Motor control device and railway vehicle drive 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

Technical Field

[0001] The present disclosure relates to a motor control device for collectively controlling a plurality of propulsion motors mounted on a railway vehicle, and a railway vehicle drive system including the motor control device.

Background Art

[0002] Conventionally, in a railway vehicle drive system, a motor control device for controlling a propulsion motor has been used to collectively control a plurality of propulsion motors in units such as two or four. The collective control method for collectively controlling a plurality of propulsion motors can significantly reduce the weight and volume of the control device compared to the individual control method in which one control device individually controls one propulsion motor, enabling a significant reduction in vehicle weight.

[0003] When a plurality of propulsion motors are controlled in a collective manner, the same frequency voltage is applied to the plurality of propulsion motors under control. The output shafts of the respective propulsion motors are connected to the wheels via a coupling device, a gear device, etc. Since the wheels are worn by friction with the rail, etc., the wheel diameter, which is the length in the radial direction of the wheel, will differ between the wheels over time. Therefore, it is difficult to make the wheel diameters the same among the plurality of wheels during the operation of the railway vehicle, and a wheel diameter difference will inevitably occur among the plurality of wheels. The wheel diameter difference causes the rotational speeds of the wheels to differ between the wheels. Also, although the gear device for railway vehicles reduces the rotational speed of the propulsion motor and transmits it to the wheels, unlike the gear device for automobiles, the gear ratio is fixed. For this reason, the wheel diameter difference among the wheels also causes a difference in the rotational speed of the output shafts of the respective propulsion motors.

[0004] Under the above technical background, Patent Document 1 below discloses an electric vehicle drive system that can individually control the rotational speed and torque for each wheel axle of the wheels even when a plurality of propulsion 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 one by one between each propulsion motor and each joint. The electric vehicle drive system uses the planetary gear mechanism to individually control the rotational speed of each auxiliary motor so that the influence of the wheel diameter difference does not appear in the rotational speed of the output shaft.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the technology of Patent Document 1 has a problem that it is necessary to add an auxiliary motor and a planetary gear mechanism, which causes the device to become larger. The motor control device for controlling the propulsion motor is often mounted under the floor of a railway vehicle, but the space under the floor is limited, and there is often not enough space to additionally install devices such as an auxiliary motor and a planetary gear mechanism.

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

Means for Solving the Problems

[0008] In order to solve the above-described problems and achieve the object, the motor control device according to the present disclosure is mounted on a railway vehicle and collectively controls a plurality of propulsion motors that apply driving force to the railway vehicle and other railway vehicles towed by the railway vehicle. The railway vehicle includes a continuously variable transmission device that is interposed between the propulsion motor and the wheel axle of the railway vehicle and is configured to be able to continuously change the transmission ratio, which is the ratio of the motor speed, which is the rotational speed of the propulsion motor, to the wheel speed, which is the speed of the wheels connected to the wheel axle. The motor control device performs first control to adjust the transmission ratio commanded to the continuously variable transmission device based on the wheel diameter information, which is information on the length in the radial direction of a plurality of wheels.

Effect of the Invention

[0009] According to the motor control device according to the present disclosure, it is possible to collectively control a plurality of propulsion motors while suppressing an increase in the size of the device.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0011] With reference to the accompanying drawings below, a motor control device and a railway vehicle drive system according to embodiments of the present disclosure will be described in detail. In the accompanying drawings, for ease of understanding, the scales of the respective members may be different from the actual ones. Further, in the following description, a plurality of components of the same type are denoted by reference numerals with suffixes, but when not distinguishing each of the components, the suffix notation is appropriately omitted.

[0012] Embodiment 1. FIG. 1 is a diagram showing a schematic configuration example of a railway vehicle drive system 100 including a motor control device 11 according to Embodiment 1. The railway vehicle drive system 100 is mounted on a railway vehicle that runs by electric power supplied from an overhead line (not shown), and is a system that imparts driving force to a railway vehicle equipped with a driving device and other railway vehicles towed by the railway vehicle.

[0013] The components of the railway vehicle drive system 100 can be classified 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. Further, the drive system mainly includes a motor control device 11 and propulsion motors 3a and 3b. The propulsion motors 3a and 3b are three-phase motors that impart propulsion force to the railway vehicle. Although not shown in the figure, the motor control device 11 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 a variable frequency, and a control unit that controls the operation of the inverter.

[0014] The propulsion motors 3a and 3b are respectively connected to the motor control device 11 via the opening / closing parts 2a and 2b. The opening / closing part 2a switches between electrical disconnection and conduction between the motor control device 11 and the propulsion motor 3a, and the opening / closing part 2b switches between electrical disconnection and conduction between the motor control device 11 and the propulsion motor 3b.

[0015] The propulsion motor 3a is connected to the wheel 6a via the joint 4a and the gear device 5a, and the propulsion motor 3b is connected to the wheel 6b via the joint 4b and the gear device 5b. FIG. 2 is a diagram showing a configuration example of the carriage 30 on which the propulsion motors 3a and 3b, which are control targets of the motor control device 11 according to the first embodiment, are mounted. FIG. 2 shows an example of mounting the propulsion motors 3a and 3b on the carriage frame 32.

[0016] The propulsion motors 3a and 3b are arranged diagonally in the carriage frame 32. In the carriage frame 32, a wheel shaft 20a with the wheel 6a fitted thereon and a wheel shaft 20b with the wheel 6b fitted thereon are rotatably installed. The wheel shaft 20a is attached to the gear device 5a, and the wheel shaft 20b is attached to the gear device 5b. The gear device 5a is connected to the propulsion motor 3a and the wheel shaft 20a, and reduces the rotational speed of the propulsion motor 3a and transmits the driving force to the wheel shaft 20a. Similarly, the gear device 5b is connected to the propulsion motor 3b and the wheel shaft 20b, and reduces the rotational speed of the propulsion motor 3b and transmits the driving force to the wheel shaft 20b. The rotary shaft 22a of the propulsion motor 3a and the pinion shaft 24a of the gear device 5a are flexibly connected by the 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 the joint 4b.

[0017] The gear devices 5a and 5b are each provided with a stepless speed change device 26a and 26b. The stepless speed change devices 26a and 26b are speed change devices having the same function as a CVT (Continuously Variable Transmission) used in recent automobiles and the like. The stepless speed change device 26a is connected to the wheel shaft 20a and the pinion shaft 24a. The stepless speed change device 26a is interposed between the propulsion motor 3a and the wheel shaft 20a and is configured to be able to continuously change the speed 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 shaft 20a, and the motor speed is the rotational speed of the propulsion motor 3a, that is, the rotational angular velocity (rotational speed). The stepless speed change device 26b is also configured in the same manner as the stepless speed change device 26a.

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

[0019] Note that in a railway vehicle drive system, sensorless control, which is a technology for estimating the motor speed or the rotor position of the propulsion motor 3 without using a speed sensor or a position sensor and controlling the propulsion motor 3 based on the information of the estimated motor speed or rotor position, is known. Therefore, in a railway vehicle drive system to which sensorless control is applied, the speed detector 7 is unnecessary.

[0020] Returning to the description of FIG. 1, the motor control device 11 is connected to the train information management device 10 and the gear ratio command device 12. The train information management device 10 is a device that manages train information of a train formed by a plurality of railway vehicles. The train information is information transmitted within the train and includes the wheel diameter information in this article. The wheel diameter information is information on the length in the radial direction of the wheels 6. The train information management device 10 manages the wheel diameter information of all the railway vehicles belonging to the train. Also, the train information management device 10 transmits the wheel diameter information to the motor control device 11 and the gear ratio command device 12 before the train runs. Based on the wheel diameter information, the motor control device 11 changes the gear ratio of the wheels 6a and 6b for each of the wheels 6a and 6b. The control for changing the gear ratio is implemented by the motor control device 11 transmitting a command value of the gear ratio for each of the wheels 6a and 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 and 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 the railway vehicles belonging to the train, or may be only the wheel diameter information regarding the wheels 6 of the bogie 30 on which the propulsion motor 3 under the control of the motor control device 11 and the gear ratio command device 12 is mounted. Also, the wheel diameter information may be transmitted to only one of the motor control device 11 and the gear ratio command device 12. When the wheel diameter information is held only by the motor control device 11, the command value of the gear ratio is calculated by the motor control device 11. In the case of this configuration, the gear ratio command device 12 receives information regarding the command value of the gear ratio output from the motor control device 11 and controls the continuously variable transmission devices 26a and 26b based on the received command value. When the wheel diameter information is held only by the gear ratio command device 12, the command value of the gear ratio is calculated by the gear ratio command device 12.

[0022] In FIG. 1, the gear ratio command device 12 is configured separately from the motor control device 11 as a component of the information system. However, the gear ratio command device 12 may be configured as a component inside the motor control device 11. In this case, the effect that the railway vehicle drive system 100 can be constructed without adding a new device is obtained.

[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 also be arranged under the seat of the railway vehicle or the like. 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 considered that almost no problem of securing the mounting space occurs. When the gear ratio command device 12 is configured as a component separate from the motor control device 11, the degree of freedom in arrangement increases, so it can be arranged at a desired position in the railway vehicle. Thereby, the effect that the length of the connection wiring connecting the gear ratio command device 12 and the gear device 5 can be shortened compared with the case where the gear ratio command device 12 is configured inside the motor control device 11 is obtained.

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

[0025] FIG. 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 Embodiment 1. The vehicle speed is shown on the horizontal axis of FIG. 3, and the gear ratio is shown on the vertical axis. The vehicle speed is the running speed of the railway vehicle and is synonymous with the wheel speed. Ca is the gear ratio commanded to the continuously variable transmission 26a connected to the wheel 6a, and the gear ratio Cb is the gear ratio commanded to the continuously variable transmission 26b connected to the wheel 6b. Also, Ra is the wheel diameter of the wheel 6a, and Rb is the wheel diameter of the wheel 6b.

[0026] As described above, the gear units 5a and 5b each include a stepless transmission 26a and 26b. Therefore, the gear ratios Ca and Cb for controlling the gear units 5a and 5b vary continuously as shown in the figure. Also, as shown in FIG. 3, even when the vehicle speed changes, the gear ratios Ca and Cb are changed such that the ratio of the gear ratios Ca and Cb is the inverse ratio of the ratios of the wheel diameters Ra and Rb, that is, Ca:Cb = Rb:Ra.

[0027] FIG. 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 and the rotational speeds of the propulsion motors 3a and 3b are the same, the rotational speed of the wheel 6b is greater than that of the wheel 6a. For this reason, 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. Thereby, 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 gear ratios Ca and Cb commanded to the stepless transmissions 26a and 26b based on the wheel diameter information, which is information on the lengths in the radial direction of the wheels 6a and 6b. In this document, this control may be appropriately described as "first control".

[0029] FIG. 4 is a diagram for explaining the effects of the railway vehicle drive system 100 according to the first embodiment. In the description of FIG. 4, it is assumed that the propulsion motors 3a and 3b are induction motors.

[0030] On the upper side of FIG. 4, an operation example is shown when one motor control device according to the prior art controls the propulsion motors 3a and 3b together. In the upper figure, the horizontal axis represents the command speed, and the vertical axis represents the motor speed and the gear ratio. The gear ratio is the ratio of the number of teeth of the large gear provided on the wheel shaft 20 and meshing with the small gear to the number of teeth of the small gear provided on the pinion shaft 24 in the configuration of the conventional carriage, and is the same for the gear devices 5a and 5b. Therefore, when there is a wheel diameter difference between the wheels 6a and 6b, it is necessary to make the motor speeds different between the propulsion motors 3a and 3b. Also, as the command speed increases, the difference in motor speed increases. For this reason, if the wheel diameter difference between the wheels 6a and 6b is not strictly controlled, it is difficult to control the propulsion motors 3a and 3b together.

[0031] On the lower side of FIG. 4, an operation example is shown when one motor control device 11 according to Embodiment 1 controls the propulsion motors 3a and 3b together. In the lower figure, the horizontal axis represents the command speed, and the vertical axis represents the motor speed and the transmission ratio. The conditions of the wheel diameters Ra and Rb are the same as in FIG. 3, and it is assumed that the transmission 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 changes linearly as the command speed increases. However, since the transmission 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 can also be made the same between the wheels 6a and 6b.

[0032] When the propulsion motors 3a and 3b are induction motors, it is possible to control the propulsion motors 3a and 3b collectively by utilizing the slip peculiar to induction motors. However, when utilizing slip, while the frequency of the motor applied voltage is the same for the propulsion motors 3a and 3b, the slip amount differs between the propulsion motors 3a and 3b, resulting in an impedance difference. Due to this impedance difference, a current difference occurs between the propulsion motors 3a and 3b. This current difference causes a torque difference between the propulsion motors 3a and 3b. When there is a torque difference and the torque is excessive, there is a risk of wheel spin or skid occurring on the wheel axle 20 to which the excessive torque is applied. Also, if an excessive current flows through a specific propulsion motor 3 due to the current difference, there is a risk of the specific propulsion motor 3 overheating abnormally. To prevent these phenomena, it was necessary to always keep the wheel diameter difference within a certain limit, which was a constraint on railway operators.

[0033] When strictly managing the wheel diameter difference, railway operators needed to select the wheel diameters to be used while considering that the wheel diameter difference between the wheel axles within the same car body or the same vehicle should be minimized as much as possible. Also, railway operators needed to hold more wheel spare parts than necessary, perform operations to shave the wheels more than necessary, and even shorten the wheel life to keep the wheel diameter difference within the specified value. In contrast, if the method of Embodiment 1 is used, there is no need to select the wheel diameters to be used, so there is no need to hold more wheel spare parts than necessary, and there is no need to perform operations to shave the wheels more than necessary. As a result, the effect of significantly reducing the cost related to the wheel spare parts of railway vehicles and the cost required for the maintenance work of the wheels of railway vehicles can be obtained.

[0034] Next, the hardware configuration for realizing the control function of the motor control device 11 according to the above-described Embodiment 1 will be described with reference to the drawings of FIGS. 5 and 6. FIG. 5 is a block diagram showing an example of the hardware configuration for realizing the control function of the motor control device 11 according to Embodiment 1. FIG. 6 is a block diagram showing another example of the hardware configuration for realizing the control function of the motor control device 11 according to Embodiment 1.

[0035] When realizing part or all of the control functions of the motor control device 11 according to Embodiment 1, as shown in FIG. 5, it can be configured to include a processor 300 that performs calculations, a memory 302 in which a program read by the processor 300 is stored, and an interface 304 that inputs and outputs signals.

[0036] The processor 300 is a calculation means. The processor 300 may be a calculation means called a microprocessor, a microcomputer, a CPU (Central Processing Unit), or a DSP (Digital Signal Processor). Also, examples of the memory 302 include non-volatile or volatile semiconductor memories such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable ROM), and EEPROM (registered trademark) (Electrically EPROM), magnetic disks, flexible disks, optical disks, compact disks, mini disks, and DVDs (Digital Versatile Disc). Note that the memory 302 may combine a plurality of storage devices, such as a combination of RAM and EEPROM.

[0037] A program for executing the control functions of the motor control device 11 according to Embodiment 1 is stored in the memory 302. The processor 300 exchanges necessary information via the interface 304, the processor 300 executes the program stored in the memory 302, and the processor 300 refers to the table stored in the memory 302, whereby the above-described processing can be performed. The calculation result by the processor 300 can be stored in the memory 302.

[0038] In addition, when implementing a part of the control function of the motor control device 11 according to Embodiment 1, the processing circuit 303 shown in FIG. 6 can also be used. The processing circuit 303 corresponds to 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 the processing circuit 303 and information output from the processing circuit 303 can be obtained via the interface 304.

[0039] Note that a part of the processing in the control function of the motor control device 11 according to Embodiment 1 may be performed by the processing circuit 303, and the processing 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 Embodiment 1 performs first control to adjust the gear ratio commanded to the continuously variable transmission based on the wheel diameter information, which is information on the lengths in the radial directions of a plurality of wheels. By the first control, since the gear ratio commanded to the continuously variable transmission provided in the gear device is appropriately set according to the wheel diameter difference between the plurality of wheels, the motor speed can be controlled to be the same among the plurality of propulsion motors, and the wheel speeds can also be made the same among the plurality of wheels. Thereby, it is possible to realize a motor control device that collectively controls a plurality of propulsion motors while suppressing an increase in the size of the device.

[0041] In addition, the railway vehicle drive system according to Embodiment 1 can be realized by mounting the above motor control device on a railway vehicle and mounting the gear device provided with the above continuously variable transmission on the bogie on which the propulsion motor is mounted. When the railway vehicle drive system according to Embodiment 1 is used, a railway operator does not need to select the wheel diameter to be used, so there is no need to hold spare parts for wheels more than necessary, and there is no need to perform work to shave wheels more than necessary. Thereby, the railway operator can enjoy the effect of significantly reducing the cost related to the spare parts of the wheels of the railway vehicle and the cost required for the maintenance work of the wheels of the railway vehicle.

[0042] Note that the wheel diameter information required for implementing the above first control may be held in the motor control device, or may be held in a train information management device that manages the train information of a train formed by a plurality of railway vehicles. Further, the railway vehicle may be equipped with a transmission ratio command device that receives information regarding the command value of the transmission ratio output from the motor control device. When the transmission ratio command device is mounted, the command value of the transmission ratio output from the motor control device is commanded to the continuously variable transmission device via the transmission ratio command device. When the transmission ratio command device is a component inside the motor control device, it is possible to enjoy the effect that a railway vehicle drive system can be constructed without newly installing a device. Also, when the transmission ratio command device is a component outside the motor control device, the degree of freedom in arrangement increases, and it can be arranged at a desired position in the railway vehicle. Thereby, compared with the case where the transmission ratio command device is a component inside the motor control device, it is possible to enjoy the effect that the length of the connection wiring connecting the transmission ratio command device and the gear device can be shortened.

[0043] Embodiment 2. FIG. 7 is a diagram for explaining the operation of the main part in the motor control device 11 according to Embodiment 2. A waveform indicating the rotor position of the propulsion motor 3a is shown on the upper side of FIG. 7, and a waveform indicating the rotor position of the propulsion motor 3b is shown on the lower side of FIG. 7. The horizontal axis of FIG. 7 represents time. Further, on the lower side of FIG. 7, in the portion A indicated by the broken-line ellipse, a state where the rotor position of the propulsion motor 3b shows a behavior different from normal is shown. In portion A, the solid line indicates the behavior before control, and the broken line indicates the behavior after control.

[0044] In the case of a railway vehicle, when running on a curve or in rainy weather, the adhesion coefficient of the wheels 6 may decrease, resulting in wheel spin or skidding. When the railway vehicle experiences wheel spin or skidding, control is performed to suppress these conditions. In the case of the individual method, it is possible to finely control the rotation of each wheel axle 20 individually. For example, when wheel spin or skidding occurs in the wheel 6, it is possible to suppress wheel spin or skidding by transiently fine-tuning the output of the corresponding propulsion motor 3 from the set value according to the state of each wheel 6. On the other hand, in the case of the batch method, when the wheel diameter difference between a plurality of wheels 6 is large, it is difficult to perform fine control for wheel spin or skidding with a conventional motor control device because the output of the propulsion motor 3 cannot be controlled individually.

[0045] To address the above problems, the motor control device 11 according to Embodiment 2 performs control according to the flow shown in FIG. 8. FIG. 8 is a flowchart showing the control flow by the motor control device 11 according to Embodiment 2.

[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 phase difference between the rotor positions calculated in step S13 with a determination threshold value (step S14).

[0047] When the phase difference is greater than the determination threshold value (step S14, Yes), the motor control device 11 performs 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). The "adjustment of the gear ratio" mentioned here means adjusting the gear ratio of the continuously variable transmission 26 in the direction in which the phase difference between the rotor positions becomes smaller. After the process of step S15 is completed, the process returns to step S11, and the process from step S11 is repeated.

[0048] When the phase difference is equal to or less than the determination threshold value (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 described above, when the phase difference is equal to the determination threshold value, it is determined as "No", but it may be determined as "Yes". That is, when the phase difference is equal to the determination threshold value, it 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 the direction in which the deviation of the rotor position is eliminated, as shown by the broken line in part A of FIG. 7.

[0051] FIG. 9 is a first diagram for explaining the behavior by the control of the flow shown in FIG. 8. In FIG. 9, the time change waveforms of the rotor positions are shown on both the upper and lower sides, similar to FIG. 8.

[0052] In FIG. 9, an example is shown where wheel spin occurs at the location indicated by the broken-line ellipse on the lower side. The solid line represents the behavior before control, and the broken line represents the behavior after control. When wheel spin occurs in wheel 6b, a phase difference exceeding the determination threshold value occurs between the rotor position of propulsion motor 3b that drives wheel 6b and the rotor position of propulsion motor 3a that drives wheel 6a. Therefore, by implementing the control shown in FIG. 8, the gear ratio of the stepless transmission 26b on the propulsion motor 3b side is adjusted and controlled in the direction in which the deviation of the rotor position is eliminated, as shown by the broken line. As a result, the deviation of the rotor position due to the wheel spin of wheel 6b is eliminated.

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

[0054] In FIG. 10, an example is shown in which a slip occurs in the wheel 6b connected to the propulsion motor 3b at the location indicated by the dashed ellipse on the lower side. The solid line represents the behavior before control, and the dashed line represents the behavior after control. When the wheel 6b slips, a phase difference exceeding the determination threshold occurs between the rotor position of the propulsion motor 3b that drives the wheel 6b and the rotor position of the propulsion motor 3a that drives the wheel 6a. Therefore, by implementing the control shown in FIG. 8, the gear ratio of the continuously variable transmission 26b on the propulsion motor 3b side is adjusted, and control is performed in a direction to eliminate the shift in the rotor position as shown by the dashed line. As a result, the shift in the rotor position due to the slip of the wheel 6b is eliminated.

[0055] FIG. 10 shows an example in which the phase difference is eliminated by increasing the advancement of the phase of the rotor position on the propulsion motor 3b side when a phase difference determined to be a slip is detected, but the present invention is not limited to this example. As shown in FIG. 11, the phase difference may be eliminated by decreasing the advancement of the phase 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 phase difference of the rotor position of the propulsion motor based on the detection value of the speed detector provided in the propulsion motor, and performs a second control for adjusting the gear ratio based on the phase difference of the rotor position. This second control is performed when the phase difference of the rotor position is greater than the determination threshold, and the gear ratio of the continuously variable transmission connected to the propulsion motor whose rotor position is fluctuating is adjusted. Further, when the phase difference of the rotor position decreases below the determination threshold, the control returns to the first control. By these first and second controls, in addition to the effects of the first embodiment, an effect can be obtained in which slip or idling that is likely to occur due to the wheel diameter difference can be quickly eliminated.

[0057] In addition, the railway vehicle drive system according to Embodiment 2 can be realized by mounting the gear unit equipped with the stepless speed changer described in Embodiment 1 on the bogie on which the propulsion motor is mounted, and mounting the motor control device described in Embodiment 2 on the railway vehicle. When the railway vehicle drive system according to Embodiment 2 is used, the railway operator can enjoy the effects according to Embodiment 2, that is, the effects of promptly eliminating slipping or idling, in addition to the effects of Embodiment 1.

[0058] Note that the method according to Embodiment 2 is particularly effective when the propulsion motors 3a and 3b are synchronous motors, but it is not intended to prevent the application to induction motors. Even if the propulsion motors 3a and 3b are induction motors, the effects according to Embodiment 2 described above can be enjoyed.

[0059] The configurations shown in the above embodiments are examples, and it is possible to combine them with other known technologies, combine the embodiments with each other, or omit or change part of the configurations without departing from the gist. The following are the aspects of the present disclosure summarized as appendices. [Appendix 1] A motor control device mounted on a railway vehicle for collectively controlling a plurality of propulsion motors that apply driving force to the railway vehicle and other railway vehicles towed by the railway vehicle, wherein the railway vehicle is provided with a continuously variable transmission configured to be capable of continuously changing a transmission ratio, which is a ratio of a motor speed, which is a rotational speed of the propulsion motor, to a wheel speed, which is a speed of a wheel connected to the wheel axle, and is interposed between the propulsion motor and the wheel axle of the railway vehicle. The motor control device performs first control to adjust the transmission ratio commanded to the continuously variable transmission based on wheel diameter information, which is information on the lengths in the radial direction of a plurality of the wheels. A motor control device characterized by the above. [Appendix 2] When performing the first control, the ratio of the transmission ratio is adjusted so that the rotational speeds of the plurality of propulsion motors become the same. The motor control device according to Appendix 1, characterized by the above. [Appendix 3] The wheel diameter information is held by the motor control device. The motor control device according to Appendix 1 or 2, characterized by the above. [Appendix 4] The railway vehicle is equipped with a train information management device for managing train information of a train formed by a plurality of railway vehicles, and the wheel diameter information is transmitted from the train information management device to the motor control device and held by the motor control device. The motor control device according to any one of Appendices 1 to 3, characterized by the above. [Appendix 5] The propulsion motor is provided with a speed detector for detecting the rotational speed of the propulsion motor. Based on the detection value of the speed detector, the phase difference of the rotor position of the propulsion motor is calculated. Second control is performed to adjust the transmission ratio based on the phase difference of the rotor position. The motor control device according to any one of Appendices 1 to 4, characterized by the above. [Appendix 6] When the phase difference of the rotor position is greater than a determination threshold value, the second control is performed. In the second control, the transmission ratio of the continuously variable transmission connected to the propulsion motor whose rotor position is fluctuating is adjusted. The motor control device according to Appendix 5, characterized by the above. [Appendix 7] When the phase difference of the rotor position drops below the determination threshold value, the control returns to the first control. The motor control device according to Appendix 6, characterized by the above. [Appendix 8] Mounted on a railway vehicle, a plurality of propulsion motors that apply driving force to the railway vehicle and other railway vehicles towed by the railway vehicle; A motor control device that collectively controls the plurality of propulsion motors; A continuously variable transmission device that is interposed between the propulsion motor and the wheel axle of the railway vehicle and is configured to be able to change the transmission ratio, which is the ratio of the motor speed, which is the rotational speed of the propulsion motor, to the wheel speed, which is the speed of the wheel connected to the wheel axle; Comprising; The motor control device performs first control to adjust the transmission ratio commanded to the continuously variable transmission device based on wheel diameter information, which is information on the length in the radial direction of the wheel. A railway vehicle drive system characterized by the above. [Appendix 9] When the motor control device performs the first control, it adjusts the ratio of the transmission ratio so that the rotational speeds of the plurality of propulsion motors become the same. The railway vehicle drive system according to Appendix 8, characterized by the above. [Appendix 10] The wheel diameter information is held by the motor control device. The railway vehicle drive system according to Appendix 8 or 9, characterized by the above. [Appendix 11] The railway vehicle is equipped with a train information management device that manages train information of a train formed by a plurality of railway vehicles, and the wheel diameter information is transmitted from the train information management device to the motor control device and held by the motor control device. The railway vehicle drive system according to any one of Appendices 8 to 10, characterized by the above. [Appendix 12] The railway vehicle is equipped with a transmission ratio command device that receives information regarding the command value of the transmission ratio output from the motor control device. The transmission ratio command device commands the continuously variable transmission device with the received command value of the transmission ratio. The railway vehicle drive system according to any one of Appendices 8 to 11, characterized by the above. [Appendix 13] The propulsion motor is provided with a speed detector that detects the rotational speed of the propulsion motor. The motor control device calculates the phase difference of the rotor position of the propulsion motor based on the detection value of the speed detector, and performs second control to adjust the transmission ratio based on the phase difference of the rotor position. The railway vehicle drive system according to any one of Appendices 8 to 12, characterized by the above. [Appendix 14] The motor control device performs the second control when the phase difference of the rotor position is greater than the determination threshold value. In the second control, the transmission ratio of the continuously variable transmission device connected to the propulsion motor whose rotor position is fluctuating is adjusted. The railway vehicle drive system according to appended note 13, characterized by the above. [Appended note 15] When the phase difference of the rotor position drops below a determination threshold value, the motor control device returns to the first control. The railway vehicle drive system according to appended note 14, characterized by the above.

Explanation of Symbols

[0060] 2a, 2b Opening / closing part, 3, 3a, 3b Propulsion motor, 4a, 4b Joint, 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 Axle, 22a, 22b Rotating shaft, 24, 24a, 24b Pinion shaft, 26, 26a, 26b Continuously variable transmission, 30 Carriage, 32 Carriage frame, 100 Railway vehicle drive system, 300 Processor, 302 Memory, 303 Processing circuit, 304 Interface.

Claims

1. A motor control device mounted on a bogie of a railway vehicle, for collectively controlling a plurality of propulsion motors that apply driving force to the railway vehicle and other railway vehicles towed by the railway vehicle, wherein only the propulsion motors are connected to the gear device of the bogie, and only the propulsion motors apply the driving force, the gear device includes a continuously variable transmission configured to be able to continuously change a transmission ratio, which is a ratio of a motor speed, which is a rotational speed of the propulsion motor, to a wheel speed, which is a speed of a wheel connected to the wheel axle, and is interposed between the propulsion motor and the wheel axle of the railway vehicle, the motor control device performs first control to adjust the transmission ratio commanded to the continuously variable transmission based on wheel diameter information, which is information on the lengths in the radial direction of a plurality of the wheels, characterized in that it is a motor control device.

2. When performing the first control, the ratio of the transmission ratio is adjusted so that the rotational speeds of the plurality of propulsion motors become the same. The motor control device according to claim 1, characterized in that.

3. The wheel diameter information is held by the motor control device. The motor control device according to claim 1, characterized in that.

4. The railway vehicle is equipped with a train information management device that manages train information of a train formed by a plurality of railway vehicles, and the wheel diameter information is transmitted from the train information management device to the motor control device and held by the motor control device. The motor control device according to claim 1, characterized in that.

5. The propulsion motor is provided with a speed detector that detects the rotational speed of the propulsion motor, based on the detected value of the speed detector, calculates a phase difference in the rotor position of the propulsion motor, and performs second control to adjust the transmission ratio based on the phase difference in the rotor position. The motor control device according to any one of claims 1 to 4, characterized in that.

6. When the phase difference in the rotor position is greater than a determination threshold value, the second control is performed, in the second control, the transmission ratio of the continuously variable transmission connected to the propulsion motor whose rotor position is fluctuating is adjusted. The motor control device according to claim 5, characterized in that.

7. When the phase difference in the rotor position drops below the determination threshold value, it returns to the first control. The motor control device according to claim 6, characterized in that.

8. Mounted on a bogie of a railway vehicle, a plurality of propulsion motors that apply driving force to the railway vehicle and other railway vehicles towed by the railway vehicle; A motor control device that collectively controls the plurality of propulsion motors; An infinitely variable transmission device that is interposed between the propulsion motor and the wheel axle of the railway vehicle and is configured to be able to change a gear ratio that is the ratio of the motor speed, which is the rotational speed of the propulsion motor, to the wheel speed, which is the speed of the wheel connected to the wheel axle; Comprising; Only the propulsion motor is connected to the gear device of the bogie, and only the propulsion motor applies the driving force; The motor control device performs first control to adjust the gear ratio commanded to the infinitely variable transmission device based on wheel diameter information, which is information on the length in the radial direction of the wheel; A railway vehicle drive system characterized by the above.

9. When the motor control device performs the first control, the motor control device adjusts the ratio of the gear ratio so that the rotational speeds of the plurality of propulsion motors become the same. The railway vehicle drive system according to claim 8, characterized by the above.

10. The wheel diameter information is held by the motor control device. The railway vehicle drive system according to claim 8, characterized by the above.

11. On the railway vehicle, a train information management device for managing train information of a train composed of a plurality of railway vehicles is mounted, and the wheel diameter information is transmitted from the train information management device to the motor control device and held by the motor control device. The railway vehicle drive system according to claim 8, characterized by the above.

12. On the railway vehicle, a gear ratio command device that receives information regarding the command value of the gear ratio output from the motor control device is mounted. The gear ratio command device commands the received command value of the gear ratio to the infinitely variable transmission device. The railway vehicle drive system according to claim 8, characterized by the above.

13. The propulsion motor is provided with a speed detector that detects the rotational speed of the propulsion motor. The motor control device calculates the phase difference of the rotor position of the propulsion motor based on the detection value of the speed detector, and performs second control to adjust the gear ratio based on the phase difference of the rotor position. The railway vehicle drive system according to any one of claims 8 to 12, characterized by the above.

14. When the phase difference of the rotor position is greater than a determination threshold value, the motor control device performs the second control, and in the second control, the gear ratio of the stepless transmission connected to the propulsion motor whose rotor position is fluctuating is adjusted. The railway vehicle drive system according to claim 13, characterized in that.

15. When the phase difference of the rotor position drops below the determination threshold value, the motor control device returns to the first control. The railway vehicle drive system according to claim 14, characterized in that.

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