Metro traction substation regenerative power feedback device cooperative control method

Abstract

This invention discloses a collaborative control method for regenerative energy feedback devices in metro traction substations, relating to the field of metro traction power supply process control technology. It acquires the DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, energy feedback power, and energy feedback device operating status of each traction substation within the collaborative section, generating station records. It generates feedback demand records based on changes in DC traction network voltage, energy feedback power, and operating status. It generates load records based on bus voltage margin, incoming line voltage increase, and feedback rise. It matches feedback demands with load status, determines feedback stations, limited-feed stations, and exit stations, and issues corresponding instructions. It corrects the station role for the next control cycle based on voltage changes after instruction execution. This ensures that multi-station feedback control matches the 35kV bus load status, reducing collaborative interference caused by independent feedback from a single station.

Description

Technical Field

[0001] This invention relates to the field of subway traction power supply process control technology, and more specifically, to a method for coordinated control of regenerative energy feedback devices in subway traction substations. Background Technology

[0002] Regenerative energy is generated during subway train braking, and this energy is typically fed back to the AC side via a regenerative energy feedback device in the traction power supply system. Existing regenerative energy feedback devices are mostly controlled by a single traction substation, starting, stopping, and adjusting based on changes in the DC traction network voltage, DC side current, or device feedback power. While some systems incorporate data exchange between adjacent substations, control decisions still primarily revolve around the local operating status or fixed power distribution relationships of each station. In subway traction power supply scenarios, the regenerative energy generated during train braking is short-lived and transient, and it propagates along the traction network between adjacent substations. If a substation detects an increase in DC traction network voltage, it only reflects the presence of regenerative energy input on its side, not directly whether the 35kV bus still has the voltage margin to receive the feedback energy. Simultaneously, external power supply voltage fluctuations can cause the 35kV bus voltage to be in different load states. If adjacent substations initiate feedback or adjust feedback power based on local voltage changes, it can easily lead to inconsistent feedback timing, mutually restrictive power adjustment directions, and delayed status assessments of adjacent stations. Especially when there are delays, asynchronous states, or short-term interruptions in inter-station communication, the status of adjacent stations obtained by the control node may deviate from the actual status on site, further distorting the basis for judging feedback actions in multi-station collaborative control.

[0003] It is known that existing single-station threshold control, fixed power allocation, or general inter-station communication coordination methods have the problem that local feedback judgment is difficult to accurately match the overall load-bearing status of the 35kV bus when multiple traction substations jointly participate in regenerative energy feedback. Summary of the Invention

[0004] To address the problem of inaccurate matching of local feedback judgment with the overall load-bearing status of the 35kV bus, this invention provides a collaborative control method for regenerative energy feedback devices in metro traction substations. By acquiring the DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, energy feedback power, and energy feedback device operating status of each traction substation within the collaborative section, the feedback requirements and 35kV bus load-bearing status of each traction substation are determined. When the feedback requirements and 35kV bus load-bearing status do not match, a mismatch record is generated. Based on the mismatch record, inter-station connection relationships, and the load-bearing status of each traction substation, feedback stations, limited-feeding stations, and exit stations are determined, thereby outputting corresponding feedback power commands, limited-feeding commands, or exit commands to each energy feedback device.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for coordinated control of regenerative power feedback devices in subway traction substations includes: S1. Obtain the DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, power supply power, and power supply device operating status of each traction substation in the coordinated section, and generate station records according to the traction substation identification and acquisition time. S2. Based on the DC traction network voltage changes, power feeder changes, and power feeder device operating status recorded at the stations, determine the feedback requirements of each traction substation, whether feedback is required, maintained, or not required, and generate feedback requirement records. S3. Based on the changes in 35kV bus voltage and 35kV incoming line voltage in the station records, as well as the corresponding increase in 35kV bus voltage when the power feeder increases, determine the 35kV bus load status of each traction substation that allows, restricts, or prohibits feedback, and generate a load record. S4. Match the feedback demand record with the load record according to the traction substation identifier, identify the feedback demand as a traction substation that needs to provide feedback or maintain feedback and whose 35kV bus load status is restricted or prohibited from providing feedback, and generate a mismatch record. S5. Based on the mismatch records, the feedback requirements of each traction substation, the 35kV bus load status of each traction substation, and the inter-station connection relationship between each traction substation, determine the feedback station, the limited feeder station, and the exit station, and generate role records. S6. Based on the role record, output feedback power command to the energy feeder device of the feedback station, output limiting feeder command to the energy feeder device of the limiting feeder station, output exit command to the energy feeder device of the exit station, and collect the DC traction network voltage change and 35kV bus voltage change after the control command is executed.

[0006] Furthermore, S1 includes: S1.1. Based on the adjacent relationship of the DC traction network and the 35kV side ring network relationship between traction substations, candidate sites for participating in coordinated control are selected from traction substations equipped with regenerative power feedback devices to form a candidate site set. S1.2 Compare the inter-site connection relationships between each candidate site in the candidate site set, and retain the candidate sites that have a DC side adjacent relationship or a 35kV side ring network relationship with at least one other candidate site as cooperative sites, thus obtaining the cooperative site set; S1.3 According to the station order and inter-station connection relationship of each collaborative station in the collaborative station set, each collaborative station is assigned to the same collaborative section, and the traction substation corresponding to each collaborative station in the collaborative section is taken as the collection object of the station record.

[0007] Furthermore, S1 also includes: S1.4. The regenerative power feedback devices configured in each traction substation within the coordinated section are used as energy feeder devices. The DC traction network voltage is read from the DC side acquisition interface of each traction substation within the coordinated section, the 35kV bus voltage and 35kV incoming line voltage are read from the 35kV side acquisition interface, and the energy feeder power and energy feeder device operating status are read from the energy feeder device to obtain the original data of the station. S1.5. Collect the original data of the stations according to the identification of the traction substation, and align the DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, power supply power and power supply device operation status under the same traction substation identification with the time of collection to obtain the station data at the same time. S1.6 Write the station data at the same time into the data item corresponding to the traction substation identifier and the acquisition time to form a station record containing DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, power feeder power and power feeder device operating status.

[0008] Furthermore, S2 includes: S2.1. Retrieve the station records corresponding to the same traction substation identifier at the continuous acquisition time, and perform differential processing on the DC traction network voltage and power feed at the continuous acquisition time to obtain the DC traction network voltage change and power feed change. S2.2. Screen each traction substation for feedback eligibility based on the operating status of the energy feeder. Traction substations whose energy feeder operating status is faulty or out of service are marked as traction substations that are not eligible for feedback. Traction substations whose energy feeder operating status does not indicate fault or out of service are designated as stations to be judged. S2.3. Make corresponding judgments on the DC traction network voltage changes and energy feed power changes of the stations to be judged. Determine the stations to be judged where the DC traction network voltage changes are positive and the energy feed power changes are negative as traction substations that need feedback. Determine the stations to be judged where the energy feed power is in the output state and the DC traction network voltage changes are negative as traction substations that maintain feedback. Determine the stations to be judged where the traction substations do not have the qualification for feedback and the stations to be judged where the DC traction network voltage changes are negative and the energy feed power is not in the output state as traction substations that do not need feedback. Generate feedback demand records according to the traction substation identification.

[0009] Furthermore, S3 includes: S3.1. Retrieve the 35kV bus voltage and 35kV incoming line voltage from the records of the corresponding stations of the same traction substation. Use the difference between the upper limit of the allowed operation of the 35kV bus and the 35kV bus voltage as the basic margin. When the 35kV incoming line voltage increases, deduct the increase in 35kV incoming line voltage from the basic margin to obtain the bus voltage margin. S3.2 Select the data collection period when the power feeder increases under the same traction substation identification, take the increase in 35kV bus voltage during the data collection period as the feedback rise amount, and write the feedback rise amount and the power feeder increase amount into the feedback rise record accordingly. S3.3. Compare the bus voltage margin with the feedback rise amount. When the bus voltage margin is greater than or equal to the feedback rise amount, determine the 35kV bus load status as permissible feedback. When the bus voltage margin is greater than zero and less than the feedback rise amount, determine the 35kV bus load status as restricted feedback. When the bus voltage margin is less than or equal to zero, determine the 35kV bus load status as prohibited feedback. Generate a load record according to the traction substation identification.

[0010] Furthermore, S4 includes: S4.1 Using the traction substation identifier and acquisition time as matching fields, the feedback demand records and load records within the same control cycle are paired to obtain the site matching records; S4.2 In the site matching record, traction substations with feedback requirements of "required feedback" or "keep feedback" and 35kV bus load status of "restricted feedback" are marked as limited feeder mismatched sites, and traction substations with feedback requirements of "required feedback" or "keep feedback" and 35kV bus load status of "prohibited feedback" are marked as exited mismatched sites. S4.3 Write the feeder mismatch site, exit mismatch site, corresponding feedback requirement type, 35kV bus load status and acquisition time into the same record to form a mismatch record.

[0011] Furthermore, S5 includes: S5.1 Read the feed-limited mismatched stations and exit mismatched stations in the mismatched records, and set the feed-limited mismatched stations as feed-limited pending stations and the exit mismatched stations as exit pending stations. S5.2 When the feedback requirement of each traction substation is to require feedback or maintain feedback and the 35kV bus load status is to allow feedback, the corresponding traction substation shall be included in the feedback site set. When the traction substation belongs to the limited feeder undetermined site, it shall be determined as a limited feeder site. When the traction substation belongs to the exit undetermined site, it shall be determined as an exit site. S5.3 Write the feedback site set, limited feedback sites, exited sites, and corresponding feedback requirements, 35kV bus load status, and site source into the role record.

[0012] Furthermore, S5 also includes: S5.4. The feedback requirements corresponding to the limited feeder station and the exit station are identified as the requirements to be accepted. From the set of feedback stations, traction substations that have inter-station connection with the limited feeder station or the exit station and whose 35kV bus load status allows feedback are selected to obtain the candidate stations to be accepted. S5.5 Compare the inter-station connection relationships between the candidate sites and the feed-limited or withdrawn sites, and determine the candidate sites with direct inter-station connection relationships as the main feed-in sites, and determine the candidate sites connected through other traction substations as auxiliary feed-in sites. S5.6 Write the main feedback site, auxiliary feedback site, limited feedback site, and exit site into the role record respectively, and retain the pending needs undertaken by the main feedback site or auxiliary feedback site in the role record.

[0013] Furthermore, S6 includes: S6.1 Read the main feedback station, auxiliary feedback station, limited feedback station and exit station in the role record, and retrieve the feedback requirements, 35kV bus load status and power of each station to form an instruction object record; S6.2 According to the instruction object record, output the main feedback power instruction to the energy feeder device of the main feedback station, output the auxiliary feedback power instruction to the energy feeder device of the auxiliary feedback station, output the limiting energy feeder instruction to the energy feeder device of the limiting feeder station to reduce the energy feeder power or maintain the limited energy feeder power, and output the exit instruction to the energy feeder device of the exit station to stop feeding back to the 35kV bus. S6.3 After the feedback power command, feed-limiting command and exit command are issued, the DC traction network voltage, 35kV bus voltage and feed-in power of the corresponding station are collected, and the station data after control is formed based on the time of command issuance.

[0014] Furthermore, S6 also includes: S6.4 Compare the control data of the stations with the station records before the command was issued to obtain the changes in DC traction network voltage, 35kV bus voltage and power feeder, and form a command response record. S6.5. Compare the command response record and mismatch record. If the DC traction network voltage continues to rise and the 35kV bus voltage continues to rise after the control command is executed at the same traction substation, mark the corresponding traction substation as a reverse response station and generate a reverse response record. S6.6 When executing S5 in the next control cycle, the reverse response record is used as the role correction input; when the reverse response station meets the feedback station determination conditions, the reverse response station is placed after other feedback stations for selection; when the reverse response station meets the limited feedback station or exit station determination conditions, the reverse response station is preferentially determined as a limited feedback station or exit station.

[0015] Beneficial effects:

[0016] 1. By matching feedback requirements with the 35kV bus load status at each site, local feedback judgment is incorporated into the bus margin constraint, making multi-site feedback decisions more aligned with the 35kV side load capacity. 2. By deducting the foundation margin from the 35kV incoming line voltage rise and combining it with the feedback rise to classify the load-bearing status, the risk of bus voltage rise caused by continued feedback can be relatively reduced when the external power fluctuates. 3. Based on the mismatch records, determine the limited feedback sites and exit sites, and then select the main feedback sites and auxiliary feedback sites from the allowed feedback sites, so that the needs to be received can be transferred in an orderly manner between adjacent sites; 4. By distinguishing between primary and secondary feedback sites through inter-site connections, pending requests are prioritized to be handled by directly associated sites, which can reduce the uncertainty of the collaborative path caused by the participation of remote sites; 5. Record the changes in DC traction network voltage and 35kV bus voltage after the command is executed in reverse response and feed them back to the next control cycle so that the station role allocation can be corrected according to the actual response. 6. By uniformly collecting data at specific times to form site records and continuously saving them according to the control cycle, feedback requirements, carrying status, and command responses have a consistent data standard, reducing judgment errors caused by asynchronous data from multiple sources. Attached Figure Description

[0017] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0018] 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.

[0019] Reference Figure 1This invention relates to a collaborative control method for regenerative energy feedback devices in metro traction substations. It is applicable to scenarios where multiple adjacent traction substations are equipped with regenerative energy feedback devices, and where collaborative control of the feedback actions at each station is required when regenerative energy is generated during train braking. In this embodiment, the regenerative energy feedback device is referred to as the energy feeder device in the following description. The energy feeder device is a device installed in the traction substation to feed back the regenerative energy generated during train braking to the 35kV AC side via the traction power supply system. The energy feeder power is the power value fed back to the 35kV side by the energy feeder device at the time of data collection. The operating status of the energy feeder device includes running, limited feeder, outage, and fault. The control cycle is the execution interval corresponding to a single station record collection, feedback demand judgment, load status judgment, role record generation, control command issuance, and response collection. Inter-station connections include DC side adjacent relationships, 35kV side ring network relationships, direct inter-station connections, and connections via other traction substations. The 35kV side ring network relationship is determined by whether the traction substation is connected to the same 35kV power supply ring network, the same 35kV ring network segmentation, or the existence of a 35kV side ring network. The voltage linkage relationship is determined; during execution, the coordination section is first determined based on the adjacent relationships of the DC traction network and the 35kV side ring network relationship, and the DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, power feedback, and power feedback device operating status of each traction substation within the coordination section are collected to form a site record with a unified time caliber; then, the feedback requirements of each traction substation are determined based on the changes in DC traction network voltage, power feedback power, and power feedback device operating status, and combined with the changes in 35kV bus voltage, 35kV incoming line voltage, and... The impact of increased power feedback on the rise of the 35kV bus voltage determines the 35kV bus load status. When the feedback demand does not match the 35kV bus load status, a mismatch record is generated. Based on the mismatch record, inter-station connection relationships, and the load status of each traction substation, feedback stations, limited feeder stations, and exit stations are determined, and feedback power commands, limited feeder commands, or exit commands are output to the corresponding power feedback devices. Finally, the station role allocation for the next control cycle is corrected based on the changes in DC traction network voltage and 35kV bus voltage after the control commands are executed.

[0020] S1. The collaborative control node first reads the list of traction substations, the list of regenerative energy feedback devices, the DC traction network connection relationship, and the 35kV side ring network relationship in the traction power supply system. The DC traction network adjacency relationship is determined by the adjacent traction sections, the DC feeder connection range, or the DC traction network segment connection relationship. When a traction substation has been configured with a regenerative energy feedback device and has a DC traction network adjacency relationship or a 35kV side ring network relationship with other traction substations, the corresponding traction substation is written into the candidate site set. The candidate site records the traction substation identifier, the regenerative energy feedback device configuration status, the DC side connection information, and the 35kV side connection information in the candidate site set. The collaborative control node takes any candidate site in the candidate site set as the current candidate site and compares the connection relationship between the current candidate site and other candidate sites in the candidate site set. If the current candidate site has a DC-side adjacency relationship with any other candidate site, or a 35kV-side ring network relationship with any other candidate site, the current candidate site is retained as a collaborative site. If a candidate site is equipped with a regenerative power feedback device, but does not have a DC-side adjacency relationship with other candidate sites and does not have a 35kV-side ring network relationship, it is not added to the collaborative site set. The collaborative control nodes sort the collaborative sites in the collaborative site set according to the subway line direction, the arrangement order of the traction substations in the line, the DC traction network connection path, and the 35kV side ring network connection path. Collaborative sites that can be continuously connected through DC side adjacency, or collaborative sites that are not directly adjacent on the DC side but have a 35kV side ring network relationship and voltage linkage relationship, are assigned to the same collaborative section. The collaborative section limits the range of traction substations that participate in site record collection and collaborative control judgment within the same control cycle. The collaborative control node establishes a data acquisition item for each traction substation within the collaborative section. The data acquisition item includes the traction substation identifier, the identifier of the collaborative section to which it belongs, the station sequence, the DC side acquisition interface address, the 35kV side acquisition interface address, and the energy feeder communication address. The traction substation identifier is used to associate the DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, energy feeder power, and energy feeder operating status of the same traction substation. The identifier of the collaborative section to which it belongs is used to distinguish different collaborative control ranges. The station sequence is used to subsequently determine the direct inter-station connection relationship or the relationship connected through other traction substations. The collaborative control node reads the DC traction network voltage from the DC side acquisition interface of each traction substation within the collaborative section. The DC side acquisition interface is set at the DC bus, DC feeder, or traction network voltage acquisition unit of the traction substation. When the same traction substation has multiple DC side acquisition points, the DC voltage value corresponding to the energy feeder access point is selected first, or the DC bus voltage value that can represent the change of traction network voltage within the same acquisition period is selected. The read DC traction network voltage is associated with the traction substation identifier, acquisition time, and DC side acquisition interface address and saved. The collaborative control node reads the 35kV bus voltage and 35kV incoming line voltage from the 35kV side acquisition interface of each traction substation within the collaborative section; the 35kV bus voltage is read from the 35kV bus voltage acquisition unit of the traction substation, which is used to indicate the bus voltage status after the power feedback is sent back to the 35kV side; the 35kV incoming line voltage is read from the 35kV incoming line side voltage acquisition unit, which is used to indicate the change in the input voltage of the external power supply side; during acquisition, the 35kV bus voltage and 35kV incoming line voltage are associated and saved with the traction substation identifier, acquisition time, and 35kV side acquisition interface address, respectively; The collaborative control node reads the power feedback and operating status of the power feedback device through the communication interface of the power feedback device, the power feedback device controller, or the traction power supply monitoring system. The power feedback is the active power feedback output by the power feedback device to the 35kV side. The operating status of the power feedback device is determined by the operation flag, feed-limiting flag, exit flag, or fault flag sent by the power feedback device controller. After reading, the DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, power feedback, and operating status of the power feedback device corresponding to the same traction substation together constitute the original data of the site. The original data of the site retains the original acquisition time and data source interface of each data item. The collaborative control node uses the traction substation identifier as the aggregation field to write the original data from the DC side acquisition interface, the 35kV side acquisition interface, and the power feeder device into the data group corresponding to the same traction substation. When the arrival time of data from different interfaces differs, the original acquisition time carried by each data item is retained, and temporary aggregation is completed according to the traction substation identifier. The data group under the same traction substation identifier includes DC traction network voltage data items, 35kV bus voltage data items, 35kV incoming line voltage data items, power feeder power data items, and power feeder device operating status data items. The collaborative control node uses the acquisition time as a reference to align the DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, power supply capacity, and power supply device operating status under the same traction substation identification, thus obtaining data for the same station. The acquisition time adopts the unified acquisition time within the same control cycle, or the synchronous acquisition time determined by the collaborative control node. When data acquired by different interfaces within the same control cycle falls into the same acquisition window, it is classified as data for the same station. When there is a deviation between the acquisition time of a data item and the alignment reference, the acquisition value closest to the alignment reference is selected for alignment. When a data item is missing in the current acquisition window, the corresponding data item is marked as missing. The collaborative control node sets fields for traction substation identification, acquisition time, DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, power feeder, and power feeder device operating status in the site records, and writes the site data at the same moment into the corresponding fields respectively; the site records are continuously saved according to the control cycle, so that the same traction substation identification forms a time-arranged sequence of site records at different acquisition times; when the feedback requirement is determined later, the DC traction network voltage and power feeder at the consecutive acquisition times are read from the site record sequence; when the 35kV bus load status is determined later, the 35kV bus voltage, 35kV incoming line voltage, and power feeder are read from the site records. For example, within a certain section, traction substations A, B, and C are all equipped with regenerative power feedback devices. There are DC-side adjacency relationships between traction substations A and B, and between traction substations B and C, and the three are connected by a 35kV side ring network. The collaborative control node assigns traction substations A, B, and C to the same collaborative section, and reads their DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, power feedback, and power feedback device operating status, and then writes them into the station record according to the traction substation identification and the same data acquisition time.

[0021] S2. The collaborative control node uses the traction substation identifier as an index to read the station record at the current acquisition time and the station record at the previous acquisition time from the station record sequence. The current acquisition time and the previous acquisition time belong to the continuous control cycle of the same collaborative section. When there are multiple acquisition windows under the same traction substation identifier, the previous acquisition time that is adjacent to the current control cycle and has complete data items is selected as the comparison object. The read station records include DC traction network voltage, power feeder power, and power feeder device operating status. The collaborative control node subtracts the DC traction network voltage from the previous acquisition time from the current acquisition time to obtain the DC traction network voltage change corresponding to the same traction substation identifier; a difference greater than zero indicates that the DC traction network voltage has increased relative to the previous acquisition time in the current control cycle, and a difference less than or equal to zero indicates that the DC traction network voltage has not continued to increase in the current control cycle. The collaborative control node subtracts the energy feed power from the energy feed power at the previous acquisition time from the energy feed power at the current acquisition time to obtain the energy feed power change corresponding to the same traction substation identifier; a greater than zero energy feed power change indicates that the energy feed device has increased feedback output in the current control cycle, and a less than or equal to zero energy feed power change indicates that the energy feed device has not increased feedback output; the energy feed power being in the output state is determined by the energy feed power being greater than zero, the energy feed device being in the effective feedback output flag, or the feedback operation flag sent by the energy feed device controller; The collaborative control node reads the operating status of the energy feeder at the current acquisition time and maps the operating status of the energy feeder to operating, limited feeder, exit, and fault. The operating status indicates that the energy feeder has the conditions to receive feedback power commands normally. The limited feeder status indicates that the energy feeder can perform feedback within the limited power range. The exit status indicates that the energy feeder does not participate in the feedback output of the current control cycle. The fault status indicates that the energy feeder has protection lockout, communication abnormality, power module abnormality, or other states that prevent it from executing feedback commands. The collaborative control node marks traction substations whose energy feeder device is in a fault or out of operation as traction substations that are not eligible for feedback, and adds the corresponding traction substations to the list of sites that are not eligible for feedback; traction substations whose energy feeder device is in operation or limited are reserved as sites to be judged, and the DC traction network voltage change, energy feeder power change and current energy feeder power value corresponding to the sites to be judged are written into the data items to be judged. The collaborative control node uses the DC traction network voltage change and energy feed power change under the same traction substation identification as a set of judgment data to judge the feedback demand of the site to be judged; when the DC traction network voltage change of the site to be judged is positive and the energy feed power change is non-positive, it indicates that there is a voltage rise trend on the DC side and the energy feed device has not increased feedback output or the feedback output is insufficient, and the feedback demand type of the corresponding traction substation is written as feedback required. When the power feedback of the station under test is in the output state and the DC traction network voltage change is non-positive, it indicates that the current feedback output of the station under test corresponds to the DC side voltage suppression process, and the feedback demand type of the corresponding traction substation is written as "keep feedback". Traction substations that do not qualify for feedback are not the target of feedback power command execution in the current control cycle, and "no feedback required" is written in the feedback demand record. When the DC traction network voltage change of the station under test is non-positive and the power feedback is not in the output state, the feedback demand type of the corresponding traction substation is written as "no feedback required". The collaborative control node writes the feedback demand type, DC traction network voltage change, power feeder change, power feeder device operating status and acquisition time corresponding to each traction substation into the same record to form a feedback demand record. The feedback demand types include feedback required, feedback maintained, and feedback not required. Traction substations that require feedback enter the subsequent bus load status matching process, traction substations that maintain feedback continue to participate in the 35kV bus load status judgment, and traction substations that do not require feedback are not used as feedback output objects in the current control cycle. For example, within the same control cycle, if the DC traction network voltage of traction substation A increases compared to the previous acquisition time, and the power feed does not increase, the collaborative control node determines that the feedback demand of traction substation A needs to be fed back; if the power feed of traction substation B is already in the output state, and the DC traction network voltage does not continue to increase, the collaborative control node determines that the feedback demand of traction substation B needs to be maintained; if the power feed device of traction substation C is in the off-state, the collaborative control node determines that the feedback demand of traction substation C does not need to be fed back.

[0022] S3. The collaborative control node uses the traction substation identifier and the current acquisition time as indexes to read the 35kV bus voltage and 35kV incoming line voltage within the current control cycle from the station records. The 35kV bus voltage is the voltage value output by the 35kV bus side voltage acquisition unit of the corresponding traction substation, used to indicate the current voltage state of the bus after regenerated power is fed back to the AC side. The 35kV incoming line voltage is the voltage value output by the 35kV incoming line voltage acquisition unit of the corresponding traction substation, used to reflect changes in the input voltage of the external power supply side. The collaborative control node reads the upper limit of the 35kV busbar's permissible operation. This upper limit is derived from the traction power supply system's operating limits, the permissible voltage range of the 35kV busbar equipment, relay protection settings, dispatching operation limits, or the corresponding upper limit value in the project's operation and maintenance procedures. After obtaining the upper limit of the 35kV busbar's permissible operation, the node subtracts the current 35kV busbar voltage at the time of data acquisition from the upper limit to obtain the basic margin. A basic margin greater than zero indicates that there is still remaining voltage space between the current 35kV busbar voltage and the permissible operating limit; a basic margin less than or equal to zero indicates that the current 35kV busbar voltage has reached or exceeded the corresponding upper limit. The collaborative control node compares the 35kV incoming line voltage at the current acquisition time with the 35kV incoming line voltage at the previous acquisition time. When the 35kV incoming line voltage at the current acquisition time is higher than that at the previous acquisition time, the difference between the two is taken as the increase in 35kV incoming line voltage. When the 35kV incoming line voltage at the current acquisition time is less than or equal to that at the previous acquisition time, the increase in 35kV incoming line voltage is taken as zero. Then, the increase in 35kV incoming line voltage is subtracted from the base margin to obtain the bus voltage margin. The collaborative control node reads the power feed at consecutive acquisition times from the site record sequence corresponding to the same traction substation identifier. The continuous interval where the power feed at a later acquisition time is higher than that of the previous acquisition time is defined as the acquisition period for power feed increase. The acquisition period includes the start and end times of the power increase, and retains the corresponding 35kV bus voltage within that period. If no power feed increase acquisition period is formed in the current control cycle, the feedback rise record from the historical control cycle of the same traction substation is read. If there is no historical feedback rise record for the same traction substation, the feedback rise record corresponding to the traction substation with the same or similar 35kV bus load status and a complete power feed increase process within the same collaborative section is read as an initial reference. When no available feedback rise records exist within the same traction substation and the same coordinated section, the coordinated control node reads the initial feedback rise record formed during the commissioning phase. The initial feedback rise record is formed by the increase in energy feed power and the increase in 35kV bus voltage collected when the energy feeder outputs a small-power step feedback. If the bus voltage margin is greater than zero before the initial feedback rise record is formed, the current control cycle will process the 35kV bus load status of the corresponding traction substation according to the restricted feedback method. If the bus voltage margin is less than or equal to zero, the current control cycle will process the 35kV bus load status of the corresponding traction substation according to the prohibited feedback method. The feedback rise record will be updated after a subsequent effective energy feed power increase collection period. The collaborative control node reads the 35kV bus voltage at the start of the sampling period when the power feedback increases and the 35kV bus voltage at the end of the sampling period. It subtracts the 35kV bus voltage at the start of the sampling period from the 35kV bus voltage at the end of the sampling period to obtain the increase in 35kV bus voltage, and uses this increase as the feedback boost. When there are multiple sampling points within the sampling period, the maximum 35kV bus voltage within the sampling period is subtracted from the voltage value at the start of the sampling period to obtain the feedback boost corresponding to that sampling period. After determining the feedback lift amount, the collaborative control node simultaneously calculates the increase in power feed during the acquisition period. The increase in power feed is obtained by subtracting the power feed at the beginning of the acquisition period from the power feed at the end of the acquisition period. Subsequently, the traction substation identifier, acquisition period, power feed increase, feedback lift amount, 35kV bus voltage at the beginning of the acquisition period, 35kV bus voltage at the end of the acquisition period, and the corresponding 35kV incoming line voltage change are written into the feedback lift record. The collaborative control node compares the bus voltage margin corresponding to the same traction substation identifier with the feedback rise amount. The bus voltage margin has been calculated based on the current 35kV bus voltage and the 35kV incoming line voltage rise amount, and the feedback rise amount has been obtained from the feedback rise records of the current control cycle, historical control cycle, or similar stations. The comparison process uses the same traction substation identifier or the reference record of the same collaborative section that has been explicitly selected. When the bus voltage margin is greater than or equal to the feedback rise, the collaborative control node writes the 35kV bus load status of the corresponding traction substation as "feedback allowed" and retains the bus voltage margin, feedback rise, and acquisition time used for judgment; when the bus voltage margin is greater than zero and less than the feedback rise, the collaborative control node writes the 35kV bus load status of the corresponding traction substation as "feedback restricted"; when the bus voltage margin is less than or equal to zero, the collaborative control node writes the 35kV bus load status of the corresponding traction substation as "feedback prohibited". The collaborative control node writes the traction substation identifier, acquisition time, 35kV bus voltage, 35kV incoming line voltage, foundation margin, 35kV incoming line voltage rise, bus voltage margin, feedback rise, and 35kV bus load status into the same load record. The load record is consistent with the feedback demand record according to the traction substation identifier, so that the feedback demand can be matched with the 35kV bus load status according to the same traction substation identifier in the future. For example, if the 35kV bus voltage of traction substation A still has a basic margin between its allowable operating limit and the 35kV bus voltage, and the resulting bus voltage margin after deducting the increase in 35kV incoming line voltage is greater than or equal to the feedback rise, the collaborative control node will determine the 35kV bus load status of traction substation A as allowable feedback; if the bus voltage margin of traction substation B is greater than zero but less than the feedback rise, the collaborative control node will determine the 35kV bus load status of traction substation B as restricted feedback; if the bus voltage margin of traction substation C is less than or equal to zero, the collaborative control node will determine the 35kV bus load status of traction substation C as prohibited feedback.

[0023] S4. The collaborative control node reads the feedback demand record and load record generated within the current control cycle. The feedback demand record includes the traction substation identifier, acquisition time, and feedback demand type. The load record includes the traction substation identifier, acquisition time, and 35kV bus load status. The collaborative control node uses the traction substation identifier as the first matching field and the acquisition time as the second matching field to merge the feedback demand record and load record corresponding to the same traction substation and the same acquisition time into the same site matching record. When there is a slight deviation between the acquisition time of the feedback demand record and the load record within the acquisition window, the acquisition time after time alignment within the same control cycle is used as the matching time. When a traction substation has only a feedback demand record or only a load record, the corresponding site matching record is marked as incomplete and will not participate in the identification of mismatched sites in this control cycle. The collaborative control node reads complete site matching records, first determining whether the feedback demand type is "feedback required" or "feedback to be maintained," and then determining whether the 35kV bus load status in the same site matching record is "feedback restricted." If both conditions are met, it indicates that the corresponding traction substation has a need to start or continue feedback within the current control cycle, but the 35kV bus only has limited load-bearing capacity and it is difficult to execute the power output according to the complete feedback demand. In this case, the corresponding traction substation identifier is written into the "feedback restricted mismatched site" field, and the feedback demand type, 35kV bus load status, bus voltage margin, feedback rise amount, and acquisition time are retained. The collaborative control node continues to judge the site matching records that are not marked as incomplete data; when the feedback demand type is "feedback required" or "feedback to be maintained", and the 35kV bus carrying status is "feedback prohibited", it means that the corresponding traction substation has a feedback demand on the DC side or has an existing feedback output that needs to be maintained, but the corresponding 35kV bus, after deducting the impact of the 35kV incoming voltage increase, no longer has the voltage space to continue to receive feedback power; in this case, the corresponding traction substation identifier is written into the exit mismatched site field, and the judgment basis for prohibiting feedback is retained; when the same traction substation meets both the restriction feedback and prohibition feedback judgment conditions in the same control cycle, the exit mismatched site corresponding to prohibition feedback is taken as the priority result; The collaborative control node establishes a mismatch record entry for the current control cycle and writes it into the feeder-limited mismatch site and exit mismatch site according to the traction substation identifier. Each mismatch record includes the traction substation identifier, acquisition time, feedback demand type, 35kV bus load status, mismatch type, corresponding control cycle identifier, and data source identifier. The mismatch type is written as feeder-limited mismatch or exit mismatch according to the identification result, and the data source identifier points to the corresponding feedback demand record and load record. For example, if the feedback requirement of traction substation A is "feedback required" and the 35kV bus load status is "feedback allowed," the collaborative control node will not write traction substation A into the mismatch record. If the feedback requirement of traction substation B is "feedback maintained" and the 35kV bus load status is "feedback restricted," the collaborative control node will mark traction substation B as a limited-feedback mismatch site. If the feedback requirement of traction substation C is "feedback required" and the 35kV bus load status is "feedback prohibited," the collaborative control node will mark traction substation C as an exited mismatch site and write the corresponding information of traction substations B and C into the mismatch record.

[0024] S5. The collaborative control node uses the current control cycle identifier as an index to read the mismatch type, traction substation identifier, acquisition time, feedback demand type, and 35kV bus load status from the mismatch record. When the mismatch type corresponds to feeder limiting mismatch, the corresponding traction substation identifier is extracted as the feeder limiting mismatch site. When the mismatch type corresponds to exit mismatch, the corresponding traction substation identifier is extracted as the exit mismatch site. When there are multiple mismatch records for the same traction substation in the same control cycle, the record with the latest acquisition time and complete data source is used as the basis for role determination in this control cycle. The collaborative control node writes the identification of the traction substation corresponding to the mismatched feeder-limited site into the feeder-limited undetermined site list, and simultaneously writes the corresponding feedback demand type, the 35kV bus load status of the restricted feedback, the bus voltage margin, and the feedback rise amount; the feeder-limited undetermined site indicates that the traction substation still has a need for feedback or to maintain feedback in the current control cycle, but the corresponding 35kV bus load status only supports restricted feedback. The collaborative control node writes the identifier of the traction substation corresponding to the exit from the mismatched site into the exit from the list of pending sites, and simultaneously writes the corresponding feedback demand type, the bearing status of the 35kV bus that is prohibited from feedback, the bus voltage margin and the acquisition time. Exit from the pending site means that the traction substation has a need to provide feedback or maintain feedback within the current control cycle, but the corresponding 35kV bus no longer has the voltage space to receive the feedback power. The collaborative control node reads the feedback demand records and load records of each traction substation within the current control cycle, and matches them with the traction substation identifier and the acquisition time. When the feedback demand of the same traction substation is either "required to provide feedback" or "remains to provide feedback", and the 35kV bus load status is "feedback allowed", the corresponding traction substation identifier is written into the feedback site set. When writing, the corresponding feedback demand type, power supply, bus voltage margin, feedback rise amount, and inter-site connection relationship are retained. The collaborative control node compares the traction substation identifier in the current control cycle with the list of feed-limited stations to be determined. If the traction substation identifier exists in the list of feed-limited stations to be determined, the station role of the traction substation is set as a feed-limited station. The feed-limited station subsequently receives feed-limited instructions to reduce the feed-in power or maintain the feed-in power. Feedback requests that the feed-limited station fails to fully execute enter the pending request processing process. The collaborative control node compares the traction substation identifier in the current control cycle with the list of exiting pending sites; if the traction substation identifier exists in the list of exiting pending sites, the site role of the traction substation is written as an exiting site; the exiting site subsequently receives an exit instruction to stop feeding back to the 35kV bus, and the feedback requirement corresponding to the exiting site is handed over as a pending requirement to an adjacent or associated site that has the conditions to allow feedback. The collaborative control node establishes role record entries for the current control cycle and writes them into feedback stations, limited feeder stations, and exit stations according to the traction substation identifier. Each role record includes the traction substation identifier, data acquisition time, station role, feedback demand type, 35kV bus load status, feeder power, station source, and control cycle identifier. The station source includes those determined by the load status that allows feedback, those determined by limited feeder mismatch stations, those determined by exit mismatch stations, and those determined by screening pending demand. The collaborative control node reads the feedback demand type in the feedback demand record of the limited feeder station and the exited station, and determines the demand to be accepted by the corresponding energy feeder power, energy feeder power change, DC traction network voltage change and 35kV bus load status. The demand to be accepted by the limited feeder station corresponds to the feedback demand that exceeds the limited energy feeder power range. The demand to be accepted by the exited station corresponds to the feedback demand that the exited station needs to feed back or maintain feedback in the current control cycle but cannot continue to be accepted by the 35kV bus of this station. The demand to be accepted is associated with the traction substation identifier of the limited feeder station or the exited station and saved. The collaborative control node takes the limited feeder site or the exit site as the demand source site, and reads the inter-site connection relationship and 35kV bus load status of each feedback site in the feedback site set one by one; when there is a DC side adjacent relationship, a 35kV side ring network relationship or a reachable connection path determined by the collaborative section topology between a certain feedback site and the demand source site, and the 35kV bus load status of the feedback site is allowed to feed back, the feedback site is written into the candidate site for receiving the task. The coordinated control node reads the inter-station connection relationship table within the coordinated section. The inter-station connection relationship table includes traction substation identification, station order, DC side adjacency relationship, 35kV side ring network relationship, and connection path. Taking the feed-limited station or the decommissioned station as the demand source station, it calculates the connection type between each candidate station and the demand source station. When the candidate station and the demand source station are directly adjacent or have a direct 35kV side ring network connection relationship, it is recorded as a direct inter-station connection relationship. When the candidate station and the demand source station need to pass through one or more intermediate traction substations to form a connection path, it is recorded as a connection through other traction substations. Both primary and secondary feedback sites are selected from the set of feedback sites, representing a further role division of feedback sites when undertaking receiving and receiving demands. The collaborative control node selects sites with direct inter-site connections to limited feeder sites or exiting sites from the candidate sites and writes the selection results as primary feedback sites. When there are multiple candidate sites with direct inter-site connections, one or more primary feedback sites are determined according to the rules of larger bus voltage margin, lower current feeder power, closer inter-site distance to the demand source site, or priority of adjacent site sequence. Primary feedback sites take priority in receiving primary feedback power commands and take priority in undertaking the demand to be undertaken by limited feeder sites or exiting sites. The collaborative control node selects sites from the candidate sites that have a connection path with the feed-limited or withdrawn sites but are not directly connected to each other, and writes the selection results as auxiliary feedback sites. When there are multiple auxiliary feedback sites, the participation order is determined according to the number of intermediate traction substations in the connection path, the bus voltage margin, the current feed-in power, and the order of the sites in the collaborative section. Auxiliary feedback sites participate in feedback acceptance when the main feedback site has insufficient capacity, insufficient number of main feedback sites, or multiple pending needs. The collaborative control node adds the main feedback station field, auxiliary feedback station field, limited feedback station field, and exit station field to the role record of the current control cycle, and writes the traction substation identifier corresponding to each type of station into the corresponding field; when there are multiple role judgment results for the same traction substation in the same control cycle, the role is confirmed according to the priority of exit station, limited feedback station, main feedback station, and auxiliary feedback station to avoid the same energy feeder receiving conflicting control commands at the same time. The collaborative control node writes the source site identifier, source site role, feedback demand type, corresponding energy feed power, DC traction network voltage change, 35kV bus load status, and the identifier of the main feedback site or auxiliary feedback site that will undertake the demand into the role record; when a demand to be undertaken is undertaken by multiple main feedback sites or auxiliary feedback sites, the undertaking relationship and participation order are written into the role record respectively. For example, if traction substation A has a feedback requirement and the 35kV busbar is in a feedback-allowed state, the collaborative control node will add traction substation A to the feedback site set; if traction substation B is a limited-feeding mismatch site, the collaborative control node will identify traction substation B as a limited-feeding site; if traction substation C is an exit mismatch site, the collaborative control node will identify traction substation C as an exit site; when traction substation A and traction substation B have a direct inter-station connection, the collaborative control node will identify traction substation A as the primary feedback site and write the relationship in the role record that traction substation A undertakes the needs to be undertaken by traction substation B.

[0025] S6. The collaborative control node uses the current control cycle identifier as an index to read the traction substation identifier, acquisition time, station role, station source, and pending demand relationship corresponding to various stations from the role record; the main feedback station takes priority in accepting the pending demand corresponding to the limited feeder station or the exit station; the auxiliary feedback station participates in feedback acceptance when the main feedback station's acceptance capacity is insufficient or there are multiple pending demands; the limited feeder station receives instructions to reduce the energy feeder power or maintain the limited energy feeder power; the exit station receives instructions to stop feeding back to the 35kV bus. Based on the traction substation identifier in the role record, the collaborative control node reads the feedback demand type, 35kV bus load status, and power feed at the same acquisition time from the feedback demand record, load record, and site record respectively; then it writes the traction substation identifier, site role, feedback demand type, 35kV bus load status, power feed, source of demand to be received, and control cycle identifier into the same instruction object record. The collaborative control node reads the traction substation identifier marked as the main feedback station in the instruction object record, and determines the main feedback power instruction based on the feedback requirements of the main feedback station itself, the corresponding needs to be received, the current energy feedback power, and the 35kV bus load status. The main feedback power instruction includes the target feedback power, the direction of power increase, the power adjustment range, and the instruction validity period. The adjustment range is constrained by the bus voltage margin of the main feedback station, the feedback rise amount, and the current energy feedback power, so that the energy feedback device of the main feedback station increases or maintains feedback output under the allowable feedback load status. When determining the main feedback power command, the collaborative control node reads the bus voltage margin and feedback rise record corresponding to the main feedback station, and calculates the additional feedback power that the main feedback station can add within the current bus voltage margin based on the correspondence between the increase in feedback power and the feedback rise amount in the feedback rise record. During the calculation, when the feedback rise amount is greater than zero, the ratio of the bus voltage margin to the feedback rise amount is used as the acceptable proportion, and the product of the increase in feedback power and the acceptable proportion is used as the additional feedback power calculated based on the bus voltage margin. When the power supply is less than or equal to zero, the rated power of the power supply device, the current operating limit of the power supply device, or the power limit value issued by the traction power supply monitoring system is read as the upper limit of the allowable power of the power supply device, and the difference between the upper limit of the allowable power of the power supply device and the current power supply is taken as the power supply that can be increased. The power increase used for the main feedback power command shall not exceed the smaller value between the power supply corresponding to the demand to be accepted and the power supply that can be increased. When the power supply corresponding to the demand to be accepted is greater than the power supply that can be increased, the remaining demand to be accepted shall be reserved for the auxiliary feedback station. The collaborative control node reads the traction substation identifier marked as an auxiliary feedback station from the instruction object record, and reads the source of the pending demand undertaken by the auxiliary feedback station, the current energy feed power, and the 35kV bus load status. The auxiliary feedback power instruction includes the auxiliary target feedback power, the auxiliary undertaking ratio, the power adjustment direction, and the instruction validity period. When the main feedback station has undertaken part of the pending demand but there is still remaining pending demand, the auxiliary feedback station receives the auxiliary feedback power instruction according to the undertaking relationship and participation order retained in the role record. The adjustment range of the auxiliary feedback power instruction is constrained by the bus voltage margin of the auxiliary feedback station, the feedback rise record, and the upper limit of the allowable power of the energy feed device. When determining the auxiliary feedback power command, the collaborative control node reads the remaining unaccepted demand from the main feedback station and calculates the additional energy feed power that the auxiliary feedback station can add based on the auxiliary feedback station's bus voltage margin, feedback rise records, and the upper limit of the allowable power of the energy feeder device. When the feedback rise is greater than zero, the ratio of the bus voltage margin to the feedback rise is used as the auxiliary acceptance ratio, and the product of the increase in energy feed power and the auxiliary acceptance ratio is used as the additional energy feed power that the auxiliary feedback station can add. When the feedback rise is less than or equal to zero, the difference between the upper limit of the allowable power of the energy feeder device and the current energy feed power is used as the additional energy feed power. When the remaining unaccepted demand is less than or equal to the additional energy feed power that the auxiliary feedback station can add, the auxiliary feedback station accepts all the remaining unaccepted demand. When the remaining unaccepted demand is greater than the additional energy feed power that the auxiliary feedback station can add, the auxiliary feedback station participates in accepting the demand according to the additional energy feed power, and the unaccepted portion is carried over to the next auxiliary feedback station or the next control cycle. The collaborative control node reads the identifier of the traction substation marked as a limited feeder station from the instruction object record, and reads the current feeder power, 35kV bus load status, bus voltage margin, and feedback rise amount corresponding to the limited feeder station. When the current feeder power of the limited feeder station is higher than the power range allowed by the limited load status, the limited feeder instruction is set to reduce the feeder power and the target limited feeder power or the power reduction amount is given. When the current feeder power of the limited feeder station is already within the limited range, the limited feeder instruction is set to maintain the limited feeder power. After the limited feeder instruction is issued, the feeder device of the limited feeder station will not continue to increase the feedback output in the current control cycle. The limited energy feed power range is determined based on the ratio between the bus voltage margin and the feedback rise at the limited feed station. The collaborative control node reads the current energy feed power, bus voltage margin, and feedback rise at the limited feed station. When the bus voltage margin is greater than zero and less than the feedback rise, the ratio of the bus voltage margin to the feedback rise is used as the limited feed ratio, and the product of the current energy feed power and the limited feed ratio is used as the target limited energy feed power. When the target limited energy feed power is lower than the minimum stable feedback power of the energy feed device, the limited feed command is adjusted to an exit command or the energy feed device is controlled to remain in standby mode. The collaborative control node reads the identifier of the traction substation marked as the exit station from the instruction object record, and reads the 35kV bus load status and current power feed of the exit station; when the 35kV bus load status of the exit station is prohibited from feedback, the node outputs an exit command to the power feed device of the exit station, causing the power feed device to stop outputting feedback power to the 35kV bus; the exit command includes status flags such as power reduced to zero, stopping feedback operation, maintaining standby state, or entering the current control cycle without participating in feedback. After the feedback power command, feed-limiting command, and exit command are issued, the collaborative control node uses the traction substation identifier in the command object record as the data acquisition object, reads the DC traction network voltage from the DC side acquisition interface of the corresponding traction substation, reads the 35kV bus voltage from the 35kV side acquisition interface, and reads the feed-in power from the feed-in device; during data acquisition, the command issuance time, acquisition time, station role, and command type are retained; The collaborative control node uses the command issuance time as the time reference for the formation of post-control data. After one control response cycle or one acquisition window following the command issuance, it writes the read DC traction network voltage, 35kV bus voltage, and power feeder into the post-control site data. The control response cycle is determined by the power feeder control cycle, the traction power supply monitoring system acquisition cycle, or the collaborative control node's calculation cycle. The post-control site data includes the traction substation identifier, command type, command issuance time, post-control acquisition time, post-control DC traction network voltage, post-control 35kV bus voltage, and post-control power feeder. The collaborative control node uses the traction substation identifier and the command issuance time as indexes to read the station record that has most recently completed time alignment before the command is issued; it subtracts the DC traction network voltage in the station record before the command is issued from the DC traction network voltage in the station data after control to obtain the DC traction network voltage change after command execution; it subtracts the 35kV bus voltage before the command is issued from the 35kV bus voltage after control to obtain the 35kV bus voltage change; and it subtracts the energy feeder power before the command is issued from the energy feeder power after control to obtain the energy feeder power change. The collaborative control node writes the traction substation identifier, station role, command type, command issuance time, post-control data acquisition time, DC traction network voltage changes, 35kV bus voltage changes, and power feedback changes into the same command response record. When the power feedback of the main feedback station increases after executing the main feedback power command and the 35kV bus voltage does not exceed the allowable range of the load-bearing state, the corresponding command response record serves as the basis for maintaining or continuing to accept the load. When the power feedback of the limited feeder station decreases or remains at the limited value after executing the limited feeder command, the corresponding command response record serves as the basis for the limited feeder to be effective. When the power feedback of the exiting station decreases to the exit state or approaches zero output after executing the exit command, the corresponding command response record serves as the basis for the exit to be effective. The collaborative control node uses the traction substation identifier and control cycle identifier as matching fields to associate the instruction response record generated in the current control cycle with the corresponding mismatched record; for feed-limited sites, it compares whether the DC traction network voltage and 35kV bus voltage continue to rise after the feed-limited instruction is executed; for exited sites, it compares whether the 35kV bus voltage continues to rise after the exit instruction is executed, and whether the DC traction network voltage still rises at the site; for main feedback sites and auxiliary feedback sites, it combines the sources of pending demand retained in the role record to determine whether the acceptance action causes its own 35kV bus voltage to continue to rise; When a control command is executed at the same traction substation, and the change in DC traction network voltage and the change in 35kV bus voltage are both greater than zero, the collaborative control node marks the traction substation as a reverse response station. The node then writes the traction substation identifier, current control cycle identifier, acquisition time, original station role, executed command type, DC traction network voltage change, 35kV bus voltage change, power feeder change, and the corresponding source of any mismatch record into the reverse response record. When the same traction substation is marked as a reverse response station in multiple consecutive control cycles, the number of times it appears in the reverse response record is accumulated. When the station role determination process is executed in the next control cycle, the collaborative control node reads the reverse response record formed in the previous control cycle and writes the reverse response station identifier into the role correction input item. The role correction input item, along with the mismatch record, the feedback requirements of each traction substation, the 35kV bus load status of each traction substation, and the inter-station connection relationship, enters the role determination process in the next control cycle. When the feedback site determination conditions are met in the next control cycle, i.e., the feedback requirement of the feedback site is to provide feedback or maintain feedback and the 35kV bus load status is to allow feedback, the coordinated control node first selects other feedback sites that have not been marked as feedback sites in the feedback site selection order, and then selects the current feedback site. The subsequent selection is achieved by setting the selection order field in the role record, or by reducing the priority of the feedback site when sorting the candidate sites. When a reverse response station meets the conditions for determining a feed-limited or exited station in the next control cycle, i.e., when the feedback requirement of the reverse response station is required to provide feedback or to maintain feedback and the 35kV bus load status is restricted to feedback, the collaborative control node will prioritize determining the traction substation as a feed-limited station; when the feedback requirement of the reverse response station is required to provide feedback or to maintain feedback and the 35kV bus load status is prohibited to provide feedback, the collaborative control node will prioritize determining the traction substation as an exited station. For example, the collaborative control node outputs a main feedback power command to the energy feeder device of traction substation A, a feeder limiting command to the energy feeder device of traction substation B, and an exit command to the energy feeder device of traction substation C, based on the role record. After the command is issued, the collaborative control node collects the DC traction network voltage, 35kV bus voltage, and energy feeder power of traction substations A, B, and C again, and compares them with the site records before the command was issued. If the DC traction network voltage and 35kV bus voltage continue to rise after traction substation B executes the feeder limiting command, the collaborative control node writes traction substation B into the reverse response record and lowers the selection priority of traction substation B as a feedback site in the next control cycle, or prioritizes traction substation B as a feeder limiting site or an exit site.

[0026] The working principle of this implementation method is as follows: The collaborative control node first collects and aligns the DC side data, 35kV side data, and power feeder device data of each traction substation within the collaborative section, forming a site record with the same site identifier and collection time caliber; then, it determines the feedback requirements of each traction substation based on the DC traction network voltage changes, power feeder power changes, and power feeder device operating status, and determines the 35kV bus load status of each traction substation based on the 35kV bus voltage, 35kV incoming line voltage changes, and feedback rise; when the feedback requirements do not match the 35kV bus load status, the collaborative control node classifies the corresponding traction substation as a limited-feeding site or a decommissioned site, and selects a site with permitted feedback conditions. In traction substations with inter-station connections, the main feedback station and auxiliary feedback station are identified. Subsequently, the collaborative control node outputs feedback power commands to the main and auxiliary feedback stations, feed-limiting commands to feed-limiting stations, and exit commands to exit stations. After the control commands are executed, the collaborative control node continues to collect DC traction network voltage, 35kV bus voltage, and energy feedback power. Based on the changes before and after control, it generates command response records and reverse response records. The reverse response records are then input into the role determination process of the next control cycle, so that the determination process of feedback stations, feed-limiting stations, and exit stations can be corrected according to the actual control response, thereby realizing the collaborative control of regenerative energy feedback actions of multiple traction substations.

[0027] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for coordinated control of regenerative power feedback devices in subway traction substations, characterized in that, include: S1. Obtain the DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, power supply power, and power supply device operating status of each traction substation in the coordinated section, and generate station records according to the traction substation identification and acquisition time. S2. Based on the DC traction network voltage changes, power feeder changes, and power feeder device operating status recorded at the stations, determine the feedback requirements of each traction substation, whether feedback is required, maintained, or not required, and generate feedback requirement records. S3. Based on the changes in 35kV bus voltage and 35kV incoming line voltage in the station records, as well as the corresponding increase in 35kV bus voltage when the power feeder increases, determine the 35kV bus load status of each traction substation that allows, restricts, or prohibits feedback, and generate a load record. S4. Match the feedback demand record with the load record according to the traction substation identifier, identify the feedback demand as a traction substation that needs to provide feedback or maintain feedback and whose 35kV bus load status is restricted or prohibited from providing feedback, and generate a mismatch record. S5. Based on the mismatch records, the feedback requirements of each traction substation, the 35kV bus load status of each traction substation, and the inter-station connection relationship between each traction substation, determine the feedback station, the limited feeder station, and the exit station, and generate role records. S6. Based on the role record, output feedback power command to the energy feeder device of the feedback station, output limiting feeder command to the energy feeder device of the limiting feeder station, output exit command to the energy feeder device of the exit station, and collect the DC traction network voltage change and 35kV bus voltage change after the control command is executed.

2. The method according to claim 1, characterized in that, S1 includes: S1.

1. Based on the adjacent relationship of the DC traction network and the 35kV side ring network relationship between traction substations, candidate sites for participating in coordinated control are selected from traction substations equipped with regenerative power feedback devices to form a candidate site set. S1.2 Compare the inter-site connection relationships between each candidate site in the candidate site set, and retain the candidate sites that have a DC side adjacent relationship or a 35kV side ring network relationship with at least one other candidate site as cooperative sites, thus obtaining the cooperative site set; S1.3 According to the station order and inter-station connection relationship of each collaborative station in the collaborative station set, each collaborative station is assigned to the same collaborative section, and the traction substation corresponding to each collaborative station in the collaborative section is taken as the collection object of the station record.

3. The method according to claim 2, characterized in that, S1 further includes: S1.

4. The regenerative power feedback devices configured in each traction substation within the coordinated section are used as energy feeder devices. The DC traction network voltage is read from the DC side acquisition interface of each traction substation within the coordinated section, the 35kV bus voltage and 35kV incoming line voltage are read from the 35kV side acquisition interface, and the energy feeder power and energy feeder device operating status are read from the energy feeder device to obtain the original data of the station. S1.

5. Collect the original data of the stations according to the identification of the traction substation, and align the DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, power supply power and power supply device operation status under the same traction substation identification with the time of collection to obtain the station data at the same time. S1.6 Write the station data at the same time into the data item corresponding to the traction substation identifier and the acquisition time to form a station record containing DC traction network voltage, 35kV bus voltage, 35kV incoming line voltage, power feeder power and power feeder device operating status.

4. The method according to claim 3, characterized in that, S2 includes: S2.

1. Retrieve the station records corresponding to the same traction substation identifier at the continuous acquisition time, and perform differential processing on the DC traction network voltage and power feed at the continuous acquisition time to obtain the DC traction network voltage change and power feed change. S2.

2. Screen each traction substation for feedback eligibility based on the operating status of the energy feeder. Traction substations whose energy feeder operating status is faulty or out of service are marked as traction substations that are not eligible for feedback. Traction substations whose energy feeder operating status does not indicate fault or out of service are designated as stations to be judged. S2.

3. Make corresponding judgments on the DC traction network voltage changes and energy feed power changes of the stations to be judged. Determine the stations to be judged where the DC traction network voltage changes are positive and the energy feed power changes are negative as traction substations that need feedback. Determine the stations to be judged where the energy feed power is in the output state and the DC traction network voltage changes are negative as traction substations that maintain feedback. Determine the stations to be judged where the traction substations do not have the qualification for feedback and the stations to be judged where the DC traction network voltage changes are negative and the energy feed power is not in the output state as traction substations that do not need feedback. Generate feedback demand records according to the traction substation identification.

5. The method according to claim 4, characterized in that, S3 includes: S3.

1. Retrieve the 35kV bus voltage and 35kV incoming line voltage from the records of the corresponding stations of the same traction substation. Use the difference between the upper limit of the allowed operation of the 35kV bus and the 35kV bus voltage as the basic margin. When the 35kV incoming line voltage increases, deduct the increase in 35kV incoming line voltage from the basic margin to obtain the bus voltage margin. S3.2 Select the data collection period when the power feeder increases under the same traction substation identification, take the increase in 35kV bus voltage during the data collection period as the feedback rise amount, and write the feedback rise amount and the power feeder increase amount into the feedback rise record accordingly. S3.

3. Compare the bus voltage margin with the feedback rise amount. When the bus voltage margin is greater than or equal to the feedback rise amount, determine the 35kV bus load status as permissible feedback. When the bus voltage margin is greater than zero and less than the feedback rise amount, determine the 35kV bus load status as restricted feedback. When the bus voltage margin is less than or equal to zero, determine the 35kV bus load status as prohibited feedback. Generate a load record according to the traction substation identification.

6. The method according to claim 5, characterized in that, S4 includes: S4.1 Using the traction substation identifier and acquisition time as matching fields, the feedback demand records and load records within the same control cycle are paired to obtain the site matching records; S4.2 In the site matching record, traction substations with feedback requirements of "required feedback" or "keep feedback" and 35kV bus load status of "restricted feedback" are marked as limited feeder mismatched sites, and traction substations with feedback requirements of "required feedback" or "keep feedback" and 35kV bus load status of "prohibited feedback" are marked as exited mismatched sites. S4.3 Write the feeder mismatch site, exit mismatch site, corresponding feedback requirement type, 35kV bus load status and acquisition time into the same record to form a mismatch record.

7. The method according to claim 6, characterized in that, S5 includes: S5.1 Read the feed-limited mismatched stations and exit mismatched stations in the mismatched records, and set the feed-limited mismatched stations as feed-limited pending stations and the exit mismatched stations as exit pending stations. S5.2 When the feedback requirement of each traction substation is to require feedback or maintain feedback and the 35kV bus load status is to allow feedback, the corresponding traction substation shall be included in the feedback site set. When the traction substation belongs to the limited feeder undetermined site, it shall be determined as a limited feeder site. When the traction substation belongs to the exit undetermined site, it shall be determined as an exit site. S5.3 Write the feedback site set, limited feedback sites, exited sites, and corresponding feedback requirements, 35kV bus load status, and site source into the role record.

8. The method according to claim 7, characterized in that, The S5 also includes: S5.

4. The feedback requirements corresponding to the limited feeder station and the exit station are identified as the requirements to be accepted. From the set of feedback stations, traction substations that have inter-station connection with the limited feeder station or the exit station and whose 35kV bus load status allows feedback are selected to obtain the candidate stations to be accepted. S5.5 Compare the inter-station connection relationships between the candidate sites and the feed-limited or withdrawn sites, and determine the candidate sites with direct inter-station connection relationships as the main feed-in sites, and determine the candidate sites connected through other traction substations as auxiliary feed-in sites. S5.6 Write the main feedback site, auxiliary feedback site, limited feedback site, and exit site into the role record respectively, and retain the pending needs undertaken by the main feedback site or auxiliary feedback site in the role record.

9. The method according to claim 8, characterized in that, S6 includes: S6.1 Read the main feedback station, auxiliary feedback station, limited feedback station and exit station in the role record, and retrieve the feedback requirements, 35kV bus load status and power of each station to form an instruction object record; S6.2 According to the instruction object record, output the main feedback power instruction to the energy feeder device of the main feedback station, output the auxiliary feedback power instruction to the energy feeder device of the auxiliary feedback station, output the limiting energy feeder instruction to the energy feeder device of the limiting feeder station to reduce the energy feeder power or maintain the limited energy feeder power, and output the exit instruction to the energy feeder device of the exit station to stop feeding back to the 35kV bus. S6.3 After the feedback power command, feed-limiting command and exit command are issued, the DC traction network voltage, 35kV bus voltage and feed-in power of the corresponding station are collected, and the station data after control is formed based on the time of command issuance.

10. The method according to claim 9, characterized in that, S6 further includes: S6.4 Compare the control data of the stations with the station records before the command was issued to obtain the changes in DC traction network voltage, 35kV bus voltage and power feeder, and form a command response record. S6.

5. Compare the command response record and mismatch record. If the DC traction network voltage continues to rise and the 35kV bus voltage continues to rise after the control command is executed at the same traction substation, mark the corresponding traction substation as a reverse response station and generate a reverse response record. S6.6 When executing S5 in the next control cycle, the reverse response record is used as the role correction input; when the reverse response station meets the feedback station determination conditions, the reverse response station is placed after other feedback stations for selection; when the reverse response station meets the limited feedback station or exit station determination conditions, the reverse response station is preferentially determined as a limited feedback station or exit station.

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