JP6611892B1 - Electric braking device - Google Patents

Abstract

An electric braking device that suppresses a reduction in braking force even when an abnormality occurs in a control system of a three-phase winding of a motor. Wheel brakes 4 are provided on the left and right wheels. The wheel brakes 4 include a motor 7 having a set of three-phase windings 11 and 12 and first and second inverters 21 that drive the motor 7. , 22 and a control device 40 that controls the control device 40. When an abnormality occurs in the control system of any one of the three-phase windings 11 (or 12), the control device 40 By controlling the operation of the inverters 21 and 22, the supply current to the three-phase winding 11 (or 12) where the abnormality has occurred is set to zero, and the supply current to the other three-phase winding 12 (or 11) is preset. The increased upper limit current value is set as the upper limit, and the current is increased from the state before the occurrence of the abnormality. [Selection] Figure 4

Description

  The present application relates to an electric braking device that obtains a braking force of a vehicle by driving an electric motor.

  As an alternative to the conventionally used hydraulic braking device, development of an electric braking device that obtains a braking force of a vehicle by driving an electric motor is in progress. The braking device has an important function of the vehicle, and a system that can safely stop even if a failure occurs is essential.

  For example, in Patent Document 1 below, when the braking force generation function of one wheel fails, the required braking force is distributed to the remaining wheel braking devices, the yaw moment of the vehicle is suppressed, and the maximum braking force is ensured. A brake control system is disclosed.

Japanese Patent No. 4474393

  However, in order not to impair the vehicle balance during braking, it is necessary to acquire various sensor values (yaw rate, steering angle, lateral acceleration, etc.), or to calculate braking force distribution to the remaining brakes based on it, and to determine yaw moment is required.

  Also, when the braking force of each brake is increased to ensure the required braking force, the supply current to the motor is increased. However, if the supply current is increased more than usual, the winding of the motor coil There is a risk of deterioration of the durability of the winding due to the rise in temperature of the coil, and demagnetization of the permanent magnet due to an increase in the magnetic field acting in the direction of demagnetizing the permanent magnet of the rotor.

  The present application discloses a technique for solving the above-described problems, and an object thereof is to provide an electric braking device for a vehicle that can be stopped more safely even when a failure occurs.

The electric braking device disclosed in the present application is provided with wheels on the left and right of the front side and the rear side of the vehicle, and wheel brakes are individually provided on the left and right wheels of at least one of the front side and the rear side, The wheel brake includes a motor including a rotor having a permanent magnet and a stator having a set of three-phase windings independent from each other, and has a brake mechanism that is driven by the motor to brake the wheel, and A first power converter connected to the three-phase winding on one side of the set of three-phase windings to control the motor, and the motor connected to the three-phase winding on the other side A second power converter that controls the power, and a control device that controls both the first power converter and the second power converter,
The control device includes one of the three-phase windings of a set of the three-phase windings constituting the wheel brake corresponding to a wheel on one side of the wheel brakes disposed on the left and right wheels. When an abnormality occurs in the control system of the line, the first power converter and the second power converter are controlled to reduce the supply current to the three-phase winding on the abnormality occurrence side to zero. In addition, the supply current to the other three-phase winding without occurrence of abnormality is increased from the state before the occurrence of abnormality with an increase upper limit current value set in advance as an upper limit , and the other wheel without occurrence of abnormality Each of the supply currents for the set of three-phase windings of the wheel brake corresponding to is increased or decreased from the state before the occurrence of abnormality with the preset increase upper limit current value as an upper limit .

According to the electric braking device disclosed in the present application, even when a failure occurs in a component related to the electric braking device of the vehicle, the braking force generated by the brake mechanism on one side of the wheel is applied to the brake mechanism on the other side of the wheel. The braking force generated at the same time as that of the left and right wheels can be kept balanced, and secondary failures can be suppressed, so that the vehicle can be stopped more safely.

It is a block diagram which shows the example of mounting to the vehicle the electric braking device which concerns on Embodiment 1 of this application. It is a block diagram which shows the other mounting example to the vehicle of the electric braking device which concerns on Embodiment 1 of this application. It is a block diagram which shows an example of the connection relationship between the wheel brake which comprises the electric brake device which concerns on Embodiment 1 of this application, a brake mechanism, and a battery. It is a block diagram which shows an example of the electric circuit of the wheel brake which comprises the electric braking device which concerns on Embodiment 1 of this application. It is a functional block diagram which shows the control apparatus of the wheel brake which comprises the electric brake device which concerns on Embodiment 1 of this application. It is a block diagram which shows the further example of mounting to the vehicle the electric braking device which concerns on Embodiment 1 of this application. It is a characteristic view which shows distribution of the braking force in the case of the structure of FIG. It is a schematic sectional drawing which shows the whole structure of the motor which concerns on Embodiment 1 of this application. It is a fragmentary sectional view of the motor shown in FIG.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram showing an example of mounting an electric braking device according to Embodiment 1 of the present application on a vehicle.

  In the first embodiment, the vehicle 1 includes four wheels 2a to 2d, front, rear, left and right, and left and right wheels 2a, 2b on the front side of the vehicle 1 are provided with brake mechanisms 3a, 3b, respectively. The wheel brakes 4a and 4b are individually connected to the brake mechanisms 3a and 3b, respectively, and a DC power source (here, an in-vehicle battery) 5 is commonly connected to the wheel brakes 4a and 4b. And the electric brake device of this application is comprised by the combination of the said wheel brake device 4a, 4b, brake mechanism 3a, 3b, and DC power supply 5. FIG.

  In the first embodiment, as shown in FIG. 1, it is assumed that the left and right wheels 2a and 2b on the front side of the vehicle 1 are provided with brake mechanisms 3a and 3b and wheel brakes 4a and 4b, respectively. However, the present invention is not limited to this, and as shown in FIG. 2, it is also possible to employ a configuration in which brake mechanisms 3c and 3d and wheel brakes 4c and 4d are provided on the left and right wheels 2c and 2d on the rear side of the vehicle 1, respectively. is there. Further, here, reference numeral 2 is used when generically referring to the wheels 2a to 2d, reference numeral 3 is used when generically referring to the brake mechanisms 3a to 3d, and reference numeral 4 is used when generically referring to the wheel brakers 4a to 4d. .

  As shown in FIGS. 3 and 4, each wheel brake 4 includes a motor 7 that drives the brake mechanism 3 of the wheel 2, a first three-phase winding 11 and a second 3 included in the stator 8 of the motor 7. A first inverter 21 and a second inverter 22 as power converters that supply AC power to the phase winding 12 respectively, and a control device 40 that controls the first inverter 21 and the second inverter 22 are provided. .

  When the driver operates the brake, the control device 40 calculates the necessary pressing force for obtaining the required braking force according to the brake operation amount, outputs the necessary torque to the motor 7, and presses the friction material. By controlling the current supplied to the motor 7 so that the necessary pressing force is output, the friction material of the brake mechanism 3 moves and the friction material is pressed against the non-friction material to control the vehicle 1. It is configured to obtain power.

  The motor 7 constituting each wheel brake 4 includes a rotor having a permanent magnet and a stator 8 having a set of three-phase windings 11 and 12 which are independent from each other. The first inverter 21 converts the DC power supplied from the DC power source 5 into AC power and supplies the AC power to the first three-phase winding 11. Similarly, the second inverter 22 converts the DC power supplied from the DC power supply 5 into AC power and supplies it to the second three-phase winding 12.

  Both the first inverter 21 and the second inverter 22 have the same configuration, and are connected to the positive side switching elements (upper arms) 311 and 312 connected to the positive terminal of the DC power source 5 and the negative terminal of the DC power source 5. Three series of serial circuits in which switching elements (lower arms) 321 and 322 on the negative electrode side to be connected are connected in series corresponding to each phase U, V, and W are provided. That is, each of the first inverter 21 and the second inverter 22 includes a total of six switching elements for power conversion.

  The connection nodes that are the connection points between the positive-side switching elements 311 and 312 and the negative-side switching elements 321 and 322 of the respective phases correspond to the first three-phase winding 11 and the second 3 of the corresponding phase, respectively. The phase winding 12 is connected to connection terminals TU1, TV1, TW1 and TU2, TV2, TW2. The series circuit of each phase is provided with shunt resistors 331 and 332 for current detection, respectively. The potential difference between both ends of the shunt resistors 331 and 332 is input to the control device 40.

  As shown in FIG. 4, the control device 40 includes an arithmetic processing device (computer) 41 such as a CPU (Central Processing Unit), a storage device 42 that exchanges data with the arithmetic processing device 41, and external signals to the arithmetic processing device 41. , The first drive circuit 51 for turning on / off the switching elements 311 and 321 of the first inverter 21 according to the control signal output from the arithmetic processing unit 41, and the second A second drive circuit 52 that drives the switching elements 321 and 322 of the inverter 22 on and off is provided.

  As the storage device 42, a RAM (Random Access Memory) configured to be able to read and write data from the arithmetic processing device 41, and a ROM (Read Only Memory) configured to be able to read data from the arithmetic processing device 41. Etc. are provided. The input circuit 43 includes an A / D converter that inputs output signals from various sensors or switches to the arithmetic processing unit 41.

  The input circuit 43 is inputted with the value of the potential difference between both ends of the shunt resistors 331 and 332, the stroke sensor 81 as a brake operation amount, the rotation sensor 82 for detecting the rotation angle of the rotor constituting the motor 7, and the direct current. A voltage sensor 83 that detects the power supply voltage of the power supply 5, a vehicle speed sensor 84 that detects the traveling speed of the vehicle 1, a load sensor 85 that detects the pressing force of the friction material of the brake mechanism 3, and the like are connected.

FIG. 5 is a functional block diagram of the wheel brake controller.
The control device 40 includes a first motor current control unit 61 that controls a current supplied to the first three-phase winding 11, and a first inverter according to a current command from the first motor current control unit 61. The first driving circuit 51 that outputs a driving signal for driving on and off the switching elements 311 and 321 of the 21 and a second motor current control unit 62 that controls the current supplied to the second three-phase winding 12; The second drive circuit 52 outputs a drive signal for driving on and off the switching elements 312 and 322 of the second inverter 22 in response to a current command from the second motor current control unit 62.

  Further, the control device 40 detects a first abnormality detection unit 71 that detects whether or not an abnormality has occurred in the control system of the first three-phase winding 11 and the second three-phase winding 12 from sensor information such as a current detection value. And a second abnormality detection unit 72. That is, the first abnormality detection unit 71 and the second abnormality detection unit 72 detect, for example, currents that flow when the switching elements 311, 321, 312, and 322 are turned on / off by the shunt resistors 331 and 332, and the currents By determining whether or not the value is normal, it is determined whether or not an abnormality has occurred in the control system of the first three-phase winding 11 and the second three-phase winding 12. Instead of the shunt resistors 331 and 332, a non-contact current sensor can be adopted.

  The functions of the first motor current control unit 61 and the second motor current control unit 62, and the first abnormality detection unit 71 and the second abnormality detection unit 72 shown in FIG. The arithmetic processing device 41 provided executes the software (program) stored in the storage device 42 such as a ROM, and in addition to the storage device 42, the input circuit 43, the first drive circuit 51, the second drive circuit 52, etc. It is realized by cooperating with the hardware.

Next, the braking control operation in the electric braking apparatus having the above-described configuration will be described.
(A) When the first three-phase winding 11 and the second three-phase winding 12 of the left and right wheel brakes 4a, 4b are all operating normally When the driver operates the brake, the operation is performed from the stroke sensor 81. A brake signal corresponding to the amount is sent to the control device 40. The control device 40 includes a load sensor 85 that detects the pressing force of the friction material of the brake mechanisms 3a and 3b, a vehicle speed sensor 84 that detects the traveling speed of the vehicle 1, and the like so as to generate the required braking force according to the amount of brake operation. Based on this information, the required pressing force for obtaining the required braking force is calculated, the necessary torque is output to the motor 7, and the friction material pressing mechanism outputs the required pressing force. The supply current to the three-phase winding 11 and the second three-phase winding 12 is controlled.

  That is, here, as an example, in the configuration shown in FIG. 1, when attention is paid to the left wheel brake 4a of the left and right wheel brakes 4a and 4b of the vehicle 1, the arithmetic processing unit 41 detects the stroke sensor of the wheel brake 4a. Based on information such as the amount of brake operation from 81, the pressing force detected by the load sensor 85, and the vehicle speed from the vehicle speed sensor 84, torque required for the motor 7 to output the required pressing force (hereinafter referred to as required torque). ) Is calculated, and a shared torque obtained by multiplying the required torque by the share ratio of supply current to the first three-phase winding 11 and the second three-phase winding 12 (normally 50%) is obtained. Then, the first motor current control unit 61 and the second motor current control unit 62 determine supply currents to the first three-phase winding 11 and the second three-phase winding 12 based on this shared torque. Calculate the current command. The first drive circuit 51 and the second drive circuit 52 perform current feedback control using a vector control method in accordance with each current command from the first motor current control unit 61 and the second motor current control unit 62. The switching elements 311, 321, 312, and 322 of the first inverter 21 and the second inverter 22 are on / off controlled by PWM control.

  The supply current supplied to the first three-phase winding 11 and the supply current supplied to the second three-phase winding 12 are configured to have a phase difference of 30 electrical angles. Therefore, the fifth and seventh harmonics of the magnetomotive force of the permanent magnet provided in the rotor, the fifth and seventh harmonics of the magnetomotive force of the stator 8 and the fifth and seventh harmonics of the drive current are generated. The sixth-order torque ripple is offset by the first three-phase winding 11 and the second three-phase winding 12 and reduced.

  Although the above description has focused on the left wheel brake 4a of the left and right wheel brakes 4a, 4b of the vehicle 1, the brake control operation has been described, but the brake control operation of the right wheel brake 4b is also described. It is the same.

(B) When abnormality occurs in the control system of either the first three-phase winding 11 or the second three-phase winding 12 of the left and right wheel brakes 4a, 4b. Here, it is easy to understand the contents of the present application. Therefore, as an example, in the left wheel brake 4a of the left and right wheel brakes 4a and 4b, an abnormality occurs in the control system of the first three-phase winding 11, and the first abnormality detector 71 detects the abnormality. Is detected.

  When the first abnormality detection unit 71 detects the occurrence of an abnormality in the control system, the first motor current control unit 61 corresponding to the first abnormality detection unit 71 that has detected the abnormality detects the first motor current control unit 61 accordingly. The current supplied to the three-phase winding 11 is made zero. That is, when the first abnormality detection unit 71 detects an abnormality, the first motor current control unit 61 opens the switching elements 311 and 321 of all the upper and lower arms of the first inverter 21 corresponding thereto. .

  On the other hand, since no abnormality has occurred in the control system of the second three-phase winding 12, the second abnormality detector 72 does not detect any abnormality. Therefore, the second motor current control unit 62 on the side where no abnormality is detected (hereinafter referred to as the normal side) sets the current supplied to the normal-side second three-phase winding 12 to a preset increase upper limit. With the current value Ish as the upper limit, it is increased from the state before the occurrence of the abnormality.

  Here, the increase upper limit current value Ish is appropriately set depending on the design of the vehicle 1 on which the vehicle braking device 4 is mounted. For example, when the same required torque as that before the occurrence of the abnormality is required even when the abnormality occurs, the increase upper limit current value Ish is set to twice the maximum supply current value of the state before the occurrence of the abnormality. That is, when the share ratio of the supply current to the first three-phase winding 11 and the second three-phase winding 12 is 50% when normal, the supply of the first three-phase winding 11 when an abnormality occurs The current sharing ratio is 0%, the supply current sharing ratio of the second three-phase winding 12 on the normal side is 100%, and the supply current to the second three-phase winding 12 is 2 in the state before the occurrence of abnormality. Doubled.

Further, when a required torque of a level that causes no problem in practice when an abnormality occurs (for example, 70% of normal) is required, the increase upper limit current value Ish for the state before the occurrence of the abnormality is 1. Set to 4 times. That is, when the share ratio of the supply current to the first three-phase winding 11 and the second three-phase winding 12 is 50% when normal, the supply of the first three-phase winding 11 when an abnormality occurs The current sharing ratio is 0%, the supply current sharing ratio of the normal second three-phase winding 12 is 70%, and the supply current to the second three-phase winding 12 is 1 in the state before the occurrence of abnormality. .4 times.
In the first embodiment, it is assumed that the increase upper limit current value Ish is set to at least 1.2 times the value of the supply current in the state before the occurrence of the abnormality.

  As described above, when an abnormality occurs, the arithmetic processing unit 41 uses a preset share ratio (when the abnormality occurs) to the required torque of the motor 7 calculated based on the brake operation amount, the pressing force, and the vehicle speed. In this example, the normal shared torque multiplied by 100% or 70%) is calculated. Then, the normal second motor current control unit 62 calculates a current command for the second three-phase winding 12 based on this shared torque. The second drive circuit 52 turns on and off the switching elements 321 and 322 of the second inverter 22 by current feedback control and PWM control using a vector control method in response to a current command from the second motor current control unit 62. Control. Thus, in the first embodiment, the second motor current control unit 62 on the normal side executes the maximum torque current control even when an abnormality occurs.

  As described above, when an abnormality occurs in the control system of the first three-phase winding 11 of the left wheel brake 4a, the motor 7 is obtained by reducing the supply current to the first three-phase winding 11 to zero. Can be compensated for by increasing the current supplied to the normal-side second three-phase winding 12 from the state before the occurrence of the abnormality. Thereby, the fall of the braking force generated with the brake mechanism 3a can be suppressed, and the vehicle 1 can be safely stopped even when an abnormality occurs.

  At this time, an increase in the supply current to the normal-side second three-phase winding 12 is limited by a preset increase upper limit current value Ish, so that the second three-phase winding 12 due to the current increase is increased. The increase in the amount of heat generated or the influence on the demagnetization of the permanent magnet can be managed in a pre-estimated range, and the cooling performance of the motor 7 is designed in advance within the assumed range, and the coercive force of the permanent magnet is adjusted. Since it can be designed in advance, the occurrence of a secondary failure can be suppressed, and a safer stopping operation of the vehicle 1 can be realized.

  Here, the case where an abnormality has occurred in the control system of one first three-phase winding 11 of the left wheel brake 4a has been described, but the other second three-phase winding of the same left wheel brake 4a. Even when an abnormality occurs in the control system of the line 12, the operation of the braking control is the same.

  In the case where an abnormality occurs in the control system of one of the first three-phase winding 11 and the second three-phase winding 12 of the wheel brake 4a, focusing on the left wheel brake 4a. Although the braking control has been described, under such a state that an abnormality has occurred in the control system of either the first three-phase winding 11 or the second three-phase winding 12 of the left wheel brake 4a. Next, the braking control in the right wheel brake 4b where no abnormality has occurred will be described.

  The first three-phase winding 11 and the second three-phase winding 11 of the wheel brake 4b on the normal side (right side here) in which no abnormality has occurred so as to match the torque output from the wheel brake 4a on the abnormality occurrence side (here left side). By increasing or decreasing the supply current of the three-phase winding 12, the braking force generated by the right brake mechanism 3 b becomes the same as the braking force generated by the left brake mechanism 3 a and is applied to the left and right wheels 2 a and 2 b. The balance of braking force can be maintained.

  For example, in the left wheel brake 4a, when, for example, 70% of the normal level is required as the required torque at a level that causes no problem in practice when an abnormality occurs, the first motor current of the right (normal) wheel brake 4b The controller 61 and the second motor current controller 62 calculate the shared torque by multiplying the required torque by 35%, which is half of the required torque. Then, a current command for determining a supply current to the first three-phase winding 11 and the second three-phase winding 12 is calculated based on this shared torque. As a result, the output torques of the left wheel brake 4a and the right wheel brake 4b are the same. As a result, the braking force to the left and right wheels 2a, 2b is the same, and the left / right balance of the vehicle 1 during braking can be maintained. it can.

  Alternatively, in the left wheel brake 4a, when, for example, 70% of the normal level is required as a required torque at a level that causes no problem in practice when an abnormality occurs, the first motor current of the right (normal) wheel brake 4b One of the control unit 61 and the second motor current control unit 62 is multiplied by 70% of the required torque to calculate the shared torque to obtain a current command for the supply current, and the other sets the shared torque to 0. % To make the current command value of the supply current zero. Even in this case, the output torques of the left wheel brake 4a and the right wheel brake 4b are the same, and as a result, the braking force to the left and right wheels 2a, 2b is the same, and the left / right balance of the vehicle 1 during braking is balanced. Can keep.

  In addition to this, when an abnormality occurs in the control system of the left wheel brake 4a, the left wheel brake 4a operates in a single three phase, whereas the normal right wheel brake 4b uses a double three phase. The difference in continued operation can be reduced. That is, when an abnormality occurs in the left wheel brake 4a, electric power is supplied to only one side of the first three-phase winding 11 and the second three-phase winding 12, and the motor 7 is driven. Accordingly, the normal right wheel brake 4b is also in a state in which the motor 7 is driven by supplying power to only one side of the first three-phase winding 11 and the second three-phase winding 12 in the same manner. As a result, the difference in the presence or absence of ripples with respect to the pressing force on the brake mechanisms 3a and 3b by the left and right wheel brakes 4a and 4b is eliminated. For this reason, the braking force of the vehicle 1 is obtained in a state where the left and right balance is maintained. Also, driver feeling is improved.

  Further, in the first motor current control unit 61 and the second motor current control unit 62 of the normal right wheel brake 4b, the side for controlling the supply current so as to be 70% shared torque, and 0% shared It is also possible to perform control to alternately switch the side that controls the supply current in a time-sharing manner so as to obtain torque. In this way, the burden on the first inverter 21 and the second inverter 22 for supplying power to the first three-phase winding 11 and the second three-phase winding 12 is distributed. Deterioration can be suppressed.

  In the above description, a case where an abnormality has occurred in the control system of the first three-phase winding 11 and the second three-phase winding 12 of the left wheel brake 4a of the left and right wheel brakes 4a, 4b. Although the premise of the braking control operation has been described, the present invention is not limited to this, and the control system of any of the first three-phase winding 11 and the second three-phase winding 12 of the wheel brake 4b on the right side of the vehicle 1 is used. It goes without saying that the operation of the braking control is exactly the same when an abnormality occurs.

  Further, in the present application, when the left and right wheels 2a and 2b on the front side as shown in FIG. 1 are provided with wheel brakes 4a and 4b, respectively, or the left and right wheels 2c and 2d on the rear side as shown in FIG. As shown in FIG. 6, the wheel brakes 4a to 4d are attached to all the front left and right wheels 2a and 2b and the rear left and right wheels 2c and 2d. It is also possible to adopt the provided configuration.

  In the case of the vehicle 1 having such a configuration, the braking force applied to the front wheels 2 a and 2 b on the front side of the vehicle 1 and the braking force applied to the rear wheels 2 c and 2 d include a braking force distribution determined from the load distribution of the vehicle 1. That is, for example, as shown by the solid curve in FIG. 7, the front wheels 2a, 2b on the front side and the wheels 2c, 2d on the rear side have a distribution ratio of the braking force. In addition, the frictional force between the road surface and the tire cannot be fully utilized, or the wheel locks quickly.

  Therefore, for example, when an abnormality occurs in any one of the wheel brakes 4a and 4b provided on the left and right wheels 2a and 2b on the front side as described above, or on the wheels provided on the left and right wheels 2c and 2d on the rear side. When an abnormality occurs in the control system in one of the brakers 4c and 4d and the output torque is reduced compared to the normal time, the front side where no abnormality has occurred in accordance with the braking force distribution shown by the solid line in FIG. By reducing the output to the wheel brakes 4a and 4b or the rear wheel brakes 4c and 4d, it is possible to ensure the balance of the braking forces of the front and rear wheels 2a, 2b and 2c, 2d of the vehicle 1.

  As described above, an abnormality occurs in one of the control systems of the three-phase winding, and the influence when the supply current to other normal three-phase windings is increased in accordance with this abnormality is shown in FIGS. Next, with reference to FIG. 8 is a schematic cross-sectional view showing the overall structure of the motor according to Embodiment 1 of the present application, and FIG. 9 is a partial cross-sectional view of the motor shown in FIG.

  When the supply current of the three-phase winding on the normal side is increased, the ampere turn value (current × number of turns) is increased, and the magnetic field acting in the direction of demagnetizing the permanent magnet 10 of the rotor 9 is increased. When the ampere turn value is increased, the permanent magnet 10 is demagnetized in a normal design, and the performance of the motor 7 is deteriorated. Furthermore, if the supply current of the normal three-phase winding is increased, the amount of heat generation also increases. With normal design, the drive duration time until the temperature of the three-phase winding reaches the allowable temperature is shortened, and the brake operation is limited. Is done.

  In order to avoid this, the increase upper limit current value Ish is set to the rated current value of the three-phase winding. That is, even if the supply current of the three-phase winding is increased to the increased upper limit current value Ish, the demagnetization factor of the permanent magnet 10 can be maintained below the allowable demagnetization factor, and the temperature of the three-phase winding is continuously maintained below the allowable temperature. So that the increase upper limit current value Ish is set to the rated current value of the three-phase winding in advance.

  Here, the allowable demagnetization factor is a practically acceptable demagnetization factor, and is set to an arbitrary value (for example, 3%) of 5% or less, for example. The demagnetization factor is an irreversible demagnetization factor, and is, for example, a reduction rate of the interlinkage magnetic flux of the permanent magnet 10 based on the normal time.

The increase upper limit current value Ish is set to the rated current value of the three-phase winding as described above, but is preferably set to satisfy any one of the following relationships (1) to (3). .
(1) The increase upper limit current value Ish is such that the demagnetization factor of the permanent magnet 10 is less than or equal to a predetermined allowable demagnetization factor at the maximum operating temperature of the motor 7, and the temperature of the three-phase winding is predetermined. It is set in advance to the maximum value in the range of the supply current that falls below the allowable temperature. Here, the maximum operating temperature is the maximum environmental temperature of the motor that is allowed in the specification.

  Here, the allowable temperature is determined to be the maximum winding temperature at which the insulation of the coating of the three-phase winding can be secured with a sufficient margin in the assumed usage period of the vehicle 1. Further, it is required that the temperature of the three-phase winding is continuously lower than the allowable temperature.

(2) When there is a margin in the demagnetization factor, the increase upper limit current value Ish is the maximum value of the supply current range in which the temperature of the three-phase winding is equal to or lower than a predetermined allowable temperature at the maximum operating temperature of the motor 7 Set to. When the temperature of the three-phase winding has a margin, the increase upper limit current value Ish is a supply current at which the demagnetization factor of the permanent magnet 10 is less than or equal to a predetermined allowable demagnetization factor at the maximum operating temperature of the motor 7. Set to the maximum value in the range.

(3) The increase upper limit current value Ish is set based on the ampere turn value (current × number of turns). That is, the increase upper limit current value Ish is set as the increase upper limit ampere turn value, and the arithmetic processing unit 41 sets the supply ampere turn value to the normal three-phase winding as the upper limit increase ampere turn value, It is comprised so that it may increase rather than the normal time. When the ampere turn value is used for management, the demagnetization factor of the permanent magnet 10 can be easily managed.

  By the way, the maximum torque at the time of occurrence of an abnormality is specified by the design specifications of the basic performance of the vehicle 1, and the sharing ratio at the time of occurrence of the abnormality and the increased upper limit current value Ish may be determined from the maximum torque at the time of occurrence of the abnormality. In this case, it is necessary to design the cooling mechanism for the permanent magnet 10 and the three-phase winding so as to achieve the specified increase upper limit current value Ish.

  The permanent magnet 10 is set (designed) based on a condition in which the supply current to the normal three-phase winding is increased to the increased upper limit current value Ish. Specifically, the coercive force of the permanent magnet 10 has a predetermined demagnetizing factor when the supply current to the normal three-phase winding is increased to the increased upper limit current value Ish at the maximum operating temperature of the motor 7. It is set (designed) to be less than or equal to the allowable demagnetization factor. Further, the operating point permeance of the permanent magnet 10 has a predetermined demagnetizing factor when the supply current to the normal three-phase winding is increased to the increased upper limit current value Ish at the maximum operating temperature of the motor 7. It is set to be less than the allowable demagnetization factor. The coercive force of the permanent magnet 10 can be increased by changing the material, coating, etc. of the permanent magnet 10. The operating point permeance of the permanent magnet 10 can be set to a desired value by changing the circumferential width W of the permanent magnet 10, the thickness t of the permanent magnet 10, and the air gap L, as shown in FIG. .

  When the supply current to the normal three-phase winding is increased to the increased upper limit current value Ish at the maximum operating temperature of the motor 7, the three-phase winding cooling mechanism It is set (designed) to be below the specified allowable temperature. For example, the heat sink for heat dissipation, the heat transfer mechanism from the winding to the heat sink for heat dissipation, and the like are changed in design. Further, the allowable temperature may be increased by improving the heat resistance of the coating of the three-phase winding. Further, a cooling mechanism for the switching element is designed according to the increase upper limit current value Ish.

  Therefore, even when an abnormality occurs in one set, by increasing the supply current to the three-phase winding on the normal side, the performance of the motor close to normal is ensured, and the permanent magnet 10 of the rotor 9 is demagnetized. It is possible to prevent the basic performance of the motor 7 from being lowered and to prevent the drive duration time from being shortened due to the heat generated by the three-phase winding of the motor 7. For this reason, it can be set as a wheel brake with improved safety and reliability.

  Regarding the motor 7 of the first embodiment, the combination of the number of poles and the number of slots is not particularly limited. Further, instead of a brushless motor with a three-phase delta connection, a star-connection brushless motor or a two-pole two-pair brushed motor may be used. The winding specifications of the first three-phase winding 11 and the second three-phase winding 12 may be either distributed winding or concentrated winding.

  In addition, although an exemplary configuration is described in the present application, various features, aspects, and functions described in this embodiment are not limited to application of the specific embodiment. Or various combinations are applicable.

  Accordingly, innumerable modifications not illustrated are envisaged within the scope of the technology disclosed in the present application. For example, a case where at least one component is deformed, a case where it is added, a case where it is omitted, and a case where at least one component is extracted and used are included.

1 car, 2, 2a-2d wheels, 3, 3a-3d brake mechanism,
4, 4a to 4d Wheel brake, 5 DC power supply, 7 Motor, 8 Stator, 9 Rotor, 10 Permanent magnet, 11 First three-phase winding, 12 Second three-phase winding,
21 first inverter, 22 second inverter,
311, 321, 312, 322 switching element, 331, 332 shunt resistor, 40 control device, 41 arithmetic processing device, 42 storage device, 43 input circuit,
51 1st drive circuit, 52 2nd drive circuit, 61 1st motor current control part,
62 2nd motor current control part, 71 1st abnormality detection part, 72 2nd abnormality detection part.

Claims (14)

Wheels are provided on the left and right sides of the front side and the rear side of the vehicle, and at least one of the left and right wheels on the front side and the rear side is individually provided with a wheel brake, and the wheel brake includes a rotor having a permanent magnet. And a motor composed of a stator having a set of three-phase windings independent from each other, a brake mechanism that is driven by the motor to brake the wheels, and includes a set of the three-phase windings. A first power converter that is connected to the three-phase winding on one side and controls the motor, and a second power converter that is connected to the three-phase winding on the other side and controls the motor; A control device for controlling both the first power converter and the second power converter;
The control device includes one of the three-phase windings of a set of the three-phase windings constituting the wheel brake corresponding to a wheel on one side of the wheel brakes disposed on the left and right wheels. When an abnormality occurs in the control system of the line, the first power converter and the second power converter are controlled to reduce the supply current to the three-phase winding on the abnormality occurrence side to zero. In addition, the supply current to the other three-phase winding without occurrence of abnormality is increased from the state before the occurrence of abnormality with an increase upper limit current value set in advance as an upper limit , and the other wheel without occurrence of abnormality Wherein each of the supply currents for the one set of the three-phase windings of the wheel brake corresponding to is increased or decreased from the state before the occurrence of the abnormality with the preset increase upper limit current value as an upper limit. Braking device. 2. The electric braking according to claim 1 , wherein the control device controls each supply current to one set of the three-phase windings of the other wheel brake that has no abnormality to be the same. apparatus. The control device sets the supply current of one of the three-phase windings to zero and the supply current of the other three-phase winding to one set of the three-phase windings of the other wheel brake that has no abnormality. 2. The electric braking apparatus according to claim 1 , wherein the electric braking device is increased from a state before the occurrence of abnormality with the preset upper limit current value as an upper limit. The control device includes: the three-phase winding that sets the supply current to zero with respect to one set of the three-phase windings of the other wheel brake that does not generate an abnormality; and the increased upper limit current that is set in advance. The electric braking device according to claim 3 , wherein the three-phase winding that is increased from the state before the occurrence of abnormality is alternately switched in a time-sharing manner with the value as an upper limit. The wheel brake is provided on each of the left and right wheels on the front side and the rear side, and the control device has an abnormality in a control system of any one of the three-phase windings constituting the wheel brake. If the output torque of one of the front and rear wheel brakes is lower than before the occurrence of an abnormality, the braking force of the other wheel brake is set according to the braking force distribution before and after the vehicle. The electric braking device according to any one of claims 1 to 4 , wherein the electric braking device is lowered. The electric braking apparatus according to any one of claims 1 to 5, wherein the increase upper limit current value is set to a rated current value of the three-phase winding. The increase upper limit current value is preset to a maximum value in a range of a supply current in which the demagnetization factor of the permanent magnet is equal to or less than a predetermined allowable demagnetization factor at the maximum operating temperature of the motor. The electric braking device according to any one of claims 1 to 6 . The increase upper limit current value is set in advance to a maximum value in a range of supply current in which the temperature of each of the three-phase windings of each set is equal to or lower than a predetermined allowable temperature at the maximum operating temperature of the motor. The electric braking apparatus according to any one of claims 1 to 6 , wherein: The increase upper limit current value is such that, at the maximum operating temperature of the motor, the demagnetization factor of the permanent magnet is equal to or less than a predetermined allowable demagnetization factor, and the temperature of the three-phase winding is equal to or less than a predetermined allowable temperature. The electric braking device according to any one of claims 1 to 6 , wherein the electric braking device is preset to a maximum value in a range of the supplied current. 10. The electric braking apparatus according to claim 1, wherein the increase upper limit current value is set based on an ampere turn value obtained by multiplying the current by the number of turns of the winding. . The permanent magnet may be any of claims 1 to 10, characterized in that it is set based on conditions in the case where the current supplied to the three-phase windings is increased to the increased upper limit current value 1 The electric braking device according to item. Coercivity of the permanent magnet, the maximum use temperature of the motor, the current supplied to the 3-phase windings when increased to the increased upper limit current value, below the allowable demagnetization of demagnetization factor is predetermined electric braking device as claimed in any one of claims 11, characterized in that set. The operating point permeance of the permanent magnet is such that the demagnetization factor is less than or equal to a predetermined allowable demagnetization factor when the supply current to the three-phase winding is increased to the increased upper limit current value at the maximum operating temperature of the motor. electric braking apparatus according to any one of claims 12 to be set from claim 1, characterized in. The cooling mechanism that cools the three-phase winding increases the temperature of the three-phase winding when the supply current to the three-phase winding is increased to the increased upper limit current value at the maximum operating temperature of the motor. The electric braking device according to any one of claims 1 to 13 , wherein the electric braking device is set to be equal to or lower than a predetermined allowable temperature.

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