JP5446294B2 - Drive control device for rotating electrical machine - Google Patents

Description

  The present invention relates to a drive control device for a rotating electrical machine that employs a technique for improving responsiveness during motor rotation.

  Conventionally, as this type of technology, for example, those described in the following documents are known (see Patent Document 1). In this document, during acceleration of the motor, the linear current for suppressing the terminal voltage of the motor is remarkably increased by increasing / decreasing in proportion to the rotation angle of the motor with a preset proportional constant as a variable. Since the terminal voltage is less likely to be saturated, an invention that realizes stable acceleration is described.

JP 2002-320400 A

  In the above conventional motor control method, saturation of the terminal voltage of the motor is suppressed, but the terminal voltage cannot be increased rapidly. For this reason, when it is desired to increase the torque of the motor, it has been difficult to quickly generate the required torque.

  Accordingly, the present invention has been made in view of the above, and an object of the present invention is to provide a drive control device for a rotating electrical machine with improved responsiveness when torque is increased.

In order to achieve the above object, the means for solving the problems of the present invention is to increase the driving voltage by the boosting means when the torque of the rotating electrical machine is set to a transient upper limit torque that is larger than the steady upper limit torque. with increasing the transient limit current, as the torque command value of the boost state of the driving voltage, Ru set Teisu up to become torque within the torque range of possible in the boosted boosted drive voltage and transient upper limit current It is characterized by that.

  According to the present invention, the torque of the rotating electrical machine can be quickly increased by setting the current command value to a transient upper limit current larger than the steady upper limit current by the drive control means.

It is a figure which shows the structure of the drive control apparatus of the rotary electric machine which concerns on Example 1 of this invention. It is a figure which shows the increase method of the torque in the output characteristic area | region of a motor. It is a figure which shows the time change of the electric current at the time of changing a torque. It is a figure which shows the mode of the torque change with respect to each quantity of a motor. It is a figure which shows the time change of junction temperature at the time of increasing torque. It is a figure which shows the time change of the voltage at the time of changing a torque, and an electric current. It is a figure which shows the mode of the torque change with respect to each quantity of a motor.

  Embodiments for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration of a drive control device for a rotating electrical machine according to a first embodiment of the present invention. The drive control apparatus according to the first embodiment shown in FIG. 1 is an apparatus for driving and controlling the motor 100 by vector control of a d-axis current and a q-axis current in a conventionally known dq coordinate system, and includes a torque command unit 101, a current command value calculation. Unit 102 and current control unit 103.

  The torque command unit 101 inputs parameters for determining the torque required for the motor 100, and based on these parameters, represents the relationship between the parameters prepared and prepared in advance based on the results of experiments and desk studies and torque command values. The torque command value τ is calculated with reference to the map or the like. The parameter for determining the torque command value varies depending on the load of the motor 100. For example, in the case of a motor mounted on an electric vehicle, in this embodiment, an accelerator signal indicating the rotational speed ω of the motor 100, the accelerator opening degree, and the depression amount. The vehicle body vibration signal is obtained by quantifying (quantifying) the vibration of the vehicle body. The torque command value obtained by the torque command unit 101 is given to the current command value calculation unit 102.

  Based on the torque command value, the current command value calculation unit 102 calculates a d-axis current command value idr and a q-axis current command value iqr with reference to a map or the like. The map to be referred to is prepared and prepared in advance based on the results of experiments and desk studies. The current command value and the rotational speed ω of the motor 100 that determines the current command value, the boost voltage Vdc obtained by a booster circuit to be described later. It represents the relationship with parameters including. The current command value obtained by the current command value calculation unit 102 is given to the current control unit 103. The current command value calculation unit 102 estimates a junction temperature of the inverter 106 described later, and sets a current command value based on the estimated junction temperature.

  The current control unit 103 refers to a map or the like so that the d-axis actual current id and the q-axis actual current iq match the d-axis current command value idr and the q-axis current command value iqr, respectively. Voltage command value Vdr and q-axis voltage command value Vqr are calculated. This reference map is prepared and prepared in advance based on the results of experiments and desk studies, and represents the relationship between the voltage command value and the current command value and the actual voltage that determine this voltage command value. The voltage command value obtained by the current control unit 103 is given to the dq → 3φ unit 104.

  The dq → 3φ unit 104 sets the d-axis voltage command value and the q-axis voltage command value to 3 based on the phase of the dq coordinate system viewed from the three-phase AC coordinate system obtained from the rotational position θ of the motor 100. Convert to phase AC voltage command value. The three-phase AC voltage command value obtained by the dq → 3φ unit 104 is given to the PWM generation unit 105.

  The PWM generator 105 generates a PWM pulse signal for switching control by PWM (pulse width modulation) control from the three-phase AC voltage command value obtained by the dq → 3φ unit 104. The generated PWM pulse signal is supplied to the inverter 106.

  The inverter 106 generates three-phase AC power by switching control of DC power supplied from a DC power source 108 such as a battery via the booster circuit 107 based on the PWM pulse signal generated by the PWM generator 105. The three-phase AC power is supplied to the motor 100 to drive the motor 100. The three-phase alternating current (iu, iv, iw) generated by the inverter 106 and supplied to the motor 100 is given to the dq ← 3φ section 109.

  The booster circuit 107 is configured to be capable of instantaneously boosting the output voltage of the DC power source 108 serving as the power source of the inverter 106 in a short time, and supplies the boosted DC voltage to the inverter 106 and the current command value calculation unit 102.

  The dq ← 3φ unit 109 converts the three-phase AC current of the motor 100 into the d-axis actual current id and the d-axis AC current based on the phase of the dq coordinate system viewed from the three-phase AC coordinate system obtained from the rotational position θ of the motor 100. Conversion into q-axis actual current iq. Each actual current obtained by the dq ← 3φ unit 109 is given to the current control unit 103.

  The motor 100 is provided with an encoder 110, and the encoder 110 detects the rotational position θ of the motor 100. The rotational position θ detected by the encoder 110 is given to the dq → 3φ unit 104, the dq ← 3φ unit 109, and the speed detection unit 111.

  The speed detector 111 calculates the rotational speed ω of the motor 100 based on the rotational position θ of the motor 100. The rotation speed ω obtained by the speed detection unit 111 is given to the torque command unit 101 and the current command value calculation unit 102.

  In such a configuration, in this embodiment, as a method for instantaneously increasing the torque of the motor 100, the constant torque region (1) and the equal power region (2) in the diagram showing the relationship between the output and the torque in FIG. I am trying to change the method of increase.

  First, in the constant torque region (1) of FIG. 2, since there is a margin with respect to the steady upper limit voltage (Vmax), the target torque is changed from the steady upper limit torque (Tmax) to the transient upper limit torque (T′max) as shown in FIG. ) And the current command value is increased from the steady upper limit current (Imax) to the transient upper limit current (I′max) as indicated by point B in FIG. The maximum torque that can be taken in such a state of the transient upper limit current (I′max) is selected.

  That is, as shown in FIG. 4 showing the relationship between the d-axis current, the q-axis current and the torque, the upper limit current, and the upper limit current, the current is changed from the steady upper limit current (Imax) to the transient upper limit current within the range of the steady voltage (Vmax). By increasing to (I′max), the target torque is instantaneously increased from the steady upper limit torque (Tmax) to the transient upper limit torque (T′max).

  Thus, when the current command value exceeds the steady upper limit current, the junction temperature (Tj) of a switching element such as an IGBT constituting the inverter 106 increases. Therefore, this junction temperature is estimated and monitored using an estimation model described later, and the current command value is controlled so as not to exceed the upper limit value.

  That is, as shown in FIG. 5 showing the time variation of the junction temperature (Tj), when the current command value is raised to the transient upper limit current (I′max) at the point B, the junction temperature (Tj) gradually increases. . In this state, the junction temperature (Tj) exceeds the upper limit junction temperature (Tj_max). Therefore, at the point C that reaches a preset threshold value (Tj_th <Tj_max), the time elapses as shown in FIG. The current command value is decreased from the transient upper limit current (I′max) together with C → D → A). As a result, the junction temperature (Tj) is prevented from exceeding the upper limit junction temperature (Tj_max).

  With such control of the current command value, the target torque becomes torque B (transient upper limit torque (T′max)) → torque C (with time elapse (B → C → D → A) as shown in FIG. > Tmax) → torque D (> Tmax) → torque A (= Tmax).

  Thus, in the steady torque region, the target torque can be instantaneously increased without causing the junction temperature to exceed the upper limit value by transiently increasing the current within a range where the junction temperature does not exceed the upper limit value. Thereby, it becomes possible to improve the responsiveness at the time of torque increase. Therefore, when a motor having such a torque response is used as a drive motor for an electric vehicle, the transmission delay of the drive transmission system from the motor to the wheels can be ensured by an instantaneous torque increase, and the vibration of the vehicle body Can be reduced.

  Next, in the equal power region (2) shown in FIG. 2, since the target torque is related to the steady upper limit voltage (Vmax), the power supply voltage supplied to the inverter 106 by the booster circuit 107 is instantaneously boosted, so that FIG. As shown, the target voltage is instantaneously raised from the steady voltage (Vmax) to the transient upper limit voltage (V′max). As a result, the current is instantaneously increased to the transient upper limit current (I′max) corresponding to the transient upper limit voltage (V′max).

  As shown in FIG. 7, the torque in such a state is a torque characteristic curve at an intersection B where the characteristic curve of the transient upper limit voltage (V′max) and the characteristic curve of the transient upper limit current (I′max) intersect. Therefore, the maximum possible torque (torque B) is selected and set.

  In this way, after the target torque instantaneously increases with the boost of the power supply voltage, the boostable time determined by the specification performance of the booster circuit 107 elapses, and as the boosted voltage decreases, the voltage becomes the transient upper limit voltage (V ′ from max). The target torque at this time is the maximum torque (Vmax) that can be taken on the characteristic curve of the steady voltage (Vmax) based on the steady voltage (Vmax) at this time and the estimated junction temperature (Tj) as shown in FIG. Torque C) is selected.

  Thereafter, the current is reduced from the transient upper limit current (I′max) so that the junction temperature (Tj) does not exceed the junction upper limit temperature (Tj_max). Accordingly, as shown in FIG. 7, the maximum torque (torque D) that can be taken is selected and set according to the steady current (Imax) calculated from the junction temperature (Tj) at that time and the torque characteristic curve.

  When the current further decreases, the target torque at this time becomes the maximum torque (torque A) determined according to the intersection of the characteristic curve of the steady current (Imax) and the characteristic curve of the steady voltage (Vmax) and the torque characteristic curve. Thus, since there is a difference between the boostable time of the booster circuit 107 and the current increaseable time when the current increases, the target torque (torque command value) decreases to a steady voltage as shown in FIG. The torque B is shifted from the maximum torque B that can be increased in the order of torque C → torque D → torque A.

  By adopting such a control method, the same effect as in the constant torque region (1) can be obtained in the equal power region (2).

  Various estimation methods (estimation models) have been proposed for the junction temperature (Tj) described above. For example, the junction heat capacity (Cj-c) and the thermal resistance are based on the base plate temperature (Tc) of the switching element. It can be estimated by adding a rising temperature calculated based on a junction-base plate thermal time constant (τj) calculated as a product of (Rj−c).

  The time until the junction temperature (Tj) estimated in this way reaches the above-described threshold value, and the current command value set so far, is maintained, so that the junction temperature exceeds the upper limit value while securing the torque. It can be avoided.

  Alternatively, the junction temperature is monitored for each switching element constituting the inverter 106, and when the highest junction temperature reaches the threshold value, the current command value is lowered to suppress the increase in the junction temperature. Alternatively, the junction temperature is monitored for each phase of the inverter 106, and if there is a phase junction temperature that reaches the inner threshold value of the junction temperature set for each phase, the current command value is lowered to suppress the increase in the junction temperature. Thereby, the same effects as described above can be obtained.

DESCRIPTION OF SYMBOLS 100 ... Motor 101 ... Torque command part 102 ... Current command value calculating part 103 ... Current control part 104 ... dq-> 3 (phi) part 105 ... PWM production | generation part 106 ... Inverter 107 ... Booster circuit 108 ... DC power supply 109 ... d-q <- 3φ section 110 ... encoder 111 ... speed detection section

Claims (5)

When setting the torque command value of the torque required for the rotating electrical machine to a transient upper limit torque larger than the steady upper limit torque, the current command value for commanding the drive current supplied to the rotating electrical machine is set to a transient upper limit current larger than the steady upper limit current. Drive control means for setting and controlling ,
Have a step-up means for boosting the driving voltage supplied to the rotary electric machine,
The drive control means boosts the drive voltage by the boosting means, increases the steady upper limit current to the transient upper limit current, and uses the boosted boost drive voltage and the transient upper limit current as a torque command value in the boost state of the drive voltage. A drive control device for a rotating electrical machine , wherein a maximum torque is set within a range of torques that can be taken . An estimation means for estimating a junction temperature of a power conversion element constituting power supply means for supplying driving power to the rotating electrical machine;
The drive control means sets a torque that is maximum within a range of torque that can be taken by the transient upper limit current calculated based on the boosted boost drive voltage and the junction temperature estimated by the estimation means. The drive control device for a rotating electrical machine according to claim 1. Before SL drive control means to set the maximum and becomes torque within the torque range of possible in a steady upper limit current which is calculated based on the drive voltage and the estimated junction temperature when the decreased after boost The drive control device for a rotating electrical machine according to claim 2, characterized in that: Before SL drive control means, when the junction temperature estimated exceeds a preset threshold, the drive control device for a rotary electric machine according to claim 3, characterized in that to lower the current command value. It said drive control means of the rotating electrical machine according to any one of claims 1 to 4, characterized in Rukoto lower the torque command value set to the maximum torque with decreasing boosted boosted drive voltage Drive control device.

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