JP5737163B2 - Rotating machine control device - Google Patents

Description

  The present invention relates to a DC / AC conversion circuit including a switching element that connects a terminal of a rotating machine to each of a positive electrode and a negative electrode of a DC voltage source, and a rectifier that is connected in reverse parallel to the switching element. The control device of the rotating machine controls the control amount having at least one of the current flowing through the rotating machine, the torque of the rotating machine, and the linkage flux of the rotating machine.

  As this type of control device, a device that calculates a command voltage as an operation amount for feedback control of an actual current of a motor to a command current and operates an inverter based on the command voltage is well known. Here, in a so-called locked state in which the motor is stopped or in a very low speed state, the state in which the command current maximizes the current of a specific leg continues. For this reason, an inverter is operated so that the state which makes the electric current of a specific leg the maximum is continued by feedback control. In this case, the amount of heat generated by the leg may become excessively large.

  Therefore, conventionally, for example, as shown in Patent Document 1, it has been proposed to change the command current in the locked state. Thereby, since the leg through which the maximum current flows is changed, it is possible to alleviate the situation where heat is concentrated on a specific leg.

JP 2007-267512 A

  However, in the above case, it is necessary to design means for changing the setting of the command current. Moreover, changing the command current means increasing the reactive current, leading to an increase in loss.

  The present invention has been made in the process of solving the above-mentioned problems, and its object is to connect a switching element that connects a terminal of a rotating machine to each of a positive electrode and a negative electrode of a DC voltage source, and an anti-parallel connection to the switching element. A DC / AC conversion circuit including the rectifying means, by operating the switching element of the DC / AC conversion circuit, so that at least one of the current flowing through the rotating machine, the torque of the rotating machine, and the linkage flux of the rotating machine It is an object of the present invention to provide a new control device for a rotating machine that controls a control amount having two.

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

In the configuration 1, a switching element for connecting the terminals of the rotating machine, each of the positive electrode and the negative electrode of the DC voltage source, the DC-AC converter circuit and a rectifying means connected in antiparallel to the switching element, the DC-AC converter In the control device for a rotating machine that controls the control amount having at least one of the current flowing through the rotating machine, the torque of the rotating machine, and the linkage flux of the rotating machine by operating the switching element of the circuit, Prediction means for temporarily setting a switching mode indicating whether each of the switching elements is in an on state or an off state, and predicting the control amount according to the temporarily set switching mode, and a prediction result by the prediction means And determining means for determining a switching mode used for actual operation of the DC-AC converter circuit, and Operating means for operating the switching element so as to be in the switching mode determined in response to the switching mode, and the determining means is configured to determine the switching mode used for the actual operation in reverse parallel to the switching element and the switching element. It is characterized by comprising priority means for giving priority to the switching mode for reducing the difference between the calorific values of the flow restricting elements including the rectifying means connected thereto.

  When model predictive control is used as described above, the decision means is only restricted based on the prediction result of the prediction means when determining the switching mode, so there are significant restrictions on the selection of the switching mode as in current feedback control. There is no. For this reason, the process which gives priority to the switching mode which reduces the difference in the said emitted-heat amount is possible. In the above invention, in view of this point, by providing the priority means, it is possible to preferably alleviate the situation where heat is concentrated on the flow regulation element of a specific leg even in the locked state.

In the configuration 2, in the configuration 1, the priority means, to those corresponding to the reactive voltage vector again through those corresponding to the effective voltage vectors from those switching modes used for the actual operation corresponds to the reactive voltage vector Leg equalization means for operating a switching mode to control so that the number of switching states of the legs constituting the DC-AC converter circuit is the same during the period until the time is reached.

  In the above invention, it is possible to reduce the variation in the calorific value between the legs due to the switching of the switching state during the period until the reactive voltage vector again corresponds.

In the configuration 3, in the configuration 2, the leg equalizing means is characterized by an odd number of said switching number.

  In the above invention, as the switching mode corresponding to the reactive voltage vector, the switching mode in which all the switching elements in the upper arm are turned on and the switching mode in which all the switching elements in the lower arm are turned on are alternately selected. Become. Here, in the locked state, since the ratio of the period in which the switching mode corresponding to the reactive voltage vector is employed increases, this also favors variation in the amount of heat generated due to conduction loss between the upper arm and the lower arm. Reduced to

In the configuration 4, the structure 3, wherein the rotating machine is a three-phase rotary machine, said determining means, using the conditions the actual operation of the number of legs switching of the switching state is made is 1 or less The leg equalization means, the switching mode used for the actual operation corresponds to the invalid voltage vector again from the one corresponding to the valid voltage vector to the invalid voltage vector. In the period until the operation is performed, two different switching modes corresponding to the effective voltage vector are determined as the switching modes used in the actual operation.

  In the above invention, as the switching mode corresponding to the reactive voltage vector, the switching mode in which all the switching elements in the upper arm are turned on and the switching mode in which all the switching elements in the lower arm are turned on are alternately selected. Become. Here, in the locked state, since the ratio of the period in which the switching mode corresponding to the reactive voltage vector is employed increases, this also favors variation in the amount of heat generated due to conduction loss between the upper arm and the lower arm. Reduced to

In Configuration 5, the structure 1, the priority means, for each leg of the DC-AC conversion circuit, the switching frequency equalizing means for operating the switching mode to control the switching frequency of the switching state to a predetermined value in a predetermined period It is characterized by providing.

  In the said invention, the dispersion | variation between legs about the emitted-heat amount resulting from switching of a switching state can be reduced.

In Configuration 6, in the configuration 3, the switching frequency equalizing means, switching the mode used for leg switching frequency of the switching state becomes a specified value to the switching mode the actual operation for switching the switching state in the predetermined period It is forbidden to be determined.

In the configuration 7, in the configuration 1, the priority means, for those current flowing out of the legs constituting the DC-AC converter is maximum, the DC and the flow control element connected to the positive electrode of the DC voltage source Intra-leg equalization means for operating a switching mode so as to reduce and control the difference in the amount of heat generated from the flow regulating element connected to the negative electrode of the voltage source.

  In the above invention, by providing the in-leg equalizing means, it is possible to avoid a situation in which the heat generation amount of the flow restriction element of any one arm of any leg becomes excessively larger than the heat generation amount of the flow restriction element of the other arm. can do.

In the configuration 8, in the structure 7, the determining means, and by increasing the difference evaluation of small switching mode of the predicted controlled variables by the prediction unit and the command value, wherein a high switching mode evaluation fact Switching mode used for the operation of the above, the in-leg equalization means, when the evaluation of the switching mode corresponding to the reactive voltage vector is higher than the evaluation of the switching mode corresponding to the effective voltage vector, the lower side A reactive voltage vector period adjusting means for performing the reduction control depending on whether a switching mode in which all the switching elements of the arm are turned on or a switching mode in which all of the switching elements of the upper arm are turned on is provided. Features.

  Regardless of which one of the switching mode in which all of the lower-arm switching elements are turned on and the switching mode in which all of the upper-arm switching elements are turned on, the behavior of the control amount may be regarded as the same. For this reason, the difference in the calorific value can be reduced without degrading the controllability of the control amount by setting which of these to be adopted as the operation amount of the reduction control. Moreover, since the proportion of the reactive voltage vector period increases in the locked state, it is possible to select which distribution regulating element generates heat during most of the controlled period only by the above operation. .

In the configuration 9, in the configuration 8, the reactive voltage vector period adjustment means is that all the switching elements of the period and the upper arm in which all turned on switching elements of the lower arm is ON period In order to control the ratio to the target value, the switching mode in which all the lower-arm switching elements are turned on or the switching mode in which all the upper-arm switching elements are turned on is determined. It is characterized by.

In the configuration 10, in the configuration 8, the reactive voltage vector period adjustment means for the leg of the current flows up, the energization period of the flow control element connected to the positive electrode of the DC voltage source of the DC voltage source A switching mode in which all of the switching elements in the lower arm are turned on and a switching in which all of the switching elements in the upper arm are turned on in order to control the ratio with the energization period of the flow regulating element connected to the negative electrode to a target value. It is characterized in that a decision as to which mode is to be made is performed.

  The amount of heat generated by the leg with the largest flowing current tends to be the leg with the largest amount of heat generated. Therefore, depending on the ratio of the energizing period of the flow regulating element connected to the positive electrode of the DC voltage source and the energizing period of the flow regulating element connected to the negative electrode of the DC voltage source, the heat generation of a specific distribution regulating element The amount can be excessive. In the said invention, it was set as the said setting in view of this point.

In the configuration 11, in the configuration 8, the reactive voltage vector period adjustment means comprises acquisition means for acquiring information about the integrated value of the heating value for each of said flow control element, all on the switching elements of the lower arm Use of the switching mode in which the acquired integrated value of the calorific value reaches a predetermined value among the pair of switching modes of the switching mode in which the switching element of the upper arm and all of the switching elements of the upper arm are turned on Is prohibited.

In the configuration 12, in the structure 7, the leg in the equalizing means comprises acquisition means for acquiring information about the integrated value of the heating value for each of said flow control element, the integrated value of the acquired amount of heat given It is characterized by comprising prohibiting means for prohibiting the use of a switching mode for energizing those that have reached the value.

  In the said invention, the situation where the temperature of a specific distribution control element becomes high excessively can be avoided suitably by providing a prohibition means.

1 is a system configuration diagram according to a first embodiment. FIG. The figure which shows the operation area | region of the motor generator concerning the embodiment. The figure which shows switching mode. The flowchart which shows the process sequence of the model prediction control concerning the embodiment. The flowchart which shows the partial detailed procedure of the said model prediction control. The figure explaining the principle of the embodiment. The figure which shows the effect of the same embodiment. The flowchart which shows the partial detailed procedure of the model prediction control concerning 2nd Embodiment. The figure which shows the effect of the same embodiment. The figure which shows the effect of the same embodiment. The figure which shows the effect of the same embodiment. The figure which shows the effect of the same embodiment. The figure which shows the effect of the same embodiment. The figure which shows the effect of the same embodiment. The figure which shows the effect of the same embodiment. The flowchart which shows the partial detailed procedure of the model prediction control concerning 3rd Embodiment. The flowchart which shows the partial detailed procedure of the model prediction control concerning 4th Embodiment. The flowchart which shows the partial detailed procedure of the model prediction control concerning 5th Embodiment. The flowchart which shows the partial detailed procedure of the model prediction control concerning 6th Embodiment. The flowchart which shows the partial detailed procedure of the model prediction control concerning 7th Embodiment. The flowchart which shows the partial detailed procedure of the model prediction control concerning 8th Embodiment. The flowchart which shows the partial detailed procedure of the model prediction control concerning 9th Embodiment.

<First Embodiment>
Hereinafter, a first embodiment of a control device for a rotating machine according to the present invention 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 is a three-phase permanent magnet synchronous motor. Specifically, the motor generator 10 is a surface magnet synchronous motor (SPMSM).

  The motor generator 10 is connected to the high voltage battery 12 via the inverter INV. 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 U, V, Each is connected to the W phase. As these switching elements S ¥ # (¥ = u, v, w; # = p, n), an insulated gate bipolar transistor (IGBT) is used in the present embodiment. 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. Further, a current sensor 16 that detects currents iu, iv, and iw flowing through the phases of the motor generator 10 is 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 T *. Here, the required torque T * is limited to a region equal to or less than the limit torque Tth as shown in FIG. Limiting torque Tth is determined according to the heat generation limit of switching element S ¥ # and diode D ¥ #. In FIG. 2, when the electrical angular velocity ω is larger than the threshold velocity ωth, the torque decreases. This is because the motor generator 10 torque and the electric power when the modulation rate of the output voltage of the inverter INV is the maximum. It is a curve which shows the relationship with angular velocity.

  Control device 20 operates inverter INV so that the command current for realizing required torque T * matches the current flowing through 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 the command current, the current of the motor generator 10 when the switching mode is temporarily set to each of a plurality of modes is predicted, and the actual switching of the inverter INV is predicted. Perform model predictive control to determine the mode.

  The switching mode indicates whether each of the switching elements S ¥ # constituting the inverter INV is on or off, and includes eight switching modes 0 to 7 shown in FIG. . For example, the switching mode in which all of the low potential side switching elements Sun, Svn, Swn are in the on state is the switching mode 0, and the switching mode in which all of the high potential side switching elements Sup, Svp, Swp are in the on state. This is switching mode 7. In these switching modes 0 and 7, all phases of the motor generator 10 are short-circuited, and the voltage applied to the motor generator 10 from the inverter INV becomes zero. Therefore, the output voltage vector of the inverter INV is set to an invalid voltage. It is a vector. On the other hand, the remaining six switching modes 1 to 6 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 the output voltage vector of the inverter INV is expressed as follows. This is an effective voltage vector.

  FIG. 3B shows voltage vectors V0 to V7 corresponding to the switching modes 0 to 7, respectively. Voltage vectors V0 to V7 indicate output voltage vectors of the inverter INV in each of the switching modes 0 to 7. As shown in the figure, voltage vectors V1, V3, and V5 corresponding to the switching modes 1, 3, and 5 correspond to the positive sides of the U phase, the V phase, and the W phase, respectively.

  Here, the model predictive control will be described in detail.

  The phase currents iu, iv, iw detected by the current sensor 16 shown in FIG. 1 are converted into actual currents id, iq in the rotating coordinate system by the dq converter 22. Further, the rotation angle (electrical angle θ) detected by the rotation angle sensor 14 is input to the speed calculation unit 24, and thereby the rotation speed (electrical angular speed ω) is calculated. On the other hand, the command current setting unit 26 receives the requested torque T * and outputs the command currents id * and iq * in the dq coordinate system. These command currents id *, iq *, actual currents id, iq, electrical angular velocity ω, and electrical angle θ are input to the model prediction control unit 30. The model prediction control unit 30 determines the switching mode of the inverter INV based on these input parameters and outputs it to the operation unit 28. The operation unit 28 generates the operation signal g ¥ # based on the input switching mode and outputs it to the inverter INV.

  Next, details of the processing of the model prediction control unit 30 will be described. The mode setting unit 31 temporarily sets the switching mode of the inverter INV shown in FIG. This process is actually a process of temporarily setting a voltage vector corresponding to the switching mode. The dq conversion unit 32 calculates the voltage vector Vdq = (vd, vq) of the dq coordinate system by performing dq conversion on the voltage vector temporarily set by the mode setting unit 31. In order to perform such conversion, the voltage vector V0 to V7 temporarily set in the mode setting unit 31 is set to, for example, “VDC / 2” when the upper arm is on and “−VDC” when the lower arm is on. / 2 ”. 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 id when the switching mode of the inverter INV is temporarily set by the mode setting unit 31 based on the voltage vector (vd, vq), the actual current id, iq, and the electrical angular velocity ω. , Iq is predicted. The prediction of the current is performed for each of a plurality of switching modes temporarily set by the mode setting unit 31 based on model expressions expressed by the following expressions (c1) and (c2).
vd = R · id + Ld · (did / dt) −ω · Lq · iq (c1)
vq = R · iq + Lq · (diq / dt) + ω · Ld · id + ω · φ (c2)
Here, the resistance R, the armature flux linkage constant φ, the d-axis inductance Ld, and the q-axis inductance Lq were used.

  On the other hand, the mode determination unit 34 receives the predicted currents ide and iq predicted by the prediction unit 33 and the command currents id * and iq *, and determines the switching mode of the inverter INV. Based on the switching mode thus determined, the operation unit 28 generates and outputs an operation signal g ¥ #.

  FIG. 4 shows a processing procedure of model predictive control according to the present embodiment. This process is repeatedly executed in a cycle (control cycle Tc) having a predetermined length.

  In this series of processing, first, in step S10, the electrical angle θ (n), the actual currents id (n), iq (n) are detected, and the voltage vector V (n) determined in the previous control cycle is output. . That is, the switching mode of the inverter INV is updated to the switching mode determined in the previous control cycle (the switching mode corresponding to the voltage vector V (n)).

In subsequent step S12, an average voltage vector (vda (n), vqa (n)), which is an average output voltage vector of the inverter INV, is calculated. This is because the following formulas (c3) and (c4) are obtained by substituting the actual currents id (n) and iq (n) into the formulas (c1) and (c2) excluding the term of the differential value of the current. Can be calculated.
vda = R · id−ω · Lqs · iq (c3)
vqa = R · iq + ω · Lds · id + ω · φ (c4)
In subsequent step S14, 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. This decomposes the voltage vectors (vd, vq) of the above equations (c1) and (c2) into an average voltage vector (vda, vqa) and an instantaneous voltage vector (vd-vda, vq-vqa), and instantaneously This is performed using the following equations (c5) and (c6) in which the voltage vector (vd−vda, vq−vqa) and the differential term of the current in the above equations (c1) and (c2) are equal. it can.
vd−vda = Ld · (did / dt) (c5)
vq−vqa = Lq · (diq / dt) (c6)
Specifically, it can be performed by the following formulas (c7) and (c8) obtained by discretizing the above formulas (c5) and (c6) with the control cycle Tc.
ide (n + 1)
= Tc · {vd (n) −vda (n)} / Ld + id (n) (c7)
iq (n + 1)
= Tc · {vq (n) −vqa (n)} / Lq + iq (n) (c8)
Incidentally, the voltage vector (vd (n), vq (n)) here uses a conversion matrix based on the electrical angle θ (n) detected in step S10 from the voltage vector V (n) output in step S10. Thus, the voltage component on the dq axis is calculated.

  In subsequent steps S16 to S22, a process of predicting a current two control cycles ahead is performed for each of cases where the switching mode (voltage vector V (n + 1)) in the next control cycle is temporarily set in a plurality of ways. That is, first, in step S16, the voltage vector V (n + 1) is temporarily set. This process will be described in detail later. In the subsequent step S18, the average voltage vector (vda (n + 1) is used in the same manner as in step S12 using the predicted currents ide (n + 1) and iqe (n + 1) instead of the actual currents id (n) and iq (n). ), Vqa (n + 1)). Further, in step S20, the predicted currents ide (n + 2) and iqe (n + 2) ahead of two control cycles are calculated in the same manner as in step S14. Here, the predicted currents ide (n + 1) and iqe (n + 1) are used instead of the actual currents id (n) and iq (n), and the instantaneous voltage vectors (vd (n + 1) −vda (n + 1), vq (n + 1) are used. ) -Vqa (n + 1)). The voltage vectors (vd (n + 1), vq (n + 1)) here are rotation angles obtained by adding “ωTc” to the electrical angle θ (n) of the voltage vector V (n + 1) temporarily set in step S16. The voltage component on the dq axis is calculated by conversion using a conversion matrix.

  In step S22, it is determined whether or not the calculation of the predicted currents ide (n + 2) and iqe (n + 2) has been completed for all the switching modes (voltage vectors) that are temporary setting candidates. If a negative determination is made in step S22, the process returns to step S16. On the other hand, when a positive determination is made in step S22, the process proceeds to step S24.

  In step S24, processing for determining the switching mode (voltage vector V (n + 1)) in the next control cycle is performed. Here, the highest switching mode evaluated by the evaluation function J is defined as the final switching mode (voltage vector V (n + 1)). In the present embodiment, the switching mode is evaluated using the evaluation function J, which is evaluated as the difference between the components of the command current vector and the predicted current vector is larger. In detail, as the evaluation function J, a function whose value becomes larger as the evaluation is lower is adopted. Specifically, the evaluation function J is calculated based on the square of the norm (inner product value) of the difference (error vector edq) between the command current vector (id *, iq *) and the predicted current vector (ide, iqe). To do. 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 and the predicted current vector can be both positive and negative values.

  In the subsequent step S26, the parameter n specifying the voltage vector, the current, and the electrical angle sampling number is decreased and corrected by "1", thereby updating the parameter n and ending this series of processes once.

  FIG. 5 shows details of the processing in step S16. This process constitutes leg equalization means.

  In this series of processes, first, in step S30, a temporarily set switching mode is selected from modes 0 to 7. In the subsequent step S32, it is determined whether the logical product of the pair of conditions is true for the condition that the absolute value of the electrical angular velocity ω is equal to or less than the specified value and the condition that the required torque T * is not zero. To do. This process is for determining whether or not the situation in which the current flowing through the specific switching element continues increases when no measures are taken. Here, the specified value is set to a value for determining whether the motor generator 10 is stopped or rotating at an extremely low speed.

  When an affirmative determination is made in step S32, it is determined in step S34 whether or not the voltage vector V (n) corresponding to the current switching mode is the invalid voltage vectors V0 and V7. If it is determined that they are not invalid voltage vectors V0 and V7 (effective voltage vectors V1 to V6), in step S36, by voltage vector V (n + 1) corresponding to the switching mode temporarily set in step S30, In the phase in which the switching state is switched and the switching state is switched, it is determined whether or not the switching state has already been switched. Here, whether or not the switching state has already been switched is determined by whether or not the flag F ¥ is “1”. The flag F ¥ indicates a switching history of switching states. For example, when the switching state of the U phase is switched, Fu = 1.

  If an affirmative determination is made in step S36, the switching mode that has been studied through the processing of steps S34 and S36 is removed from the temporary setting target, and the process returns to step S30 to change the temporarily set switching mode.

  On the other hand, when a negative determination is made in step S36, the process proceeds to step S38. In step S38, the switching mode that has been studied through the processing of steps S34 to S36 is set as the evaluation target of the evaluation function J. When the switching state is switched by this, the flag of the phase in which the switching state is switched. Update F ¥.

  On the other hand, if a negative determination is made in step S32 or an affirmative determination is made in step S34, the flags Fu, Fv, and Fw are set to zero. When the processes in steps S38 and S40 are completed, the process in step S16 in FIG. 4 is temporarily terminated.

  Here, the technical significance of the processing of FIG. 5 will be described.

  When attempting to output torque with the motor generator 10 at a very low rotational speed, a situation in which the current of a specific phase becomes maximum can continue. For example, when the electric angle θ = −90 ° is stopped, a current (id * = 0, iq *> 0) is supplied for the minimum current / maximum torque control. This is the case. In this example, the command current iq * is a current in the U-phase positive direction. For this reason, the state where the current iu of a specific phase (here, the U phase) becomes maximum as shown in FIG.

  In this case, for example, if no restriction is provided for the temporary setting of the switching mode, a situation in which the switching mode 0 and the switching mode 1 are alternately selected may occur. In this case, as shown in FIG. 6B, in the switching mode 1, the current flows from the switching element Sup to the switching elements Svn and Swn, and the current flowing through the switching element Sup becomes the maximum. On the other hand, as shown in FIG. 6C, in the switching mode 0, current flows out from the diode Dun to the switching elements Svn and Swn, and the current flowing through the diode Dun becomes maximum.

  As described above, since the U-phase current is the maximum, the conduction loss between the switching element Sup and the diode Dun increases, and the loss (switching loss) associated with switching of the switching state only in the switching element Sup. As a result, the amount of heat generated by the switching element Sup tends to be excessively large.

  On the other hand, in the case of the present application, the number of switching of the switching state of each leg until the voltage vector corresponding to the switching mode changes from the invalid voltage vector to the invalid voltage vector through the valid voltage vector is limited to one. And switching mode 7 are adopted alternately. For this reason, FIG. 7A illustrates a case in which a current (id * = 0, iq *> 0) for the minimum current / maximum torque control is supplied when stopping at the electrical angle θ = −90 °. Thus, first, by equalizing the switching frequency, it is possible to avoid a situation in which the switching loss of a specific phase becomes excessively large. Note that the conventional example shown in FIG. 7B is a case where model predictive control is performed without providing restrictions on a switching mode to be temporarily set.

  Second, it is possible to avoid a situation in which the conduction loss of the switching element S ¥ # and the diode D ¥ # of a specific arm of a specific phase becomes excessively large. FIG. 7A shows an example in which the conduction loss of the diode Dun can be reduced. In particular, in the low rotation speed region of the motor generator 10, this ratio is remarkable because the ratio of the period in which the switching modes 0 and 7 corresponding to the reactive voltage vector are employed increases. That is, when only switching modes 0 and 1 are employed alternately, the proportion of the period during which switching mode 0 is employed increases, so that the conduction loss of diode Dun may be excessively increased. On the other hand, such a situation can be avoided by alternately adopting the switching mode 0 and the switching mode 7.

In the low rotation speed region of motor generator 10, the ratio of the period in which switching modes 0 and 7 corresponding to the reactive voltage vector are increased is related to the setting shown in FIG. That is, until the threshold speed ωth (> 0) is reached, the allowable maximum torque is a constant value (limit torque Tth), and therefore, the modulation rate of the inverter INV is low in a region where the rotational speed is low. In particular, in the present embodiment, the voltage vector (vd, vq) when the current differential term and the electrical angular velocity ω are zero and the current is a value corresponding to the limit torque Tth in the above formulas (c1) and (c2). The norm of = (R · id, R · iq) is equal to or less than “1/10” of the norm having a modulation rate of “1”. For this reason, when both are used compared with what uses only one of a pair of invalid voltage vectors V0 and V7, conduction | electrical_connection loss can fully 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.

  FIG. 8 shows details of the processing in step S16 according to the present embodiment. This process constitutes leg equalization means. In FIG. 8, the same step numbers are assigned for convenience to those corresponding to the processing shown in FIG.

  In the present embodiment, in step S30a, the temporarily set switching mode is set such that the number of legs (number of legs) of the motor generator 10 whose switching state is switched from the current switching mode is “1” or less. Specifically, when the voltage vector V (n) corresponding to the current switching mode is the effective voltage vector Vi (i = 1 to 6), the voltage vector V (n + 1) corresponding to the temporarily set switching mode is set to the voltage The vectors are Vi-1, Vi, Vi + 1 (i: mod 6) or the reactive voltage vector. However, regarding the selection of the reactive voltage vector, if “V (n) = V2k (k = 1 to 3)”, the reactive voltage vector V7 is selected, and if “V (n) = V2k−1”. The reactive voltage vector V0 is selected. In the figure, for the case of “V (n) = V1,” four voltage vectors that can be temporarily set as the voltage vector V (n + 1) are shown. In addition, when the voltage vector V (n) corresponding to the current switching mode is the invalid voltage vector V0, the voltage vector V (n + 1) corresponding to the temporarily set switching mode is changed to the odd voltage vectors V1, V3, V5. Alternatively, the reactive voltage vector V0 is used. Further, when the voltage vector V (n) corresponding to the current switching mode is the invalid voltage vector V7, the voltage vector V (n + 1) corresponding to the temporarily set switching mode is changed to the even voltage vectors V2, V4, V6. Alternatively, the reactive voltage vector V7 is used.

  And while limiting the number of switching legs of the switching state, the switching mode corresponds to the invalid voltage vector through the one corresponding to the invalid voltage vector from the one corresponding to the invalid voltage vector as in the first embodiment. In order to make the number of switching of the switching state 1 in each leg, the following processing is performed.

  That is, when an affirmative determination is made in step S32, in step S46, the voltage vector V (n) corresponding to the current switching mode is an effective voltage vector and the voltage vector V (n− corresponding to the previous switching mode). It is determined whether or not 1) is the invalid voltage vectors V0 and V7. If an affirmative determination is made in step S46, the voltage vector V (n + 1) corresponding to the temporarily set switching mode is limited to the effective voltage vectors V1 to V6 in step S48.

  On the other hand, when a negative determination is made in step S46, in step S50, both voltage vectors V (n) and V (n-1) corresponding to the current switching mode and the previous switching mode are effective voltages. It is determined whether the vectors V1 to V6 are different from each other. If an affirmative determination is made in step S50, the voltage vector V (n + 1) corresponding to the temporarily set switching mode is set to the current voltage vector V (n) or the invalid voltage vectors V0 and V7 in step S52. .

  If a negative determination is made in step S50, or if the processing in steps S48 and S52 is completed, this series of processing is temporarily terminated.

  FIG. 9 shows the effect of this embodiment.

  As shown in the figure, also in this embodiment, the switching frequency of the switching state and the conduction time for each arm of each leg can be equalized.

  FIGS. 10 and 11 show the effects when the electrical angle θ is “−90 °” and when the rotation is stopped at other rotation angles. As shown in the drawing, regardless of the stop position, it is possible to obtain a dispersion effect of energization time (FIG. 10) and a dispersion effect of switching frequency (FIG. 11).

FIGS. 12 to 15 show examples of switching transitions in the case where the minimum current / maximum torque control is performed when the electrical angle θ is stopped at “−90”, “7.5”, “15”, and “0”. Indicates.
<Third Embodiment>
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, the switching frequency is equalized by counting the switching frequency of the switching state and prohibiting the switching of the phase when the switching frequency reaches the threshold value Cth.

  FIG. 16 shows details of the processing in step S16 according to the present embodiment. This process constitutes a switching frequency equalizing means. Note that, in FIG. 16, the same step numbers are attached for convenience to those corresponding to the processing shown in FIG.

  In this embodiment, when an affirmative determination is made in step S32, in step S54, a counter C ¥ that counts the number of switching of the switching state with respect to the phase (leg) in which the switching state is switched according to the switching mode selected in step S30a. (¥ = u, v, w) is incremented. In step S56, it is determined whether or not two values of the counters Cu, Cv, and Cw are equal to or greater than a threshold value Cth. When a negative determination is made in step S56, in step S58, regarding the phase (leg) in which the switching state is switched by the switching mode selected in step S30a, the counter C ¥ is equal to or greater than the threshold Cth. It is determined whether or not the switching state of the phase is switched. If an affirmative determination is made in step S58, the process returns to step S30a in order to remove the switching mode studied here from the evaluation target by the evaluation function J. This process is for limiting the number of switching of the switching state to the threshold value Cth.

  On the other hand, if a negative determination is made in step S32, the counter C ¥ is initialized in step S60.

Note that when the processes of steps S58 and S60 are completed or when an affirmative determination is made in step S56, this series of processes is temporarily terminated.
<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, all of the switching modes 0 to 7 are temporarily set, and the evaluation function J is calculated for each switching mode. Then, when the voltage vector corresponding to the one having the maximum evaluation of the evaluation function J is an invalid voltage vector, any one of the voltage vectors V0 and V7 is set so as to equalize the period in which the voltage vectors V0 and V7 are adopted. Select whether to use.

  FIG. 17 shows details of the processing in step S24 according to the present embodiment. This process constitutes an invalid voltage vector period adjusting means. Note that, in FIG. 17, the same step numbers are assigned for convenience to those corresponding to the processing shown in FIG. 5.

  In the present embodiment, first, in step S31, a voltage vector corresponding to the switching mode that minimizes the evaluation function J is provisionally set as the next voltage vector V (n + 1). The invalid voltage vectors V0 and V7 are used to set the evaluation function J to the same value. However, in this process, if the evaluation function J of the invalid voltage vector is minimum, either one may be selected at random.

  If an affirmative determination is made in subsequent step S32, it is determined in step S64 whether or not the voltage vector V (n + 1) corresponding to the switching mode having the highest evaluation is the invalid voltage vectors V0 and V7. If it is an invalid voltage vector, it is determined in step S66 whether or not the value of the counter C0 that counts the number of times the voltage vector V0 is adopted is less than the threshold value Cth. If it is determined in step S66 that it is less than the threshold value Cth, in step S68, the voltage vector V (n + 1) corresponding to the next switching mode is set to the voltage vector V0, and the counter C0 is incremented.

  On the other hand, if a negative determination is made in step S66, it is determined in step S70 whether or not the value of the counter C7 that counts the number of times the voltage vector V7 is adopted is less than the threshold value Cth. If it is determined in step S70 that the threshold value is greater than or equal to the threshold Cth, counters C0 and C7 are initialized in step S72. On the other hand, when an affirmative determination is made in step S70 or when the process of step S72 is completed, in step S74, the voltage vector V (n + 1) corresponding to the next switching mode is set as the voltage vector V7 and the counter C7. Is incremented.

  On the other hand, if a negative determination is made in step S32, the counters C0 and C7 are initialized in step S76.

When a negative determination is made at step S64, or when the processes at steps S68, S74, and S76 are completed, this series of processes is temporarily terminated.
<Fifth Embodiment>
Hereinafter, the fifth embodiment will be described with reference to the drawings with a focus on differences from the fourth embodiment.

  In the present embodiment, the reactive voltage vector period adjusting unit is configured as a processing unit that is different from the fourth embodiment.

  FIG. 18 shows details of the processing in step S24 according to the present embodiment. This process constitutes an invalid voltage vector period adjusting means. Note that, in FIG. 18, the same step numbers are attached for convenience to those corresponding to the processing shown in FIG. 17.

  In this series of processes, when an affirmative determination is made in step S64, it is determined in step S80 whether or not the value of the counter C7 is greater than or equal to the value of the counter C0. If an affirmative determination is made in step S80, in step S82, the voltage vector V (n + 1) corresponding to the next switching mode is set to the voltage vector V0, and the counter C0 is incremented. On the other hand, when a negative determination is made in step S80, in step S84, the voltage vector V (n + 1) corresponding to the next switching mode is set as the voltage vector V7, and the counter C7 is incremented.

When the processes in steps S82 and S84 are completed, in steps S86, each of the counters C0 and C7 is multiplied by an attenuation coefficient K (0 <K <1). This is performed in place of the initialization processing of the counters C0 and C7, and is for avoiding the divergence of the values of the counters C0 and C7.
<Sixth Embodiment>
Hereinafter, the sixth embodiment will be described with reference to the drawings with a focus on differences from the fourth embodiment.

  In the present embodiment, the reactive voltage vector period adjusting unit is configured as a processing unit that is different from the fourth embodiment.

  FIG. 19 shows details of the processing in step S24 according to the present embodiment. This process constitutes an invalid voltage vector period adjusting means. Note that, in FIG. 19, the same step numbers are assigned for convenience to those corresponding to the processing shown in FIG.

  In this embodiment, when an affirmative determination is made in step S32, the maximum value ix of the currents iu, iv, iw of each phase is specified in step S88. In the subsequent step S90, it is determined whether or not the voltage vector V (n + 1) corresponding to the switching mode having the maximum evaluation is the invalid voltage vectors V0 and V7. If a positive determination is made in step S90, the process proceeds to step S92.

  In step S92, it is determined whether or not the counter Cxp that counts the energization period of the upper arm of the phase (x phase) that takes the maximum value ix is equal to or greater than the threshold value Cth. If it is determined that the threshold value is greater than or equal to the threshold Cth, in step S94, the voltage vector V (n + 1) corresponding to the next switching mode is set to the voltage vector V0, and the phase (x phase) below the maximum value ix. A counter Cxn that counts the energization period of the side arm is incremented. On the other hand, when a negative determination is made in step S92, in step S96, the voltage vector V (n + 1) corresponding to the next switching mode is set to the voltage vector V7, and the counter Cxp is incremented. The processes in steps S94 and S96 are performed by manipulating the period in which the reactive voltage vector V0 is employed and the period in which the reactive voltage vector V7 is employed, thereby energizing the upper arm in the phase with the maximum current (x phase). And the energization time of the lower arm are equalized. The energization time of the upper arm in the phase with the maximum current (x phase) is the energization time of either the switching element Sxp or the diode Dxp, and the lower arm in the phase with the maximum current (x phase). The energizing time is the energizing time of either the switching element Sxn or the diode Dxn.

  On the other hand, when a negative determination is made in step S90, if the next switching mode (voltage vector V (n + 1)) is to turn on the switching element Sxp, the counter Cxp is incremented, and the switching element Sxn is changed. If it is to be turned on, the counter Cxn is incremented.

  When the processes in steps S94, S96, and S98 are completed, it is determined in step S100 whether or not both of the counters C ¥ p and C ¥ n (¥ = u, v, w) are equal to or greater than a threshold value. If an affirmative determination is made in step S100 or a negative determination is made in step S32, the counters C ¥ p and C ¥ n are initialized in step S102.

When the process of step S102 is completed or when a negative determination is made in step S100, this series of processes is temporarily terminated.
<Seventh Embodiment>
Hereinafter, the seventh embodiment will be described with reference to the drawings with a focus on differences from the sixth embodiment.

  In the present embodiment, the reactive voltage vector period adjusting unit is configured as a processing unit that is different from that of the previous sixth embodiment.

  FIG. 20 shows details of the processing in step S24 according to the present embodiment. This process constitutes an invalid voltage vector period adjusting means. Note that, in FIG. 20, the same step numbers are assigned for convenience to those corresponding to the processing shown in FIG.

  In this embodiment, when an affirmative determination is made in step S90, it is determined in step S92a whether or not the value of the counter Cxp is greater than or equal to the value of the counter Cxn. This process is for determining which of the invalid voltage vectors V0 and V7 is to be selected. When an affirmative determination is made in step S92a, in step S94, the voltage vector V (n + 1) corresponding to the next switching mode is set to the invalid voltage vector V0, and the counter Cxn is incremented. On the other hand, when a negative determination is made in step S92a, in step S96, the voltage vector V (n + 1) corresponding to the next switching mode is set to the invalid voltage vector V7 and the counter Cxp is incremented.

When the processes in steps S94, S96, and S98 are completed, the counters Cxp and Cxn are multiplied by an attenuation coefficient K (0 <K <1) in step S104.
<Eighth Embodiment>
Hereinafter, the eighth embodiment will be described with reference to the drawings, centering on differences from the previous sixth embodiment.

  In the present embodiment, the reactive voltage vector period adjusting unit is configured as a processing unit that is different from that of the previous sixth embodiment.

  FIG. 21 shows details of the processing in step S24 according to the present embodiment. This process constitutes an invalid voltage vector period adjusting means. Note that, in FIG. 21, the same step numbers are assigned for convenience to those corresponding to the processing shown in FIG.

  In this embodiment, when an affirmative determination is made in step S32, it is determined in step S106 whether or not the voltage vector V (n + 1) with the highest evaluation of the evaluation function J is the invalid voltage vectors V0 and V7. When it is determined that the reactive voltage vectors are V0 and V7, in step S108, the maximum value of the temperature T ¥ p among the pair of the switching element S ¥ p of the upper arm and the diode D ¥ p connected in reverse parallel thereto. (Upper maximum temperature Tp) and the maximum value of the temperature T ¥ n (lower maximum temperature Tn) of the set of the switching element S ¥ n of the lower arm and the diode D ¥ n connected in reverse parallel thereto The higher one (maximum temperature Ty) is specified. This process is a process for specifying an arm corresponding to the one having the maximum integrated value of the calorific value among the set (distribution restricting element) of the switching element S ¥ # and the diode D ¥ #. Here, the temperature is a parameter having a correlation with the integrated value of the heat generation amount.

  In the subsequent step S110, it is determined whether or not the maximum temperature Ty is the upper maximum temperature Tp. If a negative determination is made, in step S112, the voltage vector V (n + 1) corresponding to the next switching mode is converted to the invalid voltage vector. If it is determined as V7 and an affirmative determination is made, the voltage vector V (n + 1) is set as the invalid voltage vector V0 in step S114. This process is a process of selecting a switching mode in which the current having the maximum calorific value is not energized. That is, for example, when a negative determination is made in step S110, the lower arm has the largest integrated value of the amount of heat generation, so by selecting the invalid voltage vector V7, the lower arm switching element S ¥ n And avoiding a situation of energizing the diode D ¥ n.

When a negative determination is made in steps S32 and S106 or when the processes in steps S112 and S114 are completed, the series of processes is temporarily ended.
<Ninth Embodiment>
Hereinafter, the ninth embodiment will be described with reference to the drawings with a focus on differences from the sixth embodiment.

  In the present embodiment, a prohibiting unit is configured to prohibit the adoption of a switching mode in which a combination of the switching element S ¥ # and the diode D ¥ # has the maximum integrated value of the calorific value.

  FIG. 22 shows details of the processing in step S16 according to the present embodiment. This process constitutes prohibition means. Note that, in FIG. 22, the same step numbers are attached for convenience to those corresponding to the processing shown in FIG. 5.

  In the present embodiment, when an affirmative determination is made in step S32, in step S116, the maximum value of the temperature T ¥ p of the pair of the switching element S ¥ p of the upper arm and the diode D ¥ p connected in reverse parallel thereto is determined. The higher one (maximum temperature Txy) of the maximum value of the temperature T ¥ n among the set of the switching element S ¥ n of the lower arm and the diode D ¥ n connected in reverse parallel thereto is specified. This process is a process for identifying the combination of the switching element S ¥ # and the diode D ¥ # that maximizes the integrated value of the heat generation amount. Here, the temperature is a parameter having a correlation with the integrated value of the heat generation amount.

In a succeeding step S118, it is determined whether or not the voltage vector V (n + 1) corresponding to the switching mode set in the step S30 does not energize the specified switching element Sxy and diode Dxy. If a negative determination is made in step S118, the temporary setting of the switching mode is prohibited, and the process returns to step S30. On the other hand, when an affirmative determination is made in step S118, this series of processes is temporarily terminated (based on the temporarily set switching mode, the process of the transition to step S18 in FIG. 4 is executed).
<Other embodiments>
Each of the above embodiments may be modified as follows.

About leg equalization means
In the second embodiment (FIG. 8), there may be a limit on the number of times that the switching modes corresponding to the same effective voltage vectors V1 to V6 are employed.

  The present invention is not limited to the one that is employed in a situation where the restriction that the number of legs that can be switched at a time is 1 or less is provided. For example, in the first embodiment, the number of switching legs in the switching state may be 2 or less.

  In the first embodiment, the number of switching of the switching state in each leg until the switching mode corresponding to the reactive voltage vector is selected again is “1”, but the present invention is not limited to this. For example, the specified number may be two or more. For example, each time a switching mode corresponding to the effective voltage vectors V1 to V6 is selected, the number of switching of the switching state is counted, and evaluation of the switching mode is performed to increase the number of switching although the number of switching is small. This can be done by designing the evaluation function J so as to be higher than the evaluation of the switching mode that increases the number of switching. Note that it is effective to set the number of switching to an odd number so that the reactive voltage vector V0 and the reactive voltage vector V7 are alternately adopted.

"Switch frequency equalization means"
In the third embodiment (FIG. 16), when the switching number of the switching state in the second leg reaches the threshold value Cth, even if the switching mode is selected under the condition for prohibiting switching of the switching state of the leg. Good. Such processing may be continued until the number of switching of the switching state in the last leg reaches the threshold value Cth.

  Moreover, you may set so that evaluation of the evaluation function J may become low, so that the difference between legs about the switching frequency of a switching state is large. This is, for example, the square of the difference in switching frequency between the U and V phases, the square of the difference in switching frequency between the V and W phases, and the switching frequency of the switching states between the W and U phases. This can be done by adding the sum of the difference and the square to the evaluation function J. Incidentally, the switching frequency here is calculated including switching of the switching state associated with what is temporarily set as the next switching mode (voltage vector V (n + 1)).

"Reactive voltage vector period adjustment means"
In the fourth embodiment (FIG. 17), the threshold values of the counter C0 and the counter C7 may be different from each other. Thereby, even if there is a difference in the heat generation amount between the switching element S ¥ # and the diode D ¥ #, the heat generation amount of the upper and lower arms can be made more uniform. That is, for example, when the U-phase actual current iu is maximum and is positive, the current continues to flow through the switching element Sup and the diode Dun at the time of locking. In the meantime, it is effective to make the thresholds different from each other in order to make the heat generation amounts of the switching element Sup and the diode Dun more uniform.

  For the same reason, the attenuation coefficient K in the fifth embodiment (FIG. 18) may be different between the counter C0 and the counter C7. Similarly, the threshold value Cth in the sixth embodiment (FIG. 19) may be different between the counter Cxp and the counter Cn. In the seventh embodiment (FIG. 20), the attenuation coefficient K may be different between the counter Cxp and the counter Cn.

  However, for the purpose of equalizing the energization period of the switching element S ¥ p and the diode D ¥ # of the upper arm in the phase where the current is maximum and the energization period of the switching element S ¥ n and the diode D ¥ n of the lower arm. The threshold values of the counter C0 and the counter C7 may be different from each other (the ratio between the adoption frequencies of the voltage vector V0 and the voltage vector V7 may be shifted from 1). This is because the proportion of the period in which the effective voltage vector is employed differs according to the modulation rate. That is, for example, as shown in FIG. 7A, when only the voltage vectors V0, V1, and V7 are used, the frequency of use of the voltage vectors V0 and V7 is made uniform so that the phase of the maximum current (U phase) can be obtained. Although the energization time of the upper and lower arms is equalized, the energization time deviates from a uniform one according to the proportion of the usage period of the voltage vector V1. In the example illustrated in FIG. 7A, the difference in energization time between the upper and lower arms is only 4%, but this difference is considered to increase when the modulation rate increases. For this reason, when the modulation rate increases as the required torque T * increases, the thresholds of the counters C0 and C7 may be different from each other. However, in this case, for example, when the electrical angle θ = −90 °, the voltage vector V1 is easily selected as the effective voltage vector. Therefore, it is desirable to increase the threshold value of the counter C0. On the other hand, when the electrical angle θ = 90 °, Since the voltage vector V4 is easily selected as the effective voltage vector, it is desirable to increase the threshold value of the counter C7.

  As described above, by variably setting the threshold values of the counters C0 and C7 according to the electrical angle θ and the modulation rate, it is possible to more uniformly control the energization time of the upper and lower arms of the phase where the current is maximum. However, instead of the modulation factor, the torque estimated from the required torque T * and the actual currents id and iq, the command current id * and iq *, the vector norm of the actual currents id and iq, and the like may be input. It is desirable that the threshold value is variably set according to the electrical angle θ according to the phase angle of the current vector.

"Acquisition means"
The acquisition means for acquiring information relating to the integrated value of the heat generation amount is not limited to acquiring the detected temperature T ¥ # for the switching element S ¥ # and the diode D ¥ #. For example, information on the amount of heat generated by switching the switching state once and the amount of heat generated per unit time due to conduction loss may be stored in advance, and a means for integrating the amount of generated heat each time may be provided.

“Prohibited measures”
In the ninth embodiment (FIG. 22), the integrated value (in this case, temperature) of the calorific value that prohibits energization is the highest temperature value itself of the set of the switching element S ¥ # and the diode D ¥ #. However, it is not limited to this. For example, energization may be prohibited when the temperature reaches a predetermined value. Further, for example, when the highest temperature reaches the specified temperature, the switching mode in which it is energized may be prohibited. Further, for example, when the reactive voltage vector period occupies a high ratio at the time of locking, when the reactive voltage vector is selected by the evaluation of the evaluation function J, the switching mode that is energized at the highest temperature is energized. The reactive voltage vector may be prohibited.

About prediction means
It is not limited to predicting only the control amount generated by the voltage vector V (n + 1) corresponding to the next switching mode. 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 id * (n + 2) and the difference between the predicted current iqe (n + 2) and the command current iq * (n + 2) The weighted average processing value with the absolute value may be used as a parameter for evaluating the degree of deviation between the predicted current and the command current. 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 switching mode of the inverter INV based on the command value and the predicted value is not limited to the current. For example, torque and flux linkage may be used, or only torque or flux linkage 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.

  The rotating machine is not limited to a surface magnet synchronous machine, and may be an arbitrary synchronous machine such as an embedded 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.

"Rotating machine drive area"
It is not restricted to what was shown in previous FIG. For example, the driving may be performed in a region below the rotational speed smaller than the rotational speed at which the torque becomes zero at the maximum modulation rate. Even in this case, if there is a rotational speed region where the maximum torque is constant, the proportion of the switching mode corresponding to the reactive voltage vector becomes large at the time of stop or in the extremely low speed rotational speed operation region. The effects equivalent to those of the above embodiments can be obtained. Note that this effect is from the rotational speed at which the torque that can be output begins to decrease (threshold speed ωth) to the rotational speed at which the torque becomes zero regardless of whether or not it is actually in the drive region under the condition that the maximum modulation rate is less than or equal to. This is particularly noticeable when the rotational speed region where the maximum torque is constant is wider than the rotational speed region.

  However, even if there is no region where the maximum torque is constant, for example, according to the first embodiment, the switching loss of a specific leg can be reduced by equalizing the switching frequency, or the upper arm It is possible to reduce the imbalance in energization time between the lower arm and the lower arm.

"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.

  The switching element constituting the DC / AC conversion circuit is not limited to the IGBT, and may be, for example, a MOS field effect transistor or the like.

  DESCRIPTION OF SYMBOLS 10 ... Motor generator (one Embodiment of a rotary machine), 20 ... Control apparatus, INV ... Inverter (One Embodiment of DC-AC conversion circuit).

Claims (4)

For a DC / AC converter circuit comprising a switching element for connecting a terminal of a rotating machine to each of a positive electrode and a negative electrode of a DC voltage source, and a rectifying means connected in reverse parallel to the switching element, the switching element of the DC / AC converter circuit In the control device for a rotating machine that controls the control amount having at least one of the current flowing through the rotating machine, the torque of the rotating machine, and the linkage flux of the rotating machine,
Predicting means for temporarily setting a switching mode indicating whether each of the switching elements is in an on state or in an off state, and predicting the control amount according to the temporarily set switching mode;
Determining means for determining a switching mode used for actual operation of the DC-AC converter circuit based on a prediction result by the prediction means;
Operating means for operating the switching element to be in the switching mode determined by the determining means,
The determination unit increases the evaluation of the switching mode in which the difference between the control amount predicted by the prediction unit and the command value is small, and determines the switching mode with the high evaluation as the switching mode used for the actual operation. Is,
The determining unit is configured to reduce a difference between the respective calorific values of the switching element and a flow regulating element including a rectifying unit connected in reverse parallel to the switching element when determining a switching mode used for the actual operation. With priority means to prioritize modes ,
The priority means is connected to the flow regulating element connected to the positive electrode of the DC voltage source and the negative electrode of the DC voltage source for the maximum current flowing among the legs constituting the DC / AC conversion circuit. Intra-leg equalization means for operating the switching mode to reduce and control the difference in calorific value with the flow regulating element,
The intra-leg equalization means includes a switching mode in which all of the switching elements of the lower arm are turned on when the evaluation of the switching mode corresponding to the reactive voltage vector is higher than the evaluation of the switching mode corresponding to the effective voltage vector. depending all the switching elements of the upper arm is determined in any of a switching mode which is turned on, the control device of the rotary machine, wherein Rukoto includes a reactive voltage vector period adjustment means for the reduction control. The reactive voltage vector period adjusting means controls a ratio of a period in which all of the switching elements of the lower arm are turned on to a period in which all of the switching elements of the upper arm are turned on to a target value. so, all the switching elements of the lower arm is turned on to become a switching mode and all the switching elements of the upper arm is turned on and becomes a switching mode of claim 1, wherein the performing of the decision and any Control device for rotating machine. The reactive voltage vector period adjusting means is configured such that, for the leg having the maximum flowing current, an energization period of the flow restriction element connected to the positive electrode of the DC voltage source and the flow restriction element connected to the negative electrode of the DC voltage source. In order to control the ratio to the energization period of the current to a target value, it is determined whether the switching mode in which all of the switching elements of the lower arm are turned on or the switching mode in which all of the switching elements of the upper arm are turned on The control device for a rotating machine according to claim 1, wherein: The reactive voltage vector period adjusting means includes acquisition means for acquiring information related to the integrated value of the calorific value relating to each of the flow regulation elements, and a switching mode in which all of the switching elements of the lower arm are turned on and switching of the upper arm The use of the switching mode for energizing the acquired integrated value of the calorific value among the pair of switching modes with the switching mode in which all of the elements are turned on reaches a predetermined value is prohibited. Item 2. A rotating machine control device according to Item 1 .