ENGINE CONTROL DEVICE

Abstract

A motor control device is provided that is capable of both reducing the time required to design and adjust the amount of correction for each amplitude and phase according to response characteristics, and ensuring a torque ripple suppression effect. A motor control device 1 drives a motor 5 using an inverter 4. The motor control device 1 includes a harmonic control command value computer 8, which provides the first harmonic control command values ​​i*. dqh and φ* dqh from a torque command value τ* and an electrical angle θ e of the motor 5, a response compensator 9, the second harmonic control command values ​​i** dqh and φ** dqh calculated by performing response characteristic compensation on the first harmonic control command value i* dqhaccording to the speed of the motor 5, and a voltage command calculator 3 which provides a voltage command value v* dq based on a control command to output a torque of the torque command value τ* and the second harmonic control command values ​​i** dqh and φ** dqh calculated.

Description

Technical field

[0001] The present invention relates to a motor control device that suppresses a torque ripple generated by a motor during motor control. State of the art

[0002] Motors have achieved high power densities to be used in applications with limited cargo space, such as automobiles. Consequently, these motors are increasingly used in environments where magnetic saturation occurs. A magnetic saturation range causes an increase in torque ripple, which can induce vibration and noise, and therefore necessitates, in particular, torque ripple suppression control.

[0003] Examples of a conventional device that reduces vibration by suppressing a motor's torque ripple include a technique described in PTL 1. PTL 1 describes a device that generates a table relating to the amplitude and phase of a torque ripple according to a torque produced by a motor, calculates a torque ripple compensation value, corrected to suppress the amplitude and phase of the torque ripple, with reference to the table, and superimposes the torque ripple compensation value onto a command value. This correction enables the suppression of torque ripple with a frequency exceeding a control band of the torque. Citation list of patent literature

[0004] PTL 1: JP 5784787 B2 Summary of the invention: Technical problem

[0005] If an amplitude and a phase are corrected according to the rotational speed with the amount of torque ripple compensation to be superimposed, the response characteristics of the torque must be known.

[0006] Unfortunately, due to a change in the motor constant caused by magnetic saturation at high torque, the design response value of an FB controller and the actual torque response value typically differ, and therefore the suppression accuracy of the torque ripple deteriorates.

[0007] Therefore, setting or measuring response characteristics for each of the operating conditions, such as torque and current, is required to ensure accuracy, which takes time to design a control system.

[0008] It is an object of the present invention to provide a motor control device that is capable of both reducing the time required to design and adjust the amount of correction of each amplitude and phase according to response characteristics, and ensuring a torque ripple suppression effect.

[0009] The present invention uses a control system with a robust response to a change in a motor constant for an FB control to individually correct a phase and an amplitude according to a rotational speed for a harmonic command value of a dq axis. Solution to the problem

[0010] To achieve the above objective, the present invention is configured as follows.

[0011] A motor control device drives a motor with an inverter and includes a harmonic control command value calculator, which acquires a first harmonic control command value from a torque command value and an electrical angle of the motor; a response compensator, which calculates a second harmonic control command value, which is acquired by performing a response characteristic compensation on the first harmonic control command value according to the speed of the motor; and a voltage command calculator, which calculates a voltage command value based on a control command to output a torque of the torque command value and the second harmonic control command value. Advantageous effects of the invention

[0012] The present invention enables the provision of a motor control device capable of both reducing the time required to design and adjust the amount of correction of each amplitude and phase according to response characteristics, and ensuring a torque ripple suppression effect. Brief description of the drawings [ Fig. 1] Fig. Figure 1 is a schematic block diagram of an engine control device according to a first embodiment of the present invention. [ Fig. 2] Fig. Figure 2 is a diagram illustrating a difference between an actual current and a sensing current, where the difference is caused by a current sensing delay. [ Fig. 3] Fig. Figure 3 is a schematic block diagram of an engine control device according to a second embodiment of the present invention. [ Fig. 4A] Fig. 4A is a diagram illustrating the conversion of an electric current into a magnetic flux. [ Fig. 4B] Fig. 4B is a diagram illustrating the conversion of an electric current into a magnetic flux. Description of embodiments

[0013] Embodiments of the present invention are described below with reference to the accompanying drawings. Embodiments (First Embodiment)

[0014] Fig. Figure 1 is a functional block diagram illustrating a configuration of an engine control device 1 according to a first embodiment of the present invention.

[0015] The term "dq-axis" as described below represents the "d-axis and q-axis". With respect to the subscript parameters X (such as "i" and "v") described below, "xdq" represents a "vector quantity (Xd, Xq)" and "Xuvw" represents a "vector quantity (Xu, Xv, Xw)" unless otherwise specified. Here, "uvw" represents three phases of an alternating current, that is, the "U-phase, V-phase, and W-phase".

[0016] Fig. Figure 1 illustrates the motor control device 1, which controls the speed and torque of the motor 5 by controlling the switching of an inverter 4, which supplies alternating current to the motor 5.

[0017] The motor control device 1 according to the first embodiment contains an arithmetic processing device, such as a microcomputer, and functions as a unit by executing a predetermined program.

[0018] The inverter 4 according to the first embodiment is a three-phase inverter with a three-phase full bridge circuit as a main circuit, wherein the three-phase full bridge circuit includes a semiconductor switching element, such as an IGBT or a MOSFET.

[0019] The motor 5 according to the first embodiment is a three-phase AC synchronous motor, which is a rotating machine to which, for example, a permanent magnet synchronous motor is applied.

[0020] Motor 5 is not limited to a synchronous machine, and an induction machine can be applied to Motor 5. Motor 5 is not limited to a rotary machine, and a linear motor can be applied to Motor 5. Motor 5 can have a power generation function.

[0021] As in Fig. As illustrated in Figure 1, the motor control device 1 contains a control command computer 13 which receives a torque command value 10 (τ*) and a dq-axis current command value 2 (i*). dq ) outputs, a voltage command computer 3, an electrical angle detector 6, an electrical angular velocity computer 7, a harmonic control command value computer 8, a response compensator 9, a voltage command superposition unit 10, a voltage command value dq / three-phase axis converter 11 and a measuring current three-phase / dq axis converter 12.

[0022] The torque command value 10 is given by a higher-level controller or operating system.

[0023] The dq axis current command value 2 is calculated as a dq axis current necessary to output a torque from the motor 5 in response to a given torque command. Although the torque output per current is typically determined as maximum power per hour (MTPA), the present invention is effective for any current.

[0024] The voltage command computer 3 generates a voltage command value v* dq according to a difference between a dq-axis current measurement value i dq and a dq-axis current command value i*dq, such that the dq-axis current sensing value i dq equal to the dq axis current command value i* dq is.

[0025] The voltage command computer 3 according to the first embodiment calculates the voltage command value v* dq using the dq axis current command value i* dq (of a d-axis current command value i* q and a q-axis current command value i* q) with a configuration in which integrators are connected in series with each dq axis for a motor reversal model of expression (1) below. Then, a variable with t at one end of a subtraction of L representing an inductance denotes a dynamic inductance, and a variable without t denotes a static inductance. The static inductance is a value determined by a ratio between a dq axis current and a dq axis magnetic flux, and the dynamic inductance refers to a rate of change of a magnetic flux close to a reference current. Although the dynamic inductance and the static inductance coincide under a non-magnetic saturation condition, the dynamic inductance and the static inductance do not coincide when magnetic saturation is present. [VdVq]=(R+sLdt−ωeLdqsLdqt+ωeLqsLqdt+ωeLdR+sLqt−ωeLqd)(id*iq*)+ωe(0Ke)

[0026] In expression (1), Vd represents a d-axis voltage of motor 5, Vq represents a q-axis voltage of motor 5, R represents a resistance value of a winding of motor 5, Ld represents a d-axis inductance of motor 5, Lq represents a q-axis inductance of motor 5, Ldq and Lqd each represent a disturbance inductance between the d-axis and the q-axis of motor 5, Ke represents an induced voltage constant, Ldt represents a dynamic inductance of the d-axis of motor 5, Lqt represents a dynamic inductance of the q-axis of motor 5, Ldqt and Lqdt each represent a dynamic disturbance inductance between the d-axis and the q-axis of motor 5, i* d represents a d-axis current command value, i* q represents a q-axis current command value and ω e represents an electrical angular velocity of motor 5.

[0027] The voltage command computer 3 is not limited to the configuration of the first embodiment and can use a control configuration obtained by equivalence deformation or an approximation model that ignores a term with a minor influence. For example, if use in a magnetic saturation region is not assumed, the dynamic inductance and the static inductance can be treated as the same value, or an integrator and a motor reversal model can be combined to be configured as a PI controller and a non-disturbance controller.

[0028] The electric angle detector 6 calculates and outputs an electric angle θ. e based on a rotational position signal from a rotational sensor (not illustrated) provided in the motor 5. The rotational sensor outputs a rotational position signal according to a mechanical angle (θ). m) of a rotor of the motor 5, and the electric angle detector 6 calculates the electric angle θ e using a number of pole pairs (p) of motor 5 and a relationship (θ e = p · θ m ) between the electric angle θe, the mechanical angle θ m and the number of pole pairs (p).

[0029] A mechanical angle resolver, a Hall sensor, a rotary encoder, or similar device can be used as the rotation sensor. Alternatively, an electrical angle can be estimated from a current or voltage using a general position-sensorless control method.

[0030] Similar to the electric angle calculator 6, the electric angular velocity calculator 7 calculates and gives an electric angular velocity ω. ebased on a rotational position signal from a rotation sensor (not illustrated) provided in the motor 5. The electric angle calculator 7 calculates the electric angular velocity ω. e using the number of pole pairs (p) of motor 5, the relationship (θ e = p · θ m ) between the electric angle θ e and the mechanical angle θ m and p and a relation (ω e = dθ e / dt) between the electric angle θ e and the electric angular velocity ω e The electric angular velocity calculator 7 can include a differentiator that calculates the electric angular velocity ω. e by differentiating the electric angle θ e calculated, which is output by the electric angle calculator 6.

[0031] The harmonic control command value calculator 8 outputs a first harmonic control command value i*dqh from a torque command value τ*.

[0032] The response compensator 9 contains a response compensation table or a response compensation function and outputs a second harmonic control command value i**dqh, which is obtained by correcting the first harmonic control command value i*dqh by the magnitude of the correction of a phase and an amplitude, where the magnitude is derived from the electric angular velocity ω e calculated using the response compensation table or the response compensation function.

[0033] The voltage command value dq / three-phase axis converter 11 (in Fig. (1, specified as dq / uvw) converts the voltage command value v* dq , which is output by the voltage command computer 3, into a three-phase voltage according to the electrical angle θ eand generates a signal to control a switching of inverter 4. At this point, θ can ec , which is obtained by compensating for a delay until the voltage command value is actually reflected in the inverter 4, instead of the electrical angle θ e be used.

[0034] The measuring current three-phase / dq axis converter 12 converts a three-phase current, which is detected by a current sensor, into a dq axis current i dq according to θ e um. At this point, θe can be calculated taking into account a current detection delay instead of θ. e be used.

[0035] The operation of the present invention is described below, while the operation of the motor control device 1 is described.

[0036] First, the harmonic control command value calculator 8, which has received the torque command value τ*, calculates the first harmonic control command value i*. dqh as in expression (2) below. In expression (2), n represents an order of magnitude of a torque ripple. idqh*=(idh*iqh*)=(Idncos(nθe+θdn+θdelay)Iqncos(nθe+θqn+θdelay))

[0037] At this point, the dq-axis current I dq , θdq determined in advance by analysis, a test, or the like, to be captured by a table or the like using the torque command value τ* as an argument. Then θ delay The operating amount for advancing a phase by a delay time generated between a detected current and a current actually flowing through motor 5, and is given by nT delay ωe is calculated, where the delay time is given by T delayThis operation allows for the separation of a response of an FB controller and a dead time, and the design of a response compensation table, which is later described as a simple first-order delay function.

[0038] If the delay is not corrected, the actual current will deviate from the measured current, as in Fig. Figure 2 illustrates this, even if the sensing current and a current command value match. Thus, a current flows with a phase that differs from the originally desired phase, causing a degradation of performance. Although the sensing current and the current command value are perfectly matched, they are shown in Figure 2 for illustrative purposes. Fig. 2 shifted from each other.

[0039] Holding dq-axis current sensing values ​​I dq , θ dqUsing complex coefficients allows for the avoidance of phase discontinuities when referring to a table.

[0040] The response compensator 9 calculates an electrical angular frequency of the torque ripple with nω e for the first harmonic control command value i* dqh Then the amount of the correction of the amplitude I mod and the amount of the correction of a phase θ mod , the nω e This corresponds to a two-dimensional table of amplitude correction and an electrical angular frequency, and a two-dimensional table of phase correction and an electrical angular frequency. These two-dimensional tables can be implemented as a function of expression (3) below, since a response is designed as a first-order delay system in the first embodiment. In expression (3), ω represents acr represents a control response angle frequency. (Inmodθnmod)=(1+(nωeωacr)2atannωeωacr)

[0041] At this point, the second harmonic control command value i** dqh calculated according to expression (4) below. idqh**=(idh**iqh**)=(IdnImodcos(nθe+θdn+θnmod+θdelay)IqnImodcos(nθe+θqn+θnmod+θdelay))

[0042] The voltage command calculator 3 calculates the voltage command value v* dq from a final current command value, which is derived from the second harmonic control command value i** dqh and the dq-axis current command value i* dq is calculated, and a current measurement.

[0043] When d-axis and q-axis control response angle frequencies are designed to have different values, a correction table of amplitude and one phase must be maintained for each combination of dq-axis control response characteristics for torque response characteristics. This is time-consuming to design. In contrast, current compensation allows response characteristics to be determined for each axis, so that only one correction table or a function of amplitude and one phase is required for each different control response angle frequency ω. acr This requires preparation. Therefore, a torque ripple suppression effect can be ensured while reducing the design man-hour.

[0044] Although a torque ripple at a single frequency is targeted to illustrate operation in the first embodiment, torque ripples containing torque ripples at a multitude of frequencies can be addressed by performing identical operation for each suitable order and adding the results of all orders at an output stage of the response compensator 9. At this point, the response compensator 9 detects the magnitude of the amplitude correction I. mod and the amount of the correction of a phase θ mod for every order.

[0045] The first embodiment enables the provision of a motor control device capable of both reducing the time required to design and adjust the amount of correction of each amplitude and phase according to response characteristics, and ensuring a torque ripple suppression effect. (Second embodiment)

[0046] Next, a second embodiment will be described.

[0047] A difference from the first embodiment is shown by reference to a block diagram of the second embodiment, which is in Fig. 3 is illustrated and described.

[0048] The second embodiment includes a converter 100 which provides a dq-axis current command value 2 (i* dq ) calculated from a control command computer 13 based on a torque command value 10 (τ*) and the dq-axis current command value 2 (i* dq) into a magnetic flux command value φ dq converts, a converter 101, which converts a measured current i dq in a measured magnetic flux value φ dq converts to a harmonic control command value calculator 8, which provides a first harmonic control command value φ* dqh records, which is pre-captured from a harmonic current command value corresponding to the torque command value 10 (τ*) according to expression (5) below, and the first harmonic control command value φ* dqh from the torque command value 10 (τ*) at the time of control outputs a response compensator 9, which outputs a second harmonic control command value φ** dqh from the first harmonic control command value φ* dqh and an electric angular velocity ω e calculated, and a voltage command calculator 3, which calculates a voltage command value v* dq from the second harmonic control command value φ** dqh and a magnetic flux measurement φ dq(a d-axis magnetic flux measurement φ d , a q-axis magnetic flux measurement φ q ) calculated using an engine reversal model according to expression (6) below.

[0049] Each of the first harmonic control command value φ* dqh and the second harmonic control command value φ** dqh In the second embodiment, a physical quantity of magnetic flux differs from a current in the first embodiment. However, f represents d In the following expression (5) a relationship between a current and a magnetic flux that is detected in advance by analysis or a test, such as a function that depends on a dq-axis current, as in Fig. 4A and Fig.Figure 4B illustrates this. The converter 100 and the converter 101 in the present configuration can use the same function or can use a table with a resolution that differs between a command value and a measured value according to the required accuracy. ϕdqh*=fd(id*+idh*,iq*+iqh*)−fd(id*,iq*) [VdVq]=RLdLq−LdqLqd[Lq−Lqd−LdqLd][ϕd−Keϕq]+s[ϕdϕd]+ωe[0−110][ϕdϕq]

[0050] In expression (6), Vd represents a d-axis voltage of motor 5, Vq represents a q-axis voltage of motor 5, R represents a resistance value of a winding of motor 5, Ld represents a d-axis inductance of motor 5, Lq represents a q-axis inductance of motor 5, Ldq and Lqd each represent a disturbance inductance between the d-axis and the q-axis of motor 5, Ke represents an induced voltage constant, φd represents a magnetic flux measurement of the d-axis, φ qrepresents a magnetic flux measurement of the q-axis and ω e represents an electrical angular velocity of motor 5.

[0051] The operation of the second embodiment is described in comparison to the first embodiment. Using a magnetic flux instead of a current allows a reverse motor model to reduce variables such as those in expression (6) compared to expression (1) using the current. Consequently, not only can similar effects to those in the first embodiment be obtained, but the number of searches and constant tables can also be reduced, while taking into account nonlinearity due to magnetic saturation.

[0052] As in the first embodiment, the inverting model of the motor according to expression (6) is not limited to the configuration of the second embodiment and may use a control configuration obtained by equivalence deformation or an approximation model that ignores a term that has a minor influence. Reference symbol list 1 Engine control unit 2 dq-axis current command value 3 voltage command calculators 4 inverters 5 engine 6 electric angle detector 7 electric angular velocity calculator 8 Harmonic Control Command Value Calculator 9 Response compensator 10 Torque command value 11 Voltage command value dq / Three-phase axis converter 12 Measuring current three-phase / dq axis converters 13 control command computers 100, 101 converters i* dqh , φ* dqhfirst harmonic control command value i** dqh , φ** dqh second harmonic control command value ω e electric angular velocity QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 5784787 B2

[0004]

Claims

[1] Motor control device for driving a motor with an inverter, the motor control device comprising: a harmonic control command value computer that obtains a first harmonic control command value from a torque command value and an electrical angle of the motor; a response compensator that calculates a second harmonic control command value, which is obtained by performing response characteristic compensation on the first harmonic control command value according to the speed of the motor; and a voltage command calculator that calculates a voltage command value based on a control command to output a torque of the torque command value and the second harmonic control command value. [2] Motor control device according to claim 1, wherein the harmonic control command value calculator calculates the first harmonic control command value for each order. [3] Motor control device according to claim 1, wherein the response compensator corrects an amplitude and a phase of the first harmonic control command value for each order. [4] Motor control device according to claim 1, wherein the voltage command computer calculates the voltage command value according to expression (1) below, [VdVq]=(R+sLdt−ωeLdqsLdqt+ωeLqsLqdt+ωeLdR+sLqt−ωeLqd)(id*iq*)+ωe(0Ke) where Vd represents a d-axis voltage of the motor, Vq represents a q-axis voltage of the motor, R represents a resistance value of a winding of the motor, Ld represents a d-axis inductance of the motor, Lq represents a q-axis inductance of the motor, Ldq and Lqd each represent a disturbance inductance between the d-axis and the q-axis of the motor, Ke represents an induced voltage constant, Ldt represents a dynamic inductance of the d-axis of the motor, Lqt represents a dynamic inductance of the q-axis of the motor, Ldqt and Lqdt each represent a dynamic disturbance inductance between the d-axis and the q-axis of the motor, i*d represents a d-axis current command value, i*q represents a q-axis current command value, and ω e represents an electrical angular velocity of the motor. [5] Motor control device according to claim 1, wherein the voltage command computer calculates the voltage command value according to the following expression (6), [VdVq]=RLdLq−LdqLqd[Lq−Lqd−LdqLd][ϕd−Keϕq]+s[ϕdϕq]+ωe[0−110][ϕdϕq] where Vd represents a d-axis voltage of the motor, Vq represents a q-axis voltage of the motor, R represents a resistance value of a winding of the motor, Ld represents a d-axis inductance of the motor, Lq represents a q-axis inductance of the motor, Ldq and Lqd each represent a disturbance inductance between the d-axis and the q-axis of the motor, Ke represents an induced voltage constant, φd represents a magnetic flux measurement of the d-axis of the motor, φq represents a magnetic flux measurement of the q-axis of the motor, and ω e represents an electrical angular velocity of the motor.

Images