JP2008193811A - Controller for rotating machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein it is difficult to discriminate between an abnormal state, where it is difficult to control a rotational state and a rotational ripple state caused by load ripple, etc. , based on the zero-cross timing, when induced voltage is based on the timing that is detected on the terminal voltages vu, vv and vw of a brushless motor 10 and the reference voltage vref that cross zero. <P>SOLUTION: When the zero-cross timing appears continuously on the side of phase lead l or phase lag by more than a permitted period and the detection of zero-cross timing, based on the agreement between the terminal voltages vu, vv and vw and the reference voltage vref is permitted, the controller decides it as being an uncontrollable step-out state. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is directed to a power conversion circuit in which each of a positive electrode and a negative electrode of a power source and a rotating machine are connected by a switching element and a rectifier is connected in parallel to each of the switching elements. The present invention relates to a control device for a rotating machine that sets a specified timing as a reference for operating the switching element by detecting a timing at which the electrical angle of the rotating machine becomes a predetermined electrical angle based on an induced voltage.

  As this type of control device, for example, as can be seen in Patent Document 1 below, the induced voltage of each phase is determined according to the electrical angle of the three-phase motor, and is grasped from the terminal voltage of the three-phase motor. Some have been proposed that detect the timing at which a predetermined electrical angle of the motor is reached based on the induced voltage.

Here, immediately after the switching element of any phase is turned off, a current flows through a diode (rectifying means) connected in parallel with the switching element. At this time, when the terminal voltage is largely separated from the induced voltage, there is a possibility that it is erroneously detected that the timing becomes a predetermined electrical angle. On the other hand, in Patent Document 1, the current is passed through the diode. In order to avoid erroneous detection due to flow, a permission period for permitting detection of the timing at which the predetermined electrical angle is reached is limited.
Japanese Patent Laid-Open No. 11-18478

  By the way, an abnormality in which the detected value of the rotational speed of the motor shifts to an excessively large value and an abnormality that shifts to an excessively small value and is fixed may occur. In these cases, it is difficult to control the rotational state of the motor as desired. In addition, when shifting to an excessively large value or when shifting to an excessively small value, the timing at which the predetermined electrical angle is reached is not within the permitted period.

  However, for example, when the rotational speed of the motor suddenly fluctuates due to a sudden fluctuation in the power supply voltage or a sudden change in the motor load, the timing at which the predetermined electrical angle is reached is temporarily permitted. There are times when it does not enter. For this reason, when there is an abnormality in the rotation state when the timing of the predetermined electrical angle does not enter the permission period, a state where the rotation state is difficult to control as desired (step-out state), There is a risk that both the temporary rotational fluctuation state due to the load fluctuation and the like are determined to be abnormal.

  Therefore, inconveniences such as it becomes difficult to continue the control of the rotating machine only by the load fluctuation.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a control device for a rotating machine that can more appropriately grasp the rotation state of the rotating machine based on the induced voltage of the rotating machine. There is.

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

  According to a first aspect of the present invention, there is provided permission period setting means for setting a permission period for permitting detection of the predetermined electrical angle based on a detected value of a terminal voltage of the rotating machine, and the predetermined electrical angle is set by the permission period. And determining means for determining that there is an abnormality in the rotational state of the rotating machine when the number of times of continuous appearing on either the advance side or the retard side is equal to or greater than a threshold value.

  There may be an abnormality in which the detected value of the rotational speed of the rotating machine shifts to an excessively large value and an abnormality that shifts to an excessively small value and is fixed. In these cases, it is difficult to control the rotation state of the rotating machine as desired. Here, when shifting to an excessively large value or when shifting to an excessively small value, the timing at which the predetermined electrical angle is reached is not within the permitted period. However, even when a rotational fluctuation occurs in the rotating machine due to a temporary load fluctuation or the like, the timing at which the predetermined electrical angle is reached may not temporarily fall within the permitted period. For this reason, when there is an abnormality in the rotation state when the timing of the predetermined electrical angle does not enter the permission period, a state where the rotation state is difficult to control as desired (step-out state), There is a risk that both the temporary rotational fluctuation state due to the load fluctuation and the like are determined to be abnormal.

  However, in the step-out state, the state where the timing at which the predetermined electrical angle is reached is shifted to the advance side or the retard side of the permission period continues, but when the rotational fluctuation occurs due to a load fluctuation or the like, the deviation occurs. The condition does not tend to continue that much. In the above invention, paying attention to this point, it is determined that there is an abnormality when the number of times that the predetermined electrical angle continuously appears on either the advance side or the retard side of the permission period is equal to or greater than the threshold value. Thereby, when a rotational fluctuation temporarily occurs due to a load fluctuation or the like, it is possible to avoid judging this as abnormal.

  According to a second aspect of the present invention, in the first aspect of the invention, the timing at which the predetermined electrical angle is reached is a zero cross timing at which an induced voltage of the rotating machine becomes a reference voltage, and the zero cross timing is It is detected based on the magnitude relationship between the detected value of the terminal voltage of the rotating machine and the reference voltage.

  The timing at which the induced voltage becomes the reference voltage occurs at a predetermined electrical angle cycle. For this reason, in the said invention, the timing which becomes a predetermined electrical angle can be defined appropriately.

  The invention according to claim 3 further comprises means for judging whether or not the zero cross timing has appeared on the advance side with respect to the permission period in the invention according to claim 2, and further on the advance side with respect to the permission period. When it is determined that it has appeared, the specified timing is set assuming that the start of the permission period is the zero cross timing.

  In the above invention, when it is determined that the zero cross timing has appeared on the advance side of the permission period, the start of the permission period is assumed to be the zero cross timing. For this reason, even when there is an error in the determination, it is possible to prevent the specified timing from being set to an inappropriate timing.

  According to a fourth aspect of the present invention, in the second aspect of the invention, the means for determining whether the zero-cross timing has appeared on the advance side with respect to the permission period, and the advance side with respect to the permission period, Means for setting the most advanced angle timing that can be adopted as the zero cross timing, and when it is determined that the zero cross timing has appeared on the advanced angle side from the permission period, the zero cross timing is determined from the most advanced angle timing. The prescribed timing is set on the assumption that the timing is until the start of the permission period.

  In the above invention, when it is determined that the zero cross timing appears on the advance side of the permission period, the timing between the most advanced angle timing and the start of the permission period is assumed to be the zero cross timing. For this reason, even when there is an error in the determination, it is possible to prevent the specified timing from being set to an inappropriate timing. In addition, the presence or absence of an abnormality in the rotating state of the rotating machine can be appropriately detected based on the fact that it is out of the permission period.

  The invention according to claim 5 is the invention according to any one of claims 2 to 4, further comprising means for determining whether or not the zero cross timing appears on the retard side of the permission period, and the permission period. When it is determined that the delay time appears on the more retarded side, the predetermined timing is set assuming that the end of the permission period is the zero cross timing.

  In the above invention, when it is determined that the zero cross timing appears on the retarded side of the permission period, the end of the permission period is assumed to be the zero cross timing. For this reason, even when there is an error in the determination, it is possible to prevent the specified timing from being set to an inappropriate timing.

  According to a sixth aspect of the invention, there is provided the comparator according to any one of the second to fifth aspects, further comprising comparison means for outputting a binary signal corresponding to a magnitude relationship between the terminal voltage and the reference voltage. The means determines whether or not the zero cross timing appears on the more advanced side than the permission period based on the value of the binary signal at the start of the permission period, and changes the logical value within the permission period. It is characterized in that it is determined whether or not the zero cross timing appears on the retard side of the permission period based on presence or absence.

  The logical value of the comparison means at the zero cross timing is uniquely determined from the previous logical value. In the above invention, paying attention to this point, it is possible to determine whether or not the zero cross timing appears on the advance side of the permission period based on the value of the binary signal at the start of the permission period. On the other hand, if the zero cross timing does not occur within the permission period, the change in the logical value of the binary signal due to the zero cross timing does not occur within the permission period. In the above invention, paying attention to this point, it is possible to appropriately determine whether or not the zero cross timing appears on the retard side of the permission period based on the presence or absence of a change in the logical value within the permission period.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the permission period setting means is grasped from a detected value of a time interval between adjacent timings that becomes the predetermined electrical angle. The apparatus further comprises means for setting a required time from the predetermined electrical angle to the permission period based on a rotation speed of the rotating machine and a change in the rotating speed of the rotating machine.

  The time interval between adjacent timings at a predetermined electrical angle has a correlation with the rotational speed of the rotating machine. The required time from the predetermined electrical angle to the permission period can be determined by the rotational speed of the rotating machine if the rotating speed of the rotating machine is constant. However, when the rotational speed of the rotating machine changes, an error occurs if the required time from a predetermined electrical angle is set based on the rotational speed. In this regard, in the above invention, the permission period can be set with high accuracy by setting the required time in accordance with the change in the rotation speed.

  The invention according to claim 8 is the invention according to claim 7, wherein the change in the rotational speed is grasped by a change in a detected value of the voltage of the power source.

  When the voltage of the power supply changes, the rotational speed of the rotating machine can fluctuate. In this regard, in the above invention, the change in the rotation speed can be appropriately grasped by using the change in the voltage of the power source as a parameter indicating the change in the rotation speed.

  Note that when the switching timing of the switching element operation is controlled so as to correspond one-to-one with the timing at which the predetermined electrical angle is reached, the change in the rotational speed has a particularly strong correlation with the change in the voltage of the power source. Have. Therefore, in such a case, the application of the above invention is particularly effective.

  According to a ninth aspect of the invention, in the seventh aspect of the invention, there is provided extraction means for extracting information relating to the change in the rotation speed based on the detection result of the timing at which the predetermined electrical angle is reached, and the change in the rotation speed. Is characterized by the extracted information.

  Information regarding the rotation state of the rotating machine is included in the timing of the predetermined electrical angle. In particular, the information regarding the change in the rotational speed is included in the three or more detection values for the timing at which the predetermined electrical angle is reached. In the above-mentioned invention, paying attention to this point, it is possible to acquire information relating to a change in the rotational speed.

  The invention according to claim 10 includes permission period setting means for setting a permission period for permitting detection of the predetermined electrical angle based on a detected value of the terminal voltage of the rotating machine, wherein the permission period setting means is the predetermined period. From the predetermined electrical angle to the permission period based on the rotational speed of the rotating machine, which is grasped from the detected value of the time interval between adjacent timings that become the electrical angle of A means for setting the required time is provided.

  The time interval between adjacent timings at a predetermined electrical angle has a correlation with the rotational speed of the rotating machine. The required time from the predetermined electrical angle to the permission period can be determined by the rotational speed of the rotating machine if the rotating speed of the rotating machine is constant. However, when the rotational speed of the rotating machine changes, an error occurs if the required time from a predetermined electrical angle is set based on the rotational speed. In this regard, in the above invention, the permission period can be set with high accuracy by setting the required time in accordance with the change in the rotation speed.

  The invention described in claim 11 is characterized in that, in the invention described in claim 10, the change in the rotational speed is grasped by the change in the detected value of the voltage of the power source.

  When the voltage of the power supply changes, the rotational speed of the rotating machine can fluctuate. In this regard, in the above invention, the change in the rotation speed can be appropriately grasped by using the change in the voltage of the power source as a parameter indicating the change in the rotation speed.

  Note that when the switching timing of the switching element operation is controlled so as to correspond one-to-one with the timing at which the predetermined electrical angle is reached, the change in the rotational speed has a particularly strong correlation with the change in the voltage of the power source. Have. Therefore, in such a case, the application of the above invention is particularly effective.

  According to a twelfth aspect of the present invention, in the tenth aspect of the invention, there is provided extraction means for extracting information relating to the change in the rotation speed based on the detection result of the timing at which the predetermined electrical angle is reached, and the change in the rotation speed. Is characterized by the extracted information.

  Information regarding the rotation state of the rotating machine is included in the timing of the predetermined electrical angle. In particular, the information regarding the change in the rotational speed is included in the three or more detection values for the timing at which the predetermined electrical angle is reached. In the above-mentioned invention, paying attention to this point, it is possible to acquire information relating to a change in the rotational speed.

  The invention according to claim 13 is the invention according to any one of claims 10 to 12, wherein the timing of the predetermined electrical angle is a zero cross timing at which the induced voltage of the rotating machine becomes a reference voltage, and The zero cross timing is detected based on a magnitude relationship between a detected value of a terminal voltage of the rotating machine and the reference voltage.

  The timing at which the induced voltage becomes the reference voltage occurs at a predetermined electrical angle cycle. For this reason, in the said invention, the timing which becomes a predetermined electrical angle can be defined appropriately.

  The invention according to any one of claims 1 to 13 is an actuator of a fuel pump in which the rotating machine supplies fuel to an internal combustion engine mounted on a motorcycle, as in the invention according to claim 14. You may make it feature.

(First embodiment)
Hereinafter, a first embodiment in which a control device for a rotating machine according to the present invention is applied to a control device for 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 arm) and the switching elements SW3 and SW4 (V-phase arm) so that each of the three phases and the positive electrode side or the negative electrode side of the battery 14 are electrically connected. It is configured to include a parallel connection body with the elements SW5 and SW6 (W-phase arm). 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.

  The switching elements SW1, SW3, SW5 on the upper side of each arm are configured by P-channel MOS transistors, and the switching elements SW2, SW4, SW6 on the lower side of each arm are configured by 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 voltage detection unit 24, and a switching control unit 26. Here, the voltage detection unit 24 detects the voltage VB of the battery 14.

  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 at which the induced voltage becomes the virtual 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 ( Zero cross timing) is detected. 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 (energization amount) flowing through the brushless motor 10 is limited, PWM control is performed within this period instead of setting the period during which the switching elements SW1 to SW6 are turned on as "120 °". .

  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.

  FIG. 2 shows a switching control mode in a normal state. Specifically, FIG. 2A shows the transition of the terminal voltages vu, vv, and vw, FIG. 2B shows the transition of the comparison signals Uc, Vc, and Wc, and FIG. 2C shows the zero cross detection. FIG. 2D shows changes in the values of various counters, and FIG. 2E shows changes in the operation signals of the switching elements SW1 to SW6. The operation signals shown in FIG. 2 (e) are the operation signals U +, V +, W + of the upper switching elements SW1, SW3, SW5 of each arm and the operation signals U− of the lower switching elements SW2, SW4, SW6. , V-, W-. Here, since the switching elements SW1, SW3, and SW5 on the upper side of each arm are P-channel transistors, the period during which these operation signals U +, V +, and W + are in the logic “L” period is the on-period.

  A thick line in FIG. 2D indicates the value of the measurement counter that measures the interval between the 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, a thin line in FIG. 2D shows the 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, for example, when 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. Considering that the interval between adjacent zero-cross timings is “60 °”, the timing at which the specified timing setting counter becomes “0” is set to a timing delayed by “30 °” from the zero-cross timing by such setting. It is thought that you can.

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

  Further, in FIG. 2D, the one-dot chain line indicates the value of the permission period setting counter that determines the permission period. When the permission start counter reaches zero, the permission period setting counter decrements the value before the previous initialization of the measurement counter as an initial value, and sets the period until it becomes zero as the permission period . For example, if the permission period is a period of “30 °”, the decrement speed may be set to twice the increment speed of the measurement counter.

  The comparison signals Uc, Vc, Wc are valid during the period when the permission period setting counter is zero or more, and the comparison signals Uc, Vc, Wc are inverted during this period, so that the zero-cross detection signal of the corresponding phase is inverted. . Then, the decrement of the specified timing setting counter is started from the zero cross timing at which the zero cross detection signal is inverted, and the operation of the switching elements SW1 to SW6 is switched when the value becomes zero.

  Hereinafter, the processing procedure of the switching control according to the present embodiment will be further described with reference to FIGS. 3 and 4. FIG. 3 shows a procedure for setting the counter values of the four 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 permission period setting counter is zero or more. If it is determined that the value is greater than or equal to zero, in step S12, it is determined whether any of the comparison signals Uc, Vc, and Wc is inverted. This process detects zero cross timing. When it is determined in step S12 that one of the signals has been reversed, in step S14, the current measurement counter value is set as the measurement counter maximum value. In the subsequent step S16, the values of the specified timing setting counter and the permission period setting counter are set to the measurement counter maximum values. In step S18, the measurement counter is initialized.

  On the other hand, when a negative determination is made in steps S10 and S12, in step S20, the measurement counter is incremented, and the permission start counter, the permission period setting counter, and the specified timing setting counter are decremented. In a succeeding step S22, it is determined whether or not the permission start counter is zero. This process is for determining whether or not it is the start of the permission period. When it is determined that the permission start counter is zero, in step S24, the permission period setting counter is set to the measurement counter maximum value. Thereafter, detection of zero cross timing based on the comparison signals Uc, Vc, and Wc is permitted until the value of the permission period setting counter becomes zero.

  When a negative determination is made in step S22 or when the processes in steps S18 and S24 are completed, this series of processes is temporarily terminated.

  FIG. 4 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. When it is determined that the specified timing setting counter has become zero, the operation states of the switching elements SW1 to SW6 are switched in step S32. Here, when the switching elements SW1 and SW4 are on before switching, the switching elements SW1 and SW6 are switched to turn on. If the switching elements SW1 and SW6 are in the on state before switching, the switching elements SW3 and SW6 are switched to the on state. If the switching elements SW3 and SW6 are in the on state before switching, the switching elements SW2 and SW3 are switched to the on state. If the switching elements SW2 and SW3 are in the on state before switching, the switching elements SW2 and SW5 are switched to the on state. If the switching elements SW2 and SW5 are in the on state before switching, the switching elements SW4 and SW5 are switched to the on state. If the switching elements SW4 and SW5 are in the on state before switching, the switching elements SW1 and SW4 are switched to the on state.

  As described above, in this embodiment, the switching control by the 120 ° energization method is performed by associating the switching timing of the switching elements SW1 to SW6 with the zero cross timing in a one-to-one relationship.

  By the way, in the vehicle, the voltage of the battery 14 is likely to fluctuate. When the voltage of the battery 14 fluctuates, the rotation speed of the brushless motor 10 changes. At this time, since the time interval between the adjacent zero cross timings (measurement counter maximum value) cannot accurately represent the rotation speed in the vicinity of the current zero cross timing, depending on the time interval, the permission period may be set as desired. It cannot be set in the electrical angle range. For this reason, for example, when the brushless motor 10 is accelerated, the zero cross timing may appear on the advance side with respect to the permission period set in the above-described manner. Further, for example, when the brushless motor 10 is decelerated, the zero cross timing may appear on the retard side of the permission period set in the above manner.

  Therefore, in the present embodiment, the setting of the permission period is corrected according to a change in the rotation speed of the brushless motor 10. Specifically, in view of the fact that the rotation speed changes due to the change in the voltage VB of the battery 14, the setting of the permission period is corrected according to the change in the voltage of the battery 14. This will be further described below.

  FIG. 5 shows a procedure of correction processing for setting the permission period 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 S40, the voltage VB of the battery 14 is acquired. In a succeeding step S42, it is determined whether or not the change amount ΔVB of the voltage VB of the battery 14 is equal to or larger than the first threshold value α. This process determines whether or not the brushless motor 10 is in an accelerated state, so that it is assumed that the zero cross timing appears on the advance side of the permission period determined by the rotational speed. The threshold value α is set based on the minimum value for the above situation. When it is determined that the change amount ΔVB is equal to or greater than the threshold value α, the count speeds of the permission start counter and the permission period setting counter are increased in step S44. Specifically, as shown in the lower part of FIG. 5, the count speed is increased as the change amount ΔVB is larger. Here, a correction coefficient may be determined for each discrete value of the change amount ΔVB, and the count speed may be changed stepwise. Alternatively, it may be continuously changed according to the change amount ΔVB. This process is for setting the permission period to be substantially the same electrical angle region as when the rotation speed is constant under the situation where the rotation speed of the brushless motor 10 increases.

  On the other hand, when the change amount ΔVB is less than the threshold value α, it is determined in step S46 whether or not the change amount ΔVB is less than or equal to the second threshold value β. This process is to determine whether or not the brushless motor 10 is in a decelerating state, so that it is assumed that the zero cross timing appears on the retard side of the permission period determined by the rotational speed. The threshold value β is set based on the maximum value in the above situation. When it is determined that the change amount ΔVB is equal to or less than the threshold value β, the count speeds of the permission start counter and the permission period setting counter are decreased in step S48. Specifically, as shown in the lower part of FIG. 5, the count speed is decreased as the change amount ΔVB is smaller (negative and its absolute value is larger). This process is for allowing the permission period to be in substantially the same electrical angle region as when the rotational speed is constant under a situation where the rotational speed of the brushless motor 10 is reduced.

  When it is determined in step S46 that the change amount ΔVB is larger than the threshold value β, or when the processes in steps S44 and S48 are completed, this series of processes is temporarily ended. According to the above processing, even when the rotational speed of the brushless motor 10 changes due to the change in the voltage VB of the battery 14, the zero cross timing can be detected appropriately.

  By the way, when the rotational speed of the brushless motor 10 based on the detected value of the zero cross timing becomes excessively high or excessively low, it is difficult to appropriately control the rotational state of the brushless motor 10 (step-out state). ) May occur. At this time, it is desirable to restart the brushless motor 10. Here, before falling into such a state, since the rotational speed of the brushless motor 10 continues to increase or decrease, a phenomenon in which the zero cross timing deviates from the permitted period tends to occur continuously a plurality of times. Therefore, in the present embodiment, when the number of times that the zero cross timing appears continuously on either the advance side or the retard side of the permission period is equal to or greater than the threshold value, it is determined that there is an abnormality in the rotational state of the brushless motor 10 and the brushless motor. 10 is restarted. This will be described in detail below with reference to FIGS.

  FIG. 6 is a processing procedure at the time of abnormality in which the zero cross timing appears on the advance side of the permission period. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processing, first, in step S50, it is determined whether or not the permission start counter is zero. This process is to determine whether or not it is the start of the permission period. When it is determined that the permission start counter is zero, it is determined in step S52 whether or not the corresponding logical value is normal among the comparison signals Uc, Vc, and Wc. This process determines whether or not the zero cross timing appears on the advance side of the permission period.

  As shown in FIG. 2, the zero-cross timing occurs every “60 °”, and it is “360 °” that the induced voltage of which phase crosses the reference voltage vref in the rising process or the falling process. Has periodicity of period. For this reason, the current zero-cross timing occurs in which phase depending on whether the previous zero-cross timing occurred in which phase and the induced voltage in that phase was in the rising or falling process, and the induced voltage in that phase It is possible to specify whether is a rising process or a falling process. That is, for example, in FIG. 2, when the zero-cross timing occurs when the terminal voltage vv of the V-phase crosses the reference voltage vref in the decreasing process, the next zero-crossing timing is the U-phase and the zero-crossing is performed in the increasing process of the terminal voltage vu. It can be determined that timing occurs. For this reason, it is considered that the U-phase comparison signal Uc is inverted from logic “L” to logic “H” in the permission period. On the other hand, if the U-phase comparison signal Uc is already at logic “H” when the permission start counter becomes zero, it can be determined that the zero cross timing has occurred on the advance side of the permission period.

  When it is determined that the logical value of the comparison signal of the phase that is assumed to be the zero cross timing in the permission period is abnormal, the process proceeds to step S54. In step S54, it is determined that the zero cross timing is excessively advanced. Then, the measurement counter value is substituted into the permission start counter and the specified timing setting counter. As a result, the prescribed timing and the like are set assuming that the timing when the permission start counter becomes zero is the zero cross timing. This process is for avoiding the setting of the specified timing and the like being excessively deviated from the normal timing even when an erroneous determination is made in the process of step S52. In the subsequent step S56, the measurement counter is initialized.

  Further, in step S58, it is determined whether or not the previous zero cross timing has appeared on the advance side of the permission period. If the previous zero cross timing also appears on the advance side of the permission period, the over-advance counter is incremented in step S60. Here, the over-advance angle counter counts the number of times that the zero cross timing appears continuously on the advance side of the permission period. In a succeeding step S62, it is determined whether or not the over-advance counter value has reached the threshold value MAX. This process determines whether or not the rotation state of the brushless motor 10 is abnormal and it is difficult to control the rotation state. This threshold value MAX is set to a value larger than the number of times that the zero cross timing is assumed to be on the advance side of the permission period when the brushless motor 10 is started. When it is determined that the over-advance angle counter is the threshold value MAX, in step S64, the brushless motor 10 is restarted (returned) and the over-advance angle counter is initialized.

  On the other hand, when a negative determination is made in step S58, the over-advance angle counter is initialized in step S66. In this process, the over-advance counter value is accumulated when the zero cross timing is advanced from the permission period due to the start of the brushless motor 10, the influence of noise, load fluctuation, etc. This is to avoid the start process being performed. When a negative determination is made in steps S50 and S52 or when the processes in steps S64 and S66 are completed, the series of processes is temporarily terminated.

  FIG. 7 is a processing procedure at the time of abnormality in which the zero cross timing appears on the retard side of the permission period. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processes, first, in step S70, it is determined whether or not the permission period setting counter is zero. This process is to determine whether or not the end of the permission period. When it is determined that the permission period setting counter is zero, in step S72, it is determined whether an affirmative determination is made in step S52 in FIG. 6 and the zero cross timing has already been detected. This process determines whether or not the zero cross timing appears on the retard side of the permission period. That is, when the zero cross timing does not appear on the advance side of the permission period and does not appear in the permission period, it appears that it appears on the retard side.

  When a negative determination is made in step S72, the same processes as in steps S54 to S66 in FIG. 6 are performed in the processes in steps S74 to S86.

  As described above, in this embodiment, the step-out state is determined based on the fact that the zero-cross timing appears continuously on the advance side or the retard side with respect to the permission period. For this reason, a state in which the zero cross timing accidentally deviates from the permission period due to the influence of noise or the like can be identified as a step-out state. Furthermore, since the permission period is set to be a predetermined electrical angle regardless of the fluctuation of the voltage of the battery 14, it is possible to avoid the determination of the step-out state due to the fluctuation of the voltage of the battery 14. .

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

  (1) When the number of times the zero cross timing appears continuously on either the advance side or the retard side of the permission period is equal to or greater than the threshold value MAX, it is determined that the brushless motor 10 is abnormal. Thereby, when a rotational fluctuation temporarily occurs due to a load fluctuation or the like, it is possible to avoid judging this as abnormal.

  (2) When it is determined that the zero cross timing appears on the advance side of the permission period, the specified timing is set assuming that the start of the permission period is the zero cross timing. As a result, even when there is an error in the determination, it is possible to avoid the prescribed timing being set at an inappropriate timing.

  (3) When it is determined that the zero cross timing appears on the retard side of the permission period, the specified timing is set assuming that the end of the permission period is the zero cross timing. As a result, even when there is an error in the determination, it is possible to avoid the prescribed timing being set at an inappropriate timing.

  (4) Based on the value of the comparison signal at the start of the permission period, it is determined whether the zero cross timing has appeared on the advance side of the permission period, and the zero cross timing is determined based on whether the comparison signal has changed within the permission period. It was determined whether or not it appears on the retard side of the permission period. Thereby, these determinations can be made appropriately.

  (5) The setting of the permission period based on the permission start counter and the permission period setting counter is corrected according to the change in the rotation speed of the brushless motor 10. Thereby, regardless of the change in the rotation speed, the permission period can be set to a desired electrical angle region with high accuracy, and the robustness of the control of the rotation state of the brushless motor 10 can be improved.

  (6) The change in the rotational speed was grasped by the change amount ΔVB of the voltage VB of the battery 14. Thereby, the change of rotation speed can be grasped appropriately. In particular, by detecting the rotation speed based on the voltage VB of the battery 14, the setting of the permission period is not corrected when the rotation state becomes abnormal regardless of the fluctuation of the voltage VB of the battery 14. For this reason, the setting of the permission period based on the time interval between the zero cross timings can be corrected only when the voltage VB of the battery 14 varies.

(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 detected based on the detected value of the zero cross timing, and the setting of the permission period is corrected based on the acceleration. FIG. 8 shows the procedure of correction processing for setting the permission period. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processes, first, in step S90, the acceleration A of the brushless motor 10 is calculated based on the previous measurement counter maximum value and the current measurement counter maximum value. Here, since the measurement counter maximum value measures the time interval between the zero cross timings, it has a correlation with the local rotational speed between the zero cross timings. For this reason, the previous measurement counter maximum value and the current measurement counter maximum value are values at two points in time that are different in time with respect to the local rotation speed. Therefore, the acceleration A can be calculated from these.

  In a succeeding step S92, it is determined whether or not the acceleration A is not less than a threshold value Amax. This process determines whether or not the zero cross timing is on the advance side of the permission period determined by the rotation speed due to the brushless motor 10 being in an acceleration state. Then, when it is determined that the value is equal to or greater than the threshold value Amax, in step S94, processing similar to that in step S44 of FIG. 5 is performed. That is, as shown in the lower part of FIG. 8, as the acceleration A increases, the count speeds of the permission start counter and the permission period setting counter are increased.

  On the other hand, when a negative determination is made in step S92, it is determined in step S96 whether or not the acceleration A is equal to or less than a threshold value Amin. This process determines whether or not the zero cross timing is on the retard side of the permission period determined by the rotation speed due to the brushless motor 10 being in a deceleration state. If it is determined that the value is equal to or less than the threshold value Amin, in step S98, the same process as in step S48 in FIG. 5 is performed. That is, as shown in the lower part of FIG. 8, as the acceleration A is smaller (negative and its absolute value is larger), the count speed of the permission start counter and the permission period setting counter is decreased.

  When a negative determination is made in step S96 or when the processes in steps S94 and S98 are completed, this series of processes is temporarily ended.

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

  (7) Based on the detection result of the zero cross timing, information on the change in the rotational speed of the brushless motor 10 was extracted. Thereby, the change of rotation speed can be grasped appropriately.

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

  In the first embodiment, when the zero cross timing is on the more advanced side than the permission period, the specified timing is set assuming that the start of the permission period is the zero cross timing. However, in this case, when the zero cross timing is continuously advanced from the permission period, the specified timing continues to be delayed from an appropriate timing, and the efficiency of the output control of the brushless motor 10 is reduced. Therefore, in the present embodiment, the most advanced angle timing that can be adopted on the assumption that the zero cross timing is adopted is set on the advance side from the start of the permission timing, and the zero cross timing is on the more advanced side than the permission period. Sometimes, the zero cross timing is set to a timing between the most advanced angle timing and the start of the permission period (including the most advanced angle timing and the start time) and the difference between the zero cross timing and the zero timing is minimized.

  Here, as shown in FIG. 9, the most advanced angle timing is a timing at which the maximum advanced angle counter for starting decrement becomes “0” with the measurement counter value at the zero cross timing as an initial value. By making the decrement speed of this maximum advance angle counter faster than the decrement speed of the permission start counter, the most advanced angle timing, which is the timing when the maximum advance angle counter becomes zero, is set to the advance angle side from the start of the permission period. can do. The most advanced angle timing is determined in advance as a timing at which a predetermined electrical angle from the zero cross timing elapses according to the specifications of the brushless motor 10 or the like.

  FIG. 10 shows a processing procedure at the time of abnormality in which the zero cross timing according to the present embodiment appears on the advance side of the permission period. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example. In FIG. 10, the same steps as those shown in FIG. 6 are given the same step numbers for the sake of convenience.

  In this series of processes, when a negative determination is made in step S52, that is, when it is determined that the zero cross timing has appeared on the advance side of the permission period, the process proceeds to step S100. In step S100, it is determined whether or not the inversion timing of the corresponding one of the comparison signals Uc, Vc, and Wc is on the more advanced side (including the most advanced angle timing) than the most advanced angle timing. This processing may be performed depending on whether the logical value of the corresponding one of the comparison signals Uc, Vc, Wc at the time when the maximum advance counter becomes “0” is abnormal, for example. And when it is judged that it is an advance angle side from the most advance angle timing, in Step S102, in addition to the process of determining the over advance angle of the zero cross timing and the process of setting the permission start counter value as the measurement counter value, A process of setting the specified timing is performed assuming that the most advanced timing is zero-cross timing. That is, based on the period from the previous zero cross timing to the currently assumed zero cross timing, the specified timing setting counter value is set so as to be a value corresponding to the required time from the current time to the specified timing.

  On the other hand, if it is determined in step S100 that the timing is behind the most advanced angle timing, in step S104, an over-advance angle determination process at zero cross timing or a process using the permission start counter value as a measurement counter value. In addition, a process for setting the specified timing is performed by assuming that the inversion timing of the corresponding one of the comparison signals Uc, Vc, and Wc is the zero cross timing from the most advanced timing to the start of the permission period. That is, based on the period from the previous zero cross timing to the currently assumed zero cross timing, the specified timing setting counter value is set so as to be a value corresponding to the required time from the current time to the specified timing.

  When the processes of steps S102 and S104 are completed, the processes of steps S56 to S64 in FIG. 6 are performed.

  As described above, according to the present embodiment, by setting the most advanced angle timing, even when the zero cross timing appears before the start of the permission period, the timing as close as possible to the actual zero cross timing is used. A specified timing can be set. For this reason, the efficiency fall in the output control of the brushless motor 10 can be suppressed suitably. In addition, since the abnormality of the rotational state is determined by the occurrence of the zero cross timing continuously on the advance side of the permission period, this determination can also be made appropriately.

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

  In the first embodiment, the count speeds of the permission start counter and the permission period setting counter are corrected according to the change amount ΔVB of the voltage of the battery 14, but the voltage VB of the battery 14 is corrected as shown in FIG. In addition, the count speed may be corrected according to two parameters of the change amount ΔVB. FIG. 11 shows a map that defines the relationship between these two parameters and the count speed correction coefficient. Here, the voltage VB of the battery 14 is used as a parameter, even if the amount of change ΔVB in the voltage of the battery 14 is the same, the degree of change in the rotational speed of the brushless motor 10 differs depending on the voltage VB of the battery 14. This is because it is considered. For this reason, by using two parameters, it is possible to grasp the rotational fluctuation of the brushless motor 10 caused by the fluctuation of the voltage VB of the battery 14 with higher accuracy.

  The parameters for grasping the change in the rotation speed of the brushless motor 10 are not limited to those exemplified in the above embodiments and their modifications. For example, the amount of change in the temperature of the brushless motor 10 (or its equivalent value) may be used in view of the fact that the higher the temperature of the brushless motor 10, the weaker the magnetic flux in the brushless motor 10 and the higher the rotational speed. Further, as shown in FIG. 12, a rotational speed based on these two parameters is used by using a map that defines the relationship between the temperature of the brushless motor 10 and the change amount ΔVB of the voltage of the battery 14 and the correction coefficient of the count speed. You may grasp the change of

  In the first embodiment, even if the processing of FIG. 5 is not performed, by adjusting the threshold value MAX in FIG. 6 or FIG. It is possible to distinguish between the influence of noise and the step-out state.

  The neutral voltage of the brushless motor 10 may be used instead of the reference voltage vref as a virtual neutral voltage. Alternatively, the voltage of the battery 14 may be divided by a resistor to be “½” of the voltage VB of the battery 14.

  When PWM control is used as a control method for the brushless motor 10, for example, in the above-described embodiment, a period during which the switching elements SW1 to SW6 are turned on is set as an on permission period, and the switching elements SW1 to SW6 are turned on / off within this period Can be repeated. However, in this case, since the rotational speed of the brushless motor 10 may change according to the ratio (duty) of the on time to the sum of the on time and the off time, the correction mode of the count speed is determined according to the duty. It is desirable to do.

  The timing at which a predetermined electrical angle is detected based on the induced voltage is not limited to zero cross timing. For example, it may be found in Patent Document 1 above.

  The power source connected to the brushless motor 10 is not limited to the battery 14 and may be a generator.

  The brushless motor 10 is not limited to an on-vehicle fuel pump actuator, and may be an on-vehicle cooling fan actuator.

  -The rotating machine is not limited to a three-phase brushless motor, and may be an electric motor having an arbitrary number of phases. Furthermore, the generator is not limited to the electric motor.

The figure which shows the whole structure of the control system of the brushless motor concerning 1st Embodiment. The time chart which shows the 120 degree electricity supply control aspect concerning the embodiment. The flowchart which shows the procedure of the setting process of the counter for 120 degree electricity supply control concerning the embodiment. The flowchart which shows the operation mode of the switching element concerning the embodiment. 6 is a flowchart showing the procedure of a correction process of the count speed of the counter according to the embodiment. The flowchart which shows the procedure of the judgment process of the step-out state concerning the embodiment. The flowchart which shows the procedure of the judgment process of the step-out state concerning the embodiment. The flowchart which shows the procedure of the correction process of the count speed of the counter concerning 2nd Embodiment. The time chart which shows the setting method of the maximum advance angle counter concerning 3rd Embodiment. The flowchart which shows the procedure of the judgment process of the step-out state concerning the embodiment. The figure which shows the correction | amendment aspect of the count speed of the counter in the modification of the said embodiment. The figure which shows the correction | amendment aspect of the count speed of the counter in the modification of the said embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Brushless motor, 12 ... Inverter, 14 ... Battery, 20 ... Control apparatus.

Claims (14)

Based on the induced voltage of the rotating machine, a power conversion circuit in which a rectifier is connected to each switching element in parallel with each of the positive and negative electrodes of the power source and the rotating machine connected by a switching element is operated. In the control device for a rotating machine that sets a predetermined timing that is a reference for operation of the switching element by detecting a timing at which the electrical angle of the rotating machine becomes a predetermined electrical angle,
Permission period setting means for setting a permission period for allowing detection of the predetermined electrical angle based on a detected value of the terminal voltage of the rotating machine;
Judging means for judging that there is an abnormality in the rotating state of the rotating machine when the number of times the predetermined electrical angle continuously appears on either the advance side or the retard side of the permission period is equal to or greater than a threshold value; A control device for a rotating machine.   The timing at which the predetermined electrical angle is reached is a zero cross timing at which the induced voltage of the rotating machine becomes a reference voltage, and the zero cross timing is a magnitude relationship between the detected value of the terminal voltage of the rotating machine and the reference voltage. The control device for a rotating machine according to claim 1, wherein the control device is detected based on Means for determining whether or not the zero-cross timing appears on the advance side of the permission period;
3. The control of a rotating machine according to claim 2, wherein, when it is determined that an appearance has appeared on the advance side of the permission period, the specified timing is set assuming that the start time of the permission period is the zero cross timing. apparatus. Means for determining whether or not the zero-cross timing appears on the advance side of the permission period;
Further comprising means for setting a most advanced timing that can be adopted as the zero-cross timing on the more advanced side than the permission period;
When it is determined that the zero cross timing appears on the advance side of the permission period, the specified timing is set assuming that the zero cross timing is a timing between the most advanced angle timing and the start of the permission period. The control device for a rotating machine according to claim 2, wherein: Means for determining whether or not the zero-cross timing appears on the retard side of the permission period;
5. The predetermined timing is set by assuming that the end of the permission period is the zero cross timing when it is determined that it appears on the retard side of the permission period. The control apparatus of the described rotating machine. Comparing means for outputting a binary signal corresponding to the magnitude relationship between the terminal voltage and the reference voltage,
The determination means determines whether or not the zero cross timing appears on the advance side of the permission period based on the value of the binary signal at the start of the permission period, and determines a logical value within the permission period. 6. The control device for a rotating machine according to claim 2, wherein it is determined whether or not the zero-crossing timing appears on a more retarded side than the permission period based on whether or not there is a change.   The permission period setting means is based on the rotation speed of the rotating machine and the change in the rotation speed of the rotating machine, which are grasped from the detected value of the time interval between adjacent timings that become the predetermined electrical angle. The control device for a rotating machine according to any one of claims 1 to 6, further comprising means for setting a required time from the electrical angle to the permission period.   8. The control device for a rotating machine according to claim 7, wherein the change in the rotation speed is grasped by a change in a detected value of the voltage of the power source. Based on the detection result of the timing at which the predetermined electrical angle is reached, comprising extraction means for extracting information relating to the change in the rotational speed;
8. The rotating machine control device according to claim 7, wherein the change in the rotation speed is grasped by the extracted information. Based on the induced voltage of the rotating machine, a power conversion circuit in which a rectifier is connected to each switching element in parallel with each of the positive and negative electrodes of the power source and the rotating machine connected by a switching element is operated. In the control device for a rotating machine that sets a predetermined timing that is a reference for operation of the switching element by detecting a timing at which the electrical angle of the rotating machine becomes a predetermined electrical angle,
Comprising permission period setting means for setting a permission period for permitting detection of the predetermined electrical angle based on a detected value of the terminal voltage of the rotating machine,
The permission period setting means is based on the rotation speed of the rotating machine and the change in the rotation speed of the rotating machine, which are grasped from the detected value of the time interval between adjacent timings that become the predetermined electrical angle. A rotating machine control device comprising means for setting a required time from an electrical angle to the permission period.   11. The rotating machine control device according to claim 10, wherein the change in the rotation speed is grasped by a change in a detected value of the voltage of the power source. Based on the detection result of the timing at which the predetermined electrical angle is reached, comprising extraction means for extracting information relating to the change in the rotational speed;
The control device for a rotating machine according to claim 10, wherein the change in the rotation speed is grasped by the extracted information.   The timing at which the predetermined electrical angle is reached is a zero cross timing at which the induced voltage of the rotating machine becomes a reference voltage, and the zero cross timing is a magnitude relationship between the detected value of the terminal voltage of the rotating machine and the reference voltage. It detects based on, The control apparatus of the rotary machine in any one of Claims 10-12 characterized by the above-mentioned.   The rotating machine control device according to claim 1, wherein the rotating machine is an actuator of a fuel pump that supplies fuel to an internal combustion engine mounted on a motorcycle.

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