JP2016220463A - Control device for vehicle with permanent magnet type synchronous motor mounted therein, and method for setting upper limit temperature of permanent magnet type synchronous motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly accurately predict a current condition on which irreversible demagnetization may occur, and a demagnetization amount in a permanent magnet type synchronous motor.SOLUTION: A control device for a vehicle with the permanent magnet type synchronous motor mounted therein comprises: a control controller 100 which performs output torque control of the synchronous motor by controlling a d-axis current value and a q-axis current value to be applied to the synchronous motor; and a permanent magnet temperature estimation part 120 which estimates a temperature of a permanent magnet. The control controller 100 includes: a control region setting part 108 which is divided into a plurality of regions each defining the d-axis current value and the q-axis current value as parameters and to which an upper limit temperature for suppressing demagnetization of the permanent magnet is set for each region; a temperature comparison part 122 which compares the permanent magnet temperature that has been estimated by the permanent magnet temperature estimation part 120, with the upper limit temperature; and a deterioration discrimination part 124 which discriminates the synchronous motor is deteriorated if the permanent magnet temperature is higher than or equal to the upper limit temperature.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a vehicle control device equipped with a permanent magnet type synchronous motor and a method for setting an upper limit temperature of the permanent magnet type synchronous motor.

  In recent years, permanent magnet synchronous motors are used for driving wheels in electric motor vehicles (EV), hybrid electric motor vehicles (HEV), and the like. In a motor for a vehicle, the difference between increase and decrease in load during operation is larger than that of a stationary motor, and the temperature of the motor tends to increase. As a result, it is known that deterioration of the magnetic characteristics of the permanent magnet, that is, irreversible demagnetization, causes a reduction in motor torque and output (hereinafter referred to as motor deterioration).

  In the cited reference 1 below, the performance of the synchronous motor is brought to near the actual limit while preventing the occurrence of irreversible demagnetization (hereinafter also simply referred to as demagnetization) of the permanent magnet in the permanent magnet type synchronous motor. A control device is described which is capable.

JP 2014-131392 A

  However, although the technique described in the cited document 1 sets the upper limit value of the d-axis current according to the estimated value of the temperature (permanent magnet temperature) of the synchronous motor, the q-axis current is not considered at all. . For this reason, it is difficult to predict the current condition and amount of demagnetization in which irreversible demagnetization occurs with high accuracy. Therefore, it is difficult to suppress the deterioration of the permanent magnet type synchronous motor, and there is a possibility that the operable range is excessively limited.

  The present invention has been made in view of such a point, and the problem is that the permanent magnet of a permanent magnet type synchronous motor predicts the current condition and amount of demagnetization with high accuracy in a permanent magnet of a permanent magnet. To provide technology.

  In order to solve the above problems, the present invention sets an upper limit value of a current applied to the synchronous motor associated with the estimated temperature of the synchronous motor (permanent magnet) using the d-axis current value and the q-axis current value. It is characterized by that.

  Specifically, the present invention is directed to a vehicle control device equipped with a permanent magnet type synchronous motor and a method for setting an upper limit temperature of the permanent magnet type synchronous motor, and has taken the following solution.

  That is, the first invention is a permanent magnet type synchronous motor provided with a permanent magnet, and a control controller for controlling the output torque of the synchronous motor by controlling the d-axis current value and the q-axis current value applied to the synchronous motor. And a temperature control means for estimating the temperature of the permanent magnet, and intended for a vehicle control device equipped with a permanent magnet type synchronous motor, wherein the controller has a plurality of parameters using the d-axis current value and the q-axis current value as parameters. Comparing the upper limit temperature with the control area setting means that is divided into areas and set the upper limit temperature for suppressing the demagnetization of the permanent magnet for each of the previously divided areas, and the upper limit temperature estimated by the temperature estimation means And comparing means for determining that the synchronous motor is deteriorated when the permanent magnet temperature is higher than or equal to the upper limit temperature in the comparing means.

  According to this, since it is possible to determine the deterioration of the synchronous motor by setting the upper limit temperature in consideration of the q-axis current value in addition to the d-axis current value, the deterioration of the synchronous motor can be determined with high accuracy. can do.

  A second invention is a permanent magnet type synchronous motor provided with a permanent magnet, a controller for controlling the output torque of the synchronous motor by controlling a d-axis current value and a q-axis current value applied to the synchronous motor, and A controller for a vehicle equipped with a temperature estimating means for estimating the temperature of the permanent magnet and equipped with a permanent magnet type synchronous motor is a target, and the control controller sets a target output torque of the synchronous motor according to the running state of the vehicle. Target output torque setting means, target current value setting means for setting a target d-axis current value and a target q-axis current value to be applied to the synchronous motor according to a set value of the target output torque setting means, and a target d-axis current A control region setting unit that is partitioned into a plurality of regions using the value and the target q-axis current value as parameters, and an upper limit temperature is set for each of the previously partitioned regions to suppress demagnetization of the permanent magnet And a comparison means for comparing the permanent magnet temperature estimated by the temperature estimation means with the upper limit temperature, and a deterioration prediction for predicting the deterioration of the synchronous motor when the permanent magnet temperature is higher than or equal to the upper limit temperature in the comparison means. Means.

  According to this, since it is possible to predict the deterioration of the synchronous motor by setting the upper limit temperature in consideration of the q-axis current value in addition to the d-axis current value, the deterioration of the synchronous motor can be predicted with high accuracy. can do.

  According to a third aspect, in the second aspect, the target d-axis current value and the target q-axis current value set by the target current value setting means when the deterioration prediction means predicts that the synchronous motor is deteriorated. Are further provided with target current value changing means for changing the current value so that the synchronous motor does not deteriorate.

  According to this, when the deterioration of the synchronous motor is predicted, it is possible to suppress the deterioration of the motor by changing the target current value applied to the synchronous motor.

  A fourth invention is a permanent magnet type synchronous motor provided with a permanent magnet, a control controller for controlling the output torque of the synchronous motor by controlling a d-axis current value and a q-axis current value applied to the synchronous motor, A temperature estimation unit that estimates the temperature of the magnet and a cooling unit that cools the synchronous motor, and is intended for a vehicle control device equipped with a permanent magnet type synchronous motor. The controller is synchronized according to the running state of the vehicle. Target output torque setting means for setting the target output torque of the motor, and target current values for setting the target d-axis current value and the target q-axis current value to be applied to the synchronous motor according to the set values of the target output torque setting means The setting means and an upper limit for suppressing demagnetization of the permanent magnet, divided into a plurality of regions using the target d-axis current value and the target q-axis current value as parameters. When the control region setting means in which the degree is set, the comparison means for comparing the permanent magnet temperature estimated by the temperature estimation means with the upper limit temperature, and the comparison means, when the permanent magnet temperature is higher than or equal to the upper limit temperature, Cooling control means for controlling the cooling of the synchronous motor by the cooling means while maintaining the cooling of the synchronous motor by the cooling means when the permanent magnet temperature is lower than the upper limit temperature. It is what you have.

  According to this, when the permanent magnet temperature is higher than or equal to the upper limit temperature, the cooling control unit performs control so as to increase the cooling of the synchronous motor by the cooling unit, and therefore, according to the state of the permanent magnet temperature of the synchronous motor. Thus, it is possible to appropriately control the cooling means.

  According to a fifth aspect of the present invention, there is provided a permanent magnet type synchronous motor provided with a permanent magnet, a controller for controlling the output torque of the synchronous motor by controlling a d-axis current value and a q-axis current value applied to the synchronous motor, and A controller for a vehicle equipped with a temperature estimating means for estimating the temperature of the permanent magnet and equipped with a permanent magnet type synchronous motor is a target, and the control controller sets a target output torque of the synchronous motor according to the running state of the vehicle. Target output torque setting means, target current value setting means for setting a target d-axis current value and a target q-axis current value to be applied to the synchronous motor according to a set value of the target output torque setting means, and a target d-axis current A control region setting unit that is partitioned into a plurality of regions using the value and the target q-axis current value as parameters, and an upper limit temperature is set for each of the previously partitioned regions to suppress demagnetization of the permanent magnet And a comparison means for comparing the permanent magnet temperature estimated by the temperature estimation means with the upper limit temperature, and in the comparison means, if the permanent magnet temperature is higher than or equal to the upper limit temperature, it is set by the target current value setting means The target d-axis current value and the target q-axis current value include target current value changing means for changing the current value so that the synchronous motor does not deteriorate.

  According to this, since the target current value changing means changes the current value so that the synchronous motor does not deteriorate when the permanent magnet temperature is higher than or equal to the upper limit temperature, it is possible to suppress deterioration of the motor. It becomes.

  A sixth invention is directed to a method of setting an upper limit temperature of a permanent magnet type synchronous motor provided with a permanent magnet, and is a first method for actually measuring an output torque value of a synchronous motor with respect to a d-axis current value and a q-axis current value at room temperature. A second step of raising the temperature of the permanent magnet to a predetermined temperature, a third step of applying a predetermined d-axis current value and a q-axis current value to the synchronous motor at the predetermined temperature, and returning from the predetermined temperature to room temperature. Again, the fourth step of actually measuring the output torque value of the synchronous motor with respect to the d-axis current value and the q-axis current value at room temperature, the first output torque value actually measured in the first step, and the actually measured value in the fourth step. And a fifth step of setting a predetermined temperature to an upper limit temperature for a predetermined d-axis current value and a q-axis current value when the difference from the second output torque value is equal to or greater than a predetermined value. That.

  According to this, since the upper limit temperature of the permanent magnet is set in consideration of the q axis current value in addition to the d axis current value, the upper limit temperature of the permanent magnet can be set appropriately.

  According to a seventh aspect, in the sixth aspect, from the first step to the first step, changing at least one of the predetermined temperature in the second step, the predetermined d-axis current value and the q-axis current value in the third step. A sixth step of setting a control map indicating a control range of the d-axis current value and the q-axis current value with respect to the upper limit temperature by repeatedly performing up to five steps is further provided.

  According to this, it is possible to create a control map that takes into account the q-axis current value in addition to the d-axis current value.

  An eighth invention is directed to a vehicle control device equipped with a permanent magnet type synchronous motor that employs the method for setting an upper limit temperature described in the seventh invention, and an upper limit read from an estimated permanent magnet temperature and a control map. If the permanent magnet temperature is higher than or equal to the upper limit temperature, the cooling of the synchronous motor is enhanced, the command current value to the synchronous motor is changed, the deterioration of the synchronous motor is judged, and the deterioration is predicted. At least one of them is executed.

  According to this, according to the state of the permanent magnet temperature of the synchronous motor, it is possible to accurately control the cooling means, change the applied current to the synchronous motor, and determine and predict the deterioration of the synchronous motor with high accuracy. .

  ADVANTAGE OF THE INVENTION According to this invention, the current conditions and demagnetization amount which the irreversible demagnetization of the permanent magnet built in the permanent magnet type synchronous motor generate | occur | produces can be determined or estimated with high precision.

FIG. 1 is a schematic configuration diagram showing a vehicle control device equipped with a permanent magnet type synchronous motor according to a first embodiment of the present invention. FIG. 2 is a plurality of current-torque maps used in the method for setting the upper limit temperature of the permanent magnet type synchronous motor according to the first embodiment of the present invention. FIG. 3 is a graph showing the temperature dependence of the torque reduction rate and the upper limit temperature (demagnetization occurrence warning temperature) of the permanent magnet type synchronous motor. FIG. 4 shows a method for setting the upper limit temperature of the permanent magnet type synchronous motor according to the first embodiment of the present invention, which is divided according to the amplitude and phase of the current vector used for the current condition (combination of d-axis current and q-axis current). It is a graph for demonstrating the division | segmentation method to perform. FIG. 5 is a current-demagnetization occurrence warning temperature (upper limit temperature) map used in the method for setting the upper limit temperature of the permanent magnet type synchronous motor according to the first embodiment of the present invention. FIG. 6 is a demagnetization diagnosis flowchart of the permanent magnet in the permanent magnet type synchronous motor according to the first embodiment of the present invention. FIG. 7A is a schematic partial plan view showing an example of an arrangement shape of permanent magnets arranged in the rotor of the permanent magnet type synchronous motor according to the first embodiment of the present invention. FIG. 7B is a graph showing a relationship between a region where demagnetization of the permanent magnet occurs in the permanent magnet type synchronous motor shown in FIG. 7A and current values of the d-axis and the q-axis. FIG. 7C is a schematic partial plan view showing another example of the arrangement shape of the permanent magnets arranged in the rotor of the permanent magnet type synchronous motor according to the first embodiment of the present invention. FIG. 7D is a graph showing the relationship between the permanent magnet demagnetization region in the permanent magnet type synchronous motor shown in FIG. 7C and the d-axis and q-axis current values. FIG. 8 is a block diagram showing a control controller in a vehicle control apparatus equipped with a permanent magnet type synchronous motor according to the second embodiment of the present invention. FIG. 9 is a block diagram showing a control controller in a vehicle control apparatus equipped with a permanent magnet type synchronous motor according to a third embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its application, or its application.

(First embodiment)
FIG. 1 shows a vehicle control apparatus equipped with a permanent magnet type synchronous motor according to a first embodiment of the present invention. As shown in FIG. 1, a permanent magnet type synchronous motor (hereinafter also referred to as a synchronous motor) 200 drives an axle 230 via a speed reducer 210 and a differential mechanism 220. The synchronous motor 200 is provided with a cooling unit 240 that cools the synchronous motor 200 by, for example, a water cooling method when the temperature of the permanent magnet reaches or exceeds a predetermined temperature (demagnetization occurrence warning temperature (Tdemag) described later). It has been.

  The controller 100 detects motor torque from a torque sensor 301 provided in the synchronous motor 200. The controller 100 further includes a d-axis current detection unit 110 and a q-axis current detection unit 112, and detects a d-axis current and a q-axis current from a current sensor (not shown). The controller 100 also receives signals from a wheel speed sensor 302 that detects the rotational speed of the axle 230 and an accelerator sensor 303 that detects the accelerator opening.

  The controller 100 includes a permanent magnet temperature estimation unit 120, and estimates the magnet temperature of the synchronous motor 200 from the detected motor torque, d-axis current, and q-axis current. When the estimated temperature of the magnet temperature is equal to or higher than the above-described predetermined temperature, the controller 100 instructs the synchronous motor 200 to reduce at least one of the motor torque and the motor rotation speed, or the cooling unit. Instructions such as starting or increasing the flow rate of cooling water are given to 240. Note that the reduction of the motor torque or the like and the start of the cooling unit 240 may be performed simultaneously, or one of them may be performed.

(Permanent magnet demagnetization diagnosis method in permanent magnet type synchronous motor)
An example of a method for estimating the magnet temperature of the permanent magnet type synchronous motor 200 from the motor torque described above, the d-axis current, and the q-axis current will be described.

  It is well known that torque in a permanent magnet synchronous motor (PMSM) can be controlled by current (d-axis current, q-axis current).

  First, a map showing the relationship of “current” − “torque” − “magnet temperature” is acquired.

  Irreversible demagnetization in a permanent magnet occurs when the operating point on the magnetization curve is located below the knick (curved part) mainly due to heat and a reverse magnetic field (current). Therefore, if the three relationships of the magnet temperature, current, and operating point position become clear, the occurrence of demagnetization can be detected.

  In a permanent magnet type synchronous motor, since a permanent magnet is generally disposed in a rotor (rotor), it is difficult to detect the magnet temperature by a simple method. Therefore, in order to estimate the magnet temperature from the torque value of the motor torque, a map showing the relationship between current, torque and magnet temperature is created.

<Acquire current-torque relationship>
First, an example of an experimental method for creating a map showing a current-torque relationship among the three relationships of current-torque-magnet temperature will be described. The permanent magnet type synchronous motor used in the experiment is, for example, an IPM (Interior Permanent Magnet) motor in which a permanent magnet made of a Nd—Fe—B sintered alloy is embedded in a rotor.

  (1) A motor bench composed of a motor under test to be tested, a load motor constituting a load, and a torque meter is prepared, and a thermostatic chamber is installed so as to cover the motor under test.

  (2) The thermostat is operated with the motor under test stationary, and heat is applied to the magnet inside the motor under test. At this time, the magnet temperature is monitored by a thermocouple or the like, and this state is maintained until the magnet temperature reaches a predetermined temperature.

  (3) After the magnet temperature reaches a predetermined temperature, the thermocouple or the like is disconnected and the motor under test is driven under a predetermined current condition.

  (4) The torque of the motor under test at this time is measured, and a current-torque map is created.

  (5) The above (1) to (4) are repeated under the temperature conditions appropriately set in increments of, for example, 5 ° C. or 10 ° C. between -40 ° C. and 200 ° C., as shown in FIG. Create multiple current-torque maps.

<Obtain relationship between current and magnet demagnetization temperature>
Next, among the three relationships of current-torque-magnet temperature, a map showing the relationship of current-magnet temperature, more specifically, the relationship of current-magnet demagnetization occurrence temperature is created.

  By the way, when a permanent magnet type synchronous motor is driven with a load at an arbitrary current value, an irreversible decrease in torque occurs at a certain magnet temperature. That is, when the reference torque is measured with the load removed, the value of the reference torque is different. That is, as shown in FIG. 3, the motor torque decreases from the demagnetization occurrence temperature T0.

  Therefore, the demagnetization temperature T0 is experimentally obtained by the following procedure under each current condition.

  (1) Measure the reference torque of the motor under test at a reference temperature (room temperature (25 ° C.) or the like). The value of the reference torque here is arbitrary.

  (2) The magnet inside the rotor is heated until a predetermined temperature is reached. The heating method is the same as the method at the time of creating the map showing the current-torque relationship.

  (3) After the magnet temperature reaches a predetermined temperature, a predetermined current value is applied to drive the motor under test (thermal load driving).

  (4) The drive of the motor under test is stopped and cooled until the magnet temperature reaches the reference temperature, and then the torque value of the motor under test is measured again under the same conditions as in (1) above.

  (5) The torque value of the motor under test in (1) is compared with the torque value of the motor under test in (4).

  (6) As shown in FIG. 3, the above steps (1) to (5) are repeated until a torque change (decrease) occurs.

  (7) The temperature at which the torque change has occurred is defined as a demagnetization temperature T0, and the temperature at that time is recorded.

  (8) The above (1) to (7) are repeated by the number of current conditions (for the combination of d-axis current and q-axis current). Here, an example of a combination of a d-axis current and a q-axis current, which are current conditions, is shown. The first method is divided by the amplitude and phase of the current vector in FIG. For example, the amplitude is divided into 10 with respect to the maximum current amplitude, and the phase is divided into 10 degrees between the current phases 0 ° to 90 °. In the second method, for example, in FIG. 4, the d-axis current (id) and the q-axis current (iq) are both divided into 10 with respect to the dq-axis maximum current.

  As shown in FIG. 3, a “demagnetization occurrence warning temperature (Tdemag)” obtained by adding a temperature margin (ΔT) to the demagnetization occurrence temperature T0 obtained from the above experiment is calculated, and the current shown in FIG. -Obtain a map showing the relationship of the demagnetization occurrence warning temperature. Here, the temperature margin (ΔT) is arbitrary, but can be set to about 10 degrees to 30 degrees, for example.

  From the above, the demagnetization occurrence warning temperature (Tdemag) which is the upper limit temperature of the permanent magnet type synchronous motor is set.

(Permanent magnet demagnetization diagnosis flow for permanent magnet type synchronous motor)
Next, a diagnosis flow of demagnetization diagnosis in a permanent magnet type synchronous motor mounted on a vehicle and operating (driving) will be described with reference to FIG.

  First, in step ST1, the torque of the synchronous motor 200 is detected by the torque sensor 301, and the d-axis current and the q-axis current of the synchronous motor 200 are detected by the current sensor. As a modified example, only the d-axis current and the q-axis current may be detected without detecting the torque of the synchronous motor 200.

  Next, in step ST2, the current magnet temperature T1 is calculated from the torque value, d-axis current value, and q-axis current value detected in step ST1, using a plurality of current-torque maps created in advance shown in FIG. Is estimated.

    Next, in step ST3, using the current-demagnetization occurrence warning temperature map shown in FIG. 5, the demagnetization occurrence warning temperature Tdemag in the operating state (current state) is obtained and compared with the estimated magnet temperature T1.

  Next, in step ST4, when the estimated magnet temperature T1 is higher than or equal to the demagnetization occurrence warning temperature Tdemag, in the next step ST5, the controller 100 demagnetizes the permanent magnets constituting the synchronous motor 200. Outputs a command to avoid the occurrence of As described above, the command to be output is, for example, a command for reducing at least one of the motor torque and the motor rotation speed for the synchronous motor 200. In this case, the current value may be reduced by reducing at least one of the d-axis current value and the q-axis current value. For example, when the factor of the demagnetizing field (reverse magnetic field) to the permanent magnet is the d-axis current, Only the d-axis current value may be reduced. The further command is a command for starting the cooling unit 240 or increasing the flow rate of the cooling water. The cooling unit 240 may be used simultaneously with the reduction of the current value or may be used alone.

(Relationship between rotor structure and demagnetization current conditions in synchronous motor)
As a result of various studies, the inventors of the present application have found that, for example, the current conditions for generating demagnetization differ depending on the arrangement of the permanent magnets in the rotor of the IPM motor.

  For example, as shown in FIG. 7A, a rotor (rotor) 202 is disposed inside a stator (stator) 201 of the synchronous motor 200, and a plurality of permanent magnets 203 are arranged on the periphery of the rotor 202 with respect to the periphery. 7B, the demagnetizing field factor is mainly the d-axis current as shown in FIG. 7B. At this time, the magnet temperature is constant. On the other hand, as shown in FIG. 7C, when a plurality of permanent magnets 203 arranged at the peripheral portion of the rotor 202 of the synchronous motor 200 are arranged in a line with respect to the peripheral portion, as shown in FIG. 7D. In addition, it can be seen that the demagnetizing field is caused by the q-axis current in addition to the d-axis current. Again, the magnet temperature is constant. Therefore, with the demagnetization prediction method that considers only the value of the d-axis current as in the prior art described above, it is difficult to accurately predict the current condition and the amount of demagnetization in which demagnetization occurs.

-Effect-
As described above, according to the present embodiment, paying attention to the deterioration of the magnetic characteristics of the permanent magnet also affected by the q-axis current value, the permanent magnet in the region set by the d-axis current value and the q-axis current value. If the permanent magnet temperature is higher than or equal to the demagnetization occurrence warning temperature Tdemag by comparing the upper limit temperature for suppressing demagnetization, that is, the demagnetization occurrence warning temperature Tdemag and the actual permanent magnet temperature, the permanent magnet Since the applied current value and the cooling unit are controlled so as to avoid the occurrence of demagnetization, demagnetization of the permanent magnet can be suppressed.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to FIG. FIG. 8 shows a block configuration of functional blocks showing a control controller that constitutes a control device for a vehicle equipped with a permanent magnet type synchronous motor according to the second embodiment.

  As shown in FIG. 8, the controller 100 according to the second embodiment includes an output torque control unit 106, a control region setting unit 108, a d-axis current detection unit 110, a q-axis current detection unit 112, and a permanent. A magnet temperature estimation unit 120, a temperature comparison unit 122, and a deterioration determination unit 124 are provided.

  The output torque control unit 106 controls the output torque of the synchronous motor 200 by controlling the d-axis current value and the q-axis current value applied to the synchronous motor 200.

  The control region setting unit 108 receives the d-axis current and the q-axis current detected by the current sensor via the d-axis current detection unit 110 and the q-axis current detection unit 112, respectively. Further, the control area setting unit 108 is divided into a plurality of areas (current-demagnetization occurrence warning temperature map shown in FIG. 5) using the d-axis current value and the q-axis current value as parameters for each of these areas. A demagnetization occurrence warning temperature Tdemag which is an upper limit temperature for suppressing demagnetization of the permanent magnet incorporated in the synchronous motor 200 is set.

  The permanent magnet temperature estimation unit 120 estimates the permanent magnet temperature T1 in the operating synchronous motor 200 from the d-axis current value and the q-axis current value and a plurality of current-torque maps created in advance shown in FIG. To do.

  The temperature comparison unit 122 compares the permanent magnet temperature T1 estimated by the permanent magnet temperature estimation unit 120 with the upper limit temperature.

  The deterioration determination unit 124 determines that there is a high possibility of deterioration of the synchronous motor 200 when the permanent magnet temperature T1 is higher than or equal to the upper limit temperature in the temperature comparison unit 122. As described with reference to FIG. 3, the demagnetization occurrence warning temperature Tdemag, which is the upper limit temperature, is provided with a temperature margin (ΔT) with respect to the demagnetization occurrence temperature T0. Does not lead to immediate degradation.

-Effect-
Thus, according to the second embodiment, based on the map (FIG. 5) created based on the d-axis current value and the q-axis current value detected from the synchronous motor 200, the upper limit temperature Tdemag and the operating motor In comparison with the permanent magnet temperature T1, the deterioration of the synchronous motor 200 can be determined with high accuracy (Third Embodiment).
Hereinafter, a third embodiment of the present invention will be described with reference to FIG. FIG. 9 shows a block configuration of functional blocks showing a control controller constituting a control device for a vehicle equipped with a permanent magnet type synchronous motor according to the third embodiment.

  As illustrated in FIG. 9, the controller 100 according to the third embodiment sets a target output torque of the synchronous motor 200 according to the traveling state of the vehicle with respect to the controller 100 according to the second embodiment. A target output torque setting unit 130; and a target current value setting unit 132 that sets a target d-axis current value and a target q-axis current value to be applied to the synchronous motor 200 in accordance with a set value of the target output torque setting unit 130; When the temperature comparison unit 122 determines that the permanent magnet temperature T1 is higher than or equal to the upper limit temperature, the deterioration prediction unit 126 that predicts demagnetization of the permanent magnet in the synchronous motor 200, and the deterioration prediction unit 126 causes the synchronous motor 200 to When it is predicted that deterioration will occur, the target d-axis current value and the target q-axis current value set by the target current value setting unit 132 are used as the synchronous motor 200. Further includes a target current value changing section 134 for changing the current value so as not to deteriorate. As a modification, the target current value changing unit 134 does not depend on the signal from the deterioration predicting unit 126, but the current value applied to the synchronous motor 200 based on the signal value representing the temperature comparison result from the temperature comparing unit 122. It is good also as composition which changes directly.

  In addition to the deterioration prediction unit 126, a cooling control unit 128 may be added. The cooling control unit 128 controls the cooling unit 240 (FIG. 1) to increase the cooling of the synchronous motor 200 when the permanent magnet temperature T1 is higher than or equal to the upper limit temperature in the temperature comparison unit 122. Also good. In addition, when the permanent magnet temperature T1 is lower than the upper limit temperature, the cooling of the synchronous motor 200 by the cooling unit 240 may be maintained or weakened.

-Effect-
As described above, according to the third embodiment, when the deterioration predicting unit 126 predicts deterioration of the permanent magnet incorporated in the synchronous motor 200, the synchronous motor 200 is changed to the synchronous motor 200 via the target current value changing unit 134. Reduction of the applied current value can be commanded. Further, when the cooling control unit 128 is provided, it is possible to quickly suppress demagnetization of the permanent magnet by issuing a command for increasing the cooling effect to the cooling unit 240 (FIG. 1).

  In the above-described embodiment, the demagnetization occurrence warning temperature Tdemag obtained by giving a temperature margin to the demagnetization occurrence temperature T0 as the upper limit temperature is used. However, the demagnetization occurrence temperature T0 may be set as the upper limit temperature. In this case, a map indicating the relationship between the current and the demagnetization temperature is created, and permanent magnet demagnetization is determined and predicted.

  The main body of the controller 100 can be configured by combining a general-purpose microprocessor (MPU), a general-purpose memory device, an input / output (I / O) device, and the like.

  In the above embodiment, the electric motor vehicle (EV) shown in FIG. 1 is shown as a vehicle equipped with a permanent magnet type synchronous motor. However, the present invention is not limited to this, and the vehicle is equipped with an internal combustion engine (engine). It may be a hybrid electric vehicle (HEV). In this case, a series type hybrid that uses the engine only as a generator may be used, or a parallel type hybrid that uses the engine also for driving wheels.

  The control device for a vehicle equipped with the permanent magnet type synchronous motor according to the present invention and the method for setting the upper limit temperature of the permanent magnet type synchronous motor are applied to applications where it is necessary to accurately predict irreversible demagnetization in the permanent magnet. can do.

100 control controller 106 output torque control unit 108 control region setting unit (control region setting means)
110 d-axis current detection unit 112 q-axis current detection unit 120 permanent magnet temperature estimation unit (temperature estimation means)
122 Temperature comparison part (comparison means)
124 Degradation determination unit (determination means)
126 Deterioration prediction unit (deterioration prediction means)
128 Cooling control unit (cooling control means)
130 Target output torque setting unit (target output torque setting means)
132 Target current value setting unit (target current value setting means)
134 Target current value changing unit (target current value changing means)
200 Permanent magnet synchronous motor (synchronous motor)
240 Cooling unit 301 Accelerator sensor

Claims (8)

A permanent magnet type synchronous motor provided with a permanent magnet, a controller for controlling the output torque of the synchronous motor by controlling the d-axis current value and the q-axis current value applied to the synchronous motor, and the temperature of the permanent magnet A vehicle control device comprising a temperature estimating means for estimating, and equipped with the permanent magnet type synchronous motor,
The controller is
A control region setting that is partitioned into a plurality of regions using the d-axis current value and the q-axis current value as parameters, and an upper limit temperature for suppressing demagnetization of the permanent magnet is set for each of the previously partitioned regions. Means,
A comparison means for comparing the permanent magnet temperature estimated by the temperature estimation means with the upper limit temperature;
A control device for a vehicle equipped with a permanent magnet type synchronous motor, comprising: determining means for determining that the synchronous motor is deteriorated when the temperature of the permanent magnet is higher than or equal to the upper limit temperature in the comparing means. A permanent magnet type synchronous motor provided with a permanent magnet, a controller for controlling the output torque of the synchronous motor by controlling the d-axis current value and the q-axis current value applied to the synchronous motor, and the temperature of the permanent magnet A vehicle control device comprising a temperature estimating means for estimating, and equipped with the permanent magnet type synchronous motor,
The controller is
A target output torque setting means for setting a target output torque of the synchronous motor according to a traveling state of the vehicle;
Target current value setting means for setting a target d-axis current value and a target q-axis current value to be applied to the synchronous motor according to a set value of the target output torque setting means;
A control region that is partitioned into a plurality of regions using the target d-axis current value and the target q-axis current value as parameters, and an upper limit temperature for suppressing demagnetization of the permanent magnet is set for each of the previously partitioned regions Setting means;
A comparison means for comparing the permanent magnet temperature estimated by the temperature estimation means with the upper limit temperature;
A controller for a vehicle equipped with a permanent magnet type synchronous motor, comprising: a deterioration predicting means for predicting deterioration of the synchronous motor when the permanent magnet temperature is higher than or equal to the upper limit temperature in the comparing means. In a vehicle control device equipped with the permanent magnet type synchronous motor according to claim 2,
When the deterioration prediction unit predicts that the synchronous motor is deteriorated, the synchronous motor does not deteriorate the target d-axis current value and the target q-axis current value set by the target current value setting unit. A vehicle control apparatus equipped with a permanent magnet type synchronous motor, further comprising target current value changing means for changing the current value as described above. A permanent magnet type synchronous motor provided with a permanent magnet, a control controller for controlling the output torque of the synchronous motor by controlling the d-axis current value and the q-axis current value applied to the synchronous motor, and estimating the temperature of the permanent magnet And a temperature control means for cooling, a cooling means for cooling the synchronous motor, and a vehicle control device equipped with the permanent magnet type synchronous motor,
The controller is
A target output torque setting means for setting a target output torque of the synchronous motor according to a traveling state of the vehicle;
Target current value setting means for setting a target d-axis current value and a target q-axis current value to be applied to the synchronous motor according to a set value of the target output torque setting means;
A control region that is partitioned into a plurality of regions using the target d-axis current value and the target q-axis current value as parameters, and an upper limit temperature for suppressing demagnetization of the permanent magnet is set for each of the previously partitioned regions Setting means;
A comparison means for comparing the permanent magnet temperature estimated by the temperature estimation means with the upper limit temperature;
In the comparison means, when the permanent magnet temperature is higher than or equal to the upper limit temperature, the cooling means controls to increase the cooling of the synchronous motor, while the permanent magnet temperature is lower than the upper limit temperature. And a cooling control means for controlling so as to maintain or weaken the cooling of the synchronous motor by the cooling means, and a control apparatus for a vehicle equipped with a permanent magnet type synchronous motor. A permanent magnet type synchronous motor provided with a permanent magnet, a controller for controlling the output torque of the synchronous motor by controlling the d-axis current value and the q-axis current value applied to the synchronous motor, and the temperature of the permanent magnet A vehicle control device comprising a temperature estimating means for estimating, and equipped with the permanent magnet type synchronous motor,
The controller is
A target output torque setting means for setting a target output torque of the synchronous motor according to a traveling state of the vehicle;
Target current value setting means for setting a target d-axis current value and a target q-axis current value to be applied to the synchronous motor according to a set value of the target output torque setting means;
A control region that is partitioned into a plurality of regions using the target d-axis current value and the target q-axis current value as parameters, and an upper limit temperature for suppressing demagnetization of the permanent magnet is set for each of the previously partitioned regions Setting means;
A comparison means for comparing the permanent magnet temperature estimated by the temperature estimation means with the upper limit temperature;
In the comparison means, when the permanent magnet temperature is higher than or equal to the upper limit temperature, the synchronous motor uses the target d-axis current value and the target q-axis current value set by the target current value setting means. A vehicle control device equipped with a permanent magnet type synchronous motor having target current value changing means for changing a current value so as not to deteriorate. A method for setting an upper limit temperature of a permanent magnet type synchronous motor provided with a permanent magnet,
A first step of actually measuring an output torque value of the synchronous motor with respect to a d-axis current value and a q-axis current value at room temperature;
A second step of raising the temperature of the permanent magnet to a predetermined temperature;
A third step of applying a predetermined d-axis current value and a q-axis current value to the synchronous motor, respectively, at the predetermined temperature;
A fourth step of measuring the output torque value of the synchronous motor with respect to the d-axis current value and the q-axis current value at normal temperature again from the predetermined temperature to room temperature;
If the difference between the first output torque value actually measured in the first step and the second output torque value actually measured in the fourth step is equal to or greater than a predetermined value, the predetermined temperature is set to the predetermined d-axis current. And a fifth step of setting the upper limit temperature for the q-axis current value and a permanent magnet type synchronous upper limit temperature setting method in which a permanent magnet is provided on the rotor. It is a setting method of the upper limit temperature of the permanent magnet type synchronous motor according to claim 6,
Repeating from the first step to the fifth step while changing at least one of the predetermined temperature in the second step and the predetermined d-axis current value and q-axis current value in the third step. The method of setting the upper limit temperature of the permanent magnet type synchronous motor further comprising: a sixth step of setting a control map indicating a control range of the d-axis current value and the q-axis current value with respect to the upper limit temperature. A control device for a vehicle equipped with a permanent magnet type synchronous motor adopting the upper limit temperature setting method according to claim 7,
Comparing the estimated permanent magnet temperature with the upper limit temperature read from the control map;
If the permanent magnet temperature is higher than or equal to the upper limit temperature, the cooling of the synchronous motor is enhanced, the command current value to the synchronous motor is changed, and the deterioration of the synchronous motor is determined and the deterioration is predicted. A control device for a vehicle equipped with a permanent magnet type synchronous motor that executes at least one.

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