JP4396762B2 - Control device for multi-phase rotating machine - Google Patents

Description

  The present invention relates to a control device for a multiphase rotating machine that controls the rotation of the multiphase rotating machine by operating a switching element of a power conversion circuit connected to the multiphase rotating machine.

  As this type of control device, for example, as seen in Patent Document 1 below, when all phases of a three-phase motor are short-circuited, the current (phase current) flowing through each phase becomes zero, and the phase current It has also been proposed to perform control to match the timing at which the change in the value becomes zero. Here, attention is focused on the fact that when all phases are short-circuited, the induced voltage at the timing when the phase current becomes zero is determined by the amount of change in the phase current. For this reason, according to the above control, the zero-cross timing of the induced voltage of each phase can be matched with the zero-cross timing of the current. Therefore, the three-phase motor can be appropriately controlled without providing a dedicated sensor for detecting the rotation angle of the three-phase motor.

In addition, as another control apparatus for a multiphase rotating machine, for example, there is one which can be found in Patent Document 2 below.
JP 2005-102350 A Japanese Patent No. 3598909

  By the way, in the said control apparatus, since the electric current is detected in the voltage vector V0 period when all the switching elements of the lower arm of the inverter connected to the three-phase motor are in the ON state, the phase current is increased as the modulation rate is increased. The change detection period is shortened. For this reason, there is a possibility that the detection accuracy of the change of the phase current is lowered as the modulation rate becomes higher.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to control rotation of the multiphase rotating machine by operating a switching element of a power conversion circuit connected to the multiphase rotating machine. It is an object of the present invention to provide a control device for a multiphase rotating machine that can maintain high controllability regardless of the modulation rate.

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

  The invention according to claim 1 is a current zero-cross detection means for detecting a zero-cross timing of a line current that is a current difference between any two short-circuited when at least two phases of the multi-phase rotating machine are short-circuited; A change zero cross detection means for detecting a zero cross timing of a change amount of the line current between any two phases when the at least two phases are short-circuited, and a detection value of the current zero cross detection means and the change zero cross detection means A command voltage setting means for setting a command value of a voltage to be applied to the multiphase rotating machine, and an operating means for operating a switching element of a power conversion circuit connected to the multiphase rotating machine based on the command value. It is characterized by providing.

  At the zero cross timing when the line current becomes zero, the induced voltage between the lines can be expressed by the amount of change in the line current. For this reason, the zero cross timing of the line current and the zero cross timing of the change of the line current at the zero cross timing at which the line current becomes zero include information on the relationship between the line current and the induced voltage between the lines. Become. In the above invention, paying attention to this point, the rotation of the multiphase rotating machine can be controlled by setting the voltage command value using the relation information. In particular, since a phase difference occurs between the line current and the current of each phase, the period that can be detected by the current zero-cross detection means and the change zero-cross detection means even at high modulation rates by using the line current It becomes easy to secure. For this reason, according to the said invention, the controllability can be maintained highly irrespective of a modulation rate.

  According to a second aspect of the present invention, in the first aspect of the invention, the command voltage setting means controls the difference between the zero-cross timing of the line current and the zero-cross timing of the change amount of the line current to a target value. Therefore, the command value is set accordingly.

  According to the above invention, by determining the target value for the difference between the zero cross timings, it is possible to perform appropriate control according to the request. For example, in an embedded magnet synchronous motor, if the target value is set to “0”, the torque maximization control for generating the maximum torque with the minimum current can be performed, and the efficiency can be improved by setting the value to a predetermined value other than zero. Maximum control is possible.

According to a third aspect of the present invention, in the second aspect of the present invention, the difference between the two zero cross timings is the zero cross timing when the polarity of the amount of change in the line current changes from one of positive and negative to the other. polarity of the line-to-line current, characterized by comprising defined as the difference between the zero-cross timing when changed to the one from the other and.

  When the induced voltage between the lines is greater than zero, the amount of change in current is negative, and when the induced voltage between the lines is less than zero, the amount of change in current is positive. For this reason, the induced voltage between the lines can be expressed by reversing the change polarity of the current between the lines. In the above invention, paying attention to this point, the difference between the two zero cross timings can be appropriately defined.

  According to a fourth aspect of the present invention, in the invention of the second or third aspect, the rotational speed of the multiphase rotating machine is determined based on a time interval between zero cross timings of changes in line current detected by the change zero cross detection means. A speed calculating means for calculating, and a means for setting the target value of the difference between the zero cross timings based on the calculated rotation speed are further provided.

  The time difference corresponding to the phase difference between the same zero cross timings varies depending on the rotation speed. In this regard, in the above invention, the phase difference can be appropriately defined as the time interval by setting the target value of the difference between the zero cross timings based on the rotation speed.

  According to a fifth aspect of the present invention, in the invention according to any one of the second to fourth aspects, the command voltage setting means determines the amplitude, phase difference, and electrical angular velocity of the command value based on a difference between the zero cross timings. At least one of the above is variably set.

  The zero cross timing can be advanced as the amplitude is increased. The zero cross timing can also be advanced by advancing the phase. Further, the zero cross timing can be advanced by increasing the electrical angular velocity. In the above invention, paying attention to these points, the difference between the zero cross timings can be controlled to the target value.

  According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, the multi-phase rotating machine is based on a time interval between zero-cross timings of changes in line current detected by the change zero-cross detection means. And a feedback control means for feedback-controlling the calculated rotational speed to a rotational speed command value for the multiphase rotating machine.

  When the rotational speed is controlled to the command value, the actual rotational speed may not necessarily be controlled to the command value, for example, by feedback control of the difference between the zero cross timings to the target value. In this regard, in the above invention, the rotational speed can be appropriately controlled to the command value by feedback control of the rotational speed to the command value.

  According to a sixth aspect of the invention, as in the seventh aspect of the invention, the command voltage setting means includes the feedback control means, whereby the calculated rotation speed and the rotation with respect to the multiphase rotating machine are The voltage command value may be set based on a difference from the speed command value.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the multi-phase rotating machine is a three-phase rotating machine, and the current zero cross detecting means and the change zero cross detecting means are the power The detection value of either the high potential side detection means for detecting the current flowing in each phase of the upper arm of the conversion circuit or the low potential side detection means for detecting the current flowing in each phase of the lower arm of the power conversion circuit is used. The detection is performed, and the timing for performing the detection is determined according to the amplitude of the command value of the voltage, when the three phases are short-circuited or when the two phases are short-circuited. And switching.

  When the zero cross timing is detected when the three phases are short-circuited, the detectable zero cross timing occurs six times within one rotation period of the electrical angle. On the other hand, when the two phases are short-circuited, the zero cross timing that can be detected by detecting the current of the two phases occurs three times in one rotation period. Thus, it is easier to maintain a high detection frequency of the zero cross timing when the three phases are short-circuited. However, when the three phases are short-circuited, the detectable period becomes shorter as the amplitude of the voltage command value increases. For this reason, the change in the line current within the detectable period is reduced, and the detection accuracy is lowered. On the other hand, since the two-phase short-circuit period occurs on both sides of the three-phase short-circuit period, these two two-phase short-circuit periods have some degree even if the amplitude of the command value increases. Can be maintained. In the above invention, paying attention to this point, switching according to the amplitude of the command value makes it possible to maintain high detection accuracy of the zero cross timing of the amount of change in the line current regardless of the amplitude.

  The invention according to claim 9 is the invention according to any one of claims 1 to 7, wherein the current zero-cross detection means and the change zero-cross detection means detect a current flowing in each phase of the upper arm of the power conversion circuit. The detection is performed using the detection values of both the high potential side detection means and the low potential side detection means for detecting the current flowing in each phase of the lower arm of the power conversion circuit, and the high potential Which one of the side detection means and the low potential side detection means is used is switched according to a change in the electrical angle of the multiphase rotating machine.

  The longer of the period during which the line current can be detected using the high potential side detection means and the period during which the line current can be detected using the low potential side detection means, It depends on the corner. In this regard, in the above-described invention, it is possible to ensure an appropriate period as a detectable period by switching which one of the high potential side detection unit and the low potential side detection unit is used in accordance with the change in the electrical angle.

  Note that switching between the high potential side detection unit and the low potential side detection unit is not necessarily performed based on the detection value of the electrical angle. In short, the above-described switching may be performed based on a parameter that can be determined as to which of the two changes as the electrical angle changes.

  According to a tenth aspect of the present invention, in the ninth aspect of the invention, the power conversion of the command value of the voltage is maintained while maintaining a difference in value between the two phases of the command value of the voltage set by the command voltage setting means. Two-phase modulation means for matching the voltage difference between any one of the pair of input terminals of the circuit and the voltage of any one of the input terminals is further provided, and the operation means is modulated by the two-phase modulation means. The switching element is operated so that the command value is set, and the two-phase modulation means is any of the above when the current zero cross detection means and the change zero cross detection means use the high potential side detection means. The voltage at the input terminal on the high potential side is used as the voltage at the input terminal, and the current zero cross detection means and the change zero cross detection means use the low potential side detection means. Sometimes characterized by using the voltage of the input terminal of the low-potential side as a voltage of the one input terminal.

  When the two-phase modulation process is performed, a period during which the switching element connected to either side of the pair of input terminals is turned on becomes longer. In this regard, in the above invention, when the current zero cross detection means and the change zero cross detection means use the high potential side detection means, the command value is corrected to the voltage side of the input terminal on the high potential side so that the input on the high potential side can be corrected. The time during which the switching element connected to the terminal is turned on can be extended. For this reason, it is possible to extend the period during which the line-to-line current and the like can be detected using the high potential side detection means. On the other hand, when the current zero cross detection means and the change zero cross detection means use the low potential side detection means, the command value is corrected to the voltage side of the low potential side input terminal, thereby being connected to the low potential side input terminal. The time during which the switching element is turned on can be extended. For this reason, it is possible to extend the period during which the line-to-line current and the like can be detected using the low potential side detection means.

  The invention according to an eleventh aspect is the invention according to any one of the first to ninth aspects, wherein the command value of the voltage set by the command voltage setting means extends a period during which the at least two phases are short-circuited. The apparatus further comprises means for changing a command value of the voltage, and the operation means operates the switching element so as to be the changed command value.

  In the above invention, since the voltage command value is changed so as to extend the period during which the at least two phases are short-circuited, there is a concern that the detection accuracy of the zero cross timing of the amount of change in the line current may be lowered. This situation can be avoided under certain circumstances.

  The invention according to claim 12 is the invention according to any one of claims 1 to 11, wherein the command value of the voltage is maintained while maintaining a difference between the two phases of the command value of the voltage set by the command voltage setting means. Among them, the power conversion circuit further includes two-phase modulation means for matching a voltage having the smallest difference from any one of the pair of input terminals with any one of the voltages, and the operation means includes the two-phase modulation means. The switching element is operated so as to obtain a modulated command value.

  When the two-phase modulation process is performed, a period during which the switching element connected to either side of the pair of input terminals is turned on becomes longer. In the above invention, paying attention to this point, by performing the two-phase modulation processing, the period during which the switching element connected to either side of the pair of input terminals is turned on is extended. As a result, the period during which two or more phases are short-circuited can be extended, and as a result, the detectable period by the current zero-cross detection means and the change zero-cross detection means can be extended.

  A thirteenth aspect of the present invention is the correction means according to any one of the first to twelfth aspects, wherein the command voltage is corrected based on a change in amplitude of a current having a frequency higher than the electrical angular velocity of the multiphase rotating machine. Is further provided.

  The frequency of occurrence of the zero cross timing of the line current and the zero cross timing of the amount of change in the line current is limited. For this reason, rotation control based on the zero cross timing cannot be performed in the period between these zero cross timings. Here, there is a correlation between the phase of the current flowing through the rotating machine and its amplitude. That is, when the current phase changes, the amplitude also changes. In the above invention, paying attention to this point, the phase of the rotating machine can be controlled even during the period between the zero cross timings by grasping the change in the phase according to the change in the amplitude of the current.

According to a fourteenth aspect of the present invention, in the invention according to any one of the first to thirteenth aspects, the change zero-cross detection unit is configured to detect the line current between the two phases when the arbitrary two phases are short-circuited. difference between the values at two different sampling timings, and the differential value of the line currents of the two phases when the arbitrary two phases are short-circuited, and the two phases when the arbitrary two phases are short-circuited be carried out starting point and the difference between the line current and the product of the time interval in any of the end points, the detected based on any one of said time interval and the integral value in a predetermined time interval of the line current It is characterized by.

  According to the above invention, the zero cross timing can be appropriately detected based on the detection of the change amount of the line current. In particular, in the case of the method based on the integral value at the predetermined time interval, the influence of noise mixed in the line current can be suitably suppressed.

  In the invention according to any one of claims 1 to 14, according to the invention according to claim 15, the current zero-cross detection means and the change zero-cross detection means include each phase of the upper arm of the power conversion circuit and According to at least one of a shunt resistor connected between the positive input terminals of the power conversion circuit and each phase of the lower arm of the power conversion circuit and a negative input terminal of the power conversion circuit The detection may be performed based on a voltage drop.

  In the invention according to any one of claims 1 to 14, according to the invention according to claim 16, the current zero-cross detection means and the change zero-cross detection means are the switching elements of the upper arm of the power conversion circuit. The detection may be performed based on a voltage drop caused by at least one of a voltage drop amount between the input / output terminals and a voltage drop amount between the input / output terminals of the switching element of the lower arm of the power conversion circuit.

  Further, in the invention according to any one of claims 1 to 16, the multi-phase rotating machine is a three-phase rotating machine as in the invention according to claim 17, and the current zero-cross detecting means and the change zero-cross detecting means are The detection may be performed when all phases of the multiphase rotating machine are short-circuited.

  According to the above invention, for example, even when only means for detecting the current flowing in each phase of either the upper arm or the lower arm is provided, the zero cross timing is detected six times within one rotation period of the electrical angle. can do.

Further, in the invention according to any one of claims 1 to 16, according to the invention according to claim 18, the multi-phase rotating machine is a three-phase rotating machine, and the change zero cross detecting means is the multi-phase rotating machine. Performing the detection based on the amount of change between the line currents in each of the periods in which any two phases, which are a pair of periods adjacent in time series in a period in which all phases of the machine are short-circuited, are short-circuited It is characterized by.

  According to the said invention, compared with the case where the variation | change_quantity of a line current is detected in the short circuit period of all phases, the period which can be detected can be lengthened.

  A nineteenth aspect of the present invention is the invention according to any one of the first to eighteenth aspects, further comprising a determination unit that determines whether the multiphase rotating machine is in powering control or regenerative control. The command voltage setting means takes into account the determination result of the determination means when setting the command value.

  Appropriate voltages for adjusting the phase of the current differ from each other due to the fact that the polarity of the current is reversed between the power running control and the regenerative control. In the above invention, in view of this point, the command voltage is appropriately set in both the power running control and the regenerative control by taking into account the determination result of the power running control or the regenerative control when setting the command voltage. Can be set.

  According to a twentieth aspect of the invention, in the invention of the nineteenth aspect, the command voltage setting means is configured to control at least an amplitude, a phase difference, and an electrical angular velocity of the command value so as to control a difference between the zero cross timings to a target value. The at least one operation direction when the difference between the difference and the target value is the same during power running control and regenerative control of the multiphase rotating machine. It is characterized by being opposite to each other.

  During power running control and regenerative control, the phase relationship between the induced voltage and the line current is opposite to each other. Therefore, the amplitude and phase difference of the command voltage and the electrical angular velocity are controlled to control the above difference to the target value. The directions are opposite to each other. In the above invention, by paying attention to this point, the command voltage can be set appropriately.

  According to a twenty-first aspect of the present invention, in the twentieth aspect, the command voltage setting means is configured to control the difference between the zero cross timing of the amount of change and the zero cross timing of the line current to the target value. And the phase is set so that the phase is advanced so that the difference is shifted to the delay side with respect to the target value, and the difference is The phase is set so as to be delayed as the target value is shifted toward the delay side.

  In the above invention, the command voltage can be manipulated so that the difference in the zero cross timing of the line current with respect to the zero cross timing of the change amount appropriately follows the target value.

  According to a twenty-second aspect of the present invention, in the invention according to the twentieth or twenty-first aspect, the command voltage setting means controls the difference in the zero cross timing of the line current with respect to the zero cross timing of the change amount to the target value. An amplitude of a command value is variably set, and during the power running control, the amplitude is increased so that the difference is shifted to the delay side with respect to the target value, and during the regenerative control, the difference is the target value. The amplitude is reduced as the position shifts to the delay side.

  In the above invention, the command voltage can be manipulated so that the difference in the zero cross timing of the line current with respect to the zero cross timing of the change amount appropriately follows the target value.

  According to a twenty-third aspect of the present invention, in the invention according to any one of the twenty-second to twenty-second aspects, the command voltage setting means determines a difference of a zero-cross timing of the line current with respect to a zero-cross timing of the change amount as the target. The electrical angular velocity of the command value is variably set to control to a value, and at the time of the power running control, the electrical angular velocity is increased so that the difference is shifted to the delay side with respect to the target value, and the regenerative control is performed. In some cases, the electrical angular velocity is reduced as the difference deviates from the target value.

  In the above invention, the command voltage can be manipulated so that the difference in the zero cross timing of the line current with respect to the zero cross timing of the change amount appropriately follows the target value.

  The invention according to claim 24 is the invention according to any one of claims 19 to 23, wherein the multi-phase rotating machine is a three-phase rotating machine, and the judging means The determination is performed based on the phase current polarity of a phase other than the arbitrary two phases.

  The relationship between any two-phase line current of the three-phase rotating machine and the remaining one-phase current does not change between power running control and regenerative control. However, the relationship between the change polarity of the change amount and the polarity of the phase current is opposite between the power running control and the regenerative control. For this reason, this relationship can be utilized in order to distinguish power running control from regeneration control. In the above invention, in view of this point, power running control and regenerative control can be accurately distinguished.

  A twenty-fifth aspect of the invention is characterized in that, in the twenty-fourth aspect of the invention, the determination means makes the determination based on the change polarity and the polarity of the phase current at the zero cross timing of the change amount.

  In the above invention, the power running control and the regenerative control can be accurately distinguished in view of the fact that the relationship between the change polarity of the change amount and the polarity of the phase current is opposite between the power running control and the regenerative control. .

(First embodiment)
Hereinafter, a first embodiment in which a control device for a multiphase rotating machine according to the present invention is applied to a control device for a three-phase motor provided in an in-vehicle air conditioner will be described with reference to the drawings.

  FIG. 1 shows the overall configuration of the electric motor and its control system.

  The illustrated electric motor 10 is an embedded magnet type synchronous motor, and is a blower motor of an in-vehicle air conditioner. An inverter 12 is connected to the three phases (U phase, V phase, and W phase) of the electric motor 10. This inverter 12 is a three-phase inverter, and includes switching elements SW1 and SW2, switching elements SW3 and SW4, and switching elements SW5 and SW6 so that each of the three phases and the positive electrode side or the negative electrode side of the battery 14 are electrically connected. It has a parallel connection. Furthermore, the inverter 12 includes flywheel diodes D1 to D6 connected in parallel to the switching elements SW1 to SW6. And the connection point which connects switching element SW1 and switching element SW2 in series is connected with the U phase of the electric motor 10. FIG. Further, a connection point connecting the switching element SW3 and the switching element SW4 in series is connected to the V phase of the electric motor 10. Further, a connection point connecting the switching element SW5 and the switching element SW6 in series is connected to the W phase of the electric motor 10. Incidentally, these switching elements SW1 to SW6 are constituted by MOS transistors in this embodiment.

  A smoothing capacitor 16 and a voltmeter 18 are connected to both ends of each set of switching elements SW1 and SW2, switching elements SW3 and SW4, and switching elements SW5 and SW6 of the inverter 12.

  A shunt resistor Ru that senses current flowing through the switching element SW2 and the diode D2 is connected in series with the switching element SW2 between the negative terminal side of the battery 14 and the switching element SW2 in the inverter 12. In addition, a shunt resistor Rv that senses current flowing through the switching element SW4 and the diode D4 is connected in series with the switching element SW4 between the negative electrode terminal side of the battery 14 and the switching element SW4. Further, a shunt resistor Rw that senses current flowing through the switching element SW6 and the diode D6 is connected in series with the switching element SW6 between the negative electrode terminal side of the battery 14 and the switching element SW6.

  On the other hand, the control device 20 takes in the outputs of the shunt resistors Ru, Rv, Rw (voltage drop amounts due to the shunt resistors Ru, Rv, Rw). And the control apparatus 20 operates switching element SW1-SW6 via the gate drive circuit 22 based on each electric current etc. which flow through the three phases of the said electric motor 10. FIG.

  FIG. 2 shows, among the processes performed by the control device 20, a process related to generation of operation signals for the switching elements SW <b> 1 to SW <b> 6 in particular.

  The amplitude setting unit 30 sets the amplitude Vm of the command voltages Vuc1, Vvc1, and Vwc1 of each phase based on the speed command value (speed command value ωd) for the electric motor 10. Here, the amplitude Vm may be set by multiplying the speed command value ωd by the gain Kω.

  The command voltage setting unit 32 sets the command voltages Vuc1, Vvc1, and Vwc1 based on the amplitude Vm determined by the amplitude setting unit 30, the speed command value ωd, and the phase φ set by the phase setting unit 34 described in detail later. To do.

  The duty signal generator 36 divides the command voltages Vuc 1, Vvc 1, and Vwc 1 by “½” of the voltage VB of the battery 14, thereby normalizing the duty signal by “½” of the voltage VB of the battery 14. Du1, Dv1, and Dw1 are generated.

  The two-phase modulation unit 38 performs two-phase modulation in which the smallest one of the duty signals Du 1, Dv 1, Dw 1 is kept in agreement with the negative potential of the battery 14 while maintaining the difference between the phases. FIG. 3 shows a procedure of processing performed by the two-phase modulation unit 38. In this series of processing, in step S10, the offset correction amount Δ of the duty signals Du1, Dv1, Dw1 is calculated. The offset correction amount Δ is a difference in potential at the negative terminal of the battery 14 with respect to the minimum value of the duty signals Du1, Dv1, Dw1. In other words, the difference is “−1” with respect to the duty signals Du1, Dv1, and Dw1. In step S12, duty signals Du, Dv, and Dw are calculated by adding an offset amount Δ to the duty signals Du1, Dv1, and Dw1.

  In the subsequent step S14, it is determined whether or not there is a duty signal Du, Dv, Dw whose absolute value is greater than one. This process determines whether or not guard processing is necessary for the duty signals Du, Dv, and Dw. When an affirmative determination is made in step S14, a guard process is performed in step S16 to limit the absolute value to “1” for those whose absolute value exceeds “1”. When the process of step S16 is completed or when a negative determination is made in step S14, this series of processes is temporarily terminated. The duty signals Du, Dv, and Dw calculated in this way are signals obtained by standardizing the final command voltages Vuc, Vvc, and Vwc with “½” of the voltage VB of the battery 14.

  In the PWM signal generator 40 shown in FIG. 2, the operation signals gup, gun, gvp, gvn, gwp, gwn of the switching elements SW1 to SW6 are obtained based on the magnitude relationship between the duty signals Du, Dv, Dw and the carrier signal. Generate. In particular, in the present embodiment, as shown in FIG. 4, the command voltages Vuc1, Vvc1, Vwc1 and duty signals Du, Dv, Dw are calculated in synchronization with the carrier cycle. FIG. 4A shows the carrier according to this embodiment, and FIG. 4B shows the calculation timing of the duty signals Du, Dv, Dw. As shown in the drawing, the carrier according to the present embodiment is an isosceles triangular signal having the same ascending speed and descending speed. The duty signals Du, Dv, Dw are calculated every time the carrier becomes the lower limit value.

  FIG. 5 shows how the operation signals gun, gvn, and gwn are generated by the PWM signal generator 40. Specifically, FIG. 5 (a) shows an enlarged carrier, FIG. 5 (b) shows the transition of the U-phase operation signal gun, and FIG. 5 (c) shows the V-phase operation signal gvn. FIG. 5D shows the transition of the W-phase operation signal gwn. As shown in the figure, the duty signals Du, Dv, and Dw do not change over one period until the carrier reaches the next lower limit value. For this reason, the magnitude relationship between the duty signals Du, Dv, and Dw and the carrier is axisymmetric with respect to the timing at which the carrier becomes the upper limit value. Therefore, the operation signals gun, gvn, and gwn are also symmetrical with respect to the timing at which the carrier reaches the upper limit value.

  The operation mode of the switching elements SW1 to SW6 is represented by eight voltage vectors shown in FIG. Here, the voltage vector V0 expresses that all the switching elements SW2, SW4, SW6 of the lower arm are in the ON state. The odd voltage vectors V1, V3, and V5 represent that the upper switching element of only one phase is on. Further, the even voltage vectors V2, V4, and V6 represent that the switching elements in the lower stage of only one phase are in the on state. Voltage vector V7 expresses a state in which all of switching elements SW1, SW3, and SW5 of the upper arm are on.

  The phase setting unit 34 shown in FIG. 2 operates the phase φ so as to perform maximum torque control that maximizes the torque generated while minimizing the current flowing through the motor 10. As shown in FIG. 7, this can be realized by causing a current to flow in a phase advanced by 90 degrees with respect to the magnet of the electric motor 10. In this case, as shown in FIG. 7A and FIG. 7B, the phase of the induced voltage of each phase and the phase of the phase current coincide. Moreover, as shown in FIG.7 (c) and FIG.7 (d), the phase of the induced voltage between lines (between UV phase, between VW phases, and between WU phases) and the phase of a line current are also in agreement.

  Therefore, in order to perform maximum torque control, as shown in FIG. 8, when the phase of the line current is delayed with respect to the phase of the line induced voltage, the phase of the line current is advanced and the line induced voltage is increased. When the phase of the line current advances with respect to the phase, the phase of the line current may be delayed.

  In the present embodiment, in order to perform the above control, in the voltage vector V0, the zero cross timing at which the line current becomes zero coincides with the zero cross timing at which the change amount of the line current becomes zero. This will be described below.

  In the period of the voltage vector V0, each one-phase equivalent circuit is a series circuit of the resistance component R, the inductance component L, and the induced voltage eU generation source of the electric motor 10, as illustrated for the U phase in FIG. For this reason, it is defined by the following formula (c1).

R × Iu + L (dIu / dt) + eU = 0 (c1)
Similarly, the following formula (c2) is established for the V phase.

R × Iv + L (dIv / dt) + eV = 0 (c2)
When (c2) is subtracted from the above (c1),
R × (Iu−Iv) + L (dIu / dt−dIv / dt) + (eU−eV) = 0
That is, R × Iuv + L × (dIuv / dt) + eUV = 0 (c3)
In the above formula (c3), when the line current Iuv becomes zero, the following formula is established.

eUV = −L × (dIuv / dt) (c4)
According to the above equation (c4), the line induced voltage eUV when the line current becomes zero can be expressed by the amount of change in the line current. In particular, in order to make the line induced voltage eUV when the line current becomes zero, the amount of change in the line current should be zero when the line current becomes zero.

  Therefore, in the present embodiment, as shown in FIG. 2, the polarity detection unit 42 that detects the polarity of the line-to-line current based on the voltage drop amounts ru, rv, and rw due to the shunt resistors Ru, Rv, and Rw, And a change polarity detector 44 for detecting the polarity of the change amount of the current. Then, the zero cross timing of the line current as the polarity inversion timing detected by the polarity detector 42 and the zero cross timing of the amount of change in the line current as the polarity inversion timing detected by the change polarity detector 44. Based on this, the phase setting unit 34 sets the phases of the command voltages Vuc1, Vvc1, and Vwc1. FIG. 10 shows a processing procedure performed by the polarity detection unit 42 and the change polarity detection unit 44. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processing, first, in step S20, the end timing Tf of the voltage vector V0 is calculated based on the maximum values of the duty signals Du, Dv, Dw. That is, the period of the voltage vector V0 is a period in which the maximum values of the duty signals Du, Dv, Dw are smaller than the carrier, so that the period of the voltage vector V0 is known based on the maximum values of the duty signals Du, Dv, Dw. be able to. Therefore, the end timing Tf of the voltage vector V0 is calculated based on the maximum values of the duty signals Du, Dv, Dw.

  In a succeeding step S22, it is determined whether or not the voltage vector V0 period has started. This process can be performed based on the logical values of the operation signals gun, gvn, and gwn. When it is determined that it is the start time of the voltage vector V0 period, the corresponding two-phase line currents Iuv, Ivw, Iwu (line current I (n-1)) are calculated in step S24. Here, the “corresponding two phases” are switched in electrical angles every “60 °”, and each “60 °” region includes one zero-cross timing. For this reason, the corresponding two phases are assumed to be two phases that are assumed to include the zero cross timing in the region.

  When the detection of the line current I (n−1) is completed, the process waits until a specified time shorter than the end timing Tf by a predetermined time α (step S26: NO). When the prescribed time is reached, the same two-phase line current I (n) as in step S24 is detected. In the subsequent step S30, the polarity of the line current is calculated. Here, the sign (polarity) of the sum of the line current I (n−1) detected in step S24 and the line current I (n) detected in step S28 is the polarity of the line current. Further, in step S32, the polarity of the change amount of the line current is calculated. Here, the polarity of the change in the line current is calculated based on the sign (polarity) of the difference between the line current I (n) detected in step S30 with respect to the line current I (n-1) detected in step S24. To do.

  In addition, when the process of step S32 is completed, this series of processes is once complete | finished.

  FIG. 11 shows a procedure of processing performed by the phase setting unit 34. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processes, first, in step S40, the inversion timing of the polarity of the line current is calculated. This process calculates the zero cross timing Φ (I = 0) of the line current. In subsequent step S42, the inversion timing of the change polarity of the line current is calculated. In this process, the zero cross timing Φ (dI / dt = 0) of the change amount of the line current is calculated. In step S44, based on the time difference ΔΦ of the zero cross timing Φ (I-0) calculated in step S40 with respect to the zero cross timing Φ (dI / dt = 0) calculated in step S42, the command voltages Vuc1, Vvc1, The phase φ of Vwc1 is calculated. The time difference ΔΦ is the time difference between the zero-cross timings of the same phase between the phase of the line current and the polarity of the change amount of the line current inverted. This is due to the reason shown in FIG.

  12A shows the transition of the induced voltage between the lines, FIG. 12B shows the transition of the line current, and FIG. 12C shows the change amount of the line current in the voltage vector V0 period. Shows the transition. As shown in the figure, the amount of change in the line-to-line current in the voltage vector V0 period is reversed in phase with the induced voltage between the lines. This is the result of the above equation (c4). For this reason, in order to make the phases of the induced voltage and the line current match, it is necessary to match the phase of the line current and the phase obtained by inverting the polarity of the change amount of the line current. In FIG. 12B, the behavior of the line current during the voltage vector V0 period is schematically represented by a thick line.

  In step S44 of FIG. 11, the phase φ is calculated based on the proportional integration calculation of the time difference ΔΦ. Here, when the zero cross timing Φ (I = 0) of the line current is delayed from the zero cross timing Φ (dI / dt = 0) of the change amount of the line current, the phase φ is advanced. On the other hand, when the zero-cross timing Φ (I = 0) of the line current is advanced with respect to the zero-cross timing Φ (dI / dt = 0) of the change amount of the line current, the phase φ is retarded.

  In addition, when the process of step S44 is completed, this series of processes is once complete | finished.

  With the above processing, maximum torque control can be performed. In particular, in the present embodiment, the period of the voltage vector V0 in the vicinity of the zero cross timing can be extended by performing the two-phase modulation process and using the zero cross timing of the line current. For this reason, it is possible to calculate the change of the line current with high accuracy. That is, by performing two-phase modulation as shown in FIG. 13 (a1) and converting the voltage actually applied to the motor 10 to the command voltages Vuc, Vvc, Vwc, the voltage as shown in FIG. 13 (b1) is obtained. The period of the vector V0 is expanded as compared with the case shown in FIGS. 13 (a2) and 13 (b2). As a result, as shown in FIG. 14, the zero cross timing can be detected six times within one rotation period of the electrical angle while ensuring the length of the voltage vector V0. Here, FIG. 14 (a1) shows a transition example of the voltage vector, FIG. 14 (b1) shows the transition of the line current, FIG. 14 (c1) shows the pulse width of the voltage vector V0, and FIG. 14 (d1) indicates the transition of the command voltages Vuc, Vvc, Vwc. Since the line voltage and the line current are shifted by “30 °” with respect to the phase of the phase voltage, the pulse width of the voltage vector V0 is maximized in the vicinity of the zero cross timing. For this reason, it is possible to secure a sufficient time for detecting the line current and the polarity of the change amount.

  In contrast, FIGS. 14 (a2) to 14 (d2) show a case where the zero cross timing is detected using the phase current. In this case, the pulse width of the voltage vector V0 is substantially zero near the zero cross timing. For this reason, it is impossible to appropriately detect the polarity of the phase current and the amount of change.

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

  (1) The switching elements SW <b> 1 to SW <b> 6 of the inverter 12 are operated based on the line-to-line current and the zero cross timing of the amount of change. Thereby, even when the modulation rate is high, a sufficient period for detecting the line-to-line current and the amount of change in the line-to-line current can be secured, so that the controllability can be kept high regardless of the modulation rate. .

  (2) The time difference between the zero cross timing of the line current and the zero cross timing of the change amount of the line current is feedback-controlled to zero. Thereby, torque maximization control for generating the maximum torque with the minimum current can be performed.

  (3) The phase of the change in the amount of change in the line current is made to coincide with the phase of the line current. Thereby, the phase of the induced voltage between the lines and the phase of the line current can be matched.

  (4) The phase φ of the command voltages Vuc1, Vvc1, and Vwc1 is variably set based on the time difference ΔΦ between the zero cross timing of the line current and the zero cross timing of the change amount of the line current. Thereby, the zero cross timing of the line current and the zero cross timing of the amount of change of the line current can be suitably matched.

  (5) The command voltages Vuc1, Vvc1, and Vwc1 were subjected to two-phase modulation processing. Thereby, the voltage vector V0 period can be extended, and by extension, the zero cross timing of the amount of change in the line current can be detected with high accuracy. Further, by performing the two-phase modulation process, the upper limit value of the amplitude Vm of the command voltages Vuc1, Vvc1, and Vwc1 can be expanded as compared with the case where the two-phase modulation process is not performed, thereby improving the voltage utilization rate. Can be made.

  (6) Based on the voltage drop amounts ru, rv, rw due to the shunt resistors Ru, Rv, Rw connected between the respective phases of the lower arm of the inverter 12 and the negative input terminal of the inverter 12, the line current and its change The amount was detected. As a result, the line-to-line current and the amount of change thereof can be detected with a simple hardware configuration.

  (7) The line current and the amount of change were detected within the voltage vector V0 period. Thus, based on the voltage drop amounts ru, rv, rw due to the shunt resistors Ru, Rv, Rw connected between each phase of the lower arm and the negative input terminal of the inverter 12, zero crossing within one rotation period of the electrical angle. Timing can be detected six times.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, the command voltages Vuc1, Vvc1, and Vwc1 are determined based on the time difference ΔΦ between the zero-cross timing Φ (I = 0) of the line current and the zero-cross timing Φ (dI / dt = 0) of the amount of change in the line current. The electrical angular velocity ω is variably set. FIG. 15 shows a method for setting the electrical angular velocity ω according to this embodiment. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example. In FIG. 15, the same steps as those shown in FIG. 11 are given the same step numbers for the sake of convenience.

  In this series of processes, when the process of step S42 is completed, the process proceeds to step S44a. In step S44a, the electrical angular velocity ω of the command voltages Vuc1, Vvc1, Vwc1 is set. Here, the electrical angular velocity ω may be set by proportional integration calculation of the time difference ΔΦ. As a result, when the zero cross timing Φ (I = 0) of the line current is delayed from the zero cross timing Φ (dI / dt = 0) of the change amount of the line current, the electrical angular velocity ω is increased. When the zero cross timing Φ (I = 0) of the line current is ahead of the zero cross timing Φ (dI / dt = 0) of the change in the line current, the electrical angular velocity ω is decreased.

  According to this embodiment described above, in addition to the effects (1) to (3) and (5) to (7) of the first embodiment, the following effects can be obtained. .

  (8) The electrical angular velocity ω of the command voltages Vuc1, Vvc1, and Vwc1 is variably set based on the time difference ΔΦ between the zero cross timing of the line current and the zero cross timing of the change amount of the line current. Thereby, the zero cross timing of the line current and the zero cross timing of the amount of change of the line current can be suitably matched.

(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 command voltages Vuc1, Vvc1, and Vwc1 are determined based on the time difference ΔΦ between the zero-cross timing Φ (I = 0) of the line current and the zero-cross timing Φ (dI / dt = 0) of the amount of change in the line current. The amplitude Vm is variably set. FIG. 16 shows a method for setting the electrical angular velocity ω according to this embodiment. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example. In FIG. 16, the same steps as those shown in FIG. 11 are given the same step numbers for the sake of convenience.

  In this series of processes, when the process of step S42 is completed, the process proceeds to step S44b. In step S44b, amplitude values Vm of command voltages Vuc1, Vvc1, and Vwc1 are set. Here, the amplitude Vm may be set by the proportional integration calculation of the time difference ΔΦ. As a result, when the zero cross timing Φ (I = 0) of the line current is delayed from the zero cross timing Φ (dI / dt = 0) of the change amount of the line current, the amplitude Vm is increased. When the zero-cross timing Φ (I = 0) of the line current is ahead of the zero-cross timing Φ (dI / dt = 0) of the change amount of the line current, the amplitude Vm is decreased.

  In addition, when the process of step S44b is completed, this series of processes is once complete | finished.

  According to this embodiment described above, in addition to the effects (1) to (3) and (5) to (7) of the first embodiment, the following effects can be obtained. .

  (9) The amplitudes Vm of the command voltages Vuc1, Vvc1, and Vwc1 are variably set based on the time difference ΔΦ between the zero cross timing of the line current and the zero cross timing of the change amount of the line current. Thereby, the zero cross timing of the line current and the zero cross timing of the amount of change of the line current can be suitably matched.

(Fourth embodiment)
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 17 shows processing related to generation of operation signals of the switching elements SW1 to SW6 among the processing performed by the control device 20 according to the present embodiment. In FIG. 17, processes corresponding to the processes shown in FIG. 2 are given the same reference numerals for convenience.

  In the present embodiment, a rotation speed calculation unit 50 is provided. The rotation speed calculation unit 50 calculates the electrical angular velocity ω of the electric motor 10 based on the polarity reversal period of the change in the line current detected by the change polarity detection unit 44. Then, the speed deviation calculation unit 52 calculates a difference Δω of the command value ωd with respect to the calculated electrical angular velocity ω and outputs the difference Δω to the amplitude setting unit 30. The amplitude setting unit 30 calculates the amplitude Vm based on the difference Δω. Here, the amplitude Vm may be calculated based on the proportional integration calculation of the difference Δω.

  According to this embodiment described above, in addition to the effects (1) to (7) of the first embodiment, the following effects can be obtained.

  (10) The electrical angular velocity ω of the electric motor 10 is calculated based on the time interval between the zero cross timings of the change amount of the line current, and the electrical angular velocity ω is feedback-controlled to the command value ωd. As a result, the electrical angular velocity ω can be appropriately controlled to the command value ωd.

  (11) The feedback control can be performed simply and appropriately by variably setting the amplitude Vm of the command voltages Vuc1, Vvc1, and Vwc1 based on the difference Δω between the electrical angular velocity ω and the command value ωd.

(Fifth embodiment)
Hereinafter, a fifth embodiment will be described with reference to the drawings, focusing on differences from the first embodiment.

  In the present embodiment, the line-to-line current and the amount of change thereof are detected in the periods of the odd voltage vectors V1, V3, and V5 across the voltage vector V0. In this case, the two phases of the electric motor 10 are short-circuited. FIG. 18 shows an equivalent circuit of the electric motor 10 and the like in the voltage vector V1 period. As illustrated, in this case, there is no influence of the voltage VB of the battery 14 between the shorted VW phases, and only the induced voltages eV and eW are used as voltage sources. The relationship between these VW phases at this time is defined by the following formula (c5).

R × (Iv−Iw) + L (dIv / dt−dIw / dt) + (eV−eW) = 0
That is,
R × Ivw + L (dIvw / dt) + eVW = 0 (d5)
This equation is the same as the above equation (c3). Therefore, the same control as that in the first embodiment can be performed by detecting the line current and the amount of change in the odd voltage vectors V1, V3, and V5.

  FIG. 19 illustrates a detection processing mode such as a change amount of the line current according to the present embodiment. FIG. 19A to FIG. 19E show the detection mode of the line current and the like at the timing surrounded by the broken line in the diagram shown on the left side of FIG. Specifically, FIG. 19A shows the duty signals Du, Dv, and Dw, FIG. 19B shows the transition of the operation signals gun, gvn, and gwn, and FIG. 19C shows the transition of the voltage vector. FIG. 19D shows the induced voltage, and FIG. 19E shows the transition of the current in each phase.

  As shown in the figure, in the present embodiment, the current values I1, I2, I3, and I4 are detected in the odd voltage vector periods on both sides of the voltage vector V0, and compared with the case where the current values I1, I2, I3, and I4 are detected. Thus, the interval between the detection timings of the current values I1 and I2 and the current values I3 and I4 can be extended.

  FIG. 20 (a1) to FIG. 20 (d1) show the transition of the odd pulse width. 20A1 to 20D1 correspond to the previous FIG. 14A1 to FIG. 14D1. For comparison, FIGS. 20 (a2) to 20 (d2) show FIGS. 14 (a1) to 14 (d1). As shown in the figure, in this embodiment, the interval between the detection periods of the line current and the amount of change thereof can be made longer than that in the first embodiment.

  However, in this case, although the zero cross timing of the line current at the timing at which the two phases of the duty signals Du, Dv, Dw intersect with each other can be detected, the duty signal Du, Dv, Dw This cannot be detected for the zero cross timing of the line current at the timing when the two phases are positive. For this reason, the zero cross timing can be detected only three times during the control in which the power factor is “1”.

  According to this embodiment described above, the following effects can be obtained in addition to the effects (1) to (6) of the first embodiment.

  (12) The line current and the amount of change thereof were detected when any two phases on both sides across the time when all phases of the electric motor 10 were short-circuited. As a result, the period during which detection is possible can be lengthened as compared to the case where the line current and the amount of change thereof are detected during the voltage vector V0 period.

(Sixth embodiment)
Hereinafter, the sixth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, whether to use the voltage vector V0 period or the odd voltage vector V1, V3, V5 periods on both sides thereof as the detection period of the line current and its change amount is determined based on the duty signal Du, Dv, Dw. Switching is performed according to the value (the amplitudes of the command voltages Vuc, Vvc, Vwc after two-phase modulation). This is because, as shown in FIG. 21, the voltage vector V0 period is shortened as the values (modulation rates) of the duty signals Du, Dv, Dw are increased. On the other hand, as described above, the detectable frequency of the zero cross timing in the odd voltage vector period is halved compared to that of the voltage vector V0. For this reason, the current is detected in the periods of the odd voltage vectors V1, V3, and V5 only when the modulation rate is equal to or higher than a predetermined value. Incidentally, FIG. 22 shows the relationship of the voltage vector period (pulse width) for each electrical angle. As shown in the figure, the pulse width is different for each electrical angle. For this reason, FIG. 21 shows the pulse width at the zero-cross timing.

  According to this embodiment described above, the following effects can be obtained in addition to the effects (1) to (6) of the first embodiment.

  (13) The timing for detecting the line current and its change amount is switched between the voltage vector V0 period and the odd voltage vectors V1, V3, and V5 periods according to the values of the duty signals Du, Dv, and Dw. It was. Thereby, the detection accuracy of the zero crossing timing of the amount of change in the line current can be maintained high regardless of the magnitude of the amplitude.

(Seventh embodiment)
Hereinafter, the seventh embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In FIG. 23, the whole structure of the control system of the electric motor 10 concerning this embodiment is shown. In FIG. 23, members corresponding to those in FIG. In this embodiment, not only the shunt resistances Run, Rvn, Rwn between the negative input terminal of the inverter 12 and the switching elements SW2, SW4, SW6, but also between the positive input terminal of the inverter 12 and the switching elements SW1, SW3, SW5. Shunt resistors Rup, Rvp, and Rwp are provided. Then, the detection of the line current and its change amount is switched between the shunt resistors Run, Rvn, and Rwn or the shunt resistors Rup, Rvp, and Rwp. This is due to the following reason.

  FIG. 24 shows the relationship between the total period (pulse width) of the voltage vector V0 and the odd voltage vectors on both sides thereof and the even voltage vector period (pulse width). As shown in the figure, although the total period of the voltage vector V0 and the odd-numbered voltage vectors on both sides thereof is longer than the period of the voltage vector V0, the period is longer and shorter than the even-numbered voltage vector period with a period of “60 °”. Is reversed. For this reason, in this embodiment, in order to lengthen the detectable period of the line current and the amount of change thereof, in the present embodiment, the line current and the amount of change thereof are detected by the voltage drop amount run, shunt resistances Run, Rvn, Rwn. Switching is performed based on rvn, rwn, or based on voltage drop amounts rup, rvp, rwp of the shunt resistors Rup, Rvp, Rwp as the electrical angle changes.

  FIG. 25 shows the procedure of the switching process. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processes, first, in step S50, among the duty signals Du, Dv, and Dw, the difference between the one having the maximum value and the one having the intermediate value is changed to the one having the intermediate value and the minimum value. It is determined whether or not the difference is greater than the difference. This process is for determining which of the odd voltage vector period and the even voltage vector period is longer. When it is determined that the difference between the one having the maximum value and the one having the intermediate value is larger, it is considered that the odd voltage vector period is longer. Therefore, in step S52, the shunt resistor Run, Based on the voltage drop amounts run, rvn, rwn of Rvn, Rwn, the line current and its change are detected in the total period of the voltage vector V0 and the odd voltage vectors on both sides thereof. On the other hand, when a negative determination is made in step S50, it is determined that the even voltage vector period is longer. Therefore, in step S54, based on the voltage drop amounts rup, rvp, rwp of the shunt resistors Rup, Rvp, Rwp. The line current and its change are detected in the even voltage vector period.

  According to this embodiment described above, the following effects can be obtained in addition to the effects (1) to (6) of the first embodiment.

  (14) The line current and the amount of change thereof are detected based on the voltage drop amounts run, rvn, rwn of the shunt resistors Run, Rvn, Rwn, or the voltage drop amounts rup, rvp, Rwp of the shunt resistors Rup, Rvp, Rwp, Switching based on rwp was switched according to the change in electrical angle. Thereby, a suitable period can be ensured as a detectable period of the line-to-line current and its change amount.

(Eighth embodiment)
Hereinafter, the eighth embodiment will be described with reference to the drawings with a focus on differences from the previous seventh embodiment.

  In the present embodiment, the detection of the line current and the amount of change thereof is performed based on the voltage drop amounts run, rvn, rwn of the shunt resistors Run, Rvn, Rwn, or the voltage drop amounts rup, Rwp of the shunt resistors Rup, Rvp, Rwp. The two-phase modulation processing is also changed depending on whether it is performed based on rvp and rwp. FIG. 26 shows a processing procedure relating to switching of the two-phase modulation processing mode according to the present embodiment. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processes, first, in step S60, among the duty signals Du1, Dv1, and Dw1, the difference between the one having the maximum value and the one having the intermediate value is changed to the one having the intermediate value and the minimum value. It is determined whether or not the difference is greater than the difference. This process is for determining which of the odd voltage vector period and the even voltage vector period is longer. When it is determined that the difference between the one having the maximum value and the one having the intermediate value is longer, the odd voltage vector period is considered to be longer, and the process proceeds to step S62. In step S62, similarly to the process shown in FIG. 3, the two-phase modulation process is performed by shifting the battery 14 to the negative side potential. In the subsequent step S64, the line current and its change are detected in the total period of the voltage vector V0 and the odd-numbered vectors on both sides thereof, as in step S52 of FIG.

  On the other hand, when a negative determination is made in step S60, since the even voltage vector period is considered to be longer, the process proceeds to step S66. In step S66, a two-phase modulation process is performed by shifting the battery 14 to the positive potential. That is, while maintaining the difference between the two phases of the command voltages Vuc 1, Vvc 1, Vwc 1, correction is performed so that the maximum voltage is raised to the positive input terminal potential of the inverter 12. In step S68, the line current and its change are detected in the total period of the voltage vector V7 and the even vectors on both sides thereof.

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

  (15) The line current and the amount of change thereof are detected based on the voltage drop amounts run, rvn, rwn of the shunt resistors Run, Rvn, Rwn, or the voltage drop amounts rup, rvp, Rwp of the shunt resistors Rup, Rvp, Rwp, The two-phase modulation process was also changed depending on whether it was performed based on rwp. As a result, when the line current and the amount of change thereof are detected using the total period of the voltage vector V0 and the odd number vectors on both sides of the voltage vector V0, the synchronization period can be extended, and the voltage vector V7 and the even number vectors on both sides thereof can be expanded. When detecting the line-to-line current and its change amount using the total period, the synchronization period can be extended.

(Ninth embodiment)
Hereinafter, the ninth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, maximum efficiency control is performed instead of maximum torque control. FIG. 27 shows a procedure of processing performed by the phase setting unit 34 shown in FIG. 2 in the present embodiment. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example. In FIG. 27, processes corresponding to the processes shown in FIG. 11 are given the same step numbers for convenience.

  In this series of processes, when the process of step S42 is completed, the process proceeds to step S70. In step S70, the electrical angular velocity ω of the electric motor 10 is calculated based on the inversion cycle of the change polarity of the line current. In the subsequent step S72, a target time difference ΔΦt is calculated based on the electrical angular velocity ω. In this process, a phase difference appropriate for maximum efficiency control is set as a time interval. That is, the time difference ΔΦ between the zero-cross timing Φ (I = 0) of the line current and the zero-cross timing Φ (dI / dt = 0) of the change amount of the line current is equal to the electrical angular velocity ω even if the phase difference is the same. Depending on the time interval. For this reason, the target time difference ΔΦt is set according to the electrical angular velocity ω. In subsequent step S74, the phase φ of the command voltages Vuc1, Vvc1, Vwc1 is calculated based on the difference of the target time difference ΔΦt with respect to the time difference ΔΦ. Here, the phase φ is calculated based on the proportional integration calculation of the target time difference ΔΦt with respect to the time difference ΔΦ.

  According to this embodiment described above, in addition to the effects (1) and (2) to (7) of the first embodiment, the following effects can be obtained.

  (16) A target value (target time difference ΔΦt) of the time difference ΔΦ is set based on the calculated electrical angular velocity ω. Thereby, the target time difference ΔΦt can be appropriately defined.

(Tenth embodiment)
Hereinafter, the tenth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 28 shows processing related to generation of operation signals of the switching elements SW1 to SW6 among the processing performed by the control device 20. In FIG. 28, processes corresponding to those in FIG. 2 are given the same reference numerals for convenience.

  As illustrated, the present embodiment includes a current vector norm calculation unit 60 that calculates the length of a vector of current flowing through the electric motor 10 according to the voltage drop amounts ru, rv, and rw. For example, the current on the α axis and the current on the β axis are calculated from two of the voltage drop amounts ru, rv, and rw, and the length of the vector generated by the current component on each axis is calculated. Can be done. The calculated current vector norm NI is filtered by the high pass filter 62. The high pass filter 62 transmits only a signal having a frequency higher than the electrical angular velocity of the electric motor 10. Here, it is more desirable that the transmission frequency can be variably set according to the speed command value ωd. The output of the high pass filter 62 is taken into the correction amount calculation unit 64. The correction amount calculation unit 64 calculates the correction amount Δφ of the phase φ of the command voltages Vuc1, Vvc1, and Vwc1 according to the output of the high-pass filter 62, that is, the high-frequency component of the change in the amplitude of the current flowing through the motor 10. Then, the phase correction unit 66 corrects the phase φ set by the phase setting unit 34 with the correction amount Δφ.

  As a result, the phase φ can be controlled even in the period between the zero cross timings. That is, as shown in FIG. 29, since the amplitude of the current changes in accordance with the phase of the current, the output of the high-pass filter 62 contains information related to a sudden change in the phase of the electric motor 10. Therefore, by correcting the phase φ based on this, even when the phase of the current flowing through the electric motor 10 changes suddenly, this can be suppressed.

  When the phase φ is changed by the phase setting unit 34, the transmission frequency of the high-pass filter 62 is set to a sufficiently high value so that the correction is not canceled out by the correction amount Δφ. Thereby, the change in the amplitude of the current due to the phase change by the phase setting unit 34 does not completely pass through the high-pass filter 62. Therefore, the interference between the phase setting by the phase setting unit 34 and the correction amount Δφ is preferably performed. Can be suppressed.

  According to this embodiment described above, in addition to the effects (1) to (7) of the first embodiment, the following effects can be obtained.

  (17) The phase φ of the command voltages Vuc1, Vvc1, and Vwc1 is corrected based on a higher frequency component than the electrical angular velocity of the electric motor 10 with respect to the amount of change in current amplitude. Thereby, the change of the phase can be grasped according to the change of the amplitude of the current, and the phase of the electric motor 10 can be controlled even in the period between the zero cross timings.

(Eleventh embodiment)
Hereinafter, the eleventh embodiment will be described with reference to the drawings, centering on differences from the first embodiment.

  FIG. 30 shows a procedure of processing performed by the polarity detection unit 42 and the change polarity detection unit 44 according to the present embodiment. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example. In FIG. 30, processes corresponding to the processes shown in FIG. 10 are given the same step numbers for convenience.

  In this series of processes, when the corresponding two-phase line current I (n-1) at the start of the voltage vector V0 is detected in step S24, the corresponding two-phase line current I of the corresponding two-phase line I is detected in step S80. Perform time integration. In step S82, the time integration calculation of the line current I (n-1) detected in step S24 is performed. The processes in steps S80 and S82 are performed up to near the end timing Tf of the voltage vector V0 (step S26). When it is determined in step S26 that the specified time is a predetermined time α before the end timing Tf of the voltage vector V0, the line current I (n−1) detected in step S30a is determined in step S30a. The polarity of the line-to-line current is calculated as In the following step S32a, the polarity of the change amount of the line current is calculated as a sign of the difference between the time integral value of the line current and the time integral value of the line current I (n-1) within the specified time.

  According to this embodiment described above, in addition to the effects (1) to (7) of the first embodiment, the following effects can be obtained.

  (18) The polarity of the amount of change in the line current based on the difference between the product of the line current I (n-1) and the time interval at the start point of the time interval with respect to the integral value IntI1 at the predetermined time interval of the line current. Was detected. Thereby, when detecting the polarity of the change amount of the line current, it is possible to suitably suppress the influence of noise mixed in the line current.

(Twelfth embodiment)
Hereinafter, the twelfth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, the electric motor 10 is applied to a three-phase rotating machine of an in-vehicle cooling fan. In this case, when the traveling speed of the vehicle increases and the speed of the airflow acting on the cooling fan increases, a phenomenon occurs in which the cooling fan is rotated by a mechanical external force. In this case, the electric motor 10 functions as a generator that converts mechanical energy from the outside into electric energy instead of functioning as an electric motor by supplying electric energy from the battery 14. In this case, if the phase φ is operated in the manner shown in the first embodiment in order to reduce the deviation between the zero cross timing of the amount of change in the line current and the zero cross timing of the line current, These zero cross timings cannot be matched. Hereinafter, this will be described with reference to FIG.

  FIG. 31 shows changes in induced voltage, line-to-line current, etc. during powering control and regenerative control. Here, regarding the line current, the behavior in the zero vector period is indicated by a solid line, and the behavior in other periods is indicated by a broken line.

  As shown in the figure, the relationship between the induced voltage and the line current is different between the power running control and the regenerative control. In other words, the relationship between the amount of change in the line current and the line current is different between the power running control and the regeneration control. For this reason, if the operation of the phase φ exemplified in the first embodiment is performed to execute the maximum torque control for matching the zero cross timing of the line current and the zero cross timing of the change amount, the motor 10 At the time of regenerative control rotated by an external force, the zero cross timing cannot be matched.

  Specifically, as shown below in the figure, at the time of powering control, when the phase of the current vector is advanced with respect to the induced voltage vector on the dq axis, by performing an operation of delaying the phase of the voltage vector, The induced voltage vector and the current vector can be matched. On the other hand, at the time of regenerative control, if the phase of the current vector is advanced with respect to the induced voltage vector on the dq axis, the induced voltage vector and the current vector are matched by performing an operation to advance the phase of the voltage vector. be able to. For this reason, if the same operation is performed during power running control and during regenerative control, maximum torque control cannot be performed in both controls.

  Therefore, in the present embodiment, it is determined whether the control is during power running control or regenerative control, and the operation mode of the command voltage is made variable according to these. Here, first, a method for discriminating between power running control and regenerative control according to the present embodiment will be described with reference to FIG.

  As shown in the figure, at the time of powering control, the phase current of the remaining one phase (here, the W phase is exemplified) at the zero-cross timing of the fall of the line induced voltage (here, the UV phase line induced voltage is exemplified) The polarity of is negative. On the other hand, at the time of regenerative control, the polarity of the remaining one-phase current is positive at the zero cross timing of the fall of the line induced voltage. Thus, the polarity of the remaining one-phase phase current at the zero-crossing timing of the line induced voltage is opposite between the power running control and the regenerative control. Can be identified. Here, in the present embodiment, it is assumed that the motor 10 is driven in a region where the rotational speed of the motor 10 is greater than or equal to a predetermined value, in other words, a region where the induced voltage becomes significant. For this reason, in the relationship of the above formula (c3), the term of the line current is negligible compared to the induced voltage, so that the polarity of the variation near the zero cross timing is opposite to the polarity of the induced voltage near the zero cross timing. It is thought that it becomes. For this reason, it is possible to identify whether it is the power running control or the regenerative control based on the polarity of the phase current at the rising zero cross timing or the falling zero cross timing.

  FIG. 33 shows processing relating to generation of operation signals of the switching elements SW1 to SW6 according to the present embodiment. In FIG. 33, processes corresponding to the processes shown in FIG. 2 are given the same reference numerals for the sake of convenience.

  As shown in the figure, in the present embodiment, whether the power running control or the regenerative control is performed based on the polarity of the phase current with the voltage drop amounts ru, rv, rw of the shunt resistors Ru, Rv, Rw as inputs. The drive state detection part 70 which judges these is provided. Then, the phase setting unit 34 sets the phase φ based on the determination result of the drive state detection unit 70. FIG. 34 shows the procedure of the phase φ setting process according to this embodiment. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processing, first, in step S90, it is determined whether or not it is the polarity reversal timing of the change amount of the line current. This process is for determining whether the power running control or the regenerative control is being performed based on the polarity of the phase current. When it is determined that it is the inversion timing, it is determined in step S92 whether or not the change amount is inverted from negative to positive. This process determines whether or not the polarity of the line induced voltage is reversed from positive to negative. That is, in the present embodiment, as described above, the zero cross timing of the amount of change in the line current and the zero cross timing of the line induced voltage are approximated to each other because of driving the motor 10 at a rotational speed greater than or equal to a predetermined speed. The polarities before and after are considered to be opposite to each other. For this reason, it is possible to determine whether or not it is the falling zero cross timing at which the line induced voltage is inverted from positive to negative based on the polarity before and after the zero cross timing of the amount of change in the line current.

  In a succeeding step S94, it is determined whether or not the remaining one-phase current is negative. This process is for determining whether or not it is during power running control. On the other hand, when a negative determination is made in step S92, it is determined whether or not the remaining one-phase current is positive. This process is also for determining whether or not it is during power running control. That is, when a negative determination is made in step S92, the remaining one-phase current is positive during powering control because it is in the vicinity of the rising zero cross timing of the induced voltage.

  If an affirmative determination is made in steps S94 and S96, it is determined in step S98 that the power running control is in progress. On the other hand, when a negative determination is made in steps S94 and S96, it is determined in step S100 that the regenerative control is being performed. If it is determined that the regenerative control is being performed, the sign of the gains Kp and Ki for setting the phase φ of the command voltage is reversed with respect to that during the power running control in step S102. Then, when the process of step S102 or the process of step S98 is completed, the phase φ is set in step S104.

  When a negative determination is made in step S90 or when the process of step S104 is completed, this series of processes is temporarily terminated.

  FIG. 35 shows an aspect of the above processing during power running control. As shown in the figure, when the zero cross timing of the line current is delayed with respect to the zero cross timing of the change amount of the line current, the phase φ of the command voltage is advanced. On the other hand, when the zero cross timing of the line current is advanced with respect to the zero cross timing of the change amount of the line current, the phase φ of the command voltage is delayed.

  On the other hand, FIG. 36 shows an aspect of the above processing at the time of regeneration control. As shown in the figure, when the zero cross timing of the line current advances with respect to the zero cross timing of the change amount of the line current, the command voltage phase φ is advanced. On the other hand, when the zero cross timing of the line current is delayed with respect to the zero cross timing of the change amount of the line current, the phase φ of the command voltage is retarded.

  According to this embodiment described above, in addition to the effects (1) to (7) of the first embodiment, the following effects can be obtained.

  (19) In setting the command voltage, the determination result as to whether the electric motor 10 is in powering control or regenerative control is taken into account. Thereby, it is possible to appropriately set the command voltage in both the power running control and the regenerative control.

  (20) During power running control, set the command voltage phase φ to advance so that the zero cross timing of the line current shifts to the lag side with respect to the zero cross timing of the change amount, and at the zero cross timing of the change amount during regenerative control. On the other hand, the phase φ of the command voltage is set to be delayed as the zero cross timing of the line current shifts to the delay side. Also, during power running control, the command voltage phase φ is set to be delayed so that the zero cross timing of the line current shifts to the advance side with respect to the zero cross timing of the change amount. Thus, the command voltage phase φ is set to advance so that the zero cross timing of the line current shifts to the advance side. Thereby, a command voltage can be operated appropriately.

  (21) Based on the change polarity of the amount of change (rising and rising of the induced voltage) and the polarity of the phase current of the remaining phase, it was determined whether it was powering control or regenerative control. Thereby, power running control and regeneration control can be distinguished exactly.

  (22) Based on the change polarity at the time of the zero cross timing of the change amount and the polarity of the phase current, it was determined whether it was powering control time or regenerative control time. Thereby, power running control and regeneration control can be distinguished more appropriately.

(13th Embodiment)
Hereinafter, the thirteenth embodiment will be described with reference to the drawings, centering on differences from the previous twelfth embodiment.

  FIG. 37 shows a procedure of command voltage setting processing according to the present embodiment. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example. In FIG. 37, processes similar to those shown in FIG. 34 are given the same reference numerals for convenience.

  In this series of processes, when it is determined in step S100 that the regenerative control is being performed, in step S102a, the signs of the gains Kp and Ki for setting the angular velocity ω are reversed with respect to those in the powering control. Then, when the process of step S102a or the process of step S98 is completed, the angular velocity ω is set in step S104a.

  As a result, the angular velocity ω of the command voltage is increased during powering control and the angular velocity ω of the command voltage is reduced during regenerative control as the zero-cross timing of the line current is shifted to the lag side with respect to the zero-cross timing of the change amount. Become. Also, the more the zero cross timing of the line current shifts to the advance side with respect to the zero cross timing of the change amount, the angular velocity ω of the command voltage is reduced during power running control, and the angular velocity ω of the command voltage is increased during regenerative control. . Thereby, a command voltage can be operated appropriately.

  According to the present embodiment described above, an effect according to the effects of the second embodiment and the twelfth embodiment can be obtained.

(Fourteenth embodiment)
The fourteenth embodiment will be described below with reference to the drawings, centering on differences from the previous twelfth embodiment.

  FIG. 38 shows a procedure of command voltage setting processing according to the present embodiment. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example. In FIG. 38, the same processes as those shown in FIG. 34 are given the same reference numerals for the sake of convenience.

  In this series of processes, when it is determined in step S100 that the regenerative control is being performed, in steps S102b, the signs of the gains Kp and Ki for setting the amplitude Vm are reversed from those in the powering control. When the process of step S102b or the process of step S98 is completed, the amplitude Vm is set in step S104b.

  As a result, the amplitude Vm of the command voltage is increased during powering control and the amplitude Vm of the command voltage is reduced during regenerative control as the zero cross timing of the line current is shifted toward the delay side with respect to the zero cross timing of the change amount. Become. Further, the more the zero cross timing of the line current shifts to the advance side with respect to the zero cross timing of the change amount, the amplitude Vm of the command voltage is reduced during the power running control, and the amplitude Vm of the command voltage is increased during the regeneration control. . Thereby, a command voltage can be operated appropriately.

  According to the present embodiment described above, an effect according to the effects of the third embodiment and the twelfth embodiment can be obtained.

(Fifteenth embodiment)
The fifteenth embodiment will be described below with reference to the drawings, centering on differences from the previous twelfth embodiment.

  In this embodiment, as described in Patent Document 1, maximum torque control is performed by matching the zero-cross timing of the phase current with the zero-cross timing of the amount of change in the phase current. In other words, the maximum torque control is performed by matching the zero cross timing of the phase current with the zero cross timing of the phase induced voltage. However, even in this case, if the operation of the command voltage when the phase current zero cross timing and the phase current change zero cross timing are different between the power running control and the regenerative control, The maximum torque control cannot be performed properly. For this reason, the operation mode of the command voltage is made variable according to whether it is power running control or regenerative control.

  FIG. 39 shows a method for discriminating between power running control and regenerative control according to the present embodiment. As shown in the figure, during powering control, the polarity of the remaining two-phase line currents is positive at the zero cross timing of the fall of the phase induced voltage (here, U phase is illustrated). On the other hand, at the time of regenerative control, the polarity of the remaining two-phase line current is negative at the time of zero cross timing of the fall of the phase induced voltage (here, U phase is illustrated). For this reason, for the same reason as in the twelfth embodiment, based on the change polarity of the change amount of the phase current at the zero cross timing and the polarity of the remaining two-phase line-to-line current, It is possible to determine whether it is during regenerative control. Below, the process concerning the setting of the command voltage based on this determination will be described.

  Here, based on FIG. 40, the procedure of the detection process of the polarity of a phase current and its change amount will be described first. In FIG. 40, processing corresponding to the processing shown in FIG. 10 is given the same step number for convenience and description thereof is omitted.

  In this series of processes, when it is determined in step S22 that it is the start time of the voltage vector V0 period, the phase current I (n-1) of the corresponding phase is detected in step S24b. Here, the “corresponding phase” is an electric angle that is switched every “60 °”, and each “60 °” region includes one zero-cross timing. For this reason, the corresponding phase is assumed to be a phase in which zero cross timing is assumed to be included in the region.

  On the other hand, when a positive determination is made in step S26, in step S28b, the phase current I (n) is detected for the same phase as the corresponding phase in step S24b. Then, in steps S30b and S32b, the polarity of the phase current and the polarity of the change amount of the phase current are calculated by the same process as the process of steps S30 and S32 shown in FIG.

  FIG. 41 shows the procedure of the phase φ setting process according to this embodiment. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example. In FIG. 41, the same processes as those shown in FIG. 34 are given the same reference numerals for the sake of convenience.

  In this series of processing, first, in step S90a, it is determined whether or not it is the polarity reversal timing of the change amount of the phase current. This process determines the polarity inversion timing of the phase induced voltage. If it is determined that it is the inversion timing, the same processing as the processing in step S92 of FIG. 34 is performed. If an affirmative determination is made in step S92, it is determined in step S94a whether the remaining two-phase line current is positive. On the other hand, if a negative determination is made in step S92, it is determined in step S96a whether or not the remaining two-phase line current is negative. The processes in steps S94a and S96a are for determining whether or not the power running control is in progress.

  According to such processing, the phase φ is set to the advanced side during the power running control and the phase φ is set to the delayed side during the regenerative control so that the zero cross timing of the phase current shifts to the late side with respect to the zero cross timing of the phase current change amount. Will be set. In addition, the phase φ is set to the lag side during power running control, and the phase φ is set to the lead side during regenerative control, as the zero cross timing of the phase current shifts toward the advance side with respect to the zero cross timing of the phase current change amount. It becomes.

  According to the present embodiment described above, an effect according to the effect of the previous twelfth embodiment can be obtained.

(Sixteenth embodiment)
Hereinafter, the sixteenth embodiment will be described with reference to the drawings with a focus on differences from the fifteenth embodiment.

  FIG. 42 shows a procedure of command voltage setting processing according to the present embodiment. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example. In FIG. 42, the same processes as those shown in FIGS. 42 and 37 are given the same reference numerals for the sake of convenience.

  In this series of processes, when it is determined in step S100 that the regenerative control is being performed, in step S102a, the signs of the gains Kp and Ki for setting the angular velocity ω are reversed with respect to those in the powering control. Then, when the process of step S102a or the process of step S98 is completed, the angular velocity ω is set in step S104a.

  As a result, the angular velocity ω of the command voltage is increased during powering control and the angular velocity ω of the command voltage is reduced during regenerative control as the zero cross timing of the phase current is shifted to the lag side with respect to the zero cross timing of the change amount. . Further, as the zero cross timing of the phase current is shifted to the advance side with respect to the zero cross timing of the change amount, the angular speed ω of the command voltage is reduced during power running control, and the angular velocity ω of the command voltage is increased during regenerative control. Thereby, a command voltage can be operated appropriately.

  According to the present embodiment described above, an effect according to the effect of the previous thirteenth embodiment can be obtained.

(Seventeenth embodiment)
The seventeenth embodiment will be described below with reference to the drawings with a focus on differences from the previous fourteenth embodiment.

  FIG. 43 shows a procedure of command voltage setting processing according to the present embodiment. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example. In FIG. 43, processes similar to those shown in FIGS. 38 and 41 are given the same reference numerals for convenience.

  In this series of processes, when it is determined in step S100 that the regenerative control is being performed, in steps S102b, the signs of the gains Kp and Ki for setting the amplitude Vm are reversed from those in the powering control. When the process of step S102b or the process of step S98 is completed, the amplitude Vm is set in step S104b.

  As a result, the amplitude Vm of the command voltage is increased during powering control and the amplitude Vm of the command voltage is reduced during regenerative control as the zero-cross timing of the phase current is shifted toward the delay side with respect to the zero-cross timing of the change amount. Become. Further, the more the zero cross timing of the phase current is shifted to the advance side with respect to the zero cross timing of the change amount, the amplitude Vm of the command voltage is reduced during power running control, and the amplitude Vm of the command voltage is increased during regenerative control. Thereby, a command voltage can be operated appropriately.

  According to the present embodiment described above, an effect according to the effect of the previous fourteenth embodiment can be obtained.

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

  -You may change 2nd-4th embodiment and 7th-11th embodiment by the change with respect to 1st Embodiment of 5th Embodiment.

  -You may change the 3rd-4th embodiment and the 6th-11th embodiment by the change with respect to 1st Embodiment of 2nd Embodiment.

  -You may change 6th-11th embodiment by the change with respect to 1st Embodiment of 4th Embodiment.

  In the eleventh embodiment, the line current I (n) at the end point of the integration interval may be used instead of the line current I (n-1) at the start point of the integration interval.

  In the fourth embodiment, the amplitude Vm is set to feedback control the rotation speed. However, the present invention is not limited to this. For example, the electrical angular speed ω of the command voltages Vuc1, Vvc1, and Vwc1 may be variably set. Moreover, it is good also as a structure which correct | amends command voltage Vuc1, Vvc1, Vwc1.

  In the sixth embodiment, the command voltage is used as a parameter for determining which of the voltage vector V0 and the odd voltage vector is used. However, the present invention is not limited to this. For example, switching may be performed according to the electrical angle.

  -Based on the zero cross timing of the line current and the zero cross timing of the amount of change in the line current, not only one that variably sets any one of the command voltages Vuc1, Vvc1, Vwc1, but any two or all It may be variably set.

  In the above embodiment, proportional-integral control is used as feedback control in the second to fourth, ninth, and the like, but the present invention is not limited to this, and may be proportional-integral-derivative control, for example.

  In the first to tenth embodiments, the polarity of the line current may be detected as a sign of the difference between the phase currents at any one point.

  The means for changing the command voltages Vuc1, Vvc1, and Vwc1 so as to extend the period during which at least two phases are short-circuited is not limited to the means that performs the two-phase modulation. For example, when the voltage vector V0 period is reached, the voltage vector V0 period may be forcibly held for a minimum time during which the amount of change in current can be detected with high accuracy.

  The method for detecting the change amount of the line current is not limited to the one exemplified in the above embodiments, and for example, an analog differentiation circuit may be used.

  The twelfth to fourteenth embodiments may be changed according to changes in the fourth to seventh (eighth) and ninth to eleventh embodiments with respect to the first embodiment.

  In the twelfth to seventeenth embodiments, proportional-integral control is used as feedback control. However, the present invention is not limited to this, and may be proportional-integral-derivative control, for example.

  In the twelfth to seventeenth embodiments, the maximum torque control is performed. However, the present invention is not limited to this, and maximum efficiency control or the like may be performed. For example, the difference between the zero cross timing of the line current and the zero cross timing of the change amount of the line current, or the difference between the zero cross timing of the phase current and the zero cross timing of the change amount of the phase current is set to the target value (≠ 0). It can be realized by controlling. In this case, the zero cross timing of the change amount is different from the zero cross timing of the induced voltage. For this reason, it is desirable that the target value is adapted so as to be shifted from an appropriate value in performing maximum efficiency control as a difference between the zero cross timing of the induced voltage and the zero cross timing of the current. Thereby, the difference between the zero cross timing of the induced voltage and the zero cross timing of the current can be controlled to an appropriate value for maximum efficiency control.

  In the twelfth to seventeenth embodiments, the remaining one-phase phase current (the remaining two-phase line spacing) at the zero-cross timing of the amount of change in the line current (phase current) correlated with the zero-cross timing of the induced voltage Although the power running control and the regenerative control are identified based on the polarity of the (current), the present invention is not limited to this. For example, identification is performed based on the change polarity of the line current change in the predetermined region and the polarity of the remaining one-phase phase current, or the change polarity of the phase current change in the predetermined region and the polarity of the remaining two-phase line current. May be. That is, for example, as shown in FIG. 32, when the change polarity of the change amount of the line current is positive in the vicinity of the zero cross timing of the induced voltage, the power running is performed if the polarity of the remaining one-phase current is negative. Since it is a control, and if it is positive, it is a regenerative control, the power running control and the regenerative control can be distinguished by paying attention to such a phenomenon.

  -The identification processing between power running control and regenerative control is not limited to the above. For example, a current sensor may be provided on the input terminal side of the inverter 12, and power running control and regenerative control may be distinguished based on the direction of current flow at the input terminal.

  The method for detecting the current flowing through the electric motor 10 is not limited to the method using the voltage drop amount of the shunt resistor shown in FIG. 1 and FIG. For example, as shown in FIG. 44, a technique using voltage drop amounts ru, rv, rw of switching elements connected between the positive input terminal of the inverter 12 and the switching elements SW1, SW3, SW5 may be used. . In this case, it is desirable to update the duty signals Du, Dv, Dw at the timing when the carrier becomes the minimum value. However, the relationship between the update timing of the duty signals Du, Dv, and Dw and the carrier may be arbitrary.

  Further, as shown in FIG. 45, it may be based on the voltage drop amount between the input / output terminals of the switching elements SW2, SW4, SW6. Alternatively, the amount of voltage drop between the input / output terminals of the switching elements SW1, SW3, SW5 may be used. Further, the amount of voltage drop between the input / output terminals of the switching elements SW2, SW4, SW6 and the switching element may be used. The processing as in the seventh and eighth embodiments may be performed by appropriately using both the voltage drop amounts between the input / output terminals of SW1, SW3, and SW5. In particular, when MOS transistors are used as the switching elements SW1 to SW6, the relationship between the voltage drop amount between the input / output terminals (between the drain and source) and the current flowing therethrough is a linear relationship, so that the current can be easily detected. It is. On the other hand, in an insulated gate bipolar transistor (IGBT), for example, the nonlinearity of the relationship between the voltage drop amount between the input / output terminals (between the collector and the emitter) and the current flowing therethrough is strong. However, in the first to tenth embodiments, since only the polarity of the current and the amount of change thereof needs to be detected, there is no particular problem even when the nonlinearity is strong like an IGBT.

  Moreover, as shown in FIG. 46, it is good also as a structure provided with the current sensors 24 and 26 in arbitrary 2 phases (or 3 phases).

  Further, as shown in FIG. 47, the switching elements SW2, SW4, and SW6 are IGBTs having a sense terminal ST, and the current flowing between the input and output terminals of the switching elements SW2, SW4, and SW6 is determined based on the current flowing through the sense terminal ST. It may be detected. Alternatively, only the switching elements SW1, SW3, and SW5 may have a sense terminal. Furthermore, the processing as in the seventh and eighth embodiments may be performed by providing all the switching elements SW to SW6 with sense terminals. The sense terminal is a terminal that outputs a minute current corresponding to the current flowing between the input and output terminals of the switching element.

  Furthermore, a single shunt resistor may be provided on at least one of the positive electrode side input terminal and the negative electrode side input terminal of the inverter 12 and utilized. That is, for example, when a shunt resistor is provided only at the negative side input terminal, the W-phase current is detected during the voltage vector V2 period, and the total value of the V-phase and W-phase currents during the voltage vector V1 period adjacent thereto. Can be detected. Since the W-phase current immediately after switching to the voltage vector V1 period is considered to be substantially equal to the W-phase current in the previous voltage vector V2 period, the current of the V-phase alone can also be calculated from these. Thereby, the line current of the VW phase can be calculated.

  The electric motor 10 is not limited to that provided in the in-vehicle air conditioner, and may be provided in, for example, an in-vehicle cooling fan. Furthermore, the rotating machine is not limited to an electric motor but may be a generator.

The figure which shows the whole structure of the control system of the electric motor concerning 1st Embodiment. The block diagram which shows the processing content of the control apparatus concerning the embodiment. The flowchart which shows the procedure of the two-phase modulation process concerning the embodiment. The time chart which shows the PWM process aspect concerning the embodiment. The time chart which shows the PWM process aspect concerning the embodiment. The figure explaining a voltage vector. The time chart which shows the control aspect of the electric motor concerning this embodiment. The time chart which shows the control aspect of the electric motor concerning this embodiment. The circuit diagram which shows the equivalent circuit of the U phase in the voltage vector V0 period. The flowchart which shows the procedure of the process which detects the polarity of the line current concerning the said embodiment, and its variation | change_quantity. The flowchart which shows the procedure of the setting process of the command voltage concerning the embodiment. The time chart which shows the definition method of the phase difference of the line current concerning the same embodiment, and its variation | change_quantity. The time chart which shows the merit of the two-phase modulation process concerning the embodiment. The time chart which shows the merit which uses the line current concerning the embodiment. The flowchart which shows the procedure of the setting process of the command voltage concerning 2nd Embodiment. The flowchart which shows the procedure of the setting process of the command voltage concerning 3rd Embodiment. The block diagram which shows the processing content of the control apparatus concerning 4th Embodiment. The circuit diagram which shows the equivalent circuit at the time of an odd voltage vector. The time chart which shows the detection method of the line current concerning 5th Embodiment, and its variation | change_quantity. The time chart which shows the merit of the embodiment. The figure which shows the relationship between a modulation rate and pulse widths, such as a zero voltage vector. The time chart which shows the characteristic of two processes used as the switching object of embodiment concerning 6th Embodiment. The figure which shows the whole structure of the control system of the electric motor concerning 7th Embodiment. The time chart explaining the motive of the embodiment. The flowchart which shows the procedure of the switching process concerning the embodiment. The flowchart which shows the procedure of the switching process concerning 8th Embodiment. The flowchart which shows the procedure of the setting process of the command voltage concerning 9th Embodiment. The block diagram which shows the processing content of the control apparatus concerning 10th Embodiment. The figure which shows the relationship between the electric current phase and amplitude which the embodiment uses. The flowchart which shows the procedure of the detection process of the polarity of the line current concerning 11th Embodiment, and its variation | change_quantity. The figure for demonstrating the problem of the said 1st Embodiment. The time chart which shows the identification method of the power running control and regeneration control concerning 12th Embodiment. The block diagram which shows the processing content of the control apparatus concerning the embodiment. The flowchart which shows the procedure of the setting process of the command voltage concerning the embodiment. The figure which shows the aspect of the power running control concerning the embodiment. The figure which shows the aspect of the regeneration control concerning the embodiment. The flowchart which shows the procedure of the setting process of the command voltage concerning 13th Embodiment. The flowchart which shows the procedure of the setting process of the command voltage concerning 14th Embodiment. The time chart which shows the identification method of the power running control and regeneration control concerning 15th Embodiment. The flowchart which shows the procedure of the process which detects the polarity of the phase current concerning the embodiment, and its variation | change_quantity. The flowchart which shows the procedure of the setting process of the command voltage concerning the embodiment. The flowchart which shows the procedure of the setting process of the command voltage concerning 16th Embodiment. The flowchart which shows the procedure of the setting process of the command voltage concerning 17th Embodiment. The figure which shows the whole structure of the control system of the electric motor in the modification of each said embodiment. The figure which shows the whole structure of the control system of the electric motor in the modification of each said embodiment. The figure which shows the whole structure of the control system of the electric motor in the modification of each said embodiment. The figure which shows the whole structure of the control system of the electric motor in the modification of each said embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Electric motor, 12 ... Inverter, 20 ... Control apparatus, 42 ... Polarity detection part, 44 ... Change polarity detection part, 34 ... Phase setting part.

Claims (25)

A current zero-cross detection means for detecting a zero-cross timing of a line current that is a current difference between any two short-circuited when at least two phases of the multi-phase rotating machine are short-circuited;
A change zero-cross detection means for detecting a zero-cross timing of a change amount of the line current of the arbitrary two phases when the at least two phases are short-circuited;
Command voltage setting means for setting a command value of a voltage to be applied to the multiphase rotating machine based on detection values of the current zero cross detection means and the change zero cross detection means;
A control device for a multi-phase rotating machine, comprising: operating means for operating a switching element of a power conversion circuit connected to the multi-phase rotating machine based on the command value.   2. The command voltage setting means sets the command value so as to control a difference between a zero-cross timing of the line current and a zero-cross timing of a change amount of the line current to a target value. Multiphase rotating machine control device. The difference between the two zero-cross timing, the polarity of the zero-cross timing and the line between the current when the polarity of the change amount of the line between the current changes from one of the positive and negative on the other changes to the one from the other 3. The control device for a multi-phase rotating machine according to claim 2, wherein the controller is defined as a difference from the zero cross timing at the time . Speed calculating means for calculating the rotational speed of the multiphase rotating machine based on a time interval between zero cross timings of changes in line current detected by the change zero cross detecting means;
4. The control device for a multi-phase rotating machine according to claim 2, further comprising means for setting the target value of the difference between the zero cross timings based on the calculated rotation speed.   5. The command voltage setting unit variably sets at least one of an amplitude, a phase difference, and an electrical angular velocity of the command value based on a difference between the zero cross timings. The control apparatus of the multiphase rotating machine of description. Speed calculating means for calculating the rotational speed of the multiphase rotating machine based on a time interval between zero cross timings of changes in line current detected by the change zero cross detecting means;
6. The control of a multi-phase rotating machine according to claim 1, further comprising feedback control means for feedback-controlling the calculated rotational speed to a rotational speed command value for the multi-phase rotating machine. apparatus.   The command voltage setting means includes the feedback control means, and sets the voltage command value based on a difference between the calculated rotation speed and a rotation speed command value for the multiphase rotating machine. The control device for a multi-phase rotating machine according to claim 6. The multi-phase rotating machine is a three-phase rotating machine;
The current zero cross detection means and the change zero cross detection means are a high potential side detection means for detecting a current flowing in each phase of the upper arm of the power conversion circuit and a current flowing in each phase of the lower arm of the power conversion circuit. The detection is performed using any detection value of the low potential side detection means to detect, and the timing for performing the detection is when the three phases are short-circuited and when the two phases are short-circuited The control device for a multi-phase rotating machine according to any one of claims 1 to 7, wherein the controller is switched according to an amplitude of a command value of the voltage.   The current zero cross detection means and the change zero cross detection means are a high potential side detection means for detecting a current flowing in each phase of the upper arm of the power conversion circuit and a current flowing in each phase of the lower arm of the power conversion circuit. Whether to use the detection values of both of the low-potential side detection means to detect and which of the high-potential side detection means and the low-potential side detection means to use is determined by the polyphase rotating machine. The control device for a multi-phase rotating machine according to any one of claims 1 to 7, wherein switching is performed in accordance with a change in electrical angle. The voltage difference between one of the pair of input terminals of the power conversion circuit among the command values of the voltage is minimized while maintaining the difference in value between the two phases of the command value of the voltage set by the command voltage setting means. Further comprising two-phase modulation means for matching the voltage to the voltage of any one of the input terminals,
The operation means is for operating the switching element so as to be a command value modulated by the two-phase modulation means,
The two-phase modulation means uses the voltage of the input terminal on the high potential side as the voltage of any one of the input terminals when the current zero cross detection means and the change zero cross detection means use a high potential side detection means, 10. The voltage of the low potential side input terminal is used as the voltage of any one of the input terminals when the current zero cross detection means and the change zero cross detection means use a low potential side detection means. The control apparatus of the multiphase rotating machine of description. The voltage command value set by the command voltage setting means further comprises means for changing the voltage command value so as to extend a period during which the at least two phases are short-circuited,
The control device for a multi-phase rotating machine according to any one of claims 1 to 9, wherein the operating means operates the switching element so as to be the changed command value. The voltage command value that minimizes the difference between one of the pair of input terminals of the power conversion circuit among the voltage command values while maintaining the difference between the two phases of the voltage command value set by the command voltage setting means Further comprising two-phase modulation means for matching the voltage to any one of the voltages,
The control device for a multi-phase rotating machine according to any one of claims 1 to 11, wherein the operating means operates the switching element so as to have a command value modulated by the two-phase modulating means.   The multiphase rotation according to any one of claims 1 to 12, further comprising correction means for correcting the command voltage based on a change in amplitude of a current having a frequency higher than an electrical angular velocity of the multiphase rotating machine. Machine control device. The change zero-cross detection unit is configured such that when the two arbitrary phases are short-circuited, a difference between values of the two-phase line currents at two different sampling timings, and when the two arbitrary phases are short-circuited any of the differential value of the line currents of the two phases, and the start and end points of the integration value and the time interval at a predetermined time interval of the line currents of the two phases when the arbitrary two phases are short-circuited the line current and the difference between the product of the time interval, the controller of the multi-phase rotary machine according to any one of claims 1 to 13, characterized in that performing the detection on the basis of one of the pressurized .   The current zero-cross detection means and the change zero-cross detection means include a shunt resistor connected between each phase of the upper arm of the power conversion circuit and a positive input terminal of the power conversion circuit, and a lower arm of the power conversion circuit 15. The multiphase according to claim 1, wherein the detection is performed based on a voltage drop caused by at least one of a shunt resistor connected between each phase of the power conversion circuit and a negative input terminal of the power conversion circuit. Control device for rotating machine.   The current zero-cross detection means and the change zero-cross detection means are the amount of voltage drop between the input / output terminals of the switching element of the upper arm of the power conversion circuit and the input / output terminals of the switching element of the lower arm of the power conversion circuit. The control device for a multi-phase rotating machine according to claim 1, wherein the detection is performed based on a voltage drop caused by at least one of the voltage drop amounts. The multi-phase rotating machine is a three-phase rotating machine;
The multiphase according to any one of claims 1 to 16, wherein the current zero cross detection means and the change zero cross detection means perform the detection when all phases of the multiphase rotating machine are short-circuited. Control device for rotating machine. The multi-phase rotating machine is a three-phase rotating machine;
The change zero-cross detection means is configured such that the line current in each of a period in which any two phases, which are a pair of periods adjacent in time series in a period in which all phases of the multiphase rotating machine are short-circuited, is short-circuited. The control device for a multi-phase rotating machine according to any one of claims 1 to 16, wherein the detection is performed based on a change amount between them. A judgment means for judging whether the power running control or the regenerative control of the multi-phase rotating machine;
The control device for a multi-phase rotating machine according to any one of claims 1 to 18, wherein the command voltage setting unit takes into account a determination result of the determination unit when setting the command value.   The command voltage setting means variably sets at least one of an amplitude, a phase difference, and an electrical angular velocity of the command value so as to control a difference between the zero cross timings to a target value, and the multiphase rotation 20. The at least one operation direction when the difference between the difference and the target value is the same during power running control and regenerative control of the machine is opposite to each other. Multiphase rotating machine control device.   The command voltage setting means variably sets the phase of the command value to control the difference between the zero cross timing of the line current and the zero cross timing of the change amount to the target value, and during the power running control The phase is advanced so that the difference shifts toward the delay side with respect to the target value.At the time of the regeneration control, the phase is delayed as the difference shifts toward the delay side with respect to the target value. The control device for a multi-phase rotating machine according to claim 20, wherein the controller is set.   The command voltage setting means variably sets the amplitude of the command value to control the difference between the zero cross timing of the line current and the zero cross timing of the change amount to the target value, and during the power running control The amplitude is increased as the difference deviates from the target value, and the amplitude is decreased as the difference deviates from the target value during the regeneration control. The control device for a multi-phase rotating machine according to claim 20 or 21.   The command voltage setting means variably sets the electrical angular velocity of the command value so as to control the difference of the zero cross timing of the line current with respect to the zero cross timing of the change amount to the target value, and the power running control Sometimes, the electrical angular velocity is increased as the difference deviates from the target value, and during the regeneration control, the electric angular velocity is reduced as the difference deviates from the target value. The control device for a multiphase rotating machine according to any one of claims 20 to 22, wherein the control device is a multiphase rotating machine. The multi-phase rotating machine is a three-phase rotating machine,
The said determination means performs the said determination based on the change polarity of the said variation | change_quantity, and the polarity of the phase currents of phases other than the said arbitrary two phases, The any one of Claims 19-23 characterized by the above-mentioned. Control device for multi-phase rotating machine.   25. The control device for a multi-phase rotating machine according to claim 24, wherein the determination means performs the determination based on the change polarity and the polarity of the phase current at the time of zero crossing of the change amount.