A control method and system for a rail transit converter

Abstract

The present application discloses a control method and system for a rail transit converter, which is applied to a rail transit system. The rail transit system includes: a plurality of traction substations; each traction substation includes at least one converter; the method includes: obtaining at least the position information and operating status information of a train through a communication network; the train is all trains between the (n - 1)-th traction substation and the (n + 1)-th traction substation; the (n - 1)-th traction substation and the (n + 1)-th traction substation are the traction substations closest to the left and right of the n-th traction substation; the n-th traction substation is any traction substation; obtaining a slope influence value corresponding to the n-th traction substation according to the position information and operating status information of the train; and adjusting the output characteristic curve of the corresponding converter according to the slope influence value. The present application can adjust the output characteristic curve of the converter in real time according to the position information and operating status information of the train, realize coordinated control, and optimize power distribution.

Description

Technical Field

[0001] This application relates to the technical field of rail transit, and in particular to a control method and system for a rail transit converter. Background Art

[0002] The traction power supply in a rail transit system is the core of rail transit operation, undertaking multiple functions such as power conversion, transmission, and feedback. A bidirectional converter (hereinafter referred to as a converter) can be used in a rail transit system to achieve traction power supply. The converter can realize bidirectional energy flow and has both the train traction and energy feedback capabilities, which is an important trend for the future development of rail transit systems.

[0003] However, in the prior art, the converter devices in different traction substations usually adopt an independent control method, and there is no communication or coordinated control between the converters. Once the converter is debugged, the output characteristic curve of the converter is completely determined and cannot be adjusted in real time. Therefore, it is difficult to optimize power distribution and the line loss is relatively large. Summary of the Invention

[0004] In view of this, this application provides a control method and system for a rail transit converter, which can adjust the output characteristic curve of the converter in real time and achieve coordinated control.

[0005] To solve the above problems, the technical solutions provided in this application are as follows:

[0006] In the first aspect of this application, a control method for a rail transit converter is provided, which is applied to a rail transit system. The rail transit system includes: a plurality of traction substations; each traction substation includes at least one converter;

[0007] The method includes:

[0008] Obtain at least the position information and operation status information of the train through a communication network; the train is all trains between the (n - 1)-th traction substation and the (n + 1)-th traction substation; the (n - 1)-th traction substation and the (n + 1)-th traction substation are the traction substations closest to the left and right of the n-th traction substation respectively; the n-th traction substation is any traction substation;

[0009] Obtain the slope influence value corresponding to the n-th traction substation according to the position information and operation status information of the train;

[0010] Adjust the output characteristic curve of the corresponding converter according to the slope influence value.

[0011] Preferably, obtaining the slope influence value corresponding to the n-th traction substation according to the position information and operation status information of the train includes:

[0012] According to the position information and operating status information of the train, when the train is closer to the nth traction substation, the control slope influence value is greater, and the slope influence value corresponding to the nth traction substation is obtained.

[0013] Preferably, obtaining the slope influence value corresponding to the nth traction substation according to the position information and operating status information of the train includes:

[0014] According to the position information and operating status information of the train, obtain the influence offset value of each train on the converter of the nth traction substation among all trains;

[0015] Sum up the influence offset values corresponding to each train to obtain the slope influence value corresponding to the nth traction substation.

[0016] Preferably, the position information and operating status information of the train include:

[0017] The distance of each train to the nearest traction substation on the left, the distance of each train to the nearest traction substation on the right, the relative position of each train to the nth traction substation, and the operating status information of each train.

[0018] Preferably, when the mth train is on the left side of the nth traction substation, the relative position is set to 0; otherwise, it is set to 1; the mth train is any train between the (n - 1)th traction substation and the (n + 1)th traction substation;

[0019] When the mth train is being towed, the operating status information is set to 1; when the mth train is braking, the operating status information is set to -1; in other cases, the operating status information is set to 0;

[0020] According to the distance of the mth train to the nearest traction substation on the left, the distance of the mth train to the nearest traction substation on the right, and the relative position of the mth train, obtain the first parameter;

[0021] Multiply the first parameter by the operating status information of the mth train and a preset proportionality coefficient to obtain the influence offset value corresponding to the mth train.

[0022] Preferably, adjusting the output characteristic curve of the corresponding converter according to the slope influence value includes:

[0023] Take the sum of the slope influence value and the preset minimum limit slope as the first slope;

[0024] When the first slope is less than or equal to the preset maximum limit slope, adjust the slope of the output characteristic curve of the converter to the first slope;

[0025] When the first slope is greater than the preset maximum limit slope, adjust the slope of the output characteristic curve of the converter to the preset maximum limit slope.

[0026] Preferably, it further includes:

[0027] Obtain the output power of the converter;

[0028] When the slope of the output characteristic curve of the converter reaches the preset maximum limit slope and the output power of the converter reaches the preset threshold, control the converter of the traction substation closest to the nth traction substation to supplement and provide power.

[0029] The second aspect of this application provides a rail transit converter control system, including: a controller and multiple traction substations; each traction substation includes at least one converter;

[0030] The controller is used to obtain at least the position information and operating status information of the train through the communication network; the train is all trains between the (n - 1)th traction substation and the (n + 1)th traction substation; the (n - 1)th traction substation and the (n + 1)th traction substation are the traction substations closest to the left and right of the nth traction substation; the nth traction substation is any traction substation; according to the position information and operating status information of the train, obtain the slope influence value corresponding to the nth traction substation; according to the slope influence value, adjust the output characteristic curve of the corresponding converter.

[0031] Preferably, the controller is specifically used to, according to the position information and operating status information of the train, when the train is closer to the nth traction substation, control the slope influence value to be larger, and obtain the slope influence value corresponding to the nth traction substation.

[0032] Preferably, the controller is specifically used to, according to the position information and operating status information of the train, obtain the influence offset value of each train on the converter of the nth traction substation among all trains; sum the influence offset values corresponding to each train to obtain the slope influence value corresponding to the nth traction substation.

[0033] Preferably, the position information and operating status information of the train include:

[0034] The distance of each train to the traction substation closest to the left, the distance of each train to the traction substation closest to the right, the relative position of each train and the nth traction substation, and the operating status information of each train.

[0035] Preferably, the controller is specifically used to, when the mth train is on the left side of the nth traction substation, set the relative position to 0; otherwise, set it to 1; the mth train is any train between the (n - 1)th traction substation and the (n + 1)th traction substation; when the mth train is being towed, set the operating status information to 1; when the mth train is braking, set the operating status information to -1; in other cases, set the operating status information to 0;

[0036] The controller is further specifically configured to obtain a first parameter according to the distance between the m-th train and the traction substation closest to the left side, the distance between the m-th train and the traction substation closest to the right side, and the relative position of the m-th train;

[0037] Multiply the first parameter by the operating state information of the m-th train and a preset proportionality coefficient to obtain an influence offset value corresponding to the m-th train.

[0038] Preferably, the controller is specifically configured to use the sum of the slope influence value and the preset minimum limit slope as the first slope; when the first slope is less than or equal to the preset maximum limit slope, adjust the slope of the output characteristic curve of the converter to the first slope; when the first slope is greater than the preset maximum limit slope, adjust the slope of the output characteristic curve of the converter to the preset maximum limit slope;

[0039] The controller is further configured to obtain the output power of the converter; when the slope of the output characteristic curve of the converter reaches the preset maximum limit slope and the output power of the converter reaches the preset threshold, control the converter of the traction substation closest to the n-th traction substation to supplement and provide power.

[0040] Thus, the present application has the following beneficial effects:

[0041] The rail transit converter control method provided by the present application obtains at least the position information and operating state information of the train through a communication network, where the train is all trains between the (n - 1)-th traction substation and the (n + 1)-th traction substation; the (n - 1)-th traction substation and the (n + 1)-th traction substation are the traction substations closest to the left and right sides of the n-th traction substation; the n-th traction substation is any traction substation; obtain the slope influence value corresponding to the n-th traction substation according to the position information and operating state information of the train; adjust the output characteristic curve of the corresponding converter according to the slope influence value. The rail transit converter control method provided by the present application can adjust the output characteristic curve of the converter of the n-th traction substation in real time according to the information of the train, achieve coordinated control, optimize power distribution, and reduce line losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of a rail transit system;

[0043] Figure 2 It is a flowchart of a rail transit converter control method provided by an embodiment of the present application;

[0044] Figure 3 It is a flowchart of another rail transit converter control method provided by an embodiment of the present application;

[0045] Figure 4 It is a schematic diagram of a rail transit system provided by an embodiment of the present application;

[0046] Figure 5 Schematic diagram of the output characteristic curve of a converter provided by an embodiment of the present application;

[0047] Figure 6 Schematic diagram of a rail transit converter control system provided by an embodiment of the present application. Detailed implementation manners

[0048] In order to enable those skilled in the art to better understand and implement the technical solutions of the present application, the specific application scenarios of the present application are introduced below.

[0049] Refer to Figure 1 , which is a schematic diagram of a rail transit system.

[0050] The rail transit system includes: a plurality of traction substations; the plurality of traction substations include: traction substation 1, traction substation 2 up to traction substation N. Each traction substation includes at least one set of converter and its supporting equipment.

[0051] The first end of each traction substation is connected to the AC bus, and the second end is connected to the DC traction network. The DC traction network includes: catenary and rail. The train runs on the rail.

[0052] When the train needs to start or accelerate, the converter in the traction substation converts the grid AC power into DC power; when the train brakes, the converter converts the braking energy of the train into AC power and feeds it back to the grid, which can save electric energy.

[0053] However, for the same DC traction network, the converters in different traction substations usually adopt an independent control method, and there is no communication or coordinated control between the converters. The output of the converter is only controlled according to the magnitude of the DC bus voltage or other electrical quantities of the corresponding traction substation. Once the converter equipment is debugged, the output characteristic curve of the converter is completely determined, and it is impossible to adjust the output characteristic curve of the converter of the adjacent traction substation in real time according to the light load condition and heavy load condition at different positions of the DC traction network. Therefore, it is difficult to achieve power coordinated control, and it is difficult to further optimize power distribution, reduce line losses, and suppress DC traction network voltage fluctuations.

[0054] For example, when multiple trains start and accelerate simultaneously near the same traction substation, due to the lack of power coordinated control, the converters of the adjacent traction substations can only work according to the preset output characteristic curve, resulting in a significant drop in the DC voltage near the traction substation. At the same time, it may lead to an increase in line losses due to cross-regional power supply; similarly, when multiple trains decelerate and brake simultaneously near the same traction substation, it will cause a rapid increase in the DC voltage near the traction substation, and it may also lead to more cross-regional energy feedback and an increase in line losses.

[0055] The embodiments of the present application will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0056] Refer to Figure 2 , which is a flowchart of a rail transit converter control method provided by an embodiment of the present application.

[0057] The rail transit converter control method provided by the embodiments of the present application is applied to a rail transit system, and the rail transit system includes: a plurality of traction substations; each traction substation includes at least one converter.

[0058] It should be understood that the present application does not specifically limit the specific topological structure of the rail transit system. For example, each traction substation may further include other devices such as transformers.

[0059] The rail transit converter control method provided by the embodiments of the present application includes:

[0060] S101: Obtain at least the position information and operating status information of the train through a communication network.

[0061] The train is all trains between the (n - 1)th traction substation and the (n + 1)th traction substation; the (n - 1)th traction substation and the (n + 1)th traction substation are the traction substations closest to the left and right of the nth traction substation; the nth traction substation is any traction substation.

[0062] The present application does not specifically limit the specific implementation manner of the communication network. For example, when the rail transit system is a subway system, a dedicated high-speed subway communication network can be specifically adopted to collect and obtain train information in real time.

[0063] Of course, for more accurate control, in addition to the position information and operating status information of the train, the embodiments of the present application can also obtain more information, such as: the number and numbers of trains in a specified area, the output power of the converter, etc.

[0064] S102: Obtain the slope influence value corresponding to the nth traction substation according to the position information and operating status information of the train.

[0065] There are various specific implementation manners for step S102. For example: the slope influence value can be determined according to the distance between the train and the nth traction substation. The closer the distance, the more the converter outputs, and the greater the slope influence value. The present application does not make specific limitations on this.

[0066] Specifically, since the greater the slope influence value, the greater the traction output or energy feedback output of the converter, the more the nth traction substation outputs, the greater the corresponding slope influence value.

[0067] S103: Adjust the output characteristic curve of the corresponding converter according to the slope influence value.

[0068] This application does not specifically limit the specific implementation method of adjusting the output characteristic curve of the converter. For example, the converter can adopt a double-loop control method. The inner loop is a common current-loop control, and the outer loop adopts a power-loop control. The given value of the power loop is determined by the output characteristic curve.

[0069] The rail transit converter control method provided by the embodiments of this application obtains at least the position information and operating status information of the train through a communication network. The train is all trains between the (n - 1)th traction substation and the (n + 1)th traction substation; the nth traction substation is any traction substation; obtain the slope influence value corresponding to the nth traction substation according to the position information and operating status information of the train; adjust the output characteristic curve of the corresponding converter according to the slope influence value. The rail transit converter control method provided by the embodiments of this application can, according to the information of the train, adjust the output characteristic curve of the converter of the nth traction substation in real time, achieve coordinated control, optimize power distribution, and reduce line losses.

[0070] The following introduces a possible specific implementation method in conjunction with the accompanying drawings.

[0071] See Figure 3 , this figure is a flowchart of another rail transit converter control method provided by the embodiments of this application.

[0072] This method includes:

[0073] S201: Obtain at least the distance from each train to the nearest traction substation on the left, the distance from each train to the nearest traction substation on the right, the relative position of each train and the nth traction substation, the operating status information of each train, and the output power of the converter corresponding to the nth traction substation through a communication network.

[0074] Same as the above embodiment, the trains for which information needs to be obtained are all trains between the (n - 1)th traction substation and the (n + 1)th traction substation; the (n - 1)th traction substation and the (n + 1)th traction substation are the nearest traction substations on the left and right of the nth traction substation; the nth traction substation is any traction substation.

[0075] To enable those skilled in the art to better understand the specific information obtained in step S201, the following will be introduced in detail in conjunction with the accompanying drawings.

[0076] See Figure 4 , this figure is a schematic diagram of a rail transit system provided by the embodiments of this application.

[0077] The rail transit system includes: a plurality of traction substations. The plurality of traction substations includes: the first traction substation P1 to the Nth traction substation PN; where the nth traction substation Pn is one of the plurality of traction substations; the traction substation adjacent to the left of the nth traction substation Pn is the (n - 1)th traction substation Pn - 1; the traction substation adjacent to the right of the nth traction substation Pn is the (n + 1)th traction substation Pn + 1.

[0078] When the number of trains Mn between the (n - 1)th traction substation Pn - 1 and the (n + 1)th traction substation Pn + 1 is greater than 0, the trains are sequentially numbered Pnm from left to right (1 ≤ m ≤ Mn). For the Pnm train, the distance to the traction substation closest to it on the left is denoted as S L_m , and the distance to the traction substation closest to it on the right is denoted as S R_m , and the relative position F of the train with respect to the nth traction substation is assigned m , and the train operation state information is denoted as R m .

[0079] Specifically, when the mth train is on the left of the nth traction substation, the relative position is set to 0; otherwise, it is set to 1; the mth train is any train between the (n - 1)th traction substation and the (n + 1)th traction substation.

[0080] When the mth train is being towed, the operation state information is set to 1; when the mth train is braking, the operation state information is set to -1; in other cases, the operation state information is set to 0.

[0081] S202: According to the information obtained in step S201, obtain the influence offset value of each train on the converter of the nth traction substation among all trains.

[0082] Step S202 can specifically obtain a first parameter according to the distance of the mth train to the traction substation closest to it on the left, the distance of the mth train to the traction substation closest to it on the right, and the relative position of the mth train; multiply the first parameter by the operation state information of the mth train and a preset proportionality coefficient to obtain the influence offset value corresponding to the mth train.

[0083] Specifically, the influence offset value corresponding to each train is calculated in the following way:

[0084] In the formula, Δk m is the influence offset value of the mth train, k is the preset proportionality coefficient, R m is the operation state information of the mth train, F m is the relative position of the mth train, S L_m is the distance of the mth train to the traction substation closest to it on the left, S R_mis the distance from the mth train to the nearest traction substation on the right.

[0085] From the above formula, we can see that the first parameter, The part represents the influence of the train's position on the output power slope of the bidirectional converter in the current traction substation. It takes values between [0,1]. When the train is located at the adjacent Pn-1 traction substation or Pn+1 traction substation (i.e., the farthest adjacent section to the left and right of the current traction substation), its value takes the minimum value of 0. As the distance between the train and the nth traction substation Pn decreases, its value increases monotonically. When the distance between the train and the current traction substation is 0 (i.e., the train is located at the current traction substation), its value takes the maximum value of 1.

[0086] R m It indicates the influence of the train running status on the output power slope of the bidirectional converter in the current traction substation. That is, the influence of train traction and braking is opposite. When the train stops, the influence is 0 (i.e. no influence).

[0087] There should be a certain proportional relationship between the calculated value and the bias value affecting the slope, so the proportional coefficient k is set.

[0088] Of course, the above formula is only one possible specific implementation method, and other formulas can also be used for calculation; this application does not make specific limitations on this.

[0089] S203: Sum the impact bias values corresponding to each train to obtain the slope impact value corresponding to the nth traction substation.

[0090]

[0091] Step S203 sums the impact bias values of all trains in the specified area to obtain the slope impact value. Therefore, when one train is traction and another train is braking, the train operation status information has opposite values, which has opposite effects on the calculation result of the slope impact value of the output power of the bidirectional converter of the traction substation. Therefore, the electric energy generated by the train deceleration and braking will be used preferentially on the DC side for traction acceleration of adjacent trains in the section, and the converter output curve will be adjusted according to the final net power, reducing the loss caused by the energy transmission back and forth between the DC traction network and the AC power grid.

[0092] S204: taking the sum of the slope influence value and the preset minimum limit slope as the first slope.

[0093] S205: When the first slope is less than or equal to the preset maximum limit slope, adjust the slope of the output characteristic curve of the converter to the first slope.

[0094] S206: When the first slope is greater than the preset maximum limit slope, adjust the slope of the output characteristic curve of the converter to the preset maximum limit slope.

[0095]

[0096] where k n is the slope of the output characteristic curve of the converter, k min is the minimum defined slope, k max is the maximum defined slope, Δk Pn is the slope influence value corresponding to Pn of the nth traction substation, and Mn is the number of trains in the specified area.

[0097] It should be understood that in order to ensure the stable operation of the converter, those skilled in the art often set the minimum defined slope and the maximum defined slope of the output characteristic curve of the converter. If the slope exceeds the range, it will affect the performance and safety of the converter.

[0098] Therefore, when the first slope is greater than the preset maximum defined slope, the slope of the output characteristic curve of the converter is controlled to be the preset maximum defined slope, which ensures the stability of the converter while maximizing the output power.

[0099] Steps S204 - S206 not only realize the adjustment of the output characteristic curve of the converter by the slope influence value, but also further ensure the stability of the converter.

[0100] The method further includes: when the slope of the output characteristic curve of the converter reaches the preset maximum defined slope, and the traction power or the energy feedback power of the converter reaches the preset threshold, controlling the converter of the traction substation closest to the nth traction substation to supplement and provide power.

[0101] The power provided by the converter of the nth traction substation cannot meet the train demand, that is, the slope of the output characteristic curve reaches the preset maximum defined slope, and the traction power or the energy feedback power of the converter reaches the preset threshold. Therefore, it is necessary to control other traction substations to supplement the power shortage of the nth traction substation to support the stability of the DC bus voltage.

[0102] Considering economy and the need to recover as soon as possible in extreme cases, specifically control the traction substation closest to the nth traction substation to supplement; preferentially dispatch the bidirectional converters in the Pn - 1 and / or Pn + 1 traction substations closest to provide the power shortage, that is, using the maximum defined value k max as the slope influence value of the converter in the Pn - 1 and / or Pn + 1 traction substations, quickly increase the output to provide traction energy or perform energy feedback to maintain the stability of the DC traction bus voltage.

[0103] The rail transit converter control method provided by the embodiments of the present application specifically considers the influence of aspects such as the number of trains, train positions, and train operating states on the slope influence value, and also considers the stability of the converter's own operation, controlling the slope of the converter output characteristic curve between the minimum limit value and the maximum limit value; controlling the slope of the converter output characteristic curve to be the sum of the minimum limit value and the slope influence value, and if it exceeds the maximum limit value, output according to the slope of the maximum limit value, ensuring the stability of the converter; also considering the problem of quickly compensating for power deficits in extreme cases. When the slope of the converter output characteristic curve reaches the preset maximum limit slope and the traction power or energy feedback power of the converter reaches the preset threshold, control the converter of the traction substation closest to the nth traction substation to supplement and provide power, which can ensure the stability of the DC bus voltage in extreme cases and quickly resume normal operation.

[0104] Specifically, the above embodiments can all be implemented by the controller sending the slope influence value to the converter.

[0105] In some embodiments, the converter adjusts the output characteristic curve according to the slope influence value, which can be achieved through the power loop. The converter adopts a double-loop control method, with the inner loop being current control and the outer loop using power loop control.

[0106] See Figure 5 , which is a schematic diagram of the output characteristic curve of a converter provided by the embodiments of the present application.

[0107] Specifically, for more stable and accurate control, the output characteristic curve of the converter can be divided into 7 intervals according to different DC bus voltages.

[0108] Interval 1: When the DC voltage U dc ≤U1, the converter determines that the DC traction network has an undervoltage fault, and the converter output is cut off.

[0109] Interval 2: When the DC voltage U1 < U dc ≤U2, at this time, due to the heavy traction load, the converter performs constant power traction with the maximum output power.

[0110] Interval 3: When the DC voltage U2 < U dc <U rec0 , at this time, the converter operates in a variable slope power droop traction output state, and the slope k n takes values in the range of [k min , k max , and the specific steps of the above embodiments are used for adjustment. As Figure 5 can be seen, as the slope increases, the power given value is larger under the same DC voltage, that is, the traction output of the bidirectional converter is greater.

[0111] Interval 4: When the DC voltage U rec0 ≤U dc ≤U inv0 The converter operates in a state close to no-load. At this time, a smaller slope can reduce the power circulating current to a certain extent and avoid large fluctuations in the DC voltage during no-load.

[0112] Interval 5: When the DC voltage U inv0 <U dc <U3, the converter operates in a variable-slope power droop energy feedback state. The slope k n takes values in the range of [k min , k max . Adjustment is carried out using the specific steps of the above embodiments. As can be seen from Figure 4 the larger the slope, the larger the power reference given value at the same DC voltage, that is, the greater the energy feedback output of the bidirectional converter.

[0113] Interval 6: When the DC voltage U3 ≤ U dc <U4, since there is more energy to be fed back and the voltage is higher on the DC bus, the converter performs constant-power energy feedback at the maximum power.

[0114] Interval 7: When the DC voltage U dc ≥U4, the converter determines that an overvoltage fault has occurred in the DC traction network, and the output of the converter is cut off.

[0115] It should be understood that in the above embodiments, to obtain the slope influence value and adjust the slope of the output characteristic curve, specifically in the segmented control process, the slopes of Interval 3 and Interval 5 are adjusted, and the slopes of the other intervals remain unchanged; for example, in the extreme case where the power provided by the converter of the nth traction substation cannot meet the train demand, it appears in Interval 2 or Interval 6.

[0116] Based on the rail transit converter control method provided by the above embodiments, the embodiments of the present application also provide a rail transit converter control system, which will be introduced in detail below with reference to the accompanying drawings.

[0117] See Figure 6 which is a schematic diagram of a rail transit converter control system provided by the embodiments of the present application.

[0118] The rail transit converter control system provided by the embodiments of the present application includes: a controller 100 and multiple traction substations; the multiple traction substations include: the first traction substation P1, the second traction substation P2 up to the Nth traction substation PN.

[0119] Each traction substation includes at least one converter.

[0120] The present application does not specifically limit the specific topology of each traction substation. The figure also includes a transformer. Of course, other equipment and devices may also be included.

[0121] The first end of each traction substation is connected to the AC power grid, and the second end is connected to the DC traction network. Trains run in the DC traction network.

[0122] The controller 100 is configured to obtain at least the position information and operating status information of the train through a communication network. The train is all trains between the (n - 1)-th traction substation and the (n + 1)-th traction substation. The (n - 1)-th traction substation and the (n + 1)-th traction substation are the traction substations closest to the left and right of the n-th traction substation respectively. The n-th traction substation is any traction substation. According to the position information and operating status information of the train, obtain the slope influence value corresponding to the n-th traction substation. According to the slope influence value, adjust the output characteristic curve of the corresponding converter.

[0123] Of course, for more accurate control, in addition to the position information and operating status information of the train, the controller 100 may also obtain more information, such as: the number and serial numbers of trains within a specified area, information of the converter, etc. The present application does not make specific limitations thereto.

[0124] There are various specific implementation manners for the controller 100 to obtain the slope influence value. For example, it can be based on the distance of the train from the n-th traction substation. The closer the distance, the more the converter outputs, and the greater the slope influence value. The present application does not make specific limitations thereto.

[0125] Since the greater the slope influence value, the greater the traction output or the energy feedback output of the converter, the greater the output of the n-th traction substation, the greater the corresponding slope influence value.

[0126] The rail transit converter control system provided by the embodiments of the present application includes: a controller and multiple traction substations; each traction substation includes at least one converter; the controller obtains at least the position information and operating status information of the train through a communication network. The train is all trains between the (n - 1)-th traction substation and the (n + 1)-th traction substation. The n-th traction substation is any traction substation. The controller obtains the slope influence value corresponding to the n-th traction substation according to the position information and operating status information of the train. According to the slope influence value, adjust the output characteristic curve of the corresponding converter. In the rail transit converter control system provided by the embodiments of the present application, the controller can adjust the output characteristic curve of the converter of the n-th traction substation in real time according to the information of the train, realize the coordinated control of the converter, optimize the power distribution, and reduce the line loss.

[0127] In some embodiments, the controller is specifically configured to obtain the slope influence value corresponding to the nth traction substation according to the position information and operating state information of the train, where the closer the train is to the nth traction substation, the greater the controlled slope influence value.

[0128] In some embodiments, the controller is specifically configured to obtain the influence offset value of the converter of the nth traction substation for each train among all trains according to the position information and operating state information of the train; sum the influence offset values corresponding to each train to obtain the slope influence value corresponding to the nth traction substation.

[0129] Specifically, the position information and operating state information of the train include:

[0130] The distance of each train to the nearest traction substation on the left, the distance of each train to the nearest traction substation on the right, the relative position of each train to the nth traction substation, and the operating state information of each train.

[0131] The controller is specifically configured to set the relative position to 0 when the mth train is on the left side of the nth traction substation; otherwise, set it to 1; the mth train is any train between the (n - 1)th traction substation and the (n + 1)th traction substation; when the mth train is being towed, set the operating state information to 1; when the mth train is braking, set the operating state information to -1; in other cases, set the operating state information to 0.

[0132] The controller can specifically obtain a first parameter according to the distance of the mth train to the nearest traction substation on the left, the distance of the mth train to the nearest traction substation on the right, and the relative position of the mth train; multiply the first parameter by the operating state information of the mth train and a preset proportionality coefficient to obtain the influence offset value corresponding to the mth train.

[0133] For example: The influence offset value corresponding to each train is calculated in the following manner:

[0134] In the formula, is the first parameter; Δk m is the influence offset value of the mth train, k is the preset proportionality coefficient, R m is the operating state information of the mth train, F m is the relative position of the mth train, S L_m is the distance of the mth train to the nearest traction substation on the left, S R_m is the distance of the mth train to the nearest traction substation on the right.

[0135] In some embodiments, the controller is specifically configured to use the sum of the slope influence value and the preset minimum defined slope as the first slope; when the first slope is less than or equal to the preset maximum defined slope, adjust the slope of the output characteristic curve of the converter to the first slope; when the first slope is greater than the preset maximum defined slope, adjust the slope of the output characteristic curve of the converter to the preset maximum defined slope.

[0136] It should be understood that in order to ensure the stable operation of the converter, the controller needs to control the slope of the output characteristic curve of the converter between the minimum defined slope and the maximum defined slope. If the slope exceeds the range, it will affect the performance and safety of the converter.

[0137] The controller is further configured to, when the slope of the output characteristic curve of the converter reaches the preset maximum defined slope, and the traction power or the energy feedback power of the converter reaches the preset threshold, control the converter of the traction substation closest to the nth traction substation to supplement and provide power.

[0138] When the power provided by the converter of the nth traction substation cannot meet the train's demand, that is, the slope of the output characteristic curve reaches the preset maximum defined slope, and the traction power or the energy feedback power of the converter reaches the preset threshold, the controller needs to control other traction substations to supplement the power deficit for the nth traction substation to support the stability of the DC bus voltage. Preferably, first control the traction substation closest to supplement the power deficit.

[0139] In some embodiments, the converter adjusts the output characteristic curve according to the slope influence value issued by the controller, which can be achieved through the power loop. The converter adopts a double-loop control method, with the inner loop for current control and the outer loop for power loop control. The power loop control can specifically adopt multi-level control, that is, control different output powers according to different DC bus voltages.

[0140] It should be noted that the various embodiments in this specification are described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other. For the systems or devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0141] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a rail transit converter, characterized in that, Applied to a rail transit system, the rail transit system includes: a plurality of traction substations; each of the traction substations includes at least one converter; The method includes: Obtaining at least the position information and operating status information of the train through a communication network; the train is all trains between the (n - 1)th traction substation and the (n + 1)th traction substation; the (n - 1)th traction substation and the (n + 1)th traction substation are the traction substations closest in distance to the left and right of the nth traction substation respectively; the nth traction substation is any traction substation; Obtaining the slope influence value corresponding to the nth traction substation according to the position information and operating status information of the train; Taking the sum of the slope influence value and a preset minimum limit slope as the first slope; When the first slope is less than or equal to a preset maximum limit slope, adjusting the slope of the output characteristic curve of the converter to the first slope; When the first slope is greater than the preset maximum limit slope, adjusting the slope of the output characteristic curve of the converter to the preset maximum limit slope.

2. The method according to claim 1, wherein The obtaining the slope influence value corresponding to the nth traction substation according to the position information and operating status information of the train includes: According to the position information and operating status information of the train, when the distance of the train from the nth traction substation is closer, controlling the slope influence value to be larger, and obtaining the slope influence value corresponding to the nth traction substation.

3. The method according to claim 2, wherein The obtaining the slope influence value corresponding to the nth traction substation according to the position information and operating status information of the train includes: Obtaining the influence offset value of each train in all the trains on the converter of the nth traction substation according to the position information and operating status information of the train; Summing up the influence offset values corresponding to each train to obtain the slope influence value corresponding to the nth traction substation.

4. The method according to claim 3, characterized in that The position information and operating status information of the train include: The distance of each train to the traction substation closest in distance to the left, the distance of each train to the traction substation closest in distance to the right, the relative position of each train and the nth traction substation, and the operating status information of each train.

5. The method according to claim 4, wherein When the mth train is on the left side of the nth traction substation, the relative position is set to 0; otherwise, it is set to 1; the mth train is any train between the (n - 1)th traction substation and the (n + 1)th traction substation; When the mth train is being towed, the operating status information is set to 1; when the mth train is braking, the operating status information is set to -1; in other cases, the operating status information is set to 0; Obtaining a first parameter according to the distance of the mth train to the traction substation closest in distance to the left, the distance of the mth train to the traction substation closest in distance to the right, and the relative position of the mth train; Multiplying the first parameter by the operating status information of the mth train and a preset proportionality coefficient to obtain the influence offset value corresponding to the mth train.

6. The method according to claim 1, wherein It further includes: Obtaining the output power of the converter; When the slope of the output characteristic curve of the converter reaches the preset maximum limit slope and the output power of the converter reaches the preset threshold, control the converter of the traction substation closest to the nth traction substation to supplement and provide power.

7. A control system for a rail transit converter, characterized in that, Including: A controller and multiple traction substations; each of the traction substations includes at least one converter; The controller is used to obtain at least the position information and operation status information of the train through a communication network; The train is all the trains between the (n - 1)th traction substation and the (n + 1)th traction substation; the (n - 1)th traction substation and the (n + 1)th traction substation are the traction substations closest to the left and right of the nth traction substation; The nth traction substation is any traction substation; according to the position information and operation status information of the train, obtain the slope influence value corresponding to the nth traction substation; take the sum of the slope influence value and the preset minimum limit slope as the first slope; when the first slope is less than or equal to the preset maximum limit slope, adjust the slope of the output characteristic curve of the converter to the first slope; when the first slope is greater than the preset maximum limit slope, adjust the slope of the output characteristic curve of the converter to the preset maximum limit slope.

8. The system according to claim 7, wherein The controller is specifically used to, according to the position information and operation status information of the train, when the train is closer to the nth traction substation, control the slope influence value to be larger to obtain the slope influence value corresponding to the nth traction substation.

9. The system according to claim 8, wherein The controller is specifically used to, according to the position information and operation status information of the train, obtain the influence offset value of each train on the converter of the nth traction substation among all the trains; sum up the influence offset values corresponding to each train to obtain the slope influence value corresponding to the nth traction substation.

10. The system according to claim 9, wherein The position information and operation status information of the train include: The distance of each train to the traction substation closest to the left, the distance of each train to the traction substation closest to the right, the relative position of each train and the nth traction substation, and the operation status information of each train.

11. The system according to claim 10, wherein, The controller is specifically used to, when the mth train is on the left side of the nth traction substation, set the relative position to 0; otherwise, set it to 1; the mth train is any train between the (n - 1)th traction substation and the (n + 1)th traction substation; When the mth train is being towed, set the operation status information to 1; when the mth train is braking, set the operation status information to -1; in other cases, set the operation status information to 0; The controller is also specifically used to obtain a first parameter according to the distance of the mth train to the traction substation closest to the left, the distance of the mth train to the traction substation closest to the right, and the relative position of the mth train; Multiply the first parameter by the operation status information of the mth train and a preset proportionality coefficient to obtain the influence offset value corresponding to the mth train.

12. The system according to claim 7, wherein The controller is further configured to obtain the output power of the converter; when the slope of the output characteristic curve of the converter reaches the preset maximum limit slope and the output power of the converter reaches a preset threshold, control the converter of the traction substation closest to the nth traction substation to supplement and provide power.

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