JP4304842B2 - Motor driving apparatus and motor driving method - Google Patents

Motor driving apparatus and motor driving method Download PDF

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Publication number
JP4304842B2
JP4304842B2 JP2000232003A JP2000232003A JP4304842B2 JP 4304842 B2 JP4304842 B2 JP 4304842B2 JP 2000232003 A JP2000232003 A JP 2000232003A JP 2000232003 A JP2000232003 A JP 2000232003A JP 4304842 B2 JP4304842 B2 JP 4304842B2
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Prior art keywords
temperature
inverter
torque
value
motor
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JP2002051583A (en
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中村  秀男
幸弘 峯澤
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アイシン・エィ・ダブリュ株式会社
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/60Other road transportation technologies with climate change mitigation effect
    • Y02T10/64Electric machine technologies for applications in electromobilty
    • Y02T10/642Control strategies of electric machines for automotive applications
    • Y02T10/644Control strategies for ac machines other than vector control
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/60Other road transportation technologies with climate change mitigation effect
    • Y02T10/72Electric energy management in electromobility
    • Y02T10/7208Electric power conversion within the vehicle
    • Y02T10/7241DC to AC or AC to DC power conversion
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/60Other road transportation technologies with climate change mitigation effect
    • Y02T10/72Electric energy management in electromobility
    • Y02T10/7258Optimisation of vehicle performance
    • Y02T10/7275Desired performance achievement

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor driving device and a motor driving method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an electric vehicle, a motor including a stator having U-phase, V-phase, and W-phase stator coils, and a rotor that is rotatably disposed inside the stator and has a magnetic pole pair is used. The motor is driven by supplying U-phase, V-phase, and W-phase currents to the stator coil by a driving device.
[0003]
Then, when a vehicle control circuit that controls the entire electric vehicle calculates a torque command value, calculates a current command value based on the torque command value, and sends it to the motor control unit, the motor control unit U-phase, V-phase, and W-phase pulse width modulation signals having a pulse width corresponding to the current command value are generated, and the pulse width modulation signal is sent to the drive circuit.
[0004]
The drive circuit generates a switching signal corresponding to the pulse width modulation signal, and sends the switching signal to the inverter. The inverter includes six transistors serving as switching elements. The inverter is turned on only when the switching signal is on to generate a current of each phase, and the current of each phase is supplied to the stator coil.
[0005]
In this way, by operating the motor control unit, the motor can be driven to generate motor torque, and the motor torque can be transmitted to the drive wheels to drive the electric vehicle.
[0006]
Since the stator coil of the motor is star-connected, when the values of the currents of the two phases, for example, the U-phase and the V-phase, are determined, the remaining one phase, for example, W The value of the phase current is also determined. Therefore, in order to control the current of each phase, the currents of the U phase and V phase are detected by the current sensor. Feedback control is performed on a dq axis model in which the d axis is taken in the direction of the magnetic pole pair of the rotor and the q axis is taken in a direction perpendicular to the d axis.
[0007]
Therefore, in the motor control unit, the U-phase and V-phase currents undergo three-phase / two-phase conversion to become d-axis current and q-axis current. Then, a d-axis current deviation between the d-axis current and the d-axis current command value and a q-axis current deviation between the q-axis current and the q-axis current command value are respectively calculated, and the d-axis current deviation and the q-axis current deviation are calculated. A d-axis voltage command value and a q-axis voltage command value are generated so as to be zero (0). Subsequently, the d-axis voltage command value and the q-axis voltage command value are converted into U-phase, V-phase, and W-phase voltage command values by performing two-phase / three-phase conversion, and based on the voltage command values of the respective phases. Thus, U-phase, V-phase, and W-phase pulse width modulation signals are generated.
[0008]
By the way, when the transistor is selectively switched, that is, turned on and off, heat is generated, so the transistor is cooled by a heat sink. If the transistor cannot be cooled sufficiently, the characteristics of the transistor Not only decreases, but also durability of the transistor decreases. Therefore, a temperature sensor is disposed at a predetermined location in the inverter, the temperature of the inverter is detected by the temperature sensor, and when the detected temperature, that is, the actual temperature exceeds a threshold value, the inverter An abnormality is detected, and the limit value of the torque command value, that is, the limit torque is reduced, so that the temperature of the transistor is lowered.
[0009]
[Problems to be solved by the invention]
However, in the conventional motor drive device, the temperature sensor is disposed at a predetermined location in the inverter and only detects the temperature of the inverter locally, so it cannot reliably detect the abnormality of the inverter. . For example, when the drive circuit generates a switching signal and sends the switching signal to the inverter, if the rotor does not rotate for some reason, that is, if a stall condition occurs, only a predetermined transistor is turned on. However, if the temperature sensor is disposed at a position away from the predetermined transistor, the actual temperature does not increase. Therefore, the abnormality of the inverter cannot be detected with certainty, so that the limit torque cannot be reduced and the temperature of the transistor may not be lowered.
[0010]
In addition, when the motor torque required for running an electric vehicle, such as when starting up, running on an uphill, or suddenly accelerating, that is, when the required torque is large, the temperature of each transistor increases rapidly, and the temperature of the inverter also increases. It becomes high rapidly. However, the temperature sensor cannot sufficiently follow the temperature rise and has low responsiveness. Therefore, an abnormality of the inverter cannot be detected quickly, so that it is delayed to reduce the limit torque, and it is delayed to lower the temperature of the transistor.
[0011]
An object of the present invention is to provide a motor driving apparatus and a motor driving method that can solve the problems of the conventional motor driving apparatus and reliably and quickly detect an abnormality in an inverter.
[0012]
[Means for Solving the Problems]
  Therefore, in the motor drive device of the present invention, a power source, a motor, and an inverter that converts a current supplied from the power source into a phase current and supplies the phase motor to the motor when the switching element is switched, and the inverter Inverter temperature detection means for detecting the local temperature at the predetermined location as the actual temperature of the inverter, the actual temperature detected at a predetermined timing, and the actual temperature as the inverter state Based on the temperature correction value for correction corresponding to the estimated temperature calculation processing means for calculating the estimated temperature representing the entire temperature of the inverter, and the continuous stall time representing that the inverter is in the stalled state A first torque limit value based on the estimated temperature based on the stall time calculation processing means and the continuous stall time; And the second torque limit value is calculated based on the actual temperature, the third torque limit value is calculated, and the minimum value of the first to third torque limit values is calculated as the limit torque. Means.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0019]
FIG. 1 is a functional block diagram of a motor drive device according to an embodiment of the present invention.
[0020]
In the figure, reference numeral 14 denotes a battery as a power source, 31 denotes a motor, 40 denotes switching of a transistor (not shown) as a switching element, and a current supplied from the power source 14 is converted into a phase current and supplied to the motor 31. An inverter, 22 is a temperature sensor as inverter temperature detecting means for detecting the temperature of the inverter 40 as an actual temperature, 91 is a state value calculation processing means for calculating a state value representing the state of the inverter 40, and 92 is the actual temperature and Limiting torque calculation processing means for calculating a limiting torque based on one of the state values.
[0021]
FIG. 2 is a conceptual diagram of a motor driving device according to the embodiment of the present invention, and FIG. 3 is a block diagram of a motor control unit according to the embodiment of the present invention.
[0022]
In the figure, 10 is a motor drive device, 17 is a vehicle control circuit that controls the entire electric vehicle, 31 is a motor, and 45 is a motor control unit that controls the motor 31. Note that a DC brushless motor is used as the motor 31. The motor 31 includes a rotor (not shown) disposed rotatably, and a stator disposed radially outward from the rotor. The stator includes a stator core and a U phase wound around the stator core, V Phase and W phase stator coils 11 to 13 are provided.
[0023]
In order to drive the motor 31 by driving the motor 31, a direct current from the battery 14 as a power source is supplied to the inverter 40 via the main relay 15, and the U phase as a phase current is supplied by the inverter 40. , V-phase and W-phase currents IU, IV, IWAnd the current I of each phaseU, IV, IWAre respectively supplied to the stator coils 11 to 13.
[0024]
For this purpose, the inverter 40 includes transistors Tr1 to Tr6 as six switching elements, and each of the transistors Tr1 to Tr6 is turned on / off to thereby turn on the current I of each phase.U, IV, IWCan be generated.
[0025]
In addition, a drum (not shown) is attached to the shaft of the rotor, a small magnet is attached to the drum, and a magnetoresistive element as a simple magnetic pole position sensor, for example, a hall element 43 is disposed to face the drum. The Hall element 43 detects the position of the small magnet as the rotor rotates, and detects the position as a sensor output at every predetermined angle (60 [°] in the present embodiment). Signal PU, PV, PWIs sent to a magnetic pole position detection circuit 44 as magnetic pole position detection means. Then, the magnetic pole position detection circuit 44 receives the position detection signal P.U, PV, PWIn response, the magnetic pole position θ is detected, a detection pulse is generated, and the magnetic pole position θ and the detection pulse are sent to the motor control unit 45. Further, a capacitor 20 is disposed between the main relay 15 and the inverter 40. The capacitor 20 is charged when an ignition key (not shown) is turned on and is turned on when the main relay 15 is turned on, and is applied to the inverter 40. Smoothes the applied voltage. A positive polarity terminal and a negative polarity terminal of the capacitor 20 are connected to the DC voltage detection circuit 16, and the DC voltage detection circuit 16 is a voltage between the terminals of the capacitor 20, that is, a DC voltage VCAnd the DC voltage VCIs sent to the vehicle control circuit 17 and the motor control unit 45. Further, upon receiving the detection pulse from the magnetic pole position detection circuit 44, the motor control unit 45 calculates the rotation speed of the motor 31, that is, the motor rotation speed Nm based on the timing of each detection pulse, and the vehicle control circuit 17 Send to. The vehicle control circuit 17 detects a vehicle speed V corresponding to the motor rotation speed Nm.
[0026]
By the way, since the stator coils 11 to 13 are star-connected, when the current values of two phases, for example, the U phase and the V phase, are determined, the remaining one phase, for example, the W phase is determined. The current value is also determined. Therefore, the current I of each phaseU, IV, IWTo control the U-phase and V-phase currents IU, IVCurrent sensors 33 and 34 are disposed on the lead wires of the stator coils 11 and 12, and a detection signal SG as a sensor output of the current sensors 33 and 34 is detected.U, SGVIs sent to the motor control unit 45.
[0027]
An accelerator sensor 18 is disposed on an accelerator pedal (not shown). When the driver depresses the accelerator pedal, the accelerator sensor 18 detects the depression amount of the accelerator pedal, that is, the accelerator opening α, and controls the vehicle. Send to circuit 17.
[0028]
A command value generation unit (not shown) of the vehicle control circuit 17 generates a torque command value Tm based on the accelerator opening α, the vehicle speed V, etc. sent from the accelerator sensor 18, and uses the torque command value Tm as a motor control unit. 45. The motor control unit 45 generates a d-axis current command value i as a current command value Im based on the torque command value Tm.dsAnd q-axis current command value iqsIs generated. The motor control unit 45 then detects the magnetic pole position θ and the detection signal SG.U, SGV, D-axis current command value idsAnd q-axis current command value iqsThe pulse width is calculated on the basis of the pulse width modulation signal S of U phase, V phase and W phase having the pulse width.U, SV, SWAnd the pulse width modulation signal S of each phaseU, SV, SWIs sent to the drive circuit 51. The drive circuit 51 includes a pulse width modulation signal S for each phase.U, SV, SWIn response, switching signals are generated as six drive signals for driving the transistors Tr1 to Tr6, and the switching signals are sent to the inverter 40. The inverter 40 turns on the transistors Tr1 to Tr6 only while the switching signal is on to turn on the current IU, IV, IWEach current IU, IV, IWIs supplied to each of the stator coils 11-13. Thus, the electric vehicle can be run by driving the motor 31. In the present embodiment, a motor 31 is provided for each drive wheel, and six transistors Tr1 to Tr6 are provided corresponding to each motor 31.
[0029]
The motor control unit 45 performs feedback control by vector control calculation on a dq axis model in which the d axis is taken in the direction of the magnetic pole pair of the rotor and the q axis is taken in a direction perpendicular to the d axis. It has come to be.
[0030]
For this purpose, the detection signal SG sent from the current sensors 33, 34 in the motor control unit 45.U, SGVAnd the magnetic pole position θ is sent to the UV-dq converter 61. The UV-dq converter 61 detects the detection signal SG.U, SGVAnd three-phase / two-phase conversion based on the magnetic pole position θ, and the detection signal SGU, SGVAnd the magnetic pole position θ with the d-axis current idAnd q-axis current iqConvert to
[0031]
And d-axis current idIs sent to the subtractor 62, where the d-axis current idAnd d-axis current command value idsD-axis current deviation ΔidIs calculated, and the d-axis current deviation ΔidIs sent to the d-axis voltage command value generator 64. On the other hand, q-axis current iqIs sent to the subtractor 63, where the q-axis current iqAnd q-axis current command value iqsQ-axis current deviation ΔiqIs calculated, and the q-axis current deviation ΔiqIs sent to the q-axis voltage command value generation unit 65. The d-axis voltage command value generator 64 and the q-axis voltage command value generator 65 constitute a voltage command value generator.
[0032]
The d-axis voltage command value generator 64 and the q-axis voltage command value generator 65 are connected to the q-axis inductance L sent from the parameter calculator 71.qAnd d-axis inductance LdAnd the d-axis current deviation ΔidAnd q-axis current deviation ΔiqD-axis current deviation ΔidAnd q-axis current deviation ΔiqD-axis voltage command value V as the inverter output on the two axes so that becomes zerod *And q-axis voltage command value Vq *And d-axis voltage command value Vd *And q-axis voltage command value Vq *Are sent to the dq-UV converter 67, respectively.
[0033]
Subsequently, the dq-UV converter 67 receives the d-axis voltage command value Vd *Q-axis voltage command value Vq *And two-phase / three-phase conversion based on the magnetic pole position θ and the d-axis voltage command value Vd *And q-axis voltage command value Vq *U-phase, V-phase and W-phase voltage command values VU *, VV *, VW *The voltage command value V of each phaseU *, VV *, VW *To the PWM generator 68. The PWM generator 68 generates a voltage command value V for each phase.U *, VV *, VW *And the DC voltage VCBased on the pulse width modulation signal S of each phaseU, SV, SWIs generated.
[0034]
By the way, since heat is generated when the transistors Tr1 to Tr6 are turned on / off, the transistors Tr1 to Tr6 are cooled by a heat sink (not shown), but the transistors Tr1 to Tr6 cannot be sufficiently cooled. Further, not only the characteristics of the transistors Tr1 to Tr6 are degraded, but also the durability of the transistors Tr1 to Tr6 is degraded. Therefore, a temperature sensor 22 as an inverter temperature detecting means is disposed at a predetermined location in the inverter 40, and when the actual temperature of the inverter 40 detected by the temperature sensor 22 exceeds a threshold value, an abnormality of the inverter 40 is detected. It is conceivable to lower the temperature of the inverter 40 by detecting and reducing the limit torque.
[0035]
However, since the temperature sensor 22 is disposed at a predetermined location in the inverter 40 and only detects the temperature of the inverter 40 locally, when the temperature of the inverter 40 becomes locally high, the inverter 40 It is impossible to reliably detect abnormalities. That is, for example, if the drive circuit 51 generates a switching signal and sends the switching signal to the inverter 40, but a stall condition occurs for some reason, only a predetermined transistor remains on. Although the temperature of the inverter 40 is locally increased, if the temperature sensor 22 is disposed at a position away from the predetermined transistor, the actual temperature does not increase. In that case, the abnormality of the inverter 40 cannot be detected, and the limit torque cannot be reduced.
[0036]
In addition, when the required torque is large, such as when starting, traveling uphill, or during rapid acceleration, the temperature of each of the transistors Tr1 to Tr6 increases rapidly, and the temperature of the inverter 40 also increases rapidly. However, the temperature sensor 22 cannot sufficiently follow the rise in temperature and has low responsiveness. Therefore, since the abnormality of the inverter 40 cannot be detected quickly, it is delayed to reduce the limit torque, and the temperature of the inverter 40 is delayed to be lowered.
[0037]
Therefore, in the present embodiment, by detecting the abnormality of the inverter 40 by a plurality of abnormality determination methods and reducing the limit torque so that the abnormality of the inverter 40 can be reliably and quickly detected. The temperature of the transistors Tr1 to Tr6 is lowered.
[0038]
Next, the operation of the motor drive device 10 will be described.
[0039]
FIG. 4 is a main flowchart showing the operation of the motor driving apparatus according to the embodiment of the present invention, FIG. 5 is a diagram showing a subroutine of estimated temperature calculation processing in the embodiment of the present invention, and FIG. 6 is in the embodiment of the present invention. FIG. 7 is a diagram showing a subroutine of estimated temperature coefficient calculation processing, FIG. 7 is a diagram showing a subroutine of heat dissipation amount calculation processing in the embodiment of the present invention, and FIG. 8 is a diagram showing subroutine of offset temperature calculation processing in the embodiment of the present invention. FIG. 9 is a first diagram for explaining the motor rotation speed / required torque area in the embodiment of the present invention, FIG. 10 is a diagram showing a subroutine for stall determination processing in the embodiment of the present invention, and FIG. FIG. 12 shows a subroutine of limit torque calculation processing in the embodiment of the invention, and FIG. 12 shows the operation of the stall determination processing in the embodiment of the invention FIG. 13 is a diagram showing the relationship between the second torque limit value and the estimated temperature in the embodiment of the present invention, and FIG. 14 is the third torque limit value and the actual temperature in the embodiment of the present invention. It is a figure which shows the relationship. In FIG. 9, the horizontal axis represents the motor rotation speed Nm, the vertical axis represents the required torque Tn, the horizontal axis represents the estimated temperature te, the vertical axis represents the second torque limit value ρ2, and FIG. The horizontal axis represents the actual temperature, and the vertical axis represents the third torque limit value ρ3.
[0040]
First, required torque calculation processing means (not shown) of the vehicle control circuit 17 (FIG. 2) performs required torque calculation processing, and calculates required torque based on the accelerator opening α, the vehicle speed V, etc. sent from the accelerator sensor 18. The required torque is sent to the motor control unit 45 as a torque command value Tm. Here, the required torque is a value obtained by converting the output value of the motor torque into a torque command value.
[0041]
Subsequently, the estimated temperature calculation processing means 93 of the motor control unit 45 performs an estimated temperature calculation process, and estimates by calculating the entire temperature of the inverter 40 as the estimated temperature te. The estimated temperature te constitutes a state value representing the state of the inverter 40, and the estimated temperature calculation processing means 93 constitutes a state value calculation processing means 91 (FIG. 1). Then, the stall determination processing means 94 of the motor control unit 45 performs a stall determination process to determine whether or not a stall condition has occurred. Subsequently, the limit torque calculation processing unit 92 of the motor control unit 45 performs a limit torque calculation process, and calculates the limit torque based on the estimated temperature te calculated by the estimated temperature calculation process and the determination result by the stall determination process. calculate.
[0042]
Then, the target torque calculation processing means 95 of the motor control unit 45 performs target torque calculation processing, determines whether or not the torque command value Tm is greater than the limit torque, and if the torque command value Tm is greater than the limit torque. The limit torque is calculated as the target torque, and when the torque command value Tm is equal to or less than the limit torque, the torque command value Tm is calculated as the target torque. Subsequently, the current command value calculation processing means 96 of the motor control unit 45 performs a current command value calculation process, and based on the target torque and the like, the d-axis current command value idsAnd q-axis current command value iqsIs calculated.
[0043]
Next, a flowchart will be described.
Step S1: A torque command value Tm is calculated.
Step S2: Estimated temperature calculation processing is performed.
Step S3 Stall determination processing is performed.
Step S4: Limit torque calculation processing is performed.
Step S5: It is determined whether the torque command value Tm is greater than the limit torque. If the torque command value Tm is greater than the limit torque, the process proceeds to step S7. If the torque command value Tm is equal to or less than the limit torque, the process proceeds to step S6.
Step S6: The torque command value Tm is set as the target torque.
Step S7: Limit torque is set to the target torque.
Step S8: d-axis current command value i as current command value ImdsAnd q-axis current command value iqsIs calculated and the process is terminated.
[0044]
Subsequently, a subroutine of the estimated temperature calculation process in step S2 of FIG. 4 will be described.
[0045]
In calculating the estimated temperature te, a predetermined timing, in this embodiment, a time when estimation of the estimated temperature te is started, that is, an estimation start time is specified, and an actual temperature detected by the temperature sensor 22 at the estimation start time That is, the estimated start temperature tmSTIs recorded in a memory (not shown) in the motor control unit 45. The estimated temperature te corresponds to the state of the inverter 40, and the estimated start temperature tmST, Calculated based on the offset temperature to due to heat potentially held by the inverter 40 at the estimation start time and the integrated value Ad representing the heat balance of the inverter 40 from the estimation start time to the present, It is expressed as 1). In this case, the first temperature correction value is constituted by the offset temperature to, and the second temperature correction value is constituted by the integrated value Ad.
[0046]
te = tmST+ To + Ad (1)
The integrated value Ad is calculated on the basis of the heat generation amount Q accompanying the on / off of the transistors Tr1 to Tr6 and the heat dissipation amount R from the inverter 40, and is calculated from the heat generation amount Q as shown in the following equation (2). The value obtained by subtracting the heat radiation amount R is represented by a value obtained by integrating the time from the estimation start time to the present time.
[0047]
Ad = ∫ (Q−R) dt (2)
Therefore, the estimated temperature te is expressed as the following equation (3).
[0048]
te = tmST+ To + ∫ (Q-R) dt (3)
When the estimated temperature coefficient is K and the required torque is Tn, the calorific value Q is
Q = K ・ Tn2
Therefore, the estimated temperature te is expressed as the following equation (4).
[0049]
te = tmST+ To + ∫ (K ・ Tn2-R) dt (4)
The heat radiation amount R and the estimated temperature coefficient K are set in advance for each of the areas AR1 to AR6 shown in FIG.
[0050]
The estimated temperature calculation processing means 93 reads the torque command value Tm and calculates the estimated start temperature tm.STIs read from memory. Subsequently, the estimated temperature coefficient calculation processing means (not shown) of the estimated temperature calculation processing means 93 calculates the estimated temperature coefficient K by performing the estimated temperature coefficient calculation processing, and the estimated temperature calculation processing means 93 does not show the heat dissipation amount (not shown). The calculation processing means calculates a heat dissipation amount R by performing a heat dissipation amount calculation process, and an offset temperature calculation processing means (not shown) of the estimated temperature calculation processing means 93 calculates an offset temperature to by performing an offset temperature calculation process. To do.
[0051]
When the estimated temperature coefficient K, the heat radiation amount R, and the offset temperature to are calculated in this way, the estimated temperature calculation processing means 93 performs an estimated temperature calculation process, and the request expressed by the torque command value Tm. Torque Tn, estimated start temperature tmSTBased on the estimated temperature coefficient K, the heat radiation amount R, and the offset temperature to, the estimated temperature te is calculated by the equation (4).
[0052]
Therefore, the temperature sensor 22 is only disposed at a predetermined location in the inverter 40, and an abnormality of the inverter 40 can be detected even when the temperature of the inverter 40 is locally increased. That is, in the present embodiment, the overall temperature of the inverter 40 can be estimated from the estimated temperature te, so that an abnormality of the inverter 40 can be reliably detected. Therefore, the limit torque can be reduced and the temperature of the inverter 40 can be lowered.
[0053]
The offset temperature calculation processing means and the integrated value calculation processing means (not shown) of the estimated temperature calculation processing means 93 for calculating the integrated value Ad constitute a temperature correction value calculation processing means, and the offset temperature calculation processing means The first temperature correction value calculation processing means constitutes the second temperature correction value calculation processing means.
[0054]
In the present embodiment, the required torque Tn is used to calculate the calorific value Q, but the motor torque generated by the motor 31 can be used instead of the required torque Tn. In that case, the value of the estimated temperature coefficient K is changed.
[0055]
Next, a flowchart will be described.
Step S2-1: The torque command value Tm is read.
Step S2-2 Estimated start temperature tmSTIs read.
Step S2-3 An estimated temperature coefficient calculation process is performed.
Step S2-4 A heat release amount calculation process is performed.
Step S2-5: Perform offset temperature calculation processing.
Step S2-6: Calculate the estimated temperature te and return.
[0056]
Next, a subroutine for the estimated temperature coefficient calculation process in step S2-3 in FIG. 5 will be described.
[0057]
In this case, the estimated temperature coefficient K is preset for each region to which the motor rotation speed Nm and the required torque Tn belong, and the motor rotation speed Nm, the required torque Tn and the estimated temperature coefficient K are associated in the memory as a table. To be recorded.
[0058]
First, the estimated temperature coefficient calculation processing means determines that the motor rotation speed Nm is a first motor rotation speed threshold Nm.TH1. In the present embodiment, a first required torque threshold value Tn that is lower than 20 [rpm] and that the absolute value | Tn | of the required torque Tn is preset according to the rating of the motor 31.TH1. In the present embodiment, it is determined whether it belongs to the area AR1 shown in FIG. 9, which is larger than 20% of the maximum torque. When the motor rotation speed Nm and the absolute value | Tn | belong to the area AR1, the estimated temperature coefficient calculation processing unit sets the estimated temperature coefficient K to a value k1.
[0059]
Further, the estimated temperature coefficient calculation processing means, when the motor rotation speed Nm and the absolute value | Tn | do not belong to the area AR1, the motor rotation speed Nm is 20 [rpm] or more and the absolute value | Tn | Second required torque threshold TnTH2 (TnTH2> TnTH1) In the present embodiment, it is 80% or more of the maximum torque, and the third required torque threshold TnTH3 (TnTH3> TnTH2) In the present embodiment, it is determined whether or not it belongs to the area AR2 smaller than 90% of the maximum torque. When the motor rotation speed Nm and the absolute value | Tn | belong to the area AR2, the estimated temperature coefficient calculation processing means sets the estimated temperature coefficient K to the value k2.
[0060]
Further, the estimated temperature coefficient calculation processing means, when the motor rotation speed Nm and the absolute value | Tn | do not belong to the areas AR1 and AR2, the motor rotation speed Nm is 20 rpm or more and the absolute value | Tn It is determined whether or not | belongs to the area AR3 that is 90% or more of the maximum torque. When the motor rotation speed Nm and the absolute value | Tn | belong to the area AR3, the estimated temperature coefficient calculation processing means sets the estimated temperature coefficient K to a value k3.
[0061]
The estimated temperature coefficient calculation processing means sets the estimated temperature coefficient K to zero when the motor rotation speed Nm and the absolute value | Tn | do not belong to the areas AR1 to AR3. The values k1 to k3 are
k1> k2> k3
To be.
[0062]
As described above, in the estimated temperature coefficient calculation process, when the motor rotation speed Nm is lower than 20 [rpm], a large amount of heat generation Q is assumed by setting the value k1 large, and the motor rotation speed Nm is 20 [rpm. When the absolute value | Tn | is 80% or more of the maximum torque and smaller than 90%, the calorific value Q is assumed to be small by setting the value k2 small. When | Tn | is 90% or more of the maximum torque, it is assumed that the heat generation amount Q is further reduced by setting the value k3 to be smaller, and otherwise the heat generation amount Q is assumed to be zero. ing. In FIG. 9, V is the vehicle speed, LTIs the limiting torque.
[0063]
Next, a flowchart will be described.
Step S2-3-1: It is determined whether the motor rotational speed Nm is lower than 20 [rpm] and the absolute value | Tn | is larger than 20 [%] of the maximum torque. When the motor rotational speed Nm is lower than 20 [rpm] and the absolute value | Tn | is larger than 20 [%] of the maximum torque, the motor rotational speed Nm is 20 [rpm] or more in step S2-3-2. If the absolute value | Tn | is 20% or less of the maximum torque, the process proceeds to step S2-3-3.
Step S2-3-2: The value k1 is set to the estimated temperature coefficient K, and the process returns.
Step S2-3-3: It is determined whether or not the motor rotation speed Nm is 20 [rpm] or more and the absolute value | Tn | is 80 [%] or more of the maximum torque and smaller than 90 [%]. When the motor rotation speed Nm is 20 [rpm] or more and the absolute value | Tn | is 80 [%] or more of the maximum torque and smaller than 90 [%], the motor rotation speed is determined in Step S2-3-4. When Nm is lower than 20 [rpm] and the absolute value | Tn | is 90 [%] or more of the maximum torque or smaller than 80 [%], the process proceeds to step S2-3-5.
Step S2-3-4: The value k2 is set in the estimated temperature coefficient K, and the process returns.
Step S2-3-5: It is determined whether the motor rotation speed Nm is 20 [rpm] or more and the absolute value | Tn | is 90 [%] or more of the maximum torque. When the motor rotation speed Nm is 20 [rpm] or more and the absolute value | Tn | is 90 [%] or more of the maximum torque, the motor rotation speed Nm is set to 20 [rpm] in step S2-3-6. If the absolute value | Tn | is smaller than 90% of the maximum torque, the process proceeds to step S2-3-7.
Step S2-3-6: Sets the value k3 to the estimated temperature coefficient K, and returns.
Step S2-3-7: The estimated temperature coefficient K is set to zero and the process returns.
[0064]
Next, a subroutine for the heat radiation amount calculation process in step S2-4 in FIG. 5 will be described.
[0065]
In this case, a heat release amount R is preset for each region to which the motor rotation speed Nm and the required torque Tn belong, and the motor rotation speed Nm, the required torque Tn and the heat release amount R are associated in the memory and recorded as a table. The
[0066]
Then, the heat radiation amount calculation processing means determines whether or not the absolute value | Tn | belongs to the area AR4 shown in FIG. 9, which is 20% or less of the maximum torque. When the absolute value | Tn | belongs to the area AR4, the heat dissipation amount calculation processing means sets the heat dissipation amount R to a value q.
[0067]
Subsequently, when the absolute value | Tn | does not belong to the area AR4, the heat dissipation amount calculation processing means sets the motor rotation speed Nm to the second motor rotation speed threshold Nm.TH2 (NmTH2> NmTH1) In the present embodiment, 125 [rpm] or more and the absolute value | Tn | is 20 [%] or more of the maximum torque, and the fourth required torque threshold TnTH4 (TnTH2> TnTH4> TnTH1) In the present embodiment, it is determined whether it belongs to the area AR5 smaller than 40 [%]. When the motor rotation speed Nm and the absolute value | Tn | belong to the area AR5, the heat dissipation amount calculation processing means sets the heat dissipation amount R to a value q.
[0068]
When the motor rotation speed Nm and the absolute value | Tn | do not belong to the areas AR4 and AR5, the heat dissipation amount calculation processing means sets the motor rotation speed Nm to the third motor rotation speed threshold Nm.TH3 (NmTH3> NmTH2) In the present embodiment, it is 250 [rpm] or more, the absolute value | Tn | is 40 [%] or more of the maximum torque, and the fifth required torque threshold TnTH5 (TnTH2> TnTH5> TnTH4) In the present embodiment, it is determined whether or not the area AR6 is smaller than 60%. When the motor rotation speed Nm and the absolute value | Tn | belong to the area AR6, the heat dissipation amount calculation processing means sets the heat dissipation amount R to a value q.
[0069]
Further, the heat dissipation amount calculation processing means sets the heat dissipation amount R to zero when the motor rotation speed Nm and the absolute value | Tn | do not belong to the areas AR4 to AR6.
[0070]
Thus, in the heat dissipation amount calculation process, when the absolute value | Tn | is 20% or less of the maximum torque, the motor rotation speed Nm is 125 [rpm] or more and the absolute value | Tn | When the torque is 20% or more and smaller than 40%, the motor rotation speed Nm is 250 rpm or more, and the absolute value | Tn | is 40% or more of the maximum torque. On the other hand, if it is smaller than 60 [%], the heat radiation amount R is assumed to be a value q, and otherwise, the heat radiation amount R is assumed to be zero.
[0071]
Next, a flowchart will be described.
Step S2-4-1: It is determined whether or not the absolute value | Tn | is 20% or less of the maximum torque. If the absolute value | Tn | is less than 20% of the maximum torque, the process proceeds to step S2-4-2. If the absolute value | Tn | is greater than 20% of the maximum torque, the process proceeds to step S2-4-3. move on.
Step S2-4-2: Set the value q to the heat radiation amount R and return.
Step S2-4-3 It is determined whether or not the motor rotational speed Nm is 125 [rpm] or more and the absolute value | Tn | is 20 [%] or more of the maximum torque and smaller than 40 [%]. If the motor rotation speed Nm is 125 [rpm] or more and the absolute value | Tn | is 20 [%] or more of the maximum torque and less than 40 [%], the motor rotation speed is determined in step S2-4-2. Is smaller than 125 [rpm], and the absolute value | Tn | is 40% or more of the maximum torque or smaller than 20%, the process proceeds to step S2-4-4.
Step S2-4-4: It is determined whether or not the motor rotational speed Nm is 250 [rpm] or more and the absolute value | Tn | is 40 [%] or more of the maximum torque and is smaller than 60 [%]. When the motor rotation speed Nm is 250 [rpm] or more and the absolute value | Tn | is 40 [%] or more of the maximum torque and smaller than 60 [%], the motor rotation speed is determined in Step S2-4-2. Is smaller than 250 [rpm] and the absolute value | Tn | is 60% or more of the maximum torque or smaller than 40%, the process proceeds to step S2-4-5.
Step S2-4-5: Zero is set for the heat radiation amount R, and the process returns.
[0072]
Next, the subroutine of the offset temperature calculation process in step S2-5 in FIG. 5 will be described.
[0073]
In this case, the DC voltage VCThe offset temperature to is preset with respect to the DC voltage V in the memory.CAnd the offset temperature to are associated with each other and recorded as a table.
[0074]
Since the capacitor 20 is disposed between the main relay 15 and the inverter 40 as described above, the driving of the electric vehicle is terminated and the driver turns off an ignition key (not shown). When the battery 14 and the capacitor 20 are disconnected, the discharge starts, and the amount of charge decreases with time, and the DC voltage VCBecomes lower. That is, the DC voltage VCRepresents the state of the inverter 40 when the ignition key is turned on.
[0075]
Further, as the driver turns off the ignition key, the transistors Tr1 to Tr6 are turned off and no longer generates heat, the inverter 40 naturally releases heat, and the temperature of the inverter 40 gradually increases. Lower.
[0076]
Therefore, when the driver turns off the ignition key and then turns it on again, the DC voltage V is used instead of measuring the time from turning off to turning on.CThe longer the time from turning off to turning on, that is, the DC voltage VCThe lower the temperature is, the lower the offset temperature to is. Therefore, when the driver turns on the ignition key after turning it off, the estimated temperature te can be accurately calculated. Further, the DC voltage V is calculated in order to calculate the offset temperature to.CTherefore, it is not necessary to provide a special sensor. Therefore, the cost of the motor drive device 10 can be reduced.
[0077]
Therefore, the offset temperature calculation processing means determines whether or not the ignition key is turned on, and when the ignition key is turned on, the DC voltage VCIs read and the offset temperature to is calculated. In this case, the offset temperature calculation processing means is a DC voltage VCIs the first DC voltage threshold VC TH1. In the present embodiment, it is determined whether the voltage is 30 [V] or more, and the DC voltage VCIs 30 [V] or higher, the offset temperature to is set to a value to1 (for example, 30 [° C.]). Further, the offset temperature calculation processing means is configured to supply a DC voltage VCIs lower than 30 [V], the second DC voltage threshold VC TH2. In this embodiment, it is determined whether the voltage is 10 [V] or more, and the DC voltage VCIs lower than 30 [V] and 10 [V] or more, the offset temperature to is set to the value to2 (to2 <to1: for example, 20 [° C.]). The offset temperature calculation processing means is a DC voltage VCIs smaller than 10 [V], the offset temperature to is set to the value to3 (to3 <to2: for example, 10 [° C.]).
[0078]
Thus, when the offset temperature to is set, the offset temperature calculation processing means turns on the main relay 15.
[0079]
Next, a flowchart will be described.
Step S2-5-1: It is determined whether or not the ignition key is turned on. If the ignition key is turned on, the process proceeds to step S2-5-2. If the ignition key is not turned on, the process returns.
Step S2-5-2 DC voltage VCIs read.
Step S2-5-3 DC voltage VCIs determined to be 30 V or more. DC voltage VCIs 30 [V] or more, the DC voltage V is set in step S2-5-4.CIf is smaller than 30 [V], the process proceeds to step S2-5-5.
Step S2-5-4: The value to1 is set to the offset temperature to.
Step S2-5-5 DC voltage VCIs determined to be 10 [V] or more. DC voltage VCIs 10 [V] or more, the DC voltage V is set in step S2-5-6.CIf is smaller than 10 [V], the process proceeds to step S2-5-7.
Step S2-5-6: The value to2 is set to the offset temperature to.
Step S2-5-7: The value to3 is set to the offset temperature to.
Step S2-5-8: Turn on the main relay 15 and return.
[0080]
Next, a subroutine for the stall determination process in step S3 in FIG. 4 will be described.
[0081]
First, the stall determination processing means 94 waits for the stall condition to be satisfied. For this purpose, the stall determination processing means 94 has a first condition that the motor rotational speed Nm is zero, and a sixth required torque threshold value Tn in which an absolute value | Tn | is preset.TH6 (in this embodiment, when the absolute value | Tn | is greater than 50% of the maximum torque) as the second condition, both the first and second conditions are satisfied (Nm = 0 and | Tn |> TnTHIt is determined that the stall condition is satisfied in 6). When at least one of the first and second conditions is not satisfied (Nm ≠ 0 or | Tn | ≦ TnTHIt is determined that the stall condition is not satisfied in 6).
[0082]
When the stall condition is satisfied, the continuous stall time calculation processing means of the stall determination processing means 94 calculates the time when the stall condition is satisfied, that is, the continuous stall time, and records it in a buffer (not shown). Therefore, when the stall condition is satisfied, the continuous stall time calculation processing means starts counting by a timer (not shown), and measures time while the stall condition is satisfied. Then, the cumulative stall time calculation processing means of the stall determination processing means 94 determines whether or not the cumulative value of the continuous stall time recorded in the buffer, that is, whether the cumulative stall time is longer than 3 [seconds]. The continuous stall time constitutes a state value indicating that the inverter 40 is in a stalled state, and the continuous stall time calculation processing means constitutes a state value calculation processing means 91.
[0083]
In FIG. 12, L1 is a line representing the absolute value | Tn |, and L2 is a line representing the first torque limit value ρ1. Then, as shown in FIG. 12, the time τ1 to τ3 in which the absolute value | Tn | is larger than 50% of the maximum torque is the continuous stall time, and the sum of the times τ1 to τ3 is the cumulative stall time. Therefore, the stall determination process determines whether the sum of the times τ1 to τ3 is longer than 3 [seconds].
[0084]
Then, if the accumulated stall time is longer than 3 [seconds], the stall determination processing means 94 determines that a stall state has occurred in the inverter 40 and performs a stall determination.
[0085]
Next, a flowchart will be described.
Step S3-1 Wait until the stall condition is satisfied.
Step S3-2: It is determined whether or not the accumulated stall time is longer than 3 [seconds]. If the accumulated stall time is longer than 3 [seconds], the process proceeds to step S3-3, and if the accumulated stall time is 3 [seconds] or less, the process returns.
Step S3-3: Stall is determined and the process returns.
[0086]
Next, a subroutine for limit torque calculation processing in step S4 in FIG. 4 will be described.
[0087]
In this case, as the first abnormality determination method, the limit torque calculation processing unit 92 determines whether or not the stall determination is performed in the stall determination process. When the stall determination is performed, the first torque limit value is determined. ρ1 is set to 100 to β [%] of the maximum torque. For example, as shown in FIG. 12, when the accumulated stall time becomes longer than 3 [seconds] at the timing t1, the limit torque calculation processing unit 92 passes a predetermined time, for example, 1.5 [seconds] from the timing t1. At the timing t2, the first torque limit value ρ1 is gradually reduced so that the absolute value | Tn | becomes 50% of the maximum torque. Then, the limit torque calculation processing means 92 determines whether or not the motor rotation speed Nm is zero at the timing t2, and if the motor rotation speed Nm is not zero, that is, if the rotor is rotating, the first torque The limit value ρ1 is maintained. When the motor rotation speed Nm is zero at the timing t2, the limit torque calculation processing unit 92 further reduces the first torque limit value ρ1.
[0088]
When the motor rotational speed Nm becomes zero at the timing t3 while the first torque limit value ρ1 is maintained, the limit torque calculation processing unit 92 performs a predetermined time from the timing t3, for example, 1. At the timing t5 when 5 [seconds] have elapsed, the first torque limit value ρ1 is gradually reduced so that the absolute value | Tn | becomes 0 [%] of the maximum torque. In addition, when the motor rotation speed Nm is not zero between the timings t3 and t5, the first torque limit value ρ1 is maintained.
[0089]
Further, when the motor rotational speed Nm becomes zero at the timing t6 while maintaining the first torque limit value ρ1, the limit torque calculation processing unit 92 gradually increases the first torque limit value ρ1. Make it smaller. At time t7, when the absolute value | Tn | becomes 20% of the maximum torque, the first torque limit value ρ1 is gradually increased.
[0090]
Further, when the stall determination process is not performed in the stall determination process, the limit torque calculation processing unit 92 sets the first torque limit value ρ1 to 100% of the maximum torque.
[0091]
Next, the limit torque calculation processing means 92 determines whether or not the estimated temperature te calculated in the estimated temperature calculation process is 60 [° C.] or more as a second abnormality determination method. When the temperature is equal to or higher than [° C.], as shown in FIG. 13, the second torque limit value ρ2 is set to 80% of the maximum torque, and when the estimated temperature te is lower than 60 ° C., the second torque limit The value ρ2 is set to 100% of the maximum torque.
[0092]
Subsequently, the limit torque calculation processing means 92 determines whether or not the actual temperature is 60 [° C.] or higher as a third abnormality determination method. The torque limit value ρ3 is set to γ [%] of the maximum torque corresponding to the actual temperature, and when the actual temperature is lower than 60 [° C.], the third torque limit value ρ3 is set to 100 [%] of the maximum torque. As shown in FIG. 14, the value of γ is changed in correspondence with the actual temperature changing from 60 to 80 ° C., and the third torque limit value as it becomes higher than 60 ° C. ρ3 is reduced. When the actual temperature reaches 80 [° C.], the third torque limit value ρ3 is set to zero, and an alarm is generated by an alarm device (not shown).
[0093]
In this way, when the first to third torque limit values ρ1 to ρ3 are calculated by the first to third abnormality determination methods, the limit torque calculation processing unit 92 performs the first to third torque limit values. The minimum value among the values ρ1 to ρ3 is calculated as the limit torque.
[0094]
When the required torque Tn is larger than the limit torque, the torque command value calculation processing means calculates the limit torque as a torque command value, and the current command value calculation processing means 96 calculates the d-axis current command value i.dsAnd q-axis current command value iqsIs calculated and sent to the motor control unit 45. As a result, when the first torque limit value ρ1 is calculated as the limit torque, the motor control unit 45 performs stall control, and when the second torque limit value ρ2 is calculated as the limit torque, the motor control unit 45 When the estimated temperature control is performed and the third torque limit value ρ3 is calculated as the limit torque, the motor control unit 45 performs the actual temperature control.
[0095]
Next, a flowchart will be described.
Step S4-1: It is determined whether or not the stall determination has been performed. If the stall determination is made, the process proceeds to step S4-2. If not, the process proceeds to step S4-3.
Step S4-2: 100 to β [%] of the maximum torque is set to the first torque limit value ρ1.
Step S4-3: Set 100% of the maximum torque to the first torque limit value ρ1.
Step S4-4: It is determined whether the estimated temperature te is 60 [° C.] or higher. When the estimated temperature te is 60 [° C.] or higher, the process proceeds to step S4-5, and when the estimated temperature te is lower than 60 [° C.], the process proceeds to step S4-6.
Step S4-5: 80% of the maximum torque is set to the second torque limit value ρ2.
Step S4-6: Set 100% of the maximum torque to the second torque limit value ρ2.
Step S4-7: It is determined whether the actual temperature is 60 [° C.] or higher. If the actual temperature is 60 [° C.] or higher, the process proceeds to step S4-8. If the actual temperature is lower than 60 [° C.], the process proceeds to step S4-9.
Step S4-8 The maximum torque γ [%] is set to the third torque limit value ρ3.
Step S4-9: Set 100% of the maximum torque to the third torque limit value ρ3.
Step S4-10 The minimum value of the first to third torque limit values ρ1 to ρ3 is set as the limit torque, and the process returns.
[0096]
By the way, if the minimum value among the first to third torque limit values ρ1 to ρ3 is calculated as the limit torque, the first to third ranges are calculated for each region of the motor rotation speed / required torque when the motor 31 is driven. The abnormality determination method can be set, and the torque limit can be reduced based on the first to third torque limit values ρ1 to ρ3.
[0097]
FIG. 15 is a second diagram for explaining regions of motor rotation speed and required torque in the embodiment of the present invention. In the figure, the horizontal axis represents the motor rotation speed Nm, and the vertical axis represents the required torque Tn.
[0098]
For example, if the motor rotation speed Nm is the first motor rotation speed threshold NmTH1. In the present embodiment, the absolute value | Tn | is lower than 20 [rpm] and the second required torque threshold TnTH2. In the present embodiment, when the maximum torque is 80% or more of the maximum torque, the motor rotation speed Nm and the absolute value | Tn | belong to the area AR11. In this case, in the limit torque calculation process, the first torque limit value ρ1 is minimized, the first torque limit value ρ1 is calculated as the limit torque, and stall control is performed in the motor control unit 45 (FIG. 2). .
[0099]
Therefore, when the required torque Tn is large, such as when starting, traveling uphill, or during rapid acceleration, the temperature of each of the transistors Tr1 to Tr6 increases rapidly, and the temperature of the inverter 40 also increases rapidly. In this case, the abnormality of the inverter 40 can be quickly detected by the stall determination. As a result, the limit torque can be quickly reduced and the temperature of the inverter 40 can be lowered.
[0100]
Further, the motor rotation speed Nm is equal to the first motor rotation speed threshold Nm.TH1. In this embodiment, 20 [rpm] or more and the absolute value | Tn | is the second required torque threshold value Tn.TH2. In the present embodiment, when the maximum torque is 80% or more of the maximum torque, the motor rotational speed Nm and the absolute value | Tn | belong to the area AR12. In this case, in the limit torque calculation process, the second torque limit value ρ2 is minimized, the second torque limit value ρ2 is calculated as the limit torque, and the motor controller 45 performs the estimated temperature control.
[0101]
Accordingly, when the temperature of the predetermined transistor is increased and the temperature of the inverter 40 is locally increased, even if the temperature sensor 22 is disposed at a position away from the predetermined transistor, the estimated temperature te is obtained. Based on this, the abnormality of the inverter 40 can be reliably detected. As a result, the torque limit can be reliably reduced and the temperature of the inverter 40 can be lowered.
[0102]
The absolute value | Tn | is the second required torque threshold value Tn.TH2. In the present embodiment, when the maximum torque is smaller than 80%, the motor rotation speed Nm and the absolute value | Tn | belong to the area AR13. In this case, in the limit torque calculation process, the third torque limit value ρ3 is minimized, the third torque limit value ρ3 is calculated as the limit torque, and the motor controller 45 performs actual temperature control.
[0103]
Therefore, even if the amount of heat radiation of the transistors Tr1 to Tr6 varies depending on the mounting state of the transistors Tr1 to Tr6, the abnormality of the inverter 40 can be reliably detected based on the actual temperature. As a result, the torque limit can be reliably reduced and the temperature of the transistors Tr1 to Tr6 can be lowered.
[0104]
In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.
[0105]
【The invention's effect】
  As described above in detail, according to the present invention, in the motor drive device, the current supplied from the power source is converted into the phase current in accordance with the switching of the power source, the motor, and the switching element, and the motor. An inverter to be supplied to the inverter, an inverter temperature detecting means that is disposed at a predetermined location in the inverter and detects a local temperature at the predetermined location as an actual temperature of the inverter, an actual temperature detected at a predetermined timing, And an estimated temperature calculation processing means for calculating an estimated temperature representing the entire temperature of the inverter based on a temperature correction value for correcting the actual temperature corresponding to the state of the inverter, and that the inverter is in a stalled state. Continuous stall time calculation processing means for calculating a continuous stall time to be expressed, and a first torque limit based on the continuous stall time The second torque limit value is calculated based on the estimated temperature, the third torque limit value is calculated based on the actual temperature, and the minimum value among the first to third torque limit values is calculated as the limit torque. Limiting torque calculation processing means.
[0106]
  In this case, the limit torque is calculated based on one of the actual temperature, estimated temperature, and continuous stall time, so if the required torque is large, such as when starting, climbing, or sudden acceleration, each switching Although the temperature of the element is rapidly increased and the temperature of the inverter is also rapidly increased, an abnormality of the inverter can be quickly detected based on the estimated temperature and the continuous stall time. Therefore, the torque limit can be quickly reduced and the inverter temperature can be lowered.
[0107]
  Further, when the temperature of the predetermined switching element becomes high and the temperature of the inverter becomes locally high, even if the inverter temperature detecting means is disposed at a position away from the predetermined switching element, the estimated temperature Based on the above, it is possible to reliably detect the abnormality of the inverter. Therefore, the torque limit can be reliably reduced and the inverter temperature can be lowered.
[0108]
Further, even if the heat dissipation amount of each switching element varies depending on the mounting state of the switching element, it is possible to reliably detect an abnormality of the inverter based on the actual temperature. Therefore, the torque limit can be reliably reduced and the inverter temperature can be lowered.
[Brief description of the drawings]
FIG. 1 is a functional block diagram of a motor drive device according to an embodiment of the present invention.
FIG. 2 is a conceptual diagram of a motor drive device according to an embodiment of the present invention.
FIG. 3 is a block diagram of a motor control unit in the embodiment of the present invention.
FIG. 4 is a main flowchart showing the operation of the motor drive device in the embodiment of the present invention.
FIG. 5 is a diagram showing a subroutine of estimated temperature calculation processing in the embodiment of the present invention.
FIG. 6 is a diagram showing a subroutine of estimated temperature coefficient calculation processing in the embodiment of the present invention.
FIG. 7 is a diagram showing a subroutine of heat release amount calculation processing in the embodiment of the present invention.
FIG. 8 is a diagram showing a subroutine of offset temperature calculation processing in the embodiment of the present invention.
FIG. 9 is a first diagram illustrating regions of motor rotation speed / required torque in the embodiment of the present invention.
FIG. 10 is a diagram showing a subroutine of stall determination processing in the embodiment of the present invention.
FIG. 11 is a diagram showing a subroutine of limit torque calculation processing in the embodiment of the present invention.
FIG. 12 is a time chart showing an operation of a stall determination process in the embodiment of the present invention.
FIG. 13 is a diagram showing a relationship between a second torque limit value and an estimated temperature in the embodiment of the present invention.
FIG. 14 is a diagram showing a relationship between a third torque limit value and an actual temperature in the embodiment of the present invention.
FIG. 15 is a second diagram illustrating a region of motor rotation speed / required torque in the embodiment of the present invention.
[Explanation of symbols]
10 Motor drive device
14 battery
17 Vehicle control circuit
22 Temperature sensor
31 motor
40 inverter
91 State value calculation processing means
92 Limiting torque calculation processing means
93 Estimated temperature calculation processing means
IU, IV, IW    Current
Tr1 to Tr6 transistors

Claims (3)

  1. In accordance with switching of the power source, the motor, and the switching element, the current supplied from the power source is converted into a phase current and supplied to the motor, and the inverter is disposed at a predetermined location in the inverter . Inverter temperature detection means for detecting the local temperature at the location as the actual temperature of the inverter , the actual temperature detected at a predetermined timing, and a temperature correction value for correcting the actual temperature according to the state of the inverter Based on the estimated temperature calculation processing means for calculating the estimated temperature representing the overall temperature of the inverter, the continuous stall time calculation processing means for calculating the continuous stall time indicating that the inverter is in the stalled state, and the continuous stall time. Based on the first torque limit value based on the estimated temperature, based on the second torque limit value based on the estimated temperature, Calculating a third torque limit value, the motor driving apparatus characterized by having a limit torque calculation processing means for calculating a minimum value among the first to third torque limit value as a limit torque.
  2.   The temperature correction value is an integrated value representing an offset temperature due to heat held in the inverter when the actual temperature is detected and a heat balance of the inverter from when the actual temperature is detected to the present. The motor drive device described.
  3. With the switching of the switching elements constituting the inverter, and supplied to the motor by converting a current supplied from a power source to the phase current, detecting a local temperature at a given point of the inverter as the actual temperature of the inverter, a predetermined Based on the actual temperature detected at the timing and the temperature correction value for correcting the actual temperature corresponding to the inverter state, an estimated temperature representing the entire temperature of the inverter is calculated, and the inverter enters the stalled state. Calculating a continuous stall time indicating that there is a first torque limit value based on the continuous stall time, a second torque limit value based on the estimated temperature, and a third torque based on the actual temperature. A motor driving method characterized by calculating a limit value and calculating a minimum value among the first to third torque limit values as a limit torque.
JP2000232003A 2000-07-31 2000-07-31 Motor driving apparatus and motor driving method Expired - Fee Related JP4304842B2 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4513276B2 (en) * 2003-05-22 2010-07-28 トヨタ自動車株式会社 Power output device, its control method, and automobile
JP4055003B2 (en) 2003-09-04 2008-03-05 アイシン・エィ・ダブリュ株式会社 Control device for motor for driving vehicle
KR100747228B1 (en) * 2006-04-28 2007-08-01 현대자동차주식회사 A method for protect inverter power device from overheating when a motor stalled
JP4862512B2 (en) * 2006-06-22 2012-01-25 日産自動車株式会社 Motor output control device for electric vehicle
JP4830927B2 (en) * 2007-03-15 2011-12-07 トヨタ自動車株式会社 Electric vehicle with inverter overheat warning device
JP5434066B2 (en) * 2008-12-18 2014-03-05 日産自動車株式会社 Control device for hybrid vehicle
GB2463130B (en) * 2009-07-29 2011-06-22 Protean Holdings Corp Torque control system
JP5733140B2 (en) * 2011-09-29 2015-06-10 トヨタ自動車株式会社 Electric vehicle
JP5790397B2 (en) * 2011-10-18 2015-10-07 トヨタ自動車株式会社 electric vehicle
JP5919012B2 (en) * 2012-02-08 2016-05-18 本田技研工業株式会社 Control device for motor for driving vehicle
JP6274077B2 (en) * 2014-11-04 2018-02-07 株式会社デンソー Motor control device

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