JP2009165298A - Controller for multi-phase rotating machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the neutral point voltage of a brushless motor fluctuates largely, which causes noise, when driving the brushless motor by 120-degree energization process and PWM process. <P>SOLUTION: In the 120-degree energization process, respective ones of switching elements SW1, SW3 and SW5 of a high side arm and switching elements SW2, SW4 and SW6 of a low side arm of a power conversion circuit are turned on. In the PWM process, the switching elements of the power conversion circuit turn on/off so that two phases that are connected to the on-switching elements that are in the on-state are alternately made conductive to the high potential side input terminal and the low potential side input terminal of the power conversion circuit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for a multi-phase rotating machine that applies a voltage to the multi-phase rotating machine by operating a switching element of a power conversion circuit.

As this type of control device, for example, as shown in Patent Document 1 below, when a rectangular wave voltage is applied to a three-phase motor by a 120 ° energization method, the rectangular wave voltage is pulse-width modulated. Things have also been proposed. Here, the pulse width modulation is performed in synchronization with the switching timing of the switching for applying the rectangular wave voltage. As a result, it is possible to suppress noise when switching the arm that performs pulse width modulation.
JP-A-9-312993

  By the way, when the PWM process is performed in the above manner, the neutral point potential of the brushless motor 10 fluctuates in synchronization with the pulse width modulation. On the other hand, since the neutral point of an electric motor is generally arranged adjacent to a conductor via an insulator, the neutral point is equivalent to being grounded via a capacitor. Here, when the neutral point potential fluctuates in synchronization with the pulse width modulation, a current flows from the neutral point to the conductor side via the insulator, which may cause noise.

  The present invention has been made to solve the above-described problems, and its object is to operate the switching element of the power conversion circuit to suitably generate noise when applying a voltage to the multiphase rotating machine. An object of the present invention is to provide a control device for a multi-phase rotating machine that can be suppressed.

  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, the first phase of the multiphase rotating machine is conducted to the high potential side input terminal of the power conversion circuit and the second phase is conducted to the low potential side input terminal of the power conversion circuit. In the control device for a multi-phase rotating machine that applies a rectangular-wave voltage to the multi-phase rotating machine by operating the switching element of the power conversion circuit as described above, the rectangular wave-shaped voltage should be subjected to pulse width modulation. The first phase is electrically connected to the high potential side input terminal and the second phase is electrically connected to the low potential side input terminal, and the first phase is connected to the low potential side input terminal. It is characterized by comprising pulse width modulation means for operating the switching element so as to alternately switch the phase of the phase to the state of being electrically connected to the high potential side input terminal.

  In the above invention, when the first phase is conducted to the high potential side input terminal, the second phase is conducted to the low potential side input terminal, and when the first phase is conducted to the low potential side input terminal. The second phase is conducted to the high potential side input terminal, so that the neutral point voltage of the multiphase rotating machine during the pulse width modulation processing by the pulse width modulation means is substantially the same as when the pulse width modulation processing is not performed. Can be equal. For this reason, generation | occurrence | production of the noise at the time of a pulse width modulation process can be suppressed suitably.

  The rectangular-wave voltage is defined as “a substantially constant voltage applied over an angular region defined by a pair of rotation angles of a multiphase rotating machine”. More precisely, “the voltage applied when the voltage of the input terminal of the power conversion circuit is applied to the multi-phase rotating machine over an angle region defined by a pair of rotation angles of the multi-phase rotating machine. ""

  The switching element includes a high-potential side switching element for electrically connecting each phase of the multi-phase rotating machine to the high-potential side input terminal, and a phase for each phase of the multi-phase rotating machine to the low-potential side input terminal. And a low potential side switching element.

  According to a second aspect of the present invention, in the first aspect of the invention, there is provided means for detecting a rotation angle of the rotating machine using an induced voltage of the rotating machine.

  In the case of detecting the rotation angle of the rotating machine using the induced voltage, usually, the process of detecting the neutral point voltage of the rotating machine, the induced voltage appearing in the terminal voltage of the rotating machine and the reference voltage ( For example, “1/2” of the power supply voltage). Here, in the present invention, since the fluctuation of the neutral point voltage can be suitably suppressed by the pulse width modulation means, the influence of the fluctuation of the terminal voltage and the neutral point voltage is suitably removed when detecting the rotation angle. can do. For this reason, position sensorless driving can be easily performed.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the pulse width modulation processing by the pulse width modulation means limits at least one of the rotational speed, torque, and current of the multiphase rotating machine. When the request occurs, and when the request does not occur, the rectangular wave voltage is directly applied to the multiphase rotating machine.

  In the said invention, the neutral point voltage in the case of restrict | limiting the rotational speed of a multiphase rotary machine, a torque, and an electric current can be made substantially the same as the case where the voltage of a rectangular wave shape is applied.

  In the invention according to claim 4, a specific phase of the multi-phase rotating machine is set in a high impedance state in which neither a high-potential side input terminal nor a low-potential side input terminal of the power conversion circuit is conducted, and the remaining phases are In the control device for a multi-phase rotating machine that operates the switching element of the power conversion circuit to distribute the phase to be conducted to the potential side input terminal and the phase to be conducted to the low potential side input terminal, the remaining phase is set to the first phase. Operating the power conversion circuit so that the first phase and the second phase are alternately conducted to the high potential side input terminal and the low potential side input terminal. It is characterized by providing the means to do.

  In the above invention, when the first phase is conducted to the high potential side input terminal, the second phase is conducted to the low potential side input terminal, and when the first phase is conducted to the low potential side input terminal. In this case, the neutral point voltage before and after switching switching can be made substantially constant by conducting the second phase to the high potential side input terminal. For this reason, generation | occurrence | production of noise can be suppressed suitably.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the power conversion circuit connects each phase of the multiphase rotating machine to the high potential side input terminal. A high-potential side switching element, a rectifying means connected in parallel to the switching element and having a forward direction toward the high-potential side input terminal, and each of the phases are connected to the low-potential side input terminal And a rectifying unit that is connected in parallel to the low potential side switching element and has a forward direction toward the high potential side switching element.

  Instead of alternately conducting the first phase and the second phase to the high-potential side input terminal and the low-potential side input terminal, the switching element is turned on for one of the phases. When performing an off operation, the neutral point voltage largely fluctuates due to the current flowing through the rectifying means. For this reason, the applicability of the inventions of claims 1 to 4 is high.

  In addition, in the case where an element having the above-described invention-specific matters and allowing only a current flow in one direction from one of the pair of terminals to the other is used as the switching element, the element is in the on state. A current flows through the rectifying means connected in parallel to the switching element through which no current flows. And thereby, the fluctuation | variation of a neutral point voltage can be suppressed.

  A sixth aspect of the invention is characterized in that, in the invention according to any one of the first to fifth aspects, the switching element allows a current to flow in both directions.

  In the said invention, an electric current can be sent through the switching element made into an ON state so that a 1st phase and a 2nd phase may be alternately conducted to a high potential side input terminal and a low potential side input terminal. In particular, an element that allows current to flow in both directions tends to have a lower conduction resistance than the rectifying means. Thus, current can be passed through the switching element without passing current. For this reason, compared with the case where an electric current is sent through a rectification | straightening means, a power loss can be reduced.

  Hereinafter, an 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 having a permanent magnet as a rotor, and is an actuator of a fuel pump of an internal combustion engine mounted on a vehicle. 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 includes a parallel connection body of the switching elements SW1, SW2, the switching elements SW3, SW4, and the switching elements SW5, SW6 so that each of the three phases and the positive electrode side or the negative electrode side of the battery 14 are electrically connected. It is prepared for. 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 this embodiment, the switching elements SW1, SW3, and SW5 in the upper arm are configured by P-channel MOS field effect transistors, and the switching elements SW2, SW4, and SW6 in the lower arm are N-channel MOS field effect transistors. A transistor is used. The flywheel diodes D1 to D6 are configured as parasitic diodes of the MOS field effect transistor.

  The control device 20 operates the inverter 12 with the brushless motor 10 as a control target. Here, basically, switching control is performed by a 120 ° energization method. This process uses the timing at which the induced voltage appears in the terminal voltages vu, vv, and vw of each phase of the brushless motor 10 by the zero-cross detection unit 20a in the control device 20, and the induced voltage is the neutral point of the brushless motor 10. This is performed based on the detection of the timing (zero cross timing) at which the voltage (reference voltage vref) is reached. Here, in the present embodiment, it is assumed that the reference voltage vref is divided from the terminal voltages vu, vv, vw of each phase of the brushless motor 10 by the resistors RU, RV, RW. Specifically, it is assumed that the divided pressure is filtered by the filter 22. The zero cross timing is the inversion timing of the outputs of the comparators 24, 26, and 28 for comparing the magnitude relationship between the terminal voltages vu, vv, and vw of each phase and the reference voltage vref. 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. The control device 20 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. 2A1 to FIG. 2F1 show the transition of the switching operation mode of the switching elements SW1 to SW6 during the 120 ° energization process. Specifically, FIG. 2 (a1) shows the transition of the operation signal of the switching element SW1, FIG. 2 (b1) shows the transition of the operation signal of the switching element SW3, and FIG. 2 (c1) shows the transition of the switching element SW5. FIG. 2 (d1) shows the transition of the operation signal of the switching element SW2, FIG. 2 (e1) shows the transition of the operation signal of the switching element SW4, and FIG. 2 (f1) shows the transition of the operation signal. The transition of the operation signal of the switching element SW6 is shown.

  As shown in the figure, each of the switching elements SW <b> 1 to SW <b> 6 is turned on once in one rotation of the brushless motor 10 for a period equal to each other. Specifically, since the switching elements SW1, SW3, and SW5 of the upper arm are sequentially turned on by “120 °”, the ON periods of the switching elements SW1, SW3, and SW5 do not overlap each other. . Further, since the switching elements SW2, SW4, SW6 of the lower arm are also sequentially turned on by “120 °”, the ON periods of these switching elements SW2, SW4, SW6 do not overlap each other. Absent.

  When the current flowing through the brushless motor 10 exceeds the current limit value, the control device 20 performs PWM control to limit the current flowing through the brushless motor 10 (energization amount). Similarly, PWM control is performed when the torque and rotation speed of the brushless motor 10 are limited. By performing PWM control, the energization amount of the brushless motor 10 is reduced as compared with the 120 ° energization process, so that the current can be limited, and the torque and rotation speed can be limited. FIGS. 2A2 to 2F2 show switching modes of the switching elements SW1 to SW6 during PWM control according to the present embodiment. 2A2 to FIG. 2F2 correspond to FIGS. 2A1 to 2F1, respectively.

  As shown in the figure, in this embodiment, two phases connected to a switching element that is turned on by a 120 ° energization process are connected to a high potential side input terminal of the inverter 12 (positive electrode of the battery 14) and a low potential side input. The terminal (the negative electrode of the battery 14) is alternately conducted. In other words, for each of the above two phases, the switching elements SW1, SW3, SW5 of the upper arm and the switching elements SW2, SW4, SW6 of the lower arm are alternately turned on, and one of the two phases is on the upper side. When the arm is turned on, the other is turned on on the lower arm. Thereby, suppression of the fluctuation | variation of the neutral point electric potential of the brushless motor 10 is aimed at. Hereinafter, this will be described with reference to FIG.

  In FIG. 3A, among the cases where the switching state is the same as that of the 120 ° energization method during PWM control, in particular, the switching element SW1 of the U-phase upper arm and the switching element SW4 of the V-phase lower arm The case where is in the on state is illustrated. In this case, the U-phase terminal voltage vu is the voltage VB of the battery 14 (more precisely, a value about the amount of voltage drop between the source and drain of the switching element SW1). Further, the V-phase terminal voltage vv becomes the ground potential GND (more precisely, a value that is higher by about the amount of voltage drop between the source and drain of the switching element SW4). Here, the remaining one-phase W phase is in a high impedance state because the switching elements SW5 and SW6 of both the upper arm and the lower arm are turned off. For this reason, the neutral point voltage of the brushless motor 10 is about “VB / 2” if the influence of the induced voltage is ignored.

  FIG. 3B shows a case where the switching state is switched from the state of FIG. 3A by PWM control. Since current has flowed into the U-phase before this switching, an electromotive force is generated by the inductor component of the brushless motor 10 to cause a current in the same direction to flow even after switching. For this reason, a current flows from the switching element SW2 of the lower arm of the U phase that is newly turned on to the U phase. At this time, the current does not flow through the diode D2 connected in parallel to this, because the voltage drop amount between the source and drain of the switching element is smaller than the voltage drop amount of the diode. On the other hand, in the state of FIG. 3A, since the current flows out from the V phase, an electromotive force is generated by the inductor component of the brushless motor 10 so as to flow the current in the same direction even after switching. For this reason, a current flows from the V phase of the brushless motor 10 to the switching element SW3 of the upper arm of the V phase that is newly turned on. At this time, the current does not flow through the diode D3 connected in parallel because the voltage drop amount between the source and drain of the switching element is smaller than the voltage drop amount of the diode.

  In the state shown in FIG. 3B, the U-phase terminal voltage vu becomes the ground potential GND (more precisely, a value that is lower by about the amount of voltage drop between the source and drain of the switching element SW4). . Further, the V-phase terminal voltage vv is the voltage VB of the battery 14 (more precisely, a value about the amount of voltage drop between the source and drain of the switching element SW1). The remaining one-phase W phase is in a high impedance state because the switching elements SW5 and SW6 of both the upper arm and the lower arm are turned off. For this reason, the neutral point voltage of the brushless motor 10 is about “VB / 2” if the influence of the induced voltage is ignored. That is, the neutral point voltage hardly changes before and after switching between FIGS. 3 (a) and 3 (b). For this reason, it is possible to perform PWM processing while suitably suppressing fluctuations in the neutral point voltage.

  FIG. 4 shows the result of the PWM processing. Specifically, FIG. 4A shows the transition of the terminal voltage in this case, FIG. 4B shows the transition of the phase current, FIG. 4C shows the transition of the neutral point potential, FIG. 4D shows the transition of the voltage spectrum.

  As shown in FIG. 4C, the neutral point voltage basically only changes smoothly according to the induced voltage. Therefore, it is possible to easily detect the zero cross timing at which the neutral point voltage becomes the reference voltage vref. Specifically, in this embodiment, the reference voltage vref can be stabilized only by using a filter having a sufficiently small time constant as the filter 22 shown in FIG. For this reason, the zero cross detection part 20a can be made into a simple structure. Furthermore, as shown in FIG. 4D, the noise level is also kept small. Therefore, during PWM control, it is possible to suitably avoid a situation in which an alternating current flows to a conductor adjacent to the neutral point of the brushless motor 10 via an insulator, and thus to appropriately suppress or avoid common mode noise. Can do.

  On the other hand, FIG. 5 shows a case where normal PWM processing is performed, that is, a case where a switching element that is turned on in 120 ° energization processing is turned on / off. 5A to 5D correspond to FIGS. 4A to 4D.

  As shown in FIG. 5C, in this case, the neutral point voltage greatly fluctuates. For this reason, in order to detect the zero-cross timing, the processing for detecting the zero-cross timing becomes complicated, for example, the processing for prohibiting the detection of the zero-cross timing is performed during the voltage fluctuation period associated with the switching. Further, as shown in FIG. 5 (d), the noise becomes large. For this reason, by performing PWM control, an alternating current flows to a conductor adjacent to the neutral point of the brushless motor 10 via an insulator, and common mode noise is generated in the vehicle.

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

  (1) During 120 ° energization processing, the first phase connected to the high potential side input terminal (the positive side of the battery 14) of the inverter 12 and the second phase connected to the low potential side input terminal (the negative side of the battery 14). The PWM control was performed by alternately conducting the phase of 1 to the high potential side input terminal and the low potential side input terminal. Thereby, generation | occurrence | production of the noise at the time of PWM control can be suppressed suitably.

  (2) A sensorless method is used in which the required time from the zero cross timing at which the induced voltage of the brushless motor 10 becomes the reference voltage vref to the switching timing of the operation state of the switching element by the 120 ° energization process is calculated based on the zero cross timing interval. In this case, if the neutral point voltage fluctuates greatly, it is necessary to detect the zero cross timing while masking the fluctuation, but such a problem does not occur according to the PWM control according to the present embodiment. For this reason, the brushless motor 10 can be driven by a sensorless system with a simple process.

  (3) In a normal state, a rectangular wave voltage is applied to the brushless motor 10 with an angular interval obtained by equally dividing one rotation angle of the brushless motor 10 in all phases and without overlapping each other in each phase. The 120 ° energization method was adopted. Thereby, a neutral point voltage can be stabilized more suitably.

  (4) As the switching elements SW1 to SW6, those in which a pair of terminals (source and drain) flow current bidirectionally are employed. As a result, during PWM control, a current in the direction opposite to the current flow direction during the 120 ° energization process flows through the switching elements SW1 to SW6. Therefore, compared with the case where this current flows through the diodes D1 to D6, Loss can be reduced.

(Other embodiments)
The above embodiment may be modified as follows.

  The application of the rectangular wave voltage to the brushless motor 10 is not limited to the 120 ° energization method. For example, a 130 ° energization method in which the switching elements SW1 to SW6 of each phase are turned on by 130 ° may be used. In this case, in each arm, there is an overlap period in which the switching elements SW1, SW3, SW5 (switching elements SW2, SW4, SW6) of the plurality of phases are simultaneously turned on. Therefore, the PWM control is performed as described in the above embodiment. Even if is performed, the neutral point potential is not as constant as in the above embodiment. However, even in this case, the inventors have found that there is an effect of reducing noise.

  FIGS. 6A to 6D show cases corresponding to the previous FIGS. 4A to 4D when PWM control is performed based on the 130 ° energization process. As can be seen from FIG. 6D and the like, even in this case, the noise is suitably reduced. On the other hand, FIG. 7 shows a case where the conventional PWM control is performed based on the 130 ° energization method. Here, FIGS. 7A to 7D correspond to FIGS. 6A to 6D described above. As shown in the figure, the noise is increased as compared with the case shown in FIG. Incidentally, in the example shown in FIG. 6, during the overlap period, the phase in which the upper arm is turned on and the phase in which the lower arm is turned on according to the 130 ° energization control are alternately input on the high potential side. It is electrically connected to the terminal and the low potential side input terminal.

  -The energization control when PWM control is not performed is not limited to 120 ° energization control or 130 ° energization control, but a control method with an energization angle narrower than 120 ° or a control method with an energization angle wider than 130 °. There may be. At this time, it is desirable that the energization angle control method is “120 ° ± 30 °”. In other words, the rectangular wave voltage applied to the brushless motor 10 is desirably a voltage of “120 ° ± 30 °”.

  In the above-described embodiment, the case where the pulse width modulation is performed over the entire application period of the rectangular wave voltage is illustrated, but the present invention is not limited thereto. For example, for the purpose of instantaneous torque control or the like, pulse width modulation may be performed only at the end of a rectangular wave voltage.

  In the above embodiment, the terminal voltages vu, vv, vw and the reference voltage vref may be compared by microcomputer processing instead of the comparators 24, 26, 28.

  Instead of using the reference voltage vref as the virtual neutral point voltage, the neutral point voltage of the brushless motor 10 or a voltage corresponding to “½” of the power supply voltage may be used.

  The means for detecting the rotation angle using the induced voltage of the brushless motor 10 is not limited to detecting zero cross timing based on the induced voltage. For example, the induced voltage that appears in the terminal voltage of the brushless motor 10 may be compared with “½” of the voltage of the battery 14. For example, as can be seen in Japanese Patent Application Laid-Open No. 11-18478, a timing at which a predetermined electrical angle other than the zero cross timing is detected based on the induced voltage may be detected. Even in such a case, the sensorless process can be easily performed by using the method of the present invention that can suppress the fluctuation of the neutral point voltage or the virtual neutral point voltage of the brushless motor 10.

  -It is not restricted to the sensorless system which acquires the rotation angle information of the brushless motor 10 based on an induced voltage, and operates switching element SW1-SW6 based on this. For example, even in a device provided with a rotation angle detection means such as a Hall element, the application of the present invention is effective in reducing noise associated with PWM processing.

  The upper arm switching elements SW1, SW3, and SW5 may be N-channel MOS field effect transistors.

  -Switching elements that allow current to flow in both directions are not limited to MOS field-effect transistors. For example, it may be a MIS field effect transistor or the like. Furthermore, it is not limited to a field effect transistor.

  The switching elements SW1 to SW6 are not limited to those in which a pair of terminals (drain and source) flow current bidirectionally, and may be, for example, insulated gate bipolar transistors (IGBT).

  The power source connected to the brushless motor 10 is not limited to the battery 14 but may be a general DC power source such as a direct current generated by means such as rectification from a generator or an alternating current power source.

  The brushless motor 10 is not limited to an on-vehicle fuel pump actuator, and may be, for example, an on-vehicle cooling fan motor. Further, for example, it may be a motor for household appliances such as a refrigerator and a washing machine.

  -The rotating machine is not limited to a three-phase brushless motor, and may be a multi-phase electric motor. Furthermore, the generator is not limited to the electric motor.

The system block diagram concerning one Embodiment. The time chart which shows the switching control aspect concerning the embodiment. The circuit diagram for demonstrating the merit of the PWM process concerning the embodiment. The time chart which shows the simulation result of the PWM process concerning the embodiment. The time chart which shows the simulation result of the conventional PWM process. The time chart which shows the simulation result of the PWM process in the modification of the said embodiment. The time chart which shows the simulation result of the PWM process based on the conventional 130 degree electricity supply process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Brushless motor, 12 ... Inverter, 14 ... Battery, 20 ... Control apparatus, SW1-SW6 ... Switching element.

Claims (6)

Switching the power conversion circuit so that the first phase of the multi-phase rotating machine is conducted to the high potential side input terminal of the power conversion circuit and the second phase is conducted to the low potential side input terminal of the power conversion circuit. In the control device for a multiphase rotating machine that applies a rectangular wave voltage to the multiphase rotating machine by operating the element,
A state in which the first phase is electrically connected to the high-potential side input terminal and the second phase is electrically connected to the low-potential side input terminal, respectively, in order to perform pulse width modulation on the rectangular wave-shaped voltage; Pulse width modulation means for operating the switching element to alternately switch between a state in which the phase is conducted to the low potential side input terminal and a state in which the second phase is conducted to the high potential side input terminal. Control device for multi-phase rotating machines.   The control device for a multi-phase rotating machine according to claim 1, further comprising means for detecting a rotation angle of the rotating machine using an induced voltage of the rotating machine.   The pulse width modulation processing by the pulse width modulation means is performed when a request to limit at least one of the rotational speed, torque, and current of the multiphase rotating machine occurs, and when the request does not occur, the multiple 3. The control device for a multi-phase rotating machine according to claim 1, wherein the rectangular-wave voltage is directly applied to the phase rotating machine. A phase in which a specific phase of the multi-phase rotating machine is in a high impedance state in which neither a high-potential side input terminal nor a low-potential side input terminal of the power conversion circuit is conducted, and the remaining phase is conducted to the high-potential side input terminal. And a control device for a multi-phase rotating machine that operates a switching element of the power conversion circuit in order to distribute to a phase to be conducted to the low potential side input terminal,
The remaining phase is divided into a first phase and a second phase, and the first phase and the second phase are alternately conducted to the high potential side input terminal and the low potential side input terminal. A control device for a multi-phase rotating machine, further comprising means for operating the power conversion circuit.   The power conversion circuit includes a high-potential side switching element that connects each phase of the multiphase rotating machine to the high-potential side input terminal, and is connected in parallel to the switching element and to the high-potential side input terminal side. Rectifying means having a forward direction as a forward direction, a low-potential-side switching element that connects each of the phases to the low-potential-side input terminal, a parallel connection to the switching element, and the high-potential-side switching element side The control device for a multi-phase rotating machine according to any one of claims 1 to 4, further comprising a rectifier that sets a forward direction to a forward direction.   The control device for a multiphase rotating machine according to any one of claims 1 to 5, wherein the switching element is configured to flow a current in both directions.

Images