that the AC port output of AC-DC converter three AD3 has the same voltage, the same frequency, and the same phase angle as the contact network OCS21; The power output from the AC port of the DC converter three AD3 gradually increases from 0 to the locomotive power of the contact wire OCS21. When the locomotive leaves the transition zone Z21, the current of the contact wire OCS21 becomes 0. Before the locomotive enters the transition zone Z22, the controller MC continues to control the operation of the AC-DC converter. While maintaining the output power, the AC port of the AC-DC converter three AD3 gradually outputs the same voltage, frequency, and phase angle as the contact wire OCS22 through phase shifting. When the locomotive enters the transition zone Z22 from the left, the controller MC controls the operation of the AC-DC converter to stop, and the locomotive is powered by the contact wire OCS22.

[0086] Preferably, step (2) of "adjusting the controller MC to allow the locomotive to normally enter the upward neutral section N1, and continuing to adjust the controller MC to allow the locomotive to exit the upward neutral section N1" includes: when the locomotive is about to enter the transition zone Z12 from the right, the controller MC controls at least one of the AC-DC converters AD2 and AD1 and AD4 to operate, so that the AC port output of AC converter AD2 has the same voltage, the same magnitude, the same frequency, and the same phase angle as the contact network OCS12; when the locomotive enters the transition zone Z12 from the right, the controller MC continues to control the operation of the aforementioned AC-DC converters, so that the AC port output of AC converter AD2 has the same voltage, the same frequency, and the same phase angle as the contact network OCS12; when the locomotive enters the transition zone Z12 from the right, the controller MC continues to control the operation of the aforementioned AC-DC converters, so that the AC port output of AC converter AD2 has the same voltage, the same frequency, and the same phase angle as the contact network OCS12; The power output from the AC port of DC converter 2 AD2 gradually increases from 0 to the locomotive power of the contact wire OCS12. When the locomotive leaves the transition zone Z12, the current of the contact wire OCS12 becomes 0. Before the locomotive enters the transition zone Z11, the controller MC continues to control the operation of the aforementioned AC-DC converter. While maintaining a constant output power, the AC port of AC-DC converter 2 AD2 gradually outputs the same voltage, frequency, and phase angle as the contact wire OCS11 through phase shifting. When the locomotive enters the transition zone Z11 from the right, the controller MC controls the aforementioned AC-DC converter to stop, and the locomotive is powered by the contact wire OCS11.

[0087] Preferably, the status of the uplink neutral segment N1 and the downlink neutral segment N2 is monitored by a fault detection device to determine whether they are in a normal state or a fault state.

[0088] Preferably, the controller MC calculates the power of the overhead contact line OCS11 locomotive and the power of the overhead contact line OCS21 locomotive using the input data from voltage transformer PT1, current transformer CT1, and current transformer CT2, respectively; the controller MC calculates the power of the overhead contact line OCS12 locomotive and the power of the overhead contact line OCS22 locomotive using the input data from voltage transformer PT2, current transformer CT3, and current transformer CT4, respectively.

[0089] Preferably, the controller MC detects the train position, train direction, and track occupancy status through a train position identifier.

[0090] Beneficial effects

[0091] Compared with the prior art, the beneficial effects of the present invention are:

[0092] I. The combined electrified railway flexible automatic phase-crossing device of this invention can be installed in both traction substations and sectioning substations. The system boasts powerful functions, flexible operation, and facilitates the combination and expansion of AC / DC converters. It is technically reliable and easy to implement. It achieves maximum combined functionality with a minimal number of AC / DC converters, enabling locomotive power supply, control, and switching in the neutral section, resulting in low investment costs. It is applicable to both double-track and single-track electrified railways, allowing locomotives to automatically cross phases without power interruption even when the contact network and the flexible phase-crossing device are under different operating conditions and states. It also possesses negative sequence management functions and power accommodation functions for both traction networks. All operating modes and their transitions do not require operation of feeder switches, thus not affecting the system's service life and ensuring high reliability. This combined electrified railway flexible automatic phase-crossing device belongs to the field of automatic phase-crossing on the ground in electrified railways and can be used in areas such as uninterrupted automatic phase-crossing of electrified railway trains, flexible power supply for electrified railways, flexible phase-crossing, and virtual in-phase power supply.

[0093] (1) A topology is proposed whereby the power supplies on both sides share a DC bus with n AC-DC converters (at least one AC-DC converter AD1, at least one AC-DC converter AD2, at least one AC-DC converter AD3, and at least one AC-DC converter AD4). This facilitates the combination of AC-DC converters into DC-AC converters to achieve power supply, control, and switching for the locomotive in the neutral section, and also facilitates expansion. By connecting the AC-DC converters AD1 and AD4 on the left and right power supply sides through the same DC bus, this topology also has the functions of power quality management and power sharing between the two traction networks.

[0094] (2) The AC-DC-AC combination form with shared power supply on the left and right sides and separate power supply on the neutral section achieves the maximum combination function with the fewest AC-DC converters, which can reduce the cost of the device and overcome the shortcomings of the existing technology that set AC-DC converters on the uplink and downlink power supply arms respectively, resulting in high investment costs.

[0095] (3) The AC-DC converter AD1 connected to the left U-phase power supply and the AC-DC converter AD4 connected to the right V-phase power supply are mutually redundant. When the AC-DC converter on one power supply side fails, it can supply power to the up and down locomotives through the AC-DC converter on the other power supply side, so as not to affect the normal operation of the locomotives in the neutral section and improve the reliability of the system.

[0096] (4) The measurement, switching, adjustment and control of the equipment are realized through the measuring and control device, so as to avoid the system life problem caused by the switching of the existing flexible phase divider.

[0097] II. The control method for the flexible automatic phase crossing of locomotives on double-track electrified railways of the present invention improves the complex contact wire closing process in the prior art, simplifies the control and adjustment process, and enables locomotives to pass through the neutral section safely and conveniently, under the premise of ensuring that the locomotive automatically crosses the phase without interrupting power and avoiding arcing problems caused by overvoltage, overcurrent and pantograph-catenary current disconnection.

[0098] Third, the control method of "V-stop reverse operation" for double-track electrified railway locomotives of the present invention can effectively solve the control problem of automatic phase transition without power failure when the upward neutral section N1 or the downward neutral section N2 fails. The upward neutral section N1 and the downward neutral section N2 serve as backups for each other. When one of the upward or downward neutral sections fails, the locomotive can be powered by the other neutral section through the "V-stop reverse operation" mode of the contact network, so that the locomotive can safely and automatically transition without power failure, thereby not affecting the normal operation of the locomotive and improving the reliability of the system. Attached Figure Description

[0099] The accompanying drawings are provided to further illustrate the embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention.

[0100] Figure 1 A schematic diagram of a combined flexible automatic phase-crossing device for electrified railways provided by the present invention.

[0101] Figure 2 This is a schematic diagram of the structure used to control the present invention using a measuring and controlling device.

[0102] Figure 3(a) is a schematic diagram of the flexible automatic phase transition of the uphill locomotive under normal operating conditions in the neutral section.

[0103] Figure 3(b) is a schematic diagram of the flexible automatic phase transition of the locomotive in the downlink direction under normal operating conditions in the neutral section.

[0104] Figure 4(a) shows a schematic diagram of the upward locomotive using the "V-stop and reverse" method for flexible automatic phase crossing during an upward neutral section fault.

[0105] Figure 4(b) is a schematic diagram of the structure of the locomotive using the "V-stop and reverse" method for flexible automatic phase crossing when there is a fault in the neutral section of the upward movement.

[0106] Figure 5 The terminal diagram of the combined electrified railway flexible automatic phase-crossing device provided by this invention includes the following reference numerals: U—left traction network phase, V—right traction network phase, BL—left AC bus, BR—right AC bus, KL—left AC bus normally closed switch, KR—right AC bus normally closed switch, DB—DC bus, AD1, AD2, AD3, AD4—AC converters, N1, N2—upward neutral section, downward neutral section, OCS11—left upward contact network, OCS12—right upward contact network. The overhead contact system consists of: OCS21—left-side down-going contact system, OCS22—right-side down-going contact system, Z11—transition zone near the left-side up-going contact system, Z12—transition zone near the right-side up-going contact system, Z21—transition zone near the left-side down-going contact system, Z22—transition zone near the right-side down-going contact system, CT1, CT2, CT3, CT4—current transformers, PT1, PT2—voltage transformers, F1, F2, F3, F4—feeders, K1, K2, K3, K4—switches. Detailed Implementation

[0107] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Specific Implementation Method 1

[0109] The first objective of this invention is to provide a combined flexible automatic phase-crossing device for single-track / double-track electrified railways and its double-track traction power supply system. This system can be installed in either traction substations or sectioning stations. It boasts powerful functions, flexible operation, and facilitates the combination and expansion of AC / DC converters. It is technically reliable and easy to implement. It achieves maximum combined functionality with a minimal number of AC / DC converters, enabling locomotive power supply, control, and switching in the neutral section, while maintaining low investment costs. It is applicable to both double-track and single-track electrified railways, allowing locomotives to automatically cross phases without power interruption even when the contact network and flexible phase-crossing device are in different operating conditions and states. It also features negative sequence mitigation and power accommodating capabilities between the two traction networks. All operating modes and transitions do not require operation of feeder switches, thus not affecting system lifespan and ensuring high reliability. This invention effectively solves the problems of limited applicability, fixed operation, low reliability, and limited expansion capabilities of existing flexible phase-crossing devices for both up and down tracks, which cannot meet the needs of locomotive operation under various conditions, as well as the system lifespan issues caused by switch switching.

[0110] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0111] like Figure 1 As shown in the diagram, this invention provides a structural schematic of a combined double-track electrified railway flexible automatic phase-crossing device, including an upward neutral section N1, a downward neutral section N2, and a DC bus DB. The device is characterized by further including at least one AC-DC converter AD1, at least one AC-DC converter AD2, at least one AC-DC converter AD3, and at least one AC-DC converter AD4. The DC ports of the AC-DC converters AD1, AD2, AD3, and AD4 are all connected to the same DC bus DB. Specifically, one terminal of the AC port of AC-DC converter AD1 is connected to the left U-phase AC bus BL, and the other terminal is grounded; one terminal of the AC port of AC-DC converter AD2 is connected to the upward neutral section N1, and the other terminal is grounded; one terminal of the AC port of AC-DC converter AD3 is connected to the downward neutral section N2, and the other terminal is grounded; one terminal of the AC port of AC-DC converter AD4 is connected to the right V-phase AC bus BR, and the other terminal is grounded.

[0112] First, Figure 1This diagram illustrates a topology where power supplies on both sides share a DC bus with n AC-DC converters (at least one AC-DC converter AD1, at least one AC-DC converter AD2, at least one AC-DC converter AD3, and at least one AC-DC converter AD4). This topology provides two power sources for the neutral section of the electrified railway: one from the left-side U-phase AC bus BL, and the other from the right-side V-phase AC bus BR. Simultaneously, the DC ports of all n AC-DC converters are connected to the same DC bus. This topology enables the AC-DC converters connected to the AC bus (hereinafter referred to as power-side AC-DC converters) to share a DC bus with the AC-DC converters connected to the up and down neutral sections. The neutral section AC-DC converter (hereinafter referred to as the neutral section AC-DC converter) is combined to supply power to the locomotives in the up and down neutral sections respectively. This allows the neutral section AC-DC converter AD2 to combine with at least one of the power supply-side AC-DC converters AD1 and AD4 to form a DC-AC converter to supply power to the up neutral section N1. Similarly, the neutral section AC-DC converter AD3 can combine with at least one of the power supply-side AC-DC converters AD1 and AD4 to form a DC-AC converter to supply power to the down neutral section N2. These multiple combinations allow the locomotive to be powered by the left U-phase, the right V-phase, or both power supplies simultaneously when passing through the neutral section, providing flexible operation. Furthermore, this flexible automatic phase-crossing device is applicable to both double-track electrified railways and single-track electrified railways.

[0113] Table 1 below shows the power supply and AC / DC converters used to power locomotives in the neutral sections N1 and N2, depending on whether locomotives are passing through. As can be seen from Table 1, when a locomotive passes through the neutral section N1, the locomotive can be powered by a combination of the left-side U-phase AC bus power supply and AC / DC converters AD1+AD2; alternatively, it can be powered by the right-side V-phase AC bus power supply and AC / DC converters AD4+AD2; or it can be powered by a combination of both left and right U-phase and V-phase AC bus power supplies and AC / DC converters AD1+AD4+AD2. Similarly, when a locomotive passes through the neutral section N2, or when locomotives pass through both the neutral sections N1 and N2 simultaneously, the corresponding power supply and AC / DC converters can be selected according to Table 1.

[0114] Table 1 shows the power supply and AC / DC converter combinations for the neutral section locomotive.

[0115]

[0116] second, Figure 1This demonstrates that the power source for the AC-DC converters on both power supply sides is directly taken from the AC bus, rather than having separate AC-DC converters on the up and down power supply arms on the left and right sides. This allows both power supply AC-DC converters on the left and right power supply sides to supply power to the up and down neutral sections. In other words, the up and down neutral section AC-DC converters can share the power supply AC-DC converters on both power supply sides. This AC-DC-AC combination form, which uses a shared power supply side and separate neutral section power supply, achieves maximum combined functionality with the fewest AC-DC converters, reducing equipment costs and overcoming the shortcomings of existing technologies that require separate AC-DC converters on the up and down power supply arms, resulting in high investment costs.

[0117] third, Figure 1 The AC-DC converter AD1, which connects to the left U-phase power supply, and the AC-DC converter AD4, which connects to the right V-phase power supply, can serve as backups for each other. When the AC-DC converter on one power supply side fails, power can be supplied to the up and down locomotives through the AC-DC converter on the other power supply side, thus not affecting the normal operation of the locomotives in the neutral section and improving the reliability of the system.

[0118] Table 2 below shows the power supply and AC / DC converters that supply power to the locomotives in the neutral section when a certain power supply side AC / DC converter fails. As can be seen from Table 2, when the right-side V-phase AC / DC converter AD4 fails, power is supplied to the locomotives in the up and / or down neutral sections via the left-side U-phase AC bus BL and AC / DC converter AD1 combined with the neutral section AC / DC converters. Specifically, when only the up neutral section N1 has locomotives passing through, power is supplied via the left-side U-phase AC bus BL and AC / DC converters AD1+A. The D2 combination supplies power to the locomotives in the upward neutral section N1. When only the locomotives in the downward neutral section N2 pass through, the left-side U-phase AC bus BL power supply and the AC-DC converter AD1+AD3 combination supply power to the locomotives in the downward neutral section N2 are used. When locomotives pass through both the upward and downward neutral sections N1 and N2, the left-side U-phase AC bus BL power supply and the AC-DC converter AD1+AD2+AD3 combination supply power to both locomotives in the upward and downward neutral sections N1 and N2 are used. Similarly, when the left-side U-phase AC-DC converter AD1 fails, the corresponding power supply and the corresponding AC-DC converter can be used according to Table 2.

[0119] Table 2 shows the power supply and AC / DC converter combination for the neutral section locomotives when a certain power supply side AC / DC converter fails.

[0120]

[0121] fourth, Figure 1The demonstration showed that the uplink neutral section N1 and the downlink neutral section N2 can also serve as backups for each other. When one of the uplink or downlink neutral sections fails, the locomotive can be powered by the other neutral section through the "V-stop reverse" operation mode of the overhead contact line. This allows the locomotive to safely and automatically pass through the phase transition without interrupting power, thus not affecting the normal operation of the locomotive and improving the reliability of the system.

[0122] Table 3 below shows the power supply and AC / DC converters that supply power to the locomotives in the neutral section when one of the upward or downward neutral sections fails. As can be seen from Table 3, when the downward neutral section N2 fails, both the upward and downward locomotives are powered by the upward neutral section N1. When the upward or downward locomotive enters the upward neutral section N1, it can be powered by the left U-phase AC bus power supply combined with AC / DC converters AD1+AD2, or by the right V-phase AC bus power supply combined with AC / DC converters AD4+AD2, or by the combined power supply of the left and right U-phase + V-phase AC buses combined with AC / DC converters AD1+AD4+AD2. Similarly, when the upward neutral section N1 fails, both the upward and downward locomotives are powered by the downward neutral section N2. The corresponding power supply and the corresponding AC / DC converter can be selected according to Table 3.

[0123] Table 3 shows the power supply and AC / DC converter combination for the locomotive in the neutral section when either the up or down neutral section is faulty.

[0124]

[0125] Fifth, by connecting the AC-DC converters AD1 and AD4 on the left and right power supply sides through the same DC bus DB, this topology also has the functions of power quality management and power sharing between the two traction networks.

[0126] Furthermore, one of each of the AC-DC converters AD1, AD2, AD3, and AD4 is provided. This achieves maximum combined functionality with the fewest possible AC-DC converters, further reducing system operating costs.

[0127] Furthermore, the n AC-DC converters also include a neutral section backup AC-DC converter. The backup AC-DC converter is put into operation when the neutral section AC-DC converter AD2 or AD3 fails, ensuring that the locomotive automatically transitions through the phase without power interruption, further improving the reliability of the system.

[0128] Furthermore, all AC-DC converters have the same structure and capacity, which facilitates development, backup, and operation and maintenance.

[0129] like Figure 2As shown, the present invention also includes a measurement and control unit (MC). The input terminal of the MC is connected to the measurement terminal of the detection equipment, and the output terminal of the MC is connected to the control terminals of n AC-DC converters. The MC is mainly used to receive signals and data from the detection equipment, and to realize the transfer of electrical energy from the power supply arm to the neutral section and the energy transfer between the two power supply arms by controlling the power output of the AC-DC converters, thus enabling the train to automatically pass through the phase without power interruption. When no train passes through the neutral section, the power quality management function of the two power supply arms and the power accommodation function of the traction networks on both sides are realized by controlling the switching of the AC-DC converters on the power supply side. The measurement, switching, adjustment and control of the equipment are realized through the measurement and control unit, avoiding the system life problems caused by switching in the existing flexible phase-crossing technology.

[0130] Furthermore, the detection equipment includes a train position identifier, a current transformer, and a voltage transformer. The train position identifier includes multiple train position sensors and related power supply lines. The voltage transformers include voltage transformer PT1 and voltage transformer PT2. The current transformers include current transformer CT1, current transformer CT2, current transformer CT3, and current transformer CT4. The train position identifier mainly identifies the train's position within a section of the electrified railway track, detecting whether a train has arrived at a designated location, detecting the train's direction of travel, and whether the track detection section is occupied. It then generates a train section position signal from the processed signal status and transmits it to the controller MC. The voltage transformer PTn detects the AC bus voltage, and the current transformer CTn detects the power supply line current for system protection and measurement control. It also transmits the processed data to the controller MC.

[0131] Furthermore, the left-side uplink contact network OCS11 and the left-side downlink contact network OCS21 are connected to the left-side U-phase AC bus BL via feeders F1 and F2, respectively. The right-side uplink contact network OCS12 and the right-side downlink contact network OCS22 are connected to the right-side V-phase AC bus BR via feeders F3 and F4, respectively. Switches K1, K2, K3, and K4 are installed on feeders F1, F2, F3, and F4, respectively. Current is drawn from the power supply arm via feeder Fn, and the switching of switch Kn determines whether the corresponding power supply arm is connected. This structure can control the system to operate in single-line or double-line mode, further increasing the flexibility of the operation mode.

[0132] Furthermore, the first current transformer CT1 is connected in series to the contact network OCS11, which leads to the upward neutral section N1 and is near the connection point of feeder F1; the second current transformer CT2 is connected in series to the contact network OCS21, which leads to the downward neutral section N2 and is near the connection point of feeder F2; the third current transformer CT3 is connected in series to the contact network OCS12, which leads to the upward neutral section N1 and is near the connection point of feeder F3; the fourth current transformer CT4 is connected in series to the contact network OCS22, which leads to the downward neutral section N2 and is near the connection point of feeder F4; the first voltage transformer PT1 is connected to the left U-phase AC bus BL, and the second voltage transformer PT2 is connected to the right V-phase AC bus BR. This structure reduces the number of detection devices by setting up an AC bus and placing voltage transformers on it. The voltage transformer PTn is used to detect the AC bus voltage, overcoming the shortcomings of existing technologies that sequentially set voltage transformers on each power supply arm, resulting in redundant detection devices. The current transformer CTn is used to detect the current on the contact wire. The data measured by the voltage transformer and the current transformer are used by the control controller MC to ensure that the neutral section voltage does not change abruptly and that the current (power) when the locomotive leaves the contact wire is 0.

[0133] Furthermore, the left-side U-phase AC bus BL and the right-side V-phase AC bus BR are two buses in the traction substation or two buses in the sectioning station. The combined electrified railway flexible automatic phase-crossing device of the present invention can be installed in either the traction substation or the sectioning station. Correspondingly, the left and right AC buses can be two buses in the traction substation or two buses in the sectioning station, thus solving the technical problem of uninterrupted automatic phase-crossing for locomotives at the traction substation and sectioning station respectively.

[0134] Furthermore, the U phase and V phase are respectively taken from any two phases of A, B, and C of the three-phase power grid or any two phases of AB, BC, and CA, wherein the phase angle difference between the U phase and V phase is 120°, 60°, or 90°; or the U phase and V phase are taken from the same phase of A, B, and C of the three-phase power grid or the same phase of AB, BC, and CA, wherein the phase angle difference between the U phase and V phase is 0°. When the AC busbars on the left and right sides are the two busbars of the traction substation, the U phase and V phase are respectively taken from any two phases of A, B, and C of the three-phase power grid or any two phases of AB, BC, and CA. The phase angle difference between the U phase and V phase is 120°, 60°, or 90° to match the voltage on both sides of the traction substation. When the AC busbars on the left and right sides are the two busbars of the sectioning substation, the U phase and V phase are taken from the same phase of A, B, and C of the three-phase power grid or the same phase of AB, BC, and CA. The phase angle difference between the U phase and V phase is 0° to match the voltage on both sides of the sectioning substation.

[0135] Furthermore, double-track electrified railways are equipped with crossovers, allowing upward-bound locomotives to travel from the upward track to the downward track, and vice versa, performing a "V" stop and reverse movement. This structure further ensures the smooth operation of locomotives in the event of a catenary failure on the double-track electrified railway.

[0136] Furthermore, the DC bus DB is either a high-voltage DC bus or a low-voltage DC bus.

[0137] Furthermore, each of the n AC-DC converters is equipped with a reactor or a matching transformer.

[0138] Furthermore, each of the n AC-DC converters is equipped with a matching transformer on its AC side; wherein, one winding of the matching transformer MT1 of AC-DC converter AD1 is connected to the AC side of AC-DC converter AD1, and the other winding serves as the AC port of AC-DC converter AD1, with one terminal connected to the left U-phase AC bus BL and the other terminal grounded; one winding of the matching transformer MT2 of AC-DC converter AD2 is connected to the AC side of AC-DC converter AD2, and the other winding serves as the AC port of AC-DC converter AD2, with one terminal connected to the upstream... The neutral section N1 is connected, and the other terminal is grounded; one side winding of the matching transformer MT3 of the AC-DC converter AD3 is connected to the AC side of the AC-DC converter AD3, and the other side winding serves as the AC port of the AC-DC converter AD3, with one terminal connected to the downlink neutral section N2 and the other terminal grounded; one side winding of the matching transformer MT4 of the AC-DC converter AD4 is connected to the AC port of the AC-DC converter AD4, and the other side winding serves as the AC port of the AC-DC converter AD4, with one terminal connected to the right-side V-phase AC bus BR and the other terminal grounded. Specific Implementation Method Two

[0140] The second objective of this invention is to provide a control method for the flexible automatic phase-crossing of locomotives on double-track electrified railways. This method improves upon the complex contact wire closing process in existing technologies, simplifying the control and adjustment process while ensuring uninterrupted automatic phase-crossing and avoiding arcing problems caused by overvoltage, overcurrent, and pantograph-catenary current interruption. This allows the locomotive to pass safely and conveniently through the neutral section. Furthermore, this control method also possesses the beneficial effects of the aforementioned combined flexible automatic phase-crossing device for electrified railways.

[0141] Figure 3(a) is a schematic diagram of the flexible automatic phase transition of the upward locomotive under normal operating conditions in the neutral section, and Figure 3(b) is a schematic diagram of the flexible automatic phase transition of the downward locomotive under normal operating conditions in the neutral section. The arrows in the figures indicate the direction of locomotive travel. The control method will be further described below with reference to the accompanying drawings and specific embodiments.

[0142] A control method for the flexible automatic phase-crossing device of a double-track electrified railway locomotive, based on the above-mentioned combined flexible automatic phase-crossing device, wherein the upward neutral section N1 and the downward neutral section N2 operate normally. The upward neutral section N1 includes a transition zone Z11 near the left upward contact line OCS11 and a transition zone Z12 near the right upward contact line OCS12. The downward neutral section N2 includes a transition zone Z21 near the left downward contact line OCS21 and a transition zone Z22 near the right downward contact line OCS22. The locomotive is powered only by the right upward contact line OCS12 in the transition zone Z12, and only by the left downward contact line OCS21 in the transition zone Z21. The method includes the following steps:

[0143] (1) When the uphill locomotive is about to enter the transition zone Z11 from the left, the controller MC controls at least one of the AC-DC converters AD2, AD1, and AD4 to operate, so that the AC port output of AC converter AD2 has the same U-phase voltage as the left-side uphill contact network OCS11, with the same magnitude, frequency, and phase angle; when the uphill locomotive enters the transition zone Z11 from the left, the controller MC continues to control the operating AC-DC converters, so that the power output of the AC port of AC converter AD2 gradually increases from 0 to the locomotive power of the left-side uphill contact network OCS11. When the locomotive leaves transition zone Z11, the current in the left-side uplink contact network OCS11 becomes 0. Before the uplink locomotive enters transition zone Z12, the controller MC continues to control the operation of the AC-DC converter, maintaining the output power while gradually shifting the phase voltage of the AC-DC converter AD2 AC port to the same V-phase voltage as the right-side uplink contact network OCS12, with the same magnitude, frequency, and phase angle. When the uplink locomotive enters transition zone Z12 from the left, the controller MC controls the operation of the AC-DC converter to stop, and the locomotive is powered by the right-side uplink contact network OCS12.

[0144] (2) When the locomotive is about to enter the transition zone Z22 from the right, the controller MC controls at least one of the AC-DC converters AD3, AD1, and AD4 to operate, so that the AC port output of AC converter AD3 has the same V-phase voltage as the right-side down-line contact network OCS22, with the same magnitude, frequency, and phase angle; when the locomotive enters the transition zone Z22 from the right, the controller MC continues to control the operating AC-DC converters, so that the power output of the AC port of AC converter AD3 gradually increases from 0 to the locomotive power of the right-side down-line contact network OCS22. When the locomotive leaves transition zone Z22, the current in the right-side downline contact network OCS22 becomes 0. Before the downline locomotive enters transition zone Z21, the controller MC continues to control the operating AC-DC converter. While maintaining a constant output power, the AC port of the AC-DC converter AD3 gradually outputs the same U-phase voltage as the left-side downline contact network OCS21 through phase shifting, with the same magnitude, frequency, and phase angle. When the downline locomotive enters transition zone Z21 from the right, the controller MC controls the operating AC-DC converter to stop, and the locomotive is powered by the left-side downline contact network OCS21.

[0145] Furthermore, double-track electrified railways are equipped with crossovers, allowing up-line locomotives to travel from the up line to the down line, and down-line locomotives to travel from the down line to the up line, performing a "V" stop and reverse movement.

[0146] Furthermore, the status of the uplink neutral segment N1 and the downlink neutral segment N2 is monitored by a fault detection device to determine whether they are in a normal state or a fault state.

[0147] Furthermore, the controller MC calculates the locomotive power of the left-side up-line contact network OCS11 and the left-side down-line contact network OCS21 respectively using the input data from voltage transformer PT1, current transformer CT1, and current transformer CT2; the controller MC calculates the locomotive power of the right-side up-line contact network OCS12 and the right-side down-line contact network OCS22 respectively using the input data from voltage transformer PT2, current transformer CT3, and current transformer CT4.

[0148] Furthermore, the controller MC detects the train position, train direction, and track occupancy status through the train position identifier. Specific Implementation Method 3

[0150] The third objective of this invention is to provide a control method for "V-stop reverse operation" of locomotives on double-track electrified railways. This method effectively solves the problem of controlling the locomotive to automatically cross phases without power failure when either the upward neutral section N1 or the downward neutral section N2 fails. The upward neutral section N1 and the downward neutral section N2 serve as backups for each other. When one of the upward or downward neutral sections fails, the locomotive can be powered by the other neutral section through the "V-stop reverse operation" mode of the overhead contact system, enabling the locomotive to safely and automatically cross phases without power failure, thus not affecting the normal operation of the locomotive and improving the reliability of the system.

[0151] Figure 4(a) shows a schematic diagram of the upward locomotive using the "V-stop reverse travel" flexible automatic phase crossing method when there is a fault in the upward neutral section. Figure 4(b) shows a schematic diagram of the downward locomotive using the "V-stop reverse travel" flexible automatic phase crossing method when there is a fault in the upward neutral section. The arrows in the figures indicate the locomotive's direction of travel. The "V-stop reverse travel" control method will be further described below with reference to the accompanying drawings and specific implementation methods.

[0152] A control method for "V-stop and reverse operation" of locomotives on double-track electrified railways based on the aforementioned combined flexible automatic phase-crossing device, wherein when a fault occurs in the neutral section N1 of the up-line or the neutral section N2 of the down-line, the locomotive uses the "V-stop and reverse operation" method to bypass the faulty section, including the following steps:

[0153] (1) When the upward neutral section N1 fails, the locomotive enters the left downward contact line OCS21 from the left upward contact line OCS11 before entering the upward neutral section N1. The control device MC is adjusted so that the locomotive can enter the downward neutral section N2 normally. The control device MC is adjusted so that the locomotive can exit the downward neutral section N2. After the locomotive exits the downward neutral section N2, it enters the right upward contact line OCS12 from the right downward contact line OCS22. The locomotive is powered by the right upward contact line OCS12.

[0154] (2) When the downlink neutral section N2 fails, the locomotive enters the right-side uplink contact line OCS12 from the right-side downlink contact line OCS22 before entering the downlink neutral section N2. The control device MC is adjusted to allow the locomotive to enter the uplink neutral section N1 normally. The control device MC is then adjusted to allow the locomotive to exit the uplink neutral section N1. After the locomotive exits the uplink neutral section N1, it enters the left-side downlink contact line OCS21 from the left-side uplink contact line OCS11. The locomotive is powered by the left-side downlink contact line OCS21.

[0155] Furthermore, the uplink neutral section N1 includes a transition zone Z11 near the left-side uplink contact line OCS11 and a transition zone Z12 near the right-side uplink contact line OCS12. The downlink neutral section N2 includes a transition zone Z21 near the left-side downlink contact line OCS21 and a transition zone Z22 near the right-side downlink contact line OCS22. In the transition zone Z11, the locomotive is powered only by the contact line OCS11, and in the transition zone Z22, the locomotive is powered only by the contact line OCS22.

[0156] Further, the step (1) of "adjusting the controller MC to allow the locomotive to normally enter the downlink neutral section N2, and continuing to adjust the controller MC to allow the locomotive to exit the downlink neutral section N2" includes: when the locomotive is about to enter the transition zone Z21 from the left, the controller MC controls at least one of the AC-DC converter AD3 and AC-DC converters AD1 and AD4 to operate, so that the AC port output of AC converter AD3 has the same U-phase voltage as the left downlink contact network OCS21, with the same magnitude, frequency, and phase angle; when the locomotive enters the transition zone Z21 from the left, the controller MC continues to control the operation of the aforementioned AC-DC converters, so that AC-DC converter AD3 outputs the same U-phase voltage as the left downlink contact network OCS21, with the same magnitude, frequency, and phase angle; when the locomotive enters the transition zone Z21 from the left, the controller MC continues to control the operation of the aforementioned AC-DC converters, so that AC-DC converter AD3... The power output from the AC port 3 gradually increases from 0 to the locomotive power of the left-side down-line contact network OCS21. When the locomotive leaves the transition zone Z21, the current of the left-side down-line contact network OCS21 becomes 0. Before the locomotive enters the transition zone Z22, the controller MC continues to control the operation of the AC-DC converter. While maintaining the output power, the AC port AD3 of the AC-DC converter gradually outputs the same V-phase voltage as the right-side down-line contact network OCS22 through phase shifting, with the same magnitude, frequency, and phase angle. When the locomotive enters the transition zone Z22 from the left, the controller MC controls the operation of the AC-DC converter to stop, and the locomotive is powered by the right-side down-line contact network OCS22.

[0157] Further, step (2) of "adjusting the controller MC to allow the locomotive to normally enter the upward neutral section N1, and continuing to adjust the controller MC to allow the locomotive to exit the upward neutral section N1" includes: when the locomotive is about to enter the transition zone Z12 from the right, the controller MC controls at least one of the AC-DC converter AD2 and AC-DC converters AD1 and AD4 to operate, so that the AC port output of AC converter AD2 has the same V-phase voltage as the right-side upward contact network OCS12, with the same magnitude, frequency, and phase angle; when the locomotive enters the transition zone Z12 from the right, the controller MC continues to control the operation of the aforementioned AC-DC converters, so that AC-DC converter AD2 outputs the same V-phase voltage as the right-side upward contact network OCS12, with the same magnitude, frequency, and phase angle; when the locomotive enters the transition zone Z12 from the right, the controller MC continues to control the operation of the aforementioned AC-DC converters, so that AC-DC converter AD2... 2. The power output from the AC port gradually increases from 0 to the locomotive power of the right-side uplink contact network OCS12. When the locomotive leaves the transition zone Z12, the current of the right-side uplink contact network OCS12 becomes 0. Before the locomotive enters the transition zone Z11, the controller MC continues to control the operation of the AC-DC converter. While maintaining the output power, the AC port of the AC-DC converter AD2 gradually outputs the same U-phase voltage as the left-side uplink contact network OCS11 through phase shifting, with the same magnitude, frequency, and phase angle. When the locomotive enters the transition zone Z11 from the right, the controller MC controls the operation of the AC-DC converter to stop, and the locomotive is powered by the left-side uplink contact network OCS11.

[0158] Furthermore, double-track electrified railways are equipped with crossovers, allowing up-line locomotives to travel from the up line to the down line, and down-line locomotives to travel from the down line to the up line, performing a "V" stop and reverse movement.

[0159] Furthermore, the status of the uplink neutral segment N1 and the downlink neutral segment N2 is monitored by a fault detection device to determine whether they are in a normal state or a fault state.

[0160] Furthermore, the controller MC calculates the locomotive power of the left-side up-line contact network OCS11 and the left-side down-line contact network OCS21 respectively using the input data from voltage transformer PT1, current transformer CT1, and current transformer CT2; the controller MC calculates the locomotive power of the right-side up-line contact network OCS12 and the right-side down-line contact network OCS22 respectively using the input data from voltage transformer PT2, current transformer CT3, and current transformer CT4.

[0161] Furthermore, the controller MC detects the train position, train direction, and track occupancy status through the train position identifier.

[0162] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. Persons skilled in the art will appreciate that improvements and modifications may be made without departing from the spirit and scope of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A combined flexible automatic phase-separation device, characterized in that, It includes a DC bus DB, an AC bus BL, an AC bus BR, a monitoring and control unit MC, at least one AC-DC converter AD1, at least one AC-DC converter AD2, at least one AC-DC converter AD3, and at least one AC-DC converter AD4, wherein, One end of the AC port of the AC-DC converter AD1 is connected to the AC bus BL, and the other end is grounded; the AC bus BL is provided with two lead-out terminals, which serve as the input / output terminals A11 and A12 of the combined flexible automatic phase-crossing device, respectively. One end of the AC port of the AC-DC converter AD2 serves as the input / output terminal A2 of the combined flexible automatic phase-crossing device for connection with the upstream neutral section N1, and the other end is grounded; One end of the AC port of the AC-DC converter AD3 serves as the input / output terminal A3 of the combined flexible automatic phase-crossing device for connection to the downlink neutral section N2, and the other end is grounded; One end of the AC port of the AC-DC converter AD4 is connected to the AC bus BR, and the other end is grounded; the AC bus BR is provided with two lead-out terminals, which serve as the input / output terminals A41 and A42 of the combined flexible automatic phase-crossing device, respectively. The DC ports of AC-DC converters AD1, AD2, AD3, and AD4 are all connected to the DC bus DB. The input terminal of the controller MC is connected to the measurement terminal of the detection equipment, and the output terminal of the controller MC is connected to the control terminal of AC-DC converters AD1, AD2, AD3, and AD4.

2. The combined flexible automatic phase-separating device according to claim 1, characterized in that, The two leads of the AC bus BL are connected to feeders F1 and F2 respectively. A switch K1 is connected in series on feeder F1 and a switch K2 is connected in series on feeder F2.

3. The combined flexible automatic phase-separating device according to claim 2, characterized in that, A switch KL is connected in series on the AC bus BL between feeders F1 and F2.

4. The combined flexible automatic phase-crossing device according to claim 1, characterized in that, The two leads of the AC bus BR are connected to feeders F3 and F4 respectively. A switch K3 is connected in series on feeder F3 and a switch K4 is connected in series on feeder F4.

5. A combined flexible automatic phase-separating device according to claim 4, characterized in that, A switch KR is connected in series on the AC bus BR between feeders F3 and F4.

6. The flexible automatic phase-splitting device according to claim 1, characterized in that, One AC-DC converter AD1, one AC-DC converter AD2, one AC-DC converter AD3, and one AC-DC converter AD4 are each provided.

7. A combined flexible automatic phase-crossing device according to any one of claims 1-6, characterized in that, It also includes a backup AC-DC converter B, which, under the control of the controller MC, can serve as a backup for the AC-DC converters AD1, AD2, AD3, or AD4.

8. A combined flexible automatic phase-crossing device according to any one of claims 1-6, characterized in that, AC-DC converters AD1, AD2, AD3, and AD4 have the same structure and equal capacity.

9. A combined flexible automatic phase-crossing device according to any one of claims 1-6, characterized in that, The detection equipment includes: Multiple train position identifiers for identifying train positions; Multiple current transformers used to detect the current in the overhead contact line; Multiple voltage transformers for detecting AC bus voltage; The measuring terminals of the train position identifier, current transformer, and voltage transformer are all connected to the input terminal of the controller MC.

10. A combined flexible automatic phase-crossing device according to any one of claims 1-6, characterized in that, The DC bus DB is either a high-voltage DC bus or a low-voltage DC bus.

11. A combined flexible automatic phase-crossing device according to any one of claims 1-6, characterized in that, AC-DC converters AD1, AD2, AD3, and AD4 are all equipped with reactors or matching transformers.

12. A combined flexible automatic phase-crossing device according to any one of claims 1-6, characterized in that, The flexible automatic phase-separation device is installed in the electrical separation unit of the traction substation or in the electrical separation unit of the section substation.

13. A combined flexible automatic phase-crossing device according to any one of claims 1-6, characterized in that, The AC busbars BL and BR are the two traction buses of the traction substation or the two buses of the section substation.

14. A combined flexible automatic phase-crossing device according to any one of claims 1-6, wherein the AC bus BL and AC bus BR are respectively taken from any two phases A, B, and C of a three-phase power grid or any two phases AB, BC, and CA, wherein, The phase angle difference between the AC bus BL and the AC bus BR is 120°, 60° or 90°; or the AC bus BL and the AC bus BR are taken from the same phase of A, B, C or the same phase of AB, BC, CA corresponding to the three-phase power grid, wherein the phase angle difference between the AC bus BL and the AC bus BR is 0°.

15. A double-track traction power supply system, characterized in that, The device includes the combined flexible automatic phase-crossing device according to any one of claims 1-14, wherein the input / output terminals A11, A12, A41 and A42 of the combined flexible automatic phase-crossing device are respectively connected to the left upward contact network OCS11, the left downward contact network OCS21, the right upward contact network OCS12 and the right downward contact network OCS22.

16. A double-track traction power supply system according to claim 15, characterized in that, The detection equipment includes: Current transformer CT1 is connected in series with the left-side up-line contact network OCS11 and is close to the connection point of feeder F1; Current transformer CT2 is connected in series with the left-side down contact network OCS21 and is located near the feeder F2 connection point; Current transformer CT3 is connected in series with the right-side up-line contact network OCS12 and is located near the feeder F3 connection point; Current transformer CT4 is connected in series with the right-side down contact network OCS22 and is located near the feeder F4 connection point; Voltage transformer PT1 connected in parallel to AC bus BL; Voltage transformer PT2 is connected in parallel to AC bus BR.

17. A double-track traction power supply system according to claim 15 or 16, characterized in that, Double-track electrified railways are equipped with crossovers, allowing up-line locomotives to transition from the up track to the down track, and down-line locomotives to transition from the down track to the up track, performing a "V" stop and reverse movement.

18. A flexible automatic phase-crossing control method for a double-track electrified railway based on the double-track traction power supply system according to any one of claims 15-17, characterized in that, The control method includes an automatic phase-crossing control mode for uphill locomotives and an automatic phase-crossing control mode for downhill locomotives.

19. The control method according to claim 18, characterized in that, The upward neutral section N1 includes a transition zone Z11 near the left-side upward contact line OCS11 and a transition zone Z12 near the right-side upward contact line OCS12. In the automatic phase-crossing control mode for the upward locomotive, the control method includes: First, obtain the position information of the uplink locomotive and determine whether the uplink locomotive is about to enter the transition area Z11. If so, control at least one of the AC-DC converters AD1 and AD4 to work together with the AC-DC converter AD2 so that the AC port output of the AC converter AD2 is the same voltage as the left uplink contact network OCS11. Second, obtain the location information of the uplink locomotive and determine whether the uplink locomotive has entered the transition area Z11. If so, continue to control the operation of the AC-DC converter that is currently running, so that the power output of the AC port of the AC-DC converter AD2 gradually increases from 0 to the locomotive power of the left uplink contact network OCS11.

3. Obtain the position information of the uplink locomotive and determine whether the uplink locomotive is leaving the transition zone Z11. If so, when the uplink locomotive leaves the transition zone Z11, control the current obtained by the uplink neutral section N1 from the left-side uplink contact network OCS11 to be 0. After leaving the transition zone Z11, continue to control the operation of the AC-DC converter that is currently running. While maintaining the output power unchanged, make the AC port of the AC-DC converter AD2 gradually output the same voltage as the right-side upward contact network OCS12 through phase shifting. Fourth, obtain the location information of the uplink locomotive and determine whether the uplink locomotive has entered the transition zone Z12. If so, control the above-mentioned AC-DC converter that is currently in operation to stop, and the uplink locomotive will be powered by the right-side uplink contact network OCS12.

20. The control method according to claim 18, characterized in that, The downlink neutral section N2 includes a transition zone Z21 near the left downlink contact network OCS21 and a transition zone Z22 near the right downlink contact network OCS22. In the downlink locomotive automatic phase-crossing control mode, the control method includes: First, obtain the location information of the downlink locomotive and determine whether the downlink locomotive is about to enter the transition area Z22. If so, control at least one of the AC-DC converters AD1 and AD4 to work together with the AC-DC converter AD3 so that the AC port output of the AC converter AD3 is the same voltage as the right downlink contact network OCS22. Second, obtain the location information of the downlink locomotive and determine whether the downlink locomotive has entered the transition area Z22. If so, continue to control the operation of the AC-DC converter that is currently running, so that the power output of the AC port of the AC-DC converter AD3 gradually increases from 0 to the locomotive power of the right downlink contact network OCS22.

3. Obtain the location information of the downlink locomotive and determine whether the downlink locomotive is leaving the transition area Z22. If so, when the downlink locomotive leaves the transition area Z22, control the current obtained by the downlink neutral section N2 from the right downlink contact network OCS22 to be 0. After leaving the transition zone Z22, continue to control the operation of the AC-DC converter that is currently in operation. While maintaining the output power unchanged, make the AC port of the AC-DC converter AD3 gradually output the same voltage as the left-downward contact network OCS21 through phase shifting. Fourth, obtain the location information of the uplink locomotive and determine whether the downlink locomotive has entered the transition zone Z21. If so, control the above-mentioned AC-DC converter in operation to stop, and the downlink locomotive will be powered by the left downlink contact network OCS21.

21. The control method according to any one of claims 18-20, characterized in that, It also includes a power merging mode, in which the control method includes: Determine whether there is an up-line or down-line locomotive about to undergo power phase switching. If not, control AC-DC converters AD1 and AD4 to work together to perform power switching control on the left up-line contact network OCS11 and the right up-line contact network OCS12, or to perform power switching control on the right down-line contact network OCS22 and the left down-line contact network OCS21.

22. The control method according to any one of claims 18-20, characterized in that, The measuring and control device MC calculates the locomotive power of the left-side up-line contact network OCS11 and the left-side down-line contact network OCS21 respectively using the input data from voltage transformer PT1 and current transformers CT1 and CT2; the measuring and control device MC calculates the locomotive power of the right-side up-line contact network OCS12 and the right-side down-line contact network OCS22 respectively using the input data from voltage transformer PT2 and current transformers CT3 and CT4.

23. The control method according to any one of claims 18-20, wherein the controller MC detects the train position, train direction of travel, and track detection section occupancy status through a train position identifier.

24. A method for controlling the "V-stop / reverse movement" of a double-track electrified railway locomotive based on the double-track traction power supply system according to any one of claims 15-17, characterized in that, When a fault occurs in the upward neutral section N1 or the downward neutral section N2, the train will use a "V-stop and reverse" method to bypass the faulty section, including the following steps: (1) When the upward neutral section N1 fails, the locomotive enters the left downward contact line OCS21 from the left upward contact line OCS11 before entering the upward neutral section N1. The control device MC is adjusted so that the locomotive can enter the downward neutral section N2 normally. The control device MC is adjusted so that the locomotive can exit the downward neutral section N2. After the locomotive exits the downward neutral section N2, it enters the right upward contact line OCS12 from the right downward contact line OCS22. The locomotive is powered by the right upward contact line OCS12. (2) When the downlink neutral section N2 fails, the locomotive enters the right-side uplink contact line OCS12 from the right-side downlink contact line OCS22 before entering the downlink neutral section N2. The control device MC is adjusted to allow the locomotive to enter the uplink neutral section N1 normally. The control device MC is then adjusted to allow the locomotive to exit the uplink neutral section N1. After the locomotive exits the uplink neutral section N1, it enters the left-side downlink contact line OCS21 from the left-side uplink contact line OCS11. The locomotive is powered by the left-side downlink contact line OCS21.

25. The control method according to claim 24, characterized in that, The uplink neutral section N1 includes a transition zone Z11 near the left-side uplink contact network OCS11 and a transition zone Z12 near the right-side uplink contact network OCS12. The downlink neutral section N2 includes a transition zone Z21 near the left-side downlink contact network OCS21 and a transition zone Z22 near the right-side downlink contact network OCS22.

26. The control method according to claim 25, characterized in that, Step (1) "Adjusting the controller MC to allow the locomotive to normally enter the downlink neutral section N2, and continuing to adjust the controller MC to allow the locomotive to exit the downlink neutral section N2" includes: When the locomotive is about to enter the transition zone Z21 from the left, the controller MC controls at least one of the AC-DC converters AD1 and AD4 to work in conjunction with the AC-DC converter AD3, so that the AC port output of the three AC-DC converters AD3 has the same voltage, the same magnitude, the same frequency, and the same phase angle as the contact network OCS21; When the locomotive enters the transition zone Z21 from the left, the controller MC continues to control the aforementioned operating AC-DC converters to work, so that the AC-DC converters AD3 output the same voltage, the same frequency, and the same phase angle as the contact network OCS21; The power output from the AD3 AC port of the converter gradually increases from 0 to the locomotive power of the contact wire OCS21. When the locomotive leaves the transition zone Z21, the current of the contact wire OCS21 becomes 0. Before the locomotive enters the transition zone Z22, the controller MC continues to control the operation of the AC-DC converter. While maintaining the output power, the AC port of the AD3 AC converter gradually outputs the same voltage, frequency, and phase angle as the contact wire OCS22 through phase shifting. When the locomotive enters the transition zone Z22 from the left, the controller MC controls the AC-DC converter to stop, and the locomotive is powered by the contact wire OCS22.

27. The control method according to claim 25, characterized in that, Step (2) "Adjusting the controller MC to allow the locomotive to normally enter the upward neutral section N1, and continuing to adjust the controller MC to allow the locomotive to exit the upward neutral section N1" includes the following steps: When the locomotive is about to enter the transition zone Z12 from the right, the controller MC controls at least one of the AC-DC converters AD1 and AD4 to work in conjunction with the AC-DC converter AD2, so that the AC port output of the AC converter AD2 has the same voltage, magnitude, frequency, and phase angle as the contact network OCS12; when the locomotive enters the transition zone Z12 from the right, the controller MC continues to control the aforementioned operating AC-DC converters to work, so that the AC-DC converters... The power output from the AC port of converter two (AD2) gradually increases from 0 to the locomotive power of the contact wire OCS12. When the locomotive leaves the transition zone Z12, the current of the contact wire OCS12 becomes 0. Before the locomotive enters the transition zone Z11, the controller MC continues to control the operation of the AC-DC converter. While maintaining a constant output power, the AC port of AC-DC converter two (AD2) gradually outputs the same voltage, frequency, and phase angle as the contact wire OCS11 through phase shifting. When the locomotive enters the transition zone Z11 from the right, the controller MC controls the operation of the AC-DC converter to stop, and the locomotive is powered by the contact wire OCS11.

28. The control method according to any one of claims 24-27, wherein the state of the uplink neutral segment N1 and the downlink neutral segment N2 is monitored by a fault detection device to determine whether they are in a normal state or a fault state.

29. The control method according to any one of claims 24-27, wherein the measuring and controlling device MC calculates the power of the overhead contact line OCS11 locomotive and the power of the overhead contact line OCS21 locomotive respectively using the input data of voltage transformer PT1, current transformer CT1, and current transformer CT2; and the measuring and controlling device MC calculates the power of the overhead contact line OCS12 locomotive and the power of the overhead contact line OCS22 locomotive respectively using the input data of voltage transformer PT2, current transformer CT3, and current transformer CT4.

30. The control method according to any one of claims 24-27, wherein the controller MC detects the train position, train direction of travel, and track detection section occupancy status through a train position identifier.

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