Control device for AC rotating motor

Abstract

The present invention provides a control device for an AC rotating electric machine capable of controlling the first and second axes by taking into account the interlinkage fluxes of the first and second axes, which vary with currents in the first and second axes, such as the d-axis and q-axis. The control device performs a standard response delay process on interlinkage flux command values ​​of the first and second axes, calculates standard response values ​​of the interlinkage fluxes of the first and second axes, and calculates voltage command values ​​for the first and second axes based on the standard response values ​​of the interlinkage fluxes of the first and second axes and the electrical angular velocity so as to feedforward vary the interlinkage fluxes of the first and second axes to the standard response values ​​of the interlinkage fluxes of the first and second axes.

Description

Technical Field

[0001] The present application relates to a control device for an AC rotating electrical machine. Background Art

[0002] Conventionally, a method for controlling AC rotating electric machines is known that calculates dq-axis voltage command values ​​using current command values ​​and the current's normalized response, rather than using acquired current values, in a rotating coordinate system for the dq axes. This method is referred to as current feedforward control. In current feedforward control, the dq-axis voltage command values ​​are calculated using the d-axis inductance Ld and the q-axis inductance Lq.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 4161064 Summary of the Invention

[0006] Technical problem to be solved by the invention

[0007] However, in rotating electrical machines that generate reluctance torque, there is a flux linkage component generated by the rotor core, which has nonlinear magnetic saturation characteristics. The d-axis flux linkage varies not only with the d-axis current but also with the q-axis current, and the q-axis flux linkage varies not only with the q-axis current but also with the d-axis current.

[0008] Therefore, in the method described in Patent Document 1, although the interlinkage flux of the d-axis that changes according to the current of the d-axis and the interlinkage flux of the q-axis that changes according to the current of the q-axis can be taken into account, the interlinkage flux of the d-axis that changes according to the current of the q-axis and the interlinkage flux of the q-axis that changes according to the current of the d-axis cannot be taken into account, and therefore there is a problem of reduced control accuracy.

[0009] Therefore, an object of the present application is to provide a control device for an AC rotating electric machine capable of performing control in consideration of the interlinkage magnetic fluxes of the first and second axes that change with each other according to the currents of the first and second axes, such as the d and q axes.

[0010] Technical means for solving technical problems

[0011] A first AC rotating electric machine control device according to the present application controls an AC rotating electric machine having an n-phase armature winding via an inverter, where n is a natural number greater than or equal to 2. The AC rotating electric machine control device includes:

[0012] a rotation detection unit that detects or estimates an electrical angle and an electrical angular velocity of a rotor of the AC rotating electric machine;

[0013] an interlinkage flux command calculation unit that calculates interlinkage flux command values ​​for a first axis and a second axis in a two-axis rotating coordinate system composed of a first axis and a second axis, the first axis and the second axis rotating in synchronization with the rotation of the rotor in terms of an electrical angle;

[0014] a cross-linkage flux standard response calculation unit configured to perform a standard response delay process on the cross-linkage flux command values ​​of the first axis and the second axis to calculate cross-linkage flux standard response values ​​of the first axis and the second axis;

[0015] a two-axis voltage command calculation unit that calculates voltage command values ​​for the first and second axes so as to feedforward-change the interlinkage fluxes of the first and second axes to the interlinkage flux standard response values ​​of the first and second axes based on the interlinkage flux standard response values ​​of the first and second axes and the electrical angular velocity;

[0016] an AC voltage command calculation unit that calculates an n-phase AC voltage command value, which is a voltage command value applied to the n-phase armature winding, based on the voltage command values ​​of the first and second axes and the electrical angle; and

[0017] A switching control unit performs on-off control of a plurality of switching elements included in the inverter based on the n-phase AC voltage command value.

[0018] A second AC rotating electric machine control device according to the present application controls an AC rotating electric machine having an n-phase armature winding via an inverter, where n is a natural number greater than or equal to 2. The AC rotating electric machine control device includes:

[0019] a rotation detection unit that detects or estimates an electrical angle and an electrical angular velocity of a rotor of the AC rotating electric machine;

[0020] a current command calculation unit that calculates current command values ​​for a first axis and a second axis in a two-axis coordinate system, i.e., a two-axis rotating coordinate system, the first axis and the second axis rotating in synchronization with the rotation of the rotor in terms of an electrical angle;

[0021] a current standard response calculation unit that performs standard response delay processing on the current command values ​​of the first axis and the second axis to calculate current standard response values ​​of the first axis and the second axis;

[0022] a two-axis voltage command calculation unit that calculates the standard response corresponding interlinkage fluxes of the first and second axes based on the standard response values ​​of the currents of the first and second axes, and calculates voltage command values ​​for the first and second axes on the rotating coordinate system of the two axes so as to feedforward change the currents of the first and second axes to the standard response values ​​of the currents of the first and second axes and the standard response corresponding interlinkage fluxes of the first and second axes, and the electrical angular velocity;

[0023] an AC voltage command calculation unit that calculates an n-phase AC voltage command value to be applied to the n-phase armature winding based on the voltage command values ​​of the first and second axes and the electrical angle; and

[0024] A switching control unit performs on-off control of a plurality of switching elements included in the inverter based on the n-phase AC voltage command value.

[0025] Effects of the Invention

[0026] According to the first AC rotating electric machine control device of the present application, when calculating the voltage command value that causes the interlinkage flux to change in a feedforward manner using a standard response, the standard response value of the interlinkage flux of the first and second axes, which varies linearly with time rather than with the currents of the first and second axes, is used. Therefore, the interlinkage flux of the first and second axes is not partially differentiated with the currents of the first and second axes, enabling linear system computation and suppressing an increase in the computational processing load. Furthermore, since the interlinkage flux is directly used, the nonlinear characteristics of the interlinkage flux of the first and second axes, which vary with the currents of the first and second axes, can be taken into account, thereby improving control accuracy.

[0027] According to the control device for the second AC rotating electric machine of the present application, the voltage command values ​​for the first and second axes are calculated based on the standard response values ​​of the currents of the first and second axes and the interlinkage flux corresponding to the standard response of the first and second axes, which is calculated based on the standard response values ​​of the currents of the first and second axes. This allows for linear system computation based on the standard response values ​​of the currents of the first and second axes, suppressing increases in computational processing load and improving computational accuracy. Furthermore, by using the standard response values ​​of the currents of the first and second axes and the interlinkage flux corresponding to the standard response of the first and second axes calculated based on the standard response values ​​of the currents of the first and second axes, the nonlinear characteristics of the interlinkage flux of the first and second axes that vary depending on the currents of the first and second axes can be taken into account, thereby improving control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic configuration diagram of an AC rotating electric machine and a control device for the AC rotating electric machine according to the first embodiment.

[0029] Figure 2 This is a schematic block diagram of a control device for an AC rotating electric machine according to the first embodiment.

[0030] Figure 3 This is a hardware configuration diagram of the control device for the AC rotating electric machine according to the first embodiment.

[0031] Figure 4 This is a block diagram of a two-axis voltage command calculation unit according to the first embodiment.

[0032] Figure 5 This is a block diagram of a two-axis voltage command calculation unit according to the first embodiment.

[0033] Figure 6 This is a block diagram of a two-axis voltage command calculation unit according to the first embodiment.

[0034] Figure 7 This is a flowchart illustrating the repetitive calculation of the standard response corresponding current values ​​of the dq axes according to the first embodiment.

[0035] Figure 8 This is a schematic block diagram of a control device for an AC rotating electric machine according to a second embodiment.

[0036] Figure 9 This is a block diagram of a two-axis voltage command calculation unit according to the second embodiment.

[0037] Figure 10 This is a block diagram of a two-axis voltage command calculation unit according to the second embodiment.

[0038] Figure 11 This is a block diagram of a two-axis voltage command calculation unit according to the second embodiment. DETAILED DESCRIPTION

[0039] 1. Implementation Method 1

[0040] A control device 1 for an AC rotating electrical machine according to a first embodiment (hereinafter simply referred to as a control device 1 ) will be described with reference to the drawings. Figure 1 It is a schematic configuration diagram of the AC rotating electric machine 2 and the control device 1 according to the present embodiment.

[0041] 1-1. AC rotating motor

[0042] The AC rotating motor 2 has an armature winding (hereinafter referred to as a winding) of n phases (n is a natural number greater than or equal to 2). The AC rotating motor 2 has a stator and a rotor. In this embodiment, n=3, and the three phases are U phase, V phase, and W phase. The stator is provided with three-phase windings Cu, Cv, and Cw. The three-phase windings Cu, Cv, and Cw are connected in a star configuration. Alternatively, the three-phase windings can be connected in a delta configuration. The stator is provided with permanent magnets, and is a permanent magnet type synchronous rotating motor. In this embodiment, the permanent magnets are embedded in the interior of the stator core formed of electromagnetic steel sheets.

[0043] The AC rotating electric machine 2 includes a rotation sensor 16 that outputs an electrical signal corresponding to the rotation angle of the rotor. The rotation sensor 16 is implemented as a Hall element, an encoder, a resolver, etc. The output signal of the rotation sensor 16 is input to the control device 1.

[0044] 1-2. Inverter, etc.

[0045] The inverter 20 performs power conversion between the DC power supply 10 and the three-phase windings and has multiple switching elements. The inverter 20 is provided with three series circuits (legs) corresponding to the windings of each of the three phases. These series circuits are connected in series with a positive-side switching element 23H (upper bridge arm) connected to the positive side of the DC power supply 10 and a negative-side switching element 23L (lower bridge arm) connected to the negative side of the DC power supply 10. The inverter 20 includes three positive-side switching elements 23H and three negative-side switching elements 23L, for a total of six switching elements. Furthermore, the connection point where the positive-side switching element 23H and the negative-side switching element 23L are connected in series is connected to the winding of the corresponding phase.

[0046] Specifically, in the series circuit of each phase, the collector terminal of the positive-side switching element 23H is connected to the positive-side wire 14, the emitter terminal of the positive-side switching element 23H is connected to the collector terminal of the negative-side switching element 23L, and the emitter terminal of the negative-side switching element 23L is connected to the negative-side wire 15. The connection point between the positive-side switching element 23H and the negative-side switching element 23L is connected to the winding of the corresponding phase. For the switching elements, an IGBT (Insulated Gate Bipolar Transistor) with a diode 22 connected in antiparallel, or a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) with the function of an antiparallel diode is used. The gate terminal of each switching element is connected to the control device 1. Each switching element is turned on or off by a control signal output from the control device 1.

[0047] The filter capacitor 12 is connected between the positive-side wire 14 and the negative-side wire 15. A power supply voltage sensor 13 is provided to detect the power supply voltage supplied from the DC power supply 10 to the inverter 20. The power supply voltage sensor 13 is connected between the positive-side wire 14 and the negative-side wire 15. The output signal of the power supply voltage sensor 13 is input to the control device 1.

[0048] A rechargeable power storage device (eg, a lithium-ion battery, a nickel-metal hydride battery, or an electric double-layer capacitor) is used as the DC power supply 10. The DC power supply 10 may also include a DC-DC converter that steps up or down a DC voltage.

[0049] 1-3. Control device 1

[0050] The control device 1 controls the AC rotating electric machine 2 via the inverter 20. Figure 2 As shown, the control device 1 includes a rotation detection unit 31, a voltage detection unit 32, an interlinkage flux command calculation unit 33, an interlinkage flux standard response calculation unit 34, a two-axis voltage command calculation unit 35, an AC voltage command calculation unit 36, and a switch control unit 37, which will be described later. The various functions of the control device 1 are implemented by the processing circuits provided by the control device 1. Specifically, the control device 1 is as follows. Figure 3 As shown, the processing circuit includes an arithmetic processing device 90 (computer) such as a CPU (Central Processing Unit), a storage device 91 for exchanging data with the arithmetic processing device 90, an input circuit 92 for inputting external signals to the arithmetic processing device 90, and an output circuit 93 for outputting signals from the arithmetic processing device 90 to the outside. The storage device 91, input circuit 92, and output circuit 93 are connected to the arithmetic processing device 90 via signal lines such as a bus.

[0051] The processing unit 90 may include an ASIC (Application Specific Integrated Circuit), an IC (Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), various logic circuits, and various signal processing circuits. Furthermore, the processing unit 90 may include multiple processing units of the same or different types to share the execution of various processes. The storage device 91 includes volatile and non-volatile storage devices such as RAM (Random Access Memory), ROM (Read Only Memory), and EEPROM (Electrically Erasable Programmable Read-Only Memory). The input circuit 92 is connected to various sensors and switches, such as the power supply voltage sensor 13 and the rotation sensor 16, and includes an A / D converter and other components that input the output signals of these sensors and switches to the processing unit 90. The output circuit 93 is connected to an electric load such as a gate drive circuit that drives the switching element on and off, and includes a drive circuit that outputs a control signal from the arithmetic processing device 90 to the electric load.

[0052] Furthermore, the control device 1 has Figure 2 The functions of each control unit 31-37, etc., are implemented by the arithmetic processing unit 90 executing software (programs) stored in a storage device 91, such as a ROM or EEPROM, in cooperation with other hardware components of the control unit 1, such as the storage device 91, the input circuit 92, and the output circuit 93. Furthermore, setting data such as the dq-axis current linkage flux characteristic data, the winding resistance value R, and the time constant Tr used by each control unit 31-37, etc., is stored as part of the software (programs) in the storage device 91, such as a ROM or EEPROM. The functions of the control unit 1 are described in detail below.

[0053] 1-3-1. Basic Control

[0054] The rotation detection unit 31 detects the rotor's electrical angle θ (magnetic pole position θ in this example) and electrical angular velocity ω. In this embodiment, the rotation detection unit 31 detects the rotor's magnetic pole position θ (electrical angle θ) and electrical angular velocity ω based on the output signal of the rotation sensor 16. In this embodiment, the magnetic pole position θ is set along the direction of the north pole of the permanent magnet provided on the rotor. Alternatively, the rotation detection unit 31 can be configured to estimate the rotor's electrical angle θ (magnetic pole position θ) based on current information obtained by superimposing higher harmonic components on the current command value, without using a rotation sensor (a so-called sensorless method).

[0055] The voltage detection unit 32 detects the power supply voltage VDC supplied from the DC power supply 10 to the inverter 20. In the present embodiment, the voltage detection unit 32 detects the power supply voltage VDC based on the output signal of the power supply voltage sensor 13.

[0056] The interlinkage flux command calculation unit 33 calculates interlinkage flux command values ​​for two axes on a two-axis rotating coordinate system consisting of a first axis and a second axis that rotate synchronously with the electrical angle of the rotor.

[0057] In this embodiment, a rotating coordinate system of the dq axes is used as a rotating coordinate system for the two axes. The rotating coordinate system of the dq axes is a rotating coordinate system of two axes consisting of the d axis, which is defined as the direction of the rotor's north pole (in this example, the direction of the magnetic pole position θ), and the q axis, which is defined as the direction of the electrical angle 90 degrees forward of the d axis. It rotates synchronously with the rotation of the rotor's north pole. The d axis corresponds to the first axis, and the q axis corresponds to the second axis. In addition, when using a sensorless method that estimates the electrical angle θ and the electrical angular velocity ω, a rotating coordinate system of the γβ axes that estimates the dq axes can also be used as a rotating coordinate system for the two axes. In this case, the d axis is replaced by the γ axis and the q axis is replaced by the β axis, and the processing itself described below does not change.

[0058] The interlinkage flux command calculation unit 33 calculates the d-axis interlinkage flux command value Ψdo and the q-axis interlinkage flux command value Ψqo in the dq-axis rotating coordinate system. In this embodiment, the interlinkage flux command calculation unit 33 calculates the dq-axis interlinkage flux command values ​​Ψdo and Ψqo based on the target torque, power supply voltage VDC, electrical angular velocity ω, and other parameters using current vector control methods such as maximum torque current control, flux weakening control, and Id=0 control. The target torque can be transmitted from an external device or calculated within the control device 1. In addition, the interlinkage flux command calculation unit 33 can directly calculate the interlinkage flux command values ​​Ψdo and Ψqo of the dq axes based on the target torque, etc., or the interlinkage flux command calculation unit 33 can also calculate the current command values ​​Ido and Iqo of the dq axes based on the target torque, etc., and refer to the current interlinkage flux characteristic data described later to calculate the interlinkage flux command values ​​Ψdo and Ψqo of the dq axes corresponding to the calculated current command values ​​Ido and Iqo of the dq axes.

[0059] The AC voltage command calculation unit 36 ​​calculates the voltage command values ​​applied to the three-phase windings, namely, the three-phase voltage command values ​​Vuo, Vvo, and Vwo, based on the dq-axis voltage command values ​​Vdo and Vqo and the electrical angle θ (magnetic pole position θ) calculated by the two-axis voltage command calculation unit 35 (described later). Specifically, the AC voltage command calculation unit 36 ​​performs fixed coordinate transformation and two-phase to three-phase transformation on the dq-axis voltage command values ​​Vdo and Vqo based on the magnetic pole position θ, converting them into the three-phase voltage command values ​​Vuo, Vvo, and Vwo. Furthermore, to improve voltage utilization, the three-phase voltage command values ​​may be subjected to known modulation methods such as space vector modulation and two-phase modulation.

[0060] The switching control unit 37 controls the on / off switching of the multiple switching elements included in the inverter 20 based on the three-phase voltage command values ​​Vuo, Vvo, and Vwo. For example, the switching control unit 37 compares the three-phase voltage command values ​​Vuo, Vvo, and Vwo with a carrier wave (a triangular wave) oscillating at a carrier frequency centered at zero with an amplitude equal to the power supply voltage VDC / 2. If the voltage command value exceeds the carrier wave, the PWM signal is turned on; if the voltage command value falls below the carrier wave, the rectangular pulse wave is turned off. Alternatively, space vector PWM can be used. The switching control unit 37 outputs control signals corresponding to the rectangular pulse waves for each of the three phases to the inverter 20, thereby turning the switching elements of the inverter 20 on and off.

[0061] 1-3-2. Interlinkage flux feedforward control

[0062] In the present embodiment, the two-axis voltage command calculation unit 35 is configured to perform interlinkage flux feedforward control for calculating dq-axis voltage command values ​​Vdo and Vqo based on dq-axis interlinkage flux command values ​​Ψdo and Ψqo.

[0063] 1-3-2-1. Issues with Current Feedforward Control

[0064] Voltage equation based on current

[0065] In conventional current feedback control, as shown in the following equation, a feedback control system is designed based on a linearized voltage equation regarding the dq-axis currents Id and Iq.

[0066] [Mathematical formula 1]

[0067]

[0068] Here, Vd is the d-axis voltage, Vq is the q-axis voltage, Id is the d-axis current, Iq is the q-axis current, ω is the rotor electrical angular velocity, R is the winding resistance, Ld is the d-axis inductance, Lq is the q-axis inductance, and Ψa is the cross-linkage flux generated by the permanent magnets.

[0069] <Existing current feedforward controller>

[0070] The conventional current feedforward controller described in equations (5) to (8) of Patent Document 1 designed based on equation (1) is as follows.

[0071] [Mathematical formula 2]

[0072]

[0073] In the conventional equation (2), the dq axis current standard response values ​​after the response delay processing of the standard response of the primary delay is performed on the dq axis current command values ​​Ido and Iqo are used. s is the Laplace operator, and Tr is the time constant of the primary delay.

[0074] <Problems Caused by the Mutual Dependence of Currents in the D and Q Axes of Linkage Flux>

[0075] However, in rotating electrical machines that generate reluctance torque, there is a flux linkage component generated by the rotor core (electromagnetic steel sheets), which has nonlinear magnetic saturation characteristics. Therefore, to be precise, the induced electromotive force generated by the change in flux linkage cannot be expressed as a linear equation, as shown in the second term on the right side of Equation (1), by multiplying the inductance of each axis by the change in current. Instead, a modeling error exists. Specifically, the d-axis flux linkage Ψd varies not only with the d-axis current Id but also with the q-axis current Iq. Meanwhile, the q-axis flux linkage Ψq varies not only with the q-axis current Iq but also with the d-axis current Id.

[0076] Therefore, as shown in formula (2), in the current feedforward control method using the d-axis inductance Ld and the q-axis inductance Lq, although the d-axis cross-linkage flux Ψd that changes according to the d-axis current Id and the q-axis cross-linkage flux Ψq that changes according to the q-axis current Iq can be taken into account, the d-axis cross-linkage flux Ψd that changes according to the q-axis current Iq and the q-axis cross-linkage flux Ψq that changes according to the d-axis current Id cannot be taken into account. Therefore, there is a problem of reduced control accuracy.

[0077] 1-3-2-1. Derivation of the interlinkage flux feedforward control system

[0078] <Voltage equation using dq-axis interlinkage flux>

[0079] Therefore, a control system is derived that takes into account the dq-axis interlinkage fluxes that change with each other depending on the dq-axis currents. If the voltage equation is directly expressed using the d-axis interlinkage flux Ψd and the q-axis interlinkage flux Ψq, the equation becomes as follows.

[0080] [Mathematical formula 3]

[0081]

[0082] Here, as described above, in a rotating electrical machine that generates reluctance torque, the d-axis interlinkage flux Ψd changes depending on the d-axis current Id and the q-axis current Iq. Therefore, the d-axis interlinkage flux Ψd becomes a function of the d-axis current Id and the q-axis current Iq (Ψd(Id, Iq)). Similarly, the q-axis interlinkage flux Ψq changes depending on the d-axis current Id and the q-axis current Iq. Therefore, the q-axis interlinkage flux Ψq becomes a function of the d-axis current Id and the q-axis current Iq (Ψq(Id, Iq)). The interlinkage flux Ψa generated by the permanent magnet in equation (1) is included in the d-axis interlinkage flux Ψd. Furthermore, the voltage drop caused by the winding resistance value R in the first term on the right side of equation (3) is not reflected in the interlinkage flux. Therefore, as in equation (1), the d- and q-axis currents Id and Iq are used. Therefore, the right side of equation (3) contains a mixture of current and interlinked magnetic flux.

[0083] Based on equation (3), the case of designing an interlinkage flux feedforward controller that calculates the dq-axis voltage command values ​​for changing the interlinkage flux of the dq axes in a feedforward manner with a standard response is discussed.

[0084] <Feedforward Controller According to Comparative Example>

[0085] As a comparative example, as shown in equations (4) and (5), as the dq axis currents Id and Iq in equation (3), the dq axis current standard response values ​​IdR and IqR after the response delay processing (in this example, a single delay) of the dq axis current command values ​​Ido and Iqo is considered, as in the existing method, and the dq axis voltage command values ​​Vdo and Vqo are calculated using feedforward control.

[0086] [Formula 4]

[0087]

[0088] [Formula 5]

[0089]

[0090] In this case, between the fully differential d / dt in the second term on the right side of equation (5) and the dq-axis current command values ​​Ido and Iqo in equation (4), there is a nonlinear function related to the dq-axis currents Id and Iq, namely, a function of the dq-axis interlinkage fluxes Ψd and Ψq. Therefore, it is impossible to switch the order of the differential operation and the calculation of the dq-axis interlinkage flux based on the dq-axis currents. To fully differentiate the dq-axis interlinkage fluxes Ψd and Ψq, which change according to the dq-axis currents, a linear approximation is required. This linear approximation partially differentiates the dq-axis interlinkage fluxes Ψd and Ψq with the d-axis current and then partially differentiates them with the q-axis current. The partial differential values ​​are then added together, which complicates the calculation. Furthermore, even if the standard response of the dq-axis current is delayed once, the standard response of the dq-axis interlinkage flux is not necessarily delayed once, and thus, the interlinkage flux cannot be changed with high precision using the standard response.

[0091] <Design of the Feedforward Controller According to the Present Embodiment>

[0092] Therefore, in this embodiment, as shown in equations (6) and (7), as the cross-linkage fluxes Ψd and Ψq of equation (3), the cross-linkage flux standard response values ​​ΨdR and ΨqR of the dq axes after the response delay processing (one-time delay in this example) of the standard response to the cross-linkage flux command values ​​Ψdo and Ψqo of the dq axes are considered, and the voltage command values ​​Vdo and Vqo of the dq axes are calculated using feedforward control.

[0093] [Formula 6]

[0094]

[0095] [Formula 7]

[0096]

[0097] In this case, the fully differentiated dq-axis cross-linkage flux standard response values ​​ΨdR and ΨqR do not change according to the dq-axis currents Id and Iq, but rather according to time t. Therefore, calculations can be performed using time differentiation rather than partial differentiation of the dq-axis currents. Furthermore, the time differential d / dt in the second term on the right side of Equation (7) can be replaced with the Laplace operator s, and the following equation, obtained by substituting it into Equation (6), can be combined with the response delay processing of the standard response (in this example, the first-order delay) to perform the calculation. This avoids the time differential calculation, and by studying the calculation by performing an equivalent conversion of the transfer function as shown in the second section of Equation (8), efficient calculations can be performed.

[0098] [Formula 8]

[0099]

[0100] When delaying the response of the standard response to the cross-linkage flux, as shown in the first term on the right side of equation (7), the dq-axis current values ​​IdcR and IqcR corresponding to the dq-axis cross-linkage flux standard response values ​​ΨdR and ΨqR (hereinafter referred to as dq-axis standard response corresponding current values ​​IdcR and IqcR) are used as the dq-axis currents. Details will be described later. The following equation holds between the dq-axis cross-linkage flux standard response values ​​ΨdR and ΨqR and the dq-axis standard response corresponding current values ​​IdcR and IqcR. Using this, the dq-axis standard response corresponding current values ​​IdcR and IqcR can be calculated.

[0101] [Formula 9]

[0102]

[0103] <Structure of the feedforward controller>

[0104] Therefore, the cross-linkage flux standard response calculation unit 34 performs a standard response delay process on the dq-axis cross-linkage flux command values ​​Ψdo and Ψqo to calculate the dq-axis cross-linkage flux standard response values ​​ΨdR and ΨqR. In this embodiment, as shown in equation (6), the cross-linkage flux standard response calculation unit 34 uses a first-order delay filtering process as the standard response delay process. Alternatively, various filtering processes such as a second-order delay filtering process may be used as the standard response delay process. In each equation, the Laplace operator s is used for representation, but the operator is discretized using a known method and incorporated into the control device 1.

[0105] Then, the two-axis voltage command calculation unit 35 calculates the dq-axis voltage command values ​​Vdo and Vqo that feedforward-change the dq-axis interlinkage fluxes Ψd and Ψq to the dq-axis interlinkage flux standard response values ​​ΨdR and ΨqR based on the dq-axis interlinkage flux standard response values ​​ΨdR and ΨqR and the electrical angular velocity ω.

[0106] According to this configuration, when calculating the voltage command value that feedforward-varies the interlinkage flux using the standard response, the linear dq-axis interlinkage flux standard response values ​​ΨdR and ΨqR, which vary with time rather than with the dq-axis currents, are used. Therefore, linear system computations such as time differentiation or a combination of time differentiation and response delay processing for the standard response can be performed without performing partial differentiation of the dq-axis interlinkage flux with the dq-axis currents, thereby suppressing increases in computational processing load. Furthermore, since the interlinkage flux is directly used, the influence of the nonlinear characteristics of the dq-axis interlinkage fluxes Ψd and Ψq, which vary with the dq-axis currents Id and Iq, can be avoided, thereby improving control accuracy.

[0107] Specifically, as shown in formula (7), the two-axis voltage command calculation unit 35 adds the time differential value of the d-axis cross-link flux standard response value ΨdR, the value obtained by multiplying the q-axis cross-link flux standard response value ΨqR by the electrical angular velocity ω and -1, and the d-axis current value corresponding to the dq-axis cross-link flux standard response value ΨdR and ΨqR, that is, the d-axis standard response corresponding current value IdcR multiplied by the winding resistance value R, to calculate the d-axis voltage command value Vdo. Furthermore, the two-axis voltage command calculation unit 35 calculates the q-axis voltage command value Vqo by adding the time differential value of the q-axis cross-linkage flux standard response value ΨqR, the value obtained by multiplying the d-axis cross-linkage flux standard response value ΨdR by the electrical angular velocity ω, and the value obtained by multiplying the q-axis current value corresponding to the dq-axis cross-linkage flux standard response values ​​ΨdR and ΨqR, that is, the q-axis standard response corresponding current value IqcR, by the winding resistance value R. The block diagram in this case is as follows: Figure 4 shown.

[0108] The details of the calculation process for the dq-axis standard response corresponding current values ​​IdcR and IqcR, which correspond to the dq-axis cross-linkage flux standard response values ​​ΨdR and ΨqR, will be described later. Furthermore, if the winding resistance value R is small and the first term on the right side of equation (7) is sufficiently small compared to the other terms, the calculation process for the winding resistance value R may not be performed. In this case, the repeated calculations described later are not performed, thereby reducing the computational processing load.

[0109] Alternatively, as shown in the first section of equation (8), the two-axis voltage command calculation unit 35 may also perform an operation on the dq-axis interlinkage flux command values ​​Ψdo and Ψqo by combining the time differential and the response delay processing of the standard response to calculate the time differential values ​​of the dq-axis interlinkage flux standard response values ​​ΨdR and ΨqR. In this case, the overall discretization of the combined transfer function may be performed, or equivalent conversion may be performed as shown in the second section of equation (8). The block diagram in this case is as follows: Figure 5 shown.

[0110] According to this configuration, it is possible to avoid performing time differentiation independently at the end, and to utilize the aggregated calculations to avoid excessive fluctuations in the calculated values ​​due to noise components and fluctuation components.

[0111] Alternatively, when the response delay processing of the standard response is a first-order delayed filtering process, as shown in the second paragraph of formula (8), the two-axis voltage command calculation unit 35 can also calculate the time differential value of the d-axis cross-link flux standard response value ΨdR by dividing the value obtained by subtracting the d-axis cross-link flux command value Ψdo from the d-axis cross-link flux command value ΨdR by the time constant Tr of the response delay processing of the standard response, and calculate the time differential value of the q-axis cross-link flux standard response value ΨqR by dividing the value obtained by subtracting the q-axis cross-link flux command value Ψqo from the q-axis cross-link flux command value Ψqo by the time constant Tr of the response delay processing of the standard response. The block diagram in this case is as follows. Figure 6 shown.

[0112] According to this structure, the time differential value of the cross-linkage flux standard response value of the dq axis can be calculated by using such a simple process as subtracting the cross-linkage flux instruction value of the dq axis from the cross-linkage flux instruction value. This can reduce the computational processing load and prevent excessive changes in the computational value due to noise components and variable components.

[0113] <Calculation of the dq-axis standard response corresponding current values ​​IdcR and IqcR>

[0114] The two-axis voltage command calculation unit 35 calculates the dq-axis standard response corresponding current values ​​IdcR and IqcR based on the dq-axis interlinkage flux standard response values ​​ΨdR and ΨqR.

[0115] As described above, equation (9) holds between the dq-axis cross-linkage flux standard response values ​​ΨdR and ΨqR and the dq-axis standard response corresponding current values ​​IdcR and IqcR. Using this, the dq-axis standard response corresponding current values ​​IdcR and IqcR can be calculated.

[0116] Therefore, the two-axis voltage command calculation unit 35 uses the d-axis current cross-linkage flux characteristic data Ψd (Id, Iq) with the dq-axis current values ​​Id and Iq as input values ​​and the d-axis cross-linkage flux Ψd as output value, and the q-axis current cross-linkage flux characteristic data Ψq (Id, Iq) with the dq-axis current values ​​Id and Iq as input values ​​and the q-axis cross-linkage flux Ψq as output value, and uses repeated calculations to search for the dq-axis standard response corresponding current values ​​IdcR and IqcR corresponding to the dq-axis cross-linkage flux standard response values ​​ΨdR and ΨqR.

[0117] This configuration takes into account the nonlinear characteristics of the dq-axis interlinkage fluxes Ψd and Ψq, which change according to the dq-axis currents Id and Iq. This improves the calculation accuracy of the dq-axis standard response corresponding current values ​​IdcR and IqcR, thereby enhancing control accuracy. Furthermore, since characteristic data other than the dq-axis current interlinkage flux characteristic data is not used, an increase in the storage capacity of the storage device 91 can be suppressed.

[0118] Various methods, such as Newton's method, can be used for iterative calculations. However, using methods like Newton's method that utilize gradient information to converge to the optimal solution requires characteristic data and calculations for the gradient information of the dq-axis interlinkage flux with respect to the dq-axis current values, which complicates the calculation process. Therefore, iterative calculations that do not utilize gradient information of the interlinkage flux with respect to the current values, such as the Nelder-Mead method, can also be used.

[0119] Map data or a high-order function (eg, a polynomial, a neural network) is used as the current linkage flux characteristic data of the d-axis and q-axis, and is stored in advance in a storage device 91 such as a ROM or an EEPROM.

[0120] Specifically, if Figure 7As shown in the flowchart, in step S01, the two-axis voltage command calculation unit 35 sets the initial values ​​of the candidate values ​​IdcRc and IqcRc for the current dq-axis standard response corresponding current values. The dq-axis standard response corresponding current values ​​IdcR and IqcR continuously change with a response delay equivalent to the response delay of the standard response. Thus, the previously searched dq-axis standard response corresponding current values ​​IdcR and IqcR can be set as the initial values ​​of the candidate values ​​IdcRc and IqcRc for the current dq-axis standard response corresponding current values. This reduces the number of iterations and the computational load. Furthermore, since the dq-axis standard response corresponding current values ​​IdcR and IqcR change with the response delay of the standard response, the difference between the previously searched values ​​and the current searched values ​​does not increase, thus reducing the number of iterations.

[0121] Then, in step S02, the two-axis voltage command calculation unit 35 refers to the current interlinkage flux characteristic data of the d-axis and q-axis to calculate the candidate value Ψdc of the d-axis interlinkage flux and the candidate value Ψqc of the q-axis interlinkage flux corresponding to the candidate values ​​IdcRc and IqcRc of the current values ​​corresponding to the current standard response of the current dq axes.

[0122] Then, in step S03, if the candidate values ​​Ψdc and Ψqc of the d-axis and q-axis interlinkage fluxes calculated in step S02 are sufficiently close to the d-axis and q-axis interlinkage flux standard response values ​​ΨdR and ΨqR (for example, if the residual norm Nrm is equal to or less than the determination value), or if the number of iterations has reached the upper limit, the two-axis voltage command calculation unit 35 proceeds to step S05 to terminate the iterative calculation. Otherwise, the two-axis voltage command calculation unit 35 proceeds to step S04 to continue the iterative calculation. As shown in the following equation, the residual norm Nrm is the sum of the square of the deviation between the candidate value Ψdc of the d-axis interlinkage flux and the standard response value ΨdR of the d-axis interlinkage flux, and the square of the deviation between the candidate value Ψqc of the q-axis interlinkage flux and the standard response value ΨqR of the q-axis interlinkage flux.

[0123] [Formula 10]

[0124] Nrm=(Ψ dc -Ψ dR ) 2 +(Ψ qc -Ψ qR ) 2 ...(10)

[0125] In step S04, the two-axis voltage command calculation unit 35 changes the candidate values ​​IdcRc and IqcRc for the d-axis and q-axis standard response corresponding current values ​​based on the candidate values ​​Ψdc and Ψqc of the d-axis interlinkage flux calculated in step S02, and then returns to step S02. Various methods, such as the Newton method and the Nelder-Mead method, can be used to change the candidate values. Since these methods are well known, their description will be omitted.

[0126] Meanwhile, in step S05 , the two-axis voltage command calculation unit 35 calculates the current dq axis standard response corresponding current value candidate values ​​IdcRc and IqcRc as the final dq axis standard response corresponding current values ​​IdcR and IqcR, and ends the process.

[0127] Alternatively, the two-axis voltage command calculation unit 35 can also refer to the d-axis cross-linkage flux current characteristic data Id (Ψd, Ψq) with the dq-axis cross-linkage flux Ψd, Ψq as input values ​​and the d-axis current value Id as output value, and the q-axis cross-linkage flux current characteristic data Iq (Ψd, Ψq) with the dq-axis cross-linkage flux Ψd, Ψq as input values ​​and the q-axis current value Iq as output value, to calculate the dq-axis standard response corresponding current values ​​IdcR, IqcR corresponding to the dq-axis cross-linkage flux standard response values ​​ΨdR, ΨqR.

[0128] This configuration takes into account the nonlinear characteristics of the dq-axis interlinkage fluxes Ψd and Ψq, which vary depending on the dq-axis currents Id and Iq. This improves the calculation accuracy of the dq-axis standard response corresponding current values ​​IdcR and IqcR, thereby enhancing control accuracy. While dq-axis interlinkage flux current characteristic data, which is the inverse of the dq-axis current interlinkage flux characteristic data, must be pre-set and stored in the storage device 91, repeated calculations are eliminated, significantly reducing the computational processing load.

[0129] Map data or a high-order function (eg, a polynomial, a neural network) is used as the d-axis and q-axis interlinkage flux current characteristic data, and is stored in advance in a storage device 91 such as a ROM or an EEPROM.

[0130] Summary and application examples

[0131] As described above, the dq-axis voltage command values ​​Vdo and Vqo, which cause the dq-axis interlinkage fluxes Ψd and Ψq to be feedforward-varied, are calculated based on the dq-axis interlinkage flux standard response values ​​ΨdR and ΨqR. Consequently, in the absence of disturbances and modeling errors, the dq-axis interlinkage flux and dq-axis current values ​​can be varied according to the standard response. Furthermore, the torque generated by the dq-axis interlinkage flux and dq-axis current values ​​also achieves a desired response close to the standard response.

[0132] In this feedforward controller, a current sensor is not required, thus reducing the cost associated with the current sensor. Furthermore, the current value detected by the current sensor is not used for control, thus eliminating the effects of delays and noise that may occur in the detected current value.

[0133] Alternatively, current sensors may be provided to detect the current flowing through the three-phase windings, and feedback control may be performed based on the current detection values. In this case, the dq-axis voltage command values ​​Vdofb and Vqofb generated by the feedback control are added to the dq-axis voltage command values ​​Vdo and Vqo generated by the feedforward control to calculate the final dq-axis voltage command values ​​Vdo and Vqo. As feedback control, the control device 1 performs a three-phase to two-phase conversion and a rotational coordinate conversion on the three-phase current detection values ​​Iur, Ivr, and Iwr based on the magnetic pole position θ to calculate the dq-axis current detection values ​​Idr and Iqr. The control device then changes the dq-axis feedback voltage command values ​​Vdofb and Vqofb so that the dq-axis current detection values ​​Idr and Iqr approach the dq-axis standard response corresponding current values ​​IdcR and IqcR. Alternatively, similar to Japanese Patent No. 6687228, control device 1 utilizes dq-axis current interlinkage flux characteristic data to calculate dq-axis interlinkage flux detection values ​​Ψdr and Ψqr based on the dq-axis current detection values ​​Idr and Iqr. The control device then varies the dq-axis feedback voltage command values ​​Vdofb and Vqofb to bring the dq-axis interlinkage flux detection values ​​Ψdr and Ψqr closer to the dq-axis interlinkage flux standard response values ​​ΨdR and ΨqR. Incorporating feedback improves robustness against disturbances and modeling errors. Alternatively, other components, such as high-frequency components, may be added to the dq-axis voltage command values ​​Vdo and Vqo.

[0134] 2. Implementation Method 2

[0135] Next, the control device 1 involved in the second embodiment is described. The description of the same structural parts as those in the above-mentioned first embodiment is omitted. The basic structure and processing of the AC rotating motor 2 and the control device 1 involved in this embodiment are the same as those in the first embodiment. In the first embodiment, the interlinkage flux feedforward controller is designed, and the interlinkage flux feedforward controller calculates the voltage command values ​​Vdo and Vqo of the dq axes so as to feedforward change the interlinkage fluxes Ψd and Ψq of the dq axes with a standard response. However, in this embodiment, the current feedforward controller described as a comparative example in the first embodiment is designed, and the current feedforward controller calculates the voltage command values ​​Vdo and Vqo of the dq axes so as to feedforward change the current values ​​Id and Iq of the dq axes with a standard response.

[0136] In this embodiment, if Figure 8 As shown in the block diagram, the interlinkage flux command calculation unit 33 of the first embodiment is changed to a current command calculation unit 38, the interlinkage flux standard response calculation unit 34 is changed to a current standard response calculation unit 39, and the structure of the two-axis voltage command calculation unit 35 is different from that of the first embodiment.

[0137] <Current Command Calculation Unit 38>

[0138] The current command calculation unit 38 calculates the d-axis current command value Ido and the q-axis current command value Iqo in the dq-axis rotating coordinate system. In this embodiment, the current command calculation unit 38 calculates the dq-axis current command values ​​Ido and Iqo based on the target torque, power supply voltage VDC, electrical angular velocity ω, and other factors using current vector control methods such as maximum torque current control, flux weakening control, and Id=0 control. The target torque can be transmitted from an external device or calculated within the control device 1.

[0139] <Current standard response calculation unit 39>

[0140] The current standard response calculation unit 39 performs standard response delay processing on the d / q axis current command values ​​Ido and Iqo to calculate the d / q axis current standard response values ​​IdR and IqR. In this embodiment, as shown in the following equation, which is the same as equation (4), the current standard response calculation unit 39 uses a first-order delay filtering process as the standard response delay processing. Alternatively, various filtering processes, such as a second-order delay filtering process, may be used as the standard response delay processing.

[0141] [Mathematical formula 11]

[0142]

[0143] <Design of the Feedforward Controller According to the Present Embodiment>

[0144] The dq-axis linkage fluxes Ψd and Ψq in the second term on the right side of Equation (5) are nonlinear functions related to the dq-axis currents Id and Iq, and therefore cannot be directly differentiated in time. Therefore, as shown in the following equation, it is necessary to perform a linear approximation on the linkage fluxes Ψd and Ψq in the second term on the right side of Equation (5). This linear approximation performs a partial differentiation of the d-axis current standard response value IdR and the q-axis current standard response value IqR, and then adds them together.

[0145] [Mathematical formula 12]

[0146]

[0147] The partial differentials of formula (12) are as follows.

[0148] [Mathematical formula 13]

[0149]

[0150] The terms on the right side of equation (13) are called differential inductances. Like the dq-axis linkage fluxes Ψd and Ψq, differential inductances are functions of the d-axis current Id and the q-axis current Iq. Substituting equations (12) and (13) into equation (5) yields the following voltage equation using the four differential inductances Ldd, Ldq, Lqd, and Lqq. While this requires preparing characteristic data for the four differential inductances, it can suppress increases in computational load. Furthermore, the dq-axis currents can be varied with high precision, maintaining a standard response.

[0151] [Mathematical formula 14]

[0152]

[0153] In this case, the dq-axis current standard response values ​​IdR and IqR change with time, so time differentiation can be performed. Furthermore, the time differential d / dt in the second term on the right side of Equation (14) can be replaced with the Laplace operator s. Substituting this into Equation (11) yields the following equation. This allows the differential operation to be combined with the response delay processing (primary delay in this example) of the standard response to perform the calculation. This avoids the need for time differentiation. Furthermore, by performing an equivalent transfer function conversion and studying the calculation as shown in the second section of Equation (15), efficient calculations can be performed.

[0154] [Mathematical formula 15]

[0155]

[0156] <Structure of the feedforward controller>

[0157] Therefore, in this embodiment, corresponding to the third term on the right side of equation (14), the two-axis voltage command calculation unit 35 calculates the dq axis standard response corresponding interlinkage fluxes ΨdcR and ΨqcR based on the dq axis current standard response values ​​IdR and IqR.

[0158] In this embodiment, the two-axis voltage command calculation unit 35 refers to the d-axis current cross-linkage flux characteristic data Ψd(Id, Iq) with the dq-axis current values ​​Id and Iq as input values ​​and the d-axis cross-linkage flux Ψd as output value, and the q-axis current cross-linkage flux characteristic data Ψq(Id, Iq) with the dq-axis current values ​​Id and Iq as input values ​​and the q-axis cross-linkage flux Ψq as output value, to calculate the dq-axis cross-linkage flux corresponding to the dq-axis current standard response values ​​IdR and IqR, that is, the dq-axis standard response corresponding cross-linkage flux ΨdcR and ΨqcR.

[0159] [Mathematical formula 16]

[0160]

[0161] As described above, map data or high-order functions (eg, polynomials, neural networks) are used as the current linkage flux characteristic data of the d-axis and q-axis, and are stored in advance in the storage device 91 such as a ROM or EEPROM.

[0162] The two-axis voltage command calculation unit 35 calculates the dq-axis standard response corresponding interlinkage fluxes ΨdcR and ΨqcR based on the dq-axis current standard response values ​​IdR and IqR. Based on the dq-axis current standard response values ​​IdR and IqR, the dq-axis standard response corresponding interlinkage fluxes ΨdcR and ΨqcR, and the electrical angular velocity ω, the two-axis voltage command calculation unit 35 calculates the dq-axis voltage command values ​​Vdo and Vqo on the dq-axis rotating coordinate system that causes the dq-axis currents Id and Iq to feedforward change to the dq-axis current standard response values ​​IdR and IqR.

[0163] This configuration calculates the dq-axis voltage command values ​​Vdo and Vqo based on the dq-axis current standard response values ​​IdR and IqR, and the dq-axis standard response corresponding interlinkage fluxes ΨdcR and ΨqcR calculated based on these values. This allows for linear system computation based on the dq-axis current standard response values ​​IdR and IqR, suppressing increases in computational processing load associated with time differentiation or calculations combining time differentiation with response delay processing for the standard response, while improving computational accuracy. Furthermore, using the dq-axis current standard response values ​​IdR and IqR allows the dq-axis currents to be varied with high precision based on the standard response.

[0164] Specifically, as shown in formula (14), the two-axis voltage command calculation unit 35 calculates the d-axis voltage command value Vdo by adding the d-axis current differential d-axis inductance Ldd obtained by partially differentiating the d-axis cross-linked magnetic flux with the d-axis current by the time differential value of the d-axis current standard response value IdR, the q-axis current differential d-axis inductance Ldq obtained by partially differentiating the d-axis cross-linked magnetic flux with the q-axis current by the time differential value of the q-axis current standard response value IqR, the q-axis standard response corresponding cross-linked magnetic flux ΨqcR multiplied by the electrical angular velocity ω and -1, and the d-axis current standard response value IdR multiplied by the winding resistance value R. In addition, the two-axis voltage command calculation unit 35 calculates the q-axis voltage command value Vqo by adding the value obtained by multiplying the d-axis current differential q-axis inductance Lqd obtained by partial differentiation of the q-axis interlinkage flux with the d-axis current by the time differential value of the d-axis current standard response value IdR, the value obtained by multiplying the q-axis current differential q-axis inductance Lqq obtained by partial differentiation of the q-axis interlinkage flux with the q-axis current by the time differential value of the q-axis current standard response value IqR, the value obtained by multiplying the d-axis standard response corresponding interlinkage flux ΨdcR by the electrical angular velocity ω, and the value obtained by multiplying the q-axis current standard response value IqR by the winding resistance value R. The block diagram in this case is as follows: Figure 9 shown.

[0165] In addition, when the winding resistance value R is small and the term of the winding resistance value R in the first term on the right side of formula (14) is sufficiently small compared with other terms, the calculation processing of the term of the winding resistance value R can be omitted.

[0166] In this embodiment, as shown in formula (13), the two-axis voltage command calculation unit 35 refers to the d-axis current differential d-axis inductance characteristic data Ldd (Id, Iq) with the dq-axis current values ​​Id and Iq as input values ​​and the d-axis current differential d-axis inductance Ldd as the output value, the q-axis current differential d-axis inductance characteristic data Ldq (Id, Iq) with the dq-axis current values ​​Id and Iq as input values ​​and the q-axis current differential d-axis inductance Ldq as the output value, and the dq-axis current differential d-axis inductance characteristic data Ldq (Id, Iq) with the dq-axis current values ​​Id and Iq as input values ​​and the d-axis current differential q-axis inductance Ldq as the output value. The d-axis current differential q-axis inductance characteristic data Lqd(Id, Iq) with Lqd as the output value, and the q-axis current differential q-axis inductance characteristic data Lqq(Id, Iq) with the dq-axis current values ​​Id and Iq as input values ​​and the q-axis current differential q-axis inductance Lqq as the output value, are used to calculate the d-axis current differential d-axis inductance Ldd, the q-axis current differential d-axis inductance Ldq, the d-axis current differential q-axis inductance Lqd, and the q-axis current differential q-axis inductance Lqq corresponding to the dq-axis current standard response values ​​IdR and IqR.

[0167] Mapping data or high-order functions (such as polynomials, neural networks, etc.) are used as d-axis current differential d-axis inductance characteristic data, q-axis current differential d-axis inductance characteristic data, d-axis current differential q-axis inductance characteristic data, and q-axis current differential q-axis inductance characteristic data, and are pre-stored in a storage device 91 such as ROM or EEPROM.

[0168] Alternatively, as shown in the first paragraph of formula (15), the two-axis voltage command calculation unit 35 can also perform an operation on the dq axis current command values ​​Ido and Iqo by summarizing the time differential and the response delay processing of the standard response to calculate the time differential value of the dq axis current standard response value IdR and IqR. In this case, the entire summarized transfer function can be discretized or equivalently converted as shown in the example of the second paragraph of formula (15). The block diagram in this case is as follows Figure 10 shown.

[0169] According to this configuration, it is possible to avoid performing time differentiation independently at the end, and to utilize the aggregated calculations to avoid excessive fluctuations in the calculated values ​​due to noise components and fluctuation components.

[0170] Alternatively, in the case where the response delay processing of the standard response is a first-order delayed filtering process, as shown in the second paragraph of formula (15), the two-axis voltage command calculation unit 35 may also calculate the time differential value of the d-axis current standard response value IdR by dividing the value obtained by subtracting the d-axis current standard response value IdR from the d-axis current command value Ido by the time constant Tr of the response delay processing of the standard response, and calculate the time differential value of the q-axis current standard response value IqR by dividing the value obtained by subtracting the q-axis current standard response value IqR from the q-axis current command value Iqo by the time constant Tr of the response delay processing of the standard response. The block diagram in this case is as follows: Figure 11 shown.

[0171] According to this structure, the time differential value of the dq-axis current standard response value can be calculated by a simple process of subtracting the dq-axis current standard response value from the dq-axis current command value, which can reduce the calculation processing load and prevent excessive fluctuations in the calculation value due to noise components and variation components.

[0172] Summary and application examples

[0173] As described above, the dq-axis voltage command values ​​Vdo and Vqo, which feedforward vary the dq-axis current values ​​Id and Iq, are calculated based on the dq-axis current standard response values ​​IdR and IqR. This allows the dq-axis current values ​​and the dq-axis interlinkage flux to vary according to the standard response, absent interference or modeling errors. Furthermore, the torque generated by the dq-axis current values ​​and the dq-axis interlinkage flux achieves a desired response close to the standard response.

[0174] In this feedforward controller, a current sensor is not required, thus reducing the cost associated with the current sensor. Furthermore, the current value detected by the current sensor is not used for control, thus eliminating the effects of delays and noise that may occur in the detected current value.

[0175] Alternatively, current sensors may be provided to detect the current flowing through the three-phase windings, and feedback control may be performed based on the current detection values. In this case, the dq-axis voltage command values ​​Vdofb and Vqofb generated by the feedback control are added to the dq-axis voltage command values ​​Vdo and Vqo generated by the feedforward control to calculate the final dq-axis voltage command values ​​Vdo and Vqo. As feedback control, the control device 1 performs a three-phase to two-phase conversion and a rotational coordinate conversion on the three-phase current detection values ​​Iur, Ivr, and Iwr based on the magnetic pole position θ to calculate the dq-axis current detection values ​​Idr and Iqr. The control device then varies the dq-axis feedback voltage command values ​​Vdofb and Vqofb so that the dq-axis current detection values ​​Idr and Iqr approach the dq-axis current standard response values ​​IdR and IqR. Alternatively, similar to Japanese Patent No. 6687228, control device 1 utilizes dq-axis current interlinkage flux characteristic data to calculate dq-axis interlinkage flux detection values ​​Ψdr and Ψqr based on the dq-axis current detection values ​​Idr and Iqr. The control device then varies the dq-axis feedback voltage command values ​​Vdofb and Vqofb to bring the dq-axis interlinkage flux detection values ​​Ψdr and Ψqr closer to the dq-axis standard response corresponding interlinkage flux values ​​ΨdcR and ΨqcR. Incorporating feedback improves robustness against disturbances and modeling errors. Alternatively, other components, such as high-frequency components, may be added to the dq-axis voltage command values ​​Vdo and Vqo.

[0176] [Other embodiments]

[0177] Finally, other embodiments of the present application will be described. In addition, the structures of the embodiments described below are not limited to being applied individually, and can be applied in combination with the structures of other embodiments as long as no contradiction occurs.

[0178] (1) In the above embodiments, the three-phase case where n = 3 is described as an example. However, n may be set to any natural number greater than 2, such as n = 2 or 4.

[0179] (2) The above embodiments describe a case where a single set of three-phase windings and inverters is provided. However, two or more sets of three-phase windings and inverters may be provided, and each set of three-phase windings and inverters may be controlled in the same manner as in the above embodiments. In this case, a term that takes into account inter-set interference may be added to the calculation of the dq-axis voltage command values ​​Vdo and Vqo.

[0180] (3) In each of the above embodiments, the case of an embedded magnet type synchronous AC rotating motor is described as an example. However, it may also be a reluctance type synchronous AC rotating motor or an excitation winding type synchronous AC rotating motor. Alternatively, it may be a surface magnet type AC rotating motor. In the case of the surface magnet type, the mutual dependence of the currents of the dq axes of the interlinked magnetic flux is low, but sometimes it may not be zero. As in the above embodiments, the control accuracy can be improved by taking into account the mutual dependence of the currents of the dq axes of the interlinked magnetic flux. In addition, in the same discussion as in Patent Document 1, the control of the present application can also be applied to induction motors.

[0181] (4) In the above embodiments, the change in the relationship between the current and the interlinkage flux due to changes in the magnet temperature is not considered. However, it is also possible to consider the change in the relationship between the current and the interlinkage flux due to changes in the magnet temperature by estimating the change in the interlinkage flux due to temperature or storing it in advance as characteristic data in a storage device and adding the change in the interlinkage flux to the current during the interlinkage flux conversion.

[0182] (5) In the above embodiments, the case where a first-order delay filter is used as the standard response is described as an example. However, various filters may be used as the standard response, and a second-order delay filter may be used as shown in the following equation.

[0183] [Mathematical formula 17]

[0184]

[0185] In such a case, as shown in the second section of equation (8) and the second section of equation (15) for the first-order delay filter, since it is impossible to perform equivalent conversion of the transfer function and replace it with an algebraic operation, it is also possible to combine the differential operation and the response delay processing of the standard response (in this example, the second-order delay) to perform the operation to perform the operation on each time differential as shown in the following equation.

[0186] [Mathematical formula 18]

[0187]

[0188] When using a quadratic delay filter, unlike a linear delay filter, the rate of change of the step response at t = 0 is zero, making the rate of change of torque, i.e., the rate of change of acceleration (jerk), more continuous. Therefore, when this structure is used in vehicles, discontinuous changes in jerkiness can be further suppressed, thus minimizing the deterioration of the ride quality.

[0189] Although this application describes various exemplary embodiments and examples, the various features, methods, and functions described in one or more embodiments are not limited to the application of specific embodiments and can be applied to the embodiments individually or in various combinations. Therefore, it can be considered that countless variations not illustrated are also included in the technical scope disclosed in this application specification. For example, it is set to include the case where at least one component is deformed, added, or omitted, and the case where at least one component is extracted and combined with the components of other embodiments.

Claims

1. A control device for an AC rotating electric machine, the control device for an AC rotating electric machine controlling an AC rotating electric machine having an n-phase armature winding via an inverter, where n is a natural number greater than or equal to 2, the control device comprising: a rotation detection unit that detects or estimates an electrical angle and an electrical angular velocity of a rotor of the AC rotating electric machine; an interlinkage flux command calculation unit that calculates interlinkage flux command values ​​for a first axis and a second axis in a two-axis rotating coordinate system composed of a first axis and a second axis, the first axis and the second axis rotating in synchronization with the rotation of the rotor in terms of an electrical angle; a cross-linkage flux standard response calculation unit configured to perform a standard response delay process on the cross-linkage flux command values ​​of the first axis and the second axis to calculate cross-linkage flux standard response values ​​of the first axis and the second axis; a two-axis voltage command calculation unit that calculates voltage command values ​​for the first and second axes so as to feedforward-change the interlinkage fluxes of the first and second axes to the interlinkage flux standard response values ​​of the first and second axes based on the interlinkage flux standard response values ​​of the first and second axes and the electrical angular velocity; an AC voltage command calculation unit that calculates an n-phase AC voltage command value, which is a voltage command value applied to the n-phase armature winding, based on the voltage command values ​​of the first and second axes and the electrical angle; and A switching control unit performs on-off control of a plurality of switching elements included in the inverter based on the n-phase AC voltage command value.

2. The control device for an AC rotating electrical machine according to claim 1, wherein: The two-axis voltage command calculation unit calculates the voltage command value of the first axis by adding at least the time differential value of the cross-linkage flux standard response value of the first axis and the value obtained by multiplying the cross-linkage flux standard response value of the second axis by the electrical angular velocity and -1. The voltage command value for the second axis is calculated by adding at least a time differential value of the interlinkage flux standard response value of the second axis and a value obtained by multiplying the interlinkage flux standard response value of the first axis by the electrical angular velocity.

3. The control device for an AC rotating electrical machine according to claim 2, wherein: The two-axis voltage command calculation unit calculates time differential values ​​of the first-axis and second-axis interlinkage flux command values ​​by combining time differential and response delay processing of the standard response.

4. The control device for an AC rotating electrical machine according to claim 2, wherein: The two-axis voltage command calculation unit calculates a time differential value of the first-axis interlinkage flux standard response value by subtracting the first-axis interlinkage flux standard response value from the first-axis interlinkage flux command value and dividing the value by a time constant of a response delay process of the standard response. The time differential value of the second-axis interlinkage flux standard response value is calculated by subtracting the second-axis interlinkage flux standard response value from the second-axis interlinkage flux command value and dividing it by the time constant of the response delay process of the standard response.

5. The control device for an AC rotating electrical machine according to claim 3, wherein: The two-axis voltage command calculation unit calculates a time differential value of the first-axis interlinkage flux standard response value by subtracting the first-axis interlinkage flux standard response value from the first-axis interlinkage flux command value and dividing the value by a time constant of a response delay process of the standard response. The time differential value of the second-axis interlinkage flux standard response value is calculated by subtracting the second-axis interlinkage flux standard response value from the second-axis interlinkage flux command value and dividing it by the time constant of the response delay process of the standard response.

6. The control device for an AC rotating electrical machine according to any one of claims 1 to 5, wherein: The two-axis voltage command calculation unit calculates the voltage command value of the first axis by adding the time differential value of the cross-linkage flux standard response value of the first axis, the value obtained by multiplying the cross-linkage flux standard response value of the second axis by the electrical angular velocity and -1, and the current value of the first axis corresponding to the cross-linkage flux standard response values ​​of the first and second axes, that is, the standard response corresponding current value of the first axis, by the winding resistance value. The voltage command value of the second axis is calculated by adding together the time differential value of the cross-linkage flux standard response value of the second axis, the value obtained by multiplying the cross-linkage flux standard response value of the first axis by the electrical angular velocity, and the value obtained by multiplying the current value of the second axis corresponding to the cross-linkage flux standard response value of the first and second axes, that is, the standard response corresponding current value of the second axis, by the winding resistance value. The two-axis voltage command calculation unit uses the current interlinkage flux characteristic data of the first axis with the current values ​​of the first axis and the second axis as input values ​​and the interlinkage flux of the first axis as output value, and the current interlinkage flux characteristic data of the second axis with the current values ​​of the first axis and the second axis as input values ​​and the interlinkage flux of the second axis as output value, and searches for the standard response corresponding current values ​​of the first axis and the second axis corresponding to the standard response values ​​of the interlinkage flux of the first axis and the second axis through repeated calculation.

7. The control device for an AC rotating electrical machine according to claim 6, wherein: The two-axis voltage command calculation unit performs the iterative calculation without using gradient information of interlinkage magnetic flux with respect to current value.

8. The control device for an AC rotating electrical machine according to claim 6, wherein: The two-axis voltage command calculation unit sets the initial values ​​of the standard response corresponding current values ​​of the first axis and the second axis searched this time to the standard response corresponding current values ​​of the first axis and the second axis searched last time.

9. The control device for an AC rotating electrical machine according to any one of claims 1 to 5, wherein: The two-axis voltage command calculation unit calculates the voltage command value of the first axis by adding the time differential value of the cross-linkage flux standard response value of the first axis, the value obtained by multiplying the cross-linkage flux standard response value of the second axis by the electrical angular velocity and -1, and the current value of the first axis corresponding to the cross-linkage flux standard response values ​​of the first and second axes, that is, the standard response corresponding current value of the first axis, by the winding resistance value. The voltage command value of the second axis is calculated by adding together the time differential value of the cross-linkage flux standard response value of the second axis, the value obtained by multiplying the cross-linkage flux standard response value of the first axis by the electrical angular velocity, and the value obtained by multiplying the current value of the second axis corresponding to the cross-linkage flux standard response value of the first and second axes, that is, the standard response corresponding current value of the second axis, by the winding resistance value. The two-axis voltage command calculation unit refers to the cross-linkage flux current characteristic data of the first axis, which takes the cross-linkage flux of the first axis and the second axis as input values ​​and the current value of the first axis as output values, and the cross-linkage flux current characteristic data of the second axis, which takes the cross-linkage flux of the first axis and the second axis as input values ​​and the current value of the second axis as output values, to calculate the standard response corresponding current values ​​of the first axis and the second axis corresponding to the standard response values ​​of the cross-linkage flux of the first axis and the second axis.

10. The control device for an AC rotating electrical machine according to any one of claims 1 to 5, wherein: The linkage flux standard response calculation unit utilizes filtering processing as response delay processing of the standard response.

11. A control device for an AC rotating electric machine, the control device for an AC rotating electric machine controlling an AC rotating electric machine having an n-phase armature winding via an inverter, where n is a natural number greater than or equal to 2, the control device comprising: a rotation detection unit that detects or estimates an electrical angle and an electrical angular velocity of a rotor of the AC rotating electric machine; a current command calculation unit that calculates current command values ​​for a first axis and a second axis in a two-axis coordinate system, i.e., a two-axis rotating coordinate system, the first axis and the second axis rotating in synchronization with the rotation of the rotor in terms of an electrical angle; a current standard response calculation unit configured to perform standard response delay processing on the current command values ​​of the first axis and the second axis to calculate current standard response values ​​of the first axis and the second axis; a two-axis voltage command calculation unit that calculates the standard response corresponding interlinkage fluxes of the first and second axes based on the standard response values ​​of the currents of the first and second axes, and calculates voltage command values ​​for the first and second axes on the rotating coordinate system of the two axes so as to feedforward change the currents of the first and second axes to the standard response values ​​of the currents of the first and second axes and the standard response corresponding interlinkage fluxes of the first and second axes, and the electrical angular velocity; an AC voltage command calculation unit that calculates an n-phase AC voltage command value to be applied to the n-phase armature winding based on the voltage command values ​​of the first and second axes and the electrical angle; and a switch control unit that controls on and off a plurality of switching elements included in the inverter based on the n-phase AC voltage command value; The two-axis voltage command calculation unit calculates the voltage command value of the first axis by adding at least a value obtained by multiplying the first-axis current differential first-axis inductance after partial differentiation of the first-axis linkage flux by the current of the first axis by the time differential value of the current standard response value of the first axis, a value obtained by multiplying the second-axis current differential first-axis inductance after partial differentiation of the first-axis linkage flux by the current of the second axis by the time differential value of the current standard response value of the second axis, and a value obtained by multiplying the linkage flux corresponding to the standard response of the second axis by the electrical angular velocity and -1, to calculate the voltage command value of the first axis. The voltage command value of the second axis is calculated by adding at least the value obtained by multiplying the second-axis inductance of the first-axis current differential after partial differentiation of the second-axis current with the cross-linked magnetic flux by the first-axis current by the time differential value of the current standard response value of the first axis, the value obtained by multiplying the second-axis inductance of the second-axis current differential after partial differentiation of the second-axis current with the second-axis current by the time differential value of the current standard response value of the second axis, and the value obtained by multiplying the cross-linked magnetic flux corresponding to the standard response of the first axis by the electrical angular velocity.

12. The control device for an AC rotating electrical machine according to claim 11, wherein: The two-axis voltage command calculation unit calculates the first-axis current differential first-axis inductance, the second-axis current differential first-axis inductance characteristic data having the current values ​​of the first and second axes as input values ​​and the first-axis current differential first-axis inductance as output value, the second-axis current differential first-axis inductance characteristic data having the current values ​​of the first and second axes as input values ​​and the second-axis current differential first-axis inductance as output value, the first-axis current differential second-axis inductance characteristic data having the current values ​​of the first and second axes as input values ​​and the first-axis current differential second-axis inductance as output value, and the second-axis current differential second-axis inductance characteristic data having the current values ​​of the first and second axes as input values ​​and the second-axis current differential second-axis inductance as output value, to calculate the first-axis current differential first-axis inductance, the second-axis current differential first-axis inductance, the first-axis current differential second-axis inductance, and the second-axis current differential second-axis inductance characteristic data corresponding to the current standard response values ​​of the first and second axes.

13. The control device for an AC rotating electrical machine according to claim 11 or 12, wherein: The two-axis voltage command calculation unit performs a calculation combining time differential and response delay processing of the standard response on the current command values ​​of the first and second axes to calculate time differential values ​​of the current standard response values ​​of the first and second axes.

14. The control device for an AC rotating electrical machine according to claim 11 or 12, wherein: The two-axis voltage command calculation unit calculates a time differential value of the first-axis current standard response value by subtracting the first-axis current standard response value from the first-axis current command value and dividing the value by a time constant of a response delay process of the standard response. A time differential value of the second-axis current standard response value is calculated by subtracting the second-axis current standard response value from the second-axis current command value and dividing it by a time constant of a response delay process of the standard response.

15. The control device for an AC rotating electrical machine according to claim 11 or 12, wherein: The two-axis voltage command calculation unit refers to the current interlinkage flux characteristic data of the first axis with the current values ​​of the first axis and the second axis as input values ​​and the interlinkage flux of the first axis as output value, and the current interlinkage flux characteristic data of the second axis with the current values ​​of the first axis and the second axis as input values ​​and the interlinkage flux of the second axis as output value, to calculate the interlinkage flux of the first axis and the second axis corresponding to the current standard response value of the first axis and the second axis, that is, the standard response corresponding interlinkage flux of the first axis and the second axis.

16. The control device for an AC rotating electrical machine according to claim 11 or 12, wherein: The current standard response calculation unit utilizes filtering processing as response delay processing of the standard response.

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