JP6421598B2 - Motor control device and control method - Google Patents

Description

  The present invention relates to a motor control device and a control method.

A voltage phase control by an inverter is known as a method for controlling the driving torque of an electric motor serving as a driving force source for an electric vehicle or the like. In Patent Document 1, when the rotational speed of the electric motor changes suddenly due to sudden deceleration of the electric vehicle, the voltage amplitude applied to the electric motor is decreased according to the deceleration, and the amount of current applied to the electric motor increases. A control device for suppressing the above is disclosed.
Japanese Patent No. 4706324

  When the voltage amplitude is decreased according to the deceleration as in the above-described conventional technique, there is a characteristic that more weak flux current flows when the voltage is decreased, particularly in the weak flux region. In some cases, the effect of suppressing the reduction is lost.

  In addition, the current can be controlled to decrease the amount of current by directly operating the voltage amplitude, but the current may increase due to sudden deceleration even in the current vector control mode, and the current is suppressed in the current vector control mode. The effect of doing will fade.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an electric motor control apparatus that can suppress an increase in current during sudden deceleration.

  One embodiment of the present invention is applied to an electric motor drive device that calculates an electric motor drive torque command value in accordance with a torque command and drives the electric motor. According to the motor drive device, a torque upper limit calculation processing unit that calculates a torque upper limit value of the motor according to a rotation speed of the motor, a drive torque command value of the motor based on the torque upper limit value and the torque instruction. A torque command value limiting unit to calculate; and an electric motor control unit that outputs electric power for driving the electric motor to the electric motor based on the calculated drive torque command value. The torque command value limiter calculates a delayed torque upper limit value obtained by delaying the torque upper limit value with a predetermined response, compares the torque upper limit value with the calculated delayed torque upper limit value, and as a result of comparison, whichever is smaller The torque command value is limited by this value.

  According to the present invention, as a result of the comparison between the torque upper limit value and the calculated delay torque upper limit value, the torque command value is limited by the smaller value. For example, during sudden acceleration in the high torque region or sudden When the time change rate of the torque of the motor becomes steep, such as during deceleration, the torque command value is limited by the delay torque upper limit value. Thereby, it can control so that the torque command value of an electric motor may not change suddenly, and the electric current increase of the electric motor at the time of sudden acceleration and sudden deceleration can be suppressed.

It is explanatory drawing of the control apparatus of the electric motor of 1st Embodiment of this invention. It is a block diagram of the configuration of the torque upper limit calculation processing unit of the first embodiment of the present invention. It is a block diagram of the configuration of the torque control unit of the first embodiment of the present invention. It is a block diagram of the configuration of the current vector control unit of the first embodiment of the present invention. It is a block diagram of the voltage phase control unit of the first embodiment of the present invention. It is explanatory drawing of the table which shows the torque upper limit of 1st Embodiment of this invention. It is explanatory drawing which shows the relationship between the motor terminal voltage and the rotation speed detected value N in the conventional current vector control. It is explanatory drawing which shows the relationship between the voltage phase in the conventional voltage phase control, and the rotation speed detected value N. It is explanatory drawing of the upper limit at the time of rapid deceleration of 1st Embodiment of this invention. It is explanatory drawing of the upper limit at the time of the rapid acceleration of 1st Embodiment of this invention. It is explanatory drawing of the torque upper limit calculation process part of 2nd Embodiment of this invention. It is explanatory drawing which shows the example of the torque upper limit table of 2nd Embodiment of this invention. It is explanatory drawing which shows switching of the torque upper limit of 2nd Embodiment of this invention. It is explanatory drawing of the torque upper limit calculation process part of 3rd Embodiment of this invention. It is explanatory drawing of the weighting table of 3rd Embodiment of this invention. It is explanatory drawing of the control apparatus of the electric motor of 4th Embodiment of this invention. It is explanatory drawing of the torque upper limit calculation process part of 4th Embodiment of this invention. It is explanatory drawing of the torque upper limit calculation process part of 5th Embodiment of this invention. It is explanatory drawing of the weighting table of 5th Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment>
FIG. 1 is an explanatory diagram of a motor control device 100 according to the first embodiment of the present invention.

The motor control device 100 is mounted on an electric vehicle, for example, and controls the driving torque of the electric vehicle based on a driver's instruction. The torque control unit 3 performs current vector control or voltage phase control based on the torque command T ^* , thereby controlling the output of the three-phase power of the inverter 6 to control the drive torque of the electric motor (motor) 9.

The torque upper limit calculation processing unit 1 calculates a torque upper limit value T _{lim +} and a torque lower limit value T _lim− of the driving torque of the motor 9 and outputs them to the torque command value limit processing unit 2 as will be described later.

The torque command value limit processing unit 2 is based on the command torque T ^* instructed by the driver and the torque upper value T _{lim +} and the torque lower limit value T _lim− output from the torque upper value calculation processing unit 1. T ^* _fin is calculated and output to the torque control unit 3.

The torque control unit 3 determines the d-axis voltage command value based on the torque command value T ^* _fin , the battery voltage detection value V _dc , the rotation speed detection value N, the d-axis current value i _d , and the q-axis current i _q. v ^* _d and q-axis voltage command value v ^* _q are calculated and output to the dq-axis-UVW phase converter 4.

The dq axis-UVW phase conversion unit 4 converts the d axis voltage command value v ^* _d and the q axis voltage command value v ^* _q into UVW phase voltage command values v ^* _u , v ^* _v , v ^* _w, and outputs PWM Output to the conversion unit 5.

The PWM converter 5 determines the command values (D ^* _uu , D ^* _ul , D ^* _vu , D ^* _vl , D ^{*) of the} inverter 6 based on the UVW phase voltage command values v ^* _u , v ^* _v , v ^* _w ^. _wu , D ^* _wl ) are output.

  The inverter 6 converts the DC power of the battery 7 into three-phase AC power based on the command value output from the PWM conversion unit 5 and outputs it to the motor 9.

The output of the inverter 6 provided with a current detector 8 detects at least two phases of the current values i _u, i _v of the three-phase power. The motor 9 is provided with a rotor position sensor 10 and detects an electrical angle detection value θ of the motor 9.

The detected current values i _u and _iv and the electrical angle detection value θ are input to the UVW phase-dq axis converter 12. UVW phase -dq axis conversion unit 12 converts the input value current value i _d of the dq axes, the i _q, and outputs it to the torque controller 3.

  The electrical angle detection value θ output from the rotor position sensor 10 is converted into a rotation speed detection value N of the motor 9 by the rotation speed calculation unit 11 and input to the torque control unit 3.

  FIG. 2 is a configuration block diagram of the torque upper limit calculation processing unit 1 according to the embodiment of the present invention.

  The torque upper value calculation processing unit 1 includes a positive torque upper value table 101, a negative torque upper value table 102, low pass filters (LPF) 103 and 104, a select Lo unit 105, and a select Hi unit 106.

The torque upper value calculation processing unit 1 stores a positive torque upper value table 101 and a negative torque upper value table 102 in advance. The torque upper limit calculation processing unit 1 uses the positive torque upper limit value table 101 and the negative torque upper limit value table 102 based on the input rotation speed detection value N and the battery voltage V _dc, and thereby determines the positive torque upper limit value T. _{lim1 +} and negative torque upper limit value _Tlim1- are calculated.

The calculated positive torque upper limit value T _{lim1 +} and negative torque upper limit value T _lim1- are subjected to low-pass filter processing by the LPFs ₁₀₃ and ₁₀₄ , respectively. By the low-pass filter processing, a positive-side lag torque upper limit value T _{lim1fit +} and a negative-side lag torque upper limit value T _lim1fit− each having a predetermined response delay are generated.

The selection Lo unit 105 compares the positive torque upper limit value T _{lim +} calculated from the table with the positive delay torque upper limit value T _{lim1fit +} subjected to the low-pass filter process. As a result of the comparison, the smaller one (the smaller absolute value) of the positive torque upper limit value T _{lim +} and the positive delay torque upper limit value T _{lim1fit +} is selected. The selected value is output to the torque command value limit processing unit 2 as the positive torque upper limit value T _{lim +} .

The selection Hi unit 106 compares the negative side torque upper limit value T _lim− calculated from the table with the negative side delayed torque upper limit value T _lim1fit− subjected to the low pass filter process. As a result of comparison, the larger one (the smaller absolute value) of the negative torque upper limit value T _lim− and the negative delay torque upper limit value T _lim1fit− is selected. The selected value is output to the torque command value limit processing unit 2 as the negative torque upper limit value T _lim− .

The torque command value limit processing unit 2 executes a process of limiting the torque command value T ^* to a range between the positive side torque upper limit value T _{lim +} and the negative side torque upper limit value T _lim− based on the following formula 1. To do. As a result of this processing, the torque command value limit processing unit 2 outputs the final torque command value T ^* _fin to the torque control unit 3.

  FIG. 3 is a block diagram showing the configuration of the torque control unit 3 according to the embodiment of the present invention.

  The torque control unit 3 includes a current vector control unit 31, a voltage phase control unit 32, a control switching determination unit 33, and a control mode switching unit 34.

The torque control unit 3 selects current vector control or voltage phase control based on the input final torque command value T ^* _fin , rotation speed detection value N, and battery voltage V _dc , and the current vector control unit 31 or voltage phase The dq axis voltage command values v ^* _d and v ^* _q calculated by the control unit 32 are output.

  FIG. 4 is a configuration block diagram of the current vector control unit 31. In FIG. 4, only the configuration on the d-axis side is shown, but the configuration is omitted because it is the same on the q-axis side.

  The current vector control unit 31 includes a non-interference voltage calculation unit 311, a current command value calculation unit 312, a filter processing unit 313, and a PI amplification unit 314.

The non-interference voltage calculation unit 311 stores in advance a table in which the final torque command value T ^* _fin , the rotation speed detection value N, the battery voltage V _dc, and the non-interference voltage value are associated with each other. Similarly, the current command value calculation unit 312 stores in advance a table in which the final torque command value T ^* _fin , the rotation speed detection value N, the battery voltage V _dc, and the current command value are associated with each other.

The non-interference voltage calculation unit 311 and the current command value calculation unit 312 perform a lookup process on the table based on the input final torque command value T ^* _fin , the battery voltage detection value _Vdc, and the rotation speed detection value N. The d-axis non-interference voltage value v ^* _{d_dcpl} and the d-axis current command value i ^* _d are calculated.

The d-axis current command value i ^* _d calculated by the current command value calculation unit 312 is determined by the PI amplification unit 314 from the difference from the detected current value i _d in the d-axis input from the UVW phase-dq axis conversion unit 12. Then, the PI amplified value v ′ _di is calculated by the following formula 2.

The d-axis non-interference voltage value v ^* _{d_dcpl} calculated by the non-interference voltage calculation unit 311 is subjected to filter processing equivalent to the current reference response in the filter processing unit 313 to calculate the d-axis non-interference voltage value v ^* _{d_dcpl_filt} .

The current vector control unit 31 calculates the voltage command value v ^* _di by adding the calculated value v ′ _di and the d-axis non-interference voltage value v ^* _{d_dcpl_filt according} to the following Equation 3.

  FIG. 5 is a configuration block diagram of the voltage phase control unit 32.

  The voltage phase control unit 32 includes a voltage command value calculation unit 321, a vector conversion unit 322, a filter processing unit 323, a PI amplification unit 324, and a torque estimation unit 325.

The voltage command value calculation unit 321 stores in advance a table in which the final torque command value T ^* _fin , the rotation speed detection value N, the battery voltage _Vdc, and the voltage amplitude and voltage phase are associated with each other. The voltage command value calculation unit 321 performs a look-up process on the table based on the input final torque command value T ^* _fin , battery voltage detection value _Vdc, and rotation speed detection value N, so that the voltage amplitude command value V ^* _a And the voltage phase command value α ^* _ff is calculated.

The filter processing unit 323 calculates the reference torque T _ref by performing filter processing of desired response characteristics on the final torque command value T ^* _fin according to the following mathematical formula 4.

The torque estimation unit 325 calculates the estimated torque T _cal from the dq axis current detection values id and iq input from the UVW phase-dq axis conversion unit 12 according to the following Equation 5.

The PI amplification unit calculates a voltage phase correction value α ^* _fb obtained by PI amplification from the difference between the reference torque T _ref and the estimated torque T _{cal according} to the following Equation 6.

The final voltage phase command value α ^* _fin, which is the sum of the calculated voltage phase command value α ^* _ff and the voltage phase correction value α ^* _fb calculated by the voltage command value calculation unit 321, is calculated by the following Equation 7. The voltage amplitude command value V ^* _a is input to the vector conversion unit.

The vector conversion unit 322 converts the input voltage amplitude command value V ^* _a and the final voltage phase command value α ^* _fin into a dq-axis component according to the following formula 8, and dq-axis voltage command value v ^* _dv , Output v ^* _qv .

The dq axis voltage command values v ^* _dv and v ^* _qv output from the torque control unit 3 are calculated by the following equation 9 based on the electrical angle detection value θ of the motor 9 in the dq axis-UVW phase conversion unit 4. Phase voltage command values v ^* _u , v ^* _v , v ^* _w are converted and output.

As shown in FIG. 1, based on the three-phase voltage command values v ^* _u , v ^* _v , and v ^* _w output from the dq axis-UVW phase conversion unit 4, the PWM conversion unit 5 converts the power element of the inverter 6. A drive signal is output.

The inverter 6 applies three-phase voltages v _u , v _v , v _w to the motor 9 based on the power element drive signal, so that the motor 9 generates drive torque.

Power applied to the motor 9, the current value i _u at least two phases of the three phase by the current detection unit 8, i _v is detected. Detected current value i _u, i _v, depending UVW phase -dq axis conversion portion 12, and is converted dq-axis current i _d, the i _q by the following equation 10 based on the electric angle detection value θ of the motor 9 .

Through the control as described above, the driving torque of the motor 9 is controlled based on the torque command T ^* .

  Next, the control at the time of sudden deceleration in the embodiment of the present invention will be described.

  FIG. 6 is an explanatory diagram of a table showing the torque upper limit value in the torque upper limit calculation processing unit 1 of the present embodiment.

The positive torque upper limit value T _{lim +} and the negative torque upper limit value T _lim− are set as shown in the table of FIG. 6 corresponding to the rotation speed detection value N of the motor 9 and the battery voltage detection value V _dc . It is stored in the upper limit calculation processing unit 1 in advance.

  When the rotational speed detection value N of the motor 9 is small or large, the command torque of the motor 9 is regulated by the torque upper limit value. In particular, when the rotation speed detection value N of the motor 9 is large, the current applied to the motor 9 increases, and therefore the torque of the motor 9 is regulated by the torque upper limit value for the purpose of preventing overcurrent. The torque upper limit value is set so as to change gradually as the rotation speed detection value N decreases.

The torque upper limit calculation processing unit 1 holds a torque upper limit table as shown in FIG. 6 in advance, and limits the upper limit value of the command torque T ^* .

  Conventionally, there has been the following problem in the control of the motor control apparatus configured as described above.

  Based on the electrical angle detection value θ detected by the rotor position sensor 10, the rotation speed calculation unit 11 calculates the rotation speed detection value N. At this time, since the rotation speed calculation unit 11 calculates the rotation speed based on the change amount of the electrical angle detection value θ at a certain time interval, the rotation speed detection value N is delayed from the actual rotation speed of the motor 9. Can occur. If the time interval is reduced, the delay is reduced, but a certain time is required for the purpose of eliminating the influence of noise in the rotor position sensor 10, and the delay of the rotation speed detection value N must be allowed.

  7 and 8 are explanatory diagrams for explaining the influence of the delay in the rotation speed detection value N. FIG.

  FIG. 7 is an explanatory diagram showing the relationship between the motor terminal voltage and the rotation speed detection value N in conventional current vector control.

  In FIG. 7, the vertical axis represents the terminal voltage of the motor 9, and the horizontal axis represents the rotation speed detection value of the motor 9. In FIG. 7, the operating point of the motor 9 when the indicated torque is small is plotted as a diamond point, and the operating point of the motor 9 when the indicated torque is large is plotted as a square point.

  In the example shown in FIG. 7, when the command torque is large, the operating point of the motor 9 has a steeper slope in the relationship between the rotation speed detection value N and the terminal voltage than when the command torque is small. Yes. In this case, the rotational speed detection value N (indicated by point A) of the motor 9 at a certain time is delayed from the actual motor rotational speed detection value N (indicated by point B). By this delay, control is performed so that the voltage at point A is applied to the motor 9. Although this delay is corrected by feedback, since correction by feedback processing is not in time for sudden acceleration or sudden deceleration, an overcurrent may be temporarily generated in the motor 9.

  FIG. 8 is an explanatory diagram showing the relationship between the voltage phase and the rotation speed detection value N in the conventional voltage phase control.

  In FIG. 8, the vertical axis represents the voltage phase of the motor 9, and the horizontal axis represents the rotation speed detection value of the motor 9. In FIG. 8, the operating point of the motor 9 when the indicated torque is small is plotted as a diamond point, and the operating point of the motor 9 when the indicated torque is large is plotted as a square point.

  Also in the voltage phase control, when the torque is large, the change in the voltage phase with respect to the change in the rotation speed detection value N is large. Therefore, the rotation speed detection value N (indicated by point A) of the motor 9 at a certain point in time is There is a delay with respect to the motor rotation speed detection value N (indicated by point B). Accordingly, similarly, since the correction by the feedback process is not in time at the time of sudden acceleration or sudden deceleration, there is a possibility that an overcurrent is temporarily generated in the motor 9.

  In the present embodiment, an overcurrent is generated by the difference between the detected value of the rotor position sensor 10 and the actual rotational position of the motor, and is configured to be prevented by the operation of the torque upper limit calculation processing unit 1. .

  FIG. 9 is an explanatory diagram of the upper limit value by the torque upper limit calculation processing unit 1 during sudden deceleration according to the present embodiment.

In FIG. 9, the map shows the positive torque upper limit value T _{lim +} when the deceleration is small (dotted line A) and when the deceleration is large (dotted line B) from the deceleration start point to the deceleration end point. It is an example.

  As described above, the torque upper limit calculation processing unit 1 includes the positive torque upper limit value table 101, the LPF 103, and the select Lo unit 105.

When the deceleration is small, the difference between the positive-side torque upper limit value T _{lim1 +} determined based on the motor rotation speed detection value N and the signal T _{lim1fit +} having a predetermined delay due to the low-pass filter processing of the LPF 103 is small. The value of the positive torque upper limit value T _{lim1 +} shown in FIG. 4 is traced to shift from the deceleration start point to the deceleration end point.

On the other hand, when the deceleration is large, the time change rate of the motor rotation speed detection value N is large, and the delay of the signal T _{lim1fit +} due to the low-pass filter processing of the LPF ₁₀₃ is large. As a result, the difference between the positive torque upper limit value T _{lim1 +} and the signal T _{lim1fit +} having a predetermined delay due to the low pass filter processing of the LPF 103 is increased. The select Lo unit 105 outputs a signal T _{lim1fit +} having a large delay and a small absolute value as T _{lim +} .

As a result, as shown by the dotted line B in FIG. 9, the positive torque upper limit value T _{lim +} is output as a value smaller than the value of the positive torque upper limit value T _{lim1 +} shown in FIG. As a result, when sudden deceleration occurs in a situation where the accelerator opening is fully open, the final torque command value T ^* _fin is limited more than during normal travel.

  FIG. 10 is an explanatory diagram of the upper limit value by the torque upper limit calculation processing unit 1 during sudden acceleration according to the present embodiment.

In FIG. 10, the change in the positive torque upper limit value T _{lim +} from the acceleration start point to the acceleration end point shows transition between when the acceleration is small (dotted line A) and when the acceleration is large (dotted line B).

When the acceleration is small, the difference between the positive torque upper limit value T _{lim1 +} determined based on the motor rotation speed detection value N and the signal T _{lim1fit +} having a predetermined delay due to the low pass filter processing of the LPF 103 is the same as during deceleration. Is traced, and _changes from the acceleration start point to the acceleration end point, following the value of the positive torque upper limit value _{Tlim1 +} shown in FIG.

On the other hand, when the acceleration is large, the time change rate of the motor rotation speed detection value N is large, and the delay of the signal T _{lim1fit +} due to the low-pass filter processing of the LPF ₁₀₃ is large. As a result, the difference between the positive torque upper limit value T _{lim1 +} and the signal T _{lim1fit +} having a predetermined delay due to the low pass filter processing of the LPF 103 is increased. The selection Lo unit 105 outputs the value of the positive torque upper limit value T _{lim1 +} shown in FIG. 6 as T _{lim +} instead of the signal T _{lim1fit +} with a large delay and a small absolute value.

As a result, as shown by the solid line in FIG. 10, the positive torque upper limit value T _{lim +} is output by tracing the value of the positive torque upper limit value T _{lim1 +} shown in FIG. As a result, even during sudden acceleration, the final torque command value T ^* _fin for the actual rotational speed does not exceed the original positive torque upper limit value T _{lim1 +} .

As described above, in the first embodiment of the present invention, the torque upper limit calculation processing unit 1 that calculates the positive torque upper limit T _{lim +} and the negative torque upper limit T _lim− for limiting the command torque T ^*. Are provided with an LPF 103 and an LPF 104, a select Lo unit 105 and a select Hi unit 106. The LPF 103 and the LPF 104 delay the response of the positive side torque upper limit value T _{lim1 +} and the negative side torque upper limit value T _lim1 calculated based on the motor rotation speed detection value N.

Select Lo 105, positive maximum torque T _{lim1 +} values and the signal having a predetermined delay (delay positive torque upper limit value) of the _T lim1fit ₊ value, less any smaller value (absolute value Value). The selection Hi unit 106 selects the larger value (absolute value) _between the value of the negative torque upper limit value T _{lim1 and} the value of the signal having a predetermined delay (delayed negative torque upper limit value) T _lim1fit- Is a small value).

  With such a configuration, even when the time change rate of the torque of the motor 9 becomes steep, such as during sudden acceleration or sudden deceleration in the high torque region, the torque upper limit value calculation processing unit 1 uses the LPF 103 and the LPF 104 to achieve low-pass. The filtered value is calculated. In this way, the torque upper limit value can be controlled so as not to change sharply by the upper limit value to which a predetermined delay has been applied.

Second Embodiment
Next, the control device 100 for the electric motor according to the second embodiment of the present invention will be described.

  In the second embodiment, the configuration of the torque upper limit calculation processing unit 1 is different from that of the first embodiment. Since the other configuration is the same as that of the first embodiment, the same reference numeral is given to the same configuration, and the description thereof is omitted.

  FIG. 11 is an explanatory diagram of the torque upper limit calculation processing unit 1 according to the second embodiment of the present invention.

  In the second embodiment, the torque upper limit calculation processing unit 1 includes a normal positive torque upper limit value table 111, a normal negative torque upper limit value table 112, a second positive torque upper limit value table 121, and a second negative torque upper limit value. A table 122, a rapid deceleration detection unit 131, a switching unit 141, and a switching unit 142 are provided.

The normal positive torque upper limit table 111 and the normal negative torque upper limit table 112 operate in the same manner as the positive torque upper limit table 101 and the negative torque upper limit table 102 of the first embodiment. That is, the normal positive torque upper limit value table 111 and the normal negative torque upper limit value table 112 hold a torque upper limit value table as shown in FIG. 6 in advance, and the input rotational speed detection value N and battery voltage Based on V _dc , a positive torque upper limit value T _{lim1 +} and a negative torque upper limit value T _lim1− are calculated.

The calculated positive maximum torque T _{lim1 +} and the negative maximum torque T _Lim1- and via the switching unit 141 and or the switching unit 142, positive maximum torque T _{lim1 +} and negative maximum torque T _{Lim1- Are} output as T _{lim +} or T _lim− .

Here, when sudden deceleration occurs, the sudden deceleration detector 131 detects the sudden deceleration. The sudden deceleration detection unit 131 suddenly decelerates depending on whether the amount of change per unit time from k−1 to k in the rotational speed of the motor 9 is greater than or less than a predetermined threshold value ΔN _TH as shown in Equation 11. Is output (whether it is Hi or Lo). In the case of sudden deceleration, the switching unit 141 and the switching unit 142 of the torque upper value calculation processing unit 1 replace the normal positive torque upper value table 111 and the normal negative torque upper value table 112 with the second positive torque. A switching signal is transmitted so that the calculation results of the upper limit value table 121 and the second negative torque upper limit value table 122 are output.

The positive torque upper limit value (delayed positive torque upper limit value) T _{lim2 +} held in the second positive torque upper limit value table 121 is the positive torque upper limit value T held in the normal positive torque upper limit value table 111. _An upper limit equivalent to a value delayed by a predetermined response from _{lim1 +} is held. Similarly, the negative torque upper limit value (delayed negative torque upper limit value) T _lim2 held in the second negative torque upper limit table 122 is the negative side held in the normal negative torque upper limit table 112. An upper limit value equivalent to a value delayed by a predetermined response from the torque upper limit value _Tlim1- is held.

The second positive torque upper limit value table 121 or the positive torque upper limit value calculated by the second negative torque upper value table 122 T _{lim2 +} or the negative side torque limit T _Lim2- is, positive torque upper limit value T _{lim +} or negative It is output to the torque command value limit processing unit 2 as the side torque upper limit value T _lim− .

  FIG. 12 is an explanatory diagram illustrating an example of a torque upper limit table in the torque upper limit calculation processing unit 1 according to the second embodiment of the present invention.

  The table shown in FIG. 12 stores a table indicating the second torque upper limit value in addition to the torque upper limit value table in the first embodiment described above with reference to FIG. The second torque upper limit value is set so as to limit the torque so as not to become a high torque in a state where the current applied to the motor is likely to increase, for example, when the vehicle is suddenly decelerated.

  FIG. 13 is an explanatory diagram showing switching of the torque upper limit value in the torque upper limit calculation processing unit 1 in the second embodiment of the present invention.

In FIG. 13, from the deceleration start point to the deceleration end point, the positive torque upper limit T _{lim +} when the deceleration changes from when the deceleration is small (solid line) to when the deceleration is large (dotted line). It is an example of the map which shows a value.

First, deceleration is started at the deceleration start point, and the torque upper limit value is set to the positive torque upper limit value _{Tlim1 +} . Here, when the deceleration increases and the deceleration is judged to be a sudden deceleration by the sudden deceleration detection unit 131, the sudden deceleration detection unit 131 makes a second positive correction to the switching units 141 and 142. A switching signal is sent to output the calculation results of the side torque upper limit value table 121 and the second negative torque upper limit value table 122.

As a result, the positive torque upper limit value T _{lim2 +} calculated by the second positive torque upper limit value table 121 is output to the torque command value limit processing unit 2 as the positive torque upper limit value T _{lim +} .

Thus, in the second embodiment of the present invention, the torque upper limit value calculation processing unit 1 that calculates the positive torque upper limit value T _{lim +} and the negative torque upper limit value T _lim− for limiting the command torque T ^* is: A sudden deceleration detection unit 131 is provided.

The sudden deceleration detection unit 131 detects the sudden deceleration, and the positive torque upper limit value T _{lim1 +} or the negative torque upper limit value T calculated by the positive torque upper limit value table 101 or the negative torque upper limit value table 102. _Instead of _lim1- , the positive torque upper limit value T _{lim2 +} or the negative torque upper limit value T _lim2- calculated by the second positive torque upper limit value table 121 or the second negative torque upper limit value table 122 is output. The switching units 141 and 142 are switched.

As a result, the torque upper limit value T _{lim2 +} and the lower limit torque T _lim2 are selected by the torque upper limit value calculation processing unit 1 during sudden acceleration or sudden deceleration in the high torque region, _thereby selecting the torque upper limit value. Can be suppressed.

  By controlling in this way, the motor 9 is operated in the range of the torque upper limit value that outputs the maximum torque range that can be output by the motor 9 during normal operation, while the torque that can be output by the motor 9 during sudden deceleration. The range can be suppressed to a torque range that prioritizes suppression of overcurrent.

<Third Embodiment>
Next, an electric motor control apparatus 100 according to a third embodiment of the present invention will be described.

  The third embodiment is a modification of the second embodiment, and the configuration of the torque upper limit calculation processing unit 1 is different from that of the first embodiment. Since the other configuration is the same as that of the first embodiment, the same reference numeral is given to the same configuration, and the description thereof is omitted.

  FIG. 14 is an explanatory diagram of the torque upper limit calculation processing unit 1 according to the third embodiment of the present invention.

  In the third embodiment, similarly to the first embodiment, the torque upper limit calculation processing unit 1 includes a normal positive torque upper limit table 111, a normal negative torque upper limit table 112, and a second positive torque upper limit table. 121, a second negative torque upper limit value table 122 is provided.

  In the third embodiment, a positive-side weighting processing unit 151, a negative-side weighting processing unit 152, and an acceleration calculation unit 161 are provided.

The acceleration calculation unit 160 calculates an acceleration equivalent value ΔN _val based on the following formula 12. That is, the acceleration equivalent value ΔN _val is a value indicating the amount of change per unit time from k−1 to k of the rotational speed of the motor 9.

Positive weighting processing unit 151 and negative weighting processing unit 152, based on the acceleration value corresponding .DELTA.N _val the acceleration detecting unit 160 is calculated, as an upper limit value becomes larger when the acceleration of the vehicle is large, performs weighting processing .

  Specifically, the positive-side weighting processing unit 151 holds a weighting table as shown in FIG.

Referring to FIG. 15, the weighting table shows that the positive torque upper limit value T _{lim +} between ΔN _TH1 and ΔN _TH2 is linear between T _{lim1 +} and T _{lim2 +} according to the magnitude of the acceleration equivalent value ΔN _val. It is set to change.

Positive weighting processing unit 151 refers to the weighting table shown in FIG. 15, and obtains the acceleration value corresponding ΔN torque upper limit value corresponding to _val the acceleration detecting unit 160 calculates a (third torque upper limit value), obtaining The torque upper limit value is output as T _{lim +} .

  By controlling in this way, the motor 9 is operated in the range of the torque upper limit value that outputs the maximum torque range that can be output by the motor 9 at the time of acceleration. Is set to suppress the torque range that can be output. With such a configuration, it is possible to suppress the torque range to give priority to suppression of overcurrent.

<Fourth embodiment>
Next, an electric motor control apparatus 100 according to a fourth embodiment of the present invention will be described.

  The fourth embodiment is a modification of the second embodiment, and the configurations of the torque upper limit calculation processing unit 1 and the UVW phase-dq axis conversion unit 12 are different from those of the first embodiment. Since the other configuration is the same as that of the first embodiment, the same reference numeral is given to the same configuration, and the description thereof is omitted.

  FIG. 16 is an explanatory diagram of the motor control device 100 according to the fourth embodiment of the present invention.

UVW phase -dq axis conversion unit 12, a driving current value i _u, i _v of the motor 9 current detector 8 detects, from the electrical angle detection value of the motor 9 the rotor position sensor 10 detects, dq axes Current values i _d and i _q are calculated. The calculated dq-axis current values i _d and i _q are output to the torque upper limit calculation processing unit 1.

Based on the input rotation speed detection value N, battery voltage V _dc , and dq axis current values i _d and i _q , the torque upper limit calculation processing unit 1 _{lim +} and negative torque upper limit value T _lim- are calculated.

  FIG. 17 is an explanatory diagram of the torque upper limit calculation processing unit 1 according to the fourth embodiment of the present invention.

  The torque upper limit calculation processing unit 1 includes a normal positive torque upper limit table 111, a normal negative torque upper limit table 112, a second positive torque upper limit table 121, a second negative torque upper limit table 122, and a switching unit 141. , A switching unit 142 and a rapid deceleration detection unit 171 are provided.

Rapid deceleration detecting unit 171, the current value i _d of the dq axis output from the UVW phase -dq axis conversion section 12, based on i _q, determines whether rapid deceleration current operating conditions.

Specifically, the rapid deceleration detection unit 171 determines whether or not the vehicle is suddenly decelerated based on i _d and i _q according to the following Expression 13. That is, the current value _{iα_TH} applied to the motor 9 is calculated from the current value of the dq axis, and it is determined whether or not rapid deceleration is performed based on the magnitude of the calculated current value.

  If the calculation result based on Expression 13 is Lo, the sudden deceleration detection unit 171 determines that the deceleration is not sudden. In this case, the rapid deceleration detection unit 171 outputs Lo to the switching unit 141 and the switching unit 142.

  On the other hand, when the calculation result based on Expression 13 is Lo, it is determined that rapid deceleration has occurred. In this case, the rapid deceleration detection unit 171 outputs Hi to the switching unit 141 and the switching unit 142.

  The switching unit 141 and the switching unit 142 that have received Hi from the sudden deceleration detection unit 171 replace the normal positive torque upper limit value table 111 and the normal negative torque upper limit value table 112 with the second positive torque upper limit value table 121 and A switching signal is sent so as to output the calculation result of the second negative torque upper limit value table 122.

Thus, the positive maximum torque calculated by the second positive torque upper limit value table 121 or the second negative torque upper value table 122 T _{lim2 +} or the negative side torque limit T _Lim2- is, positive torque upper limit value T It is output to the torque command value limit processing unit 2 as _{lim +} or negative torque upper limit value _Tlim- .

In the fourth embodiment of the present invention, the torque upper limit calculation processing unit 1 for calculating the positive torque upper limit value T _{lim +} and the negative torque upper limit value T _lim− for limiting the command torque T ^* is a sudden deceleration detection unit. 171.

Rapid deceleration detecting unit 171, based on the current value of the motor 9, similarly to the rapid deceleration detecting section 131 of the second embodiment described above, when it is detected that a sudden deceleration, the positive maximum torque T _{lim2 +} or The switching units 141 and 142 are switched to output the negative torque upper limit value _Tlim2- .

As a result, the torque upper limit value T _{lim2 +} and the lower limit torque T _lim2 are selected by the torque upper limit value calculation processing unit 1 during sudden acceleration or sudden deceleration in the high torque region, _thereby selecting the torque upper limit value. Can be suppressed.

  By controlling in this way, the motor 9 is operated in the range of the torque upper limit value that outputs the maximum torque range that can be output by the motor 9 during normal operation, while the torque that can be output by the motor 9 during sudden deceleration. The range can be suppressed to a torque range that prioritizes suppression of overcurrent.

<Fifth Embodiment>
Next, an electric motor control apparatus 100 according to a fifth embodiment of the present invention will be described.

  The fifth embodiment is a modification of the third embodiment, and the configuration of the torque upper limit calculation processing unit 1 is different from that of the third embodiment. Since the other configuration is the same as that of the first embodiment, the same reference numeral is given to the same configuration, and the description thereof is omitted.

  FIG. 18 is an explanatory diagram of the torque upper limit calculation processing unit 1 according to the fifth embodiment of the present invention.

  The torque upper value calculation processing unit 1 includes a normal positive torque upper value table 111, a normal negative torque upper value table 112, a second positive torque upper value table 121, a second negative torque upper value table 122, and a weighting processing unit. 151, a weighting processing unit 152, and a current norm calculation unit 191.

Current norm calculating unit 191, the current value i _d of the dq axis output from the UVW phase -dq axis conversion section 12, based on i _q, calculated by the following equation 14, the magnitude of the current (norm) i _a To do.

Positive weighting processing unit 151 and negative weighting processing unit 152, based on the size i _a current which current norm calculating unit 191 calculates, as the upper limit value as the acceleration of the vehicle is large increases, the weighting processing Do.

  Specifically, the positive-side weighting processing unit 151 holds a weighting table as shown in FIG. 19 in advance.

Referring to FIG. 19, in the weighting table, the positive torque upper limit value T _{lim + linearly changes} between T _{lim1 +} and T _{lim2 +} between _iaTH1 and _iaTH2 according to the current magnitude ia. Is set to

The positive side weighting processing unit 151 refers to the weighting table shown in FIG. 19, acquires the torque upper limit value (fourth torque upper limit value) corresponding to the current magnitude ia calculated by the current norm calculation unit 191, The acquired torque upper limit value is output as T _{lim +} .

  By controlling in this way, the motor 9 is operated in the range of the torque upper limit value that outputs the maximum torque range that can be output by the motor 9 at the time of acceleration. Is set to suppress the torque range that can be output. With such a configuration, it is possible to suppress the torque range to give priority to suppression of overcurrent.

DESCRIPTION OF SYMBOLS 1 Torque upper limit calculation process part 2 Torque command value limit process part 3 Torque control part 4 dq axis-UVW phase conversion part 5 PWM conversion part 6 Inverter 7 Battery 8 Current detection part 9 Motor 10 Rotor position sensor 11 Rotation number calculation part DESCRIPTION OF SYMBOLS 12 UVW-dq axis conversion part 31 Current vector control part 32 Voltage phase control part 33 Control switching determination part 34 Control node switching part 100 Control apparatus 101 Positive side torque upper limit value table 102 Negative side torque upper limit value table 103 Low-pass filter (LPF)
105 Select Lo Unit 106 Select Hi Unit 111 Normal Positive Torque Upper Value Table 112 Normal Negative Torque Upper Value Table 121 Second Positive Torque Upper Value Table 122 Second Negative Torque Upper Value Table 131 Rapid Deceleration Detection Unit 141 Switching Unit 142 switching unit 151 positive side weighting processing unit 152 negative side weighting processing unit 160 acceleration detection unit 161 acceleration calculation unit 171 sudden deceleration detection unit 191 current norm calculation unit

Claims (7)

In a motor control device that calculates a drive torque command value of an electric motor according to a torque command and drives the electric motor,
A torque upper limit calculation processing unit that calculates a torque upper limit of the electric motor according to the rotation speed of the electric motor;
A torque command value limiting unit that limits the torque command based on the torque upper limit value and calculates a drive torque command value of the electric motor based on the limited torque command;
An electric motor controller that outputs electric power for driving the electric motor to the electric motor based on the calculated driving torque command value;
With
The torque command value limiter is
Calculating a delayed torque upper limit value obtained by delaying the torque upper limit value by a predetermined response;
A control apparatus for an electric motor that compares the torque upper limit value with the calculated delay torque upper limit value, and limits the torque command value with a smaller one of absolute values as a result of comparison. The motor control device according to claim 1,
The torque command value limiting unit corrects the torque upper limit value according to at least one of an amount of change per hour in the rotation speed of the electric motor and a current value applied to the electric motor. The motor control device according to claim 2,
The torque command value limiter is
Calculating a second torque upper limit value smaller than the first torque upper limit value,
Calculate the amount of change per hour in the rotation speed of the motor,
When the calculated amount of change is smaller than a predetermined value, the torque command value is limited using the second torque upper limit value,
An electric motor control device that limits the torque command value using the first torque upper limit value when the calculated change amount is larger than a predetermined value. The motor control device according to claim 2,
The torque command value limiter is
Calculating a second torque upper limit value smaller than the first torque upper limit value;
Calculate the amount of change per hour of the rotation speed of the electric motor,
According to the calculated amount of change, a third torque upper limit value in which weighting is changed between the first torque upper limit value and the second torque upper limit value is calculated,
An electric motor control device that limits the torque command value using the calculated third torque upper limit value. The motor control device according to claim 2,
The torque command value limiter is
Calculating a second torque upper limit value smaller than the first torque upper limit value,
Detecting a current value applied to the electric motor;
An electric motor control device that limits the torque command value using the second torque upper limit value instead of the first torque upper limit value when the detected current value is larger than a predetermined value. The motor control device according to claim 2,
The torque command value limiter is
Calculating a second torque upper limit value whose absolute value is smaller than the first torque upper limit value;
Detecting a current value applied to the electric motor;
In accordance with the calculated magnitude of the current, a fourth torque upper limit value is calculated by changing the weight between the first torque upper limit value and the second torque upper limit value,
A motor control device that limits the torque command value using the calculated fourth torque upper limit value. In the control method of the electric motor that calculates the drive torque instruction value of the electric motor according to the torque instruction and drives the electric motor,
According to the rotation speed of the electric motor, to calculate the torque upper limit value of the electric motor,
Calculating a delayed torque upper limit value obtained by delaying the torque upper limit value by a predetermined response;
The torque upper limit value is compared with the calculated delay torque upper limit value, and as a result of the comparison, the torque command value is limited by the smaller one of the absolute values,
Limiting the torque command based on the torque upper limit value, calculating a drive torque command value of the electric motor based on the limited torque command,
An electric motor control method for outputting electric power for driving the electric motor to the electric motor based on the calculated driving torque command value.

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