Motor control device and electric vehicle

Abstract

In order to quickly generate a d-axis current command value and a q-axis current command value that can satisfy a torque accuracy at a higher level, a motor control device (100) of the present application includes a d-axis current command value generation section (106) and a q-axis current command value generation section (112). The d-axis current command value generation section (106) generates a d-axis current command value (Idp) based on a torque command value (T). The q-axis current command value generation section (112) generates a q-axis current command value (Iq) based on the torque command value (T), a magnet torque of a motor, a reluctance torque of the motor, and the d-axis current command value (Id).

Description

Technical Field

[0001] This invention relates to electric motor control devices and electric vehicles. Background Technology

[0002] For example, in motor control, such as in automobiles where a permanent magnet synchronous motor is used as the main motor, a high level of torque accuracy is required. Patent Document 1 discloses a technique that improves torque accuracy by controlling the motor based on d-axis and q-axis current command values ​​generated taking into account the magnet temperature of the motor, thereby addressing flux limitation and torque command values.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-034471 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] However, in the aforementioned prior art, since d-axis and q-axis current command values ​​are generated based on the temperature of each magnet of the motor to address flux limitations and torque command values, a high-dimensional mapping is required, resulting in increased program size and reduced readability. Furthermore, to meet the torque accuracy requirements at a high level, multiple influencing factors (torque, angular velocity (speed), DC voltage, rotor temperature, etc.) need to be considered, increasing the measurement or calculation time (hereinafter referred to as adaptation) used to generate the mapping.

[0008] The present invention was made in view of the above circumstances, and its purpose is to rapidly generate d-axis current command values ​​and q-axis current command values ​​that meet torque accuracy at a higher level.

[0009] Technical solutions to solve technical problems

[0010] As a way to solve the above problems, a motor control device controls the drive of a motor, characterized in that it includes: a d-axis current command value generation unit that generates a d-axis current command value based on a torque command value; and a q-axis current command value generation unit that generates a q-axis current command value based on the torque command value, the magnet torque of the motor, the reluctance torque of the motor, and the d-axis current command value.

[0011] Invention Effects

[0012] According to the present invention, d-axis current command values ​​and q-axis current command values ​​that meet torque accuracy at a higher level can be generated rapidly. Attached Figure Description

[0013] Figure 1 This is a structural diagram of the electric vehicle system involved in Implementation Method 1.

[0014] Figure 2A This is a structural diagram (front section) showing the motor control device according to Embodiment 1.

[0015] Figure 2B This is a structural diagram (rear section) showing the motor control device according to Embodiment 1.

[0016] Figure 3 This is a diagram illustrating the calculation mapping of drag torque compensation values ​​according to Embodiment 1.

[0017] Figure 4 This is a diagram used to illustrate the drag torque compensation value involved in Embodiment 1.

[0018] Figure 5 This is a diagram illustrating the torque limit value calculation mapping involved in Embodiment 1.

[0019] Figure 6 This is a diagram illustrating the torque limiter according to Embodiment 1.

[0020] Figure 7 This is a diagram illustrating the Id calculation mapping involved in Implementation 1.

[0021] Figure 8 This is a diagram showing the structure of the d-axis current command value correction unit according to Embodiment 1.

[0022] Figure 9 This is a diagram illustrating the Gmf calculation mapping involved in Implementation 1.

[0023] Figure 10 This is a diagram illustrating the Gms mapping involved in Implementation 1.

[0024] Figure 11 This is a diagram showing the operating point of the motor control device according to Embodiment 1 on the dq-axis current plane.

[0025] Figure 12 This is a diagram used to illustrate the drag torque compensation value involved in Embodiment 2.

[0026] Figure 13 This is a diagram showing the structure of the d-axis current command value correction unit according to Embodiment 3.

[0027] Figure 14 This is a diagram showing the structure of the second d-axis current command generation unit according to Embodiment 3.

[0028] Figure 15This is a diagram showing the structure of the magnetic weakening control unit according to Embodiment 3.

[0029] Figure 16 This is a structural diagram (rear section) showing the motor control device according to Embodiment 4.

[0030] Figure 17 This is a diagram showing the structure of the d-axis current command value correction unit according to Embodiment 4.

[0031] Figure 18 This is a diagram showing the structure of the d-axis current command value correction unit according to Embodiment 5.

[0032] Figure 19 This is a structural diagram (rear section) showing the motor control device according to Embodiment 6.

[0033] Figure 20 This is a diagram showing the structure of the d-axis current command value correction unit according to Embodiment 6. Detailed Implementation

[0034] The embodiments described below with reference to the accompanying drawings are described. Furthermore, the following embodiments are not intended to limit the invention of this application, and not all constituent elements and combinations thereof described in the embodiments are necessary for the solution of the invention. Unless otherwise specified, the number of each constituent element in the following embodiments may be singular or plural.

[0035] In the following embodiments, items that overlap with previously described embodiments are given the same reference numerals, and descriptions of subsequent embodiments are omitted; the focus is on the differences. Furthermore, in the following embodiments, combinations of part or all of one embodiment with part or all of another embodiment are also included in the embodiments covered by this application, provided they are not contradictory and are consistent.

[0036] In the following description, identical or similar constituent elements are assigned the same labels. Additionally, when there are multiple identical or similar constituent elements, different subscripts may be added to the same labels for description. Furthermore, when it is not necessary to distinguish between multiple constituent elements, subscripts may be omitted for description.

[0037] [Implementation Method 1]

[0038] (Structure of the electric vehicle system 1 according to Embodiment 1)

[0039] Figure 1This is a structural diagram of the electric vehicle system 1 according to Embodiment 1. In the electric vehicle system 1, a pair of axles 1a and 1b are supported on the vehicle body. Wheels 2a and 2b are fixed to both ends of one axle 1a, and wheels 2c and 2d are fixed to both ends of the other axle 1b. An electric motor 5 is connected to one axle 1a, and the rotational power of the electric motor 5 is transmitted to the wheels 2a and 2b via the axle 1a. The electric motor control device 100 is based on the torque command value T0 input from a host system (not shown). The electric motor 5 is used to drive the electric motor 5. In this embodiment, the electric motor 5 is an IPMSM (Interior Permanent Magnet Synchronous Motor), but it is not limited to this. The electric vehicle system 1 is an example of an electric vehicle such as a car, electric bicycle, or railway vehicle that uses the electric motor 5 as a drive source.

[0040] (Structure of the electric motor control device 100 according to Embodiment 1)

[0041] Figure 2A and Figure 2B This is a structural diagram of the motor control device 100 according to Embodiment 1. The motor control device 100 drives the motor 5 by controlling the torque generated by the motor 5 through vector control based on the d-axis current detection value Idc and the q-axis current detection value Iqc.

[0042] Figure 2A This shows the torque command value T0 input from the host system. To generate the d-axis current command value Id and q-axis current command value Iq Block diagram of the motor control device 100. Figure 2B This shows the d-axis current command value Id. and q-axis current command value Iq This is a block diagram of a motor control device 100 that drives and controls the motor 5. The motor control device 100 is composed of a microcomputer that executes programs to implement various processing functions.

[0043] like Figure 2A As shown, the motor control device 100 includes: a flux limit value generation unit 101, a drag torque compensation unit 102, an adder 103, a torque limit value generation unit 104, and a torque command value limiting unit 105. Furthermore, the motor control device 100 includes: a d-axis current command value generation unit 106, a field weakening control unit 107, a d-axis current command value correction unit 108, an adder 109, a magnet torque gain generation unit 110, a reluctance torque gain generation unit 111, and a q-axis current command value generation unit 112.

[0044] The flux limit value generation unit 101 inputs the DC voltage Vdc output by the voltage detector 30 ( Figure 2B ), and the angular velocity ω of the motor 5 generated by the frequency calculation unit 114 ( Figure 2B ), and calculates the flux limit value λlim according to, for example, Equation (1). In Equation (1), Kmod is the voltage utilization factor, and Kmar is the margin rate with respect to the voltage utilization.

[0045] λlim={(Vdc / 2) Kmod Kmar} / ω (1)

[0046] The drag torque compensation unit 102 inputs the flux limit value λlim and the DC voltage Vdc, and outputs the drag torque compensation value Tdrag . The drag torque compensation unit 102, for example, refers to the drag torque compensation value calculation map T1 ( Figure 3 ), and obtains the drag torque compensation value Tdrag corresponding to the combination of the flux limit value λlim and the DC voltage Vdc . The adder 103 adds the torque command value T0 and the drag torque compensation value Tdrag output by the drag torque compensation unit 102 to generate the torque command value T after compensating for the drag torque of the motor 5.

[0047] Here, referring to Figure 4 , the drag torque compensation value Tdrag corresponding to the flux limit value λlim for each DC voltage Vdc of the motor 5 used in Embodiment 1 is described. Figure 4 is a diagram for explaining the drag torque compensation value Tdrag involved in Embodiment 1.

[0048] Figure 4 For each of, for example, three representative values of the DC voltage Vdc = V1, V2, V3, the drag torque compensation value Tdrag corresponding to each flux limit value λlim is plotted as the drag torque compensation value Tdrag involved in Embodiment 1.

[0049] From Figure 4 , it can be seen that the drag torque compensation value Tdrag corresponding to each flux limit value λlim shows little difference among the representative values V1, V2, V3 of the DC voltage Vdc (where V1 < V2 < V3). Therefore, even with the drag torque compensation value Tdrag corresponding to the representative value, Linear interpolation is used to calculate the drag torque compensation value Tdrag corresponding to the detected value V of DC voltage Vdc. This also reduces errors. Therefore, even when the representative value of the DC voltage Vdc is small, the iron loss and mechanical loss of the rotor of motor 5 can be compensated with high precision through simple linear interpolation.

[0050] return Figure 2A The torque limit value generation unit 104 takes the flux limit value λlim as input, and calculates the mapping T2 (for example, by referring to the torque limit value) Figure 5 ), obtain and output the torque limit value Tlim corresponding to the flux limit value λlim.

[0051] Torque command value limiting unit 105 limits torque command value T and the torque limit value Tlim as input, for example through the torque limiter T3 ( Figure 6 The output will be the torque command value T. The torque command value T is limited to the upper limit (Tlim) and the lower limit (-Tlim). .

[0052] Alternatively, the torque command value limiting unit 105 can directly take the DC voltage Vdc and angular velocity ω as inputs and output the torque command value T. Furthermore, the torque limit value generation unit 104 can also directly take the DC voltage Vdc and angular velocity ω as inputs and output the torque limit value Tlim.

[0053] The d-axis current command value generation unit 106 generates the torque command value T. And the magnetic flux limit value λlim is used as input, for example, referring to Id to calculate the mapping T4 ( Figure 7 ), obtain and output the torque command value T The combination of the magnetic flux limit value λlim and the corresponding d-axis current command value Idp .

[0054] The field weakening control unit 107 includes a subtractor 107a and an integrator with amplitude limiting 107b. The subtractor 107a calculates the maximum output voltage Vam and voltage amplitude Va (described later). The voltage difference ΔVa is output to the integrator 107b with a limiting factor. The integrator 107b multiplies the voltage difference ΔVa by the cutoff frequency ωfw of the field weakening control, and then divides it by the d-axis inductance Ld and the angular velocity ω. The integral is then performed, and the result is output as the feedback d-axis current command value IdFB. .

[0055] The 107b integrator with limiting is used for limiting, so that the feedback d-axis current command value IdFB is... It is not a positive value. Specifically, the integrator 107b with a limiting value has a variation limiting value. When the voltage between the terminals of the motor 5 is greater than the specified maximum output voltage, the feedback d-axis current command value IdFB is maintained by setting the variation limiting value in the positive direction to zero. The variation limit value is the d-axis current command value Idp set when the voltage between the terminals of motor 5 is below the specified maximum output voltage. The change in magnitude is a value that is sufficiently slow relative to the response of the field weakening control unit 107.

[0056] Therefore, the field weakening control unit 107 generates and outputs the command value Idp for correcting the d-axis current. Feedback d-axis current command value IdFB This is to ensure that the voltage between the terminals of motor 5 does not exceed the specified maximum output voltage.

[0057] When the voltage between the terminals of motor 5 is above the specified value, i.e., the voltage amplitude Va When the value is above a specified value, the d-axis current command value correction unit 108 generates a value corresponding to the d-axis current command value Idp. The sum of the positive correction values ​​Idc The d-axis current command value correction unit 108 sets one or more reference modulation rates, and based on the voltage amplitude calculation unit 115 ( Figure 2B The generated voltage amplitude Va The magnitude relationship between the value and the reference modulation rate generates a positive correction amount Idc. .

[0058] The processing of the d-axis current command value correction unit 108 is explained in detail. Figure 8 This diagram illustrates the structure of the d-axis current command value correction unit 108 according to Embodiment 1. The d-axis current command value correction unit 108 includes a modulation rate calculation unit 1081, a reference modulation rate calculation unit 1082, and a correction command generation unit 1083. The field weakening control unit 107 outputs a feedback d-axis current command value IdFB as a negative correction amount. In contrast, the d-axis current command value correction unit 108 generates and outputs a positive correction amount Idc. .

[0059] Modulation rate calculation unit 1081 is based on voltage amplitude calculation unit 115 ( Figure 2B Voltage amplitude Va The modulation rate Ma is calculated according to equation (2) based on the DC voltage Vdc of the DC power supply 20 detected by voltage detector 30 and the DC voltage Vdc of the DC power supply 20. .

[0060] Ma *= Va / (Vdc / 2) (2)

[0061] In addition, when the voltage amplitude Va is calculated based on the voltage detection value in the voltage amplitude calculation unit 115, the modulation rate calculation unit 1081 can also derive the modulation rate Ma based on the voltage detection value by replacing Va in Equation (2) with Va. That is, the modulation rate calculation unit 1081 calculates the modulation rate Ma (Ma ) of the motor control device 100 based on the DC voltage Vdc of the DC power supply 20 supplied to the motor control device 100 and the voltage amplitude Va (Va ) calculated by the voltage amplitude calculation unit 115. )

[0062] The reference modulation rate calculation unit 1082 calculates and sets the first reference modulation rate Ma1 and the second reference modulation rate Ma2. Here, for example, the values of Ma1 and Ma2 are determined to satisfy the relationship Ma1 < Ma2 ≤ 1.

[0063] The correction instruction generation unit 1083 generates a positive correction amount Idc based on the magnitude relationship between the modulation rate Ma[[ID=,18]] from the modulation rate calculation unit 1081 and the first reference modulation rate Ma1 and the second reference modulation rate Ma2 from the reference modulation rate calculation unit 1082. Here, according to the magnitude relationship between Ma and Ma1 and Ma2, any one of the following equations (3) to (5) is used to generate and output a positive correction amount Idc . .

[0064] (a) When 0 ≤ Ma < Ma1, Idc *= 0 (3).

[0065] (b) When Ma1 ≤ Ma < Ma2, Idc *= (Idc2 / (Ma2 - Ma1)) [[ID=4 ,3]]*(Ma * - Ma1) (4).

[0066] (c) When Ma2 ≤ Ma , Idc *= Idc2 [[ID=,54]](5).

[0067] In addition, in the correction instruction generation unit 1083, based on the d-axis current command value Idp The optimal current Idopt is preset in equations (4) and (5) to the value of Idc2. The optimal current Idopt is based on the voltage amplitude Va. The moment after the maximum output voltage Vam is exceeded, Va = The current value at which the Vam relationship holds true.

[0068] Specifically, the correction instruction generation unit 1083 sets the value of Idc2 so that the absolute value of the current value based on equation (4) |Idp + Idc | Less than the absolute value of the optimal current Idopt, and insufficient as a field-weakening current. The value of Idc2 can be determined based on the d-axis current command value Idp. The value of the DC voltage Vdc may be changed. Therefore, the field weakening control unit 107 adjusts the modulation rate Ma. Perform actions to compensate for insufficient magnetic weakening current and generate feedback d-axis current command value IdFB. Therefore, it can avoid the situation of excessive current flowing through.

[0069] However, if the positive correction amount Idc is applied outside of the time of field weakening control... The d-axis current command value Idp is added before calibration. If the operating point of the motor deviates from the optimal condition, it will lead to a decrease in operating efficiency. Therefore, as shown in equation (3), the correction command generation unit 1083 adjusts the modulation rate Ma. When the modulation rate is less than the first reference modulation rate Ma1, the positive correction amount Idc will be applied. Set to zero. Therefore, the d-axis current command value correction unit 108 can immediately generate a positive correction amount Idc before transitioning to field weakening control. .

[0070] As for the operation timing of the d-axis current command value correction unit 108, for example, the voltage amplitude Va can be considered. A positive correction value Idc is generated at the point when the maximum output voltage Vam is reached. The method. However, in this method, the accompanying d-axis current command value Id Rapid changes in torque can generate torque surges.

[0071] Therefore, in the motor control device 100 according to this embodiment, control is performed so that the voltage amplitude Va A positive correction value Idc begins to gradually generate slightly before the maximum output voltage Vam is reached. Specifically, when applying sinusoidal modulation, the first reference modulation rate Ma1 is set to a value less than 1, and the second reference modulation rate Ma2 is set to 1. That is, by setting Ma1 < Ma2 = 1, torque surges can be reduced.

[0072] return Figure 2A The explanation is as follows. Adder 109 will add the above negative correction amount (feedback d-axis current command value IdFB). ) and positive correction amount Idc The d-axis current command value Idp generated by the d-axis current command value generation unit 106 is added to the d-axis current command value. The corrected d-axis current command value Id is output. .

[0073] The magnet torque gain generation unit 110 generates the torque command value T The rotor temperature tr of motor 5 is taken as input, and the magnet torque gain Gmf is output. The magnet torque gain generation unit 110 calculates the mapping T5, for example, with reference to Gmf. Figure 9 ), obtain the torque command value T The magnet torque gain Gmf corresponding to the combination of rotor temperature tr and rotor temperature tr.

[0074] Alternatively, the magnet torque gain generation unit 110 can also be configured to generate the q-axis current command value Iq. The rotor temperature tr of motor 5 is used as input, and the magnet torque gain Gmf is output.

[0075] The reluctance torque gain generation unit 111 generates the torque command value T and d-axis current command value Id As input, it outputs the reluctance torque gain Gms. The reluctance torque gain generation unit 111, for example, calculates the mapping T6 with reference to Gms. Figure 10 ), obtain the torque command value T and d-axis current command value Id The corresponding magnetoresistive torque gain Gms is obtained from the combination of these parameters.

[0076] Alternatively, the reluctance torque gain generation unit 111 can also be configured to generate the d-axis current command value Id. and q-axis current command value Iq As input, it outputs the reluctance torque gain Gms.

[0077] The q-axis current command value generation unit 112 generates the torque command value T. d-axis current command value Id The magnet torque gain Gmf and the reluctance torque gain Gms are used as inputs, for example, to generate and output the q-axis current command value Iq according to equation (6). Among them, for each value of motor 5 in equation (6), p is the number of pole pairs, Gmf is the magnet torque gain, Φ is the magnet flux coefficient, Gms is the reluctance torque gain, Ld is the d-axis inductance, and Lq is the q-axis inductance.

[0078] Iq* = 2 / 3 [T** / {p(Gmf Φ++ms(Ld-Lq)Id*)}] (6) Equation (6) is for the q-axis current command value Iq The torque equation obtained by solving the IPMSM is as follows. In equation (6), Φ varies according to the rotor temperature (magnet temperature) and the q-axis current detection value Iqc, and ΔL = Ld - Lq varies according to the d-axis current detection value Id and the q-axis current detection value Iq (independent of the rotational speed (angular velocity ω) or DC voltage Vdc). Using this, in equation (6), the terms contributing to torque accuracy can be reduced to a combination of two-dimensional mappings, reducing the number of fitting points while ensuring torque accuracy. In addition, the mechanical losses and iron losses (dragging torque) not included in the torque equation involved in equation (6) are corrected based on the rotational speed and DC voltage Vdc.

[0079] Next, turn to Figure 2B The motor control device 100 includes: a three-phase / dq conversion unit 113, a frequency calculation unit 114, a voltage amplitude calculation unit 115, a maximum output voltage calculation unit 116, a current control unit 117, a dq / three-phase conversion unit 118, and a PWM control unit 119.

[0080] Voltage detector 30 detects the voltage of DC power supply 20 and outputs it as DC voltage Vdc.

[0081] The current detector 40 detects the three-phase current values ​​Iu, Iv, and Iw flowing from the power converter 10 to the motor 5 in phases U, V, and W. The current detector 40 is composed of a Hall current transformer (CT), but is not limited to it.

[0082] The magnetic pole position detector 50 is composed of a rotary transformer or similar components located near the motor 5, and detects the magnetic pole position of the motor 5 and outputs magnetic pole position information θ. In addition, the power converter 10 is connected to a smoothing capacitor to smooth the DC voltage Vdc, but this is not shown in the figure.

[0083] The three-phase / dq converter 113 utilizes the magnetic pole position information θ detected by the magnetic pole position detector 50. The coordinate transformation is performed on the three-phase current values ​​Iu, Iv, and Iw detected by the current detector 40, and the d-axis current detection value Idc and the q-axis current detection value Iqc are output.

[0084] The frequency calculation unit 114 calculates the magnetic pole position information θ detected by the magnetic pole position detector 50. For example, the angular velocity ω of motor 5 can be output through differential operations.

[0085] The voltage amplitude calculation unit 115 refers to the d-axis voltage command value Vd output from the current control unit 117. q-axis voltage command value Vq According to equation (7), the voltage amplitude Va is calculated. Voltage amplitude Va This is the value corresponding to the voltage between the terminals of motor 5. Voltage amplitude Va This is an example of the estimated voltage amplitude of motor 5.

[0086] Va* = √{(Vd*) ２ +(Vq*) ２} (7)

[0087] The maximum output voltage calculation unit 116 calculates the maximum output voltage Vam based on the DC voltage Vdc. Here, when a sinusoidal modulation method is applied (a modulation method in which the ratio of the output voltage amplitude to the DC voltage Vdc is at most 0.866 (≈√3 / 2) when converted to line-to-line voltage), the maximum output voltage Vam is calculated according to equation (8). The maximum output voltage Vam is a value corresponding to the maximum output voltage of the inter-terminal voltage of the motor 5. The maximum output voltage Vam is an example of the target voltage of the motor 5.

[0088] Vam = Vdc / 2 (8)

[0089] In addition, Equation (8) shows an example of a sinusoidal modulation method, but if an overmodulation method (a modulation method that can output a higher voltage than the sinusoidal method but with increased voltage harmonic components) is applied, the maximum output voltage Vam can be increased by about 10% relative to Equation (8).

[0090] The current control unit 117 is controlled by the input voltage amplitude Va Maximum output voltage Vam, d-axis current command value Id q-axis current command value Iq The input information includes the d-axis current detection value Idc, the q-axis current detection value Iqc, and the angular velocity ω. Then, based on this input information, the current control unit 117 outputs a d-axis current command value Idc. The d-axis current detection value Idc and the q-axis current command value Iq are compared with the d-axis current detection value Idc and the q-axis current command value Iq. The d-axis voltage command value Vd is consistent with the q-axis current detection value Iqc. and q-axis voltage command value Vq .

[0091] The dq / three-phase converter 118 utilizes the magnetic pole position information θ detected by the magnetic pole position detector 50. The d-axis voltage command value Vd output by the current control unit 117 and q-axis voltage command value Vq Perform coordinate transformation and output the three-phase voltage command value Vu. Vv Vw .

[0092] The PWM control unit 119 controls the three-phase voltage command value Vu. Vv Vw The duty cycle signal is calculated with the DC voltage Vdc, and the duty cycle signal is compared with the carrier wave to generate the gate signal G, which is then output to the power converter 10.

[0093] In the power converter 10, an inverter is constructed from semiconductor switching elements, which are controlled to be turned on / off by a gate signal G. This converts the DC power supplied from the DC power supply 20 into AC power, thereby driving the rotation of the motor 5.

[0094] (The operating point of the motor control device 100 in Embodiment 1 on the dq axis current plane)

[0095] Reference Figure 11 The operating point of the motor control device 100 according to Embodiment 1 on the dq axis current plane will be described. Figure 11 This is a diagram showing the operating point of the motor control device 100 according to Embodiment 1 on the dq-axis current plane.

[0096] When the speed of motor 5 is low and the isovoltage ellipse L1 is sufficiently large, the intersection of the MTPA curve and the isotorque line L2 (the tangent point between the current limiting circle L3 and the isotorque line L2) becomes the operating point P1. The operating point P1 is determined by the d-axis current command value Idp output from the shaft current command value generation unit 106. and q-axis current command value Iq specified.

[0097] As the speed of motor 5 increases, the terminal voltage ellipse decreases, deviating from the operating point P1 of the MTPA curve and shifting to the field weakening region. Therefore, the intersection of the isovoltage ellipse L1 and the isotor line L2 under constant voltage conditions is used as the operating point P2, thus causing the d-axis current command value Idp to... Increase in the negative direction and decrease the q-axis current command value Iq. The operating point P2 is determined by the d-axis current command value Idp. Field weakening control, and q-axis current command value Iq specified.

[0098] When the speed of motor 5 increases further, even if the d-axis current command value Idp is increased... This state occurs when the voltage increases in the negative direction. In this region, the intersection of the MTPV curve and the terminal voltage ellipse (the tangent point of the isovoltage ellipse L1 and the isotorque line L2) is taken as the operating point P5. The operating point P5 is determined by the d-axis current command value Idp. Field weakening control, q-axis current command value Iq And the torque limit value Tlim is specified.

[0099] Furthermore, based on the d-axis current command value Idp output from the d-axis current command value generation unit 106 The operating point P3 of motor 5 is located near the intersection of the isovoltage ellipse L1 and the isotor line L2. Assume that due to parameter errors, the operating point P3 will deviate from this intersection point. At this time, the current command value Idp is... The commanded operating point P is located outside the isovoltage ellipse L1 ( Figure 11 In the case where point P2 is further outward than the midpoint, the operating point P is negatively corrected and moved to the intersection point within the isovoltage ellipse L1. On the other hand, based on the d-axis current command value Idp... The commanded operating point P is located inside the isovoltage ellipse L1. Figure 11 In the case where point P4 is further inward than the midpoint, a positive correction amount Idc corresponding to the modulation rate is used. The operating point P is positively corrected and moved to the intersection point within the isoelectric ellipse L1.

[0100] [Implementation Method 2]

[0101] In implementation method 1, the drag torque compensation value Tdrag is... This is set to a value corresponding to the flux limit value λlim under each DC voltage Vdc of the motor 5. In contrast, in embodiment 2, the drag torque compensation value Tdrag is... The value is set to correspond to the angular velocity ω under each DC voltage Vdc of the motor 5. In this embodiment, the drag torque compensation unit 102 inputs the DC voltage Vdc and angular velocity ω of the motor 5, and outputs the drag torque compensation value Tdrag. .

[0102] (The drag torque compensation value Tdrag involved in Implementation Method 2) )

[0103] Figure 12 This is used to explain the drag torque compensation value Tdrag involved in Embodiment 2. The image. Figure 12 For example, for each of the three representative DC voltage values ​​Vdc = V1, V2, and V3, the drag torque compensation value Tdrag corresponding to each angular velocity ω of the rotor of motor 5 is plotted. The drag torque compensation value Tdrag involved in Implementation Method 2 The chart.

[0104] Depend on Figure 12 It can be seen that the drag torque compensation value Tdrag corresponding to each angular velocity ω Among the representative values ​​V1, V2, and V3 of the DC voltage Vdc (where V1 < V2 < V3), the smaller the angular velocity ω, the more consistent the values; conversely, the larger the angular velocity ω, the greater the difference. Therefore, if the drag torque compensation value Tdrag corresponding to the representative value is used... Linear interpolation is used to calculate the drag torque compensation value Tdrag corresponding to the detected value V of DC voltage Vdc. If the number of representative values ​​for the DC voltage Vdc increases, the error will increase. Therefore, it is necessary to increase the number of representative values ​​for the DC voltage Vdc to suppress the error of linear interpolation. As the number of representative values ​​for linear interpolation increases, the linear interpolation becomes more complex, but the iron loss and mechanical loss of the rotor of motor 5 can be compensated by linear interpolation of the DC voltage.

[0105] (A variation of Implementation Method 2)

[0106] In implementation method 2, the drag torque compensation value Tdrag Set to the value of each DC voltage Vdc. However, it is not limited to this; the drag torque compensation value Tdrag... Alternatively, it can be set for all DC voltages Vdc, rather than for each individual DC voltage Vdc. For example, the drag torque compensation value Tdrag. The value corresponding to the angular velocity ω is obtained by referring to a one-dimensional mapping. In this modified example, the drag torque compensation unit 102 inputs the angular velocity ω of the motor 5 and outputs the drag torque compensation value Tdrag. Therefore, mechanical losses can be compensated with a simple structure.

[0107] [Implementation Method 3]

[0108] In Embodiment 1, the d-axis current command value correction unit 108 corrects the DC voltage Vdc and voltage amplitude Va based on the motor 5. modulation rate Ma To generate a positive correction value Idc In contrast, in implementation 3, the positive correction amount Idc Based on torque command value T d-axis current command value Idp And the maximum output voltage Vam and voltage amplitude Va It is generated by the voltage difference ΔVa.

[0109] In this embodiment, the motor control device 100 includes a d-axis current command value correction unit 108C instead of a d-axis current command value correction unit 108.

[0110] (Structure of the d-axis current command value correction unit 108C according to Embodiment 3)

[0111] Figure 13 This is a diagram showing the structure of the d-axis current command value correction unit 108C according to Embodiment 3. The d-axis current command value correction unit 108C includes: an MTd-axis current command value generation unit 108C1, a subtractor 108C2, and a second d-axis current command value generation unit 108C3.

[0112] The MTd axis current command value generation unit 108C1 generates the value based on the torque command value T. Generate the MTd-axis current command value IdMT, which serves as the d-axis current command value on the MTPA (Maximum Torque Per Ampere) curve. The MTd shaft current command value generation unit 108C1 can be constructed using a lookup table or expressed using an approximate formula. Although the MTd shaft current command value generation unit 108C1 shows the generation of the torque command value T... This can be used as an example of an input, but the rotor temperature Tr can also be used as an input, forming a two-input lookup table or approximation.

[0113] The subtractor 108C2 receives the MTd axis current command value IdMT. Subtract the d-axis current command value Idp generated by the d-axis current command value generation unit 106 from the middle. And the d-axis current command value is differentiated by ΔId The output is sent to the second d-axis current command value generation unit 108C3.

[0114] The second d-axis current command value generation unit 108C3 generates the d-axis current command value Idp based on the d-axis current command value Idp. With MTd axis current command value IdMT d-axis current command value difference ΔId And the maximum output voltage Vam and voltage amplitude Va The voltage difference ΔVa generates a positive correction Idc. .

[0115] (Structure of the second d-axis current command value generation unit 108C3 according to Embodiment 3)

[0116] Figure 14 This diagram illustrates the structure of the second d-axis current command value generation unit 108C3 according to Embodiment 3. The second d-axis current command value generation unit 108C3 includes: an upper limit value calculation unit 841, a subtractor 842, a limiter 843, an adder 844, and a memory 845.

[0117] When the voltage difference ΔVa is greater than or equal to the specified value ΔVconst, the upper limit calculation unit 841 calculates the upper limit value ΔI of the d-axis current command value difference according to equation (9). When the voltage difference ΔVa is less than the specified value ΔVconst, it outputs 0. Wherein, ΔVconst > 0.

[0118] ΔI=-dId_max(ωfw / 5)Δt (9)

[0119] Here, dId_max is the maximum compensation value of the d-axis current command value, for example, the compensation amount required at the highest temperature. Δt is the control operation period. In equation (9), in order to make the control of the upper limit value ΔI of the d-axis current command value difference slower than the voltage feedback control of the field weakening control unit 107, the cutoff frequency ωfw is divided by the divisor 5, and the gain is set to 1 / 5. As long as the divisor is a number greater than 1, the control of the upper limit value ΔI can be made slower than the voltage feedback control, even with the positive correction amount Idc. Changes in voltage amplitude Va If the maximum output voltage Vam is exceeded, the voltage feedback control will also activate immediately.

[0120] Subtractor 842 calculates the difference ΔId between the d-axis current command value and the subtractor. With positive correction amount Idc The limiter 843 limits the difference between the previous values ​​by using the upper limit of the difference between the difference calculated by the subtractor 842 and the upper limit value ΔI of the difference between the d-axis current command values ​​calculated by the upper limit value calculation unit 841. The adder 844 adds the output of the limiter 843 to the positive correction amount Idc. Based on the previous value, output a positive correction amount Idc. The memory 845 maintains a positive correction value Idc. And as a positive correction quantity Idc The previous value is output to subtractor 846 and adder 844.

[0121] Through this structure, the second d-axis current command value generation unit 108C3 will generate a positive correction amount Idc. The difference between the previous value and the d-axis current command value after being limited by the upper limit value ΔI of the difference between the previous value and the d-axis current command value is ΔId. Add them together and use the sum as a positive correction value Idc. Output.

[0122] Therefore, when the voltage between the terminals of motor 5 is greater than the specified value, the second d-axis current command value generation unit 108C3 maintains a positive correction amount Idc. To make the positive correction amount Idc No increase. On the other hand, when the voltage between the terminals of motor 5 is below a specified value, the second d-axis current command value generation unit 108C3 generates a positive correction amount Idc. This makes it a positive correction value Idc With MTd axis current command value IdMT The difference ΔId between the d-axis current command values .

[0123] (A variation of Implementation Method 3)

[0124] Furthermore, as a variation of this embodiment, the upper limit calculation unit 841 of the second d-axis current command value generation unit 108C3 may also use the modulation rate difference ΔMa and the predetermined value ΔMconst of the modulation rate difference instead of the voltage difference ΔVa and the predetermined value ΔVconst of the voltage difference. That is, the upper limit calculation unit 841 may calculate the upper limit value ΔI of the d-axis current command value difference according to equation (9) when the modulation rate difference ΔMa is greater than or equal to the predetermined value ΔMconst, and output 0 when the modulation rate difference ΔMa is less than the predetermined value ΔMconst. Wherein, ΔMconst > 0.

[0125] In addition, such as Figure 15 As shown, the modulation rate difference ΔMa is the difference between 1 and the modulation rate Ma in the field weakening control unit 107C according to Embodiment 3. The generated value.

[0126] [Implementation Method 4]

[0127] In embodiment 4, the positive correction amount Idc during voltage phase control of motor 5 The generation process will be explained.

[0128] (Structure of the electric motor control device 100D according to Embodiment 4)

[0129] Figure 16 This is a structural diagram (rear section) of the motor control device 100D according to Embodiment 4. The motor control device 100D has the same structure as the motor control device 100 according to Embodiment 1. Figure 2A The same front section, but the rear section has Figure 16 The structure shown is used to replace Figure 2B The structure.

[0130] The motor control device 100D includes: a torque command value calculation unit 121, a voltage phase control unit 122, a flux command calculation unit 123, a flux estimation unit 124, an attenuation ratio control unit 125, a subtractor 126, and a rectangular wave generator 127.

[0131] Torque command value calculation unit 121 is based on d-axis current command value Id and q-axis current command value Iq The torque command value T is calculated based on the d-axis current detection value Idc and the q-axis current detection value Iqc. The torque T is output to the voltage phase control unit 122.

[0132] Specifically, the torque command value calculation unit 121 calculates the d-axis flux Φd and q-axis flux Φq based on the d-axis current detection value Idc and the q-axis current detection value Iqc, for example, by using a lookup table. Then, the torque command value calculation unit 121 calculates the torque T shown in equation (10). In the values ​​of the motor 5 in equation (10), P is the number of pole pairs, Φd is the d-axis flux, Φq is the q-axis flux, Idc is the d-axis current detection value, and Iqc is the q-axis current detection value.

[0133] T = 3 / 2 P(Φd) Iqc-Φq Idc) (10)

[0134] Furthermore, the torque command value calculation unit 121 is based on the d-axis current command value Id. and q-axis current command value Iq For example, the d-axis flux command value Φd can be calculated by looking up a table. q-axis flux command value Φq Then, the torque command value T shown in formula (11) of the torque command value calculation unit 121 is calculated. In the values ​​of motor 5 in equation (11), P is the number of pole pairs, and Φd Φq is the d-axis flux command value, and Id is the q-axis flux command value. Iq is the d-axis current command value. This is the q-axis current command value.

[0135] T** = 3 / 2 P(Φd*) Iq* - Φq* Id*) (11)

[0136] The voltage phase control unit 122 calculates the voltage phase angle θv to make the torque T match the torque command value T. The torque T is consistent with the torque command value T and output to the subtractor 126. Specifically, the voltage phase control unit 122 makes the torque T consistent with the torque command value T. The differential voltage is controlled by a PI controller (or I controller), and then limited by a limiter to output the voltage phase angle θv.

[0137] The flux command processing unit 123 uses the d-axis current command value Id and q-axis current command value Iq For example, referring to the lookup table, the d-axis flux command value Φd is output. and q-axis flux command value Φq The flux estimation unit 124 uses the d-axis current detection value Idc and the q-axis current detection value Iqc, for example, by referring to a lookup table, to estimate the d-axis flux estimation value Φdc and the q-axis flux estimation value Φqc. The attenuation ratio control unit 125 uses the d-axis flux command value Φdc. and q-axis flux command value Φq Using the d-axis flux estimate Φdc and the q-axis flux estimate Φqc, the phase angle correction θd is calculated to correct the voltage phase angle θv. This is to attenuate the vibrational component of the magnetic flux.

[0138] Subtractor 126 subtracts the phase angle correction θd from the voltage phase angle θv The voltage phase angle θv2 is then output to the rectangular wave generator 127. That is, the voltage phase angle θv is based on the phase angle correction amount θd. It has been corrected.

[0139] The rectangular wave generator 127 is based on the voltage phase angle θv2 and the magnetic pole position information θ The system generates pulse signals Su, Sv, and Sw corresponding to the voltage phase angle θv2 and outputs them to the power converter 10.

[0140] (Structure of the d-axis current command value correction unit 108D according to Embodiment 4)

[0141] Figure 17This is a diagram showing the structure of the d-axis current command value correction unit 108D according to Embodiment 4. The d-axis current command value correction unit 108D includes a subtractor 108D1 and an integrator 108D2.

[0142] The subtractor 108D1 calculates the d-axis current command value Id. The current difference ΔId between the previous value and the d-axis current detection value Idc is used. Based on the current difference ΔId, the integrator 108D2 generates and outputs a positive correction amount ΔIdc according to equation (12). .

[0143] ΔIdc*= ωfw×ΔId (12)

[0144] Here, ωfw is the cutoff frequency. When the current difference ΔId is multiplied by the cutoff frequency ωfw as the gain, the current error converges at the cutoff frequency ωfw. In this case, the positive correction ΔIdc... The response of the voltage phase control unit 122 must be slow enough to avoid interfering with the response of the torque control. For example, by setting the cutoff frequency of the voltage phase control unit 122 to a value more than three times greater than the cutoff frequency of the q-axis current command value generation unit 112, a positive correction amount ΔIdc is generated. The response is slow enough compared to the response of the voltage phase control unit 122.

[0145] [Implementation Method 5]

[0146] In implementation method 4, the d-axis current command value Id is used. The d-axis current detection value Idc generates a positive correction value Idc. In contrast, in implementation 4, the q-axis current command value Iq is used. The q-axis current detection value Iqc generates a positive correction value Idc. In this embodiment, the motor control device 100D includes a d-axis current command value correction unit 108E instead of the d-axis current command value correction unit 108.

[0147] (Structure of the d-axis current command value correction unit 108E according to Embodiment 5)

[0148] Figure 18 This diagram illustrates the structure of the d-axis current command value correction unit 108E according to Embodiment 5. The difference between the d-axis current command value correction unit 108E and the d-axis current command value correction unit 108D is that the d-axis current command value correction unit 108E is not based on the d-axis current command value Id. And the d-axis current detection value Idc, but based on the q-axis current command value Iq. The positive correction value ΔIdc is generated and output using the q-axis current detection value Iqc. .

[0149] The d-axis current command value correction unit 108E includes a subtractor 108E1 and an integrator 108E2. The subtractor 108E1 calculates the q-axis current command value Iq. The current difference ΔIq between the previous value and the q-axis current detection value Iqc is used by the integrator 108E2. Based on the current difference ΔIq, the integrator generates and outputs a positive correction amount ΔIdc using equation (13). Everything else is the same as in implementation method 4.

[0150] ΔIdc*= ωfw×ΔIq (13)

[0151] [Implementation Method 6]

[0152] In implementation method 4, the d-axis current command value Id is used. The d-axis current detection value Idc generates a positive correction value Idc. Furthermore, in embodiment 5, the d-axis current command value Id is used. The d-axis current detection value Idc generates a positive correction value Idc. In contrast, in embodiment 6, the d-axis current command value Id is used. and d-axis current detection value Idc, and d-axis current command value Id The positive correction value Idc is generated from both the d-axis current detection value and the d-axis current detection value Idc. .

[0153] (Structure of the motor control device 100F according to Embodiment 6)

[0154] Figure 19 This is a structural diagram (rear section) of the motor control device 100F according to Embodiment 6. The motor control device 100F has the same structure as the motor control device 100 according to Embodiment 1. Figure 2A The same front section, but the rear section has Figure 19 The structure shown is used to replace Figure 2B .

[0155] The motor control device 100F and the motor control device 100D according to Embodiment 4 ( Figure 16Compared to the former, the latter includes a second torque command value calculation unit 121F. Furthermore, although the example described is that the motor control device 100F does not have the flux command calculation unit 123, flux estimation unit 124, and attenuation ratio control unit 125 present in the motor control device 100D, the motor control device 100F may also have these structures.

[0156] The second torque command value calculation unit 121F is based on the d-axis current command value Id. and q-axis current command value Iq The second torque command value TR is calculated based on the d-axis current detection value Idc and the q-axis current detection value Iqc. The second torque TR is output to the voltage phase control unit 122F.

[0157] Specifically, the second torque command value calculation unit 121F is based on the d-axis current command value Id. and q-axis current command value Iq For example, the q-axis flux command value Φq can be calculated using a lookup table. The second torque command value calculation unit 121F calculates the q-axis flux command value Φq. Low-pass filtering is performed. The second torque command value calculation unit 121F processes the low-pass filtered q-axis flux command value Φq. With d-axis current command value Id Multiply and use as the second torque command value TR Output. Furthermore, the second torque command value calculation unit 121F will process the low-pass filtered q-axis flux command value Φq. The value is multiplied by the d-axis current detection value Idc and output as the second torque TR. The second torque command value calculation unit 121F, in order to reduce the torque margin in the high torque region, calculates the q-axis flux command value Φq. Multiply them to get a quantity of torque, but control is applied so that the d-axis current detection value Idc matches the d-axis current command value Id. Basically the same.

[0158] The voltage phase control unit 122F uses the torque command value T in the low torque region of the motor 5. The second torque command value TR is used in the high torque region of motor 5. It controls and outputs the voltage phase angle θv to make the torque command value consistent with the torque T of motor 5.

[0159] Specifically, the voltage phase control unit 122F compares the torque T with the torque command value T The difference is multiplied by the first gain. Furthermore, the voltage phase control unit 122F compares the second torque TR with the second torque command value TR. The difference is multiplied by the second gain. The voltage phase control unit 122F performs a torque command value T. The weighted average based on the torque command value T When the output torque T is less than the specified value, the torque command value T When the difference is above a specified value, the output torque TR is the second torque TR and the second torque command value TR. The difference. That is, in the high torque region, the second torque TR is used with respect to the second torque command value TR. The difference (hereinafter referred to as using the second torque) is used in the low torque region with torque T and torque command value T. The difference (hereinafter referred to as the first torque). The voltage phase control unit 122F outputs these weighted average ratios as Rate information to the d-axis current command value correction unit 108F, which will be described later.

[0160] The voltage phase control unit 122F inputs the weighted average output to the PI controller (or I controller). The PI controller (or I controller) performs amplitude limiting within the torque's peak value range and outputs the voltage phase angle θv. Alternatively, the torque T can be used as a reference for the aforementioned weighted average instead of the torque command value T. When the torque T is less than the specified value, the output is the second torque TR and the second torque command value TR. The difference, when the torque T is above a specified value, is the difference between the output torque T and the torque command value T. The difference.

[0161] (Structure of the d-axis current command value correction unit 108F according to Embodiment 6)

[0162] Figure 20 This is a diagram showing the structure of the d-axis current command value correction unit 108F according to Embodiment 6. Figure 17 In the d-axis current command value correction unit 108D shown, the d-axis current command value Id is calculated. Make the d-axis current command value Id It is consistent with the d-axis current detection value Idc. Furthermore, in Figure 18 In the d-axis current command value correction unit 108E shown, the q-axis current command value Iq is calculated. Make the q-axis current command value Iq It is consistent with the q-axis current detection value Iqc.

[0163] In contrast, Figure 20 In the d-axis current command value correction unit 108F shown, based on the Rate information output from the voltage phase control unit 122F, the d-axis current detection value Idc and the q-axis current detection value Iqc are weighted and averaged to obtain the d-axis current command value Id. This makes it consistent with the d-axis current command value Id. Consistent.

[0164] The subtractor 108F1 calculates the d-axis current command value Id. The current difference ΔId between the previous value and the d-axis current detection value Idc is calculated and output to the weighted average calculation unit 108F5 via the gain 108F2. The gain 108F2 is the cutoff frequency ωfw.

[0165] The subtractor 108F3 calculates the q-axis current command value Iq. The current difference ΔIq between the previous value and the q-axis current detection value Iqc is output to the weighted average calculation unit 108F5 via the gain 108F4. The gain 108F4 is Kfb as shown in equation (14). Regarding the values ​​of motor 5 in equation (14), ωfw is the cutoff frequency of field weakening control, Φm is the magnetic flux of the magnet, Ld is the d-axis inductance, Lq is the q-axis inductance, and Id It is the d-axis current command value, Iq It is the q-axis current command value.

[0166] Kfb=ωfw{Φm+(Ld-Lq)Id*} / {(Ld-Lq)Iq*} (14) Then, the d-axis current command value correction unit 108F, through the weighted average calculation unit 108F5 and the integrator 108F6, generates and outputs a positive correction amount Idc based on the current difference ΔId and ΔIq using equation (15). Regarding the values ​​of motor 5 in equation (15), Rate is the Rate information output by the voltage phase control unit 122F, Kfb is as shown in equation (14), Ld is the d-axis inductance, Lq is the q-axis inductance, and ωfw is the cutoff frequency of field weakening control.

[0167] Idc*= (Rate × Kfb × ΔIq + (1-Rate) × ωfw × ΔId) (15) Rate information is 0 in the low torque region, 1 in the high torque region, and in between, it takes a value between 0 and 1 depending on the torque.

[0168] Therefore, when the d-axis current command value correction unit 108F performs voltage phase control using the first torque, it uses the d-axis current difference ΔId for the d-axis current command value Id. For correction, when using the second torque for voltage phase control, the q-axis current difference ΔIq is used for the d-axis current command value Id. The correction. Regarding the second torque, it is actually controlled so that the d-axis current detection value Idc is equal to the d-axis current command value Id. Since the values ​​are consistent, the current difference ΔId is essentially zero and cannot be used for current correction. Therefore, for the d-axis current command value Id... For correction, it is best to use the current difference ΔIq of the q-axis current. On the other hand, as mentioned above, the effect is smaller in the low torque region when using the current difference ΔIq. Therefore, in the low torque region where the first torque is used, it is best to use the current difference ΔId for the d-axis current command value Id. Correction.

[0169] Effects of the Implementation Method

[0170] (1)

[0171] In Implementation 1, the d-axis current command value is generated based on the torque command value, and the q-axis current command value is generated based on the torque command value, the motor's magnet torque and reluctance torque, and the d-axis current command value. Since the d-axis and q-axis current command values ​​can be generated using a simple structure such as a reference two-dimensional mapping, torque accuracy can be ensured regardless of rotor temperature, DC voltage, and rotational speed (angular velocity). Furthermore, adaptation is easy, and the d-axis and q-axis current command values ​​can be generated quickly. In addition, the program size for generating the d-axis and q-axis current command values ​​can be reduced, improving program readability. Moreover, since the q-axis current command value is generated based on the torque formula of Equation (6), it always operates on the constant torque line even if the d-axis current command value is corrected, thus maintaining torque accuracy.

[0172] (2)

[0173] Furthermore, in Embodiment 1, either or both of the magnet torque and reluctance torque are corrected to generate a q-axis current command value. Using a simple structure with a two-dimensional mapping reference, a magnet torque gain to compensate for the magnet torque and a reluctance torque gain to compensate for the reluctance torque are generated, and a q-axis current command value is generated. Thus, the magnet torque gain and / or reluctance torque can be easily and quickly compensated.

[0174] (3)

[0175] Furthermore, in Embodiment 1, the magnet torque gain is generated using a simple structure based on a two-dimensional table reference between the torque command value or the q-axis current command value and the rotor temperature of the motor. This allows for easy and rapid compensation for variations in magnet torque relative to the torque command value or the q-axis current command value and the rotor temperature of the motor.

[0176] (4)

[0177] Furthermore, in Implementation 1, the reluctance torque gain is generated using a simple structure based on a two-dimensional table reference of torque command value or q-axis current command value and d-axis current command value. This allows for easy and rapid compensation of variations in the reluctance torque (inductance) relative to the torque command value or q-axis current command value and d-axis current command value.

[0178] (5)

[0179] Furthermore, in Implementation 1, the d-axis current command value is generated in a feedforward manner based on a simple structure using a two-dimensional mapping reference, using a flux limit value generated according to the torque command value and the DC voltage and angular velocity of the motor. This allows MTPA control and field weakening control to be implemented using a single table. Moreover, since temperature-induced torque variations are considered when generating the subsequent q-axis current command value, temperature-induced torque variations do not need to be considered when generating the d-axis current command value. Furthermore, this improves torque accuracy and responsiveness, as well as the voltage utilization efficiency of the motor.

[0180] (6)

[0181] Furthermore, in Embodiment 1, a negative correction amount is generated and applied to the d-axis current command value based on the target voltage and estimated voltage amplitude of the motor, so as to ensure that the voltage between the motor terminals does not exceed the maximum output voltage, and the d-axis current command value is corrected. Thus, field weakening control can be considered to correct the d-axis current command value generated by the feedforward method.

[0182] (7)

[0183] Furthermore, in Embodiment 1, when the voltage between the motor terminals is above a predetermined value, a positive correction amount is generated based on the modulation rate and applied to the d-axis current command value. This ensures that the field weakening control is always operational, driving the motor with minimal current.

[0184] (8)

[0185] Furthermore, in Embodiment 3, when the voltage between the motor terminals is less than a predetermined value, a positive correction amount is generated and applied to the d-axis current command value so that the d-axis current command value is close to the d-axis current on the MTPA (maximum torque / current) curve of the motor based on the torque command value. Thus, even if the rotor temperature rises, the motor can be driven with minimal current.

[0186] (9)

[0187] Furthermore, in embodiments 4 to 6, during voltage phase control, a positive correction amount is generated to correct the d-axis current command value based on either or both of the difference between the d-axis current command value and the d-axis current detection value, and the difference between the q-axis current command value and the q-axis current detection value of the motor, so that it is consistent with the d-axis current detection value. Therefore, during voltage phase control, the d-axis current detection value and the q-axis current detection value can follow the d-axis current command value and the q-axis current command value, respectively.

[0188] (10)

[0189] Furthermore, in Embodiment 1, a torque limit value is generated based on the flux limit value of the motor's DC voltage and angular velocity, which limits the torque command value, and the torque command value is limited based on the torque limit value. This enables the motor to operate within the MTPV (Max Torque Per Volt) region.

[0190] (11)

[0191] Furthermore, in Implementation 1, a drag torque compensation value is generated based on the DC voltage and flux limit value to compensate for the drag torque of the motor by adding it to the torque command value, and the drag torque compensation value is used to correct the torque command value. Thus, iron loss and mechanical loss not considered in Equation (6) are compensated, and the torque accuracy of the drag torque portion is prevented from decreasing.

[0192] (12)

[0193] Furthermore, in Implementation 1, a drag torque compensation value is generated based on the flux limit value under each DC voltage. Thus, mechanical losses and iron losses can be compensated for through simple linear interpolation of the DC voltage.

[0194] (13)

[0195] Furthermore, in Implementation 2, a drag torque compensation value is generated based on the angular velocity of the motor under each DC voltage. Both mechanical losses and iron losses can be compensated through linear interpolation of the DC voltage.

[0196] (14)

[0197] Furthermore, in a variation of Implementation 2, the drag torque compensation value is generated based on the angular velocity of the motor. This allows for compensation of mechanical losses. Moreover, control becomes easier when iron losses are negligible.

[0198] The embodiments of this application have been described in detail above, but the disclosure of this application is not limited to the above embodiments, and various modifications can be made without departing from its spirit. For example, the above embodiments are detailed descriptions provided for ease of understanding of the present invention, and the present invention is not necessarily limited to including all the structures described. In addition, some structures of the above embodiments may be added to, deleted from, or replaced with other structures.

[0199] Label Explanation

[0200] 1: Electric vehicle system; 5: Electric motor; 100, 100D, 100F: Electric motor control device; 101: Flux limit value generation unit; 102: Dragging torque compensation unit; 104: Torque limit value generation unit; 105: Torque command value limiting unit; 106: D-axis current command value generation unit; 107, 107C: Field weakening control unit; 108, 108C, 108D, 108E, 108F: D-axis current command value correction unit; 110: Magnet torque gain generation unit; 111: Reluctance torque gain generation unit; 112: Q-axis current command value generation unit; 122, 122F: Voltage phase control unit.

Claims

1. A motor control device that controls driving of a motor, characterized by, include: A d-axis current command value generation unit generates a d-axis current command value based on a torque command value. as well as The q-axis current command value generation unit generates the q-axis current command value based on the torque command value, the magnet torque and reluctance torque of the motor, and the d-axis current command value.

2. The motor control device as described in claim 1, characterized in that, The q-axis current command value generation unit corrects either or both of the magnet torque and the reluctance torque, and generates the q-axis current command value based on the magnet torque and the reluctance torque.

3. The motor control device as described in claim 2, characterized in that, It includes a magnet torque gain generation unit, which generates a magnet torque gain for correcting the magnet torque based on the torque command value or the q-axis current command value and the temperature of the motor. The q-axis current command value generation unit uses the magnet torque gain to correct the magnet torque.

4. The motor control device as described in claim 2, characterized in that, It includes a reluctance torque gain generation unit, which generates a reluctance torque gain for correcting the reluctance torque based on the torque command value or the q-axis current command value and the d-axis current command value. The q-axis current command value generation unit uses the reluctance torque gain to correct the reluctance torque.

5. The motor control device as described in claim 1, characterized in that, This includes a flux limit value generation unit that generates a flux limit value based on the DC voltage and angular velocity of the motor. The q-axis current command value generation unit generates the d-axis current command value based on the torque command value and the flux limit value.

6. The motor control device as described in claim 1, characterized in that, The system includes a field weakening control unit that generates a negative correction amount to be added to the d-axis current command value based on the target voltage and estimated voltage amplitude of the motor, and applies this negative correction amount to the d-axis current command value to ensure that the inter-terminal voltage of the motor does not exceed the maximum output voltage. The q-axis current command value generation unit generates the q-axis current command value based on the torque command value, the magnet torque and the reluctance torque, and the d-axis current command value after adding the negative correction amount.

7. The motor control device as described in claim 6, characterized in that, It includes a d-axis current command value correction unit, which generates a positive correction amount applied to the d-axis current command value when the inter-terminal voltage of the motor is above a specified value. The d-axis current command value correction unit calculates the modulation rate based on the voltage amplitude output from the voltage amplitude calculation unit and the DC voltage of the motor. The voltage amplitude calculation unit calculates the voltage amplitude output by the motor control device based on the d-axis voltage command value and the q-axis voltage command value. The d-axis voltage command value is adjusted so that the d-axis current detection value of the motor follows the d-axis current command value with both positive and negative corrections added. The q-axis voltage command value is adjusted so that the q-axis current of the motor follows the q-axis current command value. Set one or more reference modulation rates. The positive correction amount is generated based on the relationship between the modulation rate and the reference modulation rate.

8. The motor control device as described in claim 6, characterized in that, It includes a d-axis current command value correction unit, which generates a positive correction amount added to the d-axis current command value when the inter-terminal voltage of the motor is less than a specified value, so as to make the d-axis current command value close to the d-axis current on the MTPA (maximum torque / current) curve of the motor based on the torque command value.

9. The motor control device of claim 1, wherein include: A voltage phase control unit controls the voltage phase angle of the motor so that the torque of the motor matches the torque command value; as well as The d-axis current command value correction unit generates a positive correction amount to correct the d-axis current command value based on either or both of the difference between the d-axis current command value and the d-axis current detection value of the motor, and the difference between the q-axis current command value and the q-axis current detection value of the motor, so as to make it consistent with the d-axis current detection value.

10. The motor control device of claim 1, wherein include: A flux limit value generation unit generates a flux limit value based on the DC voltage and angular velocity of the motor. A torque limit value generation unit that generates a torque limit value that limits the torque command value based on the flux limit value; and A torque command value limiting unit that limits the torque command value based on the torque limit value.

11. The motor control device as described in claim 10, characterized in that, It includes a drag torque compensation unit, which generates a drag torque compensation value based on the DC voltage and the magnetic flux limit value, and adds it to the torque command value to compensate for the drag torque of the motor. The torque command value limiting unit limits the torque command value after the drag torque compensation value has been added, based on the torque limit value.

12. The motor control device as described in claim 11, characterized in that, The drag torque compensation unit generates the drag torque compensation value based on the magnetic flux limit value under each DC voltage.

13. The motor control device as described in claim 11, characterized in that, The drag torque compensation unit generates the drag torque compensation value based on the angular velocity of the motor under each DC voltage.

14. The motor control device as described in claim 11, characterized in that, The drag torque compensation unit generates the drag torque compensation value based on the angular velocity of the motor.

15. An electric vehicle, characterized by include: The motor control device as described in any one of claims 1 to 14; and The electric motor, The electric vehicle uses the electric motor as its drive source.

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