JP2004187339A - Controller for motor to be mounted on car and motor system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the demagnetization of a permanent magnet arranged in a rotor at a low temperature. <P>SOLUTION: A current limiter 40 estimates and calculates the temperature of the permanent magnet of a motor generator 2, based on the temperature Tm detected by a temperature detector 39. In case that the temperature Tp falls under a set temperature and the demagnetization possibly occurs, it reduces command currents Ids and Iqs at a rate equivalent to or over the reduction rate of the magnitude of the coercive force Hcj by the drop of temperature of the permanent magnet. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention uses a vehicle-mounted motor control device that controls a vehicle-mounted motor having a permanent magnet in a power generation mode in which a rotating force is obtained from the outside to rotate or a powering mode in which the motor itself generates and rotates. The present invention relates to a motor system for a vehicle.
[0002]
[Prior art]
Patent Document 1 discloses a technology for preventing low-temperature demagnetization of a permanent magnet type brushless motor used in an automobile.
[0003]
[Patent Document 1]
JP 2001-136771 A
[0004]
[Problems to be solved by the invention]
For example, a hybrid vehicle receives efficient motor assist when the engine speed is low and sufficient torque cannot be output. When the vehicle decelerates, the motor operates as a generator to collect energy, and when the vehicle temporarily stops at an intersection or the like, the engine is stopped to save fuel (idling stop). Even when the engine is stopped, auxiliary machines such as an air conditioner are driven by the motor.
[0005]
A motor used as an assisting / generating motor (motor generator) or a starter generator of such a hybrid vehicle needs to generate a large torque at the time of starting the vehicle or at a low speed. In addition, since such an in-vehicle motor is rotated by the engine, it is necessary to suppress the induced voltage of the motor, particularly when the motor is rotated at high speed. As means for suppressing the induced voltage, a magnetic flux amount of a permanent magnet provided on the rotor is reduced, a field weakening control, or the like is used.
[0006]
Taking an example of a motor using ferrite as the material of the permanent magnet, the ferrite has magnetic properties that decrease the coercive force with a decrease in temperature, so that the permanent magnet may be demagnetized in a low temperature environment. There is. In particular, the temperature environment of the vehicle is severe, and in the above-described vehicle-mounted motor, demagnetization is more likely to occur due to a large current flowing to obtain a high torque at the time of starting or at a low speed.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control device for a vehicle-mounted motor in which permanent magnets provided in a rotor are less likely to be demagnetized, and a vehicle motor system using the same. It is in.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the control device for a vehicle-mounted motor according to claim 1 controls the vehicle-mounted motor in a power generation mode in which the motor is rotated by obtaining a rotational force from the outside or a power running mode in which the motor itself generates and rotates. In a control device for a vehicle-mounted motor to be controlled, a temperature sensor attached to the vehicle-mounted motor, temperature detection means for detecting a temperature of a permanent magnet based on an output signal of the temperature sensor, When the temperature is lower than the set temperature, current limiting means is provided for reducing the current flowing through the coil at a rate equal to or greater than the rate of reduction in the magnitude of the coercive force due to the temperature drop of the permanent magnet. .
[0009]
According to this configuration, when there is a possibility that the temperature of the permanent magnet falls below the set temperature and demagnetization occurs, the coil is reduced to the same or greater than the previously obtained reduction rate of the coercive force due to the temperature drop of the permanent magnet. Since the reverse magnetic field acting on the permanent magnet is reduced by reducing the upper limit value of the conduction current, the demagnetization can be reliably prevented even when the temperature of the permanent magnet is low. In particular, in-vehicle motors that are driven in the power generation mode and the powering mode are energized with a large current to output a large torque at, for example, start-up or low speed, but the above-described current limitation ensures occurrence of demagnetization. Can be prevented. Here, the coercive force of the permanent magnet is considered as the coercive force HcJ of the JH curve indicating the magnetization of the material.
[0010]
According to a second aspect of the present invention, there is provided a vehicle motor control device comprising: a temperature sensor attached to the vehicle motor; a temperature detecting means for detecting a temperature of the permanent magnet based on an output signal of the temperature sensor; Power conversion means for inputting a voltage from the coil and outputting an AC voltage to the coil, switching means connected between the external power supply and the power conversion means, a resistor connected in parallel with the switching means, and a permanent magnet. Open / close control means for controlling the open / close means to be in an open state on condition that the detected temperature is lower than a predetermined set temperature.
[0011]
According to this configuration, when the detected temperature of the permanent magnet is lower than the set temperature, the current flowing from the external power supply to the power conversion unit flows through the resistor, and is input to the power conversion unit by a voltage drop of the resistor. Voltage decreases. As a result, the AC voltage that can be output by the power conversion means decreases, the current flowing through the coil of the vehicle motor is suppressed, and the low-temperature demagnetization of the permanent magnet can be prevented. On the other hand, when the detected temperature of the permanent magnet is equal to or higher than the set temperature, the opening / closing means is closed, so that no voltage loss occurs in the resistor.
[0012]
Further, the control device for a vehicle-mounted motor according to claim 3 reduces the current flowing through the coil to a predetermined current value from when the vehicle-mounted motor is started until a predetermined delay time elapses. It is characterized by comprising current limiting means.
[0013]
According to this configuration, the coil current is reduced during the period from the start of the on-vehicle motor, which is often cooled to a low temperature, to the elapse of a predetermined delay time, so that a temperature sensor is separately provided. Therefore, low temperature demagnetization of the permanent magnet can be prevented.
[0014]
In this case, the opening / closing means connected between the external power supply and the power conversion means may be kept open until the delay time elapses, and the opening / closing means may be switched to the closed state on condition that the delay time has passed ( Claim 4). In addition, by mounting the resistor on the vehicle motor, the temperature of the vehicle motor and thus the permanent magnet motor can be increased by the heat generated by the resistor, so that it is possible to quickly escape from a state where low-temperature demagnetization is easy. 5).
[0015]
The vehicle motor system according to the sixth aspect includes the vehicle-mounted motor used as a power source of the vehicle (for example, a hybrid vehicle) and the above-described control device, and thus the vehicle is used in winter or in a cold region. Even in this case, it is possible to prevent a decrease in driving force due to demagnetization.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
Hereinafter, a first embodiment in which the present invention is applied to a vehicle motor system of a hybrid vehicle will be described with reference to FIGS.
FIG. 2 shows a schematic configuration of a drive system of the hybrid vehicle. The shafts of the engine 1, the motor generator 2 (corresponding to an in-vehicle motor), the compressor motor 3 of an air conditioner, and other auxiliary machines are connected by power connecting means 5 using a belt 4. A clutch 6 is provided between the shaft of the engine 1 and the power coupling means 5 for coupling and releasing the mechanical coupling. A transmission 7 is arranged on a power output side of the engine 1, and wheels 11 are connected to an output side of the transmission 7 via a drive shaft 8, a differential gear 9, and an axle 10. A starter 12 for starting the engine 1 is provided separately.
[0017]
The vehicle is equipped with various control units for controlling the engine 1, the motor generator 2, the clutch 6, the transmission 7, and the like. The control unit 13 is a device for controlling the motor generator 2, and includes an inverter 14 connected to the motor generator 2, a DC-DC converter 15 connected to a DC terminal of the inverter 14, and a DC-DC converter 15 connected to the inverter 14. It comprises an ECU (electronic control unit) 16 for controlling the DC converter 15 and the like.
[0018]
The vehicle is equipped with a battery 17 having a voltage of 36V and a battery 18 having a voltage of 12V. The battery 17 is connected to the DC terminal of the inverter 14, and the battery 18 is connected to the output terminal of the DC-DC converter 15. The starter 12 operates by receiving a voltage supply from a battery 18, and the ECU 16 includes a power supply circuit that converts the voltage of the battery 18 into a control power supply voltage (for example, 5V). The control line 19 connects the ECU 16 with the inverter 14 and the DC-DC converter 15.
[0019]
The control unit 13 operates the motor generator 2 as a motor when the vehicle starts to assist the engine 1 (powering mode), and operates the generator as needed during normal driving to charge the batteries 17 and 18 (power generation mode). ). When the vehicle is temporarily stopped at an intersection or the like, the control unit 13 drives auxiliary equipment such as the compressor motor 3 with the shaft of the engine 1 disconnected from the power coupling means 5 by the clutch 6. It is supposed to.
[0020]
The rotation speed of motor generator 2 is low when assisting engine 1 or driving an auxiliary machine (for example, about 800 rpm, which is the idling rotation speed of engine 1), but high when being rotated by engine 1. The engine 1 is rotated to the rotation speed (for example, the maximum rotation speed of the engine 1 is about 8000 rpm). If the induced voltage of the motor generator 2 during the co-rotation becomes higher than the voltage of the battery 17, the inverter 14 and the battery 17 may be damaged. Therefore, the control unit 13 controls to suppress the induced voltage by field weakening control or the like. ing.
[0021]
3 and 4 are a cross-sectional view and a vertical cross-sectional side view of the motor generator 2, respectively. In FIG. 3, the stator coil is omitted. The motor generator 2 is an IPM (Internal Permanent Magnet: embedded permanent magnet) type brushless motor from the viewpoints of preventing scattering of the permanent magnets at the time of high-speed rotation and utilizing reluctance torque.
[0022]
That is, the motor generator 2 includes a stator 20 in which a plurality of phases, for example, three-phase stator coils 20u, 20v, 20w are wound around a stator core 20a, and a permanent magnet made of ferrite such that the salient pole ratio is increased inside the rotor yoke 22a. And a rotor 22 having the embedded portion 21 embedded therein. The six plate-shaped permanent magnets 21 are embedded in the vicinity of the outer peripheral surface of the rotor yoke 22a along the axial direction so that the cross section has a hexagonal shape.
[0023]
The housing 23 of the motor generator 2 includes a substantially cup-shaped motor frame 24 and a bearing bracket 25 for closing an opening of the motor frame 24. A rotating shaft 28 of the rotor 22 is rotatably supported by a bearing 26 provided on a bottom wall of the motor frame 24 and a bearing 27 provided on a bearing bracket 25. A temperature sensor 29 composed of a thermistor, a thermocouple, or the like is attached to the outer wall of the motor frame 24.
[0024]
FIG. 1 shows a configuration of a vehicle motor system by functional blocks. The control device 30 includes a control unit 31, the inverter 14, the temperature sensor 29, and current sensors 32u, 32v, and 32w. Here, the inverter 14 is a power conversion unit having a well-known configuration in which switching elements such as IGBTs are connected in a three-phase bridge. The current sensors 32u, 32v, and 32w are configured by Hall CT, and detect currents flowing from the inverter 14 to the stator coils 20u, 20v, and 20w.
[0025]
The control unit 31 includes electronic components such as a DSP (Digital Signal Processor), a resistor, and a capacitor mounted on a substrate provided in the ECU 16. A control program for driving the motor generator 2 in the powering mode or the power generation mode is written in a nonvolatile memory built in the DSP or a nonvolatile memory added outside the DSP. The block configuration of the control unit 31 shown in FIG. 1 substantially represents functions realized by the control program. Hereinafter, the function of each block will be described.
[0026]
The control unit 31 is a control device based on a sensorless vector control method, and includes a three-phase-two-phase coordinate converter 33 and a two-phase-three-phase coordinate converter 34 for simultaneously performing rotation coordinate conversion and phase conversion. . The A / D converter 35 receives the voltage signals output from the current sensors 32u, 32v, and 32w and converts them into digital values to obtain detection currents Iu, Iv, and Iw. The three-phase / two-phase coordinate converter 33 calculates two-phase detection currents Id and Iq in the rotor coordinate system (dq coordinate system) from the three-phase detection currents Iu, Iv and Iw in the stator coordinate system. It has become.
[0027]
The estimator 36 estimates and calculates the rotation angle θ and the rotation speed ω of the rotor 22 based on the detection currents Id and Iq and command voltages Vdr and Vqr described later. Among them, the detected rotation angle θ is given to the three-phase / two-phase coordinate converter 33 and the two-phase / three-phase coordinate converter 34 described above.
[0028]
The control unit 31 is provided with a command rotation speed ωr of the motor generator 2 from another control unit (not shown) mounted on the vehicle. The speed controller 37 receives the rotation speed deviation Δω between the command rotation speed ωr calculated by the subtracter 38 and the detected rotation speed ω, and calculates the command currents Idr and Iqr by performing, for example, a PI calculation. is there.
[0029]
On the other hand, the temperature detector 39 (corresponding to temperature detecting means) receives the temperature signal output from the temperature sensor 29 and compensates for the non-linearity of the temperature sensor 29 to obtain the detected temperature Tm as a digital value. Things. The detected temperature Tm is the temperature of the outer wall portion of the motor frame 24, and shows a temperature change tendency similar to that of the permanent magnet 21.
[0030]
The current limiter 40 (corresponding to current limiting means) calculates the correction currents Idc and Iqc to be reduced based on the detected temperature Tm, and calculates the correction currents Idc and Iqc from the command currents Idr and Iqr, respectively. Subtracters 42 and 43 are provided to obtain corrected command currents Ids and Iqs by subtraction.
[0031]
The subtracters 44 and 45 subtract the detection currents Id and Iq from the command currents Ids and Iqs, respectively, to calculate current deviations ΔId and ΔIq. The current controller 46 inputs the current deviations ΔId and ΔIq, for example, PI The command voltages Vdr and Vqr are calculated by performing calculations and the like. The two-phase to three-phase coordinate converter 34 calculates three-phase command voltages Vur, Vvr, and Vwr in the stator coordinate system from the two-phase command voltages Vdr and Vqr in the rotor coordinate system. . Further, the PWM waveform shaper 47 compares these command voltages Vur, Vvr, Vwr with a carrier signal such as a triangular wave, and outputs drive signals Sup, Svp, Swp, Sun, Svn, and the like supplied to the gate of the IGBT constituting the inverter 14. Swn is generated.
[0032]
Next, the operation of the present embodiment will be described with reference to FIGS.
FIG. 5 shows an example of a BH curve (solid line) and a JH curve (dashed line) of ferrite which is a constituent material of the permanent magnet 21. Although four curves are drawn in each case, the data are obtained when the temperature of the permanent magnet 21 is −60 ° C., −20 ° C., + 20 ° C., and + 60 ° C. The BH curve shows the characteristic appearing outside the permanent magnet 21, and the JH curve shows the intensity of the magnetization inside the permanent magnet 21 (that is, unique to the permanent magnet 21).
[0033]
Generally, the temperature coefficient ΔBr / Br / ΔT of the ferrite magnet is about -0.18% / K, and the temperature coefficient of the coercive force HcJ is about +0.3 to + 0.5% / K. The permanent magnet 21 in the present embodiment has improved magnetic characteristics such as the temperature coefficient of coercive force, and the temperature coefficient ΔBr / Br / ΔT of the residual magnetic flux density Br is −0.18% / K. The temperature coefficient of the coercive force HcJ is + 0.18% / K. As the temperature decreases, the magnitude of the coercive force HcJ decreases.
[0034]
FIG. 6 schematically shows a temperature change of a BH curve of a ferrite magnet. As shown in FIG. 6, since the magnitude of the coercive force HcJ decreases with a decrease in temperature, demagnetization is easily caused. When a large current is applied to the motor and a large reverse magnetic field is applied to the motor when the ferrite magnet is at a low temperature, there is a risk of demagnetization.
[0035]
In the present embodiment, correlation data indicating the relationship between the temperature Tm of the outer wall of the motor frame 24 and the temperature Tp of the permanent magnet 21 is written in the non-volatile memory, and the current corrector 41 includes the temperature detector 39 Calculates the temperature Tp of the permanent magnet 21 based on the detected temperature Tm and the correlation data.
[0036]
As shown in FIGS. 5 and 6, since the change in the bending point due to the temperature change appears as a change in the coercive force HcJ, the current corrector 41 is equal to the reduction rate of the coercive force HcJ due to the temperature decrease. Alternatively, the command currents Ids and Iqs are reduced and controlled at a rate of more than that (+ 0.18% / K in the present embodiment). The data (+ 0.18% / K) of the rate of decrease in the magnitude of the coercive force HcJ due to the temperature drop is previously written in the nonvolatile memory.
[0037]
As shown in FIG. 6, since the demagnetization is less likely to occur when the temperature Tp of the permanent magnet 21 increases, the current limiter 40 sets the current only when the temperature Tp becomes equal to or lower than a predetermined set temperature. Perform limit control.
[0038]
As described above, according to the present embodiment, when the temperature Tp of the permanent magnet 21 falls below the set temperature and is likely to be demagnetized, the rate of reduction of the magnitude of the coercive force HcJ of the permanent magnet 21 is equal to that. As described above, the command currents Ids, Iqs, that is, the currents flowing through the stator coils 20u, 20v, 20w are reduced, so that the low-temperature demagnetization of the permanent magnet 21 can be reliably prevented. In particular, when the motor generator 2 operates in the powering mode so as to assist the engine 1 when the vehicle starts, a large current is applied to output a large torque. However, the occurrence of demagnetization is ensured by the current limiting control. Can be prevented. Further, even when the vehicle is used in winter or in a cold region, it is possible to prevent a reduction in driving force due to demagnetization, and to enhance the reliability of the vehicle motor system.
[0039]
Further, by the current limiting control, the drive current of the motor generator 2 is reduced as the environmental temperature of the vehicle is low and the performance of the battery 17 is likely to be reduced, so that the battery 17 is not overworked and the overall power supply of the vehicle is stabilized. Nature can be achieved.
[0040]
(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG.
FIG. 7 is a functional block diagram showing a configuration of a control device 48 for controlling the motor generator 2, and the same components as those in FIG. 1 are denoted by the same reference numerals. A switch circuit 50 (corresponding to an opening / closing means) is connected to one of the power lines 49p and 49n from the battery 17 to the inverter 14, and a resistor 51 is connected in parallel with the switch circuit 50. I have. The resistor 51 is screwed using an aluminum cover at a position as far as possible from the temperature sensor 29 on the outer wall of the motor frame 24 of the motor generator 2. The motor generator 2 includes position sensors 52u, 52v, and 52w configured by a Hall IC or the like.
[0041]
The control unit 53 controls the speed of the motor generator 2 by voltage control, and includes a voltage controller 54, a PWM waveform generator 47, a temperature detector 39, and an opening / closing controller 55. The voltage controller 54 receives the position signals Hu, Hv, and Hw output from the position sensors 52u, 52v, and 52w to obtain commutation timing, and calculates the rotational speed ω from the position signals Hu, Hv, and Hw. The command voltages Vur, Vvr, Vwr are directly generated by detecting and calculating the rotation speed deviation Δω, which is the result of subtraction between the command rotation speed ωr and the detected rotation speed ω, and output to the PWM waveform former 47. It has become.
[0042]
The opening / closing controller 55 (corresponding to opening / closing control means) estimates and calculates the temperature Tp of the permanent magnet 21 based on the detected temperature Tm obtained from the temperature detector 39 in the same manner as in the first embodiment. The maximum current flowing through the stator coils 20u, 20v, 20w is substantially determined by the maximum voltage of the battery 17, the constant of the motor generator 2, the command voltages Vur, Vvr, Vwr output by the voltage controller 54, and the like. The opening / closing controller 55 sets the switch circuit when the temperature Tp of the permanent magnet 21 is lower than a temperature (corresponding to a set temperature) at which demagnetization may occur due to a reverse magnetic field generated in the permanent magnet 21 due to the maximum current. Open 50.
[0043]
When the switch circuit 50 is in the open state, a voltage drop occurs in the resistor 51 and the input voltage of the inverter 14 decreases, and the output voltage of the inverter 14 also decreases accordingly. As a result, the current flowing through stator coils 20u, 20v, and 20w of motor generator 2 is reduced, and the magnitude of the reverse magnetic field is reduced, so that the occurrence of demagnetization can be prevented. In addition, since the resistor 51 generates heat and heats the motor generator 2, the temperature of the permanent magnet 21 in the motor generator 2 increases quickly, so that the permanent magnet 21 can quickly escape from a low-temperature state in which demagnetization is likely to occur. The power loss due to the current supply can be reduced as much as possible.
[0044]
The switch circuit 50 may be connected to the power supply line 49p, and the resistor 51 may be connected in parallel with the switch circuit 50. Further, a configuration may be employed in which a plurality of resistors 51 can be connected in series, and connection control may be performed such that the lower the temperature Tp of the permanent magnet 21, the greater the number of series connections.
[0045]
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG.
FIG. 8 is a functional block diagram showing a configuration of a control device 56 for controlling the motor generator 2, and the same components as those in FIGS. 1 and 7 are denoted by the same reference numerals. The present embodiment differs from the first and second embodiments described above in that a temperature sensor is not added to the motor generator 2. The vector control unit 57 that drives and controls the inverter 14 has a configuration in which the temperature detector 39 and the current limiter 40 are removed from the control unit 31 shown in FIG.
[0046]
A power switch 59 is connected to a power line 58 p extending from the battery 17 to the inverter 14, and a current limiting circuit 60 (corresponding to current limiting means) is connected between the power switch 59 and the inverter 14. The current limiting circuit 60 includes an N-channel type MOSFET 61 (corresponding to an opening / closing means) interposed in a power supply line 58n, a timer circuit 62, and a resistor 51 connected in parallel to the MOSFET 61. Here, the timer circuit 62 has a configuration of a CR integration circuit including resistors 63 and 64 connected in series between the power supply lines 58p and 58n, and a capacitor 65 and a Zener diode 66 connected in parallel with the resistor 64. are doing. The resistor 51 is attached to the motor frame 24 of the motor generator 2 in the same manner as in the second embodiment.
[0047]
Next, the operation of the control device 56 will be described.
When it becomes necessary to drive the motor generator 2 in the power running mode at the time of starting the vehicle or the like, a control unit (not shown) that integrally controls the engine 1 and the motor generator 2 turns on the power switch 59 and performs vector control. The command rotation speed ωr is given to the section 57. When the power switch 59 is turned on, the capacitor 65 is gradually charged via the resistor 63.
[0048]
While the terminal voltage of the capacitor 65 is lower than the threshold voltage Vth of the MOSFET 61, the MOSFET 61 holds the off state, a voltage drop occurs in the resistor 51, and the input voltage of the inverter 14 decreases. Output voltage and output current are also reduced. When the delay time of the timer circuit 62 elapses and the terminal voltage of the capacitor 65 becomes equal to or higher than the threshold voltage Vth of the MOSFET 61, the MOSFET 61 turns from off to on, so that no voltage loss occurs in the resistor 51 thereafter. .
[0049]
For example, when the operation of a vehicle that has been left for a while is started, the temperature of the permanent magnet 21 of the motor generator 2 often drops to the ambient temperature. According to the present embodiment, when the power switch 59 is turned on in such a low temperature state, the inverter is kept on until the delay time corresponding to the temperature at which the permanent magnet 21 rises to a temperature at which the permanent magnet 21 is hardly demagnetized has elapsed. Since the output current of No. 14 can be reduced, the magnitude of the reverse magnetic field can be suppressed to prevent the occurrence of demagnetization. Further, since a temperature sensor is not required, the motor generator 2 conventionally used can be used as it is. Further, when power is turned on, there is also an effect of suppressing an inrush current to a capacitor provided at the input section of the inverter 14.
[0050]
(Other embodiments)
The present invention is not limited to the embodiments described above and shown in the drawings. For example, the present invention can be modified or expanded as follows.
Temperature sensor 29 may be provided inside housing 23 of motor generator 2. Further, the number of the temperature sensors 29 is not limited to one, but may be plural. In this case, it is most preferably provided at a position where the temperature becomes the same as the temperature of the permanent magnet 21, but it may be provided at a position showing a temperature change that is close to the temperature change of the permanent magnet 21.
[0051]
In the first and third embodiments, the position sensors 52u, 52v, and 52w may be provided in the motor generator 2 as in the second embodiment. Further, the rotor of motor generator 2 may have a structure in which permanent magnets are provided on the surface. In the second embodiment, the current sensors 32u, 32v, and 32w may be provided to perform vector control. Further, in the third embodiment, the delay time may be generated by using a timer function built in the DSP.
[0052]
【The invention's effect】
As is apparent from the above description, the control device for a vehicle-mounted motor according to the present invention has a large coercive force due to a decrease in the temperature of the permanent magnet when the detected temperature of the permanent magnet of the vehicle-mounted motor is lower than a predetermined set temperature. Since the current flowing through the stator coil is reduced at a rate equal to or greater than the reduction rate, the reverse magnetic field acting on the permanent magnet is reduced, and low-temperature demagnetization can be reliably prevented.
[Brief description of the drawings]
FIG. 1 is a functional block diagram of a vehicle motor system according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a schematic configuration of a drive system of a hybrid vehicle.
FIG. 3 is a sectional view of a motor generator.
FIG. 4 is a longitudinal sectional side view of a motor generator.
FIG. 5 is a diagram showing a BH curve and a JH curve of ferrite.
FIG. 6 is a diagram showing a temperature change of a BH curve of ferrite.
FIG. 7 is a view corresponding to FIG. 1, showing a second embodiment of the present invention;
FIG. 8 is a view corresponding to FIG. 1, showing a third embodiment of the present invention;
[Explanation of symbols]
2 is a motor generator (vehicle motor), 14 is an inverter (power conversion means), 20 is a stator, 20u, 20v, 20w are stator coils (coils), 21 is a permanent magnet, 22 is a rotor, 29 is a temperature sensor, , 48 and 56 are control devices, 39 is a temperature detector (temperature detecting means), 40 is a current limiter (current limiting means), 50 is a switch circuit (opening / closing means), 51 is a resistor, and 55 is an opening / closing controller ( Switching control means), 60 is a current limiting circuit (current limiting means), 61 is a MOSFET (opening / closing means), and 62 is a timer circuit (opening / closing control means).

Claims (6)

An in-vehicle motor having a stator with a coil wound thereon and a rotor provided with permanent magnets on the surface or inside can be driven in a power generation mode in which it rotates by obtaining torque from the outside or in a power running mode in which it generates and rotates itself. In the control device of the in-vehicle motor to be controlled,
A temperature sensor attached to the vehicle motor,
Temperature detecting means for detecting the temperature of the permanent magnet based on the output signal of the temperature sensor;
A current limit for reducing the current flowing through the coil at a rate equal to or greater than the rate of reduction in the magnitude of the coercive force due to the temperature drop of the permanent magnet when the detected temperature of the permanent magnet is lower than a predetermined set temperature; And a control device for a vehicle-mounted motor. An in-vehicle motor having a stator with a coil wound thereon and a rotor provided with permanent magnets on the surface or inside can be driven in a power generation mode in which it rotates by obtaining torque from the outside or in a power running mode in which it generates and rotates itself. In the control device of the in-vehicle motor to be controlled,
A temperature sensor attached to the vehicle motor,
Temperature detecting means for detecting the temperature of the permanent magnet based on the output signal of the temperature sensor;
Power conversion means for inputting a voltage from an external power supply and outputting an AC voltage to the coil,
Switching means connected between the external power supply and the power conversion means,
A resistor connected in parallel with the switching means;
An on-off control unit for controlling the on-off unit to open under a condition that the detected temperature of the permanent magnet is lower than a predetermined set temperature. An in-vehicle motor having a stator with a coil wound thereon and a rotor provided with permanent magnets on the surface or inside can be driven in a power generation mode in which it rotates by obtaining torque from the outside or in a power running mode in which it generates and rotates itself. In the control device of the in-vehicle motor to be controlled,
A current limiting unit that reduces a current flowing through the coil to a predetermined current value during a period from the start of the vehicle motor to the elapse of a predetermined delay time. Motor control device. Power conversion means for inputting a voltage from an external power supply and outputting an AC voltage to the coil,
The current limiting means,
Switching means connected between the external power supply and the power conversion means,
A resistor connected in parallel with the switching means;
An opening / closing control unit configured to open the opening / closing unit until the delay time elapses, and to switch the opening / closing unit to a closed state on condition that the delay time elapses. Item 4. An in-vehicle motor control device according to item 3. The control device for a vehicle-mounted motor according to claim 2, wherein the resistor is attached to the vehicle-mounted motor. An in-vehicle motor used as a vehicle power source having a stator wound with coils and a rotor provided with permanent magnets on the surface or inside,
A motor system for a vehicle, comprising: the control device for a vehicle-mounted motor according to any one of claims 1 to 5.

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