JP6451361B2 - Control device for three-phase rotating electric machine - Google Patents

Description

  The present invention relates to a control device for a three-phase rotating electric machine that controls a control amount of the three-phase rotating electric machine by operating an inverter.

  For example, in Patent Document 1, in a region where the rotational speed of a three-phase rotating electrical machine is low, rectangular wave energization is performed with an overlap amount that can detect the induced voltage from the terminal voltage, and in a region where the rotational speed is high, Sensorless processing devices that increase the amount of lap have been proposed. Here, when the overlap amount is increased, the induced voltage cannot be detected from the terminal voltage. Therefore, in this device, in the region where the rotational speed is high, the timing of turning on the switching element of the U-phase upper arm is delayed to detect the induced voltage while reducing the overlap amount.

JP 2010-252406 A

  However, in the above case, the frequency of position detection based on the induced voltage is once in “360 °” in the region where the rotational speed is high, and once in “60 °” which is the frequency of position detection in the region where the rotational speed is low. It becomes low compared with. And if the frequency of position detection becomes low, the tolerance with respect to a rotation fluctuation | variation will fall, and as a result, we are anxious about causing the fall of stability of control.

  The present invention has been made in view of such circumstances, and the purpose thereof is a three-phase rotation capable of achieving a suitable balance between suppressing a decrease in resistance to rotational fluctuation and ensuring an overlap amount. The object is to provide an electric control device.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
1. In the control device for a three-phase rotating electric machine that controls the control amount of the three-phase rotating electric machine by operating the inverter, the inverter includes the voltage source terminals on the high voltage side and the low voltage side of the DC voltage source, and the three-phase rotating electric machine. A plurality of a pair of switching elements for opening and closing between each of the winding terminals, and a pair of the high voltage side and the low voltage side connected to each of the three winding terminals of the three-phase rotating electrical machine Prior to each on-operation of the switching element, detecting a timing at which the phase of the induced voltage of the three-phase rotating electrical machine appearing at a winding terminal connected to the switching element to be turned on becomes a predetermined phase. The rotation angle sensorless processing unit of the three-phase rotating electric machine that executes the process of acquiring the rotation angle information of the three-phase rotating electric machine and the pair of screws at all of the three winding terminals. A first mode in which the overlap amount, which is the length of the energization angle region in which any one of the etching elements is turned on, is zero or more, and a second mode in which the overlap amount is longer than the amount in the first mode A switching processing unit that switches between the second mode and the first mode when the absolute value of the electrical angular acceleration of the three-phase rotating electrical machine is greater than or equal to a threshold value in the second mode. It is characterized by switching to.

  In the above configuration, prior to each on operation of the pair of switching elements on the high voltage side and the low voltage side connected to each of the three winding terminals of the three-phase rotating electrical machine, the timing at which the predetermined phase is reached is defined as the rotation angle. A detection process is performed for use as information. For this reason, since the detection opportunity of the timing which becomes a predetermined phase is 6 times in one cycle of the electrical angle, the detection frequency of the predetermined phase can be sufficiently secured.

  However, since the overlap amount in the second mode is longer than the overlap amount in the first mode, there is a possibility that the predetermined phase cannot be detected when the absolute value of the rotational angular acceleration is large. That is, for example, if the subsequent rotational speed is higher than the rotational speed between the timings of the two most recent predetermined phases, the induced voltage is calculated from the voltage of the winding terminal connected to the switching element to be turned on. There is a possibility that the predetermined phase appears before detection becomes possible, and as a result, the predetermined phase cannot be detected. And when a predetermined phase cannot be detected, controllability falls. For this reason, it is considered that the second mode is less resistant to rotational fluctuations than in the first mode. In this regard, in the above configuration, when the absolute value of the rotational angular acceleration is equal to or greater than the threshold, switching from the second mode to the first mode suppresses a decrease in resistance to rotational fluctuations and ensures an overlap amount. It is possible to achieve a suitable balance.

  2. In the control device for a three-phase rotating electrical machine according to the above 1, in the second mode, the ON operation timing of the target switching element predicted based on the detection results of the past plural times of the timing at which the predetermined phase is reached A setting processing unit configured to set an end point of a monitoring period that is a detection period of the induced voltage; and a monitor processing unit that monitors the induced voltage in the monitoring period, wherein the switching processing unit sets the predetermined phase in the monitoring period. If not detected, the second mode is switched to the first mode, assuming that the absolute value of the electrical angular acceleration is greater than or equal to a threshold value.

  When the end point of the monitoring period is set as described above, the monitoring period is until the predicted on-operation timing. Therefore, when the absolute value of the rotational angular acceleration is small, the timing for the predetermined phase is included in the monitoring period. It is thought that. Therefore, when the predetermined phase cannot be detected during the monitoring period, it is determined that the absolute value of the rotational angular acceleration is equal to or greater than the threshold value.

  3. 2. The control device for a three-phase rotating electrical machine according to claim 1, wherein a speed corresponding to a rotational speed of the three-phase rotating electrical machine and a correlation value thereof is calculated based on the detected time difference between the predetermined phases. A calculation processing unit, wherein the switching processing unit determines that the absolute value of the electrical angular acceleration is equal to or greater than a threshold when the change rate of the speed equivalent value calculated by the speed calculation processing unit is equal to or greater than a predetermined value. The mode is switched from the second mode to the first mode.

  In the case of the above configuration, since the predetermined phase occurs every “60 °”, the speed equivalent value can be calculated based on the time difference between the predetermined phases. Since the change speed of the speed equivalent value corresponds to the rotational angular acceleration, it is determined based on this whether or not the absolute value of the rotational angular acceleration is equal to or greater than a threshold value. In particular, by using the change speed of the speed equivalent value, it is possible to determine at an early stage whether or not it becomes impossible to detect the predetermined phase of the induced voltage through the monitoring of the voltage at the winding terminal in the second mode. Become. In this case, the probability that the predetermined phase cannot be detected can be reduced.

  4). 2. The control device for a three-phase rotating electrical machine according to claim 1, further comprising a current detection processing unit that detects a current flowing through the three-phase rotating electrical machine, wherein the switching processing unit is a detection value of a current detected by the current detection processing unit. When the amount of variation of the electric field acceleration is equal to or greater than a threshold value, the second mode is switched to the first mode, assuming that the absolute value of the electrical angular acceleration is equal to or greater than the threshold value.

  The current flowing through the three-phase rotating electric machine has a correlation with the torque of the three-phase rotating electric machine. For this reason, when the fluctuation amount of the detected current value is large, the fluctuation amount of the torque is considered to be large, and as a result, the rotational angular acceleration may be increased. In the above configuration, in view of this point, when the fluctuation amount of the detected current value is equal to or greater than the threshold value, it is determined that the absolute value of the rotational angular acceleration is equal to or greater than the threshold value.

  5. In the control device for a three-phase rotating electrical machine according to 1 above, the switching processing unit assumes that the absolute value of the electrical angular acceleration is greater than or equal to the threshold when the amount of change in the detected value of the input voltage of the inverter is greater than or equal to the threshold. The second mode is switched to the first mode.

  When the input voltage is high, the voltage applied by the inverter to the winding terminals of the three-phase rotating electrical machine is higher than when the input voltage is low. For this reason, when the input voltage is high, the rotational speed of the three-phase rotating electrical machine is higher than when the input voltage is low. For this reason, when the fluctuation amount of the detected value of the input voltage is large, the fluctuation amount of the rotation speed of the three-phase rotating electrical machine becomes large. In view of this point, in the above configuration, it is determined whether or not the absolute value of the electrical angular acceleration is greater than or equal to the threshold value based on the detected value of the input voltage. In particular, since fluctuations in the input voltage cause changes in the rotational angular acceleration, using the detected value of the input voltage allows rapid detection in situations where the predetermined phase may not be detected depending on the second mode. It is also possible to switch to the first mode.

  6). In the control device for a three-phase rotating electrical machine according to the above-described item 1, the apparatus includes a current detection processing unit that detects a current flowing through the three-phase rotating electrical machine, and a current feedback processing unit that controls the detected current to a current command value. When the absolute value of the difference between the detected current value detected by the current detection processing unit and the current command value is greater than or equal to a threshold value, the switching processing unit assumes that the absolute value of the electrical angular acceleration is greater than or equal to the threshold value. The second mode is switched to the first mode.

  If the absolute value of the difference between the detected current value and the current command value is greater than or equal to the threshold value, the current feedback processing unit is controlled to reduce this difference, so that the amount of current fluctuation is considered to increase. When the current fluctuation amount increases, the torque fluctuation amount of the three-phase rotating electrical machine increases, and therefore the absolute value of the rotational angular acceleration is likely to increase. In the above configuration, in view of this point, when the absolute value of the difference between the detected current value and the current command value is equal to or greater than the threshold value, it is determined that the absolute value of the rotational angular acceleration is equal to or greater than the threshold value.

  7). 2. The control device for a three-phase rotating electrical machine according to the above item 1, further comprising a current detection processing unit that detects a current flowing through the three-phase rotating electrical machine, wherein the switching processing unit is an absolute value of the current detected by the current detection processing unit. When is greater than or equal to a threshold, the absolute value of the electrical angular acceleration is assumed to be greater than or equal to the threshold, and the second mode is switched to the first mode.

  From the assumed range of torque applied to the rotating shaft of the three-phase rotating electrical machine, it is considered that there is an assumed range for the absolute value of the current flowing through the three-phase rotating electrical machine. For this reason, when the absolute value of the current flowing through the three-phase rotating electrical machine is excessively large, the rotational state of the three-phase rotating electrical machine is greatly deviated from the steady rotational state, and the rotational angular acceleration is increased. In the above configuration, in view of this point, when the absolute value of the current is equal to or greater than the threshold value, it is determined that the absolute value of the electrical angular acceleration is equal to or greater than the threshold value.

  8). 2. The control device for a three-phase rotating electrical machine according to claim 1, wherein a speed corresponding to a rotational speed of the three-phase rotating electrical machine and a correlation value thereof is calculated based on the detected time difference between the predetermined phases. A calculation processing unit, and a speed feedback processing unit that feedback-controls the calculated speed equivalent value to a speed command value, wherein the switching processing unit is an absolute value of a difference between the speed equivalent value and the speed command value When is greater than or equal to a threshold, the absolute value of the electrical angular acceleration is assumed to be greater than or equal to the threshold, and the second mode is switched to the first mode.

  When the absolute value of the difference between the speed equivalent value and the speed command value is greater than or equal to the threshold value, the speed feedback processing unit is controlled to reduce this difference, so the absolute value of the rotational angular acceleration is considered to increase. . In the above configuration, in view of this point, when the absolute value of the difference between the speed equivalent value and the speed command value is equal to or greater than the threshold value, it is determined that the absolute value of the rotational angular acceleration is equal to or greater than the threshold value.

  9. 2. The control device for a three-phase rotating electrical machine according to claim 1, wherein a speed corresponding to a rotational speed of the three-phase rotating electrical machine and a correlation value thereof is calculated based on the detected time difference between the predetermined phases. A switching processing unit is provided, and the switching processing unit switches from the second mode to the first mode when the speed equivalent value is equal to or lower than a specified speed.

  When the rotational speed of the three-phase rotating electrical machine is excessively low, the rotational state of the three-phase rotating electrical machine tends to be unstable. In the above configuration, in view of this point, when the speed equivalent value is equal to or less than the specified speed, switching to the first mode increases the possibility that a predetermined phase can be detected, thereby suppressing the rotation state from becoming unstable. To do.

  10. 10. The control device for a three-phase rotating electrical machine according to any one of 1 to 9, wherein the start-up processing unit starts the three-phase rotating electrical machine by operating the inverter without being based on detection of the predetermined phase. The switching processing unit selects the first mode over a predetermined period after the processing of the activation processing unit is completed.

  There is a tendency that the rotation speed is not stable during a period immediately after the completion of the processing by the activation processing unit. In the above configuration, in view of this point, by selecting the first mode over a predetermined period after completion, the possibility that a predetermined phase can be detected in a situation where the rotational speed is not stable is increased, and thus the rotational state is unstable. To suppress.

1 is a system configuration diagram according to a first embodiment. FIG. (A) And (b) is a time chart which shows the 1st mode and 2nd mode concerning the embodiment. (A) And (b) is a time chart which shows transition of the operation amount by the current feedback control concerning the embodiment. The time chart which shows the relationship between overlap amount and torque ripple. The figure which shows the relationship between overlap amount and torque ripple. The flowchart which shows the procedure of the drive process of the motor concerning the said embodiment. The flowchart which shows the procedure of the calculation process of the rotational speed concerning the embodiment. The flowchart which shows the procedure of the mode switching process concerning the embodiment. The system block diagram concerning 2nd Embodiment. (A) And (b) is a time chart which shows transition of the operation amount by the speed feedback control concerning the embodiment. The flowchart which shows the procedure of the mode switching process concerning the embodiment.

<First Embodiment>
Hereinafter, a first embodiment of a control device for a three-phase rotating electrical machine will be described with reference to the drawings.

  FIG. 1 shows a system configuration according to the present embodiment. The motor 10 shown in FIG. 1 is a surface magnet synchronous motor (SPMSM). Further, the motor 10 is obtained by Y-connecting three stator coils. The motor 10 is built in an oil pump 12 that discharges oil to a CVT (continuously variable transmission) 14 provided in the drive system of the vehicle. A battery (DC voltage source) 16 is connected to the motor 10 via an inverter INV. The inverter INV is a circuit that opens and closes between each of the high voltage side voltage source terminal and the low voltage side voltage source terminal of the battery 16 and each of the three winding terminals of the motor 10. The winding terminal is a terminal of the stator coil and is a portion that connects a member outside the motor 10 and the stator coil.

  In FIG. 1, among the symbols of the switching elements (MOS field effect transistors) constituting the inverter INV, those connected to each of the three winding terminals of the motor 10 are “u, v, w”. In addition, “p” is given to the upper arm and “n” is given to the lower arm. In the following, “u, v, w” are collectively expressed as “¥”, and “p, n” are collectively expressed as “#”. That is, the inverter INV includes a switching element S ¥ p that opens and closes between the high voltage side voltage source terminal of the battery 16 and the winding terminal of the motor 10, and the low voltage side voltage source terminal of the battery 16 and the motor 10. A series connection body with a switching element S ¥ n that opens and closes between the winding terminals is provided. A diode D ¥ # is connected in antiparallel to each of the switching elements S ¥ #.

  A voltage sensor 18 is provided between a pair of input terminals of the inverter INV connected to the voltage source terminal on the high voltage side and the voltage source terminal on the low voltage side of the battery 16. An input voltage Vdc is detected. Further, a shunt resistor 20 is provided between the input terminal on the low voltage side of the inverter INV and the voltage source terminal on the low voltage side of the battery 16 (DC bus on the low voltage side). The voltage drop across the shunt resistor 20 is detected by the voltage sensor 22. Voltage sensor 22 detects current I flowing through the DC bus by detecting a voltage drop.

  The control device 30 includes a phase detection circuit 32 and a control unit 34. Here, the phase detection circuit 32 detects a predetermined phase of the induced voltage when the induced voltage appears in the terminal voltage V ¥ of the motor 10. In the present embodiment, the predetermined phase is a phase in which the sign of the induced voltage appearing at each winding terminal is inverted. In other words, the phase is such that an induced voltage zero-cross occurs. A known technique may be applied as the configuration of the phase detection circuit 32. Specifically, for example, detecting the inversion timing of the neutral point voltage and each terminal voltage V ¥ as the zero cross timing, or “1/2” of the input voltage of the inverter INV and each terminal voltage V ¥ It is possible to employ one that detects the small and large inversion timing as zero cross timing.

  The control unit 34 includes a central processing unit (CPU) and a storage device, and operates the inverter INV to control the control amount of the motor 10 by executing a program stored in the storage device by the CPU. That is, the inverter INV is operated by outputting the operation signal g ¥ # to the switching element S ¥ # of the inverter INV. When outputting the operation signal g ¥ #, the control unit 34 may be provided with a drive circuit, and a signal from the CPU may be output to the inverter INV via the drive circuit.

  FIG. 2 shows a switching operation pattern of the inverter INV according to the present embodiment. In FIG. 2, the angle region in which the switching element S ¥ # is written indicates a region where the on operation of the switching element S ¥ # is permitted (on operation permission region). Here, as for the switching element S ¥ p of the upper arm, the switching element S ¥ # is always in the ON state during the ON operation permission region. On the other hand, for the switching element S ¥ n of the lower arm, the switching element S ¥ n is turned on / off during the on-operation permission period. Here, the duty ratio of the ON operation time with respect to one cycle of the ON / OFF operation of the switching element S ¥ # is a current command input from the outside to the control device 30 as the current I as the control amount of the motor 10. This is the operation amount for feedback control to the value I *.

  FIG. 3 exemplifies a duty ratio when performing current feedback control. FIG. 3A and FIG. 3B illustrate the time ratios when the current command value I * is large and small when the input voltage Vdc is the same. As shown in the figure, since the current I can be increased by increasing the duty ratio, the duty ratio tends to increase when the current command value I * is large.

  As shown in FIG. 2, the control unit 34 drives the motor 10 by providing a period for current to flow through two of the stator coils connected to each of the three winding terminals of the motor 10. Here, the two stator coils to be energized have an angular region in which the combined vector of magnetic flux generated by energizing them has an equal width on the advance side and the retard side with respect to a direction orthogonal to the magnetic pole. It shall be In the present embodiment, this angle region is set to an angle region of “120 °” in the first mode shown in FIG. 2A, and “130 to 140 °” in the second mode shown in FIG. A predetermined angle region is set.

  The on operation of the switching element S ¥ # in the first mode and the second mode is executed as follows. As shown in FIG. 2, an induced voltage e ¥ appears at the winding terminal where both the upper arm switching element S ¥ p and the lower arm switching element S ¥ n are off. For this reason, the control unit 34 sets a monitoring period, which is a detection period of the induced voltage, based on a period in which both of the winding terminals of the motor 10 are off, and the phase detection circuit 32 detects the monitoring period. The switching element S ¥ # is turned on using the zero cross timing of the induced voltage e ¥ as the rotation angle information. In FIG. 2, the zero cross timing is indicated by a broken line.

  Specifically, first, based on a time difference between a pair of past zero cross timings, a predetermined angular width before and after the next zero cross timing when the rotational speed of the motor 10 is constant is predicted, and this predicted period Is the monitoring period. Here, the predetermined angular width is “30 °” in the first mode. Next, by detecting the zero cross timing in the monitoring period, the time from the current zero cross timing to the rotation of the motor 10 by the predetermined angle width is calculated based on the time difference between the zero cross timing and the previous zero cross timing. When the time elapses, the switching element S ¥ # is turned on. Incidentally, according to such setting, the end point of the monitoring period is the ON operation timing of the switching element S ¥ # predicted based on the time difference between the pair of past zero cross timings. For this reason, in this embodiment, in the first mode, when the zero cross timing cannot be detected in the monitoring period, the switching element S ¥ # is turned on at the end of the monitoring period.

  As shown in FIG. 2B, in the second mode, any one of the switching element S ¥ p of the upper arm and the switching element S ¥ n of the lower arm at all three winding terminals of the motor 10. The overlap amount, which is the length of the energization angle region where is turned on, is set to be larger than zero. The second mode is provided with the aim of reducing torque ripple of the motor 10 and suppressing rattling noise and vibration of the oil pump 12. FIG. 4 shows the relationship between the overlap amount and torque ripple.

  The curve fa shown in FIG. 4 shows the torque waveform in the first mode in which the overlap amount is zero, and the curves fb and fc are the torque waveforms when the overlap amount is “5 °” and “10 °”, respectively. Indicates. FIG. 5 quantifies the torque ripple as a ripple amount and obtains the reduction ratio of the torque ripple with respect to when the overlap amount is zero. In FIG. 5, the torque ripple is quantified as the ratio of the maximum value with respect to the absolute value of the difference between the average value and the instantaneous value to the average value of the torque.

  As shown in FIGS. 4 and 5, torque ripple can be reduced by increasing the overlap amount. Therefore, in the second mode, an overlap amount that can effectively reduce the torque ripple is set while securing the monitoring period.

  However, as can be seen from the comparison between FIG. 2A and FIG. 2B, the increase in the overlap amount shortens the monitoring period. And when a monitoring period is shortened, the tolerance with respect to a rotation fluctuation falls. That is, as described above, in the present embodiment, the monitoring period is set to a period before and after the predicted zero-cross timing based on the past zero-cross timing. It becomes easy to get out of the monitoring period.

  Therefore, in the present embodiment, when the absolute value of the rotational angular acceleration of the motor 10 becomes large, the second mode is switched to the first mode because the zero cross timing may not be detected during the monitoring period. This will be described in detail below.

FIG. 6 shows a procedure for driving the motor 10 according to the present embodiment. This process is repeatedly executed in the control unit 34 at a predetermined cycle, for example.
In the series of processes shown in FIG. 6, the control unit 34 first determines whether or not an operation command for the motor 10 has been issued (S10). When determining that the operation command has been issued (S10: YES), the control unit 34 executes a startup process of the motor 10 (S12). Here, when the rotational speed of the motor 10 is low, the absolute value of the induced voltage e ¥ is small. Therefore, instead of performing sensorless processing based on the induced voltage e ¥, the switching pattern shown in FIG. The switching element S ¥ # is operated at a predetermined frequency. Subsequently, the control unit 34 determines whether or not the zero cross timing of the induced voltage e ¥ can be detected (S14). This process is for determining whether the sensorless process based on the induced voltage e ¥ can be executed. Here, it may be determined that it can be executed when the absolute value of the induced voltage e ¥ is greater than or equal to a predetermined value during the monitoring period and sign inversion is detected.

  When the zero cross timing can be detected (S14: YES), the control unit 34 performs sensorless processing in the first mode based on the zero cross timing (S16). Here, the reason why the first mode is selected is that the fluctuation of the rotation speed is considered to be large immediately after the start-up process is completed. That is, before shifting to the process of step S16, the torque generated by the motor 10 is sufficient to perform the switching operation with the switching pattern shown in FIG. 2A without grasping the rotation angle of the motor 10. Instead, the rotational speed is low compared to the case where the process of step S16 is performed constantly. For this reason, it is thought that the rotational speed of the motor 10 increases by shifting to the process of step S16.

  Thereafter, the control unit 34 determines whether or not the rotation speed is stable (S18). If the controller 34 determines that the rotation speed is stable (S18: YES), the controller 34 performs sensorless processing in the second mode based on the zero cross timing (S20).

Note that if the control unit 34 makes a negative determination in step S10 or if the process of step S20 is completed, the process shown in FIG. 6 is temporarily terminated.
As described above, the control unit 34 performs a process of calculating a time difference between a pair of zero cross timings at the time of sensorless processing based on the zero cross timings. In particular, in the present embodiment, processing for calculating the rotational speed (electrical angular speed) ω of the motor 10 is performed.

  FIG. 7 shows the procedure for calculating the rotational speed ω. This process is repeatedly executed by the control unit 34, for example, at a predetermined cycle during the execution of the sensorless process based on the zero cross timing.

  In this series of processing, the control unit 34 first determines whether or not zero cross timing is detected (S30). When detecting the zero cross timing (S30: YES), the control unit 34 calculates a time difference ΔT between the current zero cross timing and the previous zero cross timing (S32). Then, the control unit 34 calculates the rotation speed ω based on the time difference ΔT (S34).

Note that when the process of step S34 is completed or when a negative determination is made in step S30, the control unit 34 temporarily ends the series of processes shown in FIG.
FIG. 8 shows a procedure for switching processing between the first mode and the second mode according to the present embodiment. This process is repeatedly executed by the control unit 34, for example, at a predetermined cycle.

  In the series of processes shown in FIG. 8, the control unit 34 first determines whether or not a sensorless process based on the zero cross timing is being executed (S40). Then, when making a positive determination in step S40, the control unit 34 determines whether or not the logical sum of the following conditions is true (S42). This process is for determining whether or not to shift to the first mode.

  (A) A condition that the zero cross timing cannot be detected during the monitoring period. As described above, the monitoring period is set to a predetermined angular width sandwiching the predicted zero cross timing based on the time difference between the past zero cross timings. Here, when the absolute value of the rotational angular acceleration is small, it is considered that the zero cross timing is included in the monitoring period. Therefore, when the zero cross timing cannot be detected during the monitoring period, it is determined that the absolute value of the rotational angular acceleration is equal to or greater than the threshold value.

  (A) A condition that the rotational speed ω is equal to or less than the specified speed ωth. This condition is provided in view of the fact that the rotational state of the motor 10 tends to be unstable when the rotational speed of the motor 10 is excessively low. In this case, by shifting to the first mode, the possibility that the zero-cross timing can be detected is increased, and as a result, the rotational state is prevented from becoming unstable.

(C) A condition that the change speed Δω of the rotational speed ω (the detected value of the rotational angular acceleration) is equal to or greater than the threshold value Δωth.
(D) A condition that the fluctuation amount ΔI of the current I is equal to or greater than the threshold value ΔIth1. The current I flowing through the motor 10 has a correlation with the torque of the motor 10. For this reason, when the fluctuation amount ΔI of the current I is large, it is considered that the fluctuation amount of the torque is increased, and as a result, the rotational angular acceleration may be increased. Here, the fluctuation amount ΔI is an absolute value of a difference between the minimum value and the maximum value of the current I in a predetermined period.

  (E) A condition that the fluctuation amount ΔVdc of the input voltage Vdc is equal to or greater than the threshold value ΔVth. When the input voltage Vdc is high, the voltage applied to the winding terminal of the motor 10 by the inverter INV is larger than when the input voltage Vdc is low. For this reason, when the input voltage Vdc is high, the rotational speed of the motor 10 increases compared to when the input voltage Vdc is low. Therefore, when the fluctuation amount ΔVdc of the input voltage Vdc is large, the fluctuation amount of the rotation speed becomes large. In view of this point, when the input voltage Vdc is equal to or greater than the threshold value ΔVth, it is determined that the absolute value of the rotational angular acceleration is equal to or greater than the threshold value.

  (F) A condition that the absolute value of the difference between the current I and the current command value I * is equal to or greater than the threshold value ΔIth2. When the absolute value of the difference between the current I and the current command value I * is equal to or greater than the threshold value ΔIth2, the current feedback control is performed so as to reduce this difference. When the current fluctuation amount increases, the torque fluctuation amount of the motor 10 increases, so that the absolute value of the rotational angular acceleration is likely to increase. In view of this point, when the absolute value of the difference between the current I and the current command value I * is equal to or greater than the threshold value ΔIth2, it is determined that the absolute value of the rotational angular acceleration is equal to or greater than the threshold value.

  (G) A condition that the current I is greater than or equal to the threshold value Ith. From the assumed range of torque applied to the rotating shaft of the motor 10, it is considered that there is an assumed range for the current I flowing through the motor 10. For this reason, when the current I flowing through the motor 10 is excessively large, it is considered that the rotational state of the motor 10 deviates greatly from the steady rotational state and the rotational angular acceleration increases. In view of this point, when the current I is equal to or greater than the threshold value Ith, it is determined that the absolute value of the electrical angular acceleration is equal to or greater than the threshold value.

  When it is determined that the logical sum is true (S42: YES), the control unit 34 performs sensorless processing in the first mode (S44). Here, when the sensorless process in the second mode is currently being executed, the process shifts to the first mode. On the other hand, if the sensorless process in the first mode is currently being executed, the sensorless process in the first mode is continued as it is. On the other hand, when the controller 34 determines that the logical sum is false (S42: NO), the controller 34 performs sensorless processing in the second mode (S46). Here, when the sensorless process in the first mode is being executed at this time, the mode is shifted to the second mode. On the other hand, if the sensorless process in the second mode is currently being executed, the sensorless process in the second mode is continued as it is.

In addition, the control part 34 once complete | finishes this series of processes, when it makes a negative determination in step S40, or when the process of step S44, S46 is completed.
Next, the operation of this embodiment will be described.

  The control unit 34 activates the motor 10 according to the procedure shown in FIG. 6 according to the operation command of the motor 10, and executes sensorless processing in the second mode. Thereafter, the control unit 34 determines whether or not the logical sum is true by the process of step S42 in FIG. Then, when the logical sum is true, the control unit 34 shifts to the sensorless process in the first mode. As a result, the second mode is shifted to the first mode in a situation where it is difficult to detect the zero-cross timing during the monitoring period, such as when the absolute value of the rotational angular acceleration of the motor 10 is greater than or equal to the threshold value. In the first mode, since the monitoring period is longer than that in the second mode, the possibility that the zero cross timing can be detected is improved as compared with the case where the second mode is continued.

According to the present embodiment described above, the following effects can be obtained.
(1) In the second mode, when the absolute value of the rotational angular acceleration is equal to or greater than the threshold value, the mode is shifted to the first mode. This improves the possibility that the zero-cross timing can be detected as compared with the case where the second mode is continued. Therefore, suitable coexistence of suppressing a decrease in resistance to rotational fluctuation and ensuring an overlap amount is achieved. Can be achieved.

  (2) In the starting process of the motor 10, the switching element S ¥ # is operated by the same switching pattern as in the first mode. As a result, the monitoring period can be extended as compared with the case where the switching element S ¥ # is operated by the same switching pattern as in the second mode, and therefore, the sensorless processing based on the zero cross timing can be promptly shifted. .

<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 control unit 34 feedback-controls the rotational speed ω to the command value (speed command value ω *) instead of feedback-controlling the current I to the current command value I *.
FIG. 9 shows a system configuration according to the present embodiment. In FIG. 9, components corresponding to those shown in FIG.

  As shown in FIG. 9, in this embodiment, a speed command value ω * is input to the control device 30 from the outside. Then, the control unit 34 manipulates the time ratio of the switching element S ¥ n of the lower arm in order to feedback control the rotational speed ω as the control amount of the motor 10 to the speed command value ω *. As a result, when the input voltage Vdc has the same magnitude, as shown in FIG. 10B, the speed command value ω * is greater when the speed command value ω * is larger as shown in FIG. Since torque is required as compared with the case where it is small, the duty ratio tends to be set to a large value.

  FIG. 11 shows a procedure for switching processing between the first mode and the second mode according to the present embodiment. This process is repeatedly executed by the control unit 34, for example, at a predetermined cycle. In FIG. 11, processes corresponding to the processes shown in FIG. 8 are given the same step numbers for convenience.

  As shown in FIG. 11, in place of step S42, the control unit 34 performs a logical sum of the above conditions (a) to (e) and (g) and the following condition (c) in step S42a. Determine whether it is true.

  (H) A condition that the absolute value of the difference between the rotational speed ω and the speed command value ω * is equal to or greater than a threshold value Δωth2. When the absolute value of the difference between the rotational speed ω and the speed command value ω * is equal to or greater than the threshold value, feedback control is performed so as to reduce the difference, and thus the absolute value of the rotational angular acceleration is considered to increase. In view of this point, when the absolute value of the difference between the rotational speed ω and the speed command value ω * is equal to or greater than the threshold, it is determined that the absolute value of the rotational angular acceleration is equal to or greater than the threshold.

<Other embodiments>
In addition, you may change at least 1 of each matter of the said embodiment as follows. In the following, typical correspondence between each item described in “Means for Solving the Problem” and the above-described embodiment will be described with reference numerals and figure numbers. There is no intention to limit each of the above items to those corresponding to or figure numbers. Incidentally, the current feedback processing unit described in “Means for Solving the Problems” is realized by the control device 30 of FIG. 1 (see also FIG. 3). Further, the speed feedback processing unit is realized by the control device 30 of FIG. 9 (see also FIG. 10).

・ About the first mode
The ON operation permission region of the switching element S ¥ # of the upper arm or the lower arm is not limited to “120 °”. For example, it may include a period in which only one switching element connected to one of the three winding terminals of the motor 10 is in the ON operation permission region, such as “118 °”. The overlap amount is not limited to zero. The point is that the overlap amount is smaller than that in the second mode.

・ About the second mode
The ON operation permission region of the switching element S ¥ # of the upper arm or the lower arm is not limited to “130 to 140 °”. For example, it may be larger than “140 °”. Further, if the overlap amount in the second mode is longer than the overlap amount in the first mode, it may be less than “130 °”.

・ "Switching between 1st mode and 2nd mode"
For example, when an affirmative determination is made in step S42 of FIG. 8, the mode may be shifted from the second mode to the first mode, and the negative determination may be continued for a predetermined time to shift to the first mode. Also, for example, in step S42, the hysteresis is reduced by making the values used for the determinations (a) to (g) related to the transition condition from the first mode to the second mode different from those at the transition to the first mode. It may be provided. Specifically, for example, the specified speed ωth in (b) may be set to a value larger than the value at the time of shifting to the first mode.

・ "Rotation angle sensorless processing part"
The zero cross timing is detected by monitoring the voltage V ¥ of the winding terminal connected to the switching element S ¥ # to be turned on, and based on this, the switching element S ¥ # to be turned on is turned on. It is not restricted to what is operated. For example, on the basis of the zero cross timing of the induced voltage eu detected prior to turning on the switching element Sun, the switching element Swp to be turned on next to the switching element Sun may be turned on.

  An angle region having a predetermined angular width that is equal to before and after the timing at which the direction of the magnetic field generated by the current flowing in the stator coil is orthogonal to the direction of the magnetic pole is not limited to the ON operation permission region. For example, in a high rotation area, a process of advancing a predetermined amount with respect to this angle area may be performed. However, in this case, the first mode is desirable in order to increase the possibility of detecting the zero cross.

The feedback control amount is not limited to the current I or the rotational speed ω. For example, both of them may be used.
The operation amount for controlling the current I and the rotational speed ω, which are control amounts, is not limited to the time ratio of the switching element S ¥ n of the lower arm. For example, the duty ratio of the switching element S ¥ p of the upper arm may be used. Of course, the duty ratio is not limited to variable.

・ "About switching processing unit (S42, S42a)"
In the processing in step S42 in FIG. 8, for example, it is not limited to determining whether the logical sum of all the conditions (A) to (K) is true, and whether or not at least one condition is satisfied. It may be a thing to judge. That is, for example, a process for determining whether the logical sum of the above conditions (a) and (c) is true or a process for determining whether the condition (c) is satisfied, for example. Also good.

  In the process in step S42a in FIG. 11, for example, the process is not limited to determining whether the logical sum of all the conditions (A) to (E), (K), and (K) is true, It may be determined whether one condition is satisfied. That is, for example, a process for determining whether the logical sum of the above conditions (a) and (c) is true or a process for determining whether the condition (c) is satisfied, for example. Also good.

  For example, if the rotation angle sensorless processing unit uses both the current I and the rotation speed ω as feedback control amounts, it is determined whether the logical sum of the above conditions (f) and (c) is true. May be.

・ "Speed calculation processing unit (Fig. 7)"
In FIG. 7, the rotational speed ω is calculated as the speed equivalent value, but the present invention is not limited to this. For example, the time difference ΔT itself may be calculated as a speed equivalent value.

・ About the current detection processing unit
In the above embodiment, the process of sampling the detection value of the voltage sensor 22 that detects the voltage drop of the shunt resistor 20 is the current detection process by the control unit 34 (process by the current detection processing unit), but is not limited thereto. For example, the current detection process may be a process that performs a process of sampling each of the potentials at both ends of the shunt resistor 20 and a process of calculating the current I based on the values of the paired sampled potentials.

  Further, the shunt resistor is not limited to the one provided on the DC bus on the low voltage side, and may be provided on the DC bus on the high voltage side, for example. For example, each leg may be provided with a shunt resistor. This may be provided, for example, between the voltage source terminal on the low voltage side of the battery 16 and each of the switching elements Sun, Svn, Swn, or provided on the high voltage side of the battery 16, for example. It may be.

・ About “Startup Processing Unit (S12)”
In the above-described embodiment, since “zero cross” can be detected, “completion of processing by the activation processing unit” is described, but the present invention is not limited thereto. For example, it may be at the elapse of time having a predetermined length.

  The ratio of the ON operation permission area in one cycle of the switching pattern is not limited to the same as that in the first mode. For example, the ratio may be lowered. Thereby, the zero cross can be detected earlier.

Moreover, it is not limited to fixing the time interval of one cycle of the switching pattern, but may be gradually shortened, for example.
・ About "predetermined period"
In the above embodiment, the predetermined period for shifting to the second mode after the completion of the processing by the activation processing unit is the period until the rotation speed ω is stabilized, but is not limited thereto. For example, it may be a time having a predetermined length.

・ "About 3-phase rotating electrical machines"
The transmission that is the oil discharge destination of the oil pump 12 built in the motor 10 is not limited to the CVT 14 and may be, for example, a stepped transmission. Further, the oil discharge destination of the oil pump 12 is not limited to the transmission, and may be, for example, an internal combustion engine.

  The three-phase rotating electrical machine is not limited to SPMSM, and may be, for example, an embedded magnet synchronous motor (IPMSM). Further, the three-phase rotating electrical machine is not limited to a three-phase motor, and may be, for example, a three-phase generator. Further, the three stator coils are not limited to Y-connected, but may be Δ-connected, for example.

・ About the computer that executes the process
In the above embodiment, the control unit 34 includes a CPU and a storage device for a program executed by the CPU, and the processes of FIGS. 6 to 8 and FIG. 11 are realized by the execution of the program by the CPU. . For example, at least a part of the processing in FIGS. 6 to 8 and 11 may be hardware processing such as ASIC (Application Specific Integrated Circuit). In other words, the computer that executes at least a part of the processes of FIGS. 6 to 8 and 11 may not be hardware that executes software processing, but may be dedicated hardware.

·"others"
The DC voltage source connected to each winding terminal of the motor 10 via the inverter INV is not limited to the battery 16 and may be, for example, a capacitor.

  DESCRIPTION OF SYMBOLS 10 ... Motor, 12 ... Oil pump, 14 ... CVT, 16 ... Battery, 18 ... Voltage sensor, 20 ... Shunt resistance, 22 ... Voltage sensor, 30 ... Control apparatus, 32 ... Phase detection circuit, 34 ... Control part.

Claims (10)

In a control device for a three-phase rotating electrical machine that controls the control amount of the three-phase rotating electrical machine by operating an inverter,
The inverter includes a plurality of pairs of switching elements that open and close between the voltage source terminals on the high voltage side and the low voltage side of the DC voltage source and the winding terminals of the three-phase rotating electrical machine,
Prior to turning on each of the pair of switching elements on the high voltage side and the low voltage side connected to each of the three winding terminals of the three-phase rotating electrical machine, the switching element to be turned on The three-phase rotation for executing processing for obtaining rotation angle information of the three-phase rotating electric machine by detecting a timing at which the phase of the induced voltage of the three-phase rotating electric machine appearing at the connected winding terminal becomes a predetermined phase An electrical rotation angle sensorless processing unit;
A first mode in which an overlap amount, which is a length of an energization angle region in which any one of the pair of switching elements is turned on in all of the three winding terminals, is equal to or greater than zero; A switching processing unit that switches between a second mode longer than the amount in the first mode,
The switching processing unit switches from the second mode to the first mode when the absolute value of the electrical angular acceleration of the three-phase rotating electrical machine is equal to or greater than a threshold value in the second mode. Electric control device. In the second mode, the ON operation timing of the target switching element that is predicted based on the detection results of the past multiple times of the predetermined phase timing is set as the end point of the monitoring period that is the detection period of the induced voltage A setting processing unit for monitoring, and a monitoring processing unit for monitoring the induced voltage in the monitoring period,
The switch processing unit switches from the second mode to the first mode, assuming that the absolute value of the electrical angular acceleration is equal to or greater than a threshold value when the predetermined phase cannot be detected during the monitoring period. A control device for a three-phase rotating electric machine. A speed calculation processing unit that calculates a speed equivalent value that is one of a rotational speed of the three-phase rotating electrical machine and a correlation value thereof based on the detected time difference between the predetermined phases;
When the change speed of the speed equivalent value calculated by the speed calculation processing unit is greater than or equal to a predetermined value, the switching processing unit determines that the absolute value of the electrical angular acceleration is greater than or equal to a threshold value and the first mode from the second mode. The control device for a three-phase rotating electric machine according to claim 1, wherein the controller is switched to a mode. A current detection processing unit for detecting a current flowing through the three-phase rotating electrical machine;
The switching processing unit determines that the absolute value of the electrical angular acceleration is greater than or equal to the threshold when the fluctuation amount of the detected current value detected by the current detection processing unit is greater than or equal to the threshold. The control device for a three-phase rotating electrical machine according to claim 1, wherein the control device switches to one mode.   The switching processing unit switches from the second mode to the first mode on the assumption that the absolute value of the electrical angular acceleration is equal to or greater than a threshold when the amount of change in the detected value of the input voltage of the inverter is equal to or greater than the threshold. Item 3. A control device for a three-phase rotating electrical machine according to Item 1. A current detection processing unit for detecting a current flowing through the three-phase rotating electrical machine;
A current feedback processing unit for controlling the detected current to a current command value;
When the absolute value of the difference between the detected current value detected by the current detection processing unit and the current command value is greater than or equal to a threshold value, the switching processing unit assumes that the absolute value of the electrical angular acceleration is greater than or equal to the threshold value. The control device for a three-phase rotating electrical machine according to claim 1, wherein the control is switched from the second mode to the first mode. A current detection processing unit for detecting a current flowing through the three-phase rotating electrical machine;
When the absolute value of the current detected by the current detection processing unit is equal to or greater than a threshold value, the switching processing unit determines that the absolute value of the electrical angular acceleration is equal to or greater than the threshold value, and changes from the second mode to the first mode. The control device for a three-phase rotating electrical machine according to claim 1 to be switched. Based on the detected time difference between the predetermined phases, a speed calculation processing unit that calculates a speed equivalent value that is one of the rotation speed of the three-phase rotating electrical machine and its correlation value;
A speed feedback processing unit that feedback-controls the calculated speed equivalent value to a speed command value,
When the absolute value of the difference between the speed equivalent value and the speed command value is equal to or greater than a threshold value, the switching processing unit determines that the absolute value of the electrical angular acceleration is equal to or greater than the threshold value, from the second mode to the first The control device for a three-phase rotating electric machine according to claim 1, wherein the controller is switched to a mode. A speed calculation processing unit that calculates a speed equivalent value that is one of a rotational speed of the three-phase rotating electrical machine and a correlation value thereof based on the detected time difference between the predetermined phases;
2. The control device for a three-phase rotating electrical machine according to claim 1, wherein the switching processing unit switches from the second mode to the first mode when the speed equivalent value is equal to or less than a specified speed. Without starting based on the detection of the predetermined phase, comprising a startup processing unit that starts the three-phase rotating electrical machine by operating the inverter,
The control device for a three-phase rotating electrical machine according to any one of claims 1 to 9, wherein the switching processing unit selects the first mode over a predetermined period after the processing of the activation processing unit is completed.