JP2010051162A - Controlling apparatus and method of pm motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controlling apparatus and a method of a PM motor which can suppress a periodic disturbance of torque ripple accurately. <P>SOLUTION: The controlling apparatus has a torque ripple estimating means and a periodic signal generator. The torque ripple estimating means estimates a torque ripple value from a motor angular velocity ω, a nonlinear friction compensating torque T<SB>f</SB>(ω), and a motor torque instructing value T<SB>ref</SB>, etc. The periodic signal compensating generator generates a compensating signal repeatedly from the torque ripple value estimated using the torque estimating means and by bringing a first switch into ON only during one period of disturbance, and stores periodic disturbance data in a memory, and further, performs compensation by outputting the periodic disturbance data in turn as a disturbance compensating signal for giving a prediction value which proceeds by one sample, by bringing a second switch into ON. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a PM motor control device and control method. More specifically, the present invention relates to control for suppressing torque ripple of a PM motor using a current control method based on perfect tracking control (PTC).

  Permanent magnet synchronous motors (PMSM) are widely used in industry. However, when driving a PM motor, the occurrence of torque ripple in the PM motor becomes a problem. As a factor for generating this torque ripple, there may be a spatial harmonic that may exist due to the structure of the field magnetic pole. In addition, the inverter dead time, the current sensor offset, and the measurement error also cause harmonics, and the harmonics cause torque ripple. Due to the occurrence of this torque ripple, loss increases and efficiency is deteriorated, and vibration noise is generated. Therefore, it is considered indispensable to suppress this torque ripple from the viewpoint of the efficiency and controllability of the PM motor.

  Various research and development have been conducted on various problems related to torque ripple in various motors, and many examples have already been proposed, such as measurement methods, analysis, and compensation by current control.

  In an embedded permanent magnet synchronous motor (IPMSM), a method for suppressing torque ripple in a rotating coordinate system synchronized with a harmonic has been proposed (see Non-Patent Document 1). In addition, a technique for reducing torque ripple in an IPMSM in which an induced voltage is distorted by using a plant model including harmonics has been proposed (see Non-Patent Document 2). Furthermore, a method by feedforward compensation in which torque ripple is modeled by encoder position information has been proposed (see Non-Patent Document 3).

K. Yoshimoto, Y. Kitajima: “A Novel Harmonic Current Control for IPMSMs”, International Power Electronics Conference Niigata, pp. 2042-2048, 2005 Y. Kawano, A. Kawamura: “Analysis on Current Regulation for Torque Control for a Very Distorted CEMF Type IPSMS”, Power Conversion Conference Nagoya, pp. 694-698, 2007 D. Kawase, M. Iwasaki, M. Kawafuku, H. Hirai: “Modeling and Compensation for Cogging Torque in Ball Screw-Driven Table System”, IIC-08-131, pp. 88-94, 2008 (in Japanese) T. Nakai, H. Fujimoto: “Proposal of harmonic current suppression method of PM motor based on repetitive perfect tracking control”, SPC-07-37, pp. 37-42, 2007 (in Japanese) Atsuo Kawamura: “Contemporary Power Electronics”, Mathematical Engineering, 2005 K. Sakata, H. Fujimoto: “Perfect Tracking Control of Servo Motor Based on Precise Model Considering Current Loop and PWM Hold”, T. IEEJapan, Vol. 127-D, No. 6, pp. 587-593, 2007 (in Japanese) H. Fujimoto, Y. Hori, A. Kawamura: “Perfect Tracking Control Method Based on MultirateFeedforward Control”, T. SICE, Vol. 36, No. 9, pp. 766-772, 2000 (in Japanese)

  However, in the PM motor torque ripple suppression control as described above, there is a problem that a response delay of about several ms occurs at each sample point.

  The present invention has been made in view of such problems, and the object of the present invention is to accurately suppress torque ripple, which is a periodic disturbance, by performing current control based on perfect tracking control (PTC). An object of the present invention is to provide a PM motor control apparatus and control method that can perform the above-described process.

In order to achieve such an object, one aspect of the present invention is a control device that suppresses torque ripple of a PM motor using a current control method based on perfect tracking control (PTC), and includes a motor angular velocity ω and nonlinear friction. Compensation torque T _f (ω) and motor torque command value T _ref can be measured

And based on torque ripple value

A torque ripple estimation means for estimating the torque ripple, and the first switch is turned on only for one period of disturbance to generate a repetitive compensation signal from the torque ripple value estimated by the torque ripple estimation means, and the periodic disturbance data is stored in a memory, A periodic signal generator is provided that performs compensation by turning on the second switch and sequentially outputting the periodic disturbance data as a disturbance compensation signal that gives a prediction value one sample ahead.

  Here, in this control apparatus, the torque ripple value estimated by the torque ripple estimating means is expressed by the following equation:

The period disturbance data calculated from the above and stored in the memory can be T _d / T _s (T _d : disturbance period, T _s : control period of the digital signal processor).

  In the present control device, a Q filter for removing non-periodic disturbance can be further provided at the output of the periodic signal generator.

Another aspect of the present invention is a control method for suppressing torque ripple of a PM motor using a current control method based on perfect tracking control (PTC), which includes a motor angular velocity ω, a nonlinear friction compensation torque T _f (ω), and a motor. Torque command value T _ref and measurable

And based on torque ripple value

A torque ripple estimation step for estimating the torque ripple, and the first switch is turned on only for one period of disturbance to generate a repetitive compensation signal from the torque ripple value estimated by the torque ripple estimation step, and the period disturbance data is stored in a memory; A disturbance compensation signal output step by a periodic signal generator for performing compensation by sequentially turning on the second switch and outputting the periodic disturbance data as a disturbance compensation signal that gives a prediction value one sample ahead. It is characterized by.

  Here, in this control method, the torque ripple value estimated in the torque ripple estimation step is expressed by the following equation:

The period disturbance data calculated from the above and stored in the memory can be T _d / T _s (T _d : disturbance period, T _s : control period of the digital signal processor).

  The control method may further include a non-periodic disturbance removing step of removing the non-periodic disturbance by a Q filter attached to the output of the periodic signal generator.

  According to the present invention, by performing current control based on perfect tracking control (PTC), it is possible to accurately suppress torque ripple, which is a periodic disturbance, and to improve the delay in response at each sample point and achieve the target. Control to follow the value can be performed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, the motor model and discretization in the embodiment of the present invention will be described below.

<Dq model>
In the embodiment of the present invention, a dq model (that is, a dq coordinate system) is used as a motor model. As is well known to those skilled in the art, in the dq coordinate system, the d-axis current represents the excitation current and the q-axis current represents the torque current.

  Here, the voltage equation of PMSM in the dq coordinate system is expressed by the following equation (1).

Where v is a voltage, R is a resistance, L is an inductance, ω is an angular velocity, i is a current, and _Ke is an induced voltage constant. The subscripts d and q represent the d axis and the q axis, respectively.

When PMSM is a surface permanent magnet synchronous motor (SPMSM), L _d = L _q = L. Since the torque T and the angular velocity ω are determined only by the value of the current i _q regardless of the value of the current i _d , the relationship between the current i _q , the torque T, and the angular velocity ω is expressed by the following equation (2). become.

However, _Kt is a torque constant. Thus, a control block diagram of SPMSM expressed in dq coordinates is expressed as shown in FIG.

  In general, when control is performed using the dq model, the following equations (3) and (4) are applied to the equation (1) so as to cancel out the interference term (COUPLING TERM) for the sake of simplicity. DECOUPLING CONTROL).

Assuming that the field weakening control is not performed and the value of i _d is maintained at 0, the q-axis plant can be regarded as a DC motor model. At this time, the characteristic from the current command value to the output current is a first-order lag system as shown in FIG.

  Here, when the state variable x is the current i and the input u is the voltage v ′, the state equation of the continuous time system is expressed by the following equation (5).

However, A _C = −R / L, B _C = 1 / L, and C _C = 1.

<Discretization based on PWM hold>
FIG. 3 shows an example of a single-phase inverter. In this example, an arbitrary output voltage V [k] cannot be output, and only 0 or the DC applied voltage ± E [V] of the inverter is output. Consider this as PWM hold (see Non-Patent Document 5) and consider controlling the pulse width.

  Assuming that the state equation of the control target is the following equation (6), as shown in the following equation (7), a more precise discretization model is created with the switching time ΔT [k] as the control input u [k]. can do.

here,

And

And C _S = C _C. However, when ΔT [k] is negative, −E [V] is output.

  Here, when the control target is SPMSM, the control system is designed from the dq model, so the control input is the switching time in the dq coordinate system, but since a three-phase inverter is used as the inverter, A control input for outputting a PWM pulse is derived (see Non-Patent Document 6), and the control input is used.

<Extraction of torque ripple component>
In order to suppress the torque ripple, the torque ripple is measured using SPMSM.

  Non-Patent Document 3 describes that the motor torque command value in the constant speed driving test includes torque ripple and non-linear friction compensation torque. Further, it is described that the motor torque command value includes acceleration torque corresponding to speed pulsation. Therefore, the torque ripple is extracted by removing components other than the torque ripple from the motor torque command value of the constant speed driving test. Furthermore, after the load side is speed controlled to drive at a constant speed, the main motor is torque controlled to extract torque ripple.

  Assuming that the nonlinear friction torque is expressed as a function of the motor angular velocity ω, the equation of motion of the motor is as shown in the following equation (8).

However, T _ref is a motor torque command value, T _f (ω) is a nonlinear friction compensation torque defined by a function of angular velocity ω, and T _r (θ) is a torque ripple depending on the motor position.

  As described above, since the speed control is performed on the load side, in a steady state,

And T _r (θ) take a time average to be zero. Therefore, T _f (ω) can be obtained from the motor torque command value from the above equation (8).

FIG. 4 shows a graph plotting T _f (ω) against motor angular velocity ω. Here, ω is an angular velocity in the electric angle of the motor. The horizontal axis of this graph is the angular velocity ω [rad / s], and the vertical axis of this graph is the nonlinear friction compensation torque T _f (ω) [N · m × 10 ⁻³ ]. A regression curve determined from a plot of T _f (ω) versus motor angular velocity ω is shown in this graph. Thereby, the value of T _f (ω) with respect to the motor angular velocity ω becomes known. That is, the function T _f (ω) is known. Also,

Is a measurable term.

  Therefore, the torque ripple estimate is

When, known and since the function T _f (omega), the motor torque command value T _ref, and measurable

And using equation (8),

Can be obtained from the following equation (9).

  FIG. 5 shows a graph of an estimated waveform of the torque ripple extracted based on Expression (9). In this graph, the horizontal axis represents the motor position θ [rad], and the vertical axis represents the torque ripple [N · m]. Three legends of 5 [Hz], 10 [Hz], and 25 [Hz] represent the drive frequency in electrical angle. As shown in the figure, it can be confirmed that even if the motor speed changes, the torque ripple with respect to the motor position θ does not change, and it is possible to extract the torque ripple that depends only on the motor angle.

  FIG. 6 is a graph showing the frequency analysis result (torque ripple spectrum) of the torque ripple measurement value when the drive frequency is 10 Hz (electrical angle). In this graph, the horizontal axis represents the motor rotation frequency (Frequency) [Hz], and the vertical axis represents the torque ripple measurement value (Torque) [N · m]. As shown in the figure, it can be confirmed that the torque ripple is mainly an electrical angle second, sixth, twelfth and eighteenth component of the motor rotation frequency.

<Control system>
Perfect tracking control (PTC) method
FIG. 7 shows a current control block diagram according to the PTC method. As shown in the figure, the PTC method is a two-degree-of-freedom control system including a feedforward controller and a feedback controller. The feedforward controller is a stable inverse system of the plant, and for a nominal plant, it is guaranteed that the tracking error is completely zero on the sample point. When there is a disturbance or plant fluctuation, the feedback controller suppresses the tracking error.

  Non-Patent Document 7 describes that for an n-th order control target, complete tracking is guaranteed by multi-rate control that switches control input n times between one sample point. In the case shown in FIG. 7, since the control target is primary, PTC is realized by normal single rate control.

Next, the design of the feedforward controller will be described. Using the above PWM hold, the above equation (5) is discretized at the control input period _Tu . As a result, the following equation (10), which is a discrete-time plant with the control input u [k] as the time input ΔT [k], is obtained.

However,

And

And C = 1.

  Therefore, the stable inverse model of the plant is expressed by the following equation (11), and the nominal output is expressed by the following equation (12).

Also, C _PI [z] shown in FIG. 7 is a PI controller, which is designed as shown in the following equation (13) using pole-zero cancellation, and using Tustin transform at the control cycle T _s. It is made discrete. However, τ is 1 [ms].

Current control method based on PTC
FIG. 8 shows a block diagram of a single rate control system according to the current control method based on PTC in the PM motor control apparatus according to the embodiment of the present invention. The current control method based on PTC is a method in which repetitive control is applied to the above-described PTC method, and is for suppressing periodic disturbance (see Non-Patent Document 4). In the case of an arbitrary waveform command value, switching from PTC to current control based on PTC ensures a good target value tracking characteristic before switching.

  FIG. 9 is a timing chart showing switching of the switches in the PM motor control apparatus according to the embodiment of the present invention. As shown in the figure, in the current control method based on the PTC, after reaching a steady state, the switch 1 (SWITCH1) is turned on only for one period of disturbance (drive), and the switch 2 (SWITCH2) is turned off during this period. . Thus, a repetitive compensation signal is generated, and thereafter, the repetitive compensation is performed by outputting the compensation signals in order. Therefore, in this case, feedforward compensation is performed.

When the disturbance period T _d and the control period T _{s of the} digital signal processor (DSP) are used, the relationship between T _d , T _s, and the N _d stage memory is N _d = T _d / T _s . The N _d data (that is, periodic disturbance) stored in the memory is a disturbance compensation signal that gives a predictive value of one sample ahead using the periodic signal generator (PSG) shown in FIG. Is output. The PSG can give an appropriate command value as long as the disturbance does not change suddenly, and can suppress the periodic disturbance for each sample point.

[First Embodiment-Control Using First-Order Model]
<Control system design>
FIG. 10 shows a motor model including torque ripple using the above-described first-order model.

<Simulation 1>
A simulation was performed on the motor as shown in FIG. 10 using the method proposed in this specification. In this simulation, the drive frequency is 10 Hz in electrical angle, and torque ripples of the second, sixth, twelfth, and eighteenth components are 12 [mN · m], 22 [mN · m], 4 [mN · m, respectively. m] and 4 [mN · m]. Learning was started from 1.0 s after the simulation was started, and repetitive compensation was started from 1.1 s after the simulation was started. The compensation signal was repeatedly generated according to the above equation (9), and the torque was evaluated as being directly measurable.

  11 to 13 show graphs of the simulation results. FIG. 11A shows a change in torque over time (torque waveform) according to the simulation in this embodiment, and FIG. 11B shows the result of simulation in this embodiment.

The change with time is shown. 11A and 11B, the horizontal axis represents time (Time) [s], and the vertical axis represents torque (Torque) [N · m]. FIG. 12A shows a torque spectrum before repeated compensation by simulation in the present embodiment, and FIG. 12B shows a torque spectrum after repeated compensation by simulation in the present embodiment. 12A and 12B, the horizontal axis represents frequency (Hz), and the vertical axis represents torque (N · m). FIG. 13A shows the change over time of the operation amount by the simulation in this embodiment, and FIG. 13B shows the operation amount spectrum after repeated compensation by the simulation in this embodiment. In FIG. 13A, the horizontal axis represents time (Time) [s], and the vertical axis represents the manipulated variable (u _q ) [s × 10 ⁻⁶ ]. In FIG. 13B, the horizontal axis represents the frequency (Frequency) [Hz], and the vertical axis represents the manipulated variable (u) [s × 10 ⁻⁷ ].

  From the above simulation results, it can be confirmed that the effect of torque ripple is suppressed after compensation by repeatedly performing compensation.

<Experiment 1>
An experiment of torque ripple suppression was performed using the method proposed in this specification. In this experiment, the SPMSM shown in the block diagram of FIG. 1 was used, speed control was performed with the load-side motor so that the drive frequency was 10 Hz in electrical angle, and torque control was performed with the main motor. The values of various parameters of the PM motor used in this experiment are as shown in Table 1 below.

In this experiment, an average value filter for 10 cycles was used in order to repeatedly generate a compensation signal according to the above equation (9) and reduce non-periodic disturbance included in the signal. Furthermore, in this experiment, in order to remove noise and non-periodic disturbance caused by the sensor, a filter called a Q filter was attached to the output of the PSG (see FIG. 14). In the simulation described above, dead time compensation or the like is not taken into consideration, but in this experiment, dead time compensation was always performed both before and after repeated compensation. The output of the PSG and r [k], and the output of the Q filter and r _f [k], the relationship between r [k] and r _f [k] is represented by the following equation (14).

  This Q filter is a low-pass filter having no phase delay, and requires a value one sample ahead as can be seen from the above equation (14). Also, the smaller the value of the adjustment parameter γ, the more rolloff is obtained and the stability is increased, but the suppression of repeated disturbance is lost. In this experiment, γ = 2 and the cutoff frequency was 1.8 kHz. In this experiment, since the torque sensor is in a low band, the measured value of torque cannot be used. Therefore, evaluation was performed using the estimated value of torque and the acceleration torque for speed pulsation.

  15 to 17 show graphs of the results of this experiment. FIG. 15A shows the change over time of the estimated torque ripple value according to the experiment in this embodiment, and FIG. 15B shows the result according to the experiment in this embodiment.

The change with time is shown. 15A and 15B, the horizontal axis represents time (Time) [s], and the vertical axis represents torque (Torque) [N · m]. FIG. 16A shows a torque spectrum before repeated compensation by an experiment in this embodiment, and FIG. 16B shows a torque spectrum after repeated compensation by an experiment in this embodiment. 16A and 16B, the horizontal axis represents frequency (Hz), and the vertical axis represents torque (N · m). FIG. 17A shows the change over time of the manipulated variable according to the experiment in this embodiment, and FIG. 17B shows the manipulated variable spectrum after repeated compensation according to the experiment in this embodiment. In FIG. 17A, the horizontal axis represents time (Time) [s], and the vertical axis represents the manipulated variable (u _q ) [s × 10 ⁻⁵ ]. In FIG. 17B, the horizontal axis represents the frequency (Frequency) [Hz], and the vertical axis represents the manipulated variable (u) [s × 10 ⁻⁸ ].

  From the above experimental results, it can be confirmed that the torque ripple component can be suppressed by using iterative compensation as in the simulation results.

[Second embodiment-control using second-order model]
Next, control using a secondary model will be described.

<Control system design>
The relationship between the q-axis current i _q and the q-axis input voltage v _q and the relationship between the q-axis current i _q and the angular velocity ω in PMSM when non-interference control is not performed are respectively expressed by the following equations (15) and (16 ).

Assuming that the d-axis current is controlled to 0, the state equation of the controlled object with _iq and ω as state variables is expressed by the following equation (17).

However,

And

And

It is. Multi-rate feedforward control is performed using the above equation of state.

Next, the derivation of the multi-rate feedforward controller will be described. The A, B, C, and D matrices of the control object discretized with the period T _r are obtained by the following expression (18), which is a controllable canonical system state equation of the control object discretized with the period _Tu. Then, the following equation (19) can be derived.

Here, since the B matrix of the above equation (19) is regular, the state variable x _d [i + 1] of one sample ahead is changed by multi-rate as in the following equations (20) and (21). It is possible to realize a stable inverse system of a controlled object as an input variable.

Thereby, it is possible to guarantee complete follow-up for each cycle T _{r with} respect to the nominal plant.

<Simulation 2>
A simulation was performed using the above control law in the present embodiment. FIG. 18 is a control block diagram of the PM motor according to the present embodiment. As the target value of the angular velocity ω, a stepped command value is obtained through a low-pass filter. The steady value was set to an electrical angle of 10 Hz, and the time constant of the low-pass filter was set to 0.5 seconds. Further, the current command value obtained through the speed feedback controller C ₂ (s) is used as the current target value. Other simulation conditions are the same as the simulation conditions in the first embodiment.

19 to 22 show graphs of the simulation results. FIG. 19A shows the change with time (torque waveform) of the torque according to the simulation in the present embodiment. FIG. 19B shows the change with time of current (current waveform) by the simulation in the present embodiment. FIG. 19C shows a change with time in the operation amount (operation amount waveform) by the simulation in the present embodiment. 19A, the horizontal axis represents time (Time) [s], the vertical axis represents torque (Torque) [N · m], and in FIG. 19B, the horizontal axis represents time (Time) [Time] [s]. s], the vertical axis represents current (i) [A], and in FIG. 19C, the horizontal axis represents time (Time) [s], and the vertical axis represents torque (Torque) [N · m]. Represents. FIG. 20A shows a torque spectrum before repeated compensation by simulation in the present embodiment, and FIG. 20B shows a torque spectrum after repeated compensation by simulation in the present embodiment. 20A and 20B, the horizontal axis represents frequency (Hz), and the vertical axis represents torque (N · m). FIG. 21A shows a current spectrum before repeated compensation by the simulation in the present embodiment, and FIG. 21B shows a current spectrum after repeated compensation by the simulation in the present embodiment. 21A and 21B, the horizontal axis represents frequency (Frequency) [Hz], and the vertical axis represents current (i) [A]. FIG. 22 shows an operation amount spectrum after repeated compensation by the simulation in the present embodiment. In FIG. 22, the horizontal axis represents frequency (Frequency) [Hz], and the vertical axis represents manipulated variable (u) [s × 10 ⁻⁷ ].

  It can be confirmed from the simulation results shown in FIGS. 20A and 20B that the second-order, sixth-order, twelfth-order, and eighteenth-order components can be suppressed.

  As described above, according to the present invention, by performing current control based on perfect tracking control (PTC), it is possible to accurately suppress the torque ripple that is a periodic disturbance, and the response of each sample point. Control to improve the delay and follow the target value can be performed.

It is a control block diagram of SPMSM expressed in dq coordinates. It is a control block diagram which shows the characteristic from an electric current command value to an output current at the time of considering a plant of q axis as a DC motor model. It is explanatory drawing which shows an example of a single phase inverter. It is a figure which shows the graph which plotted _Tf ((omega)) with respect to motor angular velocity (omega). It is a figure which shows the graph of the estimated waveform of the torque ripple extracted based on the formula proposed by this specification. It is a graph which shows the frequency analysis result (torque ripple spectrum) of a torque ripple measured value in case a drive frequency is 10 Hz (electrical angle). It is a current control block diagram according to the PTC method. It is a block diagram of the single rate control system according to the current control method based on perfect tracking control (PTC) in the control apparatus of PM motor which concerns on embodiment of this invention. It is a timing diagram which shows switching of the switch in the control apparatus of PM motor which concerns on embodiment of this invention. It is a figure which shows the motor model containing a torque ripple using a primary model. It is a figure which shows the graph of the simulation result in the motor model shown in FIG. 10, (a) is a time-dependent change (torque waveform) of torque, (b) is

It is a graph which shows a time-dependent change.
FIG. 11 is a graph showing a simulation result in the motor model shown in FIG. 10, where (a) is a torque spectrum before repeated compensation, and (b) is a graph showing a torque spectrum after repeated compensation. FIGS. 11A and 11B are graphs showing simulation results in the motor model shown in FIG. 10. FIG. 11A is a graph showing an operation amount change with time, and FIG. It is a control block diagram of a periodic signal generator to which a Q filter for removing noise and non-periodic disturbance by a sensor is attached. It is a figure which shows the graph of the experimental result in the motor model shown in FIG. 10, (a) is a time-dependent change of a torque ripple estimated value, (b) is a figure.

It is a graph which shows a time-dependent change.
It is a figure which shows the graph of the experimental result in the motor model shown in FIG. 10, (a) is a torque spectrum before repeated compensation, (b) is a graph which shows the torque spectrum after repeated compensation. FIGS. 11A and 11B are graphs showing experimental results in the motor model shown in FIG. 10. FIG. 11A is a graph showing an operation amount change with time, and FIG. It is a control block diagram of PM motor concerning one embodiment of the present invention. It is a figure which shows the simulation result in embodiment shown in FIG. 18, (a) is a time-dependent change (torque waveform) of a torque, (b) is a time-dependent change (current waveform) of an electric current, (c) is operation. It is a graph which shows the time-dependent change (operation amount waveform) of quantity. It is a figure which shows the simulation result in embodiment shown in FIG. 18, (a) is a torque spectrum before repeated compensation, (b) is a graph which shows the torque spectrum after repeated compensation. It is a figure which shows the simulation result in embodiment shown in FIG. 18, (a) is a current spectrum before repetitive compensation, (b) is a graph which shows the current spectrum after repetitive compensation. It is a figure which shows the simulation result in embodiment shown in FIG. 18, and is a graph which shows the manipulated variable spectrum after repetitive compensation.

Claims (6)

A control device for suppressing torque ripple of a PM motor using a current control method based on perfect tracking control (PTC),
Motor angular velocity ω, nonlinear friction compensation torque T _f (ω), and motor torque command value T _ref can be measured.

And based on torque ripple value

Torque ripple estimating means for estimating
The first switch is turned on only for one period of disturbance, a compensation signal is repeatedly generated from the torque ripple value estimated by the torque ripple estimating means, the period disturbance data is stored in the memory, and the second switch is turned on. And a periodic signal generator that performs compensation by sequentially outputting the periodic disturbance data as a disturbance compensation signal that gives a prediction value one sample ahead. The torque ripple value estimated by the torque ripple estimation means is expressed by the following equation:

Calculated from
2. The control device according to claim 1, wherein the period disturbance data stored in the memory is T _d / T _s (T _d : disturbance period, T _s : control period of a digital signal processor). . The control device according to claim 1, further comprising a Q filter for removing non-periodic disturbances at an output of the periodic signal generator. A control method for suppressing torque ripple of a PM motor using a current control method based on perfect tracking control (PTC),
The motor angular velocity ω, the nonlinear friction compensation torque T _f (ω), and the motor torque command value T _ref can be measured.

And based on torque ripple value

A torque ripple estimating step for estimating
The first switch is turned on only for one period of disturbance, a compensation signal is repeatedly generated from the torque ripple value estimated by the torque ripple estimation step, the period disturbance data is stored in the memory, and the second switch is turned on. A disturbance compensation signal output step by a periodic signal generator for performing compensation by sequentially outputting the periodic disturbance data as a disturbance compensation signal giving a prediction value one sample ahead. . The torque ripple value estimated in the torque ripple estimation step is expressed by the following equation:

Calculated from
5. The control method according to claim 4, wherein the period disturbance data stored in the memory is T _d / T _s (T _d : disturbance period, T _s : control period of a digital signal processor). . The control method according to claim 4, further comprising: a non-periodic disturbance removing step of removing a non-periodic disturbance by a Q filter attached to an output of the periodic signal generator.

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