Control device for a rotating electric machine and electric power steering device

Abstract

Provided are a control device of a rotating electric machine and an electric power steering device, which can reduce an error of an alternating component included in a sensor detection value of a rotation angle at a high rotation speed, and suppress an increase in a rotation angle error caused by a high-frequency noise component included in a current detection value. A deviation of a control rotation angle (θc) with respect to a true rotation angle, that is, a predicted actual angle deviation (Δθe), is calculated, a deviation of the control rotation angle (θc) with respect to a detection value (θd) of the rotation angle, that is, a detection angle deviation (Δθd), is calculated, the predicted actual angle deviation (Δθe) and the detection angle deviation (Δθd) are divided by each other, a control angle deviation (Δθc) is calculated, feedback control is performed so that the control angle deviation (Δθc) approaches 0, and the control rotation angle (θc) is calculated. When the rotation speed is higher than a speed threshold value, a ratio (Ke) of the predicted actual angle deviation is set to be higher than a ratio (Kd) of the detection angle deviation.

Description

TECHNICAL FIELD

[0001] The present application relates to a control device for a rotary electric machine and an electric power steering device. BACKGROUND

[0002] In order to control a rotary electric machine in which magnets are provided on a rotor, it is necessary to detect the rotation angle of the rotor. There is an error between the rotation angle detected by the rotation sensor and the true rotation angle. The direct current component of the sensor angle error is an error in the direct current component of the torque, and the alternating current component of the sensor angle error is an error in the alternating current component of the torque (torque ripple error). The torque ripple error becomes a major cause of noise from the rotary electric machine. Therefore, in order to rotate the rotary electric machine in a quiet state, it is important to reduce the alternating current component of the angle error.

[0003] The technology of Patent Literature 1 estimates the shaft error Δθdc by the shaft error calculator 605, calculates the corrected electrical angular velocity ω1c by adding the correction amount Δω1c that controls the shaft error Δθdc to 0 to the electrical angular velocity ω1sc detected by the normal rotation position sensor, and calculates the rotor phase θdc on the basis of the electrical angular velocity ω1c.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Laid-Open No. 2019-050684 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, in the technology of Patent Literature 1, the correction amount Δω1c that makes the estimated shaft error Δθdc 0 is added to the electrical angular velocity ω1sc detected by the normal rotation position sensor, and therefore, in the case where an error of an alternating component is included in the electrical angular velocity ω1sc, the shaft error Δθdc and the correction amount Δω1c need to respond at the frequency of the alternating component in order to compensate for the error of the alternating component. The frequency of the alternating component is proportional to the rotation frequency, and therefore, as the rotation speed increases, the frequency of the alternating component also increases. In order to make the correction amount Δω1c respond at the rotation frequency at a high rotation speed, it is necessary to increase the response frequency of the feedback control that calculates the correction amount Δω1c to the maximum rotation frequency. If the response frequency of the feedback control is increased, noise components are also superimposed on the correction amount Δω1c in response to high-frequency noise components included in the current detection value used to calculate the shaft error Δθdc. That is, in the technology of Patent Literature 1, at a high rotation speed, the reduction of the error of the alternating component included in the sensor detection value of the rotation angle and the increase of the error due to the noise components included in the current detection value become in a trade-off relationship, and it is difficult to detect the rotation angle with high precision.

[0009] Therefore, an object of the present application is to provide a control device of a rotating electric machine and an electric power steering device that can reduce an error of an alternating component included in a sensor detection value of a rotation angle at a high rotation speed while suppressing an increase of a rotation angle error caused by high-frequency noise components included in a current detection value.

[0010] Technical means for solving the technical problem

[0011] A control device of a rotating electric machine according to the present application controls a rotating electric machine having a stator provided with a multiphase winding and a rotor provided with a magnet via a power converter, and includes:

[0012] a rotation detection section that detects a rotation angle of the rotor on the basis of an output signal of a rotation sensor;

[0013] a control angle calculation section that calculates a control rotation angle of the rotor;

[0014] a current detection section that detects a current flowing through the multiphase winding on the basis of an output signal of a current sensor;

[0015] a voltage command value calculation section that calculates a voltage command value applied to the multiphase winding on the basis of the control rotation angle and a current detection value; and

[0016] a switch control section that turns on and off a plurality of switching elements included in the power converter on the basis of the voltage command value,

[0017] In the control angle calculation section,

[0018] Based on information of the current detection value and information of the voltage command value, a presumed actual angle deviation is presumed, the presumed actual angle deviation being a deviation of the control rotation angle from a true rotation angle of the rotor,

[0019] A detection angle deviation is calculated, the detection angle deviation being a deviation of the control rotation angle from a detection value of the rotation angle,

[0020] A value obtained by dividing the presumed actual angle deviation and the detection angle deviation is calculated as a control angle deviation,

[0021] The control rotation angle is calculated by performing feedback control so that the control angle deviation approaches 0,

[0022] In a case where a speed proportional physical quantity, which is a physical quantity proportional to a rotation speed of the rotor, is higher than a speed threshold value set in advance, a proportion of the presumed actual angle deviation in the control angle deviation is set higher than a proportion of the detection angle deviation,

[0023] In a case where the speed proportional physical quantity is lower than the speed threshold value, the proportion of the presumed actual angle deviation in the control angle deviation is set lower than the proportion of the detection angle deviation.

[0024] The electric power steering apparatus according to the present application includes:

[0025] The control device of the rotary electric machine described above;

[0026] The power converter;

[0027] The rotary electric machine; and

[0028] A drive force transmission mechanism that transmits a drive force of the rotary electric machine to a steering device of a vehicle,

[0029] A response frequency from the control angle deviation to the control rotation angle is set to 90 Hz or more.

[0030] Effects of the Invention

[0031] According to the control device of a rotating electric machine and the electric power steering device according to the present application, the rotational angle for control is calculated by feedback control to make the control angle deviation, which is obtained by dividing the estimated actual angle deviation and the detected angle deviation, close to 0, and thus the sensor detection value of the rotational angle is not corrected using the feedback control value as in Patent Document 1, and it is not necessary to increase the response frequency of the feedback control to reduce the error of the alternating component included in the sensor detection value of the rotational angle at high rotational speed. Therefore, the response frequency of the feedback control can be set to a frequency that can respond to the vibration frequency of the mechanical rotational angle of a relatively low frequency, and set to a frequency that does not respond to the noise component of the current detection value of a relatively high frequency. Further, at high rotational speed, since the proportion of the estimated actual angle deviation is higher than the proportion of the detected angle deviation, and the rotational angle for control is calculated by feedback control to make the control angle deviation close to 0, it is possible to suppress the case where the error of the alternating component included in the sensor detection value of the rotational angle is reflected in the rotational angle for control, and it is possible to make the rotational angle for control close to the true rotational angle. Therefore, at high rotational speed, it is possible to reduce the error of the alternating component included in the sensor detection value of the rotational angle, while suppressing the increase in the error of the rotational angle caused by the noise component of a high frequency included in the current detection value. Further, at low rotational speed, even in the case where the proportion of the detected angle deviation is higher than the proportion of the estimated actual angle deviation, since the rotational angle for control is calculated by feedback control to make the control angle deviation close to 0, it is possible to suppress the case where the error of the alternating component included in the sensor detection value of the rotational angle is reflected in the rotational angle for control. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a brief configuration diagram of the rotating electric machine, the power converter, and the control device according to Embodiment 1.

[0033] Figure 2 is a brief block diagram of the control device according to Embodiment 1.

[0034] Figure 3 is a hardware configuration diagram of the control device according to Embodiment 1.

[0035] Figure 4 is a diagram for explaining the control region according to Embodiment 1.

[0036] Figure 5 is a diagram for explaining the control region according to Embodiment 1.

[0037] Figure 6 is a block diagram of the control angle calculation section according to Embodiment 1.

[0038] Figure 7is a graph showing the setting of the internal ratio involved in Embodiment 1.

[0039] Figure 8 is a Bode chart showing the response frequency in Embodiment 1.

[0040] Figure 9 is a block diagram of the control angle calculation section involved in Embodiment 2. DETAILED DESCRIPTION

[0041] 1. Embodiment 1

[0042] A control device 10 (hereinafter simply referred to as control device 10) involved in Embodiment 1 will be described with reference to the accompanying drawings. Figure 1 is a brief configuration diagram of a rotary electric machine 1, a power converter 4, and the control device 10 involved in the present embodiment. In the present embodiment, the rotary electric machine 1 becomes a driving force source of an electric power steering device 100, and the rotary electric machine 1, the power converter 4, and the control device 10 constitute the electric power steering device 100.

[0043] 1-1. Rotary electric machine 1

[0044] The rotary electric machine 1 includes a stator and a rotor arranged on the radially inner side of the stator. A multiphase winding (three-phase winding Cu, Cv, Cw of U phase, V phase, W phase in the present example) is provided in the stator. A magnet is provided in the rotor. In the present embodiment, the magnet is a permanent magnet, and the rotary electric machine 1 is provided as a synchronous rotary electric machine of the permanent magnet type. In addition, the magnet can be an electromagnet having a field winding. The three-phase winding can be star-connected or delta-connected.

[0045] The rotor includes a rotation sensor 2 for detecting the rotation angle of the rotor. The rotation sensor 2 uses a resolver, an encoder, an MR sensor, or the like. The output signal of the rotation sensor 2 is input to the control device 10.

[0046] 1-2. Power converter 4

[0047] An inverter is used as the power converter 4. In addition, as the power converter 4, a power converter other than the inverter, such as a matrix converter, can also be used.

[0048] The inverter 4 is provided with 3 sets of series circuits (branches) corresponding to each of the three phases, and a positive-side switching element SP connected to the positive side of the direct-current power supply 3 and a negative-side switching element SN connected to the negative side of the direct-current power supply 3 are connected in series in the series circuit. Then, the connection points of the two switching elements in the series circuit of each phase are connected to the winding of the corresponding phase.

[0049] Specifically, in the series circuit of the U phase, the switching element SPu on the positive side of the U phase and the switching element SNu on the negative side of the U phase are connected in series, and the connection point of the two switching elements is connected to the U phase winding Cu. In the series circuit of the V phase, the switching element SPv on the positive side of the V phase and the switching element SNv on the negative side of the V phase are connected in series, and the connection point of the two switching elements is connected to the V phase winding Cv. In the series circuit of the W phase, the switching element SPw on the positive side of the W phase and the switching element SNw on the negative side of the W phase are connected in series, and the connection point of the two switching elements is connected to the W phase winding Cw. The smoothing capacitor 5 is connected between the positive side and the negative side of the direct current power supply 3.

[0050] For the switching elements, IGBT (Insulated Gate Bipolar Transistor) connected in reverse parallel with a diode, MOSFET (Metal Oxide Semiconductor Field Effect Transistor), bipolar transistor connected in reverse parallel with a diode, or the like is used. The gate terminal of each switching element is connected to the control device 10 via a gate drive circuit or the like. Each switching element is turned on or off by a switching signal GPu to GNw output from the control device 10.

[0051] The direct current power supply 3 outputs a direct current voltage Vdc to the inverter 4. In the present embodiment, the direct current voltage Vdc is set to 12 V. As the direct current power supply 3, any device that outputs the direct current voltage Vdc, such as a battery, a DC-DC converter, a diode rectifier, a PWM rectifier, or the like, can be used. The direct current power supply 3 is provided with a voltage sensor that detects the direct current voltage Vdc, and the output signal of the voltage sensor can be input to the control device 10. The control device 10 can perform control using the detected direct current voltage Vdc.

[0052] A current sensor 6 that detects the current flowing through each phase winding is provided. The current sensor 6 is configured as a shunt resistor or a current sensor such as a Hall element. The output signal of the current sensor 6 is input to the control device 10.

[0053] In the present embodiment, the current sensor 6 is also provided on the series circuit of the two switching elements of each phase. The U phase resistor Ru, the V phase resistor Rv, and the W phase resistor Rw are connected in series to the negative side of the switching element SN on the negative side of each phase. The three-phase resistors Ru, Rv, and Rw detect the potential difference across the resistors of each phase using amplifiers 21, 22, and 23, and the potential difference is input to the control device 10.

[0054] Further, the current sensor 6 can be provided on an electric wire connecting the series circuit of two switching elements of each phase and the coil of each phase. Alternatively, the current sensor can be provided on an electric wire connecting the inverter 4 and the direct-current power supply 3, and the current of each phase winding can be detected by a known "bus 1 shunt method".

[0055] 1-3. Electric power steering apparatus 100

[0056] The electric power steering apparatus 100 includes the control apparatus 10 of the rotary electric machine, the inverter 4, the rotary electric machine 1, and the drive force transmission mechanism 101 that transmits the drive force of the rotary electric machine 1 to the steering apparatus 102 of the vehicle.

[0057] The rotation axis of the rotor of the rotary electric machine 1 is linked with the steering apparatus 102 of the wheel 103 through the drive force transmission mechanism 101. For example, the electric power steering apparatus 100 includes a steering wheel 104 that the driver rotates to the right and left, a shaft 105 that is linked with the steering wheel 104 and transmits the steering torque of the steering wheel 104 to the steering apparatus 102 of the wheel 103, a torque sensor 106 that is installed on the shaft 105 and detects the steering torque Ts of the steering wheel 104, and the drive force transmission mechanism 101 such as a worm gear mechanism that links the rotation axis of the rotary electric machine 1 with the shaft 105. The output signal of the torque sensor 106 is input to the control apparatus 10 (input circuit 92).

[0058] 1-4. Control apparatus 10

[0059] The control apparatus 10 controls the rotary electric machine 1 via the inverter 4. As shown in FIG. 1, the control apparatus 10 includes a rotation detection section 31, a control angle calculation section 32, a current detection section 33, a voltage command value calculation section 34, and a switching control section 35, and the like. Each function of the control apparatus 10 is realized by a processing circuit included in the control apparatus 10. Specifically, as shown in FIG. 1, the control apparatus 10 includes, as the processing circuit, an arithmetic processing apparatus 90 (computer) such as a CPU (Central Processing Unit), a storage apparatus 91 that exchanges data with the arithmetic processing apparatus 90, an input circuit 92 that inputs an external signal to the arithmetic processing apparatus 90, and an output circuit 93 that outputs a signal from the arithmetic processing apparatus 90 to the outside, and the like. Figure 2 Figure 3

[0060] ​​As the arithmetic processing device 90, an ASIC (Application Specific Integrated Circuit), an IC (Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), various logic circuits, various signal processing circuits, and the like can be provided. Further, as the arithmetic processing device 90, a plurality of arithmetic processing devices of the same kind or different kinds can be provided to share the execution of each processing. As the storage device 91, a RAM (Random Access Memory) configured to be able to read and write data from and to the arithmetic processing device 90, a ROM (Read Only Memory) configured to be able to read data from the arithmetic processing device 90, and the like can be provided. The input circuit 92 is connected to various sensors such as the rotation sensor 2, the current sensor 6, the torque sensor 106, switches, and the like, and is provided with an A / D converter and the like that input output signals of these sensors and switches to the arithmetic processing device 90. The output circuit 93 is connected to electric loads such as a gate drive circuit that performs on-off driving of a switching element, and is provided with a drive circuit and the like that outputs control signals from the arithmetic processing device 90 to these electric loads.

[0061] Further, each function of each control section 31 to 35 and the like provided in the control device 10 is realized by the arithmetic processing device 90 executing software (program) stored in the storage device 91 such as a ROM in cooperation with other hardware of the control device 10 such as the storage device 91, the input circuit 92, and the output circuit 93. In addition, setting data such as an internal division ratio and a control gain used by each control section 31 to 35 and the like is stored in the storage device 91 such as a ROM as a part of the software (program). Hereinafter, each function of the control device 10 will be described in detail.

[0062] 1-4-1. Basic Control

[0063] The rotation detection section 31 detects the rotation angle θd of the rotor on the basis of the output signal of the rotation sensor 2. As the detected value θd of the rotation angle of the rotor, the rotation angle (pole position) of the magnetic pole (N pole) of the magnet at the electrical angle with respect to the winding position of the U phase is detected.

[0064] The current detection section 33 detects the currents Iud, Ivd, Iwd flowing through the three-phase windings on the basis of the output signals of the current sensor 6. The current detection section 33 detects the current Iud flowing through the U-phase winding, detects the current Ivd flowing through the V-phase winding, and detects the current Iwd flowing through the W-phase winding on the basis of the output signals of the current sensor 6. In addition, the current sensor 6 is configured to detect the winding currents of two phases, and the winding current of the remaining one phase can also be calculated on the basis of the detected values of the winding currents of the two phases. For example, the current sensor 6 detects the winding currents Ivd and Iwd of the V-phase and W-phase, and the winding current Iud of the U-phase can be calculated by Iud = -Ivd - Iwd.

[0065] The voltage command value calculation section 34 calculates the voltage command values Vuo, Vvo, Vwo to be applied to the three-phase windings on the basis of the control rotation angle θc calculated by the control angle calculation section 32 described later and the current detection values.

[0066] In the present embodiment, the voltage command value calculation section 34 includes a current command value calculation section 341, a current coordinate conversion section 342, a dq-axis voltage command value calculation section 343, and a voltage coordinate conversion section 344.

[0067] The current coordinate conversion section 342 converts the current detection values Iud, Ivd, Iwd of the three-phase windings into the current detection values Idd, Iqd of the d-axis and q-axis on the basis of the control rotation angle θc. In the present embodiment, the current coordinate conversion section 342 performs three-phase two-phase conversion and rotation coordinate conversion on the current detection values Iud, Ivd, Iwd of the three-phase windings on the basis of the control rotation angle θc, and thereby converts them into the current detection values Idd, Iqd of the d-axis and q-axis, as shown in the following equation.

[0068] [Math. 1]

[0069]

[0070] In addition, the d-axis is determined as the direction of the magnetic pole (N-pole) of the magnet, and the q-axis is determined as the direction that advances by 90 degrees in the electrical angle from the d-axis. In the present example, since the coordinate transformation is performed on the basis of the control rotation angle θc, the direction of the control rotation angle θc is the d-axis.

[0071] The current command value calculating section 341 calculates the current command values Ido, Iqo of the d-axis and the q-axis. The current command value calculating section 341 detects the steering torque Ts of the driver on the basis of the output signal of the torque sensor 106. Further, the current command value calculating section 341 sets the current command value Iqo of the q-axis on the basis of the steering torque Ts as shown in the following expression, and sets the current command value Ido of the d-axis to 0. That is, Id=0 control is performed. In the Id=0 control, the current command value Ido of the d-axis is set to 0. The Id=0 control is suitable for the surface magnet type rotary electric machine.

[0072] Iqo = Ka x Ts

[0073] Ido = 0 · · · (2)

[0074] Here, Ka is a constant, but can also vary depending on the steering torque Ts and the running speed of the vehicle, etc. Further, the current command value Iqo of the q-axis can be set on the basis of a known compensation control corresponding to the steering condition. In the case of the buried magnet type rotary electric machine, the current command values Ido, Iqo of the d-axis and the q-axis can also be set by maximum torque current control instead of the Id=0 control. In the maximum torque current control, the current command values Ido, Iqo of the d-axis and the q-axis that generate the maximum torque for the same current are calculated.

[0075] In a region where the rotational angular velocity is high, field weakening control that increases the current command value Ido of the d-axis in the negative direction compared to the current command value of the d-axis calculated by the Id=0 control or the maximum torque current control is performed. For example, the execution region of the field weakening control is set to a region where the rotational angular velocity ω is a base speed or more at which the amplitude of the line-to-line voltage output by the inverter reaches the direct current voltage Vdc.

[0076] Figure 4 The execution regions of each control when the Id=0 control and the field weakening control are performed in the surface magnet type rotary electric machine are shown. Figure 5 The execution regions of each control when the maximum torque current control and the field weakening control are performed in the buried magnet type rotary electric machine are shown.

[0077] The dq-axis voltage command value calculating section 343 performs current feedback control that changes the voltage command value Vdo of the d-axis and the voltage command value Vqo of the q-axis by PI control or the like so that the current detection value Idd of the d-axis approaches the current command value Ido of the d-axis and the current detection value Iqd of the q-axis approaches the current command value Iqo of the q-axis as shown in the following expression.

[0078] [Mathematical Expression 2]

[0079]

[0080]

[0081] Here, Kd, Kq are proportional gains, Td, Tq are integral time constants, and s is a Laplace operator.

[0082] In addition, feedforward control can be performed so that the d-axis current and the q-axis current are not disturbed. That is, "-ωc x Lq x Iqc" can be added to the voltage command value Vdo of the d-axis, and "ωc x (Ld x Idd + ψ)" can be added to the voltage command value Vqo of the q-axis. Here, ωc is a rotational angular velocity for control, which will be described later, and a detected value ωd of the rotational angular velocity, which will be described later, can be used instead of ωc. Lq is the inductance of the q-axis, Ld is the inductance of the d-axis, and ψ is the magnetomotive force of the magnet and the linkage flux of the winding.

[0083] The voltage coordinate conversion section 344 converts the voltage command values Vdo and Vqo of the d-axis and the q-axis into three-phase voltage command values Vuo, Vvo, and Vwo based on the rotational angle θc for control. In the present embodiment, the voltage coordinate conversion section 344 performs fixed coordinate conversion and two-phase / three-phase conversion on the voltage command values Vdo and Vqo of the d-axis and the q-axis based on the rotational angle θc for control, and converts them into the three-phase voltage command values Vuo, Vvo, and Vwo as shown in the following equation.

[0084] [Equation 3]

[0085]

[0086] In addition, the voltage coordinate conversion section 344 can apply known modulation such as two-phase modulation, third harmonic superposition, and the like to the three-phase voltage command values Vuo, Vvo, and Vwo.

[0087] The switching control section 35 turns on and off a plurality of switching elements included in the inverter 4 based on the three-phase voltage command values Vuo, Vvo, and Vwo. The switching control section 35 uses known carrier comparison PWM or space vector PWM.

[0088] When the carrier comparison PWM is used, the switching control section 35 compares the carrier with each of the voltage command values Vuo, Vvo, Vwo of the three phases, and turns on and off the plurality of switching elements based on the comparison result. The carrier is set to a triangular wave that vibrates with an amplitude of half the value of the direct current voltage Vdc / 2 centered on 0 in the PWM period Tc. For each phase, the switching control section 35 turns on the switching signal GP of the positive side switching element in a case where the carrier is lower than the voltage command value, turns on the positive side switching element, and turns off the switching signal GP of the positive side switching element in a case where the carrier CA exceeds the voltage command value, turns off the positive side switching element. On the other hand, for each phase, the switching control section 35 turns off the switching signal GN of the negative side switching element in a case where the carrier is lower than the voltage command value, turns off the negative side switching element, and turns on the switching signal GN of the negative side switching element in a case where the carrier CA exceeds the voltage command value, turns on the negative side switching element. In addition, for each phase, a short-circuit prevention period (dead time) in which both the positive side and negative side switching elements are turned off can be provided between the on period of the positive side switching element and the on period of the negative side switching element.

[0089] In the case of using the space vector PWM, the switching control section 35 generates a voltage command vector from the voltage command values Vuo, Vvo, Vwo of the three phases, decides the output time distribution of the seven basic voltage vectors in the PWM period based on the voltage command vector, and generates the switching signals that turn on and off each switching element in the PWM period based on the output time distribution of the seven basic voltage vectors.

[0090] 1-4-2. Control angle calculation section 32

[0091] The control angle calculation section 32 calculates the rotation angle θc for control. The control angle calculation section 32 estimates an estimated actual angle deviation Δθe that is a deviation of the rotation angle θc for control with respect to the true rotation angle of the rotor, based on information of the current detection value and information of the voltage command value. The control angle calculation section 32 calculates a detected angle deviation Δθd that is a deviation of the rotation angle θc for control with respect to the detected value θd of the rotation angle. Then, the control angle calculation section 32 calculates a control angle deviation Δθc by dividing the estimated actual angle deviation Δθe and the detected angle deviation Δθd. Then, the control angle calculation section 32 calculates the rotation angle θc for control by performing feedback control so that the control angle deviation Δθc approaches 0.

[0092] The control angle calculating section 32 makes the proportion Ke of the estimated actual angle deviation Δθe in the control angle deviation Δθc higher than the proportion Kd of the detected angle deviation in the case where the speed proportional physical quantity, which is proportional to the rotational angular velocity of the rotor, is higher than the speed threshold value Th, and makes the proportion Ke of the estimated actual angle deviation Δθe in the control angle deviation Δθc lower than the proportion Kd of the detected angle deviation in the case where the speed proportional physical quantity is lower than the speed threshold value Th.

[0093] According to this structure, the control rotational angle θc is calculated by performing feedback control so that the control angle deviation Δθc, which is obtained by dividing the estimated actual angle deviation Δθe and the detected angle deviation Δθd, is close to 0, and therefore, it is not configured to correct the sensor detection value of the rotational angular velocity with the feedback control value as in Patent Document 1, and it is not necessary to increase the response frequency of the feedback control to reduce the error of the alternating current component included in the sensor detection value of the rotational angle at high rotational speed. Therefore, it is possible to set the response frequency of the feedback control to a frequency that can respond to the vibration frequency of the mechanical rotational angle, which is relatively low, and to a frequency that does not respond to the noise component of the current detection value, which is relatively high. Further, at high rotational speed, since the proportion Ke of the estimated actual angle deviation Δθe is higher than the proportion Kd of the detected angle deviation Δθd, and the control rotational angle θc is calculated by feedback control so that the control angle deviation Δθc is close to 0, it is possible to suppress the case where the error of the alternating current component included in the detected value θd of the rotational angle is reflected in the control rotational angle θc, and it is possible to make the control rotational angle θc close to the true rotational angle. Therefore, at high rotational speed, it is possible to reduce the error of the alternating current component included in the detected value θd of the rotational angle, while suppressing the increase in the error of the rotational angle caused by the high-frequency noise component included in the current detection value. Further, at low rotational speed, even in the case where the proportion Kd of the detected angle deviation Δθd is higher than the proportion Ke of the estimated actual angle deviation Δθe, since the control rotational angle θc is calculated by feedback control so that the control angle deviation Δθc is close to 0, it is possible to suppress the case where the error of the alternating current component included in the detected value θd of the rotational angle is reflected in the control rotational angle θc.

[0094] <Detected angle deviation Δθd calculation>

[0095] Figure 6 A block diagram of the control angle calculating section 32 according to the present embodiment is shown. The control angle calculating section 32 calculates the detected angle deviation Δθd by subtracting the control rotational angle θc from the detected value θd of the rotational angle as shown in the following expression.

[0096] Δθd = θd - θc (5)

[0097] Calculation of estimated angle deviation Δθe

[0098] As described above, the control angle calculation section 32 estimates the estimated angle deviation Δθe, which is the deviation of the control rotation angle θc from the true rotation angle of the rotor, based on the information of the current detection values and the information of the voltage command values. In the present embodiment, the control angle calculation section 32 estimates the estimated angle deviation Δθe, which is the deviation of the control rotation angle θc from the true rotation angle of the rotor, based on the current detection values Idd, Iqd of the d-axis and the q-axis, the voltage command values Vdo, Vqo of the d-axis and the q-axis, and the control rotation speed ωc.

[0099] The control angle calculation section 32 calculates the estimated angle deviation Δθe using the following equation.

[0100] ΔVd = -Vdo + R x Idd - ωc x Lq x Iqd

[0101] ΔVq = Vqo - R x Iqd - ωc x Ld x Idd

[0102] Δθe = arctan(ΔVd / ΔVq)...(6)

[0103] where R is the resistance value of the winding set in advance, Lq is the inductance of the q-axis set in advance, and Ld is the inductance of the d-axis set in advance. Ld and Lq can also be set using the mapping data of the d-axis current and the q-axis current, taking into account the magnetic saturation of the permanent magnet. Equation (6) is a formula derived based on the voltage equation, ΔVd is the error of the d-axis voltage caused by the deviation of the control rotation angle θc from the true rotation angle (here, the rotation angle at which the voltage equation holds), and ΔVq is the error of the q-axis voltage caused by the deviation of the control rotation angle θc from the true rotation angle. Then, the estimated angle deviation Δθe, which is the deviation of the control rotation angle θc from the true rotation angle, is calculated by calculating the value of the inverse tangent function of ΔVd / ΔVq.

[0104] In addition, the detection value ωd of the rotation speed calculated by differentiating the detection value θd of the rotation angle can be used instead of the control rotation speed ωc. In addition, the voltage command values Vdo, Vqo of the d-axis and the q-axis can be replaced by the voltage detection values Vdd, Vqd of the d-axis and the q-axis obtained by detecting the U-phase applied voltage Vu_PWM, the V-phase applied voltage Vv_PWM, and the W-phase applied voltage Vw_PWM applied to the three-phase winding, and performing three-phase two-phase conversion and rotation coordinate conversion on the voltage detection values Vu_PWM, Vv_PWM, Vw_PWM of the three phases based on the control rotation angle θc.

[0105] In a case where the absolute value of the detected value of the rotational angular velocity ωd is smaller than a threshold value, the control angle calculation section 32 can stop using the estimated actual angle deviation Δθe of Expression (6), and set Δθe = 0. This is to prevent the error ΔVq of the q-axis voltage from approaching 0, ΔVd / ΔVq from becoming too large, and the calculation error of Δθe from becoming too large in a case where the rotational angular velocity is low.

[0106] <Calculation of the detected value of the rotational angular velocity ωd>

[0107] The control angle calculation section 32 calculates the detected value of the rotational angular velocity ωd using the following expression.

[0108] ωd(n) = {θd(n) - θd(n - 1)} / ΔT...(7)

[0109] Here, θd(n - 1) is the rotational angle detected at the previous operation timing, and θd(n) is the rotational angle detected at the present operation timing. ΔT is the operation period. A value obtained by low-pass filtering the calculated value of Expression (7) can be used as the detected value of the rotational angular velocity ωd.

[0110] <Calculation of the control angle deviation Δθc based on the estimated actual angle deviation Δθe>

[0111] The control angle calculation section 32 calculates a value obtained by adding a value obtained by multiplying the estimated actual angle deviation Δθe by an internal division ratio Ke of the estimated actual angle deviation and a value obtained by multiplying the detected angle deviation Δθd by an internal division ratio Kd of the detected angle deviation, as the control angle deviation Δθc, as shown in the following expression.

[0112] Δθc = Ke x Δθe + Kd x Δθd

[0113] Ke + Kd = 1, 0 ≤ Ke ≤ 1, 0 ≤ Kd ≤ 1...(8)

[0114] Here, the internal division ratio Ke of the estimated actual angle deviation is the proportion Ke of the estimated actual angle deviation Δθe in the control angle deviation Δθc, and the internal division ratio Kd of the detected angle deviation is the proportion Kd of the detected angle deviation Δθd in the control angle deviation Δθc. The internal division ratio Ke of the estimated actual angle deviation and the internal division ratio Kd of the detected angle deviation are respectively set in a range of 0 or more and 1 or less so that the sum of the internal division ratio Ke of the estimated actual angle deviation and the internal division ratio Kd of the detected angle deviation is 1.

[0115] Kd = 1 - Ke. Therefore, (Δθc - Δθe) : (Δθd - Δθc) = Ke : (1 - Ke) is obtained, and the control angle deviation Δθc is a value obtained by internally dividing the estimated actual angle deviation Δθe and the detected angle deviation Δθd in a ratio of Ke : (1 - Ke).

[0116] <Change in internal ratio corresponding to speed proportional physical quantity>

[0117] Figure 7 A setting example of the internal ratios Ke, Kd involved in the present embodiment is shown. In the present embodiment, the detected value ωd of the rotational angular velocity is used as the speed proportional physical quantity. In a case where the detected value ωd of the rotational angular velocity is higher than a speed threshold value Th set in advance, the control angle calculation section 32 makes the internal ratio Ke that estimates the actual angle deviation higher than the internal ratio Kd that detects the angle deviation, and in a case where the detected value ωd of the rotational angular velocity is lower than the speed threshold value Th, the control angle calculation section 32 makes the internal ratio Ke that estimates the actual angle deviation lower than the internal ratio Kd that detects the angle deviation. That is, in a case where the detected value ωd of the rotational angular velocity is higher than the speed threshold value Th, the control angle calculation section 32 makes the internal ratio Ke that estimates the actual angle deviation higher than 0.5, and makes the internal ratio Kd that detects the angle deviation lower than 0.5. Also, in a case where the detected value ωd of the rotational angular velocity is lower than the speed threshold value Th, the control angle calculation section 32 makes the internal ratio Ke that estimates the actual angle deviation lower than 0.5, and makes the internal ratio Kd that detects the angle deviation higher than 0.5. Also, the control rotational angular velocity ωc can be used instead of the detected value ωd of the rotational angular velocity.

[0118] As the detected value ωd of the rotational angular velocity increases within a range of the speed proportional physical quantity (in this example, referred to as a rotational angular velocity range, hereinafter referred to as a replacement angular velocity range) that includes the speed threshold value Th set in advance, the control angle calculation section 32 continuously increases the internal ratio Ke that estimates the actual angle deviation, and continuously decreases the internal ratio Kd that detects the angle deviation.

[0119] A value obtained by subtracting a prescribed value from the speed threshold value Th becomes a lower limit angular velocity ThL of the replacement angular velocity range, and a value obtained by adding the prescribed value to the speed threshold value Th becomes an upper limit angular velocity ThH of the replacement angular velocity range, and the replacement angular velocity range becomes a range from the lower limit angular velocity ThL to the upper limit angular velocity ThH. In the present embodiment, the speed threshold value Th is set to be equal to the rotational angular velocity ωd at which the engine torque T is maximum. Figure 7 In the example shown, the replacement angular velocity range is set so that the speed threshold value Th becomes the center of the replacement angular velocity range.

[0120] According to this structure, by continuously changing the internal ratios Ke, Kd within the replacement speed range, in a case where there is a difference between the estimated actual angle deviation Δθe and the detected angle deviation Δθd, it is possible to suppress the control angle deviation Δθc from changing sharply, the control rotational angle θc from changing sharply, and the torque from changing sharply. Therefore, it is possible to suppress the deterioration of the driver's steering feeling. Also, it is possible to make the internal ratios Ke, Kd change gradually before and after the speed threshold value Th.

[0121] As the detected value ωd of the rotational angular velocity increases in the replacement angular velocity range including the speed threshold Th, the control angle calculation section 32 continuously increases the internal ratio Ke of the estimated actual angular deviation from 0 to 1, and continuously decreases the internal ratio Kd of the detected angular deviation from 1 to 0. In addition, the control angle calculation section 32 sets the internal ratio Ke of the estimated actual angular deviation to 0 while setting the internal ratio Kd of the detected angular deviation to 1 in the case where the detected value ωd of the rotational angular velocity is lower than the replacement angular velocity range, and sets the internal ratio Ke of the estimated actual angular deviation to 1 while setting the internal ratio Kd of the detected angular deviation to 0 in the case where the detected value ωd of the rotational angular velocity is higher than the replacement angular velocity range.

[0122] <Speed threshold Th is set in correspondence with the execution region of the field weakening control>

[0123] The speed threshold Th is set in correspondence with the rotational angular velocity ωbd of the boundary between the execution region of the Id = 0 control or the maximum torque current control and the execution region of the field weakening control. The effect of this setting is explained below.

[0124] When there is an angular error Δθerr, the torque error ΔTerr can be approximated as shown in the following equation.

[0125]

[0126] Even if there is an error, since the angle error Δθerr is close to 0, cos(Δθerr) « sin(Δθerr), and thus the 1st term on the right side of equation (9) can be ignored. Therefore, when the absolute value of the d-axis current Id becomes large, the torque error ΔTerr becomes large. As described above, in the flux-weakening control, the current command value Id0 of the d-axis is increased in the negative direction compared to the current command value of the d-axis calculated by the Id = 0 control or the maximum torque current control. Therefore, in the execution region of the flux-weakening control, the absolute value of the d-axis current Id becomes large, and when there is an angle error Δθerr, the torque error ΔTerr becomes large. As described above, by setting the speed threshold value Th, the rotation angle θc for calculation is made such that the internal fraction Ke of the estimated actual angle deviation becomes high in the execution region of the flux-weakening control, and the estimated actual angle deviation Δθe is reduced, and thus the deviation of the rotation angle θc for calculation from the true rotation angle (the estimated actual angle deviation Δθe) becomes small, and the angle error Δθerr becomes small. As described using equation (6), the true rotation angle is the rotation angle in which the voltage equation holds, and the torque error ΔTerr of equation (9) is also derived based on the voltage equation, and thus it is possible to reduce the torque error ΔTerr by calculating the rotation angle θc for calculation such that the estimated actual angle deviation Δθe is reduced. The calculation accuracy of the estimated actual angle deviation Δθe of equation (6) becomes high in a case where the induced voltage is high, and thus in a region where the induced voltage is high in which the flux-weakening control is executed, it is possible to improve the reduction accuracy of the angle error Δθerr by increasing the internal fraction Ke of the estimated actual angle deviation.

[0127] In the present embodiment, when the detected value ωd of the rotation speed is larger than the lower limit speed ThL of the replacement speed range, the estimated actual angle deviation Δθe is reflected in the calculation of the rotation angle θc for control. Therefore, it is possible to set the speed threshold value Th and the replacement speed range such that the rotation speed ωbd of the boundary between the execution region of the Id = 0 control or the maximum torque current control and the execution region of the flux-weakening control is the lower limit speed ThL or more of the replacement speed range. For example, it is possible to set the speed threshold value Th to coincide with the rotation speed ωbd of the boundary. Or, it is possible to set the speed threshold value Th and the replacement speed range such that the rotation speed ωbd of the boundary is included in the replacement speed range. As shown in FIG. 6, in the case of the buried magnet type rotary electric machine, since the rotation speed ωbd of the boundary varies depending on the torque, the speed threshold value Th and the replacement speed range can also vary depending on the torque. Figure 5

[0128] Or, in the buried magnet type rotary electric machine, even in the maximum torque current control, the d-axis current becomes a value smaller than 0, and thus the speed threshold value Th and the replacement speed range can also be set in the execution region of the maximum torque current control.​

[0129] A rotational angular velocity ωc for control can be used as the speed proportional physical quantity. A physical quantity other than the rotational angular velocity can also be used as the speed proportional physical quantity. For example, an induced voltage generated in a winding is proportional to the rotational angular velocity, and an applied voltage of the winding is proportional to the induced voltage. As the speed proportional physical quantity, a magnitude of a voltage vector of voltage command values Vdo, Vqo of d- and q-axes or a sum of squares of Vdo and Vqo can be used.

[0130] In addition, in a case where the DC voltage Vdc is lower than the voltage threshold value, the control angle calculation portion 32 can fix the inner fraction Ke that estimates the actual angle deviation to 0 and fix the inner fraction Kd that detects the angle deviation to 1, so that the estimated actual angle deviation Δθe is not reflected in the control angle deviation Δθc. This is because, as the DC voltage Vdc decreases, the base speed decreases, and the field weakening control is performed from a lower rotational speed, but at a low rotational speed, the induced voltage is low, so that the estimation accuracy of the estimated actual angle deviation Δθe of Equation (6) decreases.

[0131] <Calculating a rotational angle θc for control based on the control angle deviation Δθc>

[0132] As described above, the control angle calculation portion 32 calculates the rotational angle θc for control by performing feedback control so that the control angle deviation Δθc approaches 0. In the present embodiment, the control angle calculation portion 32 changes the rotational angular velocity ωc for control by performing feedback control so that the control angle deviation Δθc approaches 0, and integrates the rotational angular velocity ωc for control to calculate the rotational angle θc for control.

[0133] According to this structure, the rotational angular velocity ωc for control is changed by feedback control, so that it is not necessary to directly change the rotational angle θc for control by feedback control, and it is not necessary to increase the response frequency of the feedback control to the rotational frequency. Therefore, it is possible to make the response frequency of the feedback control lower than the rotational frequency, and it is possible to set the response frequency of the feedback control according to the vibration frequency of the mechanical rotational angular velocity.

[0134] For example, the control angle calculation portion 32 performs feedback control that changes the rotational angular velocity ωc for control so that the control angle deviation Δθc approaches 0 by PI control as shown in the following equation.

[0135] ωc = Kc x (1 + 1 / (Tc x s)) x Δθc... (10)

[0136] Here, Kc is a proportional gain, Tc is an integral time constant, and s is a Laplace operator. In addition, various feedback controls such as PID control can be used in addition to PI control.

[0137] <response frequency from Δθc to θc>

[0138] The transfer function G from the control angle deviation Δθc to the control rotation angle θc is the following formula.

[0139] G(s) = θc / Δθc = Kc x (1 + 1 / (Tc x s)) / s

[0140] ... (11)

[0141] According to Non-Patent Literature 1 (Kuriyama et al., "Torque Reduction Control Method for Electric Power Steering", Transactions of the Japan Society of Mechanical Engineers (C), Vol. 68, No. 675), it is known that the steering speed of steering vibrates at approximately 35 Hz (since in Figure 9 Figure 9 0.1 s is approximately 3.5 cycles). Therefore, the real speed variation of steering can occur at this degree of frequency. Therefore, the response from the control angle deviation Δθc to the control rotation angle θc needs to be 35 Hz or more, and it is preferably approximately 3 times, 90 to 100 Hz, and more preferably 5 times, 175 Hz or more. The vibration frequency of this rotation speed corresponds to the resonance frequency of the mechanical power transmission mechanism linked to the rotation axis of the rotor.

[0142] Here, if the transfer function G of formula (11) is expressed in a Bode chart, it is Figure 8 where Tc = 5 / Kc. According to this chart, the transfer function G is 0 dB at ω = Kc [rad / s], and the cut-off frequency is the characteristic of a 1st order low-pass filter of the proportional gain Kc [rad / s]. Here, the reason for being a 1st order low-pass filter is because, near 0 dB, it is -20 dB / dec.

[0143] Therefore, for the response from the control angle deviation Δθc to the control rotation angle θc, if the input angular frequency ω is below the proportional gain Kc, θc responds so that Δθc = 0, and if the input angular frequency ω exceeds Kc, θc can no longer follow the variation of Δθc.

[0144] ​Therefore, the response from the control angle error Δθc to the control rotation angle θc needs to be 35 Hz or more, which means that the proportional gain Kc needs to be 2π x 35 [rad / s] or more. Further, in order to set the response to about 3 times, 90 to 100 Hz, the proportional gain Kc needs to be set to 2π x 90 to 2π x 100 [rad / s], and in order to set the response to 5 times, 175 Hz or more, the proportional gain Kc needs to be set to 2π x 175 [rad / s] or more. In summary, the proportional gain Kc needs to be at least 2π x 35 [rad / s], and in consideration of a margin, 2π x 90 to 2π x 100 [rad / s] which is about 3 times, or more preferably 2π x 175 [rad / s] or more.

[0145] By setting the proportional gain Kc in this way, the response frequency (cut-off frequency) from the control angle error Δθc to the control rotation angle θc can be set to be higher than the frequency of the actual speed variation, 35 Hz, the control rotation angle θc can follow the actual speed variation, and the torque variation due to the angle error can be suppressed. On the other hand, the high-frequency vibration component of the control angle error Δθc due to the noise component included in the current detection value or the noise component included in the angle detection value can be cut off and not reflected in the control rotation angle θc. Therefore, by setting the response frequency (cut-off frequency) from the control angle error Δθc to the control rotation angle θc to be between 3 times and 5 times the frequency of the actual speed variation (for example, 90 Hz or more), the control rotation angle θc can follow the actual speed variation, and can not be easily affected by the noise component of the current detection value. As a result, the torque variation can be reduced, and the rotary electric machine can be quieted.

[0146] Further, the response frequency (cut-off frequency) from the control angle error Δθc to the control rotation angle θc is set to be lower than the rotation frequency corresponding to the speed threshold Th. According to this structure, in a region where the rotation speed is higher than the speed threshold Th and the internal fraction Ke of the estimated actual angle error Δθe is higher than the internal fraction Kd of the detected angle error Δθd, the case where the noise component of the rotation frequency included in the current detection value or the like is reflected in the control rotation angle θc can be suppressed.

[0147] In addition, the response frequency (cutoff frequency) from the control angle deviation Δθc to the control rotation angle θc is set to be higher than the mechanical resonance frequency (35 Hz in this example) generated in the rotation speed of the rotor. In particular, the response frequency (cutoff frequency) from the control angle deviation Δθc to the control rotation angle θc can be set to be between 3 times and 5 times the mechanical resonance frequency (35 Hz in this example) generated in the rotation speed of the rotor. According to this configuration, the control rotation angle θc can follow the variation in the mechanical rotation speed, and can not be easily affected by high-frequency noise components.

[0148] On the other hand, in the technology of Patent Literature 1, as described above, the feedback controller that calculates Δωlc requires a follow-up performance of the frequency up to the maximum rotation speed, requires an advanced microcomputer, and it is difficult to separate from the noise components of the current detection value included in Δθdc. On the other hand, in the present application, the response frequency can be set in accordance with the frequency of the actual speed variation that is lower than the maximum rotation frequency, without requiring the frequency follow-up performance of Patent Literature 1. Therefore, it is easy to separate from the noise components of the current detection value, and a low-level microcomputer (CPU) can be used.

[0149] 2. Embodiment 2

[0150] A rotating electrical machine 1, a power converter 4, and a control device 10 according to Embodiment 2 will be described. The same structure as that of Embodiment 1 described above will be omitted from the description. The basic structure of the rotating electrical machine 1, the power converter 4, and the control device 10 according to the present embodiment is the same as that of Embodiment 1, but the control rotation angle θc is limited by upper and lower limits, unlike Embodiment 1. Figure 9 is a block diagram of the control angle calculation section 32.

[0151] In the present embodiment, the control angle calculation section 32 calculates an upper limit value θcmax and a lower limit value θcmin of the control rotation angle based on the detected value θd of the rotation angle. Then, in a case where the control rotation angle θc deviates from the range from the upper limit value θcmax to the lower limit value θcmin, the control angle calculation section 32 corrects the control rotation angle θc based on the detected value θd of the rotation angle.

[0152] For example, the control angle calculation section 32 calculates the upper limit value θcmax and the lower limit value θcmin by adding a predetermined limit angle width Δθlmt to the detected value θd of the rotation angle and subtracting the predetermined limit angle width Δθlmt from the detected value θd of the rotation angle, as shown in the following expression. The limit angle width Δθlmt is set to be, for example, within 90 degrees in electrical angle.

[0153] θcmax = θd + Δθlmt

[0154] θcmin= θd- ΔθImt... (12)

[0155] The control angle calculation section 32 upper and lower limit restricts the control rotation angle θc by the upper limit value θcmax and the lower limit value θcmin as shown in the following equation.

[0156] 1) In the case of θc > θcmax

[0157] θc = θcmax

[0158] 2) In the case of θc < θcmin... (13)

[0159] θc = θcmin

[0160] 3) In the case of θcmin ≤ θc ≤ θcmax

[0161] θc = θc

[0162] Thus, by restricting the control rotation angle θc using the upper limit value θcmax and the lower limit value θcmin set based on the detected value θd of the rotation angle, even in the case where an abnormality occurs in the calculated value of the control rotation angle θc, the control rotation angle θc can be maintained within an appropriate range, and the performance of the rotary electric machine can be prevented from deteriorating greatly.

[0163] In addition, the present application can also be used in the case where the rotary sensor is multiplexed. For example, in the case where a rotary sensor of a double system (for example, a double system rotary transformer or a double system MR sensor) is used, the rotation angle detected by the rotary sensor of the normal one system can be used as the detected value θd of the rotation angle.

[0164] In addition, the rotary electric machine 1 can be provided as a driving force source for various devices other than the electric power steering device 100. For example, the rotary electric machine 1 can be provided as a driving force source for wheels.

[0165] In addition, the stator can also be provided with a multiphase (for example, two phases, four phases) winding other than a three-phase winding.

[0166] In addition, the stator can also be provided with a plurality of sets (for example, two sets) of three-phase windings, and each part of the inverter and the control device can be provided corresponding to each set of three-phase windings.

[0167] While various exemplary embodiments and examples are described in this application, various features, methods, and functions described in the various embodiments and examples can be combined in any combination, as would be understood by one of ordinary skill in the art. For example, features described in one embodiment or example can be combined with features described in another embodiment or example. Further, various features, methods, and functions described herein can be implemented in software instructions, hardware, firmware, or any combination thereof. For example, various features can be implemented in any of the following: Java, C++, C, assembly language, or machine code. Accordingly, features described in various embodiments and examples can be implemented in any combination of hardware, software, and / or firmware. Therefore, the above description should not be interpreted as a limitation on claimed subject matter but merely an illustration as defined by the appended claims. It is therefore apparent that there is a need for a system and method for implementing the present application in diverse variations.

[0168] REFERENCE NUMERALS

[0169] 1 Rotary electric machine

[0170] 2 Rotation sensor

[0171] 3 DC power supply

[0172] 4 Power converter

[0173] 6 Current sensor

[0174] 10 Control device of rotary electric machine

[0175] 31 Rotation detection section

[0176] 32 Control angle calculation section

[0177] 33 Current detection section

[0178] 34 Voltage command value calculation section

[0179] 35 Switch control section

[0180] 100 Electric power steering apparatus

[0181] 101 Drive force transmission mechanism

[0182] 102 Steering apparatus

[0183] Kd Proportion (internal fraction) of detected angle deviation

[0184] Ke Proportion (internal fraction) of estimated actual angle deviation

[0185] Th Speed threshold value

[0186] Δθc Control angle deviation

[0187] Δθd Detected angle deviation

[0188] Δθe Estimated actual angle deviation

[0189] θc Rotation angle for control

[0190] θcmax Upper limit value

[0191] θcmin lower limit value

[0192] θd detected value of the rotation angle

[0193] ωc rotation angular velocity for control

[0194] ωd detected value of the rotation angular velocity

Claims

1. A control device of a rotary electric machine, The control device of the rotary electric machine controls a rotary electric machine having a stator provided with a multi-phase winding and a rotor provided with a magnet via a power converter, characterized by comprising: a rotation detection section that detects a rotation angle of the rotor based on an output signal of a rotation sensor; a control angle calculation section that calculates a control rotation angle of the rotor; a current detection section that detects a current flowing through the multiphase winding based on an output signal of a current sensor; a voltage command value calculation section that calculates a voltage command value applied to the multiphase winding based on the control rotation angle and a current detection value; and a switch control section that turns on and off a plurality of switching elements possessed by the power converter based on the voltage command value, in the control angle calculation section, a speculation actual angle deviation that is a deviation of the control rotation angle with respect to a true rotation angle of the rotor is estimated based on information of the current detection value and information of the voltage command value, a detection angle deviation that is a deviation of the control rotation angle with respect to a detection value of the rotation angle is calculated, a value obtained by adding a value obtained by multiplying the speculation actual angle deviation by a proportion of the speculation actual angle deviation and a value obtained by multiplying the detection angle deviation by a proportion of the detection angle deviation is calculated as a control angle deviation, the control rotation angle is calculated by performing feedback control so that the control angle deviation approaches 0, in a case where a speed proportional physical quantity that is a physical quantity proportional to a rotation angular velocity of the rotor is higher than a speed threshold value set in advance, the proportion of the speculation actual angle deviation in the control angle deviation is set to be higher than the proportion of the detection angle deviation, in a case where the speed proportional physical quantity is lower than the speed threshold value, the proportion of the speculation actual angle deviation in the control angle deviation is set to be lower than the proportion of the detection angle deviation.

2. The control device of a rotary electric machine according to claim 1, wherein as the speed proportional physical quantity increases within a range of the speed proportional physical quantity including the speed threshold value set in advance, the control angle calculation section continuously increases the proportion of the speculation actual angle deviation and continuously decreases the proportion of the detection angle deviation.

3. The control device of a rotary electric machine according to claim 1, wherein as the speed proportional physical quantity increases within a range of the speed proportional physical quantity including the speed threshold value set in advance, the control angle calculation section continuously increases the proportion of the speculation actual angle deviation from 0 to 1 and continuously decreases the proportion of the detection angle deviation from 1 to 0, in a case where the speed proportional physical quantity is lower than the range of the speed proportional physical quantity, the proportion of the speculation actual angle deviation is set to 0 and the proportion of the detection angle deviation is set to 1, in a case where the speed proportional physical quantity is higher than the range of the speed proportional physical quantity, the proportion of the speculation actual angle deviation is set to 1 and the proportion of the detection angle deviation is set to 0. ​ 4. The control device of a rotary electric machine according to any one of claims 1 to 3, characterized in that the speed threshold value is set in correspondence with the speed ratio physical quantity of a boundary between an execution region of Id = 0 control or maximum torque current control and an execution region of field weakening control.

5. The control device of a rotary electric machine according to any one of claims 1 to 3, characterized in that the control angle calculation section changes a rotational angular velocity of the control of the rotor by performing feedback control so that the control angle deviation approaches 0, and integrates the rotational angular velocity of the control to calculate the rotational angle of the control.

6. The control device of a rotary electric machine according to claim 5, characterized in that the voltage command value calculation section takes a direction of the rotational angle of the control as a d-axis, takes a direction that advances by 90 degrees in electrical angle from the d-axis as a q-axis, converts current detection values of the multiphase winding into d-axis and q-axis current detection values based on the rotational angle of the control, and changes d-axis and q-axis voltage command values so that the d-axis and q-axis current detection values approach d-axis and q-axis current command values, respectively, and converts the d-axis and q-axis voltage command values into multiphase voltage command values based on the rotational angle of the control, the control angle calculation section estimates the estimated actual angle deviation, which is a deviation of the rotational angle of the control with respect to a true rotational angle of the rotor, based on the d-axis and q-axis current detection values, the d-axis and q-axis voltage command values, and the rotational angular velocity of the control.

7. The control device of a rotary electric machine according to any one of claims 1 to 3, characterized in that the control angle calculation section calculates an upper limit value and a lower limit value of the rotational angle of the control based on the detection value of the rotational angle, in a case where the rotational angle of the control deviates from a range of the upper limit value to the lower limit value, the rotational angle of the control is corrected based on the detection value of the rotational angle.

8. The control device of a rotary electric machine according to any one of claims 1 to 3, characterized in that a response frequency from the control angle deviation to the rotational angle of the control is set lower than a rotational frequency corresponding to the speed threshold value.

9. The control device of a rotary electric machine according to any one of claims 1 to 3, characterized in that a response frequency from the control angle deviation to the rotational angle of the control is set higher than a mechanical resonance frequency generated in a rotational angular velocity of the rotor.

10. The control device of a rotary electric machine according to any one of claims 1 to 3, characterized in that a response frequency from the control angle deviation to the rotational angle of the control is set between 3 times and 5 times a mechanical resonance frequency generated in a rotational angular velocity of the rotor.

11. An electric power assisted steering apparatus characterised in that, including: the control device of a rotary electric machine according to any one of claims 1 to 8; the power converter; the rotary electric machine; and a drive force transmission mechanism that transmits a drive force of the rotary electric machine to a steering device of a vehicle, The response frequency from the control angle deviation to the rotation angle for control is set to 90 Hz or more.

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