On-vehicle device, railway vehicle, control method, and ground device

Abstract

An on-vehicle device that controls a plurality of power conversion devices 10 for converting power from a catenary 1, which is a power source, and supplying the power to an electric motor 5 that drives a vehicle 3, the on-vehicle device comprising: a calculation unit that determines a tread force required for moving the vehicle 3; and a selection unit that selects, on the basis of the tread force, a speed of the vehicle 3, and a voltage value of the catenary 1, a power conversion device to be operated from among the plurality of power conversion devices 10. Through this feature, it is possible to provide an on-vehicle device, a railway vehicle, and a control method capable of further increasing an efficiency of an electrical component provided to the vehicle and improving an energy-saving performance as compared with a case in which the configuration of the present invention is not provided. Further, it is possible to provide a ground device capable of making corrections, even if a design value or an actual measurement value of efficiency of an electric component of a vehicle deviates from the efficiency during actual travel of the vehicle.

Description

On-vehicle device, railway vehicle, control method, and ground device

[0001] The present invention relates to an on-vehicle device, a railway vehicle, a control method, and a ground device. In particular, the present invention relates to an on-vehicle device that controls a power conversion device mounted on a running vehicle, etc.

[0002] For example, in response to global warming, improvement of the energy efficiency of industrial and infrastructure equipment is required. Railways (hereinafter referred to as trains) that run using power supplied via overhead lines, etc., may be equipped with a regenerative power brake that converts the kinetic energy of the vehicle during braking into electricity. Since the regenerative energy generated by the regenerative power brake can be used as the driving energy of other vehicles via the overhead line, trains have high energy-efficient mobility. Electric power conversion devices and electric motors are mounted as electrical equipment to drive the vehicle, such as for propulsion and regeneration. These electrical equipment are controlled to output a desired tread force (or torque) in response to the driver's driving command. To improve the energy efficiency of the vehicle, it is effective to operate the electrical equipment with high efficiency.

[0003] Patent Document 1 discloses a train control system including a plurality of main electric motors that generate power for the running of a train, a drive unit that drives the plurality of main electric motors, and a main control device capable of transmitting control information to the drive unit. The main control device determines the number of main electric motors to be operated based on the current speed of the train and the torque currently required for the train, and generates a torque command for evenly distributing the torque to the determined number of main electric motors among the plurality of main electric motors.

[0004] International Publication No. 2019 / 107016

[0005] However, the efficiency of electrical equipment changes according to the overhead line voltage, and the voltage obtained from the overhead line, etc., fluctuates depending on the behavior of the vehicle. Conventional technology does not take into account the effect of the overhead line voltage, and in some cases electrical equipment cannot operate at its most efficient point, making it difficult to control the electrical equipment at its most efficient point according to the vehicle's running conditions. The present invention aims to provide an on-board device, a railway vehicle, and a control method that can increase the efficiency of electrical equipment installed in a vehicle and improve energy-saving performance compared to a system without the configuration of the present invention. It also aims to provide a ground device that can correct discrepancies between the design value and measured value of the efficiency of the vehicle's electrical equipment and the efficiency during actual vehicle operation.

[0006] To solve the above problems, the present invention provides an on-board device for controlling a plurality of power converters that convert power from a power source and supply it to an electric motor that drives a vehicle, comprising: a calculation unit that determines the tread force required to move the vehicle; and a selection unit that selects a power converter to operate from among the plurality of power converters based on the tread force, the vehicle speed, and the voltage value of the power source. In this case, compared to a case without the above configuration, the efficiency of the electrical equipment installed in the vehicle can be made higher, and an on-board device that can improve energy saving performance can be provided.

[0007] Here, for example, the selection unit determines the optimal number of power converters to operate based on the relationship between the tread force, vehicle speed, and power source voltage value and the efficiency of at least one of the motor and power converter, and selects the power converters to operate from among multiple power converters based on the number of operating units. In this case, the efficiency of the electrical components can be determined with accuracy, and the number of operating power converters can be determined. Alternatively, for example, the selection unit may use a map that associates the tread force, vehicle speed, and efficiency with the power source voltage value. In this case, it becomes easier to determine the optimal number of operating power converters. Furthermore, for example, the selection unit may exclude operating units in the map where the tread force per power converter, corresponding to the vehicle speed and power source voltage value, exceeds the vehicle's adhesion performance, and then determine the optimal number of operating power converters. In this case, operating units that cannot be adopted from the standpoint of vehicle adhesion performance can be removed in advance. Furthermore, for example, the selection unit selects multiple power converters in rotation based on the number of operations, or selects a power converter that operates at the lowest temperature among the electrical components, including the power converter. In this case, the lifespan of the electrical components can be leveled out. Then, for example, the calculation unit calculates the tread force based on the vehicle's driving command, vehicle speed, load-sensitive signal detected by the load-sensitive device, and the voltage value of the power source. In this case, the tread force can be calculated with greater accuracy. Also, for example, efficiency is determined by the ground equipment based on actual vehicle driving data and acquired by the on-board equipment. In this case, it becomes possible to control the system at a high-efficiency point, taking into account variations in efficiency due to manufacturing variations of electrical components and changes in efficiency due to the deterioration of electrical components.

[0008] Furthermore, the present invention relates to a railway vehicle, specifically a railway vehicle equipped with the above-mentioned on-board device. In this case, compared to a vehicle without the above configuration, the efficiency of the electrical equipment installed in the vehicle can be increased, and a railway vehicle with improved energy-saving performance can be provided.

[0009] Furthermore, the present invention relates to a control method for controlling a plurality of power converters that convert power from a power source and supply it to an electric motor that drives a vehicle. The control method involves a processor executing a program stored in memory to determine the tread force required to move the vehicle, and selecting a power converter to operate from among the plurality of power converters based on the tread force, the vehicle speed, and the voltage value of the power source. In this case, compared to a case without the above configuration, the efficiency of the electrical components installed in the vehicle can be increased, and a control method that can improve energy saving performance can be provided.

[0010] Here, for example, the number of power converters that operate most efficiently is determined from the relationship between the tread force, vehicle speed, and power source voltage value and the efficiency of at least one of the motor and power converter, and the number of power converters to operate is selected from among multiple power converters based on the number of operations. In this case, the efficiency of electrical components can be determined with high accuracy. Alternatively, for example, a map is used that associates tread force and efficiency with the power source voltage value. In this case, it becomes easier to determine the number of power converters that operate most efficiently. Furthermore, for example, in the map, the number of operations where the tread force per power converter, corresponding to the vehicle speed and power source voltage value, exceeds the vehicle's adhesion performance is excluded, and then the number of power converters that operate most efficiently is determined. In this case, the number of operations that cannot be adopted from the perspective of vehicle adhesion performance can be removed in advance. Moreover, for example, based on the number of operations, multiple power converters can be selected in rotation, or power converters that operate with lower temperatures among electrical components including power converters can be selected. In this case, the degree of degradation of power converters can be made more uniform. For example, the tread force is determined based on the vehicle's driving command, vehicle speed, load-sensitive signal detected by the load-sensitive device, and the voltage value of the power source. In this case, the tread force can be determined with greater accuracy. Also, for example, efficiency is determined by ground equipment based on actual vehicle driving data and acquired by on-board equipment. In this case, it becomes possible to control the system at a high-efficiency point, taking into account variations in efficiency due to manufacturing variations of electrical components and changes in efficiency due to the deterioration of electrical components.

[0011] Furthermore, the present invention provides a ground device that receives data from actual vehicle driving from an on-board device that controls multiple power conversion devices that convert power from a power source and supply it to an electric motor that drives the vehicle, creates a map based on the actual driving data that correlates the voltage value of the power source with the tread force, vehicle speed, and efficiency, and sends the map to the vehicle. In this case, the ground device can provide correction even if the design value or measured value of the efficiency of the vehicle's electrical components deviates from the efficiency during actual vehicle driving.

[0012] According to the present invention, it is possible to provide an on-board device, a railway vehicle, and a control method that can increase the efficiency of electrical components installed in a vehicle and improve energy-saving performance compared to cases where the configuration of the present invention is not provided. Furthermore, it is possible to provide a ground device that can correct for discrepancies between the design value and measured value of the efficiency of the vehicle's electrical components and the efficiency during actual vehicle operation.

[0013] This is a schematic diagram of an on-board system according to Embodiment 1 of the present invention. This is an example of a circuit diagram of a power converter according to Embodiment 1 of the present invention. This is an example of the efficiency characteristics of an electrical component described in Embodiment 1 of the present invention. This is a control block diagram of a vehicle information control device described in Embodiment 1 of the present invention. This is a control flowchart of a selection processing unit described in Embodiment 1 of the present invention. (a) to (b) are processing methods of the selection processing unit using the efficiency map of an electrical component described in Embodiment 1 of the present invention. This is a diagram showing another case of processing method of the selection processing unit using the efficiency map of an electrical component. This is a control block diagram of processing to update the efficiency characteristics of an electrical component as described in Embodiment 2 of the present invention.

[0014] The embodiments of the present invention will be described in detail below with reference to the attached drawings. The present invention will be described below with reference to Examples 1 and 2.

[0015] <Explanation of the overall configuration of the on-board system> Figure 1 is a schematic diagram of an on-board system 30 according to Embodiment 1 of the present invention. As shown in Figure 1, the vehicle 3 is, for example, a railway vehicle that runs on rails 2. The vehicle 3 receives power from an overhead line 1, which is a power source, via a current collector 4, and converts electrical energy into mechanical energy to rotate the wheels 7 and move forward or backward. A circuit breaker 8, a filter reactor 9, a power converter 10, and an electric motor 5 are mounted on the vehicle 3 as electrical equipment that converts electrical energy into mechanical energy to drive the vehicle 3.

[0016] The power converter 10 converts power from the overhead line 1 and supplies it to the electric motor 5 that drives the vehicle 3. The power converter 10 is controlled based on signals output from the vehicle information control device 11, which is an example of an on-board device, and signals indicating the status of the power converter 10 are uploaded to the vehicle information control device 11. The vehicle information control device 11 is also wirelessly connected to the ground system 31, and uploads its internal data to the ground system 31. The ground system 31 has the function of analyzing and optimizing the uploaded data and distributing the optimization results to the vehicle information control device 11.

[0017] The electrical components shown in Figure 1, namely the circuit breaker 8, filter reactor 9, and power converter 10, are each described in separate boxes. However, the mounting density can be increased by housing some or all of the electrical components in a single box. The rail 2 also serves as the electrical ground. The electric motor 5 is mounted on the bogie 6, which supports the vehicle 3. The electric motor 5 may be either an induction motor or a permanent magnet synchronous motor. In the case of an induction motor, one power converter 10 can drive multiple motors 5. On the other hand, in the case of a synchronous motor, only one motor 5 can be driven by one power converter 10.

[0018] Figure 2 is an example of a circuit diagram of a power converter 10 according to Embodiment 1 of the present invention. In this embodiment, the power converter 10 is configured as an integrated unit of four power converters 10a, 10b, 10c, and 10d. However, it is not limited to this configuration, and each power converter may be configured individually. Here, motors 5a, 5b, 5c, and 5d are connected to the power converters 10a, 10b, 10c, and 10d, respectively. However, it is not limited to this configuration, and for example, multiple motors 5 may be connected to a single power converter 10a. The same applies to power converters 10b, 10c, and 10d.

[0019] In this embodiment, the power converter 10a is supplied with power from the overhead line 1 received by the current collector 4 via a circuit breaker 8a and a filter reactor 9a. Similarly, the power converter 10b is supplied with this power via a circuit breaker 8a and a filter reactor 9b. Likewise, the power converter 10c is supplied with this power via a circuit breaker 8a and a filter reactor 9c, and the power converter 10d is supplied with this power via a circuit breaker 8a and a filter reactor 9d. A charging circuit consisting of contactors 201a, 201b and a charging resistor 202a is mounted between the circuit breaker 8a and the filter reactors 9a and 9b. Likewise, a charging circuit consisting of contactors 201c, 201d and a charging resistor 202b is mounted between the circuit breaker 8a and the filter reactors 9c and 9d. These charging circuits may be mounted in a separate enclosure from the power converter 10, and the circuit breaker 8 and filter reactor 9 may be housed in the same enclosure as the power converter 10. In this embodiment, one charging circuit is connected to two power converters, and one filter reactor 9a is connected to one power converter, but the number of charging circuits and filter reactors may be increased or decreased.

[0020] The power converters 10a to 10d have the function of converting the DC power received by the current collector 4 into AC power. The power converters 10a to 10d all have the same configuration. Below, the power converter 10a will be described as an example. The power converter 10a is composed of a filter capacitor 203, switching elements Q1 to Q6, antiparallel diodes D1 to D6, and a control unit 204. The switching elements Q1-Q2 are connected in series to form the U phase. Similarly, the switching elements Q3-Q4 are connected in series to form the V phase. Similarly, the switching elements Q5-Q6 are connected in series to form the W phase. In this embodiment, the power converter 10 is described as a two-level circuit configuration as an example, but it can also be applied to multi-level circuit configurations of three levels or more.

[0021] The switching elements Q1 to Q6 are semiconductor elements that can switch between ON and OFF states, and their switching is controlled according to the gate signal input from the control unit 204. The switching elements Q1 to Q6 are composed of, for example, IGBTs (Insulated Gate Bipolar Transistors) or MOSFETs (Metal Oxide Semiconductor Field Effect Transistors). When the switching elements Q1 to Q6 are IGBTs, antiparallel freewheeling diodes (hereinafter also simply referred to as "diodes") D1 to D6 are required, connected antiparallel to the main terminals of each switching element. Diodes D1 to D6 allow freewheeling current to flow when each switching element Q1 to Q6 is OFF.

[0022] In contrast, if the switching elements Q1 to Q6 are MOSFETs, the body diodes of the MOSFETs may be used as diodes D1 to D6. Thus, if the switching elements Q1 to Q6 are MOSFETs or the like and have body diodes, the diodes of the MOSFETs may be used instead of connecting diodes in antiparallel to each switching element Q1 to Q6. By using the body diodes as recirculating diodes, the number of diodes D1 to D6 can be reduced, and the power conversion device 10a can be miniaturized.

[0023] Furthermore, two switching elements connected in series (for example, Q1 and Q2) may be housed in the same package, forming a 2-in-1 package. Switching elements Q1 to Q6 can be MOSFETs, IGBTs, or multi-gate IGBTs. The semiconductor materials for switching elements Q1 to Q6 and diodes D1 to D6 can be Si (silicon) or semiconductors with a wider bandgap than Si, such as SiC (silicon carbide) or GaN (gallium nitride). These wide-bandgap semiconductors can reduce power loss compared to Si, thus enabling miniaturization of the power conversion device 10a.

[0024] The power converter 10a applies gate voltages to switching elements Q1 to Q6 via a gate drive circuit (not shown) in response to a gate signal output from the control unit 204. By controlling the ON and OFF states of the switching elements Q1 to Q6 in this way, pulsed AC power is output via the filter capacitor 203. This AC power is supplied to the electric motor 5, and the electrical energy is converted into mechanical energy, causing the vehicle 3 to accelerate or regenerate, move forward or backward. The filter capacitor 203 is connected in parallel with the switching elements Q1 to Q6. The voltages of the overhead line 1 and the filter capacitor 203 are detected using voltage sensors 205a and 205b, respectively. Both voltage sensors 205a and 205b can detect the voltage of the overhead line 1, which is the power source. In this case, if the voltage of the overhead line 1 is detected directly by the voltage sensor 205a, there is the advantage that the installation of the voltage sensor 205a is easy and the voltage detection is easy. On the other hand, when the voltage of the filter capacitor 203 is detected by the voltage sensor 205b, there is an advantage in that a more accurate value can be detected as the voltage applied to the power converter 10a. In this case, the filter capacitor 203 is an example of a capacitor provided in the power converter 10. The U-phase, V-phase, and W-phase currents of the motor 5 are detected using current sensors 206a to 206c. The current sensors may detect any two of the U-phase, V-phase, and W-phase, and the remaining phase may be calculated from the detected two-phase currents. The gate signals that control the ON or OFF state of the switching elements Q1 to Q6 are generated in the control unit 204 based on commands from the vehicle information control device 11 and the voltage of the filter capacitor 203 and the current of the motor 5.

[0025] When the vehicle 3 is being powered, the power converter 10 performs DC-AC power conversion by switching elements Q1 to Q6, converting the DC power supplied from the overhead line 1 into three-phase AC power. The obtained AC power is then output to the motor 5 to drive the motor 5. On the other hand, when the vehicle 3 is decelerating and the regenerative brake is activated, the vehicle 3 enters a regenerative driving state, the motor 5 becomes a generator and outputs three-phase AC power. At this time, the power converter 10 performs AC-DC power conversion using switching elements Q1 to Q6 and diodes D1 to D6, converting the three-phase AC power output from the motor 5 into DC power. The obtained DC power is then output to the overhead line 1 via the current collector 4, thereby supplying regenerative current to other powered vehicles via the overhead line 1.

[0026] Figure 3 shows an example of the efficiency characteristics of an electrical component described in Embodiment 1 of the present invention. Figure 3 shows the efficiency characteristics based on the relationship between tread force and efficiency at a specific speed, for example, 60 km / h. Here, tread force is on the vertical axis and efficiency is on the horizontal axis. Here, the efficiency characteristics are shown for a low voltage of the overhead line 1 (overhead line voltage), for example, 1200V, and a high voltage, for example, 1800V. Note that the vertical and horizontal axes may be inverted, and tread force may be torque. Also, instead of the overhead line voltage measured by the voltage sensor 205a, the voltage of the filter capacitor 203 measured by the voltage sensor 205b may be used. Here, efficiency is defined as the efficiency of the electrical components located between the overhead line 1 and the motor 5, and the main electrical components are the filter reactor 9, the power converter 10, and the motor 5. Among these electrical components, the motor 5 often has a high loss ratio. That is, the efficiency characteristics in Figure 3 are most greatly influenced by the efficiency of the motor 5. Next, the power converter 10 has a high loss ratio. The electrical losses of the electric motor 5 can be broadly classified into three types: copper loss, iron loss, and harmonic losses resulting from the switching operation of the power converter 10. These losses change depending on the overhead line voltage, even at specific speeds and tread forces. For example, copper loss often decreases as the motor current decreases, and iron loss often decreases as the motor voltage decreases. For instance, when the tread force is low, such as F1, the proportion of copper loss is small due to the low motor current, and iron loss becomes dominant. Since iron loss decreases as the motor voltage, i.e., the overhead line voltage, decreases, efficiency is higher when the overhead line voltage is low, when the tread force is F1. In this case, the efficiency reaches its maximum value of η1 when the tread force is F1. On the other hand, when the tread force is high, such as F2, the proportion of copper loss increases as the motor current increases, and the proportion of iron loss decreases. Since the motor current can be reduced as the overhead line voltage increases, efficiency is higher when the overhead line voltage is high, when the tread force is F2. In this case, the efficiency reaches its maximum value of η2 when the tread force is F2. Thus, the efficiency of electrical equipment changes sequentially according to the running conditions of the vehicle 3, such as speed, tread force, and overhead line voltage. Therefore, in order to save energy, it is necessary for the equipment to operate at a more efficient point according to the overhead line voltage.

[0027] <Detailed Description of Vehicle Information Control Device 11> Figure 4 is a control block diagram of the vehicle information control device 11 described in Embodiment 1 of the present invention. The vehicle information control device 11 has a basic tread force calculation unit 405 that calculates the basic tread force based on driving commands such as notches output from the driver's cab 401, the speed of the vehicle 3 detected by the speed sensor 402, the load-sensitive signal detected by the load-sensitive device 403, and the voltage value acquired by the voltage sensor 404. In this case, the basic tread force calculation unit 405 functions as a calculation unit that determines the tread force required to move the vehicle 3. With this configuration, the tread force can be determined with greater accuracy. Furthermore, the vehicle information control device 11 has a selection processing unit 406 that calculates commands for operation or non-operation of each power converter 10a to 10d, and the tread force when the power converter is operating, based on the basic tread force calculated by the basic tread force calculation unit 405, the speed detected by the speed sensor 402, the load-sensitive signal detected by the load-sensitive device 403, and the voltage value acquired by the voltage sensor 404. In this case, the selection processing unit 406 functions as a selection unit that selects which power converter to operate from among the multiple power converters 10a to 10d based on the tread force, the speed of the vehicle 3, and the voltage value of the power source. The vehicle information control device 11 also has the function of collecting and storing data from the power converters 10a to 10d. The basic tread force calculation unit 405 calculates the basic tread force necessary to run according to the driving command based on the driving command, speed, load response signal, and voltage value. Here, the basic tread force to be calculated may be the value for the entire train, or the train may be divided into several units and the tread force per unit may be calculated. The selection processing unit 406 performs a selection process for the power converters 10a to 10d so that the electrical equipment operates at a high efficiency while satisfying the basic tread force necessary for the running of the vehicle 3, and outputs an operation or non-operation command and a tread force command when operating to the power converters. The contents of the selection processing unit 406 will be described in detail below.

[0028] <Detailed Description of Selection Processing Unit 406> Figure 5 is a control flowchart of the selection processing unit 406 described in Embodiment 1 of the present invention. Step 500 starts this flowchart. Step 501 reads the basic tread force. The basic tread force is the result calculated by the basic tread force calculation unit 405 in Figure 4, for example, 100kN. Step 502 detects the current overhead line voltage using a voltage sensor. Here, the voltage to be detected is not the voltage of the overhead line 1 measured by the voltage sensor 205a, but may also be the voltage of the filter capacitor 203 inside the power converter 10 measured by the voltage sensor 205. The detected value is, for example, 1500V. Step 503 reads the efficiency map of the electrical equipment at the detected voltage. The efficiency map is, for example, a map of the efficiency of the electrical equipment at each speed and tread force, with the horizontal axis being speed and the vertical axis being tread force. This efficiency map is stored as a database in the internal memory (not shown) of the vehicle information control device 11 for each voltage of the overhead line 1 or the voltage of the filter capacitor 203. Furthermore, the finer the resolution of the overhead line voltage, speed, and tread force in the database, the better the efficiency resolution of the electrical equipment, thus improving the energy-saving effect in Embodiment 1 of the present invention. In step 504, the current speed of the vehicle 3 is detected. In step 505, the tread force for each number of operating power converters is calculated for the detected speed, and the efficiency of the electrical equipment at the calculated tread force is extracted from the efficiency map. In step 506, points of excessive adhesion are excluded. Specifically, reducing the number of operating power converters increases the tread force per unit, which improves the efficiency of the electrical equipment. However, if the tread force per unit exceeds the adhesion performance, there is a problem in that the wheels 7 will slip. Therefore, the number of operating power converters that results in a tread force higher than the tread force that satisfies the adhesion performance is excluded. In this way, it is possible to calculate the number of operating electrical equipment that can be controlled at a highly efficient point while preventing wheel slippage. In step 507, the number of operating power converters with the highest efficiency among those excluded in step 506 and the tread force at that time are output. The following explains how to process the data on the efficiency map. Step 508 marks the end of this flowchart.

[0029] Figures 6(a) and 6(b) show the processing method of the selection processing unit 406 using the efficiency map of the electrical equipment described in Embodiment 1 of the present invention. In Figure 6(a), the efficiency map is shown, with speed on the horizontal axis and tread force on the vertical axis, mapping the efficiency at each speed and tread force. The efficiency map is represented as contour lines, but the efficiency values ​​at each speed and tread force may be stored in a database. This efficiency map is for the case where the detected overhead line voltage is 1500V, and the selection processing unit 406 reads this efficiency map as shown in step 503 of Figure 5.

[0030] Next, the selection processing unit 406 plots the basic tread force calculated by the basic tread force calculation unit 405, for example 60 kN, parallel to the x-axis, and plots the current speed of the vehicle 3, for example 50 km / h, parallel to the y-axis. Next, the selection processing unit 406 calculates the tread force per power converter according to the number of power converters operating relative to the basic tread force. For example, if the basic tread force is 60 kN and the number of operating power converters N is 2, then 30 kN per power converter is the tread force required for the vehicle 3 to run. If the number of operating power converters N is 3, then 20 kN per power converter is the tread force required for the vehicle 3 to run.

[0031] Next, the selection processing unit 406 eliminates points where the tread force exceeds the adhesion performance. For example, if the tread force required to satisfy the desired adhesion performance without the wheels 7 of vehicle 3 slipping is 25 kN per power converter, then points where the tread force per electrical component exceeds 25 kN are eliminated. In Figure 6(a), points where the number of operating power converters N is 1 and 2 are eliminated. In Figure 6(b), this process is represented by an × indicating the adhesion limit when the number of operating components N is 1 and 2. Note that the upper limit of the tread force per power converter, which is determined from the adhesion performance, may be changed depending on the speed of vehicle 3, weather conditions, etc. For example, 30 kN in sunny weather and 10 kN in rainy weather. In rainy weather, the adhesion performance is lower than in sunny weather, so in order to prevent the wheels 7 from slipping, it is necessary to lower the upper limit of the tread force per power converter. By considering the weather in this way, it is possible to ensure the running performance of vehicle 3 while operating the electrical components at a highly efficient point. Furthermore, since adhesion performance generally decreases with increasing speed, the upper limit of the tread force per power converter may be changed according to the speed, for example, to 25 kN at a speed of 50 km / h and 15 kN at a speed of 100 km / h.

[0032] Next, the selection processing unit 406 selects the point with the highest efficiency while satisfying the upper limit of the tread force considering the adhesion performance. For the speed of the vehicle 3 and the tread force for each number of operating power converters, the efficiency is extracted from the efficiency map shown in Figure 6(a). For example, if the speed is 50 km / h, the number of operating power converters N is 3, and the tread force per power converter is 20 kN, the efficiency of the power converters is extracted as 87%. The number of operating power converters with the highest efficiency among the extracted efficiencies and the corresponding tread force are output to the power converters. For example, in Figure 6(a), the highest efficiency is 92% when the number of operating power converters is 4 (N=4) and the tread force per power converter is 15 kN. In Figure 6(b), this process is represented by the operating point determination being marked as ○ for the case where the number of operating units N is 4. Therefore, 15 kN is output as a tread force command value to 4 of the power converters 10 installed in the vehicle 3. The power converters other than the four units will receive a command to remain inactive. In this way, the vehicle 3's driving performance can be ensured while the electrical components can be operated at their most efficient point, thereby achieving energy savings. Furthermore, it is conceivable that the lifespan of the operating power converters can be leveled out by selecting them on a rotational basis. In addition, by selecting power converters that operate at the lowest temperature among the electrical components, including the power converters themselves, energy savings through increased efficiency can be further promoted.

[0033] Figure 7 shows another case of the processing method of the selection processing unit 406 on the efficiency map of electrical equipment. Figure 7 shows the efficiency map when the overhead line voltage is 1800V. In this case as well, the selection processing unit 406 determines the number of operating power converters in the same way as explained in Figure 6. In the efficiency map of Figure 7, the efficiency is highest when there are 3 operating power converters (N=4) and the tread force per power converter is 20kN.

[0034] As explained in Figures 6 and 7, the selection processing unit 406 determines the optimal number of power converters to operate based on the relationship between the tread force, the speed of the vehicle 3, the voltage value of the overhead line 1 (the power source), and the efficiency of at least one of the motor 5 and the power converter. Based on this number, it selects which power converters to operate from among the multiple power converters 10. This allows for accurate determination of the efficiency of the electrical components and the number of power converters to operate. In this case, as shown in Figures 6 and 7, the selection processing unit 406 uses a map that associates the voltage value of the overhead line 1 (the power source) with the tread force, the speed of the vehicle 3, and the efficiency. Using this map makes it easier to determine the optimal number of power converters to operate. In this way, the selection processing unit 406 takes into account the effect of the voltage of the overhead line 1 when determining efficiency. As a result, the electrical components can be operated at a high-efficiency point. Furthermore, the selection processing unit 406 excludes the number of power converters in operation on the map where the tread force per power converter, corresponding to the speed of the vehicle 3 and the voltage value of the overhead line 1 which is the power source, exceeds the adhesion performance of the vehicle 3, and then determines the number of power converters in operation that provides the best efficiency. This makes it possible to remove in advance the number of operations that cannot be adopted from the standpoint of the adhesion performance of the vehicle 3.

[0035] In Embodiment 1 of the present invention, the selection processing unit 406 was mounted inside the vehicle information control device 11, but the selection processing unit 406 may also be mounted inside the power converter 10. Furthermore, the selection processing unit 406 may function not only during powering but also during regenerative braking. By functioning during both powering and regeneration, energy saving performance can be improved. According to the vehicle information control device 11 described above, the efficiency of the electrical components installed in the vehicle 3 can be increased, and energy saving performance can be improved.

[0036] Figure 8 is a control block diagram of the process for updating the efficiency characteristics of electrical components, as described in Embodiment 2 of the present invention. In the processing of the selection processing unit 406 described in Embodiment 1 of the present invention, the efficiency map of electrical components is stored as a database. This database stores the design value and measured value of efficiency. These design value and measured value of electrical component efficiency may deviate from the efficiency of the vehicle 3 during actual operation. Possible causes include, for example, manufacturing variations of the electrical components. The power converter 10 uploads its internal data, such as voltage, current, and frequency, to the vehicle information control device 11, and the vehicle information control device 11 distributes this data to the ground system 31, which is a ground device. The ground system 31 calculates the efficiency of the electrical components using not only the distributed data but also the design data of the electrical components, and maps it according to the speed and tread force. The calculated efficiency map of the electrical components is uploaded to the selection processing unit 406 of the vehicle information control device 11, thereby updating the efficiency map of the electrical components.

[0037] Thus, in Embodiment 2, efficiency is determined by the ground system 31 based on actual driving data of the vehicle 3 and acquired by the vehicle information control device 11. The vehicle information control device 11 of Embodiment 2 makes it possible to increase the efficiency of the electrical components installed in the vehicle 3. In addition, it is possible to improve energy saving performance and to control the system at a high-efficiency point that takes into account variations in efficiency due to manufacturing variations of the electrical components and changes in efficiency due to the deterioration of the electrical components.

[0038] In this case, the ground system 31 receives data on the actual running of the vehicle 3 from the vehicle information control device 11, which controls a plurality of power conversion devices 10 that convert power from the overhead line 1, which is the power source, and supply it to the electric motor 5 that drives the vehicle 3. Based on the actual running data, it creates a map that corresponds to the voltage value of the overhead line 1, which is the power source, and associates the tread force, the vehicle speed, and efficiency, and sends the map to the vehicle 3. This makes it possible to provide a ground device that can correct for discrepancies between the design value and the measured value of the efficiency of the vehicle's electrical components and the efficiency during the vehicle's actual running.

[0039] <Explanation of Control Method> The processing performed by the vehicle information control device 11 is realized through the cooperation of software and hardware resources. That is, a processor such as a CPU provided in the vehicle information control device 11 loads a program that realizes each function of the vehicle information control device 11 into the main memory and executes it to realize each of these functions. Therefore, the processing performed by the vehicle information control device 11 described above can be understood as a control method that controls a plurality of power converters 10 that convert power from the overhead line 1, which is the power source, and supply it to the electric motor 5 that drives the vehicle 3. The processor executes a program recorded in memory to determine the tread force required to move the vehicle 3, and based on the tread force, the speed of the vehicle 3, and the voltage value of the overhead line 1, which is the power source, it selects a power converter to operate from among the plurality of power converters 10. As a result, compared to cases where these configurations are not provided, the efficiency of the electrical equipment installed in the vehicle 3 can be increased, and a control method that can improve energy saving performance can be provided.

[0040] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. For example, the embodiments described above are explained in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described. It is also possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations. In addition, some or all of the above configurations, functions, processing units, processing means, etc., may be realized in hardware, for example, by designing them as integrated circuits. In addition, each of the above configurations, functions, etc., may be realized in software by having a processor interpret and execute a program that realizes each function. Information such as programs, tables, files, etc. that realize each function can be stored in memory, a recording device such as a hard disk or SSD (Solid State Drive), or a recording medium such as an IC card, SD card, or DVD. Furthermore, control lines and information lines are shown only if they are considered necessary for explanation, and not all control lines and information lines are necessarily shown in the actual product. In practice, it can be assumed that almost all configurations are interconnected.

[0041] 1...Overhead line, 3...Vehicle, 5...Electric motor, 9...Filter reactor, 10, 10a, 10b, 10c, 10d...Power converter, 11...Vehicle information control device, 31...Ground system, 401...Driver's cab, 402...Speed ​​sensor, 403...Load-sensitive device, 404...Voltage sensor, 405...Basic tread force calculation unit, 406...Selection processing unit

Claims

1. An on-board device for controlling a plurality of power converters that convert power from a power source and supply it to an electric motor that drives a vehicle, comprising: a calculation unit for determining the tread force required to move the vehicle; and a selection unit for selecting a power converter to operate from among the plurality of power converters based on the tread force, the speed of the vehicle, and the voltage value of the power source.

2. The on-board device according to claim 1, wherein the selection unit determines the number of power converters that will be in operation with the best efficiency based on the relationship between the tread force, the vehicle speed, the voltage value of the power source, and the efficiency of at least one of the electric motor and the power converter, and selects the power converters to be operated from among the plurality of power converters based on the number of operations.

3. The on-board device according to claim 2, wherein the selection unit uses a map relating the voltage value of the power source, the tread force, the vehicle speed, and the efficiency as the relationship.

4. The on-board device according to claim 3, wherein the selection unit excludes the number of operations in the map where the tread force of each power converter, corresponding to the vehicle speed and the voltage value of the power source, exceeds the adhesion performance of the vehicle, and then determines the number of power converters that provides the best efficiency.

5. The on-board device according to any one of claims 2 to 4, wherein the selection unit selects the plurality of power converters in rotation based on the number of operating devices, or selects a power converter that operates the one with the lower temperature among the electrical components including the power converter.

6. The on-board device according to any one of claims 2 to 5, wherein the calculation unit determines the tread force based on the driving command of the vehicle, the speed of the vehicle, the load-sensitive signal detected by the load-sensitive device, and the voltage value of the power source.

7. The on-board device according to any one of claims 2 to 6, wherein the efficiency is determined by a ground device based on actual driving data of the vehicle and acquired by the on-board device.

8. The vehicle is a railway vehicle, and is equipped with the on-board device described in any one of claims 1 to 7.

9. A control method for controlling a plurality of power converters that convert power from a power source and supply it to an electric motor that drives a vehicle, the control method comprising: a processor executing a program stored in memory to determine the tread force required to move the vehicle, and selecting a power converter to operate from among the plurality of power converters based on the tread force, the speed of the vehicle, and the voltage value of the power source.

10. The control method according to claim 9, wherein the number of power converters that operate to achieve the best efficiency is determined from the relationship between the tread force, the vehicle speed, the voltage value of the power source, and the efficiency of at least one of the electric motor and the power converter, and the power converters to be operated from among the plurality of power converters based on the number of operations.

11. The control method according to claim 10, which uses a map that associates the tread force with the efficiency, corresponding to the voltage value of the power source.

12. The control method according to claim 11, wherein the number of operations in the map in which the tread force of a power converter per unit, corresponding to the vehicle speed and the voltage value of the power source, exceeds the adhesion performance of the vehicle is excluded, and the number of operations of the power converter that provides the best efficiency is determined.

13. The control method according to any one of claims 10 to 12, wherein, based on the number of operating devices, the plurality of power converters are selected in rotation, or the power converter that operates the one with the lower temperature among the electrical components including the power converter is selected.

14. A control method according to any one of claims 10 to 13, wherein the tread force is determined based on the vehicle's driving command, the vehicle's speed, the load-sensitive signal detected by the load-sensitive device, and the voltage value of the power source.

15. The control method according to any one of claims 10 to 14, wherein the efficiency is determined by a ground device based on actual driving data of the vehicle and acquired by an on-board device.

16. A ground device that receives data of the actual running of the vehicle from an on-board device that controls multiple power conversion devices that convert power from a power source and supply it to an electric motor that drives the vehicle, creates a map based on the actual running data that corresponds to the voltage value of the power source and associates the tread force, the speed and efficiency of the vehicle, and sends the map to the vehicle.

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