JP5196802B2 - Control device for rotating electrical machine - Google Patents

Description

  In controlling the rotating electrical machine by operating the switching element of the power conversion circuit, the present invention requires from a zero cross timing at which the induced voltage of the rotating electrical machine becomes a reference voltage to a specified timing as a reference for operating the switching element. The present invention relates to a control device for a rotating electrical machine that grasps time based on an interval of the zero cross timing.

  A technique for detecting the rotation angle of a three-phase motor based on a comparison between a terminal voltage of each phase of a three-phase motor as a multiphase rotating electrical machine and a reference voltage is well known. That is, for example, in a period in which no current flows in each phase of the three-phase motor, the terminal voltage becomes equal to the induced voltage. Then, the rotor angle (electrical angle: the same applies hereinafter) when the induced voltage becomes equal to the potential (reference voltage) at the connection point of each phase of the three-phase motor (zero crossing) is clearly determined. Therefore, the angle of the rotor can be grasped by detecting the induced voltage by means for detecting the terminal voltage.

  Specifically, for example, as can be seen in Patent Document 1 below, the time required for the rotor to rotate at a predetermined electrical angle interval is grasped from the interval of the zero crossing timing, and the timing at which the required time elapses from the timing of zero crossing is determined. The specified timing is an angle that serves as a reference for the switching operation.

Furthermore, in Patent Document 1, when setting the prescribed timing in the above manner when the three-phase motor is started, the prescribed timing is set by shortening the predetermined electrical angle interval used for calculating the required time. It is described that when the timing is calculated in the same manner as the normal time in the initial stage of startup, this timing is always delayed with respect to the timing that becomes the reference angle (paragraph “0041”).
JP-A-2005-333689

  By the way, when setting the specified timing by grasping the time required from the zero cross timing to the reference angle based on the interval of the zero cross timing as described above, the rotational speed of the motor is necessary to perform this setting with high accuracy. Have been found by the inventors to be stable. For this reason, not only when the motor is started, but also when the rotational speed fluctuates greatly, in general, the timing at which the reference angle is set cannot be set with high accuracy, and there is a risk that the controllability of the motor will be lowered.

  The present invention has been made in order to solve the above-described problems. The purpose of the present invention is to control a rotating electrical machine by operating a switching element of a power conversion circuit, regardless of fluctuations in rotational speed. An object of the present invention is to provide a control device for a rotating electrical machine capable of more appropriately grasping a timing at which a reference angle is based on a zero cross timing at which an induced voltage becomes a reference voltage.

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

According to the first aspect of the present invention, there is provided an extracting means for extracting information relating to a change in rotational speed of the rotating electrical machine from the detection result of the zero cross timing, and a period from the zero cross timing to the specified timing before and after the change in the rotational speed. order to the same electric angle change amount of the rotary electric machine according, e Bei and setting means for setting said prescribed timing based on the information, the extracting means, the rotation based on a plurality of values for intervals of the zero-cross timing It is means for calculating the acceleration of the electric machine, and the setting means is means for setting the specified timing using the acceleration as the information when starting the rotating electric machine .

  In the above invention, the zero-cross timing interval has a correlation with the rotational speed of the rotating electrical machine. For this reason, in steady state when the rotation speed of the rotating electrical machine is stable, the required time from a specific zero-cross timing to the specified timing should be calculated with high accuracy based on the rotation speed grasped from the zero-cross timing interval. Can do. However, when the rotational speed varies, the rotational speed at one zero cross timing interval may be different from the rotational speed at another zero cross timing interval. For this reason, in particular, there is a possibility that the rotational speed at the zero-cross timing interval referred to when setting the prescribed timing is different from the rotational speed immediately before the prescribed timing. In this case, if the required time from the specific zero cross timing to the specified timing is determined only by the interval of the zero cross timing before the specified timing, the rotational speed at the same interval is different from the rotational speed immediately before the specified timing. Doing so may leave you away from the true required time.

  On the other hand, when the rotational speed fluctuates, the detection result of the zero cross timing has a correlation with information regarding the fluctuation. In the above-mentioned invention, paying attention to this point, information on the change in the rotational speed of the rotating electrical machine is extracted from the zero cross timing. The information extracted in this way is information on the change in the rotation speed before the specified timing. From this change in the rotation speed, the rotation speed at the interval referred to when setting the specified timing and the rotation speed immediately before the specified timing are calculated. It is thought that the difference can be grasped. Therefore, based on this information, the required time from the specific zero cross timing to the specified timing can be calculated with high accuracy, and as a result, the specified timing can be set with high accuracy.

Note that it is desirable to extract the information from three or more zero cross timings. Thereby, since two or more intervals of zero cross timing can be acquired, it is possible to acquire two or more parameters having a correlation with the rotational speed that moves back and forth in time. For this reason, the information regarding the change in rotational speed can be acquired as the difference between the rotational speeds before and after the above.
Also, the zero cross timing interval has a correlation with the rotational speed of the rotating electrical machine. For this reason, the plurality of values for the interval include a plurality of pieces of rotational speed information at different times. In the above invention, focusing on this point, acceleration can be calculated from a plurality of values for the interval. For this reason, acceleration can be used as the information.
At the time of start-up, the change in the rotation speed is particularly remarkable. For this reason, at the time of starting, if the prescribed timing is determined based on the amount corresponding to the rotational speed grasped from the time interval between the zero cross timings, the timing tends to deviate from the timing at which the desired angle is obtained. In this regard, in the above invention, such a problem can be suitably avoided by using the setting means at the time of starting.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the setting of the specified timing based on the information is performed by advancing the specified timing as the amount of change on the increase side of the rotational speed is larger. To do.

  As the amount of increase in the rotational speed of the rotating electrical machine increases, the time required to reach the specified timing becomes shorter. In this regard, in the above invention, the specified timing can be set with high accuracy regardless of the fluctuation of the rotation speed by advancing the specified timing as the increase amount of the rotation speed is larger.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the setting means calculates a required time from the zero cross timing immediately before the specified timing to the specified timing from the interval of the zero cross timing. It comprises a calculating means and a correcting means for correcting the required time based on the information.

  In the above invention, by calculating the required time from the zero cross timing immediately before the specified timing to the specified timing from the interval of the zero cross timing, the required time can be calculated with high accuracy when the rotation speed of the rotating electrical machine is stable. Can do. By providing means for correcting the required time based on the above information, the required time can be calculated with high accuracy even when the rotational speed of the rotating electrical machine is fluctuating.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the power conversion circuit includes rectifying means connected in parallel to each switching element, and the rotating electrical machine Comparison means for comparing the magnitude relationship between the terminal voltage and the reference voltage, and invalidation means for invalidating the comparison by the comparison means over a predetermined period from the zero cross timing, wherein the zero cross timing is the comparison It is detected as a reversal timing of the comparison result of the means, and the extraction means acquires the information based on a time from the cancellation of the invalidation by the invalidation means to the zero cross timing.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the power conversion circuit includes a rectifying means connected in parallel to each switching element, and the rotating electrical machine Comparison means for comparing the magnitude relationship between the terminal voltage and the reference voltage, and invalidation means for invalidating the comparison by the comparison means over a predetermined period from the zero cross timing, wherein the zero cross timing is the comparison The required time is a time required from the zero cross timing immediately before the specified timing, and the previous zero cross timing has already passed when the invalidation is canceled by the invalidating means. The elapsed time from the previous zero cross timing to the present is estimated based on the induced voltage. And an estimation means.

  If the previous zero cross timing has already passed when the invalidation is canceled by the invalidating means, the zero cross timing cannot be detected, and therefore the time required from the detection of the zero cross timing to the specified timing cannot be calculated. On the other hand, after the invalidation is canceled, the terminal voltage becomes equal to the induced voltage, so that the induced voltage can be detected. The induced voltage includes information on the elapsed time from the zero cross timing to the current time. In the above invention, paying attention to this point, it is possible to calculate the required time from the zero cross timing to the specified timing by estimating the elapsed time based on the induced voltage.

According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the acceleration calculating means for calculating the acceleration of the rotating electrical machine based on a plurality of values for the interval of the zero cross timing, and the calculation. Limiting means for limiting the energization amount of the rotating electrical machine according to acceleration is further provided.

  The zero cross timing interval has a correlation with the rotation speed of the rotating electrical machine. For this reason, the plurality of values for the interval include a plurality of pieces of rotational speed information at different times. In the above invention, paying attention to this point, acceleration is calculated from a plurality of values for the interval. Here, for example, when the acceleration becomes excessive, the calculation accuracy of the required time based on the interval of the zero cross timing is lowered. In this regard, in the above invention, by limiting the amount of energization according to the acceleration, it is possible to suppress the acceleration so as to suppress a decrease in the calculation accuracy of the required time, and consequently, to set the specified timing with high accuracy. Can do.

  When controlling the rotating electrical machine by operating the switching element of the power conversion circuit, the time required from the zero cross timing at which the induced voltage of the rotating electrical machine becomes the reference voltage to the specified timing as the reference for the operation of the switching element, In a control apparatus for a rotating electrical machine that is grasped based on a zero-cross timing interval, an acceleration calculating unit that calculates an acceleration of the rotating electrical machine based on a plurality of values for the zero-cross timing interval, and the energization amount according to the calculated acceleration And a restricting means for restricting.

  The zero cross timing interval has a correlation with the rotation speed of the rotating electrical machine. For this reason, the plurality of values for the interval include a plurality of pieces of rotational speed information at different times. In the above invention, paying attention to this point, acceleration is calculated from a plurality of values for the interval. Here, for example, when the acceleration becomes excessive, the calculation accuracy of the required time based on the interval of the zero cross timing is lowered. In this respect, in the above-described invention, by limiting the energization amount according to the acceleration, it is possible to suppress the acceleration to such an extent that the calculation accuracy of the required time is not lowered, and thus the specified timing can be set with high accuracy. .

A sixth aspect of the present invention is the invention according to any one of the first to fifth aspects, wherein the rotating electrical machine is a multiphase rotating electrical machine, and from a phase of the rotating electrical machine prior to starting the rotating electrical machine. Positioning means for fixing a rotation angle of the rotating electrical machine to a predetermined angle by flowing a current through another partial phase, wherein at least one of the partial phase or the other partial phase is a plurality of phases. It is characterized by comprising.

  Since the induced voltage is generated by the rotation of the rotating electrical machine, it is difficult to detect the rotation angle based on the induced voltage of the rotating electrical machine when starting the rotating electrical machine. For this reason, it is well known to perform a so-called positioning process for fixing the rotation angle of the rotating electrical machine to a predetermined angle when starting the rotating electrical machine. However, when a current is passed from one phase of the rotating electrical machine to another phase during this positioning, the time until the rotational angle converges to a predetermined angle is prolonged, and there is a possibility that the starting of the rotating electrical machine is delayed.

  In this regard, in the above invention, a current is passed from one phase of the rotating electrical machine to another partial phase, and at least one of the partial phase or another partial phase is a plurality of phases. Thus, when the rotation angle of the rotating electrical machine deviates from a predetermined angle, a force for returning to the predetermined angle direction can be applied. For this reason, the convergence time to a predetermined angle can be shortened, and consequently the starting time of the rotating electrical machine can be shortened.

According to a seventh aspect of the present invention, prior to starting the rotating electrical machine, a current is passed from one phase of the rotating electrical machine to another phase to fix the rotating angle of the rotating electrical machine to a predetermined angle. A means is further provided, wherein at least one of the one part phase or the another part phase comprises a plurality of phases.

  Since the induced voltage is generated by the rotation of the rotating electrical machine, it is difficult to detect the rotation angle based on the induced voltage of the rotating machine when starting the rotating electrical machine. For this reason, it is well known to perform a so-called positioning process for fixing the rotation angle of the rotating electrical machine to a predetermined angle when starting the rotating electrical machine. However, when a current is passed from one phase of the rotating electrical machine to another phase during this positioning, the time until the rotational angle converges to a predetermined angle is prolonged, and there is a possibility that the starting of the rotating electrical machine is delayed.

  In this regard, in the above invention, a current is passed from one phase of the rotating electrical machine to another partial phase, and at least one of the partial phase or another partial phase is a plurality of phases. Thus, when the rotation angle of the rotating electrical machine deviates from a predetermined angle, a force for returning to the predetermined angle direction can be applied. For this reason, the convergence time to a predetermined angle can be shortened, and consequently the starting time of the rotating electrical machine can be shortened.

The invention according to claim 6 or 7 may be characterized in that the rotating electrical machine is a three-phase rotating electrical machine, as in the invention according to claim 8 .

The invention according to a ninth aspect is the invention according to any one of the sixth to eighth aspects, wherein the positioning means is configured to cause a current to flow from one phase to another phase of the rotating electrical machine. Short circuit means for short-circuiting all phases of the rotating electrical machine by bringing either the positive electrode side or the negative electrode side of the power source of the rotating electrical machine and all phases of the rotating electrical machine into a conductive state is provided.

  When either one of the positive electrode or the negative electrode and all the phases of the rotating electrical machine are brought into conduction, all the phases of the rotating electrical machine are short-circuited. In this case, a current flows through the rotating electrical machine due to the induced voltage associated with the rotation of the rotating electrical machine, and this current is attenuated by the influence of the resistance in the current path. In other words, the rotational energy is attenuated. In the above invention, paying attention to this point, the rotational energy of the rotating electrical machine can be rapidly reduced by making all phases of the rotating electrical machine conductive with either the positive electrode or the negative electrode of the power source. For this reason, the convergence time to a predetermined angle can be further shortened.

A tenth aspect of the present invention is the invention according to any one of the sixth to ninth aspects, wherein the positioning means performs a process of flowing a current from one phase of the rotating electrical machine to another partial phase. The rotation angle of the rotating electrical machine is fixed to the predetermined angle by performing a plurality of times while changing a part of the phase and the other part of the phase.

  Depending on the rotation angle of the rotating electrical machine when the rotating electrical machine is in a stopped state, even if a current is passed from a specific part of the phase to another specific part of the phase, little rotational torque may be generated. In this case, it is difficult to fix the rotation angle of the rotating electrical machine at a predetermined angle. In this regard, in the above-described invention, the process of flowing a current from a part of the phase to another part of the phase is performed a plurality of times while changing the part of the phase and the part of the other part of the phase. Securely fix. That is, even if the rotation angle at which no rotation torque is generated depending on the final process is the initial condition, the rotation torque is generated depending on the previous process, and therefore the rotation angle can be changed with respect to the initial condition. For this reason, it can fix reliably to a predetermined angle by the final process.

  At this time, the angle assumed to be fixed by the process before the change is set to an angle at which a predetermined or higher rotational torque can be generated by the subsequent process.

According to an eleventh aspect of the present invention, in the invention according to the tenth aspect , the positioning means causes the current to flow from the partial phase to the another partial phase, and then the partial phase and the separate phase. Prior to changing some of the phases, a process of short-circuiting all the phases of the rotating electrical machine is performed by bringing either the positive side or the negative side of the power source of the rotating electrical machine into conduction with all the phases of the rotating electrical machine. The apparatus further comprises means.

  When either one of the positive electrode or the negative electrode and all the phases of the rotating electrical machine are brought into conduction, all the phases of the rotating electrical machine are short-circuited. In this case, a current flows through the rotating electrical machine due to the induced voltage associated with the rotation of the rotating electrical machine, and this current is attenuated by the influence of the resistance in the current path. In other words, the rotational energy is attenuated. In the above invention, paying attention to this point, the rotational energy of the rotating electrical machine can be rapidly reduced by making all phases of the rotating electrical machine conductive with either the positive electrode or the negative electrode of the power source. For this reason, the convergence time of the rotation angle by the process other than the final process among the processes of passing the current through a part of the phase and another part of the phase can be shortened.

A twelfth aspect of the invention restricts the energization amount when the amount of current flowing through the rotating electrical machine becomes a predetermined value or more by the energization operation by the positioning means in the invention of any one of the sixth to eleventh aspects. It further has a limiting means.

  In the above invention, it is possible to avoid an excessive increase in power consumption due to the processing of the positioning unit by limiting the energization amount when the amount of current flowing through the rotating electrical machine exceeds a predetermined value by the energization operation by the positioning unit. it can. For this reason, it can suppress that the torque which arises by the process of a positioning means becomes excessive, and can shorten the convergence time of a rotation angle.

A thirteenth aspect of the present invention is the invention according to any one of the sixth to twelfth aspects, wherein the positioning means temporarily continues the state of the first switching operation accompanying the start of the rotating electrical machine at the predetermined angle. The angle from the advanced angle side from the angle delayed by “180 °” with respect to the convergence value of the rotation angle of the rotating electrical machine to the retard angle side from the angle advanced by “30 °” with respect to the convergence value It is set to an area.

  According to the setting of the predetermined angle, the starting time can be shortened.

The invention according to claim 14 is the invention according to any one of claims 1 to 13 , wherein the rotating electrical machine is mounted on an in-vehicle engine system, and a voltage of a power source of the rotating electrical machine is predetermined. The apparatus further includes standby means for waiting for the rotating electric machine to start until the voltage exceeds a specified voltage.

  When the voltage of the power source is low, the switching operation by the control device may not be performed properly. And if switching operation cannot be performed appropriately, starting cannot be performed appropriately. On the other hand, in the power source of the in-vehicle engine system, the voltage tends to temporarily decrease at the start. In this respect, in the above-described invention, the start of the rotating electrical machine is awaited until the voltage of the power source becomes equal to or higher than the specified voltage, so that such a problem can be avoided.

The invention according to any one of claims 1 to 14 may be characterized in that, as in the invention according to claim 15 , the rotating electrical machine is an actuator of a fuel pump.

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

  FIG. 1 shows an overall configuration of a brushless motor control device according to the present embodiment.

  The illustrated brushless motor 10 is a three-phase motor and is an actuator of a fuel pump of an internal combustion engine mounted on a motorcycle. An inverter 12 is connected to the three phases (U phase, V phase, W phase) of the brushless motor 10. This inverter 12 is a three-phase inverter, and appropriately applies the voltage on the battery 14 side to the three phases of the brushless motor 10. Specifically, the inverter 12 switches between the switching elements SW1 and SW2 (U-phase leg) and the switching elements SW3 and SW4 (V-phase leg) so as to conduct each of the three phases and the positive electrode side or the negative electrode side of the battery 14. It is configured to include a parallel connection body with the elements SW5 and SW6 (W-phase legs). And the connection point which connects switching element SW1 and switching element SW2 in series is connected with the U phase of the brushless motor 10. FIG. In addition, a connection point where the switching elements SW3 and SW4 are connected in series is connected to the V phase of the brushless motor 10. Furthermore, a connection point for connecting the switching element SW5 and the switching element SW6 in series is connected to the W phase of the brushless motor 10. Further, flywheel diodes D1 to D6 are connected in parallel to the switching elements SW1 to SW6, respectively.

  In the present embodiment, the switching elements SW1, SW3, SW5 on the upper side (upper arm) of each leg are configured by P-channel MOS transistors, and the switching elements SW2, SW4 on the lower side (lower arm) of each leg. , SW6 are composed of N-channel MOS transistors. The flywheel diodes D1 to D6 are configured as parasitic diodes of the MOS transistor.

  The control device 20 controls the output of the brushless motor 10 by operating the inverter 12. Specifically, the control device 20 includes a driver 22, a current detection unit 24, and a switching control unit 26. Here, the current detection unit 24 is a part that detects currents flowing through the switching elements SW <b> 1 to SW <b> 6 and outputs the currents to the switching control unit 26. Specifically, in the present embodiment, the current flowing through the switching elements SW1 to SW6 is detected based on these on-resistances. That is, the current detection unit 24 includes a detection transistor for detecting a current flowing through each of the switching elements SW1 to SW6. And about the switching elements SW1-SW6 and the corresponding detection transistor, a current mirror circuit is comprised by short-circuiting these sources and gates. Thereby, the current flowing through the switching elements SW1 to SW6 can be detected based on the output current of the detection transistor. Actually, the current detection unit 24 is preferably formed in the vicinity of the inverter 12. Incidentally, for example, Japanese Patent Laid-Open No. 10-256541 discloses a method for detecting a current by forming a current mirror circuit.

  The switching control unit 26 turns on / off the switching elements SW <b> 1 to SW <b> 6 via the driver 22. Here, basically, switching control is performed by a 120 ° energization method. Specifically, the timing (zero cross) at which the induced voltage becomes the neutral point voltage (reference voltage vref) of the brushless motor 10 by using the timing at which the terminal voltages vu, vv, vw of each phase of the brushless motor 10 coincide with the induced voltage. Timing). Then, the operation of the switching elements SW1 to SW6 is switched at a timing (specified timing) delayed by a predetermined electrical angle (for example, “30 °”) from the zero cross timing. However, when the current detected by the current detector 24 exceeds the current limit value, PWM control is performed to limit the current (energization amount) flowing through the brushless motor 10. In this PWM control, a period of “120 °” in which the switching elements SW1 to SW6 are turned on in the 120 ° energization method is set as an on operation permission period, and the on operation is performed when the current limit value is exceeded even within this period. It can be done by prohibiting.

  The switching control unit 26 may be configured by a logic circuit, or may be configured by a central processing unit and a storage device that stores a program.

  In FIG. 2, the switching control aspect by the switching control part 26 at the time of 120 degree electricity supply control is shown. Specifically, in FIG. 2A, the transition of the U-phase terminal voltage is indicated by a solid line, the transition of the induced voltage of the U-phase is indicated by a two-dot chain line, and the reference voltage vref is indicated by a one-dot chain line. FIG. 2 (b) shows the transition of the signal related to the detection of the zero cross timing (zero cross detection signal), FIG. 2 (c) shows the transition of the operation signal of the switching element SW1, and FIG. The transition of the operation signal of the switching element SW2 is shown. Since the V-phase and W-phase are the same as the U-phase switching control mode, description and description thereof are omitted.

  As shown in the figure, when the switching elements SW1 and SW2 are in the on state, the terminal voltage vu matches the potential on the positive electrode side or the potential on the negative electrode side of the battery 14. On the other hand, in the period in which both the switching element SW1 and the switching element SW2 are in the off state (induced voltage exposure period), there is a period in which no current flows in the U phase. At this time, the terminal voltage vu is Become. However, even in a period in which both the switching element SW1 and the switching element SW2 are in the OFF state, the terminal voltage does not match the induced voltage in a state where current flows through the diodes D1 and D2 (commutation transient state).

  For this reason, the timing at which the terminal voltage vu and the reference voltage vref coincide with each other in the period in which both the switching element SW1 and the switching element SW2 are in the OFF state and no current flows in the diodes D1 and D2 is the induced voltage. The zero cross timing coincides with the reference voltage vref. For this reason, the timing delayed by a predetermined electrical angle (for example, “30 °”) from the zero cross timing is defined as the specified timing, the switching element SW1, SW2 is switched from the OFF operation to the ON operation, and the ON state is 120 ° from the specified timing. Continue for a period of. Specifically, the specified timing delayed by a predetermined electrical angle (for example, “30 °”) from the zero cross timing that coincides with the reference voltage vref in the process of increasing the induced voltage is set as the timing for switching the switching element SW1 of the upper arm to the ON state. Further, the specified timing delayed by a predetermined electrical angle (for example, “30 °”) from the zero cross timing that coincides with the reference voltage vref in the process of decreasing the induced voltage is set as the timing for switching the switching element SW2 of the lower arm to the ON state. As described above, the switching timing of the U-phase switching elements SW1 and SW2 to the on state can be determined by the zero-cross timing in the rising process of the U-phase induced voltage and the zero-crossing timing in the falling process. For this reason, in the present embodiment, a zero cross detection signal that falls at the zero cross timing in the rising and falling process is generated at the zero cross timing in the rising process, and the rising and falling edges are used when setting the specified timing.

  FIG. 3 shows a switching control mode in a steady state where the rotation speed of the brushless motor 10 is stable. Specifically, FIG. 3A shows the transition of the terminal voltages vu, vv, and vw, FIG. 3B shows the transition of the comparison signal of the magnitude relationship between the terminal voltage and the reference voltage vref, and FIG. FIG. 3C shows the transition of the zero cross detection signal, FIG. 3D shows the transition of the values of the various counters, and FIG. 3E shows the transition of the operation signal of the switching elements SW1 to SW6. 3 (e) includes operation signals U +, V +, W + of the upper arm switching elements SW1, SW3, SW5, and operation signals U− of the lower arm switching elements SW2, SW4, SW6, V- and W- are shown. Since the switching elements SW1, SW3, and SW5 of the upper arm are P-channel transistors, the period in which these operation signals U +, V +, and W + are in the logic “L” period is the on-period.

  In FIG. 3D, a solid line indicates the value of a measurement counter that measures the interval between adjacent zero-cross timings. As shown in the figure, the measurement counter is initialized every time the zero cross timing is reached, and newly restarts the timing operation. Here, the interval between the zero cross timings adjacent to each other has a correlation with the rotation speed. Therefore, the value of the measurement counter immediately before initialization (maximum value of the measurement counter) is a parameter having a correlation with the rotation speed.

  On the other hand, what is indicated by a one-dot chain line in FIG. 3D is a value of a specified timing setting counter that sets the specified timing by counting the required time from the zero cross timing to the specified timing. The specified timing setting counter sets, as a specified timing, a timing that becomes zero by decrementing a value before initialization of the measurement counter as an initial value at the zero cross timing. At this time, if the interval between the zero cross timing and the specified timing is “30 °”, the decrement speed is set to twice the increment speed of the measurement counter. This is because the interval between the zero cross timings adjacent to each other is “60 °”. For this reason, if the rotational speed is constant, the timing at which the specified timing setting counter becomes “0” should be equal to the timing delayed by “30 °” from the zero cross timing.

  Also, a two-dot chain line in FIG. 3D shows a period during which the detection of the zero cross timing based on the magnitude comparison between the terminal voltages vu, vv, vw and the reference voltage vref is prohibited (invalidated) (masking period) The value of the masking period counter that defines This counter is for avoiding erroneous determination that the terminal voltage vu, vv, vw coincides with the reference voltage vref during the period in which current flows through the diodes D1 to D6, and that it is the zero cross timing. This counter also decrements a value before initialization of the measurement counter as an initial value at the zero cross timing, and sets a period until it becomes zero as a masking period. Here, if the masking period is a period of “45 °” from the zero cross timing, the decrement speed is set to “3/2” times the increment speed of the measurement counter.

  Hereinafter, the processing procedure of the switching control according to the present embodiment will be further described with reference to FIGS. 4 and 5. FIG. 4 shows a procedure for setting the counter values of the three counters. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processing, first, in step S10, it is determined whether or not the masking period counter is “0”. If it is determined to be zero, it is determined in step S12 whether any of the comparison signals Uc, Vc, Wc is inverted. This process is actually a process of determining whether or not it is the timing of the rising edge or the falling edge of the zero cross detection signal. When it is determined in step S12 that one of them is reversed, in step S14, the values of the specified timing setting counter and the masking period counter are set as the values of the measurement counter. In step S16, the measurement counter is initialized.

  On the other hand, when a negative determination is made in steps S10 and S12, the measurement counter is incremented in step S18. In a succeeding step S20, it is determined whether or not the specified timing setting counter is zero. If the specified timing setting counter is not zero, the specified timing setting counter is decremented in step S22. On the other hand, when an affirmative determination is made in step S20 or when the process of step S22 is completed, it is determined in step S24 whether the masking period counter is zero. If the masking period counter is not zero, the masking period counter is decremented in step S26.

  When an affirmative determination is made at step S24 or when the processing of steps S16 and S26 is completed, this series of processing is temporarily terminated.

  FIG. 5 shows a processing procedure for switching the switching elements SW1 to SW6 to the ON state. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processes, first, in step S30, it is determined whether or not the specified timing setting counter is zero. This process is to determine whether or not the prescribed timing has come. Then, when it is determined that the specified timing setting counter has become zero, a process of switching any one of the switching elements SW1 to SW6 to the on state is performed. That is, when the zero-cross timing at which the value of the specified timing setting counter is set to the value of the measurement counter is the U-phase zero-cross timing (step S32: YES) and the zero-cross detection signal rises (step S34: YES), switching is performed. The element SW1 is switched on (step S36), and when the zero-cross detection signal falls (step S34: NO), the switching element SW2 is switched on (step S38).

  On the other hand, when the zero-cross timing is the V-phase zero-cross timing (step S40: YES) and the zero-cross detection signal rises (step S42: YES), the switching element SW3 is switched on (step S44). When the detection signal falls (step S42: NO), the switching element SW4 is switched on (step S46). Further, when the zero-cross timing is the W-phase zero-cross timing (step S40: NO) and the zero-cross detection signal rises (step S48: YES), the switching element SW5 is switched on (step S50). When the detection signal falls (step S48: NO), the switching element SW6 is switched on (step S52).

  Note that the method of switching the switching elements SW1 to SW6 to the OFF state is also a timing that is delayed by a predetermined electrical angle (for example, “30 °”) from a specific specified timing (see FIG. 3 above). More specifically, the switching elements SW1, SW3, SW5 of the upper arm are switched to the OFF state at a timing delayed by a predetermined electrical angle from the zero cross timing in the rising process of the induced voltage of the phase different from itself, and the predetermined electrical angle from the zero cross timing in the descending process. The switching elements SW2, SW4, SW6 of the lower arm are switched to the OFF state at the retarded timing. Since this can be performed in the same manner as the processing of FIG. 5, the description thereof is omitted here.

  By the way, as illustrated in the case of acceleration in FIG. 6, the zero cross timing depends on the rotation speed of the brushless motor 10. For this reason, when the rotational speed of the brushless motor 10 fluctuates, depending on the value of the measurement counter immediately before initialization, the rotational speed of the zero cross timing at the time of initialization and the interval of the next zero cross timing can be expressed with high accuracy. Can not do it. For this reason, the timing at which the specified timing setting counter becomes zero may be shifted from the specified timing.

  FIG. 7 shows an experimental result of the setting error of the specified timing at the time of acceleration as an example when the rotational speed fluctuates. When accelerating from an initial speed of zero to a predetermined speed as shown in FIG. 7A, a rotor angle detection error (phase shift) occurred as shown in FIG. 7B. As shown in the figure, during acceleration, the deviation is particularly large in the low speed region.

  Therefore, in the present embodiment, information related to a change in the rotational speed of the brushless motor 10 is extracted from the detection result of the zero cross timing, and the specified timing is set based on this information. That is, although the change in the rotational speed in the above information is in a period before the specified timing, the difference between the rotational speed in the interval between adjacent zero cross timings immediately before the specified timing and the rotational speed immediately before the specified timing is grasped. It can be used for this purpose. Therefore, the specified timing is set while grasping the difference based on the information.

  FIG. 8 shows a processing procedure for setting the prescribed timing 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 processing, it is determined in step S60 whether or not masking is being canceled. That is, it is determined whether or not the masking period counter is zero. When it is time to cancel masking, the acceleration detection counter is incremented in step S62. On the other hand, in step S64, it is determined whether any of the comparison signals Uc, Vc, Wc is inverted, as in step S12 of FIG. When an affirmative determination is made in step S64, it is determined in step S66 whether or not the acceleration detection counter value is equal to or smaller than a predetermined value α. This process is for determining whether or not the brushless motor 10 is in an accelerated state. Here, if the masking period is the period from the zero cross timing to “45 °” and the increment speed of the acceleration detection counter is the same as the increment speed of the measurement counter, the value of the acceleration detection counter is the previous measurement counter. When the value is smaller than “¼” times the value of the brushless motor 10, it can be determined that the brushless motor 10 is in an acceleration state. Therefore, in this case, the predetermined value α is set to a value smaller than a value that is “¼” times the previous measurement counter value.

  When it is determined in step S66 that the vehicle is in the acceleration state, in step S68, a correction amount Δ for correcting the specified timing setting counter value is set according to the value of the acceleration detection counter. Here, as shown in the lower part of the figure, the correction amount Δ is set to a large value in view of the fact that the acceleration increases as the acceleration detection counter value decreases. In the subsequent step S70, the specified timing setting counter value is set to a value obtained by subtracting the correction amount Δ from the specified timing setting counter value.

  When a negative determination is made in step S66 or when the process of step S70 is completed, an acceleration detection counter is initialized in step S72. When a negative determination is made in steps S60 and S64, or when the process of step S72 is completed, this series of processes is temporarily terminated.

  FIG. 9 shows a mode of output control of the brushless motor during acceleration according to the present embodiment. Specifically, FIG. 9A shows the change of the rotor angle, FIG. 9B shows the change of the rotation speed, and FIG. 9C shows the change of the phase current. As shown in the figure, since the detection error of the specified timing is small even during acceleration, the rotational speed can be smoothly increased to a desired rotational speed. On the other hand, when the measurement counter correction process shown in FIG. 8 is not performed, as shown in FIG. 10, there is a large error in the prescribed timing, and the rotation speed cannot be increased smoothly. Incidentally, FIGS. 10A to 10C correspond to FIGS. 9A to 9C.

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

  (1) Information relating to the change in the rotational speed of the brushless motor 10 is extracted from the detection result of the zero cross timing, and based on this, the prescribed timing is set. Therefore, the required time from the specific zero-cross timing to the specified timing (value of the specified timing setting counter) can be calculated with high accuracy, and the specified timing can be set with high accuracy.

  (2) The required time from the zero cross timing immediately before the specified timing to the specified timing (the initial value of the specified timing setting counter) is calculated from the interval of the zero cross timing (the value of the measurement counter), and based on the above information, Corrected. Thereby, even when the rotational speed is fluctuating, the required time (the initial value of the specified timing setting counter) can be calculated with high accuracy.

  (3) The above information was acquired based on the time from the release of masking to the zero cross timing. Thereby, the said information can be acquired appropriately.

  (4) The specified timing was advanced as the time until the zero cross timing was reached. Thereby, the specified timing can be set with high accuracy according to the magnitude of the acceleration.

(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 acceleration of the brushless motor 10 is calculated from the detection result of the zero cross timing, and the specified timing is variably set according to the acceleration.

  FIG. 11 shows a processing procedure for setting the prescribed timing 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 processing, in steps S80 and S82, it is determined whether or not it is the zero cross timing by performing the processing in steps S10 and S12 of FIG. If it is the zero cross timing, a process of calculating the acceleration Ai is performed in step S84. Here, the difference between the reciprocal N (i) of the time interval from the previous zero cross timing to the current zero cross timing and the reciprocal N (i-1) of the time interval from the previous previous zero cross timing to the previous zero cross timing. Acceleration Ai is calculated. In practice, this process may be calculated by subtracting the inverse of the maximum value of the previous measurement counter from the inverse of the maximum value of the current measurement counter.

  In the subsequent step S86, a correction amount Δ for correcting the specified timing setting counter is calculated according to the calculated acceleration Ai. Here, as shown in the lower part of FIG. 11, when the acceleration Ai is equal to or larger than a predetermined value β (> 0), the correction amount Δ is set to a negative value having a larger absolute value as the acceleration Ai is larger. On the other hand, when the acceleration Ai is equal to or less than the predetermined value α (<0), the correction amount Δ is set to a positive value having a larger absolute value as the acceleration Ai is smaller.

  In the subsequent step S88, the specified timing setting counter is corrected by adding the correction amount Δ to the specified timing setting counter. When a negative determination is made in steps S80 and S82, or when the process of step S88 is completed, this series of processes is temporarily terminated.

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

  (5) The acceleration of the brushless motor 10 was calculated based on a plurality of values for the zero-cross timing interval, and the prescribed timing was set based on this. Thereby, the specified timing can be set with high accuracy regardless of the fluctuation of the rotation speed.

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

  When the zero cross timing is reached before the masking period counter becomes zero, it is impossible to set the specified timing properly, or to set the masking period counter and the like appropriately. Therefore, in the present embodiment, under such circumstances, the elapsed time from the zero cross timing to the present is estimated based on the induced voltage at that time.

  FIG. 12 shows the procedure of the processing relating to the above estimation. 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 the masking period counter is at the time of masking cancellation in which the counter changes to zero. If it is time to cancel masking, it is determined in step S92 whether the zero cross timing has already been passed. This process determines whether or not the terminal voltage has already exceeded the reference voltage vref when the induced voltage is in the process of increasing, and if the terminal voltage is already below the reference voltage vref when the voltage is in the process of decreasing the induced voltage. This can be done by determining whether or not.

  When it is determined that the zero cross timing has already been passed, the process proceeds to step S94. In step S94, the elapsed time from the zero cross timing to the present is estimated based on the previous measurement counter value and the terminal voltage. Here, the terminal voltage indicates an induced voltage when masking is released. The difference between the induced voltage value and the reference voltage vref includes information on the elapsed time. However, since the amplitude of the induced voltage depends on the rotation speed, the elapsed time cannot be grasped with high accuracy only by the current induced voltage. Therefore, in the present embodiment, the elapsed time is estimated based on the maximum value of the previous measurement counter as a parameter having a correlation with the rotation speed and the current induced voltage. Here, for example, the switching control unit 26 is configured by a microcomputer, and the elapsed time is estimated using a map that defines the relationship between the maximum value of the previous measurement counter and the current induced voltage and the elapsed time. That's fine.

  In step S96, the specified timing setting counter and the masking period counter are set to values obtained by subtracting the elapsed time from the current measurement counter value. This process is a process for setting a prescribed timing and a masking period based on the estimated zero cross timing. In step S98, the measurement counter is set to the elapsed time.

  When an affirmative determination is made in steps S90 and S92, or when the process of step S98 is completed, this series of processes is temporarily terminated.

  According to this embodiment described above, the following effects can be obtained in addition to the effects (1) to (4) of the first embodiment.

  (6) When the previous zero cross timing has already passed when the masking is released, the elapsed time from the previous zero cross timing to the present is estimated based on the induced voltage. As a result, the required time from the immediately preceding zero cross timing to the specified timing can be estimated.

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

  In the present embodiment, the limit value of the current flowing through the switching elements SW <b> 1 to SW <b> 6 is variably set according to the acceleration of the brushless motor 10. FIG. 13 shows a procedure for setting the current limit value. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processing, first, in step S100, acceleration Ai is calculated. This process is the same as the process in step S84 of FIG. In the subsequent step S102, it is determined whether or not the acceleration Ai is equal to or greater than the first specified acceleration Amax. Here, the first specified acceleration Amax is set in accordance with an excessive acceleration at which a decrease in setting accuracy of the specified timing based on the zero cross timing interval becomes significant. If it is determined that the acceleration is equal to or greater than the first specified acceleration Amax, the current limit value is reduced by ΔA (> 0) in step S104. This is a process for reducing the acceleration of the brushless motor 10.

  On the other hand, if it is determined that the acceleration is less than the first specified acceleration, it is determined in step S106 whether the acceleration is equal to or less than the second specified acceleration. Here, the second specified acceleration Amin is set in accordance with an excessive acceleration (excessive deceleration) at which a decrease in the accuracy of setting the specified timing based on the zero cross timing interval becomes significant. When it is determined that the acceleration is equal to or less than the second specified acceleration Amin, the current limit value is increased by ΔB (> 0) in step S108. This is a process for reducing the absolute value of the acceleration of the brushless motor 10.

  As described above, in the present embodiment, the processing for reducing the absolute value of the acceleration is performed by performing the process for reducing the absolute value of the acceleration in a situation where the setting accuracy of the specified timing is remarkably reduced due to the absolute value of the acceleration being excessively increased. Improve the setting accuracy. Such a setting is particularly effective for a setting in which the rotational speed is simply controlled by energizing basically by the 120 ° energization method as in this embodiment. That is, in this case, the acceleration is determined by a load applied to the output shaft of the brushless motor 10 and varies depending on the situation. For example, when the fuel viscosity of the fuel pump is low, since the load applied to the output shaft of the brushless motor 10 is small, the acceleration may be excessively large at the time of startup or the like. On the other hand, when it is adapted so that the acceleration does not become excessively large in a situation where the viscosity of the fuel is low, the start-up time is extended in a situation where the viscosity of the fuel is high. In this way, it is difficult to avoid an excessive increase in acceleration due to the demand for shortening the startup time.

  When the current flowing through the switching elements SW1 to SW6 exceeds the current limit value, PWM control is performed instead of turning on the switching elements SW1 to SW6 for a period of 120 °. SW6 is switched between an on state and an off state within a period of 120 ° from the specified timing. At this time, the timing at which the switching elements SW1 to SW6 are first turned on and the timing at which the switching elements SW1 to SW6 are finally turned off do not necessarily coincide with the specified timing.

  In addition, when the switching elements SW1 to SW6 are turned on / off by PWM control, a period in which the terminal voltages vu, vv, vw and the reference voltage Vref do not coincide with each other due to current flowing through the diodes D1 to D6 is newly generated. , Additionally set the masking period.

  According to the embodiment described above, the following effects can be obtained in addition to the effects (1) to (4) of the first embodiment.

  (7) The current limit value is variably set according to the acceleration. Thereby, the increase in the absolute value of the acceleration can be suppressed to such an extent that the calculation accuracy of the required time based on the zero cross timing interval is not excessively lowered. For this reason, it is possible to set the specified timing with higher accuracy by using the information related to the change in the rotation speed.

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

  The induced voltage of the brushless motor 10 is generated as the brushless motor 10 rotates. For this reason, when the brushless motor 10 is in a stopped state, a switching operation based on the induced voltage cannot be performed when the brushless motor 10 is started. Therefore, when the brushless motor 10 is started, as shown in FIG. 14A, a so-called positioning process for fixing the rotor angle (electrical angle) by flowing a current from a specific phase to another specific phase is performed. It was made. In FIG. 5, by turning on the switching element SW1 of the upper arm and the switching element SW6 of the lower arm, a current flows from the U phase to the W phase, thereby fixing the rotor angle of the brushless motor 10. An example is shown. When the angle of the rotor is fixed by this process, it may take a long time for the angle of the rotor to converge. For this reason, the start time of the brushless motor 10 may be prolonged.

  Therefore, in the present embodiment, as shown in FIG. 14B, the one-phase switching element of the upper arm and the two-phase switching element of the lower arm of the brushless motor 10 are turned on to start from one phase. Current is passed through the two phases (one-phase and two-phase energization), and the rotor angle of the brushless motor 10 is fixed to a predetermined angle. FIG. 14B illustrates a case where a current flows from the U phase to the V phase and the W phase by turning on the upper arm switching element SW1 and the lower arm switching elements SW4 and SW6. Yes. Thereby, since the force of the side which reduces the shift | offset | difference with respect to the predetermined angle of the angle of the rotor of the brushless motor 10 comes to act, the convergence time to a predetermined angle can be shortened.

  FIG. 15A shows a manner of convergence of the rotor angle by the positioning process of FIG. 14A, and FIG. 15B shows a manner of convergence of the rotor angle by the positioning process of FIG. 14B. Show. As shown in the figure, according to the positioning process according to the present embodiment, since the convergence time of the rotor angle is short, the fluctuation of the current correlated with the fluctuation of the rotor angle is settled early.

  Next, the predetermined angle setting method according to the present embodiment will be described. FIG. 16 shows the relationship between the predetermined angle and the starting time. Here, the angle “0 °” is set to an angle that is assumed to converge when the initial switching operation state at the start of the brushless motor 10 is continued. Further, the drawing shows the start time for the case where the current flowing through the brassless motor 10 is not limited and the case where it is limited during the positioning process.

  As shown in the drawing, if the predetermined angle is set to a region that is more advanced than the angle that is retarded by “150 °” and is more retarded than the angle that is advanced by “30 °”, the start is performed well. be able to. This is related to the relation shown in FIG. 17 between the torque generated at the start of the switching operation accompanying the start of the brushless motor 10 and the predetermined angle. Here, the positive torque means that the brushless motor 10 is rotated in the positive direction. As shown in the drawing, in the advance side region, torque that reversely rotates the brassless motor 10 is generated, and therefore the brushless motor 10 is likely to reversely rotate. On the other hand, the output torque becomes maximum at an angle delayed by “60 °”. For this reason, as shown in FIG. 16 above, in the vicinity of the angle delayed by “60 °”, the starting time is particularly shortened regardless of whether or not the current flowing through the brushless motor 10 is limited during the positioning process. Can do. For this reason, in this embodiment, a predetermined angle is set in the vicinity of the angle delayed by “60 °”.

  FIG. 18 shows a processing procedure for starting the brushless motor 10 according to the present embodiment. This process is executed by the control device 20 triggered by turning on the ignition switch.

  In this series of processing, when the ignition switch is turned on, first, in step S110, the positioning processing by the above-described one-phase two-phase energization is performed. In step S112, it is determined whether or not a predetermined time Tdi has elapsed since the start of the positioning process. The predetermined time Tdi is set to a time as short as possible, which is equal to or longer than the time when the rotor angle converges to the predetermined angle by the one-phase and two-phase energization. When the predetermined time Tdi elapses, the positioning process is terminated in step S114. That is, the on operation of one phase of the upper arm and the two phases of the lower arm is stopped, and these are switched to the off operation state. In step S116, the brushless motor 10 is started. In addition, the process of step S114 is good also as a process which switches the switching operation state for the said 1 phase 2 phase electricity supply to the first state of the switching operation accompanying the starting of the brushless motor 10. FIG.

  When the process of step S116 is completed, this series of processes is temporarily terminated.

  According to this embodiment described above, the following effects can be obtained in addition to the effects (1) to (4) of the first embodiment.

  (8) Prior to starting the brushless motor 10, the angle of the rotor of the brushless motor 10 is fixed at a predetermined angle by flowing current from one phase of the brushless motor 10 to another two phases. Thereby, the convergence time to a predetermined angle can be shortened, and by extension, the starting time of the brushless motor 10 can be shortened.

  (9) The predetermined angle is in the vicinity of an angle delayed by “60 °” with respect to the convergence value of the rotor angle of the brushless motor 10 when the initial switching operation state accompanying the start of the brushless motor 10 is continued. Set. As a result, a large rotational torque in the positive direction can be generated by the first switching operation, and thus the starting time can be shortened.

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

  When performing the positioning process by the above-described one-phase two-phase energization, there is a case where the rotational torque cannot be generated by the one-phase two-phase energization depending on the stop position of the brushless motor 10 before starting the positioning process. That is, as can be seen from FIG. 17, when the predetermined angle and the stop position are shifted by “180 °”, no rotational torque is generated. For this reason, in such a case, there is a possibility that positioning may not be performed properly depending on the above processing.

  Therefore, in the present embodiment, the positioning process is performed by performing one-phase two-phase energization twice. FIG. 19 shows a procedure for starting the brushless motor 10 according to the present embodiment. This process is executed by the control device 20 with the ignition switch being turned on as a trigger.

  In this series of processing, first, in step S120, provisional positioning processing by one-phase two-phase energization is performed. Here, a process of fixing at an angle different from the predetermined angle is performed. Then, when the predetermined time Tdi elapses (step S122: YES), the temporary positioning process is ended in step S124. In the subsequent step S126, final positioning processing, that is, positioning processing to a predetermined angle is performed by one-phase two-phase energization. Here, as in the first embodiment, the predetermined angle is “60 °” retarded based on the convergence value of the rotor angle when the initial switching operation state at the start of the brushless motor 10 is continued. Near the angle. The angle difference between the angle fixed by the temporary positioning process and the angle fixed by the final positioning process is set to be larger than “0 °” and smaller than “180 °”. More desirably, the angle difference is set to be approximately “60 °”. When the final positioning process time reaches the predetermined time Tdi, the final positioning process is terminated in step S130. In step S132, the brushless motor 10 is started.

  According to the above process, even if the difference between the rotor angle of the brushless motor 10 and the predetermined angle is “180 °”, the brushless motor 10 is rotated by the temporary positioning process, The difference can be less than “180 °”. For this reason, the angle of the rotor of the brushless motor 10 can be reliably fixed to a predetermined angle by the final positioning process. When the angle of the rotor of the brushless motor 10 before the start of the positioning process is an angle at which no rotational torque is generated by the temporary positioning process, this angle is an angle at which the rotational torque is generated by the final positioning process. For this reason, it can be rotated to a predetermined angle by a final positioning process.

  Note that the predetermined time Tdi in step S128 is shorter than the predetermined time Tdi in step S112 of FIG. 18 by making the difference between the fixed angle and the predetermined angle by the temporary positioning process close to “60 °”. Is possible. This is because the rotational torque generated in the brushless motor 10 when starting the final positioning process increases, and the time required to move from the angle fixed by the temporary positioning process to a predetermined angle is shortened. is there.

  According to this embodiment described above, the following effects can be obtained in addition to the effects (8) to (9) of the fifth embodiment.

  (10) The angle of the rotor of the brushless motor 10 was fixed to a predetermined angle by performing the one-phase two-phase energization twice while changing the fixing position. Thereby, it can fix reliably to a predetermined angle irrespective of the angle of the rotor of the brushless motor 10 before a positioning process.

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

  FIG. 20 shows a procedure for starting the brushless motor 10 according to the present embodiment. This process is executed by the control device 20 with the ignition switch being turned on as a trigger. In FIG. 20, the same step numbers are assigned to the processes corresponding to those in FIG.

  In this series of processing, when it is determined in step S112 that the predetermined time Tdis has elapsed, in step S140, the upper arm switching elements SW1, SW3, SW5 or the lower arm switching elements SW2, SW4, SW6 are all turned on. Perform all-phase short-circuit processing to make the state. When the all-phase short-circuit process is performed for a predetermined time Ts (step S142: YES), the brushless motor 10 is activated.

  According to the all-phase short-circuit process, a current flows through the brushless motor 10 due to an induced voltage associated with the rotation of the brushless motor 10, and this current is attenuated by the influence of the resistance in the current path. In other words, the rotational energy is attenuated. For this reason, the brushless motor 10 can be stopped more quickly at a predetermined angle. The predetermined time Ts is set to a time as short as possible and longer than the time when vibration is attenuated so that the brushless motor 10 converges to a predetermined angle by the all-phase short-circuiting process and is substantially stopped.

  According to the above process, it is not necessary to determine the predetermined time Tdis in step S112 according to the time until the rotor angle of the brushless motor 10 converges to the predetermined angle, and the time required to shift to the predetermined angle. Can be determined according to For this reason, the predetermined time Tdis can be shorter than the predetermined time Tdi in step S112 of FIG.

  According to this embodiment described above, the following effects can be obtained in addition to the effects (8) to (9) of the fifth embodiment.

  (11) All phases of the brushless motor 10 were short-circuited after the 1-phase 2-phase energization process. Thereby, the convergence time to a predetermined angle can further be shortened.

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

  FIG. 21 shows a procedure for starting the brushless motor 10 according to the present embodiment. This process is executed by the control device 20 with the ignition switch being turned on as a trigger. In FIG. 20, processes corresponding to those in FIG. 19 are given the same step numbers for convenience.

  In this series of processing, when one-phase two-phase energization for temporary positioning processing is performed for a predetermined time Tdis (step S122: YES), one-phase two-phase energization for final positioning processing is performed for a predetermined time Tdis. When performed (step S128: YES), all-phase short-circuit processing is performed (steps S144 and S146). Thereby, it is possible to shorten the time required for positioning as compared with the previous sixth embodiment.

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

  As described above, when the current flowing through the switching elements SW <b> 1 to SW <b> 6 exceeds a predetermined value by 120 ° energization control, PWM control is performed so as to limit this. In the present embodiment, PWM control is also performed when the current flowing through the switching elements SW1 to SW6 is greater than or equal to a predetermined value during the positioning process.

  FIG. 22 shows a processing procedure of current limit control 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 S150, it is determined whether or not the positioning process is being performed. If it is determined that it is during the positioning process, it is determined in step S152 whether or not the amount of current of the switching elements SW1, SW3, SW5 of the upper arm is greater than or equal to the threshold current ε. This process determines whether or not the amount of current during the positioning process is excessive. If it is determined that the current is equal to or greater than the threshold current ε, in step S154, the switching elements SW2, SW4, SW6 of the lower arm are all turned off.

  When a negative determination is made in steps S150 and S152, or when the process of step S154 is completed, this series of processes is temporarily terminated.

  According to this embodiment described above, the following effects can be obtained in addition to the effects (8) to (9) of the fifth embodiment.

  (12) When the amount of current flowing through the brushless motor 10 is greater than or equal to a predetermined value by the one-phase and two-phase energization processing of the positioning processing, the energization amount is limited. Thereby, it can avoid that the power consumption of positioning processing becomes large too much. And it can suppress that the torque which arises by the electricity supply operation for positioning becomes excessive, and can shorten the convergence time of a rotation angle.

(Tenth embodiment)
Hereinafter, the tenth embodiment will be described with reference to the drawings, centering on differences from the previous sixth embodiment.

  FIG. 23 shows a procedure of processing relating to the start of the starting processing of the brushless motor 10 according to the present embodiment. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example, triggered by the ignition switch being turned on.

  As shown in the figure, in this series of processing, when the period during which the voltage of the battery 14 is equal to or higher than the specified voltage Vth is equal to or longer than the predetermined period Tv (step S160: YES), the control of the brushless motor 10 in the control device 20 is performed. Various parameters for initialization are initialized (step S162), and processing for starting the brushless motor 10 is performed (step S164). That is, the process shown in FIG. 18 is performed.

  Here, the specified voltage Vth is set to a value obtained by adding a predetermined margin to a voltage necessary for the operation of the control device 20 to be stable. Then, by waiting for the start of the brushless motor 10 until the state in which the voltage of the battery 14 becomes equal to or higher than the specified voltage Vth continues for a predetermined period Tv or longer, as shown in FIG. The motor 10 can be started.

  The initialization process in step S162 is a process performed because the reliability of parameters used in the control device 20 may be reduced because the voltage applied to the control device 20 is once lowered. .

  According to this embodiment described above, the following effects can be obtained in addition to the effects (8) to (9) of the fifth embodiment.

  (13) The brushless motor 10 is on standby until the voltage of the brushless motor 10 becomes equal to or higher than a predetermined specified voltage γ. Thereby, the situation where the rotation state of the brushless motor 10 becomes uncontrollable due to the unstable operation of the control device 20 can be avoided. For this reason, after stopping the rotation of the brushless motor 10, it is possible to avoid a situation where the starting process is performed again.

  (14) The start of the brushless motor 10 is waited until the period in which the voltage of the battery 14 is equal to or higher than the specified voltage γ continues for a predetermined time Tv. Thereby, it is possible to start in a state where the voltage of the battery 14 is stable.

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

  In the ninth embodiment, current limiting may be performed by turning off the switching element of the upper arm. However, in this case, for example, a process of limiting the current is performed depending on whether or not the sum of the current values flowing through the switching elements of the lower arm is equal to or greater than a predetermined value.

  A change in the ninth embodiment with respect to the fifth embodiment may be applied to the sixth to eighth embodiments.

  The changes of the tenth embodiment with respect to the fifth embodiment may be applied to the first to fifth and seventh to ninth embodiments.

  The positioning process is not limited to one in which a current flows from one phase to another two phases by turning on one phase switching element of the upper arm and the other two phase switching elements of the lower arm. For example, a current may be supplied from two phases to another one phase by turning on a two-phase switching element of the upper arm and another one-phase switching element of the lower arm. When the brushless motor 10 having four or more phases is used, for example, the two-phase switching element of the upper arm may be turned on and the two-phase switching element of the lower arm may be turned on. .

  -As a predetermined angle, it is not restricted to what was illustrated by the said embodiment. In this case, it is desirable to set the angle region from the advanced angle side from the angle retarded by “180 °” to the retarded side from the angle advanced by “30 °”. Further, in order to generate a positive torque by the first switching operation for starting the brushless motor 10, it is desirable to set to the retard side. Furthermore, from the viewpoint of shortening the starting time regardless of whether or not there is a current limit, it is desirable that the angle is advanced from the angle delayed by “120 °”.

  In the third embodiment, the elapsed time from the previous zero cross timing to the present is estimated based on the induced voltage and the rotation speed, but the present invention is not limited to this. For example, the elapsed time may be estimated based on the maximum or minimum value of the induced voltage in the previous masking cancellation period and the current induced voltage. That is, in the above embodiment, the rotational speed is used in view of the fact that the amplitude of the induced voltage depends on the rotational speed, but instead, the amplitude can be increased even if the maximum value or the minimum value of the previous induced voltage is used. I can grasp it.

  The method for setting the specified timing is not limited to the method of calculating the required time from the immediately preceding zero cross timing to the specified timing according to the interval of the zero cross timing and correcting this according to the change in the rotational speed. For example, a two-dimensional map that defines the relationship between the rotational speed and acceleration and the required time may be used. Further, for example, the required time t may be calculated by “predetermined angle = Ni × t + (½) × Ai × t × t” from a predetermined angle from the zero cross timing to the specified timing, the rotational speed Ni, and the acceleration Ai. .

  The method for extracting information on the change in the rotation speed from the detection result of the zero cross timing and setting the specified timing based on the information is not limited to those exemplified in the above embodiments and the modifications thereof. For example, at the zero cross timing, the specified timing setting counter value may be “current measurement counter value × (current measurement counter value / previous measurement counter value)”. Also, the specified timing setting counter value may be “current measurement counter value−K × (current measurement counter value−previous measurement counter value)”. That is, any information may be used as long as the above information is extracted by using the detection results of three or more zero cross timings and the specified timing is set based on the information.

  In the fourth embodiment, the current limit value may be changed only when the acceleration is positive and excessive.

  The configuration of the current detection unit 24 is not limited to that illustrated in the above embodiment. For example, a shunt resistor may be provided between each switching element SW1, SW3, SW5 and the positive potential of the battery 14, and a current flowing through them may be detected based on the amount of voltage drop due to the shunt resistor.

  The brushless motor 10 is not limited to an actuator mounted on a fuel pump, and may be a fan actuator that cools a radiator of an in-vehicle internal combustion engine, for example. Furthermore, a data recording device and a playback device mounted in an in-vehicle navigation system, that is, a data recording device and a playback device for a disk medium such as a DVD (Digital Versatile Disc), a CD-ROM (Compact Disc Read Only Memory), and a hard disk are provided. An electric motor may be used. The rotating electrical machine is not limited to a motor, and may be a generator.

  The power source is not limited to the battery 14 and may be, for example, a generator that converts rotational energy of an in-vehicle internal combustion engine into electric energy.

The figure which shows the whole structure of the control apparatus of the brushless motor concerning 1st Embodiment. The time chart which shows the aspect of the switching control concerning the embodiment. The time chart which shows the aspect of the switching control concerning the embodiment. The flowchart which shows the setting aspect of the various counters concerning the embodiment. The flowchart which shows the procedure of the switching process to the ON state of the switching element concerning the embodiment. The figure which shows the shift | offset | difference of the induced voltage of regular time and acceleration time. The figure which shows the experimental result of the detection error of the angle of the rotor at the time of acceleration. The flowchart which shows the procedure of the setting process of the prescription | regulation timing concerning the said embodiment. The time chart which shows the simulation result of the raise aspect of the rotational speed at the time of starting concerning the embodiment. The time chart which shows the simulation result of the raise aspect of the conventional rotational speed at the time of starting. 9 is a flowchart showing a procedure of a specified timing setting process according to the second embodiment. The flowchart which shows the procedure of the estimation process of the zero crossing timing concerning 3rd Embodiment. The flowchart which shows the procedure of the electric current restriction | limiting process concerning 4th Embodiment. The figure which shows the positioning process before the start of the brushless motor concerning 5th Embodiment. The time chart which shows the convergence time of the angle of the rotor by the said positioning process. The figure which shows the relationship between the angle fixed by the positioning process, and starting time. The figure which shows the relationship between the angle fixed by the positioning process, and the production | generation torque at the time of a start start. The flowchart which shows the procedure of the positioning process concerning the said embodiment. The flowchart which shows the procedure of the positioning process concerning 6th Embodiment. The flowchart which shows the procedure of the positioning process concerning 7th Embodiment. The flowchart which shows the procedure of the positioning process concerning 8th Embodiment. The flowchart which shows the procedure of the restriction | limiting process of the energizing amount at the time of the positioning process concerning 9th Embodiment. The flowchart which shows the process sequence of the start start of the brushless motor concerning 10th Embodiment. The time chart which shows transition of the voltage of the battery at the time of the start concerning the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Brushless motor, 12 ... Inverter, 20 ... Control apparatus, 22 ... Driver, 24 ... Current detection part, 26 ... Switching control part, SW1-SW6 ... Switching element, D1-D6 ... Diode.

Claims (15)

When controlling the rotating electrical machine by operating the switching element of the power conversion circuit, the time required from the zero cross timing at which the induced voltage of the rotating electrical machine becomes the reference voltage to the specified timing as the reference for the operation of the switching element is the zero crossing. In a control device for a rotating electrical machine that calculates based on a timing interval,
Extraction means for extracting information on a change in rotational speed of the rotating electrical machine from the detection result of the zero cross timing;
In order to electric angle change amount of the rotary electric machine and the same during the period from the zero-cross timing before and after the change of the rotational speed to the prescribed timing, Bei example and setting means for setting said prescribed timing based on the information,
The extraction means is means for calculating the acceleration of the rotating electrical machine based on a plurality of values for the interval of the zero cross timing.
The control device for a rotating electrical machine, wherein the setting means is a means for setting the specified timing using the acceleration as the information when the rotating electrical machine is started.   2. The control device for a rotating electrical machine according to claim 1, wherein the setting of the specified timing based on the information is performed by advancing the specified timing as the amount of change on the increase side of the rotation speed increases.   The setting means includes a required time calculating means for calculating a required time from the zero cross timing immediately before the specified timing to the specified timing from the interval of the zero cross timing, and a correcting means for correcting the required time based on the information. The control apparatus for a rotating electrical machine according to claim 1, comprising: The power conversion circuit includes rectifying means connected in parallel to each switching element,
Comparing means for comparing the magnitude relationship between the terminal voltage of the rotating electrical machine and a reference voltage, and invalidating means for invalidating the comparison by the comparing means over a predetermined period from the zero cross timing,
The zero cross timing is detected as an inversion timing of the comparison result of the comparison means,
The required time is a required time from the zero cross timing immediately before the specified timing,
When the invalidation means cancels the invalidation, when the previous zero cross timing has already passed, the estimation means further includes an estimation means for estimating an elapsed time from the previous zero cross timing to the present based on the induced voltage. The control device for a rotating electrical machine according to any one of claims 1 to 3 . Acceleration calculation means for calculating the acceleration of the rotating electrical machine based on a plurality of values for the interval of the zero cross timing;
A motor controller according to any one of claims 1 to 4, further comprising a limiting means for limiting the current amount of the rotary electric machine according to the acceleration the calculated. The rotating electrical machine is a multiphase rotating electrical machine;
Prior to starting the rotating electrical machine, further comprising positioning means for fixing the rotational angle of the rotating electrical machine to a predetermined angle by flowing a current from a part of the phase of the rotating electrical machine to another part of the phase,
A motor controller according to any one of claims 1 to 5, characterized in that said at least one of a portion of phase or said another portion of the phase is composed of a plurality of phases. In a control device for a rotating electrical machine that controls the output of the rotating electrical machine while setting a prescribed timing that is a reference for operation of a switching element of a power conversion circuit based on an induced voltage of a multiphase rotating electrical machine,
Prior to starting the rotating electrical machine, further comprising positioning means for fixing the rotational angle of the rotating electrical machine to a predetermined angle by flowing a current from a part of the phase of the rotating electrical machine to another part of the phase,
At least one of said one part phase or said another one part phase consists of several phases, The control apparatus of the rotary electric machine characterized by the above-mentioned. The rotating electrical machine control device according to claim 6 or 7, wherein the rotating electrical machine is a three-phase rotating electrical machine. The positioning means, after the process of flowing a current from one phase of the rotating electrical machine to another part of the phase, either the positive side or the negative side of the power source of the rotating electrical machine and all phases of the rotating electrical machine The control device for a rotating electrical machine according to any one of claims 6 to 8 , further comprising short-circuiting means for short-circuiting all phases of the rotating electrical machine by being in a conductive state. The positioning means performs a process of flowing a current from a part of the rotating electrical machine to another part of the phase several times while changing the part of the phase and the part of the other part, The rotating electrical machine control device according to any one of claims 6 to 9 , wherein a rotational angle of the rotating electrical machine is fixed to the predetermined angle. The positioning means, after passing a current from the partial phase to the another partial phase, before changing the partial phase and the another partial phase, The rotating electrical machine according to claim 10 , further comprising means for short-circuiting all phases of the rotating electrical machine by bringing either the positive electrode side or the negative electrode side into conduction with all phases of the rotating electrical machine. Control device. 12. The apparatus according to claim 6 , further comprising a limiting unit configured to limit an energization amount of the rotating electrical machine when an amount of current flowing through the rotating electrical machine exceeds a predetermined value by an energization operation by the positioning unit. The control apparatus of the rotary electric machine described. The positioning means determines the predetermined angle from an angle delayed by “180 °” with respect to the convergence value of the rotation angle of the rotating electrical machine when the state of the first switching operation accompanying the start of the rotating electrical machine is continued. The rotating electrical machine according to any one of claims 6 to 12 , wherein the rotating electrical machine is set in an angle region from the advance side to the retard side from the angle advanced by "30 °" with respect to the convergence value. Control device. The rotating electrical machine is mounted on an in-vehicle engine system,
The rotating electrical machine according to any one of claims 1 to 13 , further comprising standby means for waiting for starting of the rotating electrical machine until a voltage of a power source of the rotating electrical machine becomes equal to or higher than a predetermined specified voltage. Control device. A motor controller according to any one of claims 1 to 14, wherein the rotary electric machine is an actuator of the fuel pump.

Images