Motor control device and railway vehicle driving system

Abstract

This motor control device (11) of the present invention is mounted to a railway vehicle and integrally controls a plurality of propulsion motors (3a, 3b) that apply a driving force to the railway vehicle and another railway vehicle being towed by the railway vehicle. The railway vehicle comprises: continuously variable transmission systems (26a, 26b) that are interposed between the propulsion motors (3a, 3b) and wheel axles (20a, 20b) of the railway vehicle and are configured to be able to continuously change a transmission gear ratio that is the ratio of the motor speed that is the rotation speed of the propulsion motors (3a, 3b), with respect to the wheel speed that is the speed of the wheels (6a, 6b) coupled by the wheel axles (20a, 20b). The motor control device (11) implements first control for adjusting the transmission gear ratio to be instructed to the continuously variable transmission systems (26a, 26b) on the basis of wheel diameter information that is information on the length in the radial direction of the plurality of wheels (6a, 6b).

Description

Motor control device and railway vehicle drive system

[0001] The present disclosure relates to a motor control device that collectively controls multiple propulsion motors mounted on a railway vehicle, and a railway vehicle drive system that includes the motor control device.

[0002] Conventionally, in railway vehicle drive systems, a motor control device has been used to collectively control multiple propulsion motors in units of two or four. Compared to the individual control method in which one control device controls each propulsion motor individually, the centralized method of collectively controlling multiple propulsion motors allows for a significant reduction in the weight and volume of the control device, thereby enabling a significant reduction in vehicle weight.

[0003] When multiple propulsion motors are controlled in a centralized manner, the same frequency voltage is applied to the multiple propulsion motors under control. The output shaft of each propulsion motor is connected to a wheel via a coupling device, a gear device, etc. Because wheels are worn down due to friction with the rails, the wheel diameter, which is the radial length of the wheel, varies over time among the wheels. For this reason, it is difficult to make the wheel diameters of multiple wheels the same during railway vehicle operation, and wheel diameter differences inevitably occur among the multiple wheels. The wheel diameter differences cause wheel rotational speeds to differ among the wheels. Furthermore, railway vehicle gear devices reduce the rotational speed of the propulsion motors before transmitting it to the wheels, but unlike automotive gear devices, they have a fixed gear ratio. For this reason, wheel diameter differences among the wheels also cause differences in the rotational speed of the output shafts of the propulsion motors.

[0004] Against this technical background, Patent Document 1 below discloses an electric vehicle drive system that can individually control the rotational speed and torque of each wheel axle, even when multiple traction motors are connected in parallel to a common inverter. In this electric vehicle drive system, a planetary gear mechanism including an auxiliary motor is provided between each traction motor and each joint. The electric vehicle drive system uses the planetary gear mechanism to individually control the rotational speed of each auxiliary motor, thereby preventing the influence of wheel diameter differences from appearing on the rotational speed of the output shaft.

[0005] JP 2013-258819 A

[0006] However, the technology of Patent Document 1 requires the addition of an auxiliary motor and a planetary gear mechanism, which results in a problem of increased device size. Motor control devices that control propulsion motors are often mounted under the floor of railway vehicles, but the space under the floor is limited and often does not provide enough space for additional devices such as an auxiliary motor and a planetary gear mechanism.

[0007] The present disclosure has been made in view of the above, and has an object to provide a motor control device that collectively controls a plurality of propulsion motors while suppressing an increase in the size of the device.

[0008] To solve the above-mentioned problems and achieve the object, a motor control device according to the present disclosure is mounted on a railway vehicle and collectively controls multiple propulsion motors that provide driving force to the railway vehicle and other railway vehicles towed by the railway vehicle. The railway vehicle is equipped with a continuously variable transmission interposed between the propulsion motors and the wheel axles of the railway vehicle and configured to continuously change the gear ratio, which is the ratio of the motor speed (the rotational speed of the propulsion motors) to the wheel speed (the speed of the wheels connected to the wheel axles). The motor control device performs a first control that adjusts the gear ratio commanded to the continuously variable transmission based on wheel diameter information (information on the radial lengths of the multiple wheels).

[0009] The motor control device according to the present disclosure has the advantage of being able to collectively control a plurality of propulsion motors while preventing the device from becoming larger.

[0010] FIG. 1 is a diagram showing an example of the schematic configuration of a railway vehicle drive system including a motor control device according to embodiment 1; FIG. 2 is a diagram showing an example of the configuration of a bogie on which a propulsion motor that is the control target of the motor control device according to embodiment 1 is mounted; FIG. 3 is a diagram showing an image of the operation of a gear ratio command device provided in the railway vehicle drive system according to embodiment 1; FIG. 4 is a diagram used to explain the effect of the railway vehicle drive system according to embodiment 1;

[0011] A motor control device and a railway vehicle drive system according to an embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that in the accompanying drawings, the scale of each component may differ from the actual scale for ease of understanding. In the following description, multiple components of the same type will be indicated by subscripted symbols, but the subscripts will be omitted as appropriate when there is no need to distinguish between the individual components.

[0012] Embodiment 1. Figure 1 is a diagram showing an example of the general configuration of a railway vehicle drive system 100 including a motor control device 11 according to embodiment 1. The railway vehicle drive system 100 is a system that is mounted on a railway vehicle that runs on power supplied from an overhead line (not shown), and that applies driving force to the railway vehicle on which the drive unit is mounted and to other railway vehicles pulled by the railway vehicle.

[0013] The components of the railway vehicle traction system 100 can be divided into an information system and a drive system. The information system includes a train information management device 10 and a gear ratio command device 12. The drive system mainly includes a motor control device 11 and traction motors 3a and 3b. The traction motors 3a and 3b are three-phase motors that provide propulsive force to the railway vehicle. Although not shown, the motor control device 11 also includes a filter capacitor that smooths the overhead line voltage applied from the overhead line, an inverter that converts the DC voltage smoothed by the filter capacitor into an AC voltage with a variable voltage and variable frequency, and a control unit that controls the operation of the inverter.

[0014] The propulsion motors 3a and 3b are connected to the motor control device 11 via switch units 2a and 2b, respectively. The switch unit 2a switches between electrical open and closed states between the motor control device 11 and the propulsion motor 3a, and the switch unit 2b switches between electrical open and closed states between the motor control device 11 and the propulsion motor 3b.

[0015] The propulsion motor 3a is connected to the wheel 6a via a joint 4a and a gear device 5a, and the propulsion motor 3b is connected to the wheel 6b via a joint 4b and a gear device 5b. Figure 2 is a diagram showing an example of the configuration of a bogie 30 on which the propulsion motors 3a and 3b, which are the objects to be controlled by the motor control device 11 according to embodiment 1, are mounted. Figure 2 shows an example of how the propulsion motors 3a and 3b are mounted on a bogie frame 32.

[0016] The propulsion motors 3a, 3b are arranged diagonally on the bogie frame 32. A wheel axle 20a, on which the wheel 6a is fitted, and a wheel axle 20b, on which the wheel 6b is fitted, are rotatably mounted on the bogie frame 32. The wheel axle 20a is attached to a gear device 5a, and the wheel axle 20b is attached to a gear device 5b. The gear device 5a is connected to the propulsion motor 3a and the wheel axle 20a, and transmits driving force to the wheel axle 20a by reducing the rotational speed of the propulsion motor 3a. Similarly, the gear device 5b is connected to the propulsion motor 3b and the wheel axle 20b, and transmits driving force to the wheel axle 20b by reducing the rotational speed of the propulsion motor 3b. The rotary shaft 22a of the propulsion motor 3a and the pinion shaft 24a of the gear device 5a are flexibly connected by a joint 4a, and the rotary shaft 22b of the propulsion motor 3b and the pinion shaft 24b of the gear device 5b are flexibly connected by a joint 4b.

[0017] The gear devices 5a and 5b are equipped with continuously variable transmissions 26a and 26b, respectively. The continuously variable transmissions 26a and 26b are transmissions with functions similar to those of the CVTs (Continuously Variable Transmissions) used in modern automobiles and the like. The continuously variable transmission 26a is connected to the wheel axle 20a and the pinion shaft 24a. The continuously variable transmission 26a is interposed between the propulsion motor 3a and the wheel axle 20a and is configured to continuously change the gear ratio, which is the ratio of the motor speed to the wheel speed. The wheel speed is the speed of the wheel connected to the wheel axle 20a, and the motor speed is the rotational speed of the propulsion motor 3a, i.e., the rotational angular velocity (number of revolutions). The continuously variable transmission 26b is configured similarly to the continuously variable transmission 26a.

[0018] The propulsion motors 3 a, 3 b are provided with speed detectors 7 a, 7 b, respectively. The speed detectors 7 a, 7 b detect the motor speed, which is the rotational speed of the propulsion motors 3 a, 3 b. The motor speed values ​​detected by the speed detectors 7 a, 7 b are input to a motor control device 11 and a gear ratio command device 12.

[0019] In railway vehicle drive systems, sensorless control is a well-known technique that estimates the motor speed or the rotor position of the traction motor 3 without using a speed sensor or a position sensor, and controls the traction motor 3 based on the estimated motor speed or rotor position information. Therefore, in railway vehicle drive systems that use sensorless control, the speed detector 7 is not required.

[0020] Returning to the explanation of FIG. 1 , the motor control device 11 is connected to a train information management device 10 and a gear ratio command device 12. The train information management device 10 manages train information for a train composed of multiple railcars. The train information is information transmitted within the train and includes wheel diameter information, as defined herein. The wheel diameter information is information about the radial length of the wheels 6. The train information management device 10 manages the wheel diameter information for all railcars belonging to the train. The train information management device 10 also transmits the wheel diameter information to the motor control device 11 and the gear ratio command device 12 before the train begins operation. The motor control device 11 changes the gear ratio of each wheel 6a, 6b based on the wheel diameter information. The control for changing the gear ratio is performed by the motor control device 11 transmitting a command value for the gear ratio for each wheel 6a, 6b to the gear ratio command device 12, and the gear ratio command device 12 transmitting a control signal for controlling the gear ratio to the gear devices 5a, 5b.

[0021] The wheel diameter information transmitted to the motor control device 11 and the gear ratio command device 12 may be the wheel diameter information of all railcars belonging to the train, or may be only the wheel diameter information related to the wheels 6 of the bogie 30 on which the traction motor 3 under the control of the motor control device 11 and the gear ratio command device 12 is mounted. Furthermore, the wheel diameter information may be transmitted to only one of the motor control device 11 and the gear ratio command device 12. Note that, if the wheel diameter information is stored only in the motor control device 11, the gear ratio command value is calculated by the motor control device 11. In this configuration, the gear ratio command device 12 receives information related to the gear ratio command value output from the motor control device 11 and controls the continuously variable transmissions 26a, 26b based on the received command value. Note that, if the wheel diameter information is stored only in the gear ratio command device 12, the gear ratio command value is calculated by the gear ratio command device 12.

[0022] 1, the gear ratio command device 12 is configured as a component of the information system separate from the motor control device 11, but the gear ratio command device 12 may be configured as a component inside the motor control device 11. In this configuration, the effect is that the railway vehicle traction system 100 can be constructed without adding a new device.

[0023] On the other hand, the gear ratio command device 12 is a component of the information system and can be configured compactly, so it can be placed under a seat in a railway vehicle, for example. For this reason, even if the gear ratio command device 12 is configured as a component separate from the motor control device 11, it is believed that there will be almost no problem in securing installation space. If the gear ratio command device 12 is configured as a component separate from the motor control device 11, the degree of freedom in placement increases, making it possible to place it in a desired position in the railway vehicle. This has the effect of shortening the length of the connecting wiring connecting the gear ratio command device 12 and the gear device 5, compared to when the gear ratio command device 12 is configured inside the motor control device 11.

[0024] 1 illustrates a configuration in which one motor control device 11 collectively controls two propulsion motors 3a and 3b, but the configuration is not limited to this. The motor control device 11 may also be configured to collectively control three or more propulsion motors 3.

[0025] Figure 3 is a diagram showing an image of the operation of the gear ratio command device 12 provided in the railway vehicle drive system 100 according to the first embodiment. The horizontal axis of Figure 3 represents vehicle speed, and the vertical axis represents gear ratio. Vehicle speed is the traveling speed of the railway vehicle, and is synonymous with wheel speed. Ca is the gear ratio commanded to the continuously variable transmission 26a connected to wheel 6a, and gear ratio Cb is the gear ratio commanded to the continuously variable transmission 26b connected to wheel 6b. Furthermore, Ra is the wheel diameter of wheel 6a, and Rb is the wheel diameter of wheel 6b.

[0026] As described above, the gear devices 5a and 5b are equipped with the continuously variable transmissions 26a and 26b, respectively. Therefore, the gear ratios Ca and Cb for controlling the gear devices 5a and 5b change continuously as shown in the figure. Furthermore, as shown in FIG. 3, even when the vehicle speed changes, the gear ratios Ca and Cb are changed so that the ratio between the gear ratios Ca and Cb is the inverse ratio of the ratio between the wheel diameters Ra and Rb, i.e., Ca:Cb=Rb:Ra.

[0027] 3 shows an example in which the wheel diameter Rb is longer than the wheel diameter Ra. When the wheel diameter Rb is longer than the wheel diameter Ra, if the rotational speeds of the propulsion motors 3a and 3b are the same, the rotational speed of the wheels 6a and 6b will be higher than that of the wheels 6b. Therefore, when the wheel diameter Rb is longer than the wheel diameter Ra, the gear ratios Ca and Cb are set to the inverse ratio of the wheel diameters Ra and Rb. As a result, the rotational speeds of the propulsion motors 3a and 3b are controlled to be the same, and at the same time, the rotational speeds of the wheels 6a and 6b are controlled to be the same.

[0028] As described above, the motor control device 11 according to the first embodiment performs control to adjust the ratio of the speed ratios Ca and Cb commanded to the continuously variable transmissions 26a and 26b based on wheel diameter information, which is information about the radial lengths of the wheels 6a and 6b. In this document, this control may be referred to as "first control" as appropriate.

[0029] Fig. 4 is a diagram illustrating the effects of the railway vehicle drive system 100 according to Embodiment 1. In the explanation of Fig. 4, it is assumed that the traction motors 3a and 3b are induction motors.

[0030] The upper part of Figure 4 shows an example of operation when a single motor control device according to the prior art collectively controls the propulsion motors 3a and 3b. In the upper diagram, the horizontal axis represents the command speed, and the vertical axis represents the motor speed and gear ratio. In a conventional bogie configuration, the gear ratio is the ratio of the number of teeth of the large gear attached to the wheel axle 20 that meshes with the small gear attached to the pinion shaft 24 to the number of teeth of the small gear attached to the pinion shaft 24, and is the same for both gear units 5a and 5b. Therefore, if there is a difference in wheel diameter between the wheels 6a and 6b, the motor speeds of the propulsion motors 3a and 3b must be different. Furthermore, the difference in motor speeds increases as the command speed increases. Therefore, unless the wheel diameter difference between the wheels 6a and 6b is strictly controlled, collectively controlling the propulsion motors 3a and 3b is difficult.

[0031] The lower part of Figure 4 shows an example of operation when a single motor control device 11 according to embodiment 1 collectively controls the propulsion motors 3a and 3b. In the lower diagram, the horizontal axis represents the command speed, and the vertical axis represents the motor speed and the gear ratio. The conditions for the wheel diameters Ra and Rb are the same as in Figure 3, and the gear ratios Ca and Cb are set to the inverse ratio of the wheel diameters Ra and Rb. As shown in the figure, the motor speed is changed linearly as the command speed increases, but because the gear ratios Ca and Cb are appropriately set according to the wheel diameters Ra and Rb, if the motor speed is controlled to be the same between the propulsion motors 3a and 3b, the wheel speeds of the wheels 6a and 6b can also be made the same.

[0032] When the propulsion motors 3a, 3b are induction motors, it is possible to control the propulsion motors 3a, 3b collectively by utilizing the slip characteristic of induction motors. However, when using slip, while the frequency of the motor-applied voltage is the same for the propulsion motors 3a, 3b, the amount of slip differs between the propulsion motors 3a, 3b, resulting in an impedance difference. This impedance difference generates a current difference between the propulsion motors 3a, 3b. This current difference causes a torque difference between the propulsion motors 3a, 3b. If there is a torque difference and the torque is excessive, the wheel axle 20 to which excessive torque is applied may experience slippage or skidding. Furthermore, if an excessive current flows through a specific propulsion motor 3 due to the current difference, that specific propulsion motor 3 may abnormally overheat. To prevent these phenomena, it is necessary to always keep the wheel diameter difference within a certain range, which has been a constraint on railway operators.

[0033] When wheel diameter differences are strictly controlled, railway operators have had to select wheel diameters to be used while taking into consideration minimizing wheel diameter differences between wheel axles on the same bogie or vehicle. Furthermore, railway operators have had to stock more spare wheels than necessary, grind the wheels more than necessary, and implement measures to keep wheel diameter differences within specified limits, even if this shortens the wheel's lifespan. In contrast, by using the method of the first embodiment, there is no need to select wheel diameters to be used, and therefore there is no need to stock more spare wheels than necessary or grind the wheels more than necessary. This has the effect of significantly reducing the costs associated with spare wheels for railway vehicles and the costs required for railway vehicle wheel maintenance.

[0034] Next, a hardware configuration for realizing the control functions of motor control device 11 according to the first embodiment will be described with reference to Figures 5 and 6. Figure 5 is a block diagram showing an example of a hardware configuration for realizing the control functions of motor control device 11 according to the first embodiment. Figure 6 is a block diagram showing another example of a hardware configuration for realizing the control functions of motor control device 11 according to the first embodiment.

[0035] When realizing some or all of the control functions of the motor control device 11 according to embodiment 1, the configuration can include a processor 300 that performs calculations, a memory 302 that stores programs read by the processor 300, and an interface 304 that inputs and outputs signals, as shown in FIG. 5.

[0036] The processor 300 is a computing means. The processor 300 may be a computing means called a microprocessor, a microcomputer, a central processing unit (CPU), or a digital signal processor (DSP). Examples of the memory 302 include non-volatile or volatile semiconductor memory such as random access memory (RAM), read-only memory (ROM), flash memory, erasable programmable read-only memory (EPROM), and electrically programmable read-only memory (EEPROM), as well as magnetic disks, flexible disks, optical disks, compact disks, minidisks, and digital versatile disks (DVDs). The memory 302 may be a combination of multiple storage devices, such as a combination of RAM and EEPROM.

[0037] Memory 302 stores a program that executes the control functions of motor control device 11 according to embodiment 1. Processor 300 exchanges necessary information via interface 304, executes the program stored in memory 302, and refers to the table stored in memory 302, thereby performing the above-described processing. The results of calculations by processor 300 can be stored in memory 302.

[0038] 6 can be used to implement part of the control functions of the motor control device 11 according to the first embodiment. The processing circuit 303 can be a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. Information input to and output from the processing circuit 303 can be obtained via an interface 304.

[0039] Note that some of the processing in the control functions of the motor control device 11 according to the first embodiment may be performed by the processing circuit 303, and the processing that is not performed by the processing circuit 303 may be performed by the processor 300 and the memory 302.

[0040] As described above, the motor control device according to the first embodiment performs a first control that adjusts the gear ratio commanded to the continuously variable transmission based on wheel diameter information, which is information about the radial lengths of a plurality of wheels. The first control appropriately sets the gear ratio commanded to the continuously variable transmission provided in the gear device in accordance with the wheel diameter difference between the plurality of wheels, thereby enabling the motor speeds of the plurality of propulsion motors to be controlled to be the same, and the wheel speeds of the plurality of wheels to be the same. This makes it possible to realize a motor control device that collectively controls a plurality of propulsion motors while minimizing the device size.

[0041] Furthermore, the railway vehicle drive system according to the first embodiment can be realized by mounting the motor control device described above on a railway vehicle and mounting a gear device equipped with the continuously variable transmission described above on a bogie on which a propulsion motor is mounted. When the railway vehicle drive system according to the first embodiment is used, railway operators do not need to select the wheel diameter to be used, and therefore do not need to stock more spare wheels than necessary, and do not need to perform more wheel grinding work than necessary. This allows railway operators to enjoy the effect of significantly reducing the costs associated with spare wheels for railway vehicles and the costs required for railway vehicle wheel maintenance work.

[0042] The wheel diameter information required for implementing the first control may be stored in the motor control device or in a train information management device that manages train information for a train consisting of multiple railway cars. The railway vehicle may also be equipped with a gear ratio command device that receives information related to the gear ratio command value output from the motor control device. When the gear ratio command device is installed, the gear ratio command value output from the motor control device is transmitted to the continuously variable transmission via the gear ratio command device. When the gear ratio command device is an internal component of the motor control device, a railway vehicle drive system can be constructed without adding a new device. When the gear ratio command device is an external component of the motor control device, the degree of freedom in placement is increased, allowing the gear ratio command device to be placed at a desired location on the railway vehicle. This allows for a shorter length of the wiring connecting the gear ratio command device and the gear device compared to when the gear ratio command device is an internal component of the motor control device.

[0043] Embodiment 2. Figure 7 is a diagram illustrating the operation of the main parts of a motor control device 11 according to embodiment 2. The upper part of Figure 7 shows a waveform indicating the rotor position of the propulsion motor 3a, and the lower part of Figure 7 shows a waveform indicating the rotor position of the propulsion motor 3b. The horizontal axis of Figure 7 represents time. The lower part of Figure 7 also shows, in part A indicated by a dashed oval, how the rotor position of the propulsion motor 3b behaves differently from normal. In part A, the solid line indicates the behavior before control, and the dashed line indicates the behavior after control.

[0044] In rainy weather, when traveling around a curve, or in other situations, the adhesion coefficient of the wheels 6 may decrease, causing the railway vehicle to spin or slide. If the railway vehicle spins or slides, control is performed to prevent this. In the individual system, the rotation of each wheel set 20 can be individually and precisely controlled. For example, if a wheel 6 spins or slides, the output of the corresponding traction motor 3 can be transiently fine-tuned from a set value in accordance with the state of each wheel 6 to prevent the wheel from spinning or sliding. On the other hand, in the collective system, if there is a large difference in wheel diameter between multiple wheels 6, conventional motor control devices cannot individually control the output of the traction motor 3, making it difficult to precisely control the wheel spin or slide.

[0045] In order to address the above problem, the motor control device 11 according to the second embodiment performs control in accordance with the flow shown in Fig. 8. Fig. 8 is a flowchart showing the flow of control performed by the motor control device 11 according to the second embodiment.

[0046] The motor control device 11 acquires the detection values ​​of the speed detectors 7a and 7b (step S11). Next, the motor control device 11 calculates the rotor positions of the propulsion motors 3a and 3b based on the detection values ​​of the speed detectors 7a and 7b (step S12) and calculates the phase difference between the rotor positions of the propulsion motors 3a and 3b (step S13). The motor control device 11 compares the rotor position phase difference calculated in step S13 with a determination threshold (step S14).

[0047] If the phase difference is greater than the determination threshold (step S14, Yes), the motor control device 11 performs a second control to adjust the gear ratio of the continuously variable transmission 26 connected to the propulsion motor 3 whose rotor position is fluctuating (step S15). "Adjusting the gear ratio" here means adjusting the gear ratio of the continuously variable transmission 26 in a direction that reduces the phase difference in rotor position. After completing the processing of step S15, the process returns to step S11, and the processing from step S11 is repeated.

[0048] If the phase difference is equal to or smaller than the determination threshold (step S14, No), the process returns to the first control described in the first embodiment (step S16). After the process of step S16 is completed, the process returns to step S11, and the process from step S11 is repeated.

[0049] In the determination process of step S14, the case where the phase difference is equal to the determination threshold is determined as "No", but the case where the phase difference is equal to the determination threshold may be determined as "Yes". In other words, the case where the phase difference is equal to the determination threshold may be determined as either "Yes" or "No".

[0050] By the control of the flow shown in FIG. 8, the rotor position of the propulsion motor 3b is controlled in a direction that eliminates the deviation of the rotor position, as shown by the broken line in part A of FIG.

[0051] Fig. 9 is the first diagram for explaining the behavior under the control of the flow shown in Fig. 8. In Fig. 9, both the upper and lower stages show waveforms of rotor position change over time, similar to Fig. 8.

[0052] Figure 9 shows an example where wheel 6b connected to propulsion motor 3b spins, as indicated by the dashed oval in the lower part. The solid line shows the behavior before control, and the dashed line shows the behavior after control. When wheel 6b spins, a phase difference exceeding the determination threshold occurs between the rotor position of propulsion motor 3b, which drives wheel 6b, and the rotor position of propulsion motor 3a, which drives wheel 6a. Therefore, by implementing the control shown in Figure 8, the gear ratio of continuously variable transmission 26b on the propulsion motor 3b side is adjusted, and control is performed in a direction that eliminates the deviation in rotor position, as indicated by the dashed line. This eliminates the deviation in rotor position due to the wheel 6b spinning.

[0053] Fig. 10 is a second diagram for explaining the behavior caused by the control of the flow shown in Fig. 8. Fig. 11 is a third diagram for explaining the behavior caused by the control of the flow shown in Fig. 8.

[0054] Figure 10 shows an example of a case where wheel 6b connected to propulsion motor 3b slides at the location indicated by the dashed oval on the lower side. The solid line shows the behavior before control, and the dashed line shows the behavior after control. When wheel 6b slides, a phase difference exceeding the judgment threshold occurs between the rotor position of propulsion motor 3b driving wheel 6b and the rotor position of propulsion motor 3a driving wheel 6a. Therefore, by implementing the control shown in Figure 8, the gear ratio of continuously variable transmission 26b on the propulsion motor 3b side is adjusted, and control is performed in a direction that eliminates the deviation in rotor position, as indicated by the dashed line. This eliminates the deviation in rotor position caused by wheel 6b sliding.

[0055] 10 shows an example in which, when a phase difference that indicates a slide is detected, the phase difference is eliminated by increasing the phase advance of the rotor position on the propulsion motor 3b side, but this is not limiting. As shown in FIG. 11, the phase difference may be eliminated by decreasing the phase advance of the rotor position on the propulsion motor 3b side.

[0056] As described above, the motor control device according to the second embodiment calculates the rotor position phase difference of the propulsion motor based on the detection value of the speed detector provided in the propulsion motor, and performs second control to adjust the gear ratio based on the rotor position phase difference. The motor control device performs this second control when the rotor position phase difference is greater than the determination threshold, and adjusts the gear ratio of the continuously variable transmission connected to the propulsion motor whose rotor position is fluctuating. Furthermore, when the rotor position phase difference falls below the determination threshold, the control returns to the first control. These first and second controls provide the effect of the first embodiment, as well as the effect of quickly eliminating skidding or wheel slippage that is likely to occur due to wheel diameter differences.

[0057] Furthermore, the railway vehicle drive system according to the second embodiment can be realized by mounting the gear device equipped with the continuously variable transmission described in the first embodiment on the bogie on which the propulsion motor is mounted, and mounting the motor control device described in the second embodiment on the railway vehicle. When the railway vehicle drive system according to the second embodiment is used, railway operators can enjoy not only the effect of the first embodiment, but also the effect of the second embodiment, that is, the ability to quickly eliminate skidding or wheel slip.

[0058] The technique according to the second embodiment is particularly effective when the propulsion motors 3 a, 3 b are synchronous motors, but is not intended to prevent application to induction motors. Even if the propulsion motors 3 a, 3 b are induction motors, the effects of the second embodiment described above can be enjoyed.

[0059] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0060] 2a, 2b Opening and closing section, 3, 3a, 3b Propulsion motor, 4a, 4b Coupling, 5, 5a, 5b Gear device, 6, 6a, 6b Wheel, 7, 7a, 7b Speed ​​detector, 10 Train information management device, 11 Motor control device, 12 Gear ratio command device, 20, 20a, 20b Wheel shaft, 22a, 22b Rotating shaft, 24, 24a, 24b Pinion shaft, 26, 26a, 26b Continuously variable transmission, 30 Bogie, 32 Bogie frame, 100 Railway vehicle drive system, 300 Processor, 302 Memory, 303 Processing circuit, 304 Interface.

Claims

1. A motor control device that is mounted on a railway vehicle and collectively controls a plurality of traction motors that provide driving force to the railway vehicle and another railway vehicle towed by the railway vehicle, the railway vehicle includes a continuously variable transmission that is interposed between the traction motor and a wheel axle of the railway vehicle and is configured to be able to continuously change a gear ratio that is a ratio of a motor speed, which is the rotational speed of the traction motor, to a wheel speed, which is the speed of a wheel coupled to the wheel axle; The motor control device performs a first control to adjust the gear ratio to be instructed to the continuously variable transmission based on wheel diameter information that is information on the radial lengths of the wheels. A motor control device comprising:

2. When the first control is performed, the ratio of the speed change ratio is adjusted so that the rotation speeds of the plurality of traction motors are the same.

2. The motor control device according to claim 1 .

3. The wheel diameter information is stored in the motor control device.

2. The motor control device according to claim 1 .

4. The railcar is equipped with a train information management device that manages train information of a train made up of a plurality of railcars, and the wheel diameter information is transmitted from the train information management device to the motor control device and stored in the motor control device.

2. The motor control device according to claim 1 .

5. the propulsion motor is provided with a speed detector that detects a rotational speed of the propulsion motor; Calculating a phase difference of a rotor position of the propulsion motor based on the detection value of the speed detector; A second control is performed to adjust the speed ratio based on the phase difference of the rotor position.

5. The motor control device according to claim 1, wherein the motor control device comprises:

6. Implementing the second control when the phase difference of the rotor position is greater than a determination threshold value; In the second control, the gear ratio of the continuously variable transmission connected to the traction motor whose rotor position is fluctuating is adjusted.

6. The motor control device according to claim 5 .

7. When the phase difference of the rotor position falls below a judgment threshold, the first control is restored.

7. The motor control device according to claim 6.

8. a plurality of traction motors mounted on the railcar to provide driving force to the railcar and other railcars towed by the railcar; a motor control device that collectively controls the plurality of propulsion motors; a continuously variable transmission that is interposed between the traction motor and a wheel axle of the railway vehicle and is configured to be able to change a gear ratio that is a ratio of a motor speed, which is the rotational speed of the traction motor, to a wheel speed, which is the speed of a wheel connected to the wheel axle; Equipped with The motor control device performs a first control to adjust the gear ratio to be instructed to the continuously variable transmission based on wheel diameter information that is information on the radial length of the wheel. A railway vehicle drive system comprising:

9. When the first control is performed, the motor control device adjusts the ratio of the gear ratio so that the rotation speeds of the plurality of traction motors are the same.

9. A rail vehicle drive system according to claim 8.

10. The wheel diameter information is stored in the motor control device.

9. A rail vehicle drive system according to claim 8.

11. The railcar is equipped with a train information management device that manages train information of a train made up of a plurality of railcars, and the wheel diameter information is transmitted from the train information management device to the motor control device and stored in the motor control device.

9. A rail vehicle drive system according to claim 8.

12. the railway vehicle is equipped with a gear ratio command device that receives information regarding the gear ratio command value output from the motor control device, The gear ratio command device commands the received gear ratio command value to the continuously variable transmission device.

9. A rail vehicle drive system according to claim 8.

13. the propulsion motor is provided with a speed detector that detects a rotational speed of the propulsion motor; The motor control device calculates a phase difference of a rotor position of the propulsion motor based on the detection value of the speed detector, and performs a second control to adjust the gear ratio based on the phase difference of the rotor position.

13. A railway vehicle drive system according to any one of claims 8 to 12.

14. The motor control device performs the second control when the phase difference of the rotor position is greater than a determination threshold value, and in the second control, adjusts the gear ratio of the continuously variable transmission connected to the traction motor whose rotor position fluctuates.

14. A rail vehicle drive system according to claim 13.

15. The motor control device returns to the first control when the phase difference of the rotor position falls below a determination threshold value.

15. A rail vehicle drive system according to claim 14.