JP2012060727A - Motor control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively drive two motors in the entire region, the motors being mounted on a vehicle and having a same rated output.SOLUTION: An ECU 8 of a motor control system 1 includes a memory part 9 and a CPU 10. The memory part 9 stores boundary torques Tx and Ty showing the boundaries of a low torque region, a medium torque region and a high torque region which are preset based on an efficiency as a total of first and second motors 4a and 4b. A determination part 12 of the CPU 10 compares a required torque Tn with the boundaries torque Tx and Ty to determine a region to which a motor rotational frequency N and the required torque Tn belong. A control part 13 of the CPU 10 drives: when the determined region is the low torque region, only the first motor 4a; when the determined region is the medium torque region, the first and second motors while the first motor 4a output the maximum torque; and, when the determined region is the high torque region, the first and second motors equivalently.

Description

  The present invention relates to a motor control device that controls two motors of the same rated output mounted on a vehicle.

  In JP-A-7-143616, when the rotational speeds of two motors attached to two wheels of a moving body change, the two motors are controlled so as to generate respective command torques, and always the same. A motor control device that rotates at an angular velocity is described.

JP-A-7-143616

  However, in the above configuration, since the two motors are controlled without considering the efficiency, they cannot be driven efficiently.

  Accordingly, an object of the present invention is to provide a motor control system that can efficiently drive two motors of the same rated output mounted on a vehicle.

  In order to achieve the above object, a first aspect of the present invention is a motor control system that controls driving of two motors having the same rated output, and includes a first motor, a second motor, a storage unit, and a control unit. Prepare. The first motor and the second motor are motors of the same rated output that output the required torque required for traveling of the vehicle to one drive shaft and have the same motor rotation speed when driving one drive shaft. .

  The storage means includes a plurality of areas defined by the motor speed and torque, a low torque area having a maximum torque corresponding to each motor speed of the first motor as a boundary on the high torque side, and a low torque area. A medium torque region adjacent to the high torque side and a high torque region adjacent to the high torque side of the medium torque region are stored.

  The control means drives the first motor so that all of the required torque is distributed to the first motor when the motor rotation speed and the required torque when the vehicle travels belong to the low torque region, and belongs to the middle torque region. In such a case, the first and the maximum torque of the first motor corresponding to the motor rotation number is distributed to the first motor, and the torque obtained by subtracting the maximum torque of the first motor from the required torque is distributed to the second motor. When the second motor is driven and belongs to the high torque region, the first and second motors are driven so that the required torque is evenly distributed.

  Among the two motors having the same rated output that outputs the desired torque to one drive shaft and the same motor rotation speed when driving one drive shaft, In the torque region where the output torque is less than the maximum torque of one motor as a whole, it is often the case that only one motor is driven, and in the low torque side of the torque region exceeding the maximum torque of one motor, There is a case where two motors are driven in a state where one motor outputs a maximum torque, and there is a characteristic that the case where two motors are driven equally is high on the high torque side in the torque region. .

  In the above configuration, at an arbitrary motor speed, only the first motor is driven in the low torque region where the output torque is equal to or less than the maximum torque of the first motor, and in the middle torque region adjacent to the high torque side of the low torque region. The first and second motors are driven in a state where the first motor outputs the maximum torque, and the first and second motors are equally driven in the high torque region adjacent to the high torque side of the middle torque region. Thus, since the first and second motors are driven in accordance with the above-described efficiency, when the first and second motors have the above-described efficiency characteristics, the entire first and second motors are driven. As a result, the efficiency (total motor efficiency) can be improved.

  In the low torque region, the motor is driven when the first motor is driven so that all the required torque is distributed than when the first and second motors are driven so that the required torque is evenly distributed. The efficiency is high, and in the middle torque range, the maximum torque of the first motor corresponding to the motor speed is distributed to the first motor, and the torque obtained by subtracting the maximum torque of the first motor from the required torque is distributed to the second motor. When the first and second motors are driven, the motor efficiency is higher than when the first and second motors are driven so that the required torque is evenly distributed. When the first and second motors are driven so as to be evenly distributed, the maximum torque of the first motor corresponding to the motor speed is distributed to the first motor, and the maximum torque of the first motor is calculated from the required torque. The may be higher motor efficiency than when driving the first and second motor as the subtracted torque is distributed to the second motor.

  In the above configuration, the torque distribution for driving only the first motor, the torque distribution for driving the first and second motors with the first motor outputting the maximum torque, and the first and second motors are driven equally. Among the torque distributions, the driving of the first and second motors is controlled so that the overall motor efficiency is the highest at an arbitrary motor speed in each of the low torque region, medium torque region, and high torque region. The Therefore, the overall motor efficiency can be further improved.

  A second aspect of the present invention is a motor control system that controls driving of two motors having the same rated output, and includes a first motor, a second motor, storage means, and control means.

  The first motor and the second motor are motors of the same rated output that output the required torque required for traveling of the vehicle to one drive shaft and have the same motor rotation speed when driving one drive shaft. .

  The storage means stores a first region on the low torque side and a second region adjacent to the high torque side of the first region as a plurality of regions defined by the motor speed and torque.

  The control means drives the first motor so that all of the required torque is distributed when the motor rotational speed and the required torque when the vehicle travels belong to the first region, and the motor rotational speed and the required torque when the vehicle travels. When the torque belongs to the second region, the first and second motors are driven so that the required torque is evenly distributed.

  Among the two motors having the same rated output that outputs the desired torque to one drive shaft and the same motor rotation speed when driving one drive shaft, The overall efficiency is high when only one motor is driven in the torque region where the output torque is low, and the two motors are driven equally in the torque region adjacent to the high torque side of the torque region. Some have the characteristic that

  In the above configuration, only the first motor is driven in the first region where the output torque is low at an arbitrary motor rotation speed, and the first and second motors are driven in the second region adjacent to the high torque side of the first region. Driven equally. Thus, since the first and second motors are driven in accordance with the above-described efficiency, when the first and second motors have the above-described efficiency characteristics, the overall motor efficiency is improved. Can do.

  Further, in the first region, when the first motor is driven so that all the required torque is distributed, the motor is more than when the first and second motors are driven so that the required torque is evenly distributed. The efficiency is high, and in the second region, when the first motor is driven so that the required torque is all distributed, the first and second motors are driven so that the required torque is evenly distributed. The first and second motors are driven so that the maximum torque of the first motor corresponding to the motor speed is distributed to the first motor and the torque obtained by subtracting the maximum torque of the first motor from the required torque is distributed to the second motor. The motor efficiency may be higher than when doing so.

  In the above configuration, the torque distribution for driving only the first motor, the torque distribution for driving the first and second motors with the first motor outputting the maximum torque, and the first and second motors are driven equally. Among the torque distributions, in the first and second regions, the driving of the first and second motors is controlled so that the overall motor efficiency becomes the highest at an arbitrary motor speed. Therefore, the overall motor efficiency can be further improved.

  The plurality of regions stored in the storage unit may further include a third region adjacent to the second region on the high torque side. In the third region, the first and the second motors are arranged such that the maximum torque of the first motor corresponding to the motor speed is distributed to the first motor and the torque obtained by subtracting the maximum torque of the first motor from the required torque is distributed to the second motor. The motor efficiency is higher when driving the second motor than when driving the first and second motors so that the required torque is evenly distributed. The control means distributes the maximum torque of the first motor corresponding to the motor rotational speed to the first motor when the motor rotational speed and the required torque when the vehicle travels belong to the third region. The first and second motors are driven so that the torque obtained by subtracting the maximum torque of the motor is distributed to the second motor.

  In the above-described configuration, the first and second motors are driven in a state where the first motor outputs the maximum torque in the third region adjacent to the high torque side of the second region at any motor rotation speed. In the third region, any motor rotation is possible between torque distribution for driving the first and second motors in a state where the first motor outputs maximum torque and torque distribution for driving the first and second motors equally. The drive of the first and second motors is controlled in a torque distribution that increases the overall motor efficiency in number. Therefore, the overall motor efficiency can be further improved.

  According to a third aspect of the present invention, there is provided a motor control device for controlling the driving of one motor divided into two so that the coil windings of the stator can be connected, and comprising a motor, storage means and control means. Have.

  The motor is provided with a stator having the same number of first windings and second windings that are divided so as to be connectable. When the first and second windings are cut off, only the first winding is energized and driven. When the first and second windings are connected, the first and second windings are energized and driven to output the required torque required for vehicle travel.

  The storage means stores, as a plurality of regions defined by the rotation speed and torque of the motor, a low torque side cut-off region and a connection region adjacent to the high torque side of the cut-off region.

  When the rotational speed of the motor during traveling of the vehicle and the required torque belong to the cutoff region, the control means drives the motor by shutting off the first and second windings, and the rotational speed of the motor during traveling of the vehicle When the required torque belongs to the connection region, the first and second windings are connected to drive the motor.

  A stator having two windings of the same number divided so as to be connectable is provided, and when these two windings are cut off, only one winding is energized and driven, and when coupled, the two windings are energized. Among the motors that drive and output a desired torque, the efficiency of the motor at an arbitrary rotational speed is high in the torque region where the output torque is low. Some torque regions adjacent to the torque side have a characteristic that the case where two windings are connected is high.

  In the above configuration, at any motor speed, the first and second windings are cut off in the cut-off region where the output torque is low, and the first and second windings are connected in the connection region adjacent to the high torque side of the cut-off region. Are concatenated. Thus, since the first and second windings are cut off or connected in accordance with the above-described efficiency, when the motor having the first and second windings has the above-described efficiency characteristics, the motor Efficiency can be improved.

  In the cut-off region, the motor efficiency is higher when the first and second windings are cut off and the motor is driven than when the first and second windings are connected and the motor is driven. Then, the motor efficiency may be higher when driving the motor by connecting the first and second windings than when driving the motor by cutting off the first and second windings.

  In the above-described configuration, the motor efficiency at an arbitrary motor rotation speed in the cutoff and connection region among the winding state in which the first and second windings are cut off and the winding state in which the first and second windings are connected. The first and second windings are controlled so that the winding state becomes higher. Therefore, the overall motor efficiency can be further improved.

  According to the present invention, two motors with the same rated output mounted on a vehicle can be driven efficiently. A motor having two equal numbers of windings can also be driven efficiently.

1 is a block configuration diagram schematically showing a motor control system 1 of a first embodiment. It is a figure which shows the motor efficiency as the whole of 1st and 2nd motor 4a, 4b. It is a figure which shows boundary torque Tx and Ty in arbitrary motor rotation speed, a low torque area | region, a middle torque area | region, and a high torque area | region. It is a flowchart which shows a motor control process. It is a figure which shows the motor efficiency as the whole of a 3rd and 4th motor. It is a block block diagram which shows typically the motor control system 1 of 3rd Embodiment.

  Hereinafter, a motor control system according to a first embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the motor control system 1 controls the drive of two motors, and is mounted on the vehicle together with the first motor 4a and the second motor 4b. The motor control system 1 includes a battery 2, a first inverter 3a and a second inverter 3b, a first motor 4a and a second motor 4b, an accelerator opening sensor 6, a rotation speed detection sensor 7, an ECU (Electric Control). Unit) 8.

  The battery 2 stores electric power charged at a charging stand or the like and electric power generated when the first and second motors 4a and 4b are decelerated. The 1st inverter 3a and the 2nd inverter 3b adjust the electric power supplied from the battery 2 to the 1st motor 4a and the 2nd motor 4b according to the control signal from ECU8 mentioned later.

  The first motor 4a and the second motor 4b are motor generators that function as both power generation means and electric means, and include a rotor having a rotating shaft and a stator having a coil. The first and second motors 4a and 4b have the same rated output, and the maximum torque Tmax is, for example, 400 N · m when the rotational speed is zero. The first and second motors 4 a and 4 b are arranged in parallel, and one end is connected to the power coupling unit 5. The power coupling unit 5 includes a drive gear attached to each of the rotation shafts of the first and second motors 4a and 4b, and a driven gear that is driven by the two drive gears and coupled to the propeller shaft 14. The first and second motors 4a and 4b are driven at the same rotational speed. The first and second motors 4a and 4b appropriately share the required torque Tn necessary for traveling of the vehicle and output it. The first motor 4a is driven by electric power supplied from the battery 2 via the first inverter 3a, and outputs a shared torque Ta. The second motor 4b is driven by electric power supplied from the battery 2 via the second inverter 3b, and outputs a shared torque Tb. The shared torques Ta and Tb output from the first and second motors 4 a and 4 b are transmitted to the propeller shaft 14 via the power coupling portion 5. The propeller shaft 14 is connected to the drive wheels 17a and 17b via the differential gear 15 and the axle shafts 16a and 16b, and the drive wheels 17a and 17b are requested torques output from the first motor 4a and the second motor 4b. The vehicle rotates by Tn (Tn = Ta + Tb) and the vehicle travels.

  The accelerator opening detection sensor 6 detects an accelerator pedal depression amount (accelerator opening) A operated by a vehicle driver at predetermined time intervals.

  The rotation speed detection sensor 7 detects the rotation speed (motor rotation speed) N of the first and second motors 4a and 4b at every predetermined time.

  The ECU (Electric Control Unit) 8 includes a storage unit 9 and a CPU (Central Processing Unit) 10.

  The storage unit 9 is configured by a recording medium such as a RAM (Random Access Memory), for example, and stores various programs and various data including a motor control process execution program for the CPU 10 to execute a motor control process. The motor control process execution program includes a boundary torque map, a rotation speed-torque characteristic map, and torque distribution information. In the boundary torque map, boundary torque indicating each boundary of the low torque region, the middle torque region, and the high torque region (plural regions) defined by the motor rotation speed and the output torque of the first and second motors 4a and 4b. Tx and Ty are stored. In the rotation speed-torque characteristic map, a maximum torque Tmax corresponding to an arbitrary motor rotation speed of the first and second motors 4a and 4b is stored. The torque distribution information stores a predetermined arithmetic expression for calculating the torque distribution of the first and second motors 4a and 4b and the shared torques Ta and Tb of the first and second motors 4a and 4b in each region. These two maps and torque distribution information may be stored in the storage unit 9 separately from the motor control processing execution program.

  Here, the low torque region, the medium torque region, and the high torque region will be described with reference to FIGS. The low torque region, the medium torque region, and the high torque region are defined by the motor rotation speed and output torque of the first and second motors 4a and 4b, and the motor efficiency of the first and second motors 4a and 4b as a whole ( The overall motor efficiency when the first and second motors 4a and 4b are driven in two different driving states is set in advance so that the overall motor efficiency is improved in all regions. The two drive states of the first and second motors 4a and 4b are that, at an arbitrary motor speed, only the first motor 4a is driven in the torque region below the maximum torque Tmax of the first motor 4a, and the maximum torque Tmax is set. In the exceeding torque range, the first driving state in which the first motor 4a outputs the maximum torque and the first driving state in which the first motor 4a and 4b are driven, and the entire torque region regardless of the maximum torque Tmax of the first motor 4a. This is a second driving state in which the first and second motors 4a and 4b are driven equally. FIG. 2 is a diagram showing the overall motor efficiency. A curve L1 in FIG. 2 shows the overall motor efficiency when the first and second motors 4a and 4b are driven in the first driving state at 2000 rpm, and a curve L2 shows the first and second motors 4a and 4b. The overall motor efficiency when driven in the second drive state at 2000 rpm is shown. FIG. 3 is a diagram showing boundary torques Tx and Ty corresponding to an arbitrary motor rotation speed, a low torque region, a middle torque region, and a high torque region.

  As shown in FIG. 2, when the first and second motors 4a and 4b are driven in the first and second driving states with the motor rotation speed N set to 2000 rpm, the overall motor efficiency is the output torque. However, in the torque region where the boundary torque Ty is less than or equal to the boundary torque Ty, the first driving state (curve L1) is higher, and in the torque region exceeding the boundary torque Ty, the second driving state (curve L2) is higher. For this reason, the first and second motors 4a and 4b switch the driving state with the boundary torques Tx and Ty, and drive only the first motor 4a in the torque region (low torque region) equal to or lower than the boundary torque Tx. In the torque region (intermediate torque region) from Tx to Ty, the two motors 4a and 4b are driven in a state where the first motor 4a outputs the maximum torque Tmax, and in the torque region (high torque region) exceeding the boundary torque Ty, By driving the first and second motors 4a and 4b equally, they are efficiently driven in the entire region. Accordingly, the low torque region, the middle torque region, and the high torque region are set as regions partitioned by the boundary torques Tx and Ty, and the boundary torques Tx and Ty are stored in the boundary torque map. In addition, although detailed description of these three regions is omitted, an arbitrary motor speed other than 2000 rpm is also set, and boundary torques Tx and Ty corresponding to these arbitrary motor speeds are displayed in the boundary torque map. Remembered. Note that the boundary torques Tx and Ty corresponding to an arbitrary motor rotation speed and the three regions are as shown in FIG.

  The CPU 10 that executes the motor control process functions as the calculation unit 11, the determination unit 12, and the control unit 13.

  The calculation unit 11 includes a first calculation unit and a second calculation unit. The first calculation unit calculates the required torque Tn required for traveling of the vehicle by substituting the accelerator opening A detected by the accelerator opening detection sensor 6 into a predetermined arithmetic expression. The second calculation unit calculates the power necessary for the first and second motors 4a and 4b to output the shared torques Ta and Tb.

  The determination unit 12 determines whether the motor rotation speed N detected by the rotation speed detection sensor 7 and the required torque Tn calculated by the calculation unit 11 (first calculation unit) are any of a low torque region, a medium torque region, and a high torque region. Determine if it belongs to the region. Specifically, the determination unit 12 refers to the boundary torque map stored in the storage unit 9 to acquire and acquire boundary torques Tx and Ty corresponding to the motor rotational speed N detected by the rotational speed detection sensor 7. The region is determined by comparing the boundary torques Tx and Ty thus obtained with the required torque Tn calculated by the calculation unit 11 (first calculation unit). The determination unit 12 compares the required torque Tn with the boundary torque Tx, and determines that the motor rotational speed N and the required torque Tn belong to the low torque region when the required torque Tn is equal to or less than the boundary torque Tx. When the required torque Tn exceeds the boundary torque Tx, the determination unit 12 compares the required torque Tn with the boundary torque Ty. When the required torque Tn is equal to or less than the boundary torque Ty, the determination unit 12 determines the motor rotational speed N and the required torque. It is determined that the torque Tn belongs to the middle torque region, and when the required torque Tn exceeds the boundary torque Ty, it is determined that the motor rotation speed N and the required torque Tn belong to the high torque region.

  The control unit 13 distributes the required torque Tn to the first and second motors 4a and 4b according to the region determined by the determination unit 12, and drives at least one of the first and second motors 4a and 4b. Specifically, when the region determined by the determination unit 12 is the low torque region, the control unit 13 distributes the requested torque Tn only to the first motor 4a, and the first motor 4a shares the shared torque Ta = Tn. Is output to the first inverter 3a from the battery 2 to supply the electric power necessary to output the electric power from the battery 2 to the first inverter 3a, and a control signal to interrupt the supply of electric power from the battery 2 to the second motor 4b is output. 2 Output to inverter 3b. In the case of the middle torque region, the control unit 13 acquires the maximum torque Tmax of the first motor 4a corresponding to the motor rotation number N with reference to the rotation speed-torque characteristic map stored in the storage unit 9, and acquires the maximum torque Tmax. The maximum torque Tmax is distributed to the first motor 4a, the torque Tn−Tmax that is insufficient with respect to the required torque Tn is calculated, and is distributed to the second motor 4b. The control unit 13 outputs a control signal for causing the first motor 4a to supply the first motor 4a with electric power necessary for the first motor 4a to output the shared torque Ta = Tmax, and the second motor 4b A control signal for supplying the second motor 4b with the electric power necessary for outputting the shared torque Tb = Tn−Tmax is output to the second inverter 3b. In the case of the high torque region, the control unit 13 calculates shared torques Ta and Tb that equally distribute the required torque Tn to the first and second motors 4a and 4b, and the first and second motors 4a and 4b A control signal for supplying electric power necessary for outputting the shared torque Ta = Tb = Tn / 2 from the battery 2 to the first and second motors 4a and 4b is output to the first and second inverters 3a and 3b. . Thereby, when the motor rotation speed N and the required torque Tn belong to the low torque region, only the first motor 4a is driven, and when it belongs to the middle torque region, the first motor 4a outputs the maximum torque Tmax. When the first and second motors 4a and 4b are driven and belong to the high torque region, the first and second motors 4a and 4b are driven equally and the required torque Tn is output.

  Next, motor control processing executed by the CPU 10 will be described with reference to FIG. FIG. 4 is a flowchart showing the motor control process. This process is repeatedly executed every predetermined time when the ignition key is in the ON state.

  When this processing is started, the accelerator opening detection sensor 6 detects the accelerator opening A, and the calculation unit 11 calculates a required torque Tn required for traveling of the vehicle based on the detected accelerator opening A. (Step S1).

  Next, the rotation speed detection sensor 7 detects the motor rotation speed N, and the determination unit 12 refers to the boundary torque map stored in the storage unit 9 and the motor rotation speed N detected by the rotation speed detection sensor 7. Boundary torques Tx and Ty corresponding to are determined (step S2).

  The determination unit 12 compares the required torque Tn with the boundary torques Tx and Ty to determine whether the motor rotation speed N and the required torque Tn belong to a low torque region, a middle torque region, or a high torque region. First, the determination unit 12 determines whether or not the required torque Tn is equal to or less than the boundary torque Tx (step S3).

  When the required torque Tn is equal to or less than the boundary torque Tx (step S3: YES), the determination unit 12 determines that the motor rotational speed N and the required torque Tn belong to the low torque region, and the control unit 13 determines the first motor 4a. Only drive (step S5). The control unit 13 distributes all of the required torque Tn to the first motor 4a, and the calculation unit 11 calculates electric power necessary for the first motor 4a to output the shared torque Ta = Tn. The control unit 13 outputs a control signal for supplying the power calculated by the calculation unit 11 from the battery 2 to the first motor 4a to the first inverter 3a, and interrupts the supply of power from the battery 2 to the second motor 4b. The control signal is output to the second inverter 3b. As a result, only the first motor 4a is driven and the required torque Tn is output.

  When the required torque Tn exceeds the boundary torque Tx (step S3: NO), the determination unit 12 determines whether the required torque Tn is equal to or less than the boundary torque Ty (step S4).

  When the required torque Tn is equal to or less than the boundary torque Ty (step S4: YES), the determination unit 12 determines that the motor rotation speed N and the required torque Tn belong to the middle torque region, and the control unit 13 determines the first motor 4a. The first and second motors 4a and 4b are driven in a state in which outputs the maximum torque Tmax (step S6). The control unit 13 refers to the rotation speed-torque characteristic map stored in the storage unit 9, acquires the maximum torque Tmax corresponding to the motor rotation speed N, and distributes the acquired maximum torque Tmax to the first motor 4a. The torque Tn−Tmax that is insufficient with respect to the required torque Tn is calculated and distributed to the second motor 4b. The control unit 13 outputs a control signal for causing the first motor 4a to supply the first motor 4a with electric power necessary for the first motor 4a to output the shared torque Ta = Tmax, and the second motor 4b A control signal for supplying the second motor 4b with the electric power necessary for outputting the shared torque Tb = Tn−Tmax is output to the second inverter 3b. Thus, the first and second motors 4a and 4b are driven in a state where the first motor 4a outputs the maximum torque, and the required torque Tn is output.

  When the required torque Tn exceeds the boundary torque Ty (step S4: NO), the determination unit 12 determines that the motor rotational speed N and the required torque Tn belong to the high torque region, and the control unit 13 determines the required torque Tn The control signals are output to the first and second inverters 3a and 3b by being equally distributed to the first and second motors 4a and 4b (step S7). As a result, the first and second motors 4a and 4b are driven equally and the required torque Tn is output.

  As described above, according to the motor control system 1 of the present embodiment, the driving of the first and second motors 4a and 4b is switched based on the overall motor efficiency, and therefore the first and second motors 4a and 4b are switched. It can be driven efficiently in the entire area.

  In the present embodiment, the first and second motors 4a and 4b are arranged in parallel, but may be arranged in series on one rotating shaft.

  In addition, when the first and second motors 4a and 4b are driven in the first and second driving states, the torque when the overall motor efficiency is reversed is set as the boundary torque Ty. Instead of the torque at the time of reverse rotation, a torque in the vicinity of the torque may be set as the boundary torque. In this case, for the motor control system that controls the driving of the two motors whose efficiency characteristics approximate to those of the first and second motors 4a and 4b, it is possible to execute the motor control process using the same boundary torque map. is there.

  The boundary torques Tx and Ty indicating the boundary of the region are set continuously corresponding to the continuously changing motor rotation speed N. For example, the boundary torques Tx and Ty corresponding to 0 to 300 rpm are The boundary torques Tx, Ty corresponding to Txa, Tya, 301 to 600 rpm are set stepwise so that the same boundary torques Tx, Ty correspond to the motor rotation speed N in a predetermined range, as in Txb, Tyb. May be. At this time, the overall motor efficiency improves as the predetermined range of the motor rotation speed N decreases, and decreases as it increases.

  Further, the maximum torque Tmax of the first motor 4a may be set stepwise so that the same maximum torque Tmax corresponds to the motor rotation speed N within a predetermined range, similarly to the boundary torques Tx and Ty.

  Next, a motor control system according to a second embodiment of the present invention will be described with reference to the drawings. In this embodiment, the two motors to be controlled have efficiency characteristics different from those of the first and second motors 4a and 4b, and the set regions (boundaries between the regions) are different. The configuration of the motor control system 1 of the present embodiment is the same as that of the first embodiment except that the two motors to be controlled are the third and fourth motors, and thus detailed description thereof is omitted. To do.

  The third and fourth motors have the same rated output, and the maximum torque Tmax2 is 400 N · m when the rotational speed is zero.

  The boundary torque map of the storage unit 9 stores boundary torques Tx2 and Ty2 indicating the boundaries of the first to third regions defined by the motor rotation speeds and output torques of the third and fourth motors. The rotation speed-torque characteristic map stores a maximum torque Tmax2 corresponding to an arbitrary motor rotation speed of the third and fourth motors. The torque distribution information stores a predetermined arithmetic expression for calculating the torque distribution of the third and fourth motors and the shared torque of the third and fourth motors in each region.

  Regions (boundaries between regions) set when the third and fourth motors are controlled will be described with reference to FIG. FIG. 5 is a diagram showing the overall motor efficiency of the third and fourth motors. A curve L3 in FIG. 5 indicates that the third and fourth motors are driven at 2000 rpm and only the third motor is driven in the torque region below the maximum torque Tmax2 of the third motor, and the third motor is driven in the torque region exceeding the maximum torque Tmax2 of the third motor. The overall motor efficiency in the third driving state in which the third and fourth motors are driven in a state where the motor outputs the maximum torque Tmax2, and the curve L4 indicates that the third and fourth motors are at 2000 rpm and the third motor is in the third driving state. The overall motor efficiency in the fourth driving state in which the third and fourth motors are equally driven in the entire torque region regardless of the maximum torque Tmax2 is shown.

  As shown in FIG. 5, the overall motor efficiency is higher in the third drive state (curve L3) in the torque region (first region) of the boundary torque Tx2 or less, and the torque region (boundary torque Tx2 to Ty2) ( In the second region, the fourth driving state (curve L4) is higher, and in the torque region (third region) exceeding the boundary torque Ty2, the third driving state (curve L3) is higher. Therefore, only the third motor is driven in the first region, the third and fourth motors are driven equally in the second region, and the third motor outputs the maximum torque in the third region. Driving the third and fourth motors increases the overall motor efficiency. Therefore, when the third and fourth motors are to be controlled, the boundary between the regions is the boundary torques Tx2 and Ty2, and the boundary torques Tx2 and Ty2 are stored in the boundary torque map.

  The determination unit 12 refers to the boundary torque map stored in the storage unit 9 and acquires boundary torques Tx2 and Ty2 corresponding to the motor rotation speed N, and the calculation unit 11 calculates the acquired boundary torques Tx2 and Ty2. The region is determined by comparing with the required torque Tn. The determination unit 12 compares the required torque Tn with the boundary torque Tx2, and determines that the motor rotational speed N and the required torque Tn belong to the first region when the required torque Tn is equal to or less than the boundary torque Tx2. When the required torque Tn exceeds the boundary torque Tx2, the determination unit 12 compares the required torque Tn with the boundary torque Ty2. When the required torque Tn is equal to or less than the boundary torque Ty2, the determination unit 12 determines the motor rotational speed N and the required torque. The torque Tn is determined to belong to the second region, and when the required torque Tn exceeds the boundary torque Ty2, the motor rotation speed N and the required torque Tn are determined to belong to the third region.

  When the region determined by the determination unit 12 is the first region, the control unit 13 distributes the required torque Tn only to the third motor, drives only the third motor, and when the region is the second region, The required torque Tn is evenly distributed to the third and fourth motors, and the third and fourth motors are driven equally. In the case of the third region, the control unit 13 distributes the maximum torque Tmax2 of the third motor to the third motor, and distributes the torque Tn−Tmax2 that is insufficient with respect to the required torque Tn to the fourth motor. The third and fourth motors are driven in a state where the third motor outputs the maximum torque Tmax2.

  As described above, according to the motor control system 1 of the present embodiment, the driving of the third and fourth motors can be switched based on the overall motor efficiency, so that the third and fourth motors are efficiently driven in the entire region. can do.

  Next, a motor control system according to a third embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a winding of a coil of a stator provided in the motor 4 is divided into two that can be connected, and the driving of the motor is controlled by blocking or connecting these two windings. In addition, the same code | symbol is attached | subjected to the structure similar to the said 1st Embodiment, and the detailed description is abbreviate | omitted.

  As shown in FIG. 6, the motor control system 1 of this embodiment includes a battery 2, an inverter 3, a motor 4, an accelerator opening sensor 6, a rotation speed detection sensor 7, and an ECU (Electric Control Unit) 8. With.

  The inverter 3 adjusts the power supplied from the battery 2 to the motor 4 in accordance with a control signal from the ECU 8. The motor 4 is divided so that the windings of the coils of the stator can be connected to the same number of first windings and second windings. The first winding and the second winding are interrupted or connected by the ECU 8. When the first winding and the second winding are interrupted, the power from the battery 2 is applied only to the first winding, and when the first winding and the second winding are connected. The electric power from the battery 2 is supplied to the first and second windings. The rotation speed detection sensor 7 detects the motor rotation speed N of the motor 4.

  In the boundary torque map of the storage unit 9, a boundary torque Tz indicating a boundary between the cutoff region and the connection region is set in advance and stored. The boundary torque Tz is the motor efficiency when the motor 4 is driven with the first and second windings cut off at an arbitrary motor speed, and the motor when the first and second windings are connected and driven. The motor efficiency is higher when the first and second windings are cut off and driven in the cut-off area, and the first and second windings are connected in the connection area. The motor efficiency when driving is higher.

  The second calculation unit of the calculation unit 11 calculates electric power necessary for the motor 4 to output the required torque Tn.

  The determination unit 12 determines whether the rotation speed N detected by the rotation speed detection sensor 7 and the required torque Tn calculated by the calculation unit 11 belong to the cutoff or connection region. Specifically, the determination unit 12 refers to the boundary torque map stored in the storage unit 9, determines the boundary torque Tz corresponding to the motor rotation speed N, and whether the required torque Tn is equal to or less than the boundary torque Tz. Determine whether or not. When the required torque Tn is equal to or less than the boundary torque Tz, the determination unit 12 determines that the motor rotational speed N and the required torque Tn belong to the cutoff region, and when the required torque Tn exceeds the boundary torque Tz, the motor rotational speed N And the required torque Tn are determined to belong to the connection region.

  The control unit 13 drives the motor 4 by blocking or connecting the first and second windings according to the region determined by the determination unit 12. Specifically, the control unit 13 shuts off the first and second windings when the motor rotation speed N and the required torque Tn belong to the shut-off area, and controls the first and second windings when they belong to the connection area. The second winding is connected, and a control signal for supplying electric power necessary for driving the motor 4 calculated by the calculation unit 11 from the battery 2 to the motor 4 is output to the inverter 3. As a result, when the motor rotation speed N and the required torque Tn belong to the cutoff region, the motor 4 is driven in a state where only the first winding is energized, outputs the required torque Tn, and belongs to the connection region. The motor 4 is driven in a state where the first and second windings are energized and outputs the required torque Tn.

  As described above, according to the motor control system 1 of the present embodiment, the motor 4 is driven with the first and second windings cut off or connected based on the motor efficiency of the motor 4. It can be driven efficiently in the region.

  In addition, the said embodiment is an example of this invention and can be changed in the range which does not deviate from this invention.

  The present invention is widely applicable to electric vehicles such as electric vehicles and hybrid vehicles.

1: Motor control system 2: Battery 3, 3a, 3b: Inverter 4, 4a, 4b: Motor 5: Power coupling part 6: Accelerator opening detection sensor 7: Revolution detection sensor 8: ECU (Electric Control Unit)
9: Storage unit (storage means)
10: CPU (Central Processing Unit)
11: Calculation unit 12: Determination unit (determination means)
13: Control unit (control means)
14: Propeller shaft 15: Differential gear 16a, 16b: Axle shaft 17a, 17b: Drive wheel

Claims (7)

A first motor and a second motor with the same rated output that output the required torque required for traveling of the vehicle to one drive shaft and the same motor rotation speed when driving the one drive shaft;
The plurality of regions defined by the motor rotation speed and the torque include a low torque region having a maximum torque corresponding to each motor rotation number of the first motor as a boundary on the high torque side, and a high torque in the low torque region. Storage means for storing a middle torque region adjacent to the side and a high torque region adjacent to the high torque side of the middle torque region;
When the motor rotation speed and the required torque when the vehicle travels belong to the low torque region, the first motor is driven so that all of the required torque is distributed, and when the motor belongs to the medium torque region The maximum torque of the first motor corresponding to the motor rotation number is distributed to the first motor, and the torque obtained by subtracting the maximum torque of the first motor from the required torque is distributed to the second motor. Control means for driving the first and second motors so that the first and second motors are driven and belong to the high torque range so that the required torque is evenly distributed. A motor control system characterized by The motor control system according to claim 1,
In the low torque region, when the first motor is driven so that the required torque is evenly distributed, the first motor is driven so that the required torque is all distributed. Motor efficiency is higher than
In the intermediate torque region, the maximum torque of the first motor corresponding to the motor speed is distributed to the first motor, and the torque obtained by subtracting the maximum torque of the first motor from the required torque is distributed to the second motor. When the first and second motors are driven, the motor efficiency is higher than when the first and second motors are driven so that the required torque is evenly distributed.
In the high torque region, when the first and second motors are driven so that the required torque is evenly distributed, the maximum torque of the first motor corresponding to the motor rotational speed is the first torque. The motor efficiency is higher than when driving the first and second motors so that a torque obtained by subtracting the maximum torque of the first motor from the required torque distributed to the motor is distributed to the second motor. Motor control system. A first motor and a second motor with the same rated output that output the required torque required for traveling of the vehicle to one drive shaft and the same motor rotation speed when driving the one drive shaft;
Storage means for storing a first region on the low torque side and a second region adjacent to the high torque side of the first region as a plurality of regions defined by the motor rotation speed and the torque,
When the motor rotation speed and the required torque when the vehicle travels belong to the first region, the first motor is driven so that the required torque is all distributed, and the motor belongs to the second region. Comprises a control means for driving the first and second motors so that the required torque is evenly distributed. The motor control system according to claim 3,
In the first region, when the first motor is driven so that the required torque is evenly distributed, the first motor is driven so that the required torque is all distributed. Motor efficiency is higher than
In the second region, when the first motor is driven so that the required torque is all distributed, the first motor and the second motor are driven so that the required torque is evenly distributed. Alternatively, the maximum torque of the first motor corresponding to the motor speed is distributed to the first motor, and the torque obtained by subtracting the maximum torque of the first motor from the required torque is distributed to the second motor. A motor control system characterized in that the motor efficiency is higher than when driving the first and second motors. The motor control system according to claim 3 or 4,
The plurality of areas stored in the storage means further includes a third area adjacent to the high torque side of the second area,
In the third region, the maximum torque of the first motor corresponding to the motor speed is distributed to the first motor, and the torque obtained by subtracting the maximum torque of the first motor from the required torque is distributed to the second motor. When the first and second motors are driven, the motor efficiency is higher than when the first and second motors are driven so that the required torque is evenly distributed.
The control means distributes the maximum torque of the first motor corresponding to the motor rotational speed to the first motor when the motor rotational speed and the required torque during vehicle traveling belong to the third region. And driving the first and second motors so that a torque obtained by subtracting the maximum torque of the first motor from the required torque is distributed to the second motor. A stator having the same number of first windings and second windings divided so as to be connectable is provided, and when the first and second windings are cut off, only the first winding is energized and driven, A motor for energizing and driving the first and second windings when the first and second windings are connected, and outputting a required torque required for running the vehicle;
Storage means for storing a low torque side cut-off area and a connection area adjacent to the high torque side of the cut-off area as a plurality of areas defined by the rotational speed and torque of the motor;
When the rotational speed of the motor and the required torque when the vehicle travels belong to the cut-off area, the first and second windings are cut off to drive the motor, and when the motor belongs to the connection area And a control means for driving the motor by connecting the first and second windings. The motor control system according to claim 6,
In the cut-off region, the motor efficiency is higher when the first and second windings are cut off and the motor is driven than when the first and second windings are connected and the motor is driven. ,
In the connection region, the motor efficiency is higher when driving the motor by connecting the first and second windings than when driving the motor by cutting the first and second windings. A motor control system characterized by that.

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