JP5724733B2 - Rotating machine control device - Google Patents

Description

  The present invention relates to a power conversion circuit including a switching element that opens and closes between a voltage applying unit having a plurality of voltage values different from each other and a terminal of a rotating machine. The present invention relates to a control device for a rotating machine that controls an amount of control of the rotating machine by turning on and off the switching element based on a detection result of a current detected by a detecting unit that detects a current flowing through the rotating machine.

  A phenomenon in which a steady error (offset error) occurs between a current detected by a current sensor and an actual value is well known. For this reason, when controlling the controlled variable of a rotary machine based on the detection value of a current sensor, there exists a possibility that controllability may fall due to the offset error of an electric current.

  Therefore, conventionally, as can be seen in Patent Document 1 below, in a configuration that generates a command voltage for each phase by performing three-phase conversion on the dq-axis voltage as the feedback operation amount of the dq-axis current, the command voltage is set to 1 It has also been proposed to correct the detection value of the current sensor by integrating over an electrical angle period and detecting an offset error based on the integration value.

JP 2006-121860 A

  However, when the above method is used, for example, when an error in detecting the electrical angle of the rotating machine occurs, the offset error is not correctly detected, and thus the detection value of the current sensor is corrected with an incorrect correction amount. It has been found by the inventors that there is a fear.

  The present invention has been made in the process of solving the above-mentioned problems, and its object is to include a switching element that opens and closes between a voltage applying means having a plurality of different voltage values and a terminal of the rotating machine. A power conversion circuit to be turned on / off based on a detection result of a current detected by a detection unit that detects a current flowing through the rotating machine, with the switching element constituting the power conversion circuit as an operation target Then, it is providing the control apparatus of the new rotary machine which controls the control amount of the said rotary machine.

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

A first invention relates to a power conversion circuit configured to include a switching element that opens and closes between a voltage applying unit having a plurality of different voltage values and a terminal of a rotating machine, and the switching that configures the power conversion circuit An apparatus for controlling a rotating machine that controls an amount of control of the rotating machine by turning on and off the switching element based on a current detection result by a detecting unit that detects current flowing through the rotating machine. , The operation state of the power conversion circuit determined by the on / off operation and expressed by a voltage vector in a fixed coordinate system as an input, and the voltage applied to each terminal or each phase of the rotating machine Applied voltage calculation means for calculating, and a period of one electrical angle period or more for each terminal or each voltage calculated by the applied voltage calculation means An integrating means for calculating an integral value over, characterized in that it comprises a feedback control means for feedback controlling the integrated value to zero.

  When the control amount of the rotating machine is controlled, if there is an offset error in the detection means, the terminal voltage of the rotating machine or the amplitude center of the phase voltage deviates from zero. For this reason, the offset error of the detection means can be compensated by feedback-controlling the integral value over one period of the voltage to zero. However, when the voltage to be integrated is calculated using the electrical angle information, the offset included in the electrical angle information is affected by the offset error compensation processing of the detection means. In this regard, in the above-described invention, the applied voltage calculation means calculates the voltage to be applied with the operation state of the power conversion circuit as an input, and therefore electrical angle information or the like is not used when calculating the voltage. For this reason, the voltage thus calculated is highly accurate without being affected by the detection error of the electrical angle. Then, the offset error of the detecting means can be suitably compensated by feedback-controlling the integrated value of this voltage to zero.

According to a second invention, in the first invention, the feedback control means includes an integration element having the integration value as an input.

  For example, when the detection value of the detection means is corrected by converting the integration value into a current value so that the integration value is zero, the integration value calculated next time by the integration means becomes zero. For this reason, in the next time, the detected value is not corrected, and an offset error occurs again. In addition, when the detection value is corrected at once so that the integral value is zero, it is directly affected by noise and the like included in the integral value. In this regard, in the above invention, by providing the feedback control means with an integral element, it is possible to eliminate a stationary error, and it becomes easy to suppress the influence of noise by setting the gain.

According to a third aspect of the present invention, in the first or second aspect of the present invention, a determination unit that determines whether or not the rotating machine is in a transient operation, and an integration of the integration unit when it is determined that the transient operation is in progress. And a prohibiting unit that prohibits the processing from being reflected in the feedback control unit.

  During transient operation, even if there is no offset error in the detection value of the detection means, the integrated value per cycle of the electrical angle does not become zero. In view of this point, in the above invention, by providing the prohibiting means, it is avoided that the integral value when the relation between the integral value and the offset error is low is reflected in the feedback control.

A fourth invention is characterized in that, in any one of the first to third inventions, the integrating means integrates a voltage applied to each terminal or each phase as a function of an electrical angle. To do.

  In the above-described invention, by integrating the voltage with the electrical angle, it is preferable to suppress a decrease in the quantification accuracy of the offset error due to the integrated value due to the fluctuation of the electrical angular velocity as compared with the case of integrating with the time. be able to.

According to a fifth invention, in any one of the first to fourth inventions, the integrating means outputs the integrated value over a period more than twice the electrical angle cycle of the rotating machine to the feedback control means. It is characterized by.

  In the above invention, by taking a long integration period, it is possible to suitably suppress the integration value from undergoing fluctuations in the electrical angular velocity on a microscopic time scale as compared with the integration value over one electrical angle cycle. . Further, when the integral multiple of the cycle for performing the integration process does not coincide with one electrical angle cycle, the value when the voltage takes various phases can be used for the integration process. Accuracy is improved.

According to a sixth invention, in any one of the first to fifth inventions, the power conversion circuit includes a switching element that selectively connects a terminal of the rotating machine to each of a positive electrode and a negative electrode of a DC voltage source, and A DC-AC conversion circuit including a diode connected in reverse parallel to a switching element, and one of the switching element connected to the positive electrode and the switching element connected to the negative electrode and the other are turned on and off respectively. When switching to a state in which one and the other are turned off and on respectively, a dead time period in which both are turned off is provided, and when the operation state is changed, the dead time is based on the current flowing through the rotating machine. A dead time correction method for reflecting the voltage applied to each terminal or each phase in the integration value in the period. And further comprising a.

  Since the voltage applied to each terminal and each phase in the dead time period depends on the current flowing through the rotating machine, the terminal voltage and the phase voltage in the period including the dead time are not uniquely determined depending on the operation state. For this reason, when switching the operation state, the calculation accuracy by the applied voltage calculation means may be reduced. In view of this point, the above invention includes a dead time correcting means.

A seventh invention provides the current flowing through the rotating machine, the torque of the rotating machine, and the rotating machine when the operation state of the power conversion circuit is temporarily set in any one of the first to sixth inventions. A predicting unit that predicts a control amount having at least one of the magnetic fluxes of the magnetic field, an operation state corresponding to the predicted control amount based on the control amount predicted by the prediction unit, and a highly evaluated operation state Is further provided with determination means for determining the operation state of the power conversion circuit, and operation means for operating the power conversion circuit so as to be in the determined operation state.

  When model predictive control is performed, the voltage vector expressing the operation state is determined each time by the determining means. For this reason, the information regarding the operation state as input information of an applied voltage calculation means can be acquired easily.

1 is a system configuration diagram according to a first embodiment. FIG. The figure which shows the voltage vector expressing the operation state of an inverter. The flowchart which shows the procedure of the model prediction process concerning the said embodiment. The flowchart which shows the procedure of the process of the voltage offset part concerning the embodiment. The figure which shows the map used for calculation of the applied voltage concerning the embodiment. The time chart which shows the effect of the embodiment. The flowchart which shows the procedure of the process of the voltage offset part concerning 2nd Embodiment. The time chart which shows the effect of the embodiment. The flowchart which shows the procedure of the process of the voltage offset part concerning 3rd Embodiment. The time chart which shows the effect of the embodiment. The flowchart which shows the procedure of the stop process of the integration process concerning 4th Embodiment. The flowchart which shows the procedure of the calculation process of the applied voltage concerning 5th Embodiment. The system block diagram concerning 6th Embodiment.

<First Embodiment>
Hereinafter, a first embodiment in which a control device for a rotating machine according to the present invention is applied to a control device for a rotating machine as an in-vehicle main machine will be described with reference to the drawings.

  FIG. 1 shows the overall configuration of a motor generator control system according to this embodiment. The motor generator 10 as an in-vehicle main machine is a three-phase permanent magnet synchronous motor. The motor generator 10 is a rotating machine (saliency pole machine) having saliency. Specifically, the motor generator 10 is an embedded magnet synchronous motor (IPMSM).

  The motor generator 10 is connected to the high voltage battery 12 and the capacitor 13 via the inverter INV. The high voltage battery 12 is a DC voltage source whose terminal voltage is, for example, 100 V or more. The inverter INV includes three sets of series connection bodies of switching elements S * p, S * n (* = u, v, w), and the connection points of these series connection bodies are the U, V, Each is connected to the W phase. In the present embodiment, insulated gate bipolar transistors (IGBTs) are used as the switching elements S * # (* = u, v, w; # = p, n). In addition, a diode D * # is connected in antiparallel to each of these.

  In the present embodiment, the following is provided as detection means for detecting the state of the motor generator 10 and the inverter INV. First, a rotation angle sensor 14 for detecting the rotation angle (electrical angle θ) of the motor generator 10 is provided. In addition, current sensors 16u, 16v, and 16w that detect phase currents (actual currents iu, iv, and iw) flowing through the U-phase, V-phase, and W-phase of motor generator 10 are provided. Furthermore, a voltage sensor 18 for detecting the input voltage (power supply voltage VDC) of the inverter INV is provided.

  The detection values of the various sensors are taken into the control device 20 constituting the low voltage system via an interface (not shown). The control device 20 generates and outputs an operation signal for operating the inverter INV based on the detection values of these various sensors. Here, the signal for operating the switching element S * # of the inverter INV is the operation signal g * #.

  The control device 20 operates the inverter INV so as to control the torque of the motor generator 10 to the required torque Tr. Specifically, the inverter INV is operated so that the command current for realizing the required torque Tr matches the current flowing through the motor generator 10. That is, in the present embodiment, the torque of the motor generator 10 becomes the final control amount. In order to control the torque, the current flowing through the motor generator 10 is directly controlled as a control current. To do. In particular, in the present embodiment, in order to control the current flowing through the motor generator 10 to a command current, the current of the motor generator 10 is predicted and predicted when the operation state of the inverter INV is temporarily set to each of a plurality of types. The temporarily set operation state is evaluated based on the current. Then, model predictive control is performed in which the highly evaluated one is adopted as the actual operation state of the inverter INV.

  Specifically, the actual currents iu, iv, iw are converted into actual currents id, iq in the rotating coordinate system by the dq converter 22. Further, the electrical angle θ detected by the rotation angle sensor 14 is input to the speed calculation unit 23, and thereby the rotation speed (electrical angular speed ω) is calculated. On the other hand, the command current setting unit 24 receives the required torque Tr and outputs command currents idr and iqr in the dq coordinate system. The command currents idr and iqr, the actual currents id and iq, and the electrical angle θ are input to the model prediction control unit 30. The model prediction control unit 30 determines a voltage vector Vi that defines the operation state of the inverter INV based on these input parameters, and inputs the voltage vector Vi to the operation unit 26. The operation unit 26 generates the operation signal g * # based on the input voltage vector Vi and outputs it to the inverter INV.

  Here, the voltage vectors expressing the operation state of the inverter INV are eight voltage vectors shown in FIG. For example, a voltage vector representing an operation state (indicated as “lower” in the drawing) in which the low-potential side switching elements Sun, Svn, Swn are turned on is the voltage vector V0, and the high-potential side switching elements Sup, A voltage vector representing an operation state (indicated as “upper” in the drawing) in which Svp and Swp are turned on is a voltage vector V7. These voltage vectors V0 and V7 are for short-circuiting all phases of the motor generator 10 and are called zero voltage vectors because the voltage applied to the motor generator 10 from the inverter INV becomes zero. On the other hand, the remaining six voltage vectors V1 to V6 are defined by an operation pattern in which switching elements that are turned on exist in both the upper arm and the lower arm, and are called effective voltage vectors. Yes. As shown in FIG. 2B, each of the voltage vectors V1, V3, and V5 corresponds to the positive side of the U phase, the V phase, and the W phase, respectively.

  Next, details of the processing of the model prediction control unit 30 will be described. In the operation state setting unit 31 shown in FIG. 1, the operation state of the inverter INV is temporarily set. Here, the voltage vectors V0 to V7 shown in FIG. 2 are temporarily set as the operation state of the inverter INV. The dq conversion unit 32 calculates the voltage vector Vdq = (vd, vq) in the dq coordinate system by performing dq conversion on the voltage vector set by the operation state setting unit 31. In order to perform such conversion, the voltage vectors V0 to V7 in the operation state setting unit 31 are, for example, “upper” as “VDC / 2” and “lower” as “−VDC / 2” in FIG. It can be expressed as above. In this case, for example, the voltage vector V0 is (−VDC / 2, −VDC / 2, −VDC / 2), and the voltage vector V1 is (VDC / 2, −VDC / 2, −VDC / 2). .

In the prediction unit 33, the current when the operation state of the inverter INV is temporarily set by the operation state setting unit 31 based on the voltage vector (vd, vq), the actual currents id, iq, and the electrical angular velocity ω. Predict id, iq. Here, basically, the voltage equations expressed by the following (c1) and (c2) are discretized from the following state equations (formulas (c3) and (c4)) obtained by solving the differential terms of the current: Predict current one step ahead.
vd = (R + pLd) id−ωLqiq (c1)
vq = ωLdid + (R + pLq) iq + ωφ (c2)
pid
= − (R / Ld) id + ω (Lq / Ld) iq + vd / Ld (c3)
piq
= −ω (Ld / Lq) id− (Rd / Lq) iq + vq / Lq−ωφ / Lq (c4)
Incidentally, in the above formulas (c1) and (c2), the resistance R, the differential operator p, the d-axis inductance Ld, the q-axis inductance Lq, and the armature flux linkage constant φ are used.

  The prediction of the current is performed for each of a plurality of operation states temporarily set by the operation state setting unit 31.

  On the other hand, the operation state setting unit 34 receives the predicted currents ide and iq predicted by the prediction unit 33 and the command currents idr and iqr, and determines the operation state of the inverter INV. Based on the operation state thus determined, the operation unit 26 generates and outputs an operation signal g * #.

  FIG. 3 shows a model prediction control processing procedure according to the present embodiment. This process is repeatedly executed at a predetermined cycle (control cycle Tc).

  In this series of processing, first, in step S10, the electrical angle θ (n) and the actual currents id (n) and iq (n) are detected, and the voltage vector V (n) determined in the previous control cycle. Is output. In subsequent step S12, the current (ide (n + 1), iqe (n + 1)) in one control cycle ahead is predicted. This is a process of predicting what will happen to the current one control cycle ahead based on the voltage vector V (n) output in step S10. Here, basically, currents ide (n + 1), iqe (n) are obtained by discretizing the model expressed by the above equations (c3) and (c4) with the control period Tc by the forward difference method. n + 1) is calculated. At this time, the actual currents id (n) and iq (n) detected in step S10 are used as the initial value of the current, and the voltage vector V (n) is used as the voltage vector on the dq axis. The one obtained by dq conversion using the electrical angle θ (n) detected in FIG.

  In subsequent steps S14 to S22, a process of predicting a current two control cycles ahead is performed for each of cases where a plurality of voltage vectors are temporarily set in the next control cycle. That is, first, in step S14, the number j that defines the voltage vector is set to “0”. In subsequent step S16, voltage vector Vj is set as voltage vector V (n + 1) in the next control cycle. In subsequent step S18, predicted currents ide (n + 2) and iqe (n + 2) are calculated in the same manner as in step S12. However, here, the predicted currents ide (n + 1) and iqe (n + 1) calculated in step S12 are used as the initial value of the current, and the voltage vector V (n + 1) is used as the voltage vector on the dq axis. What dq-transformed by the angle which added (omega) Tc to the electrical angle (theta) (n) detected in step S10 is used.

  In a succeeding step S20, it is determined whether or not the number j is “7”. This process is for determining whether or not the current prediction process has been completed for all of the voltage vectors V0 to V7 that determine the operating state of the inverter INV. If a negative determination is made in step S20, the number j is incremented in step S22, and the process returns to step S16. On the other hand, when a positive determination is made in step S20, the process proceeds to step S24.

  In step S24, a process for determining the voltage vector V (n + 1) in the next control cycle is performed. Here, a voltage vector that minimizes the evaluation function J is defined as a final voltage vector V (n + 1). In the present embodiment, an evaluation function J having a value that increases as the evaluation is lower is employed. Specifically, the evaluation function J is calculated based on the inner product value of the difference between the command current vector Idqr = (idr, iqr) and the predicted current vector Idqe = (ide, iqe). This is a method for expressing that the evaluation is lower as the value is larger in view of the fact that the deviation of each component between the command current vector Idqr and the predicted current vector Idqe can be both positive and negative values. As a result, it is possible to construct an evaluation function J in which the evaluation becomes lower as the difference between the components of the command current vector Idqr and the predicted current vector Idqe is larger.

  Here, when an affirmative determination is made in step S20, predicted currents ide (n + 2) and iqe (n + 2) are calculated for each of the voltage vectors V0 to V7. Therefore, eight values of the evaluation function J can be calculated using these eight predicted currents ide (n + 2) and iqe (n + 2). In the subsequent step S26, the voltage vectors V (n) and V (n + 1) are set to the voltage vectors V (n−1) and V (n), respectively, and the electrical angle θ (n) is the electrical angle θ (n−1). And real currents id (n) and iq (n) are assumed to be real currents id (n-1) and iq (n-1), respectively.

  In addition, when the process of step S26 is completed, this series of processes is once complete | finished.

  Incidentally, the actual currents iu, iv, and iw detected by the current sensors 16u, 16v, and 16w may cause an offset error that is deviated by a specified value (offset value) from the actual current value. In this case, the inventors have found that even when model predictive control is performed, the torque of the motor generator 10 fluctuates with an electrical angle cycle.

  Therefore, in this embodiment, the voltage of each phase is calculated from the voltage vector Vi selected each time, and the offset error is quantified by the integral value over one electrical angle period, and this is feedback-controlled to zero. That is, when an offset error occurs, the amplitude center of the phase current that should fluctuate according to the fundamental wave deviates from zero. And in the operation state setting part 34, in order to select the voltage vector Vi in order to eliminate this, the voltage applied to each phase also has an offset. Therefore, the voltage applied to each phase can be used as a quantitative value of the offset error, and the offset error can be compensated by feedback-controlling this to zero.

  In order to realize such processing, in the present embodiment, as shown in FIG. 1, the integral value calculation unit 40 receives the voltage vector Vi and the power supply voltage VDC set by the operation state setting unit 34 each time as input, The integrated values Δvu, Δvv, Δvw of the applied voltages vu, vv, vw for each phase are calculated. FIG. 4 shows a procedure of processing performed by the integral value calculation unit 40. This process is executed repeatedly in synchronization with the process shown in FIG.

  In this series of processes, first, in step S30, the current voltage vector V (n) is acquired. This process may be performed after the process of step S10 of FIG. In the subsequent step S32, the applied voltages vu (n), vv (n), and vw (n) of each phase are map-calculated from the voltage vector V (n). FIG. 5 shows this map. As shown in the figure, the map defines the relationship between each voltage vector Vi (i = 0 to 7) and the applied voltages vu, vv, and vw. Here, for example, regarding the voltage vector V1, the value of the map is indicated as follows.

  First, the line voltage Vuv between the U phase and the V phase, the line voltage Vvw between the V phase and the W phase, and the line voltage Vwu between the W phase and the U phase are expressed by the following equations.

Vuv = vu-vv = VDC-0 = VDC
Vvw = vv-vw = 0-0 = 0
Vwu = vw−vu = 0−VDC = −VDC
Here, by setting “vu + vv + vw = 0”, the value of the map shown in FIG. 5 is obtained.

  In step S34 shown in FIG. 4, the integrated value Δv * of the applied voltage v * (* = u, v, w) of each phase is calculated. This is performed by adding the product of the control cycle Tc and the current applied voltage v * (n) to the previous integrated value Δv *. In the subsequent step S36, it is determined whether or not the integration interval of the integration value Δv * is one electrical angle cycle. If it is determined that one electrical angle period has been reached, an integral value Δv * is output and initialized in step S38.

  The output integration values Δvu, Δvv, Δvw are output to the integration elements 42u, 42v, 42w shown in FIG. Then, the outputs of the integration elements 42u, 42v, and 42w are added to the actual currents iu, iv, and iw in the correction units 44u, 44v, and 44w, respectively. Thereby, the output of the integration element 42 * becomes the correction amount of the actual current i *.

  The gain Ki of the integration element 42 * is set to be smaller than a coefficient “1 / R (R: resistance value in the model of the motor generator 10) for converting the integration value Δv * into a current amount. In the case of processing for eliminating all offset errors of the actual current i * by the value Δv *, the setting is made in consideration of being easily affected by noise mixed in the integrated value Δv *.

  FIG. 6 shows the effect of this embodiment.

  As shown in the figure, according to the present embodiment, the current offset error is eliminated, and torque fluctuations are also eliminated.

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

  (1) With the voltage vector V (n) as an input, the applied voltages vu (n), vv (n), and vw (n) were map-calculated. As a result, even if there is an error in the electrical angle θ detected by the rotation angle sensor 14, the voltage actually applied to each phase can be calculated without being affected by the error, and as a result, the integral value Δv *. Can be a value obtained by quantifying the offset error of the current sensor 16 * with high accuracy.

  (2) The output of the integration element 42 * having the integration value Δv * as an input is used as the correction amount of the actual current i *. Thereby, the offset error which is a stationary error can be eliminated.

(3) Model predictive control was performed. Thereby, information (voltage vector V (n)) regarding the operation state of the inverter INV necessary for calculating the applied voltages vu (n), vv (n), and vw (n) can be easily obtained.
<Second Embodiment>
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 7 shows a procedure of processing performed by the integral value calculation unit 40 according to the present embodiment. This process is executed repeatedly in synchronization with the process shown in FIG. Of the processes shown in FIG. 7, those corresponding to the processes shown in FIG. 4 are given the same step numbers for convenience.

  In the present embodiment, in step S34a, the integrated value Δv * is integrated with the electrical angle, assuming that the applied voltage v * is a function of the electrical angle. That is, since the change amount of the electrical angle in one control cycle Tc is “ω × Tc”, a value obtained by multiplying the applied voltage v * (n) by “ω × Tc” is added to the previous integrated value Δv *. Thus, the current integration value Δv * is calculated.

  As described above, by integrating with the electrical angle, it is possible to suppress a reduction in the quantification accuracy of the offset error due to the integral value Δv * even if the electrical angular velocity ω changes. That is, as shown in FIG. 8 (a), when the electrical angular velocity ω is constant, the integration value Δv over one electrical angular cycle is obtained by integration using the control cycle Tc under the condition that the applied voltage v * is not offset. * Is zero. On the other hand, as shown in FIG. 8B, when the electrical angular velocity ω changes, integration is performed using the control cycle Tc under the condition that the applied voltage v * is not offset, the integrated value Δv * over one electrical angular cycle. Deviates from zero. On the other hand, as shown in FIG. 8 (c), even when the electrical angular velocity ω changes, integration using the electrical angle under the condition that the applied voltage v * has no offset results in one electrical angular period. The integrated value Δv * that passes is zero.

  Here, the error in the integrated value Δv * shown in FIG. 8B is due to the fact that the phase difference between the sampling timings of the applied voltage v * changes according to the electrical angular velocity ω. In other words, this is because the phase difference between the sampling timings changes before and after the change of the electrical angular velocity ω. Since the phase of the applied voltage v * is an electrical angle, in order for the applied voltage v * to be a fundamental wave, the independent variable needs to be an electrical angle. For this reason, in integration over time, an error occurs in the integrated value Δv * except when the electrical angular velocity ω does not change and the time and electrical angle are in a proportional relationship.

  According to the present embodiment described in detail above, the following effects can be obtained in addition to the above-described effects of the first embodiment.

(4) The applied voltage v * was integrated as a function of the electrical angle. Thereby, it can suppress suitably that the quantification precision of the offset error by integral value (DELTA) v * resulting from the fluctuation | variation of electrical angular velocity (omega) falls.
<Third Embodiment>
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 9 shows a procedure of processing performed by the integral value calculation unit 40 according to the present embodiment. This process is repeatedly executed at a predetermined cycle T. Of the processes shown in FIG. 9, those corresponding to the processes shown in FIG. 4 are given the same step numbers for convenience.

  In the present embodiment, the integration calculation cycle T is longer than the control cycle Tc (step S34b). In order to respond to this, in the present embodiment, the integral value Δv * is set to the integral value of the applied voltage v * over N (> 1) electrical angle cycles (step S36a). This is a setting for quantifying the average value of the voltage applied to each phase (terminal) of the motor generator 10 with higher accuracy by the integral value Δv *. That is, in order to improve the accuracy of the integral value Δv *, it is desirable to use values at various phases as the applied voltage v * used to calculate the integral value Δv *. However, as shown in FIG. 10A, if the number of samplings of the applied voltage v * used for calculating the integral value Δv * is insufficient, the phase of the applied voltage v * used for calculation is not sufficient. For this reason, an error is likely to occur in the integral value Δv *. On the other hand, as shown in FIG. 10B, the application period used to calculate the integral value Δv * is set by setting the calculation period of the integral value Δv * to N electrical angle periods (N = 4 is exemplified here). The number of samplings of the voltage v * is increased, and the phase of the applied voltage v * to be sampled has various values unless an integer multiple of the sampling period is an electrical angle period. For this reason, the error of the integral value Δv * can be reduced.

  According to the present embodiment described in detail above, the following effects can be obtained in addition to the above-described effects of the first embodiment.

(5) By increasing the integration period of the integration value Δv * to be longer than one electrical angle cycle, the number of applied voltages v * can be increased, or the applied voltage v * can be sampled at various phases. As a result, the quantification accuracy of the offset error by the integral value Δv * is improved.
<Fourth Embodiment>
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, when the operation state of the motor generator 10 becomes a transient operation state, the calculation of the integral value Δv * is stopped and the integral value Δv * is initialized. This is because, in a transient operating state, the amplitude of the voltage applied to each phase of the motor generator 10 changes, so even if no offset error occurs in the actual current i *, one electrical angular cycle This is because the integrated value of the applied voltage v * over the range does not become zero.

  FIG. 11 shows the procedure of the calculation stop processing of the integral value Δv *. This process is repeatedly executed at a predetermined cycle.

  In this series of processing, first, in step S40, the absolute value of the change amount ΔTr of the required torque Tr is greater than the specified amount ΔTth, and the absolute value of the change amount Δω of the electrical angular velocity ω is greater than the specified amount Δωth. Determine whether the logical sum is true. This process is for determining whether or not the motor generator 10 is in a transient operation. If an affirmative determination is made in step S40, the calculation process of the integral value Δv * is stopped and the integral value Δv * is initialized in step S42. As a result, the output of the integrating element 42 * during the transient operation is maintained at the output value immediately before the transition during the transient operation.

  When the process of step S42 is completed or when a negative determination is made in step S40, this series of processes is temporarily terminated.

  According to the present embodiment described in detail above, the following effects can be obtained in addition to the above-described effects of the first embodiment.

(6) When it is determined that the vehicle is in transient operation, the calculation process of the integral value Δv * is stopped. As a result, it is possible to avoid the integration value Δv * being reflected in the feedback control in a situation where the quantification accuracy of the offset error due to the integration value Δv * is reduced.
<Fifth Embodiment>
Hereinafter, a fifth embodiment will be described with reference to the drawings, focusing on differences from the first embodiment.

  In the above embodiment, the applied voltage v * is calculated as a value that is uniquely determined from the voltage vector Vi. By the way, when the switching state of the inverter INV is switched because the voltage vector V (n) is different from the voltage vector V (n−1), the switching element S * p of the upper arm and the switching element of the lower arm are switched. A dead time period DT in which both S * n and OFF are provided. In the dead time period DT, since a current flows through the diode D * # according to the polarity of the corresponding phase current, the voltage applied to the motor generator 10 depends on the phase current. For this reason, in the present embodiment, the applied voltage v * calculated by the map shown in FIG. 5 is corrected in consideration of the voltage during the dead time period.

  FIG. 12 shows the procedure of the correction process. This process is performed in synchronization with the process shown in FIG.

  In this series of processes, first, in step S50, it is determined whether or not the previous voltage vector V (n-1) and the current voltage vector V (n) are different from each other. This process is for determining whether or not the switching state of the inverter INV is changed. If an affirmative determination is made in step S50, a difference vector (U, V, W) between the current voltage vector V (n) and the previously adopted voltage vector V (n-1) is calculated in step S52. . Here, voltage vectors V (n) and V (n−1) are expressed as components of a three-phase coordinate system. Here, the value of each component may be arbitrary as long as it differs between when the upper arm is on and when the lower arm is on. However, here, for simplicity, the case where the upper arm is on is “1”, and the case where the lower arm is on is “0”. Further, the applied voltage (nu, nv, nw) in the dead time period DT is temporarily set to the current voltage vector V (n). Here, the expression method of each component of the applied voltage (nu, nv, nw) is also arbitrary, but here, for simplicity, the case where the upper arm is on is “1” and the case where the lower arm is on. “0”.

  In a succeeding step S54, it is determined whether or not the U-phase component U of the difference vector is zero. This process is for determining whether or not the switching state of the U phase is not switched by setting the voltage vector V (n). If a negative determination is made in step S54, it is determined that switching has been performed, and in step S56, it is determined whether or not the U-phase current iu is negative. This process is for determining whether or not a current flows through the diode Dup of the upper arm. Here, the current iu may be a predicted current at the output timing of the voltage vector V (n) (predicted current ide (n + 1), iqe (n + 1) in the previous control cycle). If negative, the U-phase component nu of the applied voltage during the dead time period is set to “1” (step S58). If not, the U-phase component nu is set to “0” (step S60). . This is because when the phase current is negative, current flows through the diode Dup in the dead time period DT, and when the phase current is positive, current flows through the diode Dun in the dead time period DT. In view of this.

  When the processes of steps S58 and S60 are completed or when an affirmative determination is made in step S54, the switching state of the V phase is changed by the processes of steps S62 to S68 corresponding to the processes of steps S54 to S60. And a process of setting the V-phase component nv of the applied voltage in the dead time period when changed.

  When the processes of steps S66 and S68 are completed or when an affirmative determination is made in step S62, the W-phase switching state is changed by the processes of steps S70 to S76 corresponding to the processes of steps S54 to S60. Processing for determining whether or not the change has been made, and processing for setting the W-phase component nw of the applied voltage during the dead time when changed are performed.

  When the processes in steps S74 and S76 are completed in this way, or when a negative determination is made in step S70, the process proceeds to step S78. At this time, the applied voltage (nu, nv, nw) shows a correct value as the applied voltage in the dead time period DT (however, “1” when the upper arm is on and “1” when the lower arm is on) Is simply expressed as “0”, so the absolute value is not correct). Therefore, based on this, the voltage correction amount in the dead time period DT is calculated. For example, the difference vector between the voltage vector V (n) represented by “1” and “0” and the applied voltage (nu, nv, nw) as described above is the voltage vector shown in FIG. The voltage vector is converted into an applied voltage for each phase using the map shown in FIG. 5 and the applied voltage is multiplied by “DT / Tc” as a correction amount.

  In subsequent step S80, the applied voltage v * calculated in the map in step S32 of FIG. 4 is corrected by the correction amount calculated in step S78. As a result, the applied voltage v * is a highly accurate representation of the voltage of each phase in the control cycle Tc. Therefore, in step S34 of FIG. 4, the integrated value Δv * that accurately reflects the applied voltage in the dead time period DT can be calculated.

  According to the present embodiment described in detail above, the following effects can be obtained in addition to the above-described effects of the first embodiment.

(7) Based on the current flowing through the motor generator 10, the applied voltage v * was calculated by reflecting the voltage applied in the dead time period DT. As a result, the integral value Δv * can be expressed as a current offset error with higher accuracy.
<Sixth Embodiment>
Hereinafter, the sixth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 13 shows a system configuration according to the present embodiment. In FIG. 13, the same reference numerals are given for the sake of convenience for members and processes corresponding to those shown in FIG. 1.

As illustrated, in the present embodiment, the operation target for feedback control of the integral value Δv * to zero is assumed to be the predicted currents ide and iqe. That is, the output of the integration element 42 * is converted into the d-axis correction amount Δid and the q-axis correction amount Δiq by the dq converter 60. These are used when the prediction unit 33 calculates the prediction currents ide and iqe. That is, it is added to the predicted currents ide and iqe calculated in step S12 of FIG.
<Other embodiments>
Each of the above embodiments may be modified as follows.

"Dead time correction method"
The processing is not limited to the processing exemplified in the fifth embodiment (FIG. 12). For example, when the voltage vector is changed, the integration process of the applied voltage v * (n) that is mapped based on the voltage vector V (n) is set to “v * (n) × (Tc−DT)”, “V * (n) × ω × (Tc−DT)” may be used. This may also reduce the error due to the dead time DT of the integral value Δv *.

"About integration means"
The phase voltage is not limited to be integrated over a period that is an integral multiple of the electrical angle. For example, the phase voltage in the period in which the phase voltage is positive and the absolute value of the phase voltage in the period in which the phase voltage is negative may be separately integrated and the difference between them may be calculated. In this case, even if the integration period deviates from an integral multiple of the electrical angle period, the accuracy of quantifying the offset error due to the integral value decreases due to the deviation from the integral multiple of the electrical angle by increasing the integration period. Can be suitably suppressed.

About feedback control means
The correction is not limited to the output of the integral element. For example, the sum of outputs of the proportional element and the integral element may be used as the correction amount.

  Moreover, it is not restricted to what has an integral element. For example, the integral value Δv * may be converted into a current amount and used as a correction amount. This conversion coefficient may be set to “1 / R” using the resistance value R when the motor generator 10 is modeled. In this case, if a new correction amount is not calculated by the prohibiting process by the prohibiting unit, it is desirable to continue using the previous correction amount.

About judgment means
Instead of the change amount ΔTr of the required torque Tr, it may be determined that the operation is in transient operation based on the large change amounts of the command currents idr and iqr.

“Prohibited measures”
If the integral gain Ki is made sufficiently small, a decrease in accuracy of output values of the correction units 44, 48, and 52 during transient operation can be suppressed without providing a prohibition unit.

“Temporarily set operation status”
The number of switching terminals in the switching state is not limited to “1” or less, but may be “2” or less. Moreover, all of voltage vectors V0-V7 may be sufficient.

About prediction means
It is not limited to predicting only the control amount generated by the next voltage vector V (n + 1). For example, the control amount by the operation of the inverter INV at the update timing several control cycles ahead may be sequentially predicted.

About the decision means
For example, in the first embodiment, the absolute value of the difference between the predicted current ide (n + 2) and the command current idr (n + 2) and the absolute value of the difference between the predicted current iqe (n + 2) and the command current iqr (n + 2) The weighted average processing value may be a parameter for which the degree of deviation between the predicted current and the command current is to be evaluated. In short, in order to quantify that the evaluation becomes lower as the degree of divergence is larger, it may be quantified by a parameter having a positive or negative correlation between the degree of divergence and the evaluation parameter.

"About controlled variables"
The control amount used for determining the operation of the inverter INV based on the command value and the predicted value is not limited to any of torque, magnetic flux, and current. For example, only torque or magnetic flux may be used. Further, for example, torque and current such as torque and d-axis current or torque and q-axis current may be used. Here, when the control amount is other than the current, the direct detection target by the sensor may be other than the current.

  In each of the above embodiments, the ultimate control amount of the rotating machine (the control amount that is ultimately required to be a desired amount regardless of whether or not it is a prediction target) is the torque. For example, the rotational speed may be used.

"About rotating machines"
The rotating machine is not limited to a three-phase rotating machine, and may be a four-phase or more rotating machine such as a five-phase rotating machine.

  In the above embodiment, it is assumed that the stator windings are star-connected, but the present invention is not limited to this and may be delta-connected. In this case, the terminal and phase of the rotating machine do not match. Therefore, the applied voltage calculation means may be a means for calculating the difference between the voltages applied to the two terminals of the rotating machine. However, the present invention is not limited to this, and the voltage at each terminal may be calculated, and the offset error of each phase may be specified based on the integral values thereof.

  The rotating machine is not limited to an embedded magnet synchronous machine, and may be an arbitrary synchronous machine such as a surface magnet synchronous machine or a field winding type synchronous machine. Furthermore, it is not limited to a synchronous machine, but may be an induction rotating machine such as an induction motor.

  The rotating machine is not limited to that used as the main machine of the vehicle.

"Control method of control amount"
Not only model prediction control but normal current feedback control or instantaneous current value control may be used. Even in this case, by providing the applied voltage calculation means, the degree of bias of the phase voltage can be quantified without being affected by the error of the electrical angle θ, etc., so that the actual currents iu, iv, iw An offset error can be detected with high accuracy.

"others"
The DC voltage source is not limited to the high voltage battery 12 and may be, for example, an output terminal of a converter that boosts the voltage of the high voltage battery 12.

  As a power conversion circuit comprising a switching element that opens and closes between a voltage applying means having a plurality of voltage values different from each other and a terminal of the rotating machine, the terminal of the rotating machine is connected to the positive and negative terminals of the DC voltage source. The present invention is not limited to a DC / AC conversion circuit (inverter INV) including switching elements selectively connected to each. For example, it may be provided with a switching element that selectively opens and closes between a voltage applying unit that applies three or more different voltages to each phase of the multiphase rotating machine and a terminal of the rotating machine. . An example of a power conversion circuit for applying three or more different voltages to a terminal of a rotating machine is exemplified in Japanese Patent Application Laid-Open No. 2006-174697.

  DESCRIPTION OF SYMBOLS 10 ... Motor generator, 20 ... Control apparatus, 40 ... Integration value calculation part, 42u, 42v, 42w ... Integration element, 44u, 44v, 44w ... Correction part.

Claims (8)

For a power conversion circuit configured to include a switching element that opens and closes between a voltage application unit having a plurality of voltage values different from each other and a terminal of the rotating machine, the switching element constituting the power conversion circuit is an operation target, In a control device for a rotating machine that controls a control amount of the rotating machine by turning on and off the switching element based on a detection result of a current by a detecting unit that detects a current flowing through the rotating machine.
A voltage vector representing the operation state of the power converter circuit as the input voltage vector of a fixed coordinate system that Sadama by the on-off operation, the detection value of the rotation angle sensor for detecting a rotational angle of the rotating machine Applied voltage calculation means for calculating a voltage applied to each terminal or each phase using a pre-calculated relationship between a voltage applied to each terminal or each phase of the rotating machine and the voltage vector without using When,
Integrating means for calculating an integral value over a period of one electrical angle period or more for each voltage of each terminal or each phase calculated by the applied voltage calculating means;
Feedback control means for feedback-controlling the integral value to zero;
A control device for a rotating machine. Based on the detection result of the current by the detection means, a control amount having at least one of the current flowing through the rotating machine, the torque of the rotating machine, and the magnetic flux of the rotating machine when the voltage vector is temporarily set. Prediction means to predict;
A determination unit that evaluates the voltage vector corresponding to the predicted control amount based on the control amount predicted by the prediction unit, and determines the voltage vector having a high evaluation as an operation state of the power conversion circuit;
Operating means for operating the power conversion circuit so as to be in the determined operation state,
2. The control apparatus for a rotating machine according to claim 1 , wherein the feedback control unit corrects the detection result of the current by the detection unit with a correction amount that feedback-controls the integral value to zero . The control apparatus for a rotating machine according to claim 1 or 2 , wherein the feedback control means includes an integration element that receives the integration value as an input. Determining means for determining whether or not the rotating machine is in a transient operation;
4. The apparatus according to claim 1, further comprising a prohibiting unit that prohibits the integration process of the integrating unit from being reflected in the feedback control unit when it is determined that the operation is in the transient operation . The control device for a rotating machine according to Item 1 . It said integrating means, the control device for a rotary machine according to any one of claims 1 to 4, characterized in that the voltage applied to each terminal or each phase is to integration as a function of the electrical angle . Said integration means, rotary machine according to any one of claims 1 to 5, characterized in that outputs the integral value over a period of more than 2 times the electrical angle period of the rotating machine to the feedback control means Control device. The power conversion circuit is a DC / AC conversion circuit including a switching element that selectively connects a terminal of the rotating machine to each of a positive electrode and a negative electrode of a DC voltage source and a diode connected in reverse parallel to the switching element,
When switching from the state where either one of the switching element connected to the positive electrode and the switching element connected to the negative electrode and the other are turned on and off to the state where one and the other are turned off and on, respectively, There is a dead time period to turn off,
When the operation state is changed, the apparatus further includes a dead time correction unit that reflects a voltage applied to each terminal or each phase in the dead time period based on a current flowing through the rotating machine in the integral value. The control device for a rotating machine according to any one of claims 1 to 6 . Predicting means for predicting a control amount having at least one of a current flowing through the rotating machine, a torque of the rotating machine, and a magnetic flux of the rotating machine when the voltage vector is temporarily set;
Based on the control amount predicted by said prediction means, and determining means for evaluating the voltage vector corresponding to the control amount of the prediction to determine a high rating the voltage vector as the operation state of the power conversion circuit,
The rotating machine control device according to any one of claims 1 to 7 , further comprising operation means for operating the power conversion circuit so as to be in the determined operation state.

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