JP7112466B2 - Air conditioner motor control device and air conditioner motor control method - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act [1] Publication date November 8, 2019 4th STI-Gigaku 2019 (4th International Conference on ``Science of Technology Innovation'' 2019) STI-9-34 abstract <Documents> Abstract collection Summary of published research [2] Conference presentation (poster) Date November 8-9, 2019 (Presentation date: November 8, 2019) Meeting name 4th STI - Gigaku 2019 (4th International Conference on ``Science of Technology Innovation'' 2019) Venue Nagaoka University of Technology <Reference> Overview of the international conference and excerpt from the program <Reference> Research presentation poster [3] Publication date 2020 Proceedings of IEEJ/IAS(D) Online Technical Meetings 2020 (DOTeM 2020) <Materials> Proceedings Published research papers [4] Conference presentations (slides) Date: 2020 September 1-2 (announcement date: September 2, 2020) Name of meeting IEEJ/IAS(D) Online Technical Meetings 2020 (DOTeM 2020) Venue Web <Reference> Research presentation slides

TECHNICAL FIELD Embodiments of the present invention relate to a motor control device for an air conditioner and a motor control method for an air conditioner.

With the recent increase in IT services, the data center that supports the modern information society is an important facility, and high reliability is required for the air conditioning equipment that manages the environment. Pressure changes that occur when a compressor motor, which is the core of an air conditioner (air conditioner), rotates increase speed vibration as capacity increases, lowering reliability and increasing noise.
There are various types of compressors, but in rotary compressors, for example, rotary compressors that are widely used, the load torque pulsates periodically according to the mechanical angle phase, causing speed oscillation.
Peak filters and repetitive controls have been reported as methods for suppressing periodic speed vibrations of motors. can compensate for only the frequency component of , and when the frequency included in the disturbance extends over a wide range, the suppression performance deteriorates and sufficient vibration suppression cannot be achieved.

Further, conventionally, there has been known a speed control device for a compressor motor that suppresses vibration caused by speed fluctuation during rotation. In one of these speed control devices, a current correction amount for one cycle of load fluctuation is recorded and used as an integral term for current feedback control based on speed deviation.
In this motor speed control device, since the speed deviation is used for current feedback control, vibration may not be sufficiently suppressed.

JP-A-61-173690

The problem to be solved by the present invention is to provide a motor control device for an air conditioner and a motor control method for an air conditioner that can appropriately suppress vibration of a compressor motor.

An air conditioner motor control device according to an embodiment is a motor control device for an air conditioner that controls an inverter that drives a compressor motor, and includes a speed deviation calculation unit, a feedforward unit, a voltage command value calculation unit, It has an inverter control part. The speed deviation calculator calculates a speed deviation, which is a deviation between the speed command value and the speed of the compressor motor. The feedforward unit calculates a speed deviation signal, which is a speed deviation due to the influence of period disturbance of the compressor, based on the speed deviation calculated by the speed deviation calculation unit, and based on this speed deviation signal, outputs a feedforward gain. to output The voltage command value calculator calculates a command value of the voltage applied to the inverter based on the speed deviation calculated by the speed deviation calculator and the feedforward gain output set by the feedforward unit. The inverter control section controls the inverter by applying the voltage of the command value calculated by the voltage command value calculation section to the inverter. The transfer function of the feedforward part is set so that the transfer function of the part that receives the speed deviation signal and outputs the speed is 1, and the speed command value and the feedforward gain output are input and the speed is output. is set to the inverse of the closed-loop transfer function of the part where

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of the structure of the rotary compressor to which the motor control apparatus of an air conditioner and the motor control method of an air conditioner of embodiment are applicable. 4 is a graph showing torque fluctuations during operation of the rotary compressor; 1 is a block diagram showing an example of a controlled object of a motor control device for an air conditioner to which an embodiment can be applied; FIG. 4 is a waveform diagram showing an example of operation timings of the inverter shown in FIG. 3; FIG. 3 is a control block diagram of the motor control device for the air conditioner of the embodiment; FIG. It is a figure which shows an example etc. of a detailed structure of the feedforward part of the motor control apparatus of the air conditioner of embodiment. 1 is a diagram showing an example of a system to which a motor control device for an air conditioner according to an embodiment is applied; FIG. 8 is a diagram showing simulation results for the system shown in FIG. 7; FIG. FIG. 9 is a diagram showing confirmation results of responses after load torque fluctuations, assuming that the periodic disturbance applied in the example shown in FIG. 8 has increased; 4 is a flowchart for explaining an example of processing executed by the motor control device for the air conditioner of the embodiment;

Before describing the air conditioner motor control device and the air conditioner motor control method of the embodiment, an air conditioner to which the air conditioner motor control device and the air conditioner motor control method of the embodiment can be applied. A rotary compressor, which is an example of a compressor, will be described.

FIG. 1 is a diagram showing an example of the structure of a compression mechanism section of a rotary compressor to which the motor control device and motor control method of the embodiment can be applied. FIG. 2 is a graph showing torque fluctuations during operation of the rotary compressor.
The rotary compressor 1a comprises a cylindrical roller 3 eccentric with respect to a cylindrical cylinder 2. As shown in FIG. The roller 3 is eccentrically rotated by an eccentric portion 4 provided on a rotary shaft 5 which is aligned with the center of the cylinder 2 .
A compressor motor (not shown) rotates the rotary shaft 5 , so that the roller 3 rotates while being in contact with the inner surface of the cylinder 2 . A notch is provided in one part of the cylinder 2, and the vane 6 is inserted into the notch part without any gap. The back surface of the vane 6 is always pressed in the direction of the rotating shaft 5 by an elastic member such as a spring (not shown), and the tip of the vane 6 is in contact with the roller 3 .
Therefore, the space inside the cylinder 2 is partitioned into two spaces 10a and 10b by the roller 3, the cylinder 2 and the vane 6 as shown in FIG. Of the two spaces, the left space in FIG. 1 is a low-pressure suction space 10a, and the right space in FIG. 1 is a compression space 10b. A suction port 8 for sucking the refrigerant to be compressed is provided on the side of the cylinder 2 located in the suction space 10a, and a discharge port 9 for discharging the compressed refrigerant is provided on the side of the cylinder 2 located in the other compression space 10b. there is
When the compressor motor rotates the rotating shaft 5, the roller 3 rotates (drives) in the direction of the arrow in the drawing, and the volume of the compression space 10b is reduced, so that the gas refrigerant inside is compressed, and the cylinder 2 The high-pressure refrigerant inside is discharged from the discharge port 9 . At the same time as this compression, the volume of the suction space 10 a increases, so that the low-pressure gas refrigerant is sucked into the cylinder 2 from the suction port 8 .
Although not shown, the discharge port 9 is provided with an on-off valve, such as a reed valve, which is opened when the differential pressure between the inside and the outside exceeds a predetermined value. Thereby, the high pressure of the refrigerant discharged from the discharge port 9 is maintained.
In this way, since the rotary compressor repeats suction, compression, and discharge operations during one rotation of the rotary shaft, as shown in FIG. It pulsates periodically according to the mechanical angle phase, causing speed fluctuations. 1 and 2, a one-cylinder type rotary compressor has been described, but in a two-cylinder type, the cycle of the speed fluctuation occurs twice during one rotation of the rotary shaft. Furthermore, even in compressors having other mechanisms such as scroll type, the magnitude of load torque fluctuations is smaller than that of rotary compressors, but load torque fluctuations are similarly generated in accordance with the rotation of the rotary shaft.

Hereinafter, an air conditioner motor control device and an air conditioner motor control method according to embodiments will be described with reference to the drawings.

First, FIG. 3 is a block diagram for explaining an example of a motor control device 1 for a general air conditioner to which the embodiment can be applied.
The system shown in FIG. 3 includes an air conditioner compressor motor A1 (for example, IPMSM: embedded permanent magnet synchronous motor) and an inverter A2 that drives the compressor motor A1. The control target is the speed current control system of the _IPMSM to which the periodic disturbance TL corresponding to the mechanical angle phase is input as the load torque.
In FIG. 3, Cc(z) is the PI controller of the current control system discretized by the backward difference, and is represented by the following equation (1). Cv(z) is a PI controller of the speed control system discretized by the backward difference, and is represented by the equation (1). In equation (1), K _pc indicates the proportional parameter of the current control system, K _ic indicates the integral parameter of the current control system, Ts indicates the settling time, that is, the sampling period, and K _pv indicates the proportional parameter of the speed control system, and K _iv indicates the integral parameter of the speed control system.

In FIG. 3, Pc(z) is an IPMSM electrical model discretized by zero-order hold, and is represented by the following equation (2). Pv(z) is a mechanical model of the IPMSM discretized by zero-order hold and is expressed by equation (2).
In equation (2), L is the reluctance value of the motor, R is the resistance value of the motor, D is the coefficient of friction, and J is the moment of inertia of the motor.

FIG. 4 is a diagram showing an example of operation timing of the inverter A2 shown in FIG.
In the example shown in FIG. 4, when the control is interrupted at the peak of the carrier, for example, after sampling the current value of the compressor motor A1 detected by the current sensor at this timing, the voltage command value calculator calculates the voltage command value of the inverter A2. is calculated, and the inverter control section determines the switching state of the inverter A2.
If the voltage command value is updated immediately after the calculation, the number of switching times will increase and an error in the output voltage will occur, so updating the voltage command value of the inverter A2 will be delayed by one sampling as shown in FIG. Therefore, as shown in FIGS. 3 and 5, the transfer function of the inverter A2 is represented by "1/z" indicating one sampling delay.

As shown in FIG. 5, the air conditioner motor control device 1 of the embodiment is a feedforward control system that utilizes the mechanical angle periodic disturbance of the compressor.
If the periodic disturbance T _L is not applied, the speed response of the PI control system (actual speed of the compressor motor A1) ^{ω res} shown in _FIG . ω ^ref −ω ^res ) becomes zero. However, as described above, in the compressor, the periodic disturbance _TL is added at a period corresponding to the rotation period.
In such a state in which the periodic disturbance T _L is applied, the speed response ω ^res fluctuates according to the periodic disturbance T _L and a speed deviation influenced by the periodic disturbance T _L occurs. Here, let ω _res1 be the speed response in a state where the feedforward control system as ^shown in FIG ^. . That is, ω ^res =ω ^res1 +ω ^res2 .
The speed deviation reflecting the influence of this periodic disturbance _TL is the speed deviation signal e _feed (k) input to the feedforward gain setting section 12B. The details of the method for calculating the speed deviation signal e _feed (k) will be described later. FIG. 5(C) shows the speed response ω ^res2 when only the speed deviation signal e _feed (k) is input. Here, by matching the speed response ω ^res2 with the speed deviation signal e _feed (k), the vibration component of the speed response ω ^res1 based on the periodic disturbance T _L input to the feedforward control system shown in FIG. 5 is canceled. , the speed vibration of the compressor motor A1 can be reduced.
In FIG. 5, the transfer function of the feedforward gain setting section 12B is represented by "G _ff (z)". Here, FIG. 5A and FIG. 5B show the same control system by simply changing the order of the control blocks. FIG. 5(C) shows the speed response ω ^res2 when only the speed deviation signal e _feed (k) is input.
_IPMSM torque T is expressed by the following equation (3) and includes reluctance torque _. Assuming no influence, the torque T is expressed by the following equation (4). Based on this, the feedforward gain setting unit 12B sets the feedforward gain output r _f (k). Here, in equations (3) and (4), i _q is the q-axis current, _id is the d-axis current, L _d is the d-axis inductance, L _q is the q-axis inductance, and K _t is the torque constant (K _t 1 =p*Φ), where Φ is the interlinking magnetic flux of the permanent magnets of the motor, and p is the number of pole pairs.

In order to match the speed response ω ^res2 with the speed deviation signal e _feed (k), the entire feedforward control system shown in FIGS. 5B and 5C (that is, the speed deviation signal e _feed The _{transfer function} ^G _ff (z) needs to be set.
Therefore, in the air conditioner motor control device 1 of the embodiment shown in FIG. 5, the transfer function G _ff (z) of the feedforward gain setting unit 12B is the rectangular portion surrounded by the dashed line in FIG. The ^reciprocal of the closed-loop transfer function G _c ( ^z ) ( ₌ 1/G _c (z)).
A closed-loop transfer function G _c (z) including the speed control system, current control system, and inverter is expressed by the following equation (5).

Substituting equations (1) and (2) into equation (5) and arranging it gives equation (6), and G _c (z) is a function with a quintic denominator and a quadratic numerator. Here, D ₀ to D ₅ and N ₀ to N ₂ are coefficients.
On the other hand, the calculation of the transfer function G _ff (z) of the feedforward gain setting section 12B, which is the inverse of the closed loop transfer function G _c (z), is expressed by the following equation (7).

The transfer function G _ff (z) of the feedforward gain setting unit 12B has a fifth-order numerator and a second-order denominator, and cannot be realized in the form of equation (7).
Calculating the numerator/denominator for the equation (7) to make it feasible, the transfer function G _ff (z) of the feedforward gain setting unit 12B is expressed by the following equation (8). In equation (8), the first, second and third terms are the quotient of division, A _ff (z) is the remainder, B _ff (z) is the denominator, and A' _f3 to A' _f1 are coefficients. be.

As a result, the feedforward gain output r _f (k) shown in FIG. 5 is represented by the following equation (9).

In the expression (8), "z raised to the nth power" represents "n sampling advance". Therefore, the feedforward gain output r _f (k) represented by equation (9) includes not only the current value (e _feed (k)) of the velocity deviation signal but also the value (e _feed (k+3) ) is included. Here, 3 sampling means future values for 3 control cycles at the same timing in the cycle of the torque fluctuation _TL . Therefore, in order to perform feedforward control in the air conditioner motor control device 1 of the embodiment, it is necessary to acquire the future value of the speed deviation signal.

The motor control device 1 for an air conditioner of the embodiment utilizes the fact that the load torque generated by a compressor (for example, a rotary compressor) is periodic according to the mechanical angle. By assuming that _ω (=ω ^ref -ω ^res ) are equal, the speed deviation signal e _feed (k) is treated as the future value of all cycles in the calculation of equation (9).

FIG. 6A shows an example of the detailed configuration of the feedforward section 12 of the motor control device 1 for performing operations based on this assumption.
In the example shown in FIG. 6A, the feedforward section 12 includes a storage section 12A and a transfer function G _of (z) in addition to a feedforward gain setting section 12B. The storage unit 12A stores the speed deviation signal e feed (k) (see FIG. 5) to be input to the feedforward gain setting unit 12B, and stores the speed deviation signal e _feed (k) (see FIG. 5) affected by the period disturbance T _L (see FIG. 5) of the compressor. Store the deviation signal e _feed (k).
The feedforward gain setting unit 12B sets the speed deviation signal e _feed (k) for one cycle reflecting the influence of the period disturbance _TL of the compressor stored in the storage unit 12A to the next same cycle timing, that is, the same machine The feedforward gain output r _f (k) is obtained by using it as the future value of the velocity deviation signal e _feed (k) in angular (i.e. as the velocity deviation signal e _feed (k) for the next cycle of the compressor). set.
The number of stages N of the storage unit 12A that stores the speed deviation signal e _feed (k) is obtained by the following equation (10). In equation (10), _fs is the sampling frequency, _fr is the rotation frequency of the motor, and the number of stages N in the storage unit 12A is the number of samplings performed during one cycle of the compressor.

N=f _s /f _r (10)
In the case of a 2-cylinder rotary compressor, two periods of period disturbance _TL are generated per one rotation of the compressor drive motor, so sampling for half a rotation of the motor may be stored. In this case, the number of samples N to be stored is halved, and the memory capacity of the storage section 12A can be reduced.

When the feedforward control of the air conditioner motor control device 1 of the embodiment cancels the periodic disturbance _TL , the speed deviation signal e _feed (k) input to the storage unit 12A becomes 0, and the periodic disturbance is stored in the storage unit 12A. The component of _TL is not included (that is, the speed deviation signal e _feed (k) affected by the periodic disturbance _TL is not stored in the storage unit 12A). Therefore, in the air conditioner motor control device 1 of the embodiment, it is necessary to store the speed deviation signal e _feed (k) affected by the periodic disturbance _TL in the storage unit 12A.
Therefore, as shown in FIG. 6(A), the velocity deviation signal e _feed (k) affected by the periodic disturbance T _L has the same phase as the velocity deviation eω(k) at that time and is stored in the storage unit 12A. The previously stored speed deviation signal e _feed (k) is fed back via the transfer function G _of (z) from the feedforward control system to the speed response, and the added value is used as a new speed deviation signal e _feed (k) is stored in the storage unit 12A.
The relationship between the transfer function G _of (z) from the feedforward control system to the speed response, the closed loop transfer function G _c (z), and the transfer function G _ff (z) of the feedforward section 12 is given by the following equation (11): expressed.

_{Gof(z)=Gc(z)Gff ( z} )=1 (11)

As described above, in order to suppress the speed vibration due to the periodical disturbance T _L of the compressor, it is necessary to store the speed deviation signal e _feed (k) containing data for one cycle of the periodical disturbance of the compressor in the storage unit 12A. Therefore, the feedforward control of the motor control device 1 for the air conditioner of the embodiment is performed at the time when the time corresponding to one cycle of the compressor has elapsed from the time when the storage of the speed deviation signal e _feed (k) in the storage unit 12A is started. is started at For example, when the compressor motor A1 rotates once during one cycle of the compressor, the feedforward control of the motor control device 1 for an air conditioner according to the embodiment is to transfer the speed deviation signal e _feed (k) to the storage unit 12A. It is started when a period of time corresponding to one cycle of the period disturbance of the compressor motor A1, which is normally one revolution of the motor, has elapsed from the start of storage. As a result, the speed oscillation caused by the periodic disturbance _TL of the compressor can be suppressed and converged in a short period of time.

FIG. 6B shows an example of the motor control device 1 for an air conditioner according to the embodiment. (see FIGS. 4 and 6).
A motor control device 1 for an air conditioner includes a speed deviation calculator 11 , a feedforward gain setting unit 12B, a voltage command value calculator 13 , and an inverter controller 14 .
A speed deviation calculator 11 calculates a speed deviation e _ω (=ω ^ref −ω ^res ), which is the deviation between the speed command value ω ^ref and the actual speed ω ^res of the compressor motor A1. Here, the speed command value ω ^ref is input from a higher-level controller of the motor controller 1, such as a controller of an air conditioner. On the other hand, the actual speed ω ^res is output from speed detector 20 . As the speed detector 20, a method of reading the rotation speed from a rotary encoder attached to the compressor motor A1, a method of estimating the rotation speed from the motor current, or the like is used. Any acquisition method can be used as long as the speed can be detected accurately to some extent.
Note that the compressor used in the refrigeration cycle of the air conditioner is a closed container, and the inside of the compressor housing the compressor motor A1 is at high pressure and high temperature. be.
A feedforward gain setting unit 12B in the feedforward unit 12 is a speed deviation _eω influenced by the period disturbance T _L of the compressor calculated based on the speed deviation _eω calculated by the speed deviation calculation unit 11. A feedforward gain output r _f (k) is set based on the speed deviation signal e _feed (k).
Based on the speed deviation _eω calculated by the speed deviation calculator 11 and the feedforward gain output r _f (k) set by the feedforward gain setting unit 12B, the voltage command value calculator 13 supplies a Calculate the command value of the applied voltage.
Inverter control unit 14 controls inverter A<b>2 by instructing inverter A<b>2 to apply the voltage of the command value calculated by voltage command value calculation unit 13 . The inverter A2 drives the compressor motor A1 by outputting the voltage instructed by the voltage command value calculator 13 .

In the example shown in FIG. 6(B), as described above, the transfer function G _ff (z) of the feedforward gain setting unit 12B of the feedforward unit 12 is input with the speed deviation signal e _feed (k) and the actual speed The transfer function (the product of G _ff (z) and G _c (z)) of the portion that outputs ω ^res (that is, the entire feedforward control system shown in FIG. 5B) is set to 1, The closed-loop transfer function of the portion where the speed command value ω ^ref and the feedforward gain output r _f (k) are input and the actual speed ω ^res is output (that is, the rectangular portion surrounded by the dashed line in FIG. 5B) It is set to the reciprocal of G _c (z) (=1/G _c (z)).

FIG. 7 shows an example of a system A to which the air conditioner motor control device 1 of the embodiment is applied. Here, the parameters of the system A are set as shown in Table 1 below.

Furthermore, in this example, a PWM inverter with an ideal IGBT is used as the inverter A2, and an IPMSM is used as the compressor motor A1. The d-axis current command value is set to "0".

FIG. 8 is a diagram showing simulation results for the system A shown in FIG.
Specifically, FIG. 8A shows a time waveform (indicated by “Prop”) of the actual speed ω ^res of the compressor motor A1 to which the motor control device 1 for an air conditioner of the embodiment is applied, and a control example as a comparative example. It is shown in comparison with the time waveform of the actual speed of the compressor motor (indicated by “Conv”) to which no V is applied. The feedforward control of the air conditioner motor control device 1 of the embodiment is started at time 0.1 [s].
FIG. 8B shows the time waveform of the d-axis current of the compressor motor A1 to which the air conditioner motor control device 1 of the embodiment is applied (indicated by “Prop”) and the time waveform of the d-axis current of the comparative example ( shown as "Conv").
FIG. 8C shows the time waveform of the q-axis current of the compressor motor A1 to which the air conditioner motor control device 1 of the embodiment is applied (indicated by “Prop”) and the time waveform of the q-axis current of the comparative example ( shown as "Conv").
FIG. 8D shows a time waveform (indicated by “Prop”) of periodic disturbance T _L (load torque) corresponding to the mechanical angle phase of the compressor to which the air conditioner motor control device 1 of the embodiment is applied, and a comparison It is shown in comparison with the time waveform (indicated by “Conv”) of the periodic disturbance T _L (load torque) of the example.
FIG. 8E shows the time waveform of the mechanical angle phase of the compressor to which the air conditioner motor control device 1 of the embodiment is applied (indicated by “Prop”) and the time waveform of the mechanical angle phase of the comparative example (“Conv ) are shown in comparison. Here, compressor motor A1 is running at 20 rps.

In the comparative example indicated by "Conv" in FIGS. 8A to 8E, the feedforward control is not performed and the influence of the periodic disturbance _TL remains.
On the other hand, in the application example of the air conditioner motor control device 1 of the embodiment indicated by "Prop" in FIGS. 8A to 8E, feedforward control is started as shown in FIG. 8A. Vibration of the compressor motor A1 can be appropriately suppressed in the time period after the time of 0.1 [s].
Specifically, in the application example of the air conditioner motor control device 1 of the embodiment indicated by "Prop" in FIGS. has started to store the speed deviation signal e _feed (k) of .

In the measurement data shown in FIG. 8(A), the pp maximum value of the speed vibration of the comparative example indicated by "Conv" in the period of 0.15 [s] to 0.3 [s] that can be confirmed as a steady state and the pp maximum value of the speed vibration in the application example of the air conditioner motor control device 1 of the embodiment indicated by "Prop", the speed vibration suppression effect can be evaluated. As shown in FIG. 8A, in the application example of the air conditioner motor control device 1 of the embodiment indicated by "Prop", it is possible to confirm a vibration reduction of about 87.4% at the pp maximum value. did it.

FIG. 9 is a diagram showing the confirmation result of the response after the load torque fluctuates, assuming that the periodic disturbance _TL applied in the example shown in FIG. 8 has increased.
Specifically, FIG. 9A shows the time waveform (indicated by “Prop”) of the actual speed ω ^res of the compressor motor A1 to which the air conditioner motor control device 1 of the embodiment is applied, and the compressor motor of the comparative example. is shown in comparison with the time waveform of the actual speed of 1 (indicated by “Conv”).
FIG. 9B shows the time waveform of the periodic disturbance T _L (load torque) according to the mechanical angle phase of the compressor.
In the example shown in FIG. 9, the load torque increases 1.5 times at time 0.25 [s].

As described above, in the air conditioner motor control device 1 of the embodiment, the storage unit 12A stores the speed deviation signal e _feed (k) input to the feedforward unit 12 and the period disturbance T _L of the compressor. Store the affected velocity deviation signal e _feed (k). As in the example shown in FIG. 9B, when the load torque (periodic disturbance T _{L )} fluctuates, the storage unit 12A stores the velocity deviation signal e _feed (k ).
Furthermore, as described above, in the motor control device 1 for an air conditioner of the embodiment, the feedforward gain setting unit 12B in the feedforward unit 12 sets the influence of the period disturbance _TL of the compressor stored in the storage unit 12A. Speed deviation signal e _feed (k) for one cycle of the previous compressor received (for example, if the compressor motor A1 rotates once in one cycle of the period disturbance _TL of the compressor, the compressor motor A1 rotates once) as the future value of the velocity deviation signal e _feed (k) to set the feedforward gain output r _f (k).
That is, in the feedforward control of the air conditioner motor control device 1 of the embodiment indicated by "Prop" in FIG. Feedforward control reflecting the increase in the load torque is performed from the point of time 0.25 [s]. As a result, after 0.35 [s] after one revolution of the compressor motor A1, the speed fluctuation is substantially suppressed.
In this way, until the effect of suppressing speed vibration is sufficiently obtained, the compressor motor A1 rotates for two cycles after the load torque fluctuates (for example, when the compressor motor A1 rotates once in one compressor cycle). It was confirmed that a time of 2 rotations) was required.

FIG. 10 is a flowchart for explaining an example of a process executed by the motor control device 1 for an air conditioner according to the embodiment.
In the example shown in FIG. 10, in step S1, the speed deviation calculator 11 calculates the speed deviation e _ω (=ω ^ref −ω ^res ), which is the deviation between the speed command value ω ^ref and the actual speed ω ^res of the compressor motor A1. calculate.
Next, in step S2, the feedforward gain setting unit 12B outputs a speed deviation signal e _feed which is the speed deviation e _ω calculated in step S1 and the speed deviation e _ω affected by the period disturbance _TL of the compressor. Based on (k), set the feedforward gain output r _f (k).
Next, in step S3, the voltage command value calculation unit 13, based on the speed deviation e _ω calculated in step S1 and the feedforward gain output r _f (k) set by the feedforward gain setting unit 12B, A command value for the voltage applied to the inverter A2 is calculated.
Next, in step S4, the inverter control unit 14 controls the inverter A2 by applying the voltage of the command value calculated in step S3 to the inverter A2.
Specifically, the transfer function G _ff (z) of the feedforward gain setting unit 12B of the feedforward unit 12 has a transfer function of 1 at the portion where the speed deviation signal e _feed (k) is input and the actual speed ω ^res is output. and set to the reciprocal of the closed-loop transfer function G _c (z) of the portion where the speed command value ω ^ref and the feedforward gain output r _f (k) are input and the actual speed ω ^res is output be done.

According to at least one embodiment described above, the motor control device 1 for an air conditioner is a motor control device 1 that controls an inverter A2 that drives a compressor motor A1, and includes a speed deviation calculation unit 11 and a feedforward unit. 12, a voltage command value calculation unit 13, and an inverter control unit 14. A speed deviation calculator 11 calculates a speed deviation e _ω that is a deviation between a speed command value ω ^ref and an actual speed ω ^res of the compressor motor A1. setting a feedforward gain output r _f (k) based on the speed deviation signal e _feed (k), which is the deviation e _ω and the speed deviation e _ω affected by the periodic disturbance T _L of the compressor A1; The voltage command value calculation unit 13 applies a voltage to the inverter A2 based on the speed deviation _eω calculated by the speed deviation calculation unit 11 and the feedforward gain output _rf (k) set by the feedforward unit 12. The inverter control unit 14 applies the command value voltage calculated by the voltage command value calculation unit 13 to the inverter A2 to control the inverter A2. The transfer function G _ff (z) of the forward gain setting unit 12B is set so that the transfer function of the portion where the speed deviation signal e _feed (k) is input and the actual speed ω ^res is output is 1, and the speed The command value ω ^ref and the feedforward gain output r _f (k) are input and set to the reciprocal of the closed-loop transfer function G _c (z) for outputting the actual speed ω ^res . Thereby, the vibration of the compressor motor can be appropriately suppressed.

At least part of the functions of the air conditioner motor control device 1 in the above-described embodiment (including modifications) may be realized by a computer. In that case, a program for realizing this function may be recorded in a computer-readable recording medium, and the program recorded in this recording medium may be read into a computer system and executed. It should be noted that the "computer system" referred to here includes hardware such as an OS and peripheral devices. In addition, “computer-readable recording media” refers to portable media such as flexible discs, magneto-optical discs, ROMs, CD-ROMs, DVD-ROMs, USB memories, and storage devices such as hard disks built into computer systems. Say things. Furthermore, "computer-readable recording medium" means a medium that dynamically retains a program for a short period of time, like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. It may also include a device that holds a program for a certain period of time, such as a volatile memory inside a computer system that serves as a server or client in that case. Further, the program may be for realizing part of the functions described above, or may be capable of realizing the functions described above in combination with a program already recorded in the computer system.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1... Motor control apparatus 11... Speed deviation calculation part 12... Feed forward part 12A... Storage part 12B... Feed forward gain setting part 13... Voltage command value calculation part 14... Inverter control part 20... Speed detection device, A... system, A1... compressor motor, A2... inverter

Claims (4)

A motor control device for an air conditioner that controls an inverter that drives a compressor motor,
a speed deviation calculator that calculates a speed deviation that is a deviation between a speed command value and a speed of the compressor motor;
Based on the speed deviation calculated by the speed deviation calculating section, a speed deviation signal is calculated as a speed deviation based on the influence of period disturbance of the compressor, and based on this speed deviation signal, a feedforward gain output is output. a feedforward section;
A voltage command value calculation unit that calculates a command value of the voltage applied to the inverter based on the speed deviation calculated by the speed deviation calculation unit and the feedforward gain output set by the feedforward unit. When,
an inverter control unit that controls the inverter by applying to the inverter the voltage of the command value calculated by the voltage command value calculation unit;
The transfer function of the feedforward section is
The transfer function of the part that receives the speed deviation signal and outputs the speed is set to be 1, and
The transfer function of the feedforward unit is set to the reciprocal of the closed loop transfer function of the portion that outputs the speed when the speed command value and the feedforward gain output are input ,
The feedforward unit includes a storage unit that stores the speed deviation signal affected by the period disturbance of the compressor,
The feedforward unit uses the speed deviation signal for one cycle reflecting the influence of the cycle disturbance of the compressor stored in the storage unit as a future value of the speed deviation signal at the timing of the next same cycle. Set the feedforward gain output by
For the speed deviation at the time when the compressor is affected by the period disturbance, the speed deviation signal previously stored in the storage section having the same phase is fed back via a transfer function from the feedforward control system to the speed response. and the storage unit stores the value fed back and added as a new speed deviation signal,
A transfer function from the feedforward control system to the speed response is 1,
Air conditioner motor controller. 2. A motor controller for an air conditioner according to claim 1, wherein said speed of said compressor motor is estimated from a current flowing through said compressor motor. The feedforward section is
setting the feedforward gain output by using the speed deviation signal for one cycle of the period disturbance of the compressor stored in the storage unit as a future value of the speed deviation signal;
The motor control device for an air conditioner according to claim 1. A motor control method for an air conditioner that controls an inverter that drives a compressor motor,
a speed deviation calculation step of calculating a speed deviation, which is a deviation between the speed command value and the speed of the compressor motor;
A feedforward gain setting step of outputting a feedforward gain output based on a speed deviation signal, which is the speed deviation affected by the period disturbance of the compressor calculated based on the speed deviation calculated in the speed deviation calculating step. When,
a voltage command value calculating step of calculating a command value of the voltage applied to the inverter based on the speed deviation calculated in the speed deviation calculating step and the feedforward gain output;
an inverter control step of controlling the inverter by applying the voltage of the command value calculated in the voltage command value calculation step to the inverter,
The transfer function in the feedforward gain setting step for setting the feedforward gain output is
The transfer function of the part that receives the speed deviation signal and outputs the speed is set to be 1, and
The transfer function in the feedforward gain setting step is set to the reciprocal of the closed loop transfer function of the part that outputs the speed when the speed command value and the feedforward gain output are input,
The feedforward unit that executes the feedforward gain setting step includes a storage unit that stores the speed deviation signal affected by the period disturbance of the compressor,
The feedforward unit uses the speed deviation signal for one cycle reflecting the influence of the cycle disturbance of the compressor stored in the storage unit as a future value of the speed deviation signal at the timing of the next same cycle. Set the feedforward gain output by
For the speed deviation at the time when the compressor is affected by the period disturbance, the speed deviation signal previously stored in the storage section having the same phase is fed back via a transfer function from the feedforward control system to the speed response. and the storage unit stores the value fed back and added as a new speed deviation signal,
A transfer function from the feedforward control system to the speed response is 1,
A motor control method for an air conditioner.

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