JP5125339B2 - Control device for multi-phase rotating machine - Google Patents

Description

  The present invention relates to a control device for a multi-phase rotating machine that controls the multi-phase rotating machine by operating a power conversion circuit that connects each of a positive electrode and a negative electrode of a power source and each phase of the multi-phase rotating machine with a switching element. About.

  FIG. 12 shows a method of controlling a conventional three-phase brushless motor (multi-phase rotating machine) by a 120 ° energization method. Specifically, FIG. 12A shows transitions of the terminal voltages vu, vv, and vw, and FIG. 12B shows terminal voltages vu, vv, and vw indicated by solid lines in FIG. FIG. 12C shows the transition of the comparison signals PU, PV, PW for comparing the magnitude relationship with the reference voltage vref indicated by the chain line, and FIG. 12C shows a 1-bit synthesized signal obtained by logically synthesizing the comparison signals PU, PV, PW. FIG. 12 (d) shows the transition of a signal (detection signal Qs) obtained by shaping the synthesized signal PS.

  The output of the comparison signals PU, PV, PW is inverted at the timing (zero cross timing) at which the terminal voltages vu, vv, vw indicated by solid lines in FIG. 12A coincide with the reference voltage vref indicated by the one-dot chain line. To do. However, in actuality, even when the operation of the switching element of the inverter (power conversion circuit) connected to the brushless motor is switched, the current flows through the diode connected in parallel with the switching element. The outputs of PV and PW are inverted. For this reason, the rising edge and the falling edge of the composite signal PS obtained by logically synthesizing the comparison signals PU, PV, and PW include not only those that coincide with the zero cross timing but also those that coincide with the timing when the current flows through the diode. Yes. On the other hand, the rising edge and falling edge of the detection signal Qs, which is a signal after waveform shaping, all coincide with the zero cross timing.

  Here, the electrical angle of the brushless motor is uniquely determined by the zero cross timing. For this reason, it is possible to control the brushless motor by the 120 ° energization method by switching the operation state of the switching element when the required time from the zero cross timing to the predetermined angle interval (for example, 30 degrees) has elapsed (specified timing). it can. That is, since the time-series pattern for the operation of the switching element is determined in advance, the control by the 120 ° energization method can be realized by operating the switching element according to the above pattern every time the specified timing comes.

In addition, as a conventional control device for a multiphase rotating machine, there is one described in Patent Document 1 below, for example, in addition to the above one.
Japanese Patent No. 2642357

  By the way, since the detection signal Qs is a 1-bit signal, it cannot be identified which zero-crossing timing of the three-phase brushless motor. For this reason, if an abnormality occurs in the rotation state of the brushless motor or noise is mixed in the terminal voltages vu, vv, vw, etc., the controllability of the brushless motor may be greatly reduced. That is, for example, even when the brushless motor rotates in the reverse direction, it is difficult to detect the reverse rotation from the detection signal Qs. Therefore, when the required time has elapsed from the rising edge or the falling edge of the detection signal Qs. There is a possibility that the switching of the operation of the switching element at the (predetermined timing) may be continued as in the normal time. In this case, the brushless motor cannot be appropriately controlled.

  Further, for the purpose of controlling the output of the brushless motor or limiting the current flowing through the brushless motor, the process of repeating the ON / OFF operation of the switching element during the ON period of the ON operation of the switching element defined based on the specified timing. Is known to do. However, during this processing, due to frequent switching of the switching element from the on state to the off state, current frequently flows through the diode, and thus the comparison signals PU, PV, PW and the composite signal PS are frequently inverted. . At this time, since it is difficult to generate the detection signal Qs as an appropriate signal synchronized with the zero cross timing, it is difficult to set the specified timing appropriately.

  The present invention has been made to solve the above-mentioned problems, and its purpose is to provide more accurate information on the electrical angle of a multiphase rotating machine based on a comparison between an induced voltage of the multiphase rotating machine and a reference voltage. It is an object of the present invention to provide a control device for a multi-phase rotating machine that can be obtained.

  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, each of the positive and negative electrodes of the power source and the multi-phase rotating machine are switched to control the multi-phase rotating machine based on a zero cross timing at which the induced voltage of the multi-phase rotating machine becomes a reference voltage. In a control device for a multi-phase rotating machine that operates with a power conversion circuit that is connected by an element and in which a rectifying means is connected in parallel to each of the switching elements , the terminal voltage for each phase of the multi-phase rotating machine Comparing means for comparing the magnitude relationship between the neutral point voltage of the multiphase rotating machine and a reference voltage set to one of its equivalent values, and the zero cross timing in the current operating state of the switching element, Information on the electrical angle of the multi-phase rotating machine based on the comparison for each phase about the comparison result by the comparison means assumed when and the actual comparison result Obtaining means, wherein the obtaining means comprises means for detecting the zero-crossing timing based on at least one phase match between the assumed comparison result and the actual comparison result, and based on the zero-crossing timing, The apparatus further comprises setting means for setting a prescribed timing as a reference for switching the operating state of the switching element, wherein the prescribed timing and the zero-cross timing are associated with each other in a one-to-one correspondence, and each switching element determined by the prescribed timing In the ON operation permission period, further comprising an operation means for repeatedly turning on and off the switching element in the ON operation permission period, and in a period during which processing by the operation means is performed, the switching element is fixed to an ON state. The phase to which the switching element is connected A comparison result of the comparing means Te is based on whether showing the inversion of the magnitude relationship, and further comprising disconnection detecting means for detecting the phase existence of disconnection of the line of the multi-phase rotary machine.

  In which phase the zero cross timing is reached depends on the switching operation state. For this reason, the comparison result of the comparison means for each phase at the zero cross timing can be determined in advance depending on the switching operation state. In the above invention, paying attention to this point, the comparison result (presumed comparison result) determined in advance and the actual comparison result are compared for each phase. According to the comparison for each phase, more detailed information can be used as compared with the case where a signal obtained by combining the comparison results of all phases into one bit is used. Can be obtained.

In the above invention, the zero cross timing is detected based on the coincidence of at least one phase between the assumed comparison result and the actual comparison result, so that, for example, the comparison is performed on the phase on which the induced voltage and the reference voltage are assumed to coincide. The results can be used selectively. For this reason, compared with the case where the change time of the signal obtained by synthesizing the comparison results of all phases into one bit is set as the zero cross timing, the condition for setting the zero cross timing can be made stricter. For this reason, the zero cross timing can be detected with high accuracy.

By the way, the zero cross timing occurs at every predetermined period for the electrical angle of the multiphase rotating machine. For this reason, in the said invention, a prescription | regulation timing can be set appropriately based on a zero crossing timing.

In the above invention, the specified timing and the zero cross timing correspond one-to-one. For this reason, there is a one-to-one correspondence between the operating state of the switching element and the zero cross timing. Therefore, in the said invention, the comparison result of the comparison means assumed when it becomes a zero cross timing in the present operation state of a switching element can be defined uniquely.

By the way, when the process by the operation means is performed, the voltage of the phase at which the switching element is switched from the on state to the off state is rapidly changed to the positive electrode potential side or the negative electrode potential side. Specifically, the voltage drop by the rectifying means is higher than the positive electrode potential or lower than the negative electrode potential. At this time, the voltage of the phase in which the switching element is turned off also changes to the positive electrode potential side or the negative electrode potential side. For this reason, the neutral point voltage as a reference voltage or its equivalent value may be higher than the positive electrode potential or lower than the negative electrode potential.

  When a neutral point voltage or the like is used as the reference voltage, the phase in which the switching element is turned off, that is, the phase in which the induced voltage and the terminal voltage can coincide with each other regardless of the processing by the operating means. The comparison result of the comparison means does not change until the zero cross timing is reached. However, when the processing by the operation means is being performed, the comparison result of the comparison means frequently changes at least in the phase in which the processing is performed, so the comparison result of any one of the comparison results by the comparison means changes. Therefore, the zero cross timing cannot be detected.

In this regard, in the above invention, in order to detect the zero cross timing based on the phase-by-phase comparison between the assumed comparison result and the actual comparison result, the comparison result of the comparison means in the phase where the induced voltage and the terminal voltage can coincide. Can also be used. For this reason, it is possible to grasp the zero cross timing with high accuracy even when the processing by the operation means is performed.
As described above, the voltage of the phase at which the switching element is switched from the on state to the off state by the processing by the operation unit is higher than the positive electrode potential or lower than the negative electrode potential by about the voltage drop of the rectifier unit. For this reason, the reference voltage is also higher than the positive electrode potential or lower than the negative electrode potential. However, when the multi-phase rotating machine is disconnected, it is considered that the reference voltage does not become higher than the positive electrode potential or lower than the negative electrode potential. For this reason, it is considered that the comparison results of the comparison means of the phase fixed in the on state, that is, the phase in which the terminal voltage is fixed at the positive electrode potential or the negative electrode potential, differ depending on the presence or absence of disconnection of the multiphase rotating machine. It is done. In the above invention, in view of this point, it is possible to detect disconnection of the multiphase rotating machine.

According to a second aspect of the invention, in the invention according to the first SL placement, the acquisition means, comparison with the actual comparison of the comparing means in the current operating state is assumed when the zero-cross timing of the switching element An abnormality determination means is provided for determining that there is an abnormality in the rotational state of the multiphase rotating machine based on the fact that the result is inconsistent in at least one phase.

  When the rotation state of the multi-phase rotating machine is normal, it is considered that the assumed comparison result and the actual comparison result coincide in all phases. In the above invention, paying attention to this point, it is determined with high accuracy that there is an abnormality in the rotational state of the rotating machine, based on the fact that the assumed comparison result and the actual comparison result are inconsistent in at least one phase. be able to.

According to a third aspect of the present invention, in the second aspect of the invention, the abnormality determination unit is configured to change the time series pattern of the comparison result of the comparison unit assumed from the time series pattern of the operation state of the switching element with respect to time. And a means for judging that there is an abnormality that the multiphase rotating machine rotates in reverse based on the coincidence between the inverted one and the actual time series pattern.

  The comparison result of the comparison means is determined from the operating state of the switching element. For this reason, the time series pattern of the comparison result of the comparison means can be determined by the time series pattern of the operation state of the switching element. For this reason, when the time series pattern of the comparison result is reversed and the actual time series pattern matches, it can be determined that the multiphase rotating machine is rotating in reverse.

According to a fourth aspect of the present invention, in the second or third aspect of the invention, when it is determined that there is an abnormality in the rotational state of the multiphase rotating machine, the rotation of the multiphase rotating machine is forcibly stopped. And a starting means for restarting the multiphase rotating machine after the stopping process by the stopping means.

  In the above invention, when it is determined that there is an abnormality in the rotational state of the multiphase rotating machine, the process of forcibly stopping the rotation of the multiphase rotating machine is performed, and then the restarting process is performed. For this reason, compared with the case where restart processing is performed after waiting until the multiphase rotating machine naturally stops, the multiphase rotating machine can be quickly returned to the normal state.

According to a fifth aspect of the present invention, in the invention according to the fourth aspect , the stopping means forces the rotation of the multiphase rotating machine by causing all phases of the multiphase rotating machine to conduct with either the positive electrode or the negative electrode. It stops automatically.

  When all phases of the multiphase rotating machine are brought into conduction with either the positive electrode or the negative electrode, all phases of the multiphase rotating machine are short-circuited. In this case, a current flows through the multiphase rotating machine due to the induced voltage accompanying the rotation of the multiphase rotating machine, and this current attenuates due to 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 multi-phase rotating machine can be rapidly reduced by making all phases of the multi-phase rotating machine conductive with either the positive electrode or the negative electrode of the power source.

According to a sixth aspect of the present invention, there is provided a multiphase rotating machine that detects a disconnection of a phase line of a multiphase rotating machine connected to the power conversion circuit with respect to a power conversion circuit including a switching element and a rectifying means connected in parallel thereto. For each of the phases of the multiphase rotating machine, the magnitude relationship between the terminal voltage and the reference voltage consisting of either the neutral point voltage of the multiphase rotating machine or its equivalent value is separately determined. Comparing means for comparing, and at least one of the phases of the multiphase rotating machine is in a conductive state with any one of the pair of input terminals of the power conversion circuit and at least one other than the single phase In a situation where a phase is in a conductive state with either one of the pair of input terminals, at least when the switching element that turns the one of the input terminals and the multiphase rotating machine into a conductive state is turned off One A comparison result of said comparing means for correspondence on the basis of whether or not showing the inversion of the magnitude relationship, characterized by comprising a disconnection detection means for detecting the presence or absence of the disconnection.

  A single phase of the phases of the multiphase rotating machine is in conduction with one of the pair of input terminals of the power conversion circuit, and at least one phase other than the single phase is any of the pair of input terminals. When the switching element that makes one of the input terminals and the multi-phase rotating machine conductive is turned off in a state where it is in a conductive state with the other, a single phase has a current via a rectifier. Continues to flow. For this reason, the voltage of a single phase rises to a value higher than the positive electrode potential of the power supply, or falls to a value lower than the negative electrode potential of the power supply. For this reason, the reference voltage also rises to a value higher than the positive potential of the power supply or falls to a value lower than the negative potential of the power supply.

  However, when the multi-phase rotating machine is disconnected, the voltage of a single phase is not supplied even if the switching element that makes one of the input terminals and the multi-phase rotating machine conductive is turned off. It remains at a value between the positive electrode potential and the negative electrode potential. For this reason, the comparison result of the comparison means in at least one phase, that is, the phase in which the terminal voltage is fixed at the positive electrode potential or the negative electrode potential, differs depending on whether or not the multiphase rotating machine is disconnected. In the above invention, it is possible to detect a disconnection by focusing on this point.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, based on a zero cross timing at which an induced voltage of the multiphase rotating machine matches the reference voltage, a specified timing that serves as a reference for switching the operation state of the switching element. When the phase current of the multiphase rotating machine is greater than or equal to a threshold value, the on / off state of the switching element in the on operation permission period is determined in the on operation permission period of each switching element determined by the specified timing. The disconnection detecting means performs the detection when processing by the operating means is performed.

  In the above invention, when the phase current is less than the threshold value, the on / off operation is switched based on the specified timing. In this case, the reference voltage is considered to remain between the positive electrode potential and the negative electrode potential. On the other hand, when the operation means is operated, a single phase of the phases of the multi-phase rotating machine is in a conductive state with any one of the pair of input terminals of the power conversion circuit and other than the single phase. In a situation where at least one phase is in a conductive state with either one of the pair of input terminals, a phenomenon occurs in which a switching element that makes one of the input terminals and the multiphase rotating machine into a conductive state is turned off. obtain. For this reason, the invention described in claim 13 can be applied appropriately.

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

  FIG. 1 shows an overall configuration of a brushless motor control system 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.

  In the present embodiment, the switching elements SW1, SW3, and SW5 in the upper arm are configured by P-channel MOS transistors, and the switching elements SW2, SW4, and SW6 in the lower arm are configured by N-channel MOS transistors. Yes. 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 virtual neutral point voltage (reference voltage vref), which is a divided value by the resistors RU, RV, RW for the terminal voltages vu, vv, vw of each phase of the brushless motor 10, is determined for each phase of the brushless motor 10. The timing at which the induced voltage coincides with the reference voltage vref (zero cross timing) is detected based on the timing coincident with the terminal voltages vu, vv, vw. 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 detection unit 24 exceeds the current limit value, a period during which the switching elements SW2, SW4, SW6 are turned on to limit the current (energization amount) flowing through the brushless motor 10 is set. Instead of setting the period of “120 °”, PWM control is performed within this period.

  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, transitions of the terminal voltages vu, vv, vw are shown by solid lines, and a reference voltage vref is shown by a one-dot chain line (in this embodiment, a virtual neutral point voltage is used as the reference voltage vref). In this case, the reference voltage vref actually fluctuates, but is a constant value for convenience here). FIG. 2B shows the transition of the comparison results (comparison signals PU, PV, PW) of the respective magnitude relationships between the terminal voltages vu, vv, vw and the reference voltage vref, and FIG. The transition of the logic synthesis signal PS of PU, PV, and PW is shown. FIG. 2D shows the transition of the logic synthesis signal (expected signal) of the comparison signals PU, PV, and PW that is assumed when the zero cross timing is reached in the operating state of the switching elements SW1 to SW6. FIG. 2E shows a transition of the detection signal Qs at the zero cross timing, which is a signal in which the rising edge and the falling edge are synchronized with the zero cross timing. FIG. 2 (f) shows changes of various counters, and FIG. 2 (g) shows changes of operation signals of the switching elements SW1 to SW6. 2 (g) includes the operation signals U +, V +, W + of the switching elements SW1, SW3, SW5 of the upper arm and the operation signals U− of the switching elements SW2, SW4, SW6 of the lower arm. 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.

  The composite signal PS is a 3-bit signal, and the logical values of the comparison signals PU, PV, and PW respectively match the logical values of the most significant bit, the intermediate bit, and the least significant bit. That is, when the comparison signal PU is logic “H”, the most significant bit is “1”, and when the comparison signal PU is logic “L”, the most significant bit is “0”. Therefore, for example, when the comparison signals PU, PV, and PW are “H”, “L”, and “H”, respectively, the composite signal PS is “101” in binary notation and “5” in decimal notation. . Incidentally, in FIG. 2, both the synthesized signal PS and the expected signal are shown in decimal notation.

  A solid line in FIG. 2 (f) indicates a 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. 2 (f) 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, 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, a two-dot chain line in FIG. 2 (f) indicates 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 before becoming zero as a masking period. Here, for example, if the masking 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.

  When the masking period counter becomes zero, the comparison signals PU, PV, PW and the combined signal PS are validated. In this period, the detected signal Qs is inverted when the combined signal PS matches the expected signal. Then, the decrement of the specified timing setting counter is started from the zero cross timing at which the detection signal Qs is inverted, and the operation of the switching elements SW1 to SW6 is switched when the value becomes zero.

  As shown in the figure, the prescribed timing for switching each of the switching elements SW1 to SW6 to the ON state and the zero cross timing correspond one-to-one. For this reason, the behavior of the terminal voltages vu, vv, vw of each phase is uniquely determined according to the operation state of the switching elements SW1 to SW6. For this reason, the expected signal can be uniquely determined.

  Hereinafter, the processing procedure of the 120 ° energization control according to the present embodiment will be further described with reference to FIGS. 3 and 4. FIG. 3 shows the 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 or not the combined signal PS of the comparison signals PU, PV, and PW has changed. When it is determined in step S12 that the combined signal PS has changed, it is determined in step S14 whether or not the combined signal PS matches the expected signal. This process determines whether the change in the magnitude relationship between the terminal voltages vu, vv, vw and the reference voltage vref matches the change assumed from the operating state of the switching elements SW1 to SW6. When it is determined that the combined signal PS and the expected signal match, it is determined whether or not the inversion permission flag is on. Here, the inversion permission flag is a flag that is turned on when the detection signal Qs is not yet inverted after the masking period counter becomes zero. For this reason, when the combined signal PS and the expected signal match for the first time after the masking period counter becomes zero, the inversion permission flag is turned on.

  When the inversion permission flag is on, the detection signal Qs is inverted in step S18. In step S20, the inversion permission flag is turned off. In subsequent step S22, the values of the specified timing setting counter and the masking period counter are set as the values of the measurement counter. In step S24, the measurement counter is initialized.

  On the other hand, when a negative determination is made in step S10, the measurement counter is incremented in step S26. In the subsequent step S28, it is determined whether or not the specified timing setting counter is zero. When the specified timing setting counter is zero, the inversion permission counter is turned on in step S30. On the other hand, when the specified timing setting counter is not zero, the specified timing setting counter is decremented in step S32.

  When the processes in steps S30 and S32 are completed, it is determined in step S34 whether the masking period counter is zero. If the masking period counter is not zero, the masking period counter is decremented in step S36.

  When an affirmative determination is made in step S34 or a negative determination is made in steps S12 to S16, when the process of step S36 is completed, this series of processes is temporarily terminated.

  FIG. 4 shows the procedure of the switching process of the operations of the switching elements SW1 to SW6 during the 120 ° energization control based on the specified timing setting counter. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processing, first, in step S40, it is determined whether or not the specified timing setting counter has become zero. This process is to determine whether or not it is the timing for switching the operation of the switching elements SW1 to SW6. When it is determined that the specified timing setting counter has become zero, in step S42, the operation of the switching elements SW1 to SW6 is switched based on the operation pattern (switching pattern) of the switching elements SW1 to SW6. That is, as shown in FIG. 2, the operation pattern of the switching elements SW1 to SW6 changes every “60 °” in electrical angle, but has a periodicity of “360 °” period. Yes. For this reason, the next operation state is uniquely determined from the current operation state of the switching elements SW1 to SW6. For this reason, operation of switching element SW1-SW6 is switched based on this unambiguous relationship.

  In a succeeding step S44, the expected signal is updated. That is, it is considered that the zero cross timing occurs once in the period in which the operation state is maintained by changing the operation state of the switching elements SW1 to SW6. The values of the comparison signals PU, PV, PW at this zero cross timing are uniquely determined from the operation state. Therefore, the expected signal is updated to a value corresponding to the current operation state. Specifically, when the previous expected signal is “1”, the current expected signal is “5”, and when the previous expected signal is “5”, the current expected signal is “4”. When the previous expected signal is “4”, the current expected signal is “6”, and when the previous expected signal is “6”, the current expected signal is “2”. When the signal is “2”, the current expected signal is “3”, and when the previous expected signal is “3”, the current expected signal is “1”.

  When a negative determination is made in step S40 or when the process of step S44 is completed, this series of processes is temporarily terminated.

  According to the said process, 120 degree electricity supply control can be performed appropriately.

  FIG. 5 shows the processing procedure of the PWM control described above. This process is repeatedly executed by the control device 20 at a predetermined cycle, for example.

  In this series of processes, first, in step S50, the current detection unit 24 shown in FIG. 1 determines whether or not the maximum value of the current flowing through each phase of the brushless motor 10 exceeds a threshold value. This threshold value may be set based on, for example, the maximum value of current allowed for the switching elements SW1 to SW6. When it is determined that the threshold value is exceeded, in step S52, the switching elements SW2, SW4, SW6 of the lower arm of the inverter 12 are repeatedly turned on / off within the on period (on permission period) determined by the specified timing. Perform PWM processing. When a negative determination is made in step S50 or when the process of step S52 is completed, the series of processes is temporarily terminated.

  When the PWM control is performed, the terminal voltages vu, vv, and vw frequently change. However, according to the processing shown in FIG. 3, the zero cross timing can be detected with high accuracy even in this case. FIG. 6 shows a switching control mode during PWM control. 6A to FIG. 6E correspond to the previous FIG. 2A to FIG. 2E.

  In the figure, the PWM control is performed during the ON operation permission period of the U-phase lower arm switching element SW2 (ON state period during 120 ° energization control). As shown in the drawing, the U-phase terminal voltage vu rises higher than the positive voltage VB of the battery 14 every time the switching element SW2 is switched from the on state to the off state. This is because, due to the inductance component of the brushless motor 10, when the switching element SW <b> 2 is switched from the on state to the off state, a voltage is generated that keeps the current flowing in the U phase when it is in the on state. is there. At this time, since both the U-phase switching elements SW1 and SW2 are in the OFF state, a current flows to the U-phase via the diode D1. For this reason, the U-phase terminal voltage vu is higher than the positive voltage VB of the battery 14 by about the amount of voltage drop of the diode D1.

  At this time, since the W-phase switching elements SW5 and SW6 are both off, the W-phase is in a high impedance state. The W-phase terminal voltage vw at this time is raised by the V-phase terminal voltage vv that is equal to the positive voltage VB of the battery 14 and the U-phase terminal voltage vu when the switching element SW3 is turned on. Therefore, it becomes higher than the positive electrode voltage VB of the battery 14. For this reason, the reference voltage vref set by the virtual neutral point becomes higher than the positive voltage VB of the battery 14 every time the switching element SW2 is switched to the OFF state. The reference voltage vref is lower than the U-phase terminal voltage vu when the switching element SW2 is switched to the OFF state, but is higher than the W-phase terminal voltage vw at that time. For this reason, the W-phase terminal voltage vw remains lower than the reference voltage vref until the W-phase induced voltage becomes equal to or higher than the reference voltage vref.

  As a result, the comparison signal PW becomes logic “H” only when the zero cross timing is reached. Therefore, as shown in FIG. 3, the detection signal Qs is inverted when the synthesized signal PS matches the expected signal for the first time, thereby associating the inversion timing of the detection signal Qs with the zero-cross timing on a one-to-one basis. Can do. Incidentally, a phenomenon may occur in which the W-phase terminal voltage vw when the switching element SW2 is switched to the off state alternately takes a value higher and lower than the reference voltage vref. The timing at which the signal PS and the expected signal coincide for the first time can be set as the zero cross timing. This is because in this case, only “5” is used instead of the combined signal “4” in the figure.

  On the other hand, as shown in FIG. 12, when a 1-bit composite signal is generated from the comparison signals PU, PV, and PW, the composite signal is frequently inverted during PWM control. The zero cross timing cannot be detected.

  Actually, the comparison signal PW may instantaneously become logic “H” before the zero cross timing due to ringing noise accompanying switching of operations of the switching elements SW1 to SW6. However, in this case, since the logical value of the comparison signal PU tends to be different from that shown in FIG. 6, there is a possibility that the 3-bit synthesized signal PS and the expected signal match before the zero cross timing. It can be kept low.

  However, in order to more reliably avoid erroneous determination of the zero-cross timing due to the influence of ringing noise, it is desirable that a value whose duration is not more than a predetermined value among the values of the synthesized signal PS is not to be compared with an expected signal. This processing can be realized by, for example, sampling the synthesized signal PS at a high-speed sampling period, and removing values that do not have the same value more than once in adjacent sampling periods as noise influences. Further, the erroneous determination can be avoided more reliably by performing a process for slightly offset correcting the reference voltage vref generated by the virtual neutral point.

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

  (1) For each phase of the combined signal (expected signal) of the comparison signals PU, PV, PW and the actual combined signal PS assumed when the zero cross timing is reached in the current operation state of the switching elements SW1 to SW6 Based on the comparison, information on the electrical angle of the brushless motor 10 was obtained. As a result, more detailed information can be used as compared with the case of using a 1-bit composite signal of the comparison signals PU, PV, and PW, so that highly accurate information about the electrical angle can be acquired.

  (2) Based on the all-phase coincidence between the values of the assumed comparison signals PU, PV, PW and the actual values, in other words, based on the coincidence of all the bits of the 3-bit synthesized signal PS and the expected signal, Zero cross timing was detected. As a result, the condition for setting the zero cross timing can be made stricter as compared with the case of changing the signal obtained by combining the comparison results of all phases into one bit as the zero cross timing. For this reason, the zero cross timing can be detected with high accuracy.

  (3) Based on the zero cross timing, a prescribed timing that is a reference for switching the operation state of the switching elements SW1 to SW6 is set. Thereby, the specified timing can be set appropriately.

  (4) The specified timing and the zero-cross timing are associated with each other on a one-to-one basis. As a result, the operation states of the switching elements SW1 to SW6 also correspond to the zero-cross timing on a one-to-one basis. Therefore, the comparison signals PU, PV, and PW (expected signals) that are assumed when the zero cross timing is reached in the current operation state of the switching elements SW1 to SW6 can be uniquely determined.

  (5) When the reference voltage vref is set by the virtual neutral point voltage of the brushless motor 10 and the current flowing through the brushless motor 10 is excessively large, in the ON operation permission period determined by the specified timing PWM control for switching between on and off operations was performed. In this case, the zero cross timing cannot be detected by the 1-bit logic synthesis signal of the comparison signals PU, PV, and PW. On the other hand, according to the present embodiment, the zero-cross timing can be grasped with high accuracy based on the comparison between the expected signal that is a 3-bit signal and the synthesized signal PS.

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

  When the connection state between the battery 14 and the inverter 12 is insufficient, for example, the vibration of the vehicle is transmitted to the battery 14, so that the battery 14 and the inverter 12 are instantaneously switched from the conductive state to the conductive state again. There is a possibility that the phenomenon of recovery will occur. At this time, if the power supply to the brushless motor 10 is temporarily interrupted, the rotational speed of the brushless motor 10 is reduced. At this time, the fuel discharged from the fuel tank side to the upstream side by the fuel pump flows backward, whereby a force on the reverse rotation side is exerted on the brushless motor 10 and thus reverse rotation may occur. Under such circumstances, if the switching elements SW1 to SW6 are operated in the same manner as normal, an oscillation phenomenon in which the brushless motor 10 repeats normal rotation and reverse rotation occurs, and the brushless motor 10 is brought into an appropriate rotation state. It becomes difficult to control.

  Here, it can be appropriately determined that the brushless motor 10 is rotating in the reverse direction based on the composite signal PS composed of 3 bits. That is, as shown in FIG. 7, when the brushless motor 10 is rotating forward, the time series data of the composite signal PS should match the time series data of the expected signal. On the other hand, when the brushless motor 10 is rotating in the reverse direction, the time series data of the composite signal PS should match the data obtained by time-reversing the time series data of the expected signal. For this reason, reverse rotation of the brushless motor 10 can be determined based on the composite signal PS.

  Here, there is a technique in which all of the switching elements SW1 to SW6 are turned off when the rotation state of the brushless motor 10 becomes abnormal, the brushless motor 10 waits until it stops, and is restarted after stopping. However, in this case, it takes a long time to return the brushless motor 10 to a normal state.

  Therefore, in this embodiment, when it is detected that the brushless motor 10 is rotating in the reverse direction, a process for forcibly stopping the rotation of the brushless motor 10 is performed, and then a restart process is performed. This will be described in detail below. FIG. 8 shows a procedure of processing related to restart 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.

  In this series of processing, first, in step S60, it is determined whether or not the masking period counter is zero. If it is determined that the masking period counter is zero, it is determined in step S62 whether or not the combined signal PS of the comparison signals PU, PV, and PW has changed. This process determines whether or not the zero cross timing is reached. If it is determined that the combined signal PS has changed, it is determined in step S64 whether or not the current combined signal matches the previous expected signal. This process determines whether or not the brushless motor 10 is rotating in the reverse direction. That is, as shown in FIG. 7, when the brushless motor 10 rotates in reverse, the time series data of the composite signal PS is inverted, so that the current composite signal PS is the same as the expected signal of the previous time. It is considered that they match. If the current synthesized signal PS matches the expected signal of the previous time, it is determined in step S66 that the brushless motor 10 is rotating in reverse.

  In the subsequent step S68, a process for forcibly stopping the rotation of the brushless motor 10 is performed. Specifically, all the phases of the brushless motor 10 are short-circuited by turning on all the switching elements SW1, SW3, SW5 or the switching elements SW2, SW4, SW6. As a result, a current flows through the brushless motor 10 only by the induced voltage generated as the brushless motor 10 rotates, and this current is quickly attenuated by the resistance of the current flow path and the like. Thereby, the rotational energy of the brushless motor 10 is attenuated after being converted into electric energy. For this reason, the brushless motor 10 can be stopped quickly.

  When the rotational speed of the brushless motor 10 becomes substantially zero (step S70: YES), a restart process is performed in step S72. Incidentally, the rotational speed of the brushless motor 10 is calculated based on the interval between adjacent zero cross timings. This can be done by using the maximum value of the measurement counter.

  When a negative determination is made in steps S60 to S64, or when the process of step S72 is 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 effect (1) of the first embodiment.

  (6) Based on the mismatch between the synthesized signal PS assumed when the zero cross timing is reached in the current operation state of the switching elements SW1 to SW6 and the expected signal, it is determined that the rotational state of the brushless motor 10 is abnormal. As described above, by using the 3-bit composite signal PS and the 3-bit expected signal, it is possible to appropriately determine whether there is an abnormality.

  (7) Based on the coincidence of the time series pattern of the synthesized signal PS assumed from the time series pattern of the operating states of the switching elements SW1 to SW6 with respect to time and the actual time series pattern, the brushless motor 10 It was judged that there was an abnormality that reversely rotated. Thereby, it can be appropriately determined that the brushless motor 10 is rotating in the reverse direction.

  (8) When it is determined that the brushless motor 10 is rotating in the reverse direction, a process for forcibly stopping the brushless motor 10 is performed, and then the brushless motor 10 is restarted. Thereby, the brushless motor 10 can be quickly returned to a normal state.

  (9) The brushless motor 10 was forcibly stopped by conducting all phases of the brushless motor 10 with either the positive electrode or the negative electrode. Thereby, the rotational energy of the brushless motor 10 can be reduced rapidly.

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

  When one of the phase lines of the brushless motor 10 is disconnected, a voltage is applied to the phase where the brushless motor 10 is not disconnected by the inverter 12, but the current flow is hindered and an excessive load is applied to the brushless motor 10. There is a fear. On the other hand, as seen in, for example, Japanese Patent Application Laid-Open No. 2-290191, it has been proposed to determine whether or not a phase current flows using a shunt resistor and thereby detect the presence or absence of a disconnection. However, in this case, a member for sensing the voltage drop amount of the shunt resistor is required, and the circuit scale of the control device 20 may increase.

  Therefore, in the present embodiment, the presence / absence of disconnection is detected using the behavior of the comparison signals PU, PV, and PW. Since these comparison signals PU, PV, and PW are taken into the control device 20 to be used for the operation of the switching elements SW1 to SW6, an increase in circuit scale can be avoided by detecting disconnection using them. Can do. In the following, first, the principle of disconnection detection using the comparison signals PU, PV, and PW will be described.

  FIG. 6 shows the transition of the comparison signals PU, PV, PW during PWM control. Here, since the reference voltage vref exceeds the positive voltage VB of the battery 14 when the switching element to be subjected to PWM control is switched from the on state to the off state, the switching element is fixed in the on state. The comparison signal is logically inverted. However, when the brushless motor 10 is disconnected, the comparison signal is not logically inverted as shown in FIG. Here, FIGS. 9A and 9B correspond to FIGS. 6A and 6B, and the W-phase line of the brushless motor 10 is connected to the resistor RW. The case where it has disconnected on the brushless motor 10 side rather than the point is shown.

  As illustrated, in this case, the W-phase terminal voltage vw decreases to about the negative voltage of the battery 14. In the example shown in FIG. 9, the W phase is in a high impedance state, but the W phase potential is shifted to the negative potential side of the battery 14 due to the parasitic capacitance between the gate and drain of the switching element SW6. It is because it falls. In this case, when switching the switching element SW2 from the off state to the on state, the current flows through the diode D1 and the U-phase terminal voltage vu rises above the positive voltage VB of the battery 14, but the reference voltage vref is It becomes lower than the positive voltage VB of the battery 14. This is because the W-phase terminal voltage vw is lowered due to the disconnection.

  For this reason, regardless of the state of the switching element SW2, the reference voltage vref remains lower than the V-phase terminal voltage vu fixed on the positive electrode voltage VB side of the battery 14. As a result, as shown in FIG. 9B, the V-phase comparison signal PV is always “H”, which is different from the phenomenon shown in FIG. 6B. Therefore, it is possible to detect whether or not the brushless motor 10 is disconnected based on the difference between these phenomena.

  9 illustrates the case where the phase in which the switching elements of both the upper arm and the lower arm are turned off (the phase to be in a high impedance state) is disconnected, the phase to be subjected to PWM control (FIG. 9) In FIG. 9, even if the U phase is disconnected, the disconnection can be detected using the comparison signal PV. This is because the U-phase terminal voltage vu sticks to the negative voltage side of the battery 14 in this case, so that the reference voltage vref does not exceed the positive voltage VB of the battery 14.

  FIG. 10 shows a procedure of disconnection detection processing 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, first, in step S80, it is determined whether or not PWM control, which is the processing in step S52 of FIG. 5, is performed. When it is determined that it is during PWM control, in step S82, the phase corresponding to the switching element SW1, SW3, SW5 of the upper arm that is in the ON operation permission period is specified. By this processing, the V phase is specified in the example of FIG. In a succeeding step S84, it is determined whether or not the specified phase is within the ON permission period. This process is for specifying a period in which the terminal voltage of the phase suitable for use in disconnection detection does not change.

  If it is determined in step S84 that it is within the ON operation permission period, it is determined in step S86 whether or not the logical value of the phase comparison signal specified in step S82 is “L”. This process determines whether or not there is a disconnection. When an affirmative determination is made in step S86, an L detection flag indicating that the logical value has become “L” is turned on in step S88. This process can be performed as a process of changing a register value in the control device 20.

  When the process of step S88 is completed or when a negative determination is made in step S86, the process returns to step S84. On the other hand, when a negative determination is made in step S84, the process proceeds to step S90. In step S90, it is determined whether or not the L detection flag is on. This process is for determining the presence or absence of disconnection. That is, if the comparison signal does not become logic “L” in the on-permission period of the phase specified in step S82, it is considered that the phenomenon shown in FIG. It can be determined that a disconnection has occurred. Therefore, when a negative determination is made in step S90, the control device notifies the outside that a disconnection has been detected in step S92. When the process of step S92 is completed or when a negative determination is made in steps S80 and S90, the L detection flag is turned off in step S94.

  When the process of step S94 is completed, this series of processes is temporarily terminated.

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

  (10) In a situation where the single phase of the brushless motor 10 is in conduction with the negative terminal of the battery 14 and the other phase is in conduction with the positive terminal of the battery 14, the negative terminal and the brushless motor 10 Whether or not the brushless motor 10 is disconnected is detected based on the presence or absence of inversion of the one-phase comparison signal other than that when the switching element that is in the conductive state is turned off. Thereby, the disconnection of the brushless motor 10 can be detected.

  (11) Since the reference voltage vref does not exceed the positive voltage of the battery 14 during 120 ° energization control, disconnection detection is performed during PWM control in view of the fact that disconnection detection based on the comparison signal cannot be performed at this time. Thereby, a disconnection detection can be performed appropriately.

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

  FIG. 11 shows the overall configuration of the control system of the brushless motor 10 according to the present embodiment. In FIG. 11, members corresponding to those shown in FIG. 1 are given the same reference numerals for convenience.

  The illustrated brushless motor 10a is a two-phase motor. In this embodiment, in the two-phase motor, in order to detect the presence or absence of disconnection in the manner shown in the previous third embodiment, in the inverter 12a, the series connection body of the switching elements SW1 and SW2 and the switching elements SW3 and SW4 A series connection body of diodes D5 and D6 is connected in parallel with the series connection body. And the connection point of these diodes D5 and D6 is connected to the neutral point of the brushless motor 10a. As a result, the phase connected to the connection point of switching elements SW1 and SW2 is the U phase, the phase connected to the connection point of switching elements SW3 and SW4 is the V phase, and the phase is connected to the connection point of diodes D5 and D6. With the line as the W phase, the disconnection can be detected in the same manner as in the third embodiment.

  That is, the comparison signal PU by the comparator Cu between the terminal voltage vu and the reference voltage vref, the comparison signal PV by the comparator Cv between the terminal voltage vv and the reference voltage vref, and the comparator Cw between the terminal voltage vw and the reference voltage vref. Based on the comparison signal PW by, disconnection detection can be performed by the same processing as the processing shown in FIG.

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

  In the above embodiment, the specified timing is set by adjusting the decrement speed of the specified timing setting counter with respect to the increment speed of the measurement counter. However, the present invention is not limited to this. For example, the initial value of the specified timing setting counter may be set according to the value (maximum value) before the initialization of the measurement counter while making the count speeds of both the same. Here, for example, when the specified timing is set to a timing delayed by “30 °” from the zero cross timing, the initial value of the specified timing setting counter may be set to “½” of the maximum value of the measurement counter.

  In the above embodiment, the masking period is set by adjusting the decrement speed of the masking period counter with respect to the increment speed of the measurement counter. However, the present invention is not limited to this. For example, the initial value of the masking period counter may be set in accordance with the value (maximum value) before the initialization of the measurement counter while keeping both count speeds the same. Here, for example, when the masking period is an angle region of “45 °” from the zero cross timing, the initial value of the masking period counter may be set to “3/4” of the maximum value of the measurement counter.

  In the first embodiment, the zero cross timing is detected based on the coincidence of all bits of the synthesized signal PS and the expected signal, but the present invention is not limited to this. For example, during PWM control, the zero cross timing may be detected based on the coincidence of the bits corresponding to the phase where the induced voltage and the reference voltage vref cross with zero.

  In the second embodiment, in order to forcibly stop the brushless motor 10, all the phases of the brushless motor 10 are short-circuited. Instead, a torque for stopping the current rotation is generated. Thus, switching control of the switching elements SW1 to SW6 may be performed.

  In the second embodiment, the reverse rotation is determined on the condition that the synthesized signal PS matches the expected signal of the previous time, but in addition to this condition, the next synthesized signal PS is expected to be the previous expected signal. The reverse rotation may be determined when it coincides with the expected signal before the signal.

  The abnormality of the rotation state of the brushless motor 10 is not limited to the reverse rotation described above. In short, if the synthesized signal PS does not match the expected signal, it may be determined that there is an abnormality in the rotational state.

  In each of the above embodiments, the PWM control is performed when the phase current of the brushless motor 10 exceeds the threshold value, but the present invention is not limited to this. For example, the switching element of the lower arm in the on-permitted period may be forcibly turned off only while the current exceeds the threshold value. Also by this, it is possible to configure an operation means that repeats ON / OFF of the switching element within the ON permission period.

  Further, the operation means is not limited to the switching element of the lower arm, but may be the switching element of the upper arm. However, in this case, in the third and fourth embodiments, the presence or absence of disconnection is detected based on the presence or absence of inversion of the comparison signal of the phase in which the switching element of the lower arm is fixed in the ON state.

  The reference voltage vref is not limited to a virtual neutral point voltage (virtual neutral point voltage) generated based on the terminal voltages vu, vv, and vw, but may be a neutral point voltage of the brushless motor 10. Even in this case, the effect according to the first embodiment can be obtained. Further, even when the reference voltage vref is set to “½” of the voltage of the battery 14, by using the 3-bit composite signal and the 3-bit expectation signal, it is possible to accurately determine an abnormality in the rotation state, or 120 ° It is possible to improve the detection accuracy of the zero crossing timing during the energization control. Further, when the phase line on the inverter 12 side of the phase line of the brushless motor 10 is disconnected from the connection point with the resistors RU, RV, RW, etc., even if the neutral point voltage is used as the reference voltage vref, The disconnection can be detected by using the same phenomenon as in the third embodiment.

  The switching elements SW1, SW3, and SW5 on the upper side of the arm may be configured with N-channel MOS transistors.

  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 multi-phase rotating machine is not limited to a three-phase brushless motor, and may be a multi-phase motor. Furthermore, the generator is not limited to the electric motor. Even if the number of phases of the rotating machine is changed to N (> 3) in the third embodiment, only the single-phase switching element of the lower arm is in the on-permitted period during PWM control. The disconnection can be detected in the same manner as in the third embodiment. That is, when the single-phase switching element is shifted from the on-state to the off-state, the reference voltage vref is about “(N−1) · VB / N + Vf” when the threshold voltage Vf of the diode is used. Unless the number N becomes excessively large, it remains lower than the positive voltage VB of the battery 14. On the other hand, when there is no disconnection, the reference voltage vref becomes higher than the positive voltage VB of the battery 14 when the single-phase switching element is shifted from the on state to the off state. For this reason, it is possible to detect disconnection based on the presence or absence of logic inversion of the comparison signal of the phase corresponding to the switching element of the upper arm that is fixed in the ON state.

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 process sequence of operation of the switching element concerning the embodiment. The flowchart which shows the procedure of the switching process of the operation of the switching element concerning the embodiment. The flowchart which shows the process sequence of the PWM control concerning the embodiment. The time chart which shows the PWM control aspect concerning the embodiment. The time chart which shows the aspect of reverse rotation of a brushless motor. The flowchart which shows the procedure of the restart process of the brushless motor concerning 2nd Embodiment. The time chart for demonstrating the principle of the disconnection detection concerning 3rd Embodiment. The flowchart which shows the procedure of the disconnection detection process concerning the embodiment. The figure which shows the whole structure of the control system of the brushless motor concerning 4th Embodiment. The time chart which shows the conventional 120 degree electricity supply control aspect.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Brushless motor, 12 ... Inverter (one embodiment of a power converter circuit), 14 ... Battery (one embodiment of a power supply), 20 ... Control apparatus, SW1-SW6 ... Switching element.

Claims (7)

In order to control the multiphase rotating machine based on the zero cross timing at which the induced voltage of the multiphase rotating machine becomes a reference voltage, the positive and negative electrodes of the power source and the multiphase rotating machine are connected by a switching element , and In a control device for a multi-phase rotating machine that operates a power conversion circuit in which a rectifier is connected in parallel to each of switching elements ,
For each of the phases of the multiphase rotating machine , a comparison for comparing the magnitude relationship between the terminal voltage and the neutral point voltage of the multiphase rotating machine and a reference voltage set to one of its equivalent values. Means,
Information on the electrical angle of the multi-phase rotating machine based on the comparison for each phase of the comparison result by the comparison means assumed when the zero cross timing is reached in the current operation state of the switching element and the actual comparison result And obtaining means for obtaining
The acquisition means includes means for detecting the zero-crossing timing based on at least one phase match between the assumed comparison result and the actual comparison result,
Based on the zero cross timing, further comprising a setting means for setting a prescribed timing as a reference for switching the operation state of the switching element,
The specified timing and the zero-cross timing are associated with each other in a one-to-one relationship.
In the ON operation permission period of each switching element determined by the specified timing, further comprising an operation means for repeating ON / OFF of the switching element in the ON operation permission period,
In the period of treatment with the operating means is performed, the whether the comparison result of the comparison means indicates an inversion of the magnitude relationship for connected thereto phases of a switching element in the ON state are fixed among the switching elements A control device for a multiphase rotating machine, further comprising: a disconnection detecting means for detecting the presence or absence of disconnection of the phase line of the multiphase rotating machine. The acquisition means is based on the fact that the comparison result of the comparison means assumed when the zero cross timing is reached in the current operation state of the switching element and the actual comparison result are inconsistent in at least one phase. controller of the multi-phase rotary machine according to claim 1, characterized in that it comprises abnormality determination means for determining that there is an abnormality in the rotation state of phase rotation machine. The abnormality determination means is based on a match between an actual time series pattern and a time series pattern obtained by inverting the time series pattern of the comparison means assumed from the time series pattern of the operation state of the switching element with respect to time. 3. The control device for a multi-phase rotating machine according to claim 2 , further comprising means for determining that there is an abnormality in which the multi-phase rotating machine rotates reversely. When it is determined that there is an abnormality in the rotation state of the multi-phase rotating machine, stop means for forcibly stopping the rotation of the multi-phase rotating machine,
4. The control device for a multi-phase rotating machine according to claim 2 , further comprising start means for restarting the multi-phase rotating machine after the stopping process by the stopping means. 5. The multiphase according to claim 4 , wherein the stop means forcibly stops the rotation of the multiphase rotating machine by causing all phases of the multiphase rotating machine to conduct with either the positive electrode or the negative electrode. Control device for rotating machine. In a power conversion circuit including a switching element and a rectifying means connected in parallel to the switching element, a disconnection detecting device for a multiphase rotating machine that detects disconnection of a phase line of the multiphase rotating machine connected to the power converting circuit.
For each of the phases of the multiphase rotating machine, comparing means for comparing the magnitude relationship between the terminal voltage and the reference voltage consisting of either the neutral point voltage of the multiphase rotating machine or its equivalent value;
A single phase of the phases of the multiphase rotating machine is electrically connected to one of a pair of input terminals of the power conversion circuit, and at least one phase other than the single phase is the pair of inputs. Corresponding to the at least one phase when the switching element for turning on the one of the input terminals and the multiphase rotating machine is turned off in a state of being turned on with the other of the terminals. A disconnection detecting device for a multi-phase rotating machine, comprising: disconnection detecting means for detecting the presence or absence of the disconnection based on whether the comparison result of the comparison means indicates a reversal of the magnitude relationship . Setting means for setting a prescribed timing that is a reference for switching the operation state of the switching element based on a zero cross timing at which the induced voltage of the multiphase rotating machine matches the reference voltage;
Operation means for repeatedly turning on and off the switching element in the on-operation permission period in the on-operation permission period of each switching element determined by the specified timing when the phase current of the multiphase rotating machine is equal to or greater than a threshold value; Prepared,
The disconnection detection device according to claim 6 , wherein the disconnection detection unit performs the detection when processing by the operation unit is performed.

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