JP6361540B2 - Control device for rotating electrical machine - Google Patents

Description

  The present invention relates to a control device for a rotating electrical machine that controls a control amount of the rotating electrical machine based on a detected value of a phase current flowing in a three-phase AC rotating electrical machine.

  The current detection value of the current detection unit that detects the phase current flowing through the three-phase AC rotating electric machine may include a current error that depends on the temperature of the current detection unit. If the current error is included, there is a concern that the controllability of the control amount may be lowered, for example, the control amount of the rotating electrical machine varies. For this reason, it is required to correct the current detection value based on the temperature detection value of the temperature detection unit that detects the temperature of the current detection unit.

  Therefore, there is a technique described in Patent Document 1 below as a technique for realizing this requirement. Specifically, this technique is applied to a control system including three current detection units provided corresponding to each of the three phases and three temperature detection units provided corresponding to the respective current detection units. Is. According to this technique, the current detection value of the current detection unit can be corrected for each of the three phases based on the temperature detection value of the temperature detection unit. Thereby, the influence which the electric current error contained in an electric current detection value has on the controllability of the control amount of a rotary electric machine can be suppressed.

Japanese Patent No. 3710673

  Here, in the technique described in Patent Document 1, it is required to provide the control system with temperature detection units for three phases. For this reason, there is a concern about an increase in the number of parts.

  The main object of the present invention is to provide a control device for a rotating electrical machine that can improve the detection accuracy of a phase current used for control of a control amount while suppressing an increase in the number of components.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  The present invention is provided corresponding to each of the power conversion circuit (20) energized to apply an AC voltage to the three-phase AC rotating electric machine (10) and the three phases of the rotating electric machine (10), A current detection unit (24u, 24v, 24w) for detecting a phase current flowing in the rotating electrical machine, and a temperature detection unit (27) that uses a one-phase current detection unit as a temperature detection target among the three-phase current detection units; The current detection unit that is a temperature detection target of the temperature detection unit is a first control current detection unit (24u), and among the three-phase current detection units, the first One other than the one control current detection unit is a first current detection unit and the other is a second current detection unit. Based on the temperature detection value of the temperature detection unit, the current detection value of the first control current detection unit is First correction means for correcting to one correction current value; For each of the control current detection unit, the first current detection unit, and the second current detection unit, the amount of temperature increase associated with the current flowing through the phase in which the control current detection unit is provided is estimated. A temperature rise amount estimation means for performing calculation, a reference temperature calculation means for calculating a value obtained by subtracting the temperature rise amount of the first control current detection section from the temperature detection value of the temperature detection section, and the first control. A deviation between the temperature increase amount of the current detection unit and the temperature increase amount of the first current detection unit is defined as a first deviation, and the temperature increase amount of the first control current detection unit and the second current detection unit of the second current detection unit The current detection unit that detects a phase current corresponding to a smaller one of the first deviation and the second deviation, the deviation from a temperature rise amount being a second deviation, wherein the first control current detection unit Second control of current detectors other than Estimated by the temperature estimating means for estimating the temperature of the second control current detecting section by adding the reference temperature to the amount of temperature increase of the second control current detecting section as a current detecting section. Second correction means for correcting the current detection value of the second control current detection unit to a second correction current value based on the temperature of the second control current detection unit, and the first correction current value and the first correction current value. Control means (30c, 30g, 30h, 30i; 30c, 30m, 30p) for controlling the amount of control of the rotating electrical machine by energizing the power conversion circuit based on two correction current values. Features.

  The present invention is applied to a control system for a rotating electrical machine including three current detection units capable of detecting each phase current and one temperature detection unit capable of detecting the temperature of a one-phase current detection unit. In this control system, the number of temperature detection units is reduced to suppress an increase in the number of components. In this control system, current control values for at least two phases are required for controlling the control amount of the rotating electrical machine. For this reason, in the present invention, the first current detection value used for controlling the control amount of the rotating electrical machine, and the current detection value of the first control current detection unit that is the temperature detection target of the temperature detection unit is the temperature detection value. The first correction current value is corrected based on the temperature detection value of the detection unit. On the other hand, the second current detection value used for control amount control is temperature-corrected by the method described below.

  In the present invention, the temperature rise amount estimation means causes each of the first control current detection unit, the first current detection unit, and the second current detection unit to receive a current in a phase in which it is provided based on its own current detection value. The amount of temperature rise associated with the flow is estimated. Then, a value obtained by subtracting the temperature increase amount of the first control current detection unit from the temperature detection value of the temperature detection unit is calculated as the reference temperature.

  In the present invention, the deviation between the temperature rise amount of the first control current detector and the temperature rise amount of the first current detector is defined as the first deviation, and the temperature rise amount of the first control current detector and the second current detector The deviation from the temperature rise amount is defined as a second deviation. A current detection unit that detects a phase current corresponding to the smaller one of the first deviation and the second deviation, and uses a current detection unit other than the first control current detection unit for control amount control. Let it be a current detector. The above-described selection method of the second control current detection unit reduces the temperature estimation variation of the second control current detection unit with respect to the temperature of the first control current detection unit detected by the temperature detection unit, and thus improves the detection accuracy of the phase current. Used to improve.

  That is, among the three current detection units, the current detection unit to be used as a reference is the first control current detection unit used for calculating the reference temperature. When the estimated value of the temperature rise amount of the first control current detector is used as a reference, the temperature rise of the second control current detector among the first current detector and the second current detector is closest to the estimated value. This is an estimate of the quantity. Therefore, by using the above-described selection method of the second control current detection unit, it is possible to select one of the first current detection unit and the second current detection unit that has a smaller temperature estimation variation and use it for the control.

  The temperature of the second control current detector is estimated by adding the reference temperature to the estimated value of the temperature rise amount of the second control current detector selected by the above-described method. Then, based on the estimated temperature of the second control current detector, the current detection value of the second control current detector is corrected to the second correction current value. Then, the control amount of the rotating electrical machine is controlled based on the first correction current value and the second correction current value. Thereby, the fall of controllability of control amount, such as a fluctuation | variation of control amount, can be suppressed.

  Thus, according to the present invention, it is possible to improve the detection accuracy of the phase current used for controlling the control amount while suppressing an increase in the number of components.

1 is an overall configuration diagram of a motor control system according to a first embodiment. The block diagram which shows an electric current feedback control process. The figure which shows an electric current error. The figure which shows the torque fluctuation | variation resulting from an electric current error. The flowchart which shows a series of processes which a control phase selection part performs. The flowchart which shows the procedure of a temperature estimation process. The figure which shows the outline | summary of the temperature estimation method of an electric current sensor. The flowchart which shows the procedure of the temperature correction process of an electric current detection value. The time chart which shows the relationship between the rotational speed of a motor generator, and a phase current. The flowchart which shows the procedure of a current sensor selection process. The block diagram which shows the torque feedback control process concerning 2nd Embodiment.

(First embodiment)
Hereinafter, a first embodiment in which a control device for a rotating electrical machine according to the present invention is applied to a vehicle (for example, an electric vehicle or a hybrid vehicle) including a three-phase rotating electrical machine as an in-vehicle main machine will be described with reference to the drawings.

  As shown in FIG. 1, the motor control system includes a motor generator 10, a three-phase inverter 20 as a “power conversion circuit”, and a control device 30 that controls the motor generator 10. In the present embodiment, a permanent magnet synchronous machine is used as the motor generator 10, and more specifically, an IPMSM that is a salient pole machine is used.

  The motor generator 10 includes a stator (not shown) having a U-phase coil 10u, a V-phase coil 10v, and a W-phase coil 10w, and a rotor (not shown) having a permanent magnet and mechanically coupled to drive wheels. . These coils 10u, 10v, and 10w are Y-connected by connecting the first ends of the coils at a neutral point.

  The motor generator 10 is connected to a battery 21 as a DC power source via an inverter 20. The output voltage of the battery 21 is, for example, 100 V or more. A smoothing capacitor 22 that smoothes the input voltage of the inverter 20 is provided between the battery 21 and the inverter 20. Incidentally, a step-up / down converter may be provided between the battery 21 and the inverter 20 in the control system.

  The inverter 20 includes three sets of serially connected bodies of upper arm switches Sup, Svp, Swp and lower arm switches Sun, Svn, Swn. A second end of the U-phase coil 10u is connected to a connection point between the U-phase upper and lower arm switches Sup and Sun via a U-phase bus bar 23u which is a conductive member. A second end of the V-phase coil 10v is connected to a connection point between the V-phase upper and lower arm switches Svp and Svn via a V-phase bus bar 23v. A second end of the W-phase coil 10w is connected to a connection point between the W-phase upper and lower arm switches Swp and Swn via a W-phase bus bar 23w. Incidentally, in the present embodiment, voltage controlled semiconductor switching elements are used as the switches SUp to SWn, and more specifically, IGBTs are used. And each freewheel diode DUp-DWn is connected to each switch SUp-SWn in antiparallel.

  The control system includes U, V, and W phase current sensors 24 u, 24 v, and 24 w (corresponding to “current detection unit”) that detect currents flowing through the U, V, and W phases of the motor generator 10. In this embodiment, each phase current sensor 24u, 24v, 24w is directly attached in the state which contacted each phase bus-bar 23u, 23v, 23w. In the present embodiment, as each phase current sensor 24u, 24v, 24w, a current sensor including a GMR (Giant Magneto Resistive) element is used. In the present embodiment, the reason why the current sensor including the GMR element is used is to reduce the size of the current sensor. That is, conventionally, a current sensor having a Hall element has been used. When using a current sensor having a Hall element, a magnetic core and a coil are required. On the other hand, when a current sensor including a GMR element is used, a magnetic core and a coil can be omitted.

  The control system also includes a voltage sensor 25 that detects the power supply voltage of the inverter 20 (voltage between terminals of the smoothing capacitor 22), and a rotation angle sensor 26 that detects the rotation angle (electrical angle θe) of the motor generator 10 (for example, a resolver). And. The control system further includes one temperature sensor 27 (corresponding to a “temperature detector”) that detects the temperature of one predetermined current sensor among the phase current sensors 24u, 24v, and 24w. In the present embodiment, the temperature sensor 27 uses a U-phase current sensor 24u (corresponding to a “first control current detection unit”) as a temperature detection target.

  The control device 30 is configured mainly with a microcomputer, and controls the energization operation of the inverter 20 so as to feedback-control the control amount (torque in the present embodiment) of the motor generator 10 to a command value (hereinafter, command torque Trq *). Means. Specifically, the control device 30 generates operation signals gup to gwn corresponding to the switches Sup to Swn based on the detection values of the various sensors in order to turn on and off the switches Sup to Swn constituting the inverter 20. The generated operation signals gup to gwn are output to the switches Sup to Swn. Here, the operation signals gup, gvp, gwp of the upper arm switches Sup, Svp, Swp and the operation signals gun, gvn, gwn of the corresponding lower arm switches Sup, Svp, Swp are complementary to each other. Yes. That is, the upper arm switches Sup, Svp, Swp and the corresponding lower arm switches Sun, Svn, Swn are alternately turned on. The command torque Trq * is, for example, a control device provided outside the control device 30, and is input to the control device 30 from a control device higher than the control device 30.

  Next, torque control of the motor generator 10 executed by the control device 30 will be described using FIG. In the present embodiment, current feedback control is performed as torque control.

  The speed calculation unit 30 a calculates the electrical angular speed ω of the motor generator 10 based on the electrical angle θe detected by the rotation angle sensor 26.

  The control phase selection unit 30b corrects the temperature of the U-phase current Iu detected by the U-phase current sensor 24u, which is a temperature detection target of the temperature sensor 27, and corrects the corrected U-phase current Iu (hereinafter, U-phase corrected current value Iuc). Is output to the two-phase converter 30c. The control phase selector 30b also performs temperature correction on the V and W phase currents Iv and Iw detected by the V and W phase current sensors 24v and 24w, and corrects these phase currents Iv and Iw (hereinafter referred to as V and W phases). One of the corrected current values Ivc, Iwc) is selected and output to the two-phase converter 30c. The processing of the control phase selection unit 30b will be described in detail later.

  The two-phase conversion unit 30c is configured to generate a U-phase current Iu, a V-phase current Iv, and a W-phase current in the three-phase fixed coordinate system based on the two-phase current output from the control phase selection unit 30b and the electrical angle θe. Iw is converted into a d-axis current Idr and a q-axis current Iqr in a two-phase rotating coordinate system (dq coordinate system). Here, the current of the remaining one phase can be calculated according to Kirchhoff's law based on the current of two phases output from the control phase selector 30b. Kirchoff's law indicates that the sum of U, V, and W phase currents is theoretically zero.

  The command current setting unit 30d sets the d and q axis command currents Id * and Iq * based on the command torque Trq *. The d-axis deviation calculating unit 30e calculates the d-axis current deviation ΔId as a value obtained by subtracting the d-axis current Idr from the d-axis command current Id * set by the command current setting unit 30d. The q-axis deviation calculating unit 30f calculates the q-axis current deviation ΔIq as a value obtained by subtracting the q-axis current Iqr from the q-axis command current Iq * set by the command current setting unit 30d.

  The d-axis command voltage calculation unit 30g calculates the d-axis command voltage Vd * as an operation amount for performing feedback control of the d-axis current Idr to the d-axis command current Id * based on the d-axis current deviation ΔId. Specifically, the d-axis command voltage Vd * is calculated by proportional-integral control using the d-axis current deviation ΔId as an input. The q-axis command voltage calculation unit 30h calculates the q-axis command voltage Vq * as an operation amount for feedback-controlling the q-axis current Iqr to the q-axis command current Iq * based on the q-axis current deviation ΔIq.

  The three-phase conversion unit 30i determines the d and q-axis command voltages in the two-phase rotating coordinate system based on the d and q-axis command voltages Vd * and Vq *, the power supply voltage Vsys detected by the voltage sensor 25, and the electrical angle θe. Vd * and Vq * are converted into U, V, and W phase command voltages Vu *, Vv *, and Vw * in a three-phase fixed coordinate system. In the present embodiment, the U, V, and W phase command voltages Vu *, Vv *, and Vw * are sinusoidal waveforms that are 120 degrees out of phase with each other in electrical angle.

  The operation signal generation unit 30j generates the operation signals gup, gvp, gwp, gun, gvn, and gwn based on the three-phase command voltages Vu *, Vv *, and Vw *. In this embodiment, each operation signal gup, gvp, gwp, gun, gvn, gwn is obtained by PWM processing based on a magnitude comparison between the three-phase command voltages Vu *, Vv *, Vw * and a carrier signal (for example, a triangular wave signal). Generate. The operation signal generation unit 30j outputs the generated operation signals gup, gvp, gwp, gun, gvn, and gwn to the switches Sup, Svp, Swp, Sun, Svn, and Swn. Note that the method of generating each operation signal is not limited to the method using PWM processing, and for example, a method using a pulse pattern may be used.

  Next, the control phase selection unit 30b will be described. In the present embodiment, first, the reason why the control device 30 includes the control phase selector 30b will be described, and then the processing of the control phase selector 30b will be described.

  The control phase selection unit 30b is provided to avoid a decrease in torque controllability due to the fact that each phase current Iu, Iv, Iw detected by each phase current sensor 24u, 24v, 24w includes a current error. Because. As shown in FIG. 3, the current error is composed of an offset error and a gain error. The offset error is an error in which the detected current value deviates from the actual phase current by a predetermined value regardless of the actual phase current (true value). The gain error is an error whose absolute value increases as the phase current increases. The offset error and gain error depend on the temperature of the current sensor. Specifically, the absolute values of the offset error and the gain error increase as the temperature of the current sensor increases from the temperature (for example, 25 ° C.) serving as the current sensor reference.

  In this embodiment, each phase current sensor 24u, 24v, 24w was directly attached to each phase bus bar 23u, 23v, 23w. When the phase current flows through each phase bus bar 23u, 23v, 23w, each phase bus bar 23u, 23v, 23w generates heat. For this reason, each phase current Iu, Iv, Iw detected by each phase current sensor 24u, 24v, 24w tends to include a current error having temperature dependence. In this case, an error between each phase current Iu, Iv, Iw detected by each phase current sensor 24u, 24v, 24w and the actual phase current increases, and torque fluctuation of motor generator 10 occurs.

  Specifically, for example, when an offset error is included in the U-phase current Iu, as shown in FIG. 4, the average torque value of the motor generator 10 fluctuates in the electrical primary (electrical angle 1 period = 360 °). For example, when a gain error is included in the U-phase current Iu, the torque average value fluctuates in an electrical secondary (electrical angle 0.5 cycle = 180 °). When torque fluctuation occurs, the vehicle vibrates and the ride comfort of the vehicle may deteriorate.

  Therefore, in order to solve the above-described problem, the control phase selection unit 30b is provided in the control device 30. Hereinafter, the process performed by the control phase selection unit 30b will be described with reference to FIGS.

  FIG. 5 shows a procedure of processing performed by the control phase selection unit 30b. This process is repeatedly executed by the control phase selection unit 30b, for example, at a predetermined cycle.

  In this series of processing, first, in step S10, the U, V, W phase currents Iu, Iv, Iw detected by the phase current sensors 24u, 24v, 24w and the temperature detected by the temperature sensor 27 (hereinafter referred to as U). And the phase temperature detection value Tu). Thereafter, the temperature estimation process in step S20, the correction process in step S30, and the current sensor selection process in step S40 are sequentially performed.

  FIG. 6 shows a procedure of temperature correction processing according to the present embodiment.

  In the temperature correction process, in step S21 (“corresponding to the temperature rise estimation means”), the U, V, W phase temperature rise ΔTest based on the time integral values of the U, V, W phase currents Iu, Iv, Iw. , ΔTvest, ΔTwest are estimated. The U, V, and W phase temperature rise amounts ΔTuest, ΔTvest, and ΔTwest are the phase current sensors 24u that are generated when the phase bus bars 23u, 23v, and 23w generate heat when the phase current flows through the phase bus bars 23u, 23v, and 23w. , 24v, 24w. In the present embodiment, the U, V, and W phase temperature rise amounts ΔTuest, ΔTbest, and ΔTwest are estimated by the following equation (eq1).

上式（ｅｑ１）において、「Ｒ」は、各相バスバー２３ｕ，２３ｖ，２３ｗにおける各相電流センサ２４ｕ，２４ｖ，２４ｗの取り付け部分の抵抗値を示す。「Ｉ＾２」は、各相電流Ｉｕ，Ｉｖ，Ｉｗの実効値を示し、例えば、各相電流Ｉｕ，Ｉｖ，Ｉｗの複数のサンプリング値に基づいて算出される値である。「Ｋ」は各相バスバー２３ｕ，２３ｖ，２３ｗの材質から定まる値であり、「∫Ｒ×Ｉ＾２×ｄｔ」（Ｗｓ）で表されるエネルギを温度上昇量に換算する係数である。なお、上式（ｅｑ１）において、「Ｉ＾２」の積分時間（ｔ１〜ｔ２）は、例えば、電気角速度ωが後述する閾値速度ωｍｉｎ以下となる場合において、相電流の１周期よりも短い時間に設定すればよい。

In the above equation (eq1), “R” indicates the resistance value of the attachment portion of each phase current sensor 24u, 24v, 24w in each phase bus bar 23u, 23v, 23w. “I ^ 2” indicates an effective value of each phase current Iu, Iv, Iw, and is a value calculated based on a plurality of sampling values of each phase current Iu, Iv, Iw, for example. “K” is a value determined from the material of each phase bus bar 23u, 23v, 23w, and is a coefficient for converting the energy represented by “∫R × I ^ 2 × dt” (Ws) into a temperature rise amount. In the above equation (eq1), the integration time (t1 to t2) of “I ^ 2” is shorter than one cycle of the phase current when the electrical angular velocity ω is equal to or lower than a threshold velocity ωmin described later, for example. Should be set.

  In the subsequent step S22 ("corresponding to the reference temperature calculating means"), the reference temperature Tbest is calculated by subtracting the U-phase temperature increase amount ΔQuest estimated in step S21 from the U-phase temperature detection value Tu. In step S23 (“corresponding to temperature estimation means”), the V-phase temperature estimated value Tbest is calculated by adding the V-phase temperature increase ΔTbest estimated in step S21 to the reference temperature Tbest. Further, the W-phase temperature estimated value Twest is calculated by adding the W-phase temperature increase amount ΔTwest estimated in step S21 to the reference temperature Tbest. The V and W phase temperature estimated values Tvest and Twest can be calculated in this way because the ambient temperatures of the phase current sensors 24u, 24v, and 24w are considered to be substantially equal to each other, as shown in FIG. This is because the temperature Tbest can be handled as a common temperature corresponding to the ambient temperature of each phase current sensor 24u, 24v, 24w.

  Next, FIG. 8 shows a correction processing procedure according to the present embodiment.

  In the correction process, in step S31, it is determined whether or not the absolute value of the electrical angular velocity ω calculated by the velocity calculating unit 30a is higher than the threshold velocity ωmin. This process is a process for determining whether or not the time average values of the actual phase currents are greatly deviated from each other and the actual temperature rise amounts of the respective phases are largely deviated from each other. That is, each of the phase currents Iu, Iv, and Iw is a sinusoidal current whose phases are shifted by 120 ° from each other in electrical angle. Here, in the region where the electrical angular velocity ω is high, as shown in FIG. 9A, the time average values Iaveu, Iavev, and Iavew at the specified time tL of the actual phase currents are substantially equal to each other. This is because a plurality of waveforms for one period of each phase current Iu, Iv, Iw are included in the specified time tL, and the influence of the waveform for one period on the time average value is small. As a result, the actual temperature rise amounts of the respective phases become substantially equal, and the actual temperatures of the respective phase current sensors 24u, 24v, 24w become substantially equal. On the other hand, in the region where the electrical angular velocity ω is low, as shown in FIG. 9B, the time average values Iaveu, Iavev, and Iavew at the specified time tL of the actual phase currents greatly deviate from each other. This is because, for example, one cycle of each phase current does not subside within a specified time tL, and the magnitude relationship of each phase current is biased. As a result, the actual temperature rise amounts of the respective phases are greatly shifted from each other, and the actual temperatures of the respective phase current sensors 24u, 24v, 24w are different from each other.

  Returning to the description of FIG. 8 above, if an affirmative determination is made in step S31, the process proceeds to step S32, where the current error contained in each phase current Iu, Iv, Iw is removed based on the detected U-phase temperature value Tu. Thus, each phase current Iu, Iv, Iw is corrected. The U-phase temperature detection value Tu can be commonly used to correct the phase currents Iu, Iv, and Iw because the actual temperatures of the V and W-phase current sensors 24v and 24w are the actual temperatures of the U-phase current sensor 24u. It is based on the fact that it is substantially equal to the temperature of That is, in the region where the electrical angular velocity ω is high, the actual U, V, and W phase temperature increases are substantially equal to each other as described above. For this reason, the actual temperatures of the V and W phase current sensors 24v and 24w are substantially equal to the U phase temperature detection value Tu.

  In the present embodiment, each phase current Iu, Iv, Iw is corrected to each phase correction current value Iuc, Ivc, Iwc based on temperature characteristic information in which the temperature and current error of the current sensor are previously related by experiments or the like. To do. Specifically, first, a current correction amount for removing a current error is calculated based on the U-phase temperature detection value Tu and temperature characteristic information. Then, each phase current Iu, Iv, Iw is corrected by the current correction amount. By the way, the temperature characteristic information includes the first temperature characteristic information in which the temperature of the current sensor and the offset error are related in advance by experiments, and the second in which the temperature of the current sensor and the gain error are related in advance by experiments. It may be divided into temperature characteristic information.

  On the other hand, when a negative determination is made in step S31, it is determined that the actual temperatures of the phase current sensors 24u, 24v, 24w are greatly different from each other. Therefore, in step S33, first, the U-phase current Iu is corrected to the U-phase correction current value Iuc based on the U-phase temperature detection value Tu and the temperature characteristic information. In step S34, the V-phase current Iu is corrected to the V-phase corrected current value Ivc based on the V-phase temperature estimated value Tbest and the temperature characteristic information, and based on the W-phase temperature estimated value Twest and the temperature characteristic information, W The phase current Iu is corrected to the W-phase correction current value Iwc.

  Next, FIG. 10 shows a procedure of current sensor selection processing according to the present embodiment.

  In the current sensor selection process, in step S41, it is determined whether or not the absolute value of the electrical angular velocity ω is higher than the threshold velocity ωmin. This process is a process provided for the same purpose as step S31 of FIG. When an affirmative determination is made in step S41, the process proceeds to step S42, and a control phase current used for torque control is selected from the phase currents Iu, Iv, Iw. In the present embodiment, in addition to the U-phase correction current value Iuc, the V-phase correction current value Ivc is selected in advance as the control phase current. This is a situation in which the actual temperatures of the respective phase current sensors 24u, 24v, 24w are substantially equal to each other, and therefore the temperature estimation variation with respect to the U-phase temperature detection value Tu for any of the V-phase and W-phase temperature estimation values Tbest, Twest. Is based on smallness. Thereby, the processing of steps S43 and S44, which will be described later, becomes unnecessary, and the calculation load of the control device 30 can be reduced. The U and V phase correction current values Iuc and Ivc selected in step S42 are input to the two phase converter 30c.

  Incidentally, when an affirmative determination is made in step S41, the W-phase correction current value Iwc may be selected as the control phase current instead of the V-phase correction current value Ivc.

  On the other hand, if a negative determination is made in step S41, it is determined that the actual temperatures of the phase current sensors 24u, 24v, 24w are greatly different from each other, and the process proceeds to step S43. In step S43 (corresponding to “deviation calculation means”), the absolute value of the difference between the U-phase temperature increase ΔQuest and the V-phase temperature increase ΔTbest is calculated as the first deviation ΔTuv. In addition, the absolute value of the difference between the U-phase temperature rise amount ΔQuest and the W-phase temperature rise amount ΔTwest is calculated as the second deviation ΔTww.

  In a succeeding step S44, it is determined whether or not the second deviation ΔTuw is larger than the first deviation ΔTuv. This process is a process for determining which one of the V-phase correction current value Ivc and the W-phase correction current value Iwc is selected as the control phase current in addition to the U-phase correction current value Iuc. If an affirmative determination is made in step S44, the process proceeds to step S42, and the V-phase correction current value Iv is selected as the control phase current. This is because, when the first deviation ΔTuv is smaller than the second deviation ΔTuw, the V-phase temperature estimated value Tvest used for correcting the V-phase current Iv is greater than the W-phase temperature estimated value used for correcting the W-phase current Iw. This is based on the fact that the temperature estimation variation with respect to the U-phase temperature detection value Tu is smaller than Twest. Thereby, for example, in the two-phase conversion unit 30c, the calculation accuracy of the current for the remaining one phase based on the corrected current for the two phases can be improved, and the occurrence of torque fluctuation can be suppressed.

  On the other hand, if a negative determination is made in step S44, the process proceeds to step S45, where the W-phase correction current value Iwc is selected as the control phase current. This is because the W-phase temperature estimated value Twest used for correcting the W-phase current Iw is more variable in temperature estimation than the detected U-phase temperature value Tu than the V-phase temperature estimated value Tbest used for correcting the V-phase current Iv. Is based on smallness.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) When it is determined that the absolute value of the electrical angular velocity ω is equal to or less than the threshold velocity ωmin, the absolute value of the difference between the U-phase temperature increase ΔTuest and the V-phase temperature increase ΔTvest is calculated as the first deviation ΔTuv. The absolute value of the difference between the U-phase temperature rise amount ΔQuest and the W-phase temperature rise amount ΔTwest was calculated as the second deviation ΔTww. When it is determined that the second deviation ΔTuv is larger than the first deviation ΔTuv, U and V phase correction current values Iuc and Ivc are selected as control phase currents, and the second deviation ΔTuw is equal to or smaller than the first deviation ΔTuv. When it is determined that U and W phase correction current values Iuc and Iwc are selected as control phase currents. Thereby, in the configuration in which one temperature sensor 27 is provided in the control system, the detection accuracy of the current sensor corresponding to the phase where the temperature sensor is not provided can be improved. Thereby, the torque fluctuation of the motor generator 10 can be suppressed.

  (2) When it is determined that the absolute value of the electrical angular velocity ω is higher than the threshold velocity ωmin, the U and V phase correction current values Iuc and Ivc are selected as control phase currents without performing the processing of steps S43 and S44. did. Thereby, the calculation load of the control apparatus 30 can be reduced.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment. In the present embodiment, as shown in FIG. 11, torque feedback control is performed as torque control instead of current feedback control. In FIG. 11, the same processes as those in FIG. 2 are given the same reference numerals for the sake of convenience.

  The amplitude calculating unit 30k receives the command torque Trq * and calculates a normalized voltage amplitude “Vn / ω”. Here, the normalized voltage amplitude “Vn / ω” is a value obtained by dividing the amplitude command value (hereinafter, voltage amplitude Vn) of the voltage vector of the inverter 20 in the two-phase rotating coordinate system by the electrical angular velocity ω. The amplitude Vn of the voltage vector is defined as the square root of the sum of the square value of the d-axis component vd and the square value of the q-axis component of the voltage vector. The voltage amplitude Vn may be calculated using, for example, a map in which the command torque Trq * and the voltage amplitude Vn are related.

  The speed multiplier 30l calculates the voltage amplitude Vn by multiplying the normalized voltage amplitude “Vn / ω” by the electrical angular velocity ω.

  Torque estimator 30m calculates estimated torque Te of motor generator 10 based on d-axis current Idr and q-axis current Iqr output from two-phase converter 30c. Here, the estimated torque Te may be calculated using a map storing a relationship between the d-axis current Idr and the q-axis current Iqr and the estimated torque Te, or may be calculated using a model formula.

  The torque deviation calculation unit 30n calculates the torque deviation ΔT by subtracting the estimated torque Te from the command torque Trq *.

  Based on the torque deviation ΔT, the phase calculation unit 30p calculates a voltage phase δ that is the phase of the voltage vector in the dq coordinate system as an operation amount for feedback control of the estimated torque Te to the command torque Trq *. In the present embodiment, the voltage phase δ is calculated by proportional-integral control with the torque deviation ΔT as an input.

  The Vdq calculation unit 30q calculates the d and q axis command voltages Vd * and Vq * based on the voltage amplitude Vn and the voltage phase δ. The calculated d and q axis command voltages Vd * and Vq * are input to the three-phase converter 30i.

  According to the present embodiment described above, the same effect as that of the first embodiment can be obtained.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  In the first embodiment, the temperature sensor for all three-phase currents is corrected by the correction process in step S30 in FIG. 5 and then the current sensor selection process in step S40 is performed. However, the present invention is not limited to this. For example, prior to the correction process, the current sensor selection process may be performed, and the temperature correction may be performed by the correction process on the control phase current selected by the current sensor selection process.

  -You may remove the process of step S41 of previous FIG. In this case, the current sensor selection process may be started from the process of step S43.

  -In the said 1st Embodiment, as a current sensor used as the temperature detection object of a temperature sensor, not only a U-phase thing but a V-phase or a W-phase thing may be sufficient.

  In each of the above embodiments, the control system includes one temperature sensor that detects the temperature of the current sensor for one phase. Instead of this configuration, the control system may include two temperature sensors that detect the temperatures of the current sensors for two phases. Even in this case, the application of the present invention is effective when one of the two temperature sensors fails.

  The current sensor may be another current sensor such as one having a shunt resistor. The current sensor is not limited to one that is directly attached to the bus bar, and may be one that can detect the phase current in a non-contact manner with the bus bar, such as a current sensor including a Hall element. Even in this case, the application of the present invention is effective if the temperature rise of the current sensor is large due to heat generated by the flow of the phase current.

  The control amount of the motor generator is not limited to torque, and may be, for example, a rotational speed. The motor generator is not limited to a salient pole machine, and may be a non-salient pole machine such as SPMSM. The motor generator is not limited to a permanent magnet type synchronous machine, and may be a wound field type synchronous machine, for example. Furthermore, the motor generator is not limited to a synchronous machine.

  -The application object of this invention is not restricted to a vehicle.

  DESCRIPTION OF SYMBOLS 10 ... Motor generator, 24u, 24v, 24w ... U, V, W phase current sensor, 30 ... Control apparatus.

Claims (5)

A power conversion circuit (20) that is energized to apply an AC voltage to the three-phase AC rotating electric machine (10);
Current detectors (24u, 24v, 24w) that are provided corresponding to each of the three phases of the rotating electrical machine (10) and detect a phase current flowing through the rotating electrical machine;
A temperature detection unit (27) whose temperature detection target is a one-phase current detection unit among the three-phase current detection units, and is applied to a control system for a rotating electrical machine,
The current detection unit that is a temperature detection target of the temperature detection unit is a first control current detection unit (24u),
Of the three-phase current detection units, one other than the first control current detection unit is a first current detection unit, and the other is a second current detection unit,
First correction means for correcting the current detection value of the first control current detection unit to a first correction current value based on the temperature detection value of the temperature detection unit;
Each of the first control current detection unit, the first current detection unit, and the second current detection unit has its own temperature rise due to the current flowing in the phase in which it is provided, based on its current detection value A temperature rise estimation means for estimating the amount;
Reference temperature calculation means for calculating, as a reference temperature, a value obtained by subtracting the temperature increase amount of the first control current detection unit from the temperature detection value of the temperature detection unit;
A deviation between the temperature increase amount of the first control current detector and the temperature increase amount of the first current detector is defined as a first deviation, and the temperature increase amount of the first control current detector and the second current The current detection unit that detects a phase current corresponding to a smaller one of the first deviation and the second deviation, wherein a deviation from the temperature rise amount of the detection unit is a second deviation, A current detection unit other than the control current detection unit is used as a second control current detection unit, and the temperature of the second control current detection unit is increased by adding the reference temperature to the temperature increase amount of the second control current detection unit. Temperature estimation means to estimate;
Second correction means for correcting the current detection value of the second control current detection unit to a second correction current value based on the temperature of the second control current detection unit estimated by the temperature estimation unit;
Control means (30c, 30g, 30h, 30i; 30c, 30m) for controlling the control amount of the rotating electrical machine by energizing the power conversion circuit based on the first correction current value and the second correction current value. , 30p), and a control device for a rotating electrical machine. A deviation calculating means for calculating each of the first deviation and the second deviation;
The temperature estimation unit is configured to detect the phase current corresponding to the smaller one of the calculated first deviation and the second deviation when the rotational speed of the rotating electrical machine is equal to or lower than a threshold speed. When the second control current detection unit is selected and the rotational speed is higher than the threshold speed, the first calculation and the second deviation are not calculated by the deviation calculation means, and the first deviation is not performed. The control device for a rotating electrical machine according to claim 1, wherein a predetermined one of the current detection unit and the second current detection unit is selected as the second control current detection unit. The control means includes
Based on the first correction current value, the second correction current value, and the electrical angle of the rotating electric machine, the three-phase current in the three-phase fixed coordinate system of the rotating electric machine is changed to the current in the two-phase rotating coordinate system of the rotating electric machine. Two-phase conversion means (30c) for converting into
Command voltage calculation means (30g, 30h, 30i) for calculating a command voltage of the rotating electrical machine as an operation amount for feedback-controlling the current converted by the two-phase conversion means to a command current, The control device for a rotating electrical machine according to claim 1 or 2, wherein the control amount is controlled by energizing the power conversion circuit based on a voltage. The control means includes
Based on the first correction current value, the second correction current value, and the electrical angle of the rotating electric machine, the three-phase current in the three-phase fixed coordinate system of the rotating electric machine is changed to the current in the two-phase rotating coordinate system of the rotating electric machine. Two-phase conversion means (30c) for converting into
Torque estimation means (30 m) for estimating the torque of the rotating electrical machine based on the current converted by the two-phase conversion means;
Phase calculation means (30p) for calculating the phase of the voltage vector of the power conversion circuit in the two-phase rotation coordinate system as an operation amount for feedback control of the torque estimated by the torque estimation means to a command torque. 3. The control device for a rotating electrical machine according to claim 1, wherein the control amount is controlled by energizing the power conversion circuit based on a phase of the voltage vector. The power conversion circuit is a series connection body provided corresponding to each of the three phases of the rotating electrical machine, and has a series connection body of an upper arm switch (Sup to Swp) and a lower arm switch (Sun to Swn). And
In each of the three phases, the connection point between the upper arm switch and the lower arm switch and the coil (10u to 10w) of the rotating electrical machine are electrically connected via a conductive member (23u to 23w),
5. The control device for a rotating electrical machine according to claim 1, wherein the current detection unit is provided in contact with the conductive member of a phase in which the current detection unit is provided.

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