JP2013048524A - Control device of multi-phase rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a current from being generated at an inverter of a defective system or a winding set corresponding to it, for preventing overheating, relating to a control device equipped with inverters in two systems which controls driving of a multi-phase rotary machine containing two sets of windings.SOLUTION: A first system inverter 601 and a second system inverter 602 supply electric power to two sets of windings 801 and 802 constituting a motor 80 (multi-phase rotary machine) respectively. In a case where a first system failure detecting means 751 detects a short circuit failure of the inverter 601, a control part 65 stops output to the first system inverter 601. Relating to an output to the second system inverter 602 which is a normal system, the control part controls an output to be lower as rotational number N of the motor 80 that has been detected with a rotation angle sensor 85 increases. Thus, a current generated by a counter electromotive voltage is suppressed, thereby preventing overheating at a defective system (first system).

Description

  The present invention relates to a control device that controls driving of a multiphase rotating machine.

  Conventionally, as a driving device for a multi-phase rotating machine having a plurality of winding sets, there is one disclosed in Patent Document 1, for example. When a part of a plurality of inverters fails, this motor drive device stops power supply from the failed inverter to the plurality of winding sets, and from a normal inverter other than the failed inverter to the corresponding winding set. Supply power. Even if some inverters fail, the motor can be continuously operated by driving only with a normal inverter.

  In the control device for a multiphase rotating machine described in Patent Document 2, when a short-circuit failure occurs in one of the two systems of inverters or the corresponding winding set, the multiphase rotating machine is rotated. An object of the present invention is to suppress the brake torque generated by the generated back electromotive voltage. By controlling the brake torque so as to cancel out and driving an inverter of a normal system, pulsation of output torque of the multiphase rotating machine is reduced.

JP 2005-304119 A JP 2011-078230 A

By the way, even if the output to the power converter in the failed system is stopped, the multi-phase rotating machine is rotated by driving the power converter in the normal system or the multi-phase rotating machine is rotated from the load side. As a result, a back electromotive force is generated in the winding set of the fault system, and a current flows through the winding and the bridge circuit of the power converter. If the heat generated by this current becomes excessive, there is a risk of failure or damage of the element.
However, in the prior arts of Patent Documents 1 and 2, no consideration is given to dealing with heat generation due to a current generated in a power converter of a faulty system or a corresponding winding set.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a control device including two power converters for controlling driving of a multiphase rotating machine having two winding sets. It is to suppress the current generated in the power converter of the failed system or the corresponding winding set and prevent excessive heat generation.

The invention described in claim 1 is an invention relating to a control device for controlling the driving of a multi-phase rotating machine having two winding sets each composed of a plurality of phase windings.
This control device includes two systems of power converters, failure detection means, rotation speed detection means, and a control unit.
The two power converters are provided corresponding to the two winding sets and supply power to the two winding sets.
The failure detection means detects a failure in which a brake current flows through the multiphase rotating machine with respect to the power converter or the winding set.
The rotation speed detection means detects the rotation speed of the multiphase rotating machine.
The control unit controls the output to the power converter.
The control unit stops the output to the power converter of the fault system and detects the power of the normal system when a fault of the power converter of one system or the corresponding winding set is detected by the fault detection means. The output to the converter is limited so that the output is reduced as the rotation speed detected by the rotation speed detection means is higher.

Since the control unit stops the output to the power converter of the failed system, first, heat generated by the direct drive current in the failed system can be eliminated.
However, when the power converter in the normal system drives the multi-phase rotating machine or the multi-phase rotating machine is rotated from the load side, a back electromotive voltage is generated in the power converter in the failed system and current is generated. Flowing. This current increases as the rotational speed of the multiphase rotating machine increases.
Therefore, the control unit further controls the output to the power converter of the normal system so that the output becomes smaller as the rotational speed of the multiphase rotating machine is higher. Thereby, the electric current which generate | occur | produces with a counter electromotive voltage can be suppressed, and the excessive heat_generation | fever in a failure system | strain can be prevented.

  Here, a configuration that sets an “output limit value” that is an upper limit of the current command value is effective as a configuration that “limits the output to be reduced”. Further, as a relation pattern between the rotation speed and the output limit value, when the rotation speed is taken on the horizontal axis and the output limit value is taken on the vertical axis, (a) a pattern in which the negative slope is substantially constant and decreases substantially linearly, (B) A bent linear pattern in which the negative slope is zero or relatively small in a region where the rotational speed is equal to or less than a certain threshold, and the negative slope is relatively large when the rotational speed exceeds a certain threshold, (c) substantially inversely proportional Examples of shape patterns can be given.

  The invention described in claim 1 is based on the premise that there is a positive correlation between the rotational speed of the multiphase rotating machine and the current caused by the back electromotive force, and sets the output limit value based on the rotational speed. On the other hand, according to the second aspect of the present invention, an estimated current value based on the counter electromotive voltage is once calculated based on the rotational speed, and an output limit value is set from the estimated current value.

According to the second aspect of the present invention, the control unit has a current estimation unit. The current estimating means is a power converter for a fault system based on the number of revolutions detected by the speed detection means when a fault of the power converter for one of the systems or a corresponding winding set is detected by the fault detection means. Alternatively, the current value flowing through the corresponding winding set is estimated.
The current estimation means may calculate the current value by a predetermined calculation formula based on the rotation speed, or may estimate the current value by referring to a rotation speed-current map stored in advance.

And a control part restrict | limits the output to a power converter of a normal system | strain so that an output may become small, so that the electric current value which the electric current estimation means estimated is high.
Thereby, the current generated by the back electromotive voltage can be more accurately suppressed, and excessive heat generation in the fault system can be prevented.

The control device for a multi-phase rotating machine according to claim 3 includes a current detection means for detecting, for each system, a phase current that is supplied to the two winding sets from the two power converters, and the failure detection means includes: The failure is detected based on the current detection value detected by the current detection means.
Specific examples of the “failure in which a brake current flows in a multiphase rotating machine” according to claim 1 include a short-circuit failure of a switching element constituting the power converter, a winding power fault, a ground fault, and the like. In this case, a failure can be detected by detecting the phase current for each system.
As another example of detecting “a failure in which a brake current flows in a multiphase rotating machine”, an input voltage to the power converter may be detected for each system. Alternatively, the torque of the load driven by the multiphase rotating machine may be detected, and for example, a failure may be determined when a high-frequency torque ripple is detected.

  The invention according to claim 4 is an invention relating to the electric power steering apparatus. The electric power steering apparatus includes: a multi-phase rotating machine that generates assist torque for assisting a driver's steering; a control apparatus for a multi-phase rotating machine according to any one of claims 1 to 3; Power transmission means for transmitting the rotation of the phase rotating machine to the steering shaft.

  In an electric power steering device that assists the steering of a vehicle driver, the multi-phase rotating machine may be rotated from the load side when the driver steers the steering shaft. Therefore, with the configuration including the control device of the present invention, when a short circuit failure occurs in one system of the power converter, excessive heat generation in the failed system can be prevented.

The circuit schematic diagram of the 2 system | strain inverter controlled by the control apparatus of the multiphase rotary machine by one Embodiment of this invention. 1 is a schematic configuration diagram of an electric power steering device to which a control device for a multi-phase rotating machine according to an embodiment of the present invention is applied. The block diagram of the control apparatus of the multiphase rotating machine by one Embodiment of this invention. Explanatory drawing explaining the flow of the electric current at the time of a short circuit failure. (A), (b), (c): The figure which shows the example of a setting of the output limitation value with respect to an estimated current value (or rotation speed). (D): A characteristic diagram showing the relationship between the rotational speed and the estimated current value.

Hereinafter, an embodiment in which a control device for a multi-phase rotating machine according to the present invention is applied to an electric power steering device for a vehicle will be described with reference to the drawings.
(One embodiment)
A control device for a multi-phase rotating machine according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 2 shows an overall configuration of a steering system 90 including the electric power steering apparatus 1. A steering shaft 92 connected to the handle 91 is provided with a torque sensor 94 for detecting steering torque. A pinion gear 96 is provided at the tip of the steering shaft 92, and the pinion gear 96 meshes with the rack shaft 97. A pair of wheels 98 are rotatably connected to both ends of the rack shaft 97 via tie rods or the like. The rotational motion of the steering shaft 92 is converted into linear motion of the rack shaft 97 by the pinion gear 96, and the pair of wheels 98 are steered at an angle corresponding to the linear motion displacement of the rack shaft 97.

The electric power steering apparatus 1 includes an actuator 2 that rotates a rotation shaft, and a reduction gear 89 that reduces the rotation of the rotation shaft and transmits the rotation to the steering shaft 92.
The actuator 2 includes a motor 80 as a “multi-phase rotating machine” that generates a steering assist torque, and an ECU 10 as a “control device” that drives the motor 80. The motor 80 of this embodiment is a three-phase brushless motor, and rotates the reduction gear 89 forward and backward.
The ECU 10 includes a control unit 65 and an inverter 60 as a “power converter” that controls power supply to the motor 80 in accordance with a command from the control unit 65.

The rotation angle sensor 85 includes, for example, a magnet that is a magnetism generating unit provided on the motor 80 side and a magnetic detection element provided on the ECU 10 side.
The rotation angle sensor 85 detects the rotation angle θ of the motor 80 and also detects an angular velocity ω that is a change amount of the rotation angle θ per unit time. The angular velocity ω is also converted into the rotational speed N of the motor 80 from the relationship with the number of magnet pairs. That is, the rotation angle sensor 85 of the present embodiment is also a rotation speed sensor and corresponds to “rotation speed detection means” described in the claims.

  The control unit 65 controls output to the inverter 60 based on a rotation angle signal from the rotation angle sensor 85, a vehicle speed signal from a vehicle speed sensor (not shown), a steering torque signal from the torque sensor 94, and the like. Thus, the actuator 2 of the electric power steering apparatus 1 generates a steering assist torque for assisting the steering of the handle 91 and transmits the steering assist torque to the steering shaft 92.

  Specifically, as shown in FIG. 1, the motor 80 has two winding sets 801 and 802. The first winding set 801 includes U, V, and W phase three-phase windings 811 to 813, and the second winding set 802 includes U, V, and W phase three-phase windings 821 to 823. Is done. The inverter 60 includes a first system inverter 601 provided corresponding to the first winding set 801 and a second system inverter 602 provided corresponding to the second winding set 802. Here, the unit of the combination of the inverter and the three-phase winding set corresponding to the inverter is referred to as “system”.

  The ECU 10 includes a first system power relay 521, a second system power relay 522, a capacitor 53, a first system inverter 601, a second system inverter 602, a first system current detector 701, a second system current detector 702, and a control. Part 65 and the like. The current detectors 701 and 702 correspond to “current detection means” described in the claims, and detect the phase currents that the inverters 601 and 602 supply to the winding sets 801 and 802 for each system.

The battery 51 is, for example, a 12V DC power source. The power relays 521 and 522 can block power supply from the battery 51 to the inverters 601 and 602 for each system.
The capacitor 53 is connected in parallel with the battery 51, stores electric charge, assists power supply to the inverters 601 and 602, and suppresses noise components such as surge current.

  In the first system inverter 601, six switching elements 611 to 616 are bridge-connected to switch energization to the windings 811 to 813 of the first winding set 801. The switching elements 611 to 616 of this embodiment are MOSFETs (metal oxide semiconductor field effect transistors). Hereinafter, the switching elements 611 to 616 are referred to as MOSs 611 to 616.

The drains of high potential side MOSs (hereinafter referred to as “upper MOSs”) 611 to 613 are connected to the positive electrode side of the battery 51. The sources of the upper MOSs 611 to 613 are connected to the drains of the low potential side MOSs (hereinafter referred to as “lower MOSs”) 614 to 616. The sources of the lower MOSs 614 to 616 are connected to the negative electrode side of the battery 51 via current detection elements 711 to 713 constituting the current detector 701. Connection points of the upper MOSs 611 to 613 and the lower MOSs 614 to 616 are connected to one ends of the windings 811 to 813, respectively.
The current detection elements 711 to 713 detect phase currents that are supplied to the windings 811 to 813 of the first system U, V, and W phases, respectively.
Further, the input voltage Vr1 is detected by a predetermined voltage division between the power supply line of the first system inverter 601 and the ground line.

Regarding the second system inverter 602, the configuration of the switching elements (MOS) 621 to 626, the current detection elements 721 to 723 constituting the current detector 702, and the configuration for detecting the input voltage Vr2 are the same as those of the first system inverter 601. It is.
The control unit 65 includes a microcomputer 67, a drive circuit (predriver) 68, and the like. The microcomputer 67 controls and calculates each calculation value related to control based on input signals such as a torque signal and a rotation angle signal. The drive circuit is connected to the gates of the MOSs 611 to 616 and 621 to 626, and performs switching output based on the control of the microcomputer 67.

Next, a control block diagram of the ECU 10 is shown in FIG. In FIG. 3, the configuration of the control unit 65 (indicated by a two-dot chain line) in the ECU 10 will be described in detail.
For each of the first system and the second system, the control unit 65 includes current command value calculation means 151 and 152, three-phase two-phase conversion means 251, 252, controllers 301 and 302, two-phase three-phase conversion means 351 and 352. , And failure detection means 751 and 752. Further, the control unit 65 includes failure detection means 753 for detecting a failure based on a signal from the torque sensor 94.

The current command value calculation means 151 and 152 receive the signals of the rotation angle θ by the rotation angle sensor 85, the vehicle speed Vdc by the vehicle speed sensor, and the steering torque Tq ^* by the torque sensor 94, respectively. Based on these input signals, the current command value calculation means 151 calculates the d-axis current command value Id1 ^* and the q-axis current command value Iq1 ^* of the first system, and the current command value calculation means 152 The d-axis current command value Id2 ^* and the q-axis current command value Iq2 ^{* of the system} are calculated.
Here, the d-axis current command values Id1 ^* and Id2 ^* are current command values for the d-axis current (excitation current or field current) parallel to the direction of the magnetic flux, and the q-axis current command values Iq1 ^* and Iq2 ^*. Is a current command value for a q-axis current (torque current) orthogonal to the d-axis.

The output restriction means 201, 202 sets an output restriction value, which is the upper limit of the current command value, for a normal system that has not failed when a failure of any system is detected. The specific action relating to this output restriction will be described later.
When the current command values Id1 ^* and Iq1 ^* exceed the output limit value for the first system, the output limiting unit 201 corrects the current command value to a value equal to or less than the output limit value, and corrects the current command value Id1 ^** , Commands Iq1 ^** to the controller 301. On the other hand, when the current command values Id1 ^* and Iq1 ^* are equal to or less than the output limit value, the current command values Id1 ^* and Iq1 ^* are directly commanded to the controller 301 as the current command values Id1 ^** and Iq1 ^** . Similarly, when the current command values Id2 ^* and Iq2 ^* exceed the output limit value, the output limiting unit 202 corrects the current command value Id2 ^{* to} a value equal to or less than the output limit value when the current command values Id2 ^* and Iq2 ^* exceed the output limit value. ^** and Iq2 ^** are commanded to the controller 302. On the other hand, when the current command values Id2 ^* and Iq2 ^* are less than or equal to the output limit value, the current command values Id2 ^* and Iq2 ^* are directly commanded to the controller 302 as current command values Id2 ^** and Iq2 ^** .

Next, a configuration related to current feedback control executed for each system will be described.
For the first system, the three-phase to two-phase conversion means 251 determines the three-phase phase current detection values Iu1, Iv1, and Iw1 detected by the current detector 701 based on the rotation angle θ fed back from the rotation angle sensor 85 as d. The shaft current detection value Id1 and the q-axis current detection value Iq1 are converted.

The controller 301 receives a difference between the d-axis current correction command value Id1 ^** and the detected value Id1, and a difference between the q-axis current correction command value Iq1 ^** and the detected value Iq1. The controller 301 calculates the voltage command values Vd1 and Vq1 so that the difference converges to 0 (zero).
The controller 301 is, for example, PI (proportional integration) control calculation or the like, and calculates the voltage command values Vd1 and Vq1 based on the proportional gain and the integral gain.

Based on the rotation angle θ fed back from the rotation angle sensor 85, the two-phase / three-phase conversion means 351 converts the two-phase voltage command values Vd1 and Vq1 into the U-phase, V-phase, and W-phase three-phase voltage command values Vu1 and Vv1. , Vw1 and output to the first system inverter 601.
The inverter 601 supplies the phase currents Iu1, Iv1, Iw1 to the motor 80 according to the three-phase voltage command values Vu1, Vv1, Vw1, so that the current detection values Id1, Iq1 follow the current command values Id ^** , Iq ^** . try to.
Regarding the second system, the configuration of the three-phase / two-phase conversion means 252, the controller 302, and the two-phase / three-phase conversion means 352 is the same as that of the first system.

Next, the failure detection means 751, 752, and 753 will be described. The failure detection means 751 and 752 include, for each system, inverters 601 and 602 or winding sets 801 based on the phase current detection values detected by the current detectors 701 and 702 and the input voltages Vr1 and Vr2 of the inverters 601 and 602. “Failure in which a brake current flows through a multi-phase rotating machine due to a back electromotive force voltage” such as a short circuit failure 802, a short circuit of the capacitor 53, or a ground fault in the input to the inverter 601 is detected.
The short-circuit failure of the inverters 601 and 602 is one of the upper MOSs 611 to 613 and 621 to 623 or the lower MOSs 614 to 616 and 624 to 626 even though an off signal is input from the drive circuit 68 to the gate. First, it means a failure in which the MOS is turned on and the drain and source are electrically connected.

Further, the short failure of the winding sets 801 and 802 refers to a failure in which a winding of one phase and a power supply line are in a power fault, or a winding in one of the phases and a ground line are grounded.
Since the phase current detection value becomes an abnormal value in the case of these short-circuit faults, the fault detection means 751 and 752 detect the short-circuit fault because the phase current detection value is an abnormal value, and the short-circuit fault in any system Can be identified. Further, the failure detection means 753 determines that a short-circuit failure has occurred when a high-frequency torque ripple that cannot normally occur when one of the systems fails and only the remaining system continues to assist. To do.

  Next, the operation of the ECU 10 will be described. The ECU 10 supplies electric power to the two corresponding winding sets 801 and 802 from the two systems of inverters 601 and 602 whose outputs are controlled by the control unit 65, and drives the motor 80. Current detectors 701 and 702 detect phase current values supplied from the inverters 601 and 602 to the winding sets 801 and 802. The detected phase current values detected by the current detectors 701 and 702 are fed back to the control unit 65 and used to calculate voltage command values for the inverters 601 and 602.

Subsequently, a situation is assumed in which a short-circuit failure has occurred in either the inverter 601 or 602 or the winding set 801 or 802 in any one of the systems.
Here, it is assumed that the U-phase MOS of the inverter 601 of the first system is short-circuited and the second system is normal (see FIG. 3). Then, the first system failure detection means 751 detects that a short circuit failure has occurred in the first system based on the phase current detection values Iu1, Iv1, and Iw1 detected by the current detector 701.

When detecting a short-circuit failure, the failure detection means 751 sets the current command values Id1 ^* and Iq1 ^* commanded by the current command value calculation means 151 to stop the output to the failed first system inverter 601. Alternatively, the output limit value set by the output limiting unit 201 may be set to 0, and the corrected current command values Id1 ^** and Iq1 ^** may be set to 0. Alternatively, the power supply relay 521 provided on the power supply line of the inverter 601 may be cut off on the circuit, or all of the upper MOSs 611 to 613 and the lower MOSs 614 to 616 may be cut off.
As a result, the inverter 601 does not generate heat due to the direct drive current.

  However, when the second system inverter 602 which is a normal system drives the motor 80 or the motor 80 is rotated from the load side by the driver steering the steering shaft 92, the inverter 601 is reversed. An electromotive voltage is generated. Due to this counter electromotive voltage, a brake torque against the drive is generated in the motor 80. In addition, due to the counter electromotive voltage, a current flows through the first system inverter 601 to generate heat.

Here, with reference to FIG. 4, a description will be given of the principle that when a MOS short-circuits in one phase of the inverter bridge circuit, a current flows through the inverter in the fault system due to the back electromotive voltage.
As shown in FIG. 4, it is assumed that the first system U-phase upper MOS 611 has a short circuit failure. The V-phase upper MOS 612, the W-phase upper MOS 613, and the lower-phase MOSs 614 to 616 are normal. At this time, the current generated by the back electromotive voltage includes <1> V-phase and W-phase windings 812 and 813, <2> V-phase upper MOS 612, W-phase upper MOS 613 parasitic diode, and <3> short-circuited U It flows in the order of phase-up MOS 611 and <4> U-phase winding 811.

  Thus, the current flowing through the inverter 601 in the fault system increases as the rotational speed N of the motor 80 increases. Therefore, the control unit 65 prevents the inverter 601 from generating heat by limiting the output of the second system inverter 602, which is a normal system, according to the rotational speed N of the motor 80.

As a configuration relating to this output restriction, in this embodiment, current estimation means 401 and 402 are provided. When the first system short-circuit failure is detected by the failure detection means 751, the current estimation means 402 of the second system, which is a normal system, uses the current value Ib flowing to the failure system (first system) due to the back electromotive voltage as a motor. Estimate based on a rotational speed N of 80. Here, as shown in FIG. 5D, the rotational speed N and the estimated current value Ib have a positive correlation. The current estimation unit 402 may calculate a current value with a predetermined calculation formula based on the rotation speed N, or may estimate the current value Ib with reference to a rotation speed-current map stored in advance. Good.
Then, the current estimation unit 402 outputs the estimated current value Ib to the output limiting unit 202.

The output limiting means 202 sets the output limit value Ilim so that the output limit value Ilim decreases as the current estimated value Ib increases. FIGS. 5A to 5C show specific examples of the relationship pattern between the estimated current value Ib and the output limit value Ilim. In the present embodiment, the horizontal axis of FIGS. 5A to 5C is “current estimation value Ib”, and the vertical axis is “output limit value Ilim”.
FIG. 5A shows a “pattern in which the negative slope is substantially constant and monotonously decreases substantially linearly”. It is suitable for linearly suppressing heat generation with respect to the magnitude of the current flowing through the fault system. When the estimated current value Ib is equal to or greater than the maximum allowable value Ibmax, the output limit value Ilim is set to zero.

FIG. 5 (b) shows that “in the region where the estimated current value Ib is equal to or less than the threshold value Ibc, the negative slope is zero or relatively small, and when the estimated current value Ib exceeds the threshold value Ibc, the negative slope becomes relatively large. "Shape pattern". This is suitable when the influence on heat generation can be ignored in a small current region where the current estimation value Ib is equal to or less than the threshold value Ibc.
FIG. 5C shows a “substantially inversely proportional pattern”. Even if the current estimated value Ib increases, the output limit value Ilim is not set to 0, and is suitable, for example, when it is desired to maintain driving in the low torque high rotation region.

In addition, the output limiting unit 202 can adopt a suitable pattern according to the use environment and characteristics of the actuator 2.
Thus, the output limiting means 202 limits the output to the normal system inverter 602 by limiting the current command values Id2 ^* and Iq2 ^* by the output limiting value Ilim. Thereby, the electric current which generate | occur | produces with a counter electromotive voltage can be suppressed, and the excessive heat_generation | fever in a failure system (1st system) can be prevented.

  By the way, since the rotational speed N and the estimated current value Ib have a positive correlation, the output limiting means 202 can directly set the output limiting value Ilim based on the rotational speed N. However, in this embodiment, the current estimation unit 402 is provided, and after the current estimation value Ib is once estimated based on the rotation speed N, the output limiting unit 202 sets the output limit value Ilim based on the current estimation value Ib. To do. Thereby, the current generated by the back electromotive voltage can be more accurately suppressed, and excessive heat generation in the fault system can be prevented.

(Other embodiments)
(A) In other embodiments, as described above, the current estimating means 401 and 402 may not be provided, and the output limiting means 202 may directly set the output limiting value Ilim based on the rotational speed N. In this case, the horizontal axis of FIGS. 5A to 5C is treated as “the number of revolutions N”, and the relationship pattern between the number of revolutions N and the output limit value Ilim may be considered in the same manner as in the first embodiment.
Thereby, the structure of the control part 65 becomes simple.

(A) In the above embodiment, the phase relationship between the phase currents of the first system and the second system is not mentioned. As can be seen from the fact that the rotation angles fed back to the three-phase / two-phase conversion means 251 and 252 and the two-phase / three-phase conversion means 351 and 352 are both “θ” (see FIG. 3), in principle, the first system And the second system assume a current waveform in the same phase.
However, in another embodiment, for example, the phase currents Iu2, Iv2, and Iw2 of the second system are the same in amplitude and 30 ° out of phase with respect to the phase currents Iu1, Iv1, and Iw1 of the first system. It is good also as a structure. This is effective in reducing torque ripple (pulsation) of the motor 80.

(C) The specific configuration of the ECU 10 is not limited to the configuration of the above embodiment. For example, the switching element may be a field effect transistor other than a MOSFET, an IGBT, or the like.
(D) The number of phases of the multi-phase rotating machine is not limited to three phases, and may be four or more phases.
(E) The control device for a multiphase rotating machine according to the present invention is not limited to a motor control device for an electric power steering device, and may be applied as a control device for another multiphase motor or a generator.
As mentioned above, this invention is not limited to such embodiment, In the range which does not deviate from the meaning of invention, it can implement with a various form.

1 ... Electric power steering device,
2 ... Actuator 10 ... ECU (control device),
151, 152 ... current command value calculation means,
201, 202 ... Output limiting means,
401, 402 ... Current estimation means,
60, 601, 602... Inverter (power converter),
65 ・ ・ ・ Control unit,
701, 702 ... current detector (current detection means),
751, 752 ... Failure detection means,
80 ・ ・ ・ Motor (multi-phase rotating machine),
801, 802... Winding set,
85 ・ ・ ・ Rotational angle sensor (rotational speed detection means),
Id1 ^* , Id2 ^* ... d-axis current command value,
Iq1 ^* , Iq2 ^* ... q-axis current command value,
Ib ... current estimation value,
Ilim ... Output limit value.

Claims (4)

A control device for controlling the driving of a multi-phase rotating machine having two sets of windings composed of windings of a plurality of phases,
Two power converters provided corresponding to the two winding sets and supplying power to the two winding sets;
For the power converter or the winding set, failure detection means for detecting a failure in which a brake current flows in the multiphase rotating machine,
A rotational speed detection means for detecting the rotational speed of the multiphase rotating machine;
A control unit for controlling an output to the power converter;
With
The controller is
When the failure detection means detects a failure of the power converter of one of the systems or the corresponding winding set, the output to the power converter of the failed system is stopped, and the normal system of the power converter A control device for a multi-phase rotating machine, wherein the output to the power converter is limited so that the output is reduced as the rotational speed detected by the rotational speed detection means is higher. The controller is
When the failure detection means detects a failure of the power converter of one of the systems or the corresponding winding set, the power converter of the failure system based on the number of rotations detected by the rotation number detection means Or a current estimation means for estimating a current value flowing through the corresponding winding set,
2. The control device for a multi-phase rotating machine according to claim 1, wherein the output to the power converter of a normal system is limited so that the output becomes smaller as the current value estimated by the current estimation unit is higher. . A current detection means for detecting, for each system, a phase current that is passed through the two winding sets from the two power converters;
The control device for a multi-phase rotating machine according to claim 1, wherein the failure detection unit detects a failure based on a current detection value detected by the current detection unit. A multi-phase rotating machine that generates an assist torque for assisting the steering of the driver;
A control device for a multi-phase rotating machine according to any one of claims 1 to 3,
Power transmission means for transmitting rotation of the multiphase rotating machine to a steering shaft;
Electric power steering device with

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