Device for controlling number of operating main motors and method for controlling number of operating main motors

Abstract

Provided is technology that can control the switching of the number of operating main motors for railway vehicle travel, and thereby increase the efficiency of the main motor, prevent idling, and improve ride comfort. The present invention for solving the above problem is a device for controlling the number of operating main motors, wherein the device controls the number of operating main motors that generate power for the travel of a railway vehicle. The device comprises a plurality of number-in-operation selection models based on the number of operating main motors for each environmental state, selects a number-in-operation selection model on the basis of the environmental state and the current number of operating main motors, and outputs a command for the number of operating main motors from the selected number-in-operation selection model by using a torque command and a vehicle speed as inputs. The number-in-operation selection model may be a table model that determines the number of operating main motors at which the efficiency of the main motors is maximized according to the vehicle speed and the total torque of the main motors, or a function model that indicates the relationship between the vehicle speed and the total torque of the main motors.

Description

Control device for the number of operating traction motors and method for controlling the number of operating traction motors

[0001] The present invention relates to a control device for the number of operating main motors and a method for controlling the number of operating main motors.

[0002] Traditionally, in railway vehicles in motion, all of the multiple traction motors were always in operation. In such systems, for example, the main control unit would output torque command values ​​to multiple drive units (trum motors), adjusting the torque distribution required for the train set according to the weight of each railway vehicle (empty weight + loaded weight), thereby controlling the traction motors of each drive unit.

[0003] However, in recent years, from the perspective of energy saving, when the required torque is less than the maximum torque that multiple drive units can output, attempts have been made to operate the main motors at a high-efficiency point by reducing the number of operating main motors.

[0004] For example, Patent Document 1 discloses a technology for controlling the number of operating main motors in a railway vehicle control device by calculating highly efficient operating conditions based on efficiency data of drive units stored in a memory device.

[0005] Furthermore, Patent Document 2 discloses a technology for determining the number of main motors to be operated in a railway vehicle based on the current speed and the torque currently required, and for equally distributing the torque to the determined number of main motors.

[0006] Japanese Patent Publication No. 2018-57185, International Publication No. 2019 / 107016

[0007] However, the technology disclosed in Patent Document 1 suppresses the unnecessary switching of the number of operating main motors in conjunction with notch switching, but does not suppress the unnecessary switching of the number of operating main motors in conjunction with increases or decreases in torque commands caused by operating conditions such as the gradient of the line and the interaction between train cars. Therefore, there is a risk that the number of switching cycles of the number of operating main motors will increase during powering while running at a constant speed, making it unavoidable that the ride comfort will deteriorate and the efficiency of the main motors will decrease due to the transient operation of switching the number of operating motors.

[0008] Furthermore, the technology disclosed in Patent Document 2 may also result in an increased number of switching cycles for the number of operating traction motors depending on operating conditions such as the gradient of the line and the interaction between train cars. This raises concerns about deterioration of ride comfort and a decrease in the efficiency of the traction motors due to the transient operation of switching between operating motors.

[0009] Therefore, the present invention aims to provide a technology that can achieve high efficiency of the main motor, prevent wheel slippage, and improve ride comfort by controlling the switching of the number of operating main motors for railway vehicle operation.

[0010] To solve the above problems, one of the typical traction motor operating count control devices of the present invention includes multiple operating count selection models corresponding to the number of operating traction motors for each environmental condition, and selects an operating count selection model based on the environmental condition and the current number of operating traction motors, and outputs an operating count command for the traction motors from the selected operating count selection model, taking the torque command and vehicle speed as input.

[0011] According to the present invention, by controlling the switching of the number of operating main motors for railway vehicle operation, it is possible to provide a technology that can achieve high efficiency of the main motors, prevent wheel slippage, and improve ride comfort.

[0012] Other issues, configurations, and effects not mentioned above will be clarified by the description of the embodiments for carrying out the invention below.

[0013] Figure 1 shows an example of the configuration of a railway vehicle formation according to Example 1. Figure 2 shows an example of the configuration of a control device for a railway vehicle according to Example 1. Figure 3 shows an example of the configuration of the operating number selection model DB according to Example 1. Figure 4 shows an example of the operating number selection model according to Example 1, based on the currently operating number of main motors. Figure 5 shows an example of the processing flow of the operating number control unit according to Example 1. Figure 6 shows an example of the efficiency map of a main motor according to Example 1. Figure 7 shows an example of the efficiency list of main motors with respect to vehicle speed V and total torque T of the main motors according to Example 1. Figure 8 shows an example of the optimal number of main motors table according to Example 1. Figure 9 shows the relationship between the efficiency map of the main motors and the upper limit torque according to the environmental conditions according to Example 1. Figure 10 shows an example of the operating number selection model according to the environmental conditions according to Example 1. Figure 11 shows an example of the operating number selection model according to Example 2. Figure 12 shows an example of the configuration of the operating number selection model DB according to Example 3. Figure 13 shows an example of the operating number selection model according to Example 3. Figure 14 shows another example of the configuration of the operating unit selection model DB according to Embodiment 3. Figure 15 shows another example of the operating unit selection model according to Embodiment 3. Figure 16 shows an example of the configuration of the vehicle information control device according to Embodiment 4.

[0014] The embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to these embodiments. Furthermore, in the drawings, identical parts are denoted by the same reference numerals.

[0015] The examples provided are illustrative for explaining the present invention, and have been omitted and simplified as appropriate for clarity of explanation. Furthermore, not all of the elements and combinations thereof described in the examples are necessarily essential to the solution of the invention.

[0016] When there are multiple components with the same or similar function, they may be described using the same symbol but with different subscripts. Furthermore, if it is not necessary to distinguish between these multiple components, the subscripts may be omitted in the description.

[0017] The motor operation count control device of Embodiment 1 will be described with reference to Figures 1 to 10.

[0018] [Railway Vehicle Formation Configuration] Figure 1 is a diagram showing an example of the configuration of a railway vehicle formation according to Embodiment 1. As shown in Figure 1, the railway vehicle formation 1 in this example consists of multiple railway vehicles 2 (trailer cars 2T and motor cars 2M). The railway vehicle formation 1 may be configured by connecting a trailer car 2T equipped with a vehicle information control device 9, a motor car 2M, and a trailer car 2T without a vehicle information control device 9, or it may be configured in any other way.

[0019] In railway car formation 1, the motor car 2M is a vehicle equipped with a main motor 6, and the trailer car 2T is a vehicle not equipped with a main motor 6.

[0020] In this example, trailer car 2T is the leading vehicle and is equipped with a trailing axle 4, a driving control unit 8 located in the driver's cab, and a vehicle information control device 9.

[0021] The train operation control unit 8 has the function of outputting signals related to train operation. The vehicle information control device 9 has the function of receiving signals from the train operation control unit 8 and calculating output command values ​​for the electric motor car 2M to the railway vehicle control device 10, such as notch commands and torque commands.

[0022] The electric vehicle 2M is, for example, a powered vehicle and comprises a driving axle 5, a plurality of main motors 6 (6a, 6b, 6c, 6d) that transmit power to the driving axle 5 via gears (not shown), a power converter 7 consisting of an inverter with a VVVF (variable voltage variable frequency) control system that drives the plurality of main motors 6, a railway vehicle control device 10 that controls the power converter 7 in response to commands from a vehicle information control device 9, and a pantograph 3 as a current collector that supplies power to the power converter 7.

[0023] The power converter 7 has the function of controlling the inverter to adjust the current, voltage, and frequency supplied to the main motor 6 so that the required acceleration and braking forces can be obtained. The power converter 7 is supplied with current from the pantograph 3 via a high-speed circuit breaker, charging contactor, charging resistor, current breaker, filter reactor, filter capacitor, and earth brush (not shown).

[0024] The pantograph 3 may be provided in a configuration that is shared by multiple electric cars 2M. In that case, there will be electric cars 2M without a pantograph 3. Note that the power supply to the power converter 7 is not limited to the pantograph 3; for example, power may be supplied from a storage battery or a fuel cell.

[0025] The railway vehicle control device 10 has the function of controlling the inverter of the power converter 7 in response to notch commands and torque commands from the vehicle information control device 9.

[0026] Since each motor car 2M has a different torque to output depending on the load of the railway vehicle it is responsible for, the vehicle information control device 9 determines the torque from the respective load and transmits a torque command to each motor car 2M. However, this torque command may also be calculated by the railway vehicle control device 10. For example, the railway vehicle control device 10, upon receiving a constant speed running command from the vehicle information control device 9, can calculate the torque command using the target speed, vehicle speed, and load.

[0027] [Configuration of a railway vehicle control device] Figure 2 is a diagram showing an example of the configuration of a railway vehicle control device according to Embodiment 1. As shown in Figure 2, the railway vehicle control device 10 of this embodiment is configured to include an operating unit control unit 11 and a torque command generation unit 13.

[0028] The operating unit count control unit 11 includes an operating unit count selection model DB 12. The operating unit count selection model DB 12 stores multiple operating unit count selection models. Details of the operating unit count selection models will be described later.

[0029] When the operating motor count control unit 11 receives the current operating motor count X(t), which is the number of main motors operating at the current time t, and environmental conditions (for example, occupancy rate (or load-sensitive) or adhesion coefficient), an operating motor count selection model corresponding to the input is selected from the operating motor count selection model DB 12. Taking the vehicle speed V and torque command T as inputs, the operating motor count command X(t+Δt) is output from the selected operating motor count selection model. Here, Δt is the elapsed time required to determine the next operating motor count. This is usually the calculation cycle of the vehicle information control device 9, and is expected to be between microseconds and several seconds. The operating motor count command X(t+Δt) commands the number of main motors operating at time t+Δt, after time Δt has elapsed from the current time t.

[0030] In the following explanation, the occupancy rate and adhesion coefficient of a railway vehicle are used as examples of environmental conditions, but the occupancy rate may be replaced with the load-bearing capacity of the railway vehicle.

[0031] [Configuration of the Operating Unit Count Selection Model DB] Figure 3 shows an example of the configuration of the operating unit count selection model DB according to Embodiment 1. The operating unit count selection model DB 12 stores operating unit count selection models for each environmental condition (occupancy rate and adhesion coefficient), and each operating unit count selection model has multiple models set according to the currently operating number of main motors X(t). Hereinafter, the operating unit count selection model set according to the currently operating number of main motors X(t) will be simply referred to as a "model".

[0032] For example, the operating unit selection model 12a is a model for when the environmental conditions are a 200% occupancy rate and a 20% adhesion coefficient. In this example, the operating unit selection model 12a has four settings: model 12a1, model 12a2, model 12a3, and model 12a4, depending on the possible number of currently operating main motors X(t) from 0 to 4.

[0033] Similarly, the operating unit selection model 12b is a model for when the environmental conditions are a 200% occupancy rate and a 15% adhesion coefficient, the operating unit selection model 12c is a model for when the environmental conditions are a 150% occupancy rate and a 20% adhesion coefficient, and the operating unit selection model 12d is a model for when the environmental conditions are a 150% occupancy rate and a 15% adhesion coefficient. Each of the operating unit selection models has four models set up depending on the possible number of currently operating main motors X(t) from 0 to 4.

[0034] In Example 1, the number of currently operating main motors X(t) is set to a range of 0 to 4, but it is not limited to this range and can be set according to the number of main motors mounted on the 2M motor vehicle.

[0035] [Operating Unit Selection Model Based on the Currently Operating Number of Main Motors] Figure 4 is a diagram showing an example of an operating unit selection model based on the currently operating number of main motors according to Embodiment 1. The configuration of the operating unit selection model will be explained below using operating unit selection model 12a as an example, where the environmental conditions are a 200% occupancy rate and a 20% adhesion coefficient. However, the basic configuration is the same for operating unit selection models 12b, 12c, and 12d, which are models for different environmental conditions.

[0036] As described above, the operating unit selection model 12a is a model for when the environmental conditions are a 200% occupancy rate and a 20% adhesion coefficient. In this example, models 12a1, 12a2, 12a3, and 12a4 are set according to the currently operating number of main motors X(t).

[0037] Model 12a1 is the model referred to when there are 0 or 1 motors in operation in the motor vehicle 2M, that is, when the number of currently operating main motors X(t) = 0 or 1. Similarly, Model 12a2 is the model referred to when there are 2 motors in operation, that is, when the number of currently operating main motors X(t) = 2, Model 12a3 is the model referred to when there are 3 motors in operation, that is, when the number of currently operating main motors X(t) = 3, and Model 12a4 is the model referred to when there are 4 motors in operation, that is, when the number of currently operating main motors X(t) = 4.

[0038] Models 12a1 to 12a4 can all determine the number of operating main motors command X(t+Δt) according to the vehicle speed V and torque command T (total torque T of the main motors). The number of operating main motors command X(t+Δt) determined by models 12a1 to 12a4 is the number of operating main motors that achieves the highest operating efficiency under the conditions for which each model is selected.

[0039] In Model 12a1, Ta1_12 represents the boundary between the region where X(t+Δt)=1 and the region where X(t+Δt)=2. Similarly, Ta1_23 represents the boundary between the region where X(t+Δt)=2 and the region where X(t+Δt)=3, and Ta1_34 represents the boundary between the region where X(t+Δt)=3 and the region where X(t+Δt)=4.

[0040] In Model 12a2, Ta2_23 and Ta2_34 are identical to Ta1_23 and Ta1_34 in Model 12a1, respectively. On the other hand, Ta2_12 in Model 12a2 is the boundary of Ta1_12 in Model 12a1, shifted downward by a certain torque.

[0041] In Model 12a3, Ta3_12 and Ta3_34 are identical to Ta1_12 and Ta1_34 in Model 12a1, respectively. On the other hand, Ta3_23 in Model 12a3 is the boundary that is shifted downward by a certain torque from Ta1_23 in Model 12a1 (= Ta2_23 in Model 12a2).

[0042] In Model 12a4, Ta4_12 and Ta4_34 are identical to Ta1_12 and Ta1_23 in Model 12a1, respectively. On the other hand, Ta4_34 in Model 12a4 is the boundary of Ta1_34 in Model 12a1 (= Ta3_34 in Model 12a3) shifted downward by a certain torque.

[0043] By shifting the boundaries in this way for each model, frequent switching of the main motor can be suppressed.

[0044] For example, as described above, by setting Ta2_12 to be lower than Ta1_12, the total torque of the main motors switched to X(t+Δt)=1 in Model 12a2 (currently operating number of main motors X(t)=2) becomes smaller than the total torque of the main motors switched to X(t+Δt)=2 in Model 12a1 (currently operating number of main motors X(t)=1). As a result, the switching that reduces the number of operating main motors from two to one is suppressed.

[0045] Similarly, as described above, by setting Ta3_23 to be lower than Ta2_23, the total torque of the main motors switched to X(t+Δt)=2 in Model 12a3 (currently operating number of main motors X(t)=3) becomes smaller than the total torque of the main motors switched to X(t+Δt)=3 in Model 12a2 (currently operating number of main motors X(t)=2). As a result, the switching that reduces the number of operating main motors from three to two is suppressed.

[0046] Furthermore, as described above, by setting Ta4_34 to be lower than Ta3_34, the torque of the main motors switched to X(t+Δt)=3 in Model 12a4 (currently operating number of main motors X(t)=4) becomes smaller than the total torque of the main motors switched to X(t+Δt)=4 in Model 12a3 (currently operating number of main motors X(t)=3). As a result, the switching that reduces the number of operating main motors from four to three is suppressed.

[0047] In Example 1, even if a command to temporarily reduce the total torque of the main motors is issued after the number of operating main motors has been increased, the number of operating motors will not be immediately reduced, thus avoiding frequent switching of the number of operating motors. Similarly, even if a command to temporarily increase the total torque of the main motors is issued after the number of operating main motors has been reduced, the number of operating motors will not be immediately increased, thus again avoiding frequent switching of the number of operating motors.

[0048] In the above explanation, we showed an example where the torque at the boundary between the region X(t+Δt)=X and the region X(t+Δt)=X+1 in the model with X+1 currently operating main motors is set to be a constant torque smaller regardless of speed than the torque at the boundary between the region X(t+Δt)=X and the region X(t+Δt)=X+1 in the model with X currently operating main motors. However, this is not the only example, and for example, the amount of torque shift may be changed for each speed. It is also possible to change the amount of torque shift for each model.

[0049] [Processing Flow of the Operating Unit Control Unit] Figure 5 shows an example of the processing flow of the operating unit control unit according to Embodiment 1. The processing flow of the operating unit control unit 11 consists of the following five steps (steps S11 to S15).

[0050] In step S11, the operating motor count control unit 11 determines whether the operating motor count control for the main motors is ON or OFF. The conditions for turning the operating motor count control for the main motors ON / OFF can be set as appropriate. For example, it can be set ON when the railway vehicle is in constant speed running mode, and OFF when it is in acceleration mode from a standstill, as all four main motors are naturally in full operation. If the answer in step S11 is Yes, the process proceeds to step S12. On the other hand, if the answer in step S11 is No, the process proceeds to step S15.

[0051] In step S12, the operating unit control unit 11 reads the torque command T, vehicle speed V, environmental conditions, and the number of currently operating main motors X(t), and proceeds to steps S13 and S14.

[0052] In step S13, the operating unit control unit 11 selects an operating unit selection model from the operating unit selection model DB12 according to the environmental conditions and the currently operating number of main motors X(t).

[0053] In step S14, the operating number control unit 11 inputs the torque command T and the vehicle speed V read in step S12 into the operating number selection model selected in step S13, and determines the operating main motor number command X(t + Δt). The determined operating main motor number command X(t + Δt) is output to the torque command generation unit 13, and the process proceeds to step S15. When the torque command T is 0, the operating main motor number command X(t + Δt) = 0.

[0054] In step S15, the operating number control unit 11 advances the time t to the time t + Δt and ends the process.

[0055] [Creation of Operating Number Selection Model] Next, referring to FIGS. 6 to 8, taking the case where the current operating main motor number X(t) = 1 as an example, the creation of the operating number selection model in a predetermined environmental state will be described.

[0056] FIG. 6 is a diagram showing an example of the efficiency map of the main motor according to the first embodiment. FIG. 6(a) shows the relationship between the vehicle speed V (horizontal axis) and the torque τ per main motor (vertical axis) of the main motor in an efficiency map (contour map). In this example, although the efficiency of the main motor is map-displayed in FIG. 6(a), instead of the efficiency of the main motor, the efficiency of a railway vehicle including at least one of an inverter, a gear, and a filter reactor may be map-displayed.

[0057] In FIG. 6(a), η ｊ , ｉ , η Ｂ , η Ｃ , η Ｄ are the points where the efficiency of the main motor is equal, and show an example of the contour lines in the contour map. The contour lines η Ａ , η Ｂ , η Ｃ , η Ｄ become higher efficiency towards the center side (the upper right side in FIG. 6(a)).

[0058] According to the efficiency map of the main motor in FIG. 6(a), when the vehicle speed V and the total torque Τ of the main motor are given to the operating number control unit 11, the efficiency per main motor can be obtained. For example, the vehicle speed V ｊ and the total torque Τ of the main motor ｉWhen the number of operating units is given to the operating unit control unit 11, η ｉｊ＿１ This is the efficiency of the main motor when one main motor is in operation, and η ｉｊ＿２ This is the efficiency per main motor when two main motors are operating, and η ｉｊ＿３ This is the efficiency per main motor when three main motors are operating, and η ｉｊ＿４ This represents the efficiency per main motor when four main motors are in operation.

[0059] Figure 7 shows an example of a list of the efficiency of the main motors with respect to the vehicle speed V and the total torque T of the main motors according to Embodiment 1. Figure 7(a) shows the efficiency list when one main motor is operating (X=1), Figure 7(b) shows the efficiency list when two main motors are operating (X=2), Figure 7(c) shows the efficiency list when three main motors are operating (X=3), and Figure 7(d) shows the efficiency list when four main motors are operating (X=4).

[0060] The shaded areas in Figures 7(a) to 7(d) represent the vehicle speed V shown in Figure 6(a). ｊ Furthermore, the total torque T of the main motor ｉ Efficiency of the main motor at that time η ｉｊ This shows, for example, from Figure 7(a), the vehicle speed V ｊ Furthermore, the total torque T of the main motor ｉ When one main motor is operating, the efficiency is η ｉｊ＿１ That is the case.

[0061] Furthermore, if the number of operating units X is reduced, the operating point of T / X (total torque T of the main motors divided by the number of operating units X) and the vehicle speed V may fall outside the range of the efficiency map in Figure 6(a). Figure 6(b) illustrates such a case. Total torque T of the main motors ｋ If the value is so large that it falls outside the range of the efficiency map, it is outside the operating range of the main motor, for example, the efficiency η ｋｊ＿１ By setting this to 0%, we prevent X, which falls outside the range of the efficiency map in Figure 8 (described later), from being selected.

[0062] Figure 8 shows an example of an optimal number of main motors table according to Embodiment 1. Figure 8 is an optimal number of main motors table when the currently operating number of main motors X(t) = 1, where X in the table is the optimal number of operating main motors given the total torque T of the main motors and the vehicle speed V. For example, the total torque T of the main motors ｊ and vehicle speed V ｉ Given the number of operating units X ｉｊ This is η in Figure 7. ｉｊ＿１ η ｉｊ＿２ η ｉｊ＿３ η ｉｊ＿４ It is calculated as follows using [the formula].

[0063] max(η) ｉｊ＿１ η ｉｊ＿２ η ｉｊ＿３ η ｉｊ＿４ ) = η ｉｊ＿１ At that time, X ｉｊ = 1 max(η) ｉｊ＿１ η ｉｊ＿２ η ｉｊ＿３ η ｉｊ＿４ ) = η ｉｊ＿２ At that time, X ｉｊ = 2 max(η) ｉｊ＿１ η ｉｊ＿２ η ｉｊ＿３ η ｉｊ＿４ ) = η ｉｊ＿３ At that time, X ｉｊ = 3 max(η) ｉｊ＿１ η ｉｊ＿２ η ｉｊ＿３ η ｉｊ＿４ ) = η ｉｊ＿４ At that time, X ｉｊ =4. Furthermore, if the total torque T of the main motors given by the torque command T is 0, it is optimal to output a total torque T=0 by setting the torque of all main motors to 0, so the optimal number of operating units X is 0.

[0064] Figure 8 shows the optimal number of units, based on the total torque T of the main motors. ｉ and vehicle speed V ｊ to T １ ~T Ｌ and V １ ~V Ｍ This can be obtained by changing the value within the specified range and performing the above calculation.

[0065] To make the operating unit selection model take the form of Model 12a1 in Figure 4, the total torque T of the main motors in Figure 8 １ ~T Ｌ and vehicle speed V １ ~V Ｍ You just need to set it up in detail.

[0066] Once Model 12a1 in Figure 4 is created, Models 12a2 to 12a4 are created based on this, corresponding to the current number of operating main motors X(t). Specifically, Models 12a2 to 12a4 are created by adjusting the boundary between the optimal number of operating motors X and X+1 (total torque of the main motors) in Model 12a1.

[0067] In other words, in Model 12a2, the boundary Ta2_12 between the region X(t+Δt)=1 and the region X(t+Δt)=2 is set to be smaller than the predetermined torque of Ta1_12 in Model 12a1. By setting Ta2_12 in this way, even if the total torque of the main motors decreases within the predetermined torque range after the reference to Model 12a2 begins due to an increase in the total torque of the main motors as X(t+Δt) changes from 1 to 2 while referencing Model 12a1, the number of operating motors will not return from 2 to 1. This avoids frequent switching of the number of operating motors between X(t)=1 and X(t)=2.

[0068] Similarly, in Model 12a3, the boundary Ta3_23 between the region X(t+Δt)=2 and the region X(t+Δt)=3 is set to a predetermined torque smaller than Ta1_23 in Model 12a1 (= Ta2_23 in Model 12a2). By setting Ta3_23 in this way, even if the total torque of the main motors decreases within the predetermined torque range after the reference to Model 12a3 begins due to an increase in the total torque of the main motors, the number of operating motors will not revert from 3 to 2. This avoids frequent switching of the number of operating motors between X(t)=2 and X(t)=3.

[0069] Furthermore, in Model 12a4, the boundary Ta4_34 between the region X(t+Δt)=3 and the region X(t+Δt)=4 is set to have a predetermined torque smaller than Ta1_34 in Model 12a1 (= Ta3_34 in Model 12a3). By setting Ta4_34 in this way, even if the total torque of the main motors decreases within the predetermined torque range after the reference to Model 12a4 begins due to an increase in the total torque of the main motors while referencing Model 12a3, the number of operating motors will not revert from 4 to 3. This avoids frequent switching of the number of operating motors between X(t)=3 and X(t)=4.

[0070] As described above, by providing a model for selecting the number of operating main motors according to the currently operating number of main motors X(t), frequent switching of the number of operating main motors can be avoided, preventing deterioration of ride comfort and avoiding efficiency reduction associated with the transient operation of frequent switching of the number of operating main motors.

[0071] [Model for selecting the number of operating units according to environmental conditions] Next, referring to Figures 9 and 10, we will explain a model for selecting the number of operating units according to environmental conditions (occupancy rate and adhesion coefficient), using the case where the current number of operating main motors X(t) = 1 as an example.

[0072] Figure 9 is a diagram showing the relationship between the efficiency map of the main motor according to Embodiment 1 and the upper limit torque according to the environmental conditions. The efficiency map shown in Figure 9 is the same as the efficiency map in Figure 6, and η Ａ η Ｂ η Ｃ η Ｄ These are contour lines connecting points where the efficiency of the main motors is equal.

[0073] Generally, when the occupancy rate of a railway vehicle is low, the torque per traction motor required to prevent wheel slip (upper torque limit) decreases. As shown in Figure 9, for example, the upper torque τ for an occupancy rate of 200% and a adhesion coefficient of 20% ２００＿２０ In comparison, the upper limit torque τ with a load factor of 150% and a adhesion coefficient of 20% １５０＿２０ It becomes smaller.

[0074] Furthermore, when the friction of the wheels or rails is low due to reasons such as rain, the torque per main motor to prevent slippage must be set low. As shown in Figure 9, for example, the upper limit torque τ for a load of 150% and a coefficient of adhesion of 20% １５０＿２０ In comparison, the upper limit torque τ with a load factor of 150% and a adhesion coefficient of 15% １５０＿１５ It becomes smaller.

[0075] Figure 10 shows an example of a model for selecting the number of operating units according to environmental conditions, according to Embodiment 1. The operating unit selection model 12_1 shown in Figure 10 is a model for the case where the number of currently operating main motors X(t) = 1. Models 12a1, 12b1, 12c1, and 12d1 are created by limiting the torque per main motor according to environmental conditions as shown in Figure 9, and then following the same procedure as shown in Figures 6 to 8.

[0076] Next, we will describe each model in Figure 10. Model 12a1, even taking into account the constraints in Figure 9, has Ta1_12 < τ ２００＿２０ , Ta1_23<2×τ ２００＿２０ , Ta1_34<3×τ ２００＿２０ Since this condition is met, it is not affected by the upper torque limit.

[0077] In contrast, in model 12b1, where the coefficient of adhesion is smaller than that of model 12a1, considering the limitations in Figure 9, τ ２００＿１５ Since <Tb1_12, the total torque T of the main motor at the boundary Tb1_12 between the region X(t+Δt)=1 and the region X(t+Δt)=2 is limited compared to model 12a1. This is because the total torque T of the main motor is limited to τ ２００＿１５ Below this value, the efficiency when X(t+Δt)=1 falls outside the operating range due to the constraint of preventing wheel slippage, meaning that the operating range for X(t+Δt)=1 is narrowed.

[0078] Similarly, in model 12c1, where the occupancy rate is lower than in model 12a1, taking into consideration the limitations in Figure 9, τ １５０＿１５Since <Tc1_12, the total torque T of the main motor at the boundary Tc1_12 between the region X(t+Δt)=1 and the region X(t+Δt)=2 is limited compared to Model 12a1. This is because the total torque T of the main motor is limited to τ １５０＿２０ Below this value, the efficiency when X(t+Δt)=1 falls outside the operating range due to the constraint of preventing wheel slippage, meaning that the operating range for X(t+Δt)=1 is narrowed.

[0079] Furthermore, in model 12d1, where both the occupancy rate and the adhesion coefficient are smaller compared to model 12a1, considering the limitations in Figure 9, τ １５０＿１５ <Td1_12 and 2×τ １５０＿１５ Since <Td1_23, the total torque T of the main motor at the boundary Td1_12 between the region X(t+Δt)=1 and the region X(t+Δt)=2, and the total torque T of the main motor at the boundary Td1_23 between the region X(t+Δt)=2 and the region X(t+Δt)=3, are limited compared to Model 12a1. This is because the total torque T of the main motor is τ １５０＿１５ Below this value, the efficiency when X(t+Δt)=1 falls outside the operating range due to the constraint of preventing wheel slippage, thus narrowing the operating range for X(t+Δt)=1, and the total torque T of the main motor is 2×τ １５０＿１５ Below this value, the efficiency when X(t+Δt)=2 falls outside the operating range due to the constraint of preventing wheel slippage, which means that the operating range for X(t+Δt)=2 is also narrowed.

[0080] By creating a model that selects the number of operating units according to environmental conditions, it becomes possible to control railway vehicles in a way that is more in line with the environmental conditions in which they operate.

[0081] The timing for updating the occupancy rate (load-sensitive) among the environmental conditions is optional. For example, since the vehicle weight changes due to passengers getting on and off, the occupancy rate may be updated after the vehicle doors close (after passengers get on and off at a station).

[0082] Also, regarding the update timing of the adhesion coefficient, since the adhesion coefficient is related to the track conditions, it may be updated at the timing when various sensors (such as cameras) installed in the vehicle or information regarding the track is obtained from outside the vehicle through wired communication or wireless communication.

[0083] Embodiment 2 sets the operating unit number selection model by a mathematical formula (function). While the operating unit number selection model of Embodiment 1 is a so-called table model, the operating unit number selection model of Embodiment 2 is a function model.

[0084] In Embodiment 1, the operating unit number selection model is a table model (table data) representing the relationship between the vehicle speed V and the operating main motor number command X(t + Δt) with respect to the total torque Τ of the main motors, and it is necessary to prepare numbers corresponding to the environmental conditions and the current operating main motor number X(t). The table model (table data) representing the relationship between the vehicle speed V and the operating main motor number command X(t + Δt) with respect to the total torque Τ of the main motors generally has a large data capacity, and a large-capacity storage device is required for implementation.

[0085] The operating unit number selection model of Embodiment 2 suppresses an increase in data capacity by adopting a function model.

[0086] FIG. 11 is a diagram showing an example of the operating unit number selection model according to Embodiment 2. The operating unit number selection model in FIG. 11 is an example in which the boundaries Tb1_12, Tb1_23, and Tb1_34 in the model 12b1 (boarding rate 200%, adhesion coefficient 15%) in FIG. 10 are set by a function model (approximate formula).

[0087] As shown in FIG. 11, for example, the boundary Tb1_12 is set by three function models (approximate formulas) according to the range of the vehicle speed V. That is, when the vehicle speed V is in the range of "0 ≦ V < 30", the approximate formula is "T = aV ０．５ + bV + cV ２ + d, provided that a = a ｂ１＿１２＿１ 、b = b ｂ１＿１２＿１ 、c = c ｂ１＿１２＿１ 、d = d ｂ１＿１２＿１ ". Also, when the vehicle speed V is in the range of "30 ≦ V < 50", the approximate formula is "T = aV ０．５ + bV + cV ２+d, provided that a = 0, b = 0, c = 0, d = τ ２００＿１５ ". Further, when the vehicle speed V is in the range of "50 ≤ V ≤ 120", the approximation formula is "T = aV ０．５ + bV + cV ２ + d, provided that a = a ｂ１＿１２＿３ , b = b ｂ１＿１２＿３ , c = c ｂ１＿１２＿３ , d = d ｂ１＿１２＿３ ".

[0088] The approximation formula in FIG. 11 is an example, and any approximation formula may be used as long as it can represent the boundary of the operating main motor number command X(t + Δt) from the relationship between the total torque Τ of the main motor and the vehicle speed V.

[0089] The coefficients of the approximation formula are set for each of a plurality of conditions (combinations of condition 1 and condition 2). As described above, for example, in Tb1_12, the coefficients of the approximation formula are determined for each of the conditions where the vehicle speed V is "0 ≤ V < 30", "30 ≤ V < 50", and "50 ≤ V ≤ 120". Note that optimization methods such as the least squares method can be used to determine the coefficients of the approximation formula.

[0090] In the second embodiment, for example, the operating number control unit 11 referring to the model 12b1 compares the total torque Τ of the main motor given by the torque command T with TA calculated from the approximation formula of Tb1_12 using the vehicle speed V, TB calculated from the approximation formula of Tb1_23 using the vehicle speed V, and TC calculated from the approximation formula of Tb1_34 using the vehicle speed V, to determine whether the operating main motor number command X(t + Δt) is any one of 1 to 4.

[0091] For example, when the total torque Τ of the main motor given by the torque command T is smaller than TA calculated from the approximation formula of Tb1_12 using the vehicle speed V, the operating main motor number command X(t + Δt) is 1.

[0092] In the second embodiment, by adopting a function model as the operating number selection model, it is not necessary to mount a large-capacity storage device.

[0093] Example 3 limits the number of operating unit selection models. In Example 1, the number of operating unit selection models is set on the condition that all of the main motors (maximum number of controls) installed on the electric vehicle 2M can be operated, whereas in Example 3, the number of operating unit selection models is set on the condition that only a portion of the total number of main motors installed on the electric vehicle 2M can be operated.

[0094] In other words, the operating unit selection model of Example 1 assumes that the main motors are operated in a range from one to a maximum of four. However, generally, when the total torque required for the main motors is small during constant-speed driving, operating four main motors reduces the torque per main motor, resulting in a significant decrease in efficiency.

[0095] The operational number selection model of Example 3 aims to improve the efficiency of the main motors by limiting the range of operational main motors to a range such as "1 or 4" or "2 or 4" rather than setting it to an arbitrary number from 1 to 4, thereby ensuring that the torque per main motor does not decrease even when the total torque of the main motors is small.

[0096] Referring to Figures 12 and 13, we will explain the operating unit selection model when the operating unit condition is limited to "1 unit or 4 units". Note that the creation of the operating unit selection model is the same as in Example 1, so the explanation will be omitted.

[0097] Figure 12 shows an example of the configuration of the operating unit selection model DB according to Embodiment 3. As shown in Figure 12, the operating unit selection model DB 12 in this embodiment stores, similar to Embodiment 1, models such as model 12a corresponding to an occupancy rate of 200% and an adhesion coefficient of 20%, model 12b corresponding to an occupancy rate of 200% and an adhesion coefficient of 15%, model 12c corresponding to an occupancy rate of 150% and an adhesion coefficient of 20%, and model 12d corresponding to an occupancy rate of 150% and an adhesion coefficient of 15% as environmental conditions.

[0098] However, in Example 3, for each model, only two models are set: one for the case where the number of currently operating main motors X(t) = 0 or 1, and another for the case where the number of currently operating main motors X(t) = 4.

[0099] Figure 13 shows an example of an operational number selection model according to Embodiment 3. For example, if there are 0 or 1 motors in operation in motor vehicle 2M, that is, if the current number of operational main motors X(t) = 0 or 1, model 12a1b is referred to. Similarly, if there are 4 motors in operation, that is, if the current number of operational main motors X(t) = 4, model 12a4b is referred to.

[0100] In model 12a1b, Ta1_14b represents the boundary between the region where X(t+Δt)=1 and the region where X(t+Δt)=4.

[0101] Furthermore, in model 12a4b, Ta4_14b represents the boundary between the region X(t+Δt)=1 and the region X(t+Δt)=4. However, Ta4_14b is the boundary obtained by shifting Ta1_14b of model 12a1b downward by a certain torque, similar to Ta2_12 in model 12a2 in Figure 4.

[0102] Next, with reference to Figures 14 and 15, we will explain the operating unit selection model when the operating unit condition is limited to "2 units or 4 units".

[0103] Figure 14 shows another example of the configuration of the operating unit selection model DB according to Example 3. As shown in Figure 14, the operating unit selection model DB 12 in this example, like Example 1, stores models such as model 12a corresponding to an occupancy rate of 200% and a adhesion coefficient of 20%, model 12b corresponding to an occupancy rate of 200% and a adhesion coefficient of 15%, model 12c corresponding to an occupancy rate of 150% and a adhesion coefficient of 20%, and model 12d corresponding to an occupancy rate of 150% and a adhesion coefficient of 15% as environmental conditions. However, for each model, only two models are set: one for the case where the current number of operating main motors X(t) = 0 or 2, and another for the case where the current number of operating main motors X(t) = 4.

[0104] Figure 15 shows another example of the operating number selection model according to Embodiment 3. For example, if there are 0 or 2 motors in operation in electric vehicle 2M, that is, if the current number of operating main motors X(t) = 0 or 2, model 12a2c is referred to. Similarly, if there are 4 motors in operation, that is, if the current number of operating main motors X(t) = 4, model 12a4c is referred to.

[0105] In Model 12a2c, Ta2_24c represents the boundary between the region X(t+Δt)=2 and the region X(t+Δt)=4.

[0106] Furthermore, in model 12a4c, Ta4_24c represents the boundary between the region X(t+Δt)=2 and the region X(t+Δt)=4. However, Ta4_24c is the boundary obtained by shifting Ta2_24c of model 12a2c downward by a certain torque, similar to Ta3_23 in model 12a3 in Figure 4.

[0107] In Example 3, the data capacity of the storage device to be implemented can be reduced by reducing the number of boundaries in the operating unit selection model.

[0108] Embodiment 4 involves mounting the operating unit count control unit 11 on the vehicle information control device 9. In Embodiment 1, the operating unit count control unit 11 is mounted on a railway vehicle control device 10 provided for each motor car 2M, whereas in Embodiment 4, the operating unit count control unit 11 is mounted on a vehicle information control device 9 provided, for example, on the leading vehicle.

[0109] Figure 16 shows an example of the configuration of a vehicle information control device according to Embodiment 4. As shown in Figure 16, the operating unit control unit 11 in this embodiment is mounted on the vehicle information control device 9 and controls the number of operating main motors of all electric vehicles 2M in a unified manner.

[0110] The basic functions of the operating unit count control unit 11 in Embodiment 4 are the same as in Embodiment 1. In Embodiment 4 as well, the operating unit count control unit 11 is equipped with an operating unit count selection model DB 12. When the current number of operating main motors X(t), vehicle speed V, environmental conditions (e.g., occupancy rate and adhesion coefficient) and torque command T are read, the operating unit count selection model is selected from the operating unit count selection model DB 12 according to the current number of operating main motors X(t) and environmental conditions. The torque command T and vehicle speed V are inputs, and the operating unit count command X(t+Δt) is output to the torque command generation unit 13 from the selected operating unit count selection model.

[0111] In Embodiment 4, by reducing the number of operating unit control units 11, it is possible to reduce the memory capacity and computational load of the railway vehicle control device 10.

[0112] Furthermore, in Embodiment 4, it is possible to broaden the range of control over the number of operating main motors. For example, assuming a railway train set with four motor cars (2M) and each motor car equipped with four main motors, the total number of main motors in the railway train set 1 is 16, and the number of main motors controlled by the railway vehicle control device 10 for each motor car (2M) can range from 0 to 4.

[0113] In Embodiment 1, the operating unit control unit 11 is mounted on the railway vehicle control device 10 of each motor car 2M, so the number of main motors is controlled in the range of 0 to 4. In contrast, in Embodiment 4, the operating unit control unit 11 can control the main motors of all motor cars 2M in the range of 0 to 16. This makes it possible to control the system in a way that stops all the main motors of a particular motor car 2M, for example, to prevent wheel slippage.

[0114] [Examples of modifications] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the present invention.

[0115] For example, the total torque T of the main motors in the operating number selection model shown in Figure 4 of Example 1 can also be used to create a similar operating number selection model if it represents the total regenerative torque of the main motors. Specifically, an operating number selection model for powering can be created based on the efficiency map of the powering main motors, and an operating number selection model for regeneration can be created from the efficiency map of the regenerative main motors. By having both operating number selection models, an operating number command X(t+Δt) can be output by selecting either the operating number selection model for powering or the operating number selection model for regeneration depending on whether the total torque is powering or regenerating.

[0116] Furthermore, in Example 1 and other examples, although the number of operating main motors is specified based on the command X(t+Δt), it is not specified which inverter (main motor) to operate. This can be done by rotating the main motors so that their operating frequency or temperature is leveled out. This makes it possible to equalize the deterioration of the inverters and main motors.

[0117] 1: Railway vehicle formation, 2: Railway vehicle (2T: Trailer car, 2M: Motor car), 3: Pantograph, 4: Trailer axle, 5: Drive axle, 6 (6a, 6b, 6c, 6d): Main motor, 7: Power converter, 8: Operation control unit, 9: Vehicle information control device, 10: Control device for railway vehicles, 11: Number of operating units control unit (Number of operating units control device), 12: Number of operating units selection model DB, 13: Torque command generation unit

Claims

1. A traction motor operation count control device for controlling the number of traction motors in operation that generate power for the running of a railway vehicle, comprising a plurality of operation count selection models corresponding to the number of traction motors in operation for each environmental condition, selecting an operation count selection model based on the environmental condition and the current number of traction motors in operation, and outputting an operation count command for the traction motors from the selected operation count selection model, taking a torque command and vehicle speed as input.

2. A traction motor operating count control device according to claim 1, characterized in that the environmental conditions include at least the occupancy rate or load of the railway vehicle and the adhesion coefficient of the railway vehicle.

3. A traction motor operating number control device according to claim 1, wherein each operating number selection model is a table model that determines the number of traction motors operating that maximizes the efficiency of the traction motors according to the vehicle speed and the total torque of the traction motors, and the operating number selection model includes, among the operating number selection models, a first operating number selection model for when the number of operating traction motors is M and a second operating number selection model for when the number of operating traction motors is N (M < N), which correspond to the same environmental conditions, and the total torque of the traction motors that indicates the boundary between the region where the number of operating traction motors that maximizes the efficiency of the traction motors is M and the region where the number of operating traction motors is N are different from each other.

4. A traction motor operating count control device according to claim 3, characterized in that, when comparing the total torques of the different traction motors at the same vehicle speed, the total torque of the traction motors indicating the boundary in the second operating count selection model is smaller than the total torque of the traction motors indicating the boundary in the first operating count selection model.

5. A traction motor operating number control device according to claim 1, wherein each operating number selection model is a function model showing the relationship between the vehicle speed and the total torque of the traction motors, the function model showing the boundary between the number of traction motors operating that maximizes the efficiency of the traction motors, and the operating number selection model includes, among the operating number selection models, a third operating number selection model for when the number of traction motors operating is M and a fourth operating number selection model for when the number of traction motors operating is N (M < N), which correspond to the same environmental conditions, and the function models showing the boundary between the number of operating motors M that maximizes the efficiency of the traction motors and the number of operating motors N are different from each other.

6. A traction motor operating count control device according to claim 5, characterized in that, when compared at the same vehicle speed, the total torque of the traction motors shown by the function model in the fourth operating count selection model is smaller than the total torque of the traction motors shown by the function model in the third operating count selection model.

7. A traction motor operating count control device according to any one of claims 1 to 6, characterized in that the plurality of operating count selection models correspond to a portion of the total number of traction motors mounted on the railway vehicle.

8. A traction motor operating count control device according to any one of claims 1 to 6, characterized in that the plurality of operating count selection models correspond to the total number of traction motors installed in the railway vehicle.

9. A method for controlling the number of operating traction motors for generating power for the operation of a railway vehicle, comprising: a plurality of operating number selection models corresponding to the number of operating traction motors for each environmental condition; selecting an operating number selection model based on the environmental condition and the current number of operating traction motors; and outputting an operating number command for the traction motors from the selected operating number selection model, with torque command and vehicle speed as input.

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