KR102621423B1 - Motor drive device and outdoor unit of air conditioner using it - Google Patents

Abstract

A motor drive device with high versatility that can support a variety of motors is provided, as it can reduce noise and vibration caused by machine resonance without requiring prior adjustment through preliminary testing, etc. It has a power conversion circuit that drives a permanent magnet synchronous motor, a control unit that controls the power conversion circuit, and a current sensor that detects a three-phase current flowing through the permanent magnet synchronous motor, wherein the control unit is connected to the current sensor. a 3-phase/dq conversion unit that converts the 3-phase detection current detected by A torque pulsation suppression control unit that calculates a voltage correction command that contributes to reducing the pulsation torque of the permanent magnet synchronous motor based on a setting value related to the distortion component of the induced voltage of the magnet synchronous motor, and the d-axis detection current and q-axis detection It is characterized by having a parameter estimation unit that corrects the set value so that at least one pulsation component of the current is reduced, and an addition unit that adds the command voltage and the voltage correction command.

Description

Motor drive device and outdoor unit of air conditioner using it

The present invention relates to a motor driving device that drives a motor (electric motor) and its control, and in particular to a technology effective for application to drive control of a motor (electric motor) used in applications requiring quietness.

The induced voltage of a permanent magnet synchronous motor ideally contains only fundamental wave components, but in reality, spatial harmonic components such as 5th order components and 7th order components exist. The distortion component of this induced voltage becomes a factor causing the motor torque to pulsate, and this fluctuating torque becomes an excitation source of machine resonance, thereby generating noise and vibration.

Noise and vibration caused by machine resonance can be reduced, for example, by providing anti-vibration rubber at the location where the motor is fixed or at the rotating shaft receiving portion. However, the problem with this method is that as the number of parts increases, the structure becomes more complex and the cost further increases.

As background technology in this technical field, there is technology such as Patent Document 1, for example. Patent Document 1 discloses “(as a countermeasure for not using anti-vibration rubber) a technique for suppressing torque pulsation, which is the source of mechanical resonance, by controlling a permanent magnet (synchronous) motor.”

In the motor drive device of Patent Document 1, a current correction command generated according to the distortion component of the induced voltage is superimposed on the command current for generating the desired motor torque. This current correction command is a command that changes with respect to the rotor position, and it is said that torque pulsation can be canceled by this.

Japanese Patent Publication No. 2011-151883

However, the torque pulsation suppression control is performed by obtaining information on the distortion component of the induced voltage in advance in a preliminary test, storing it in memory, etc., and generating a command to cancel the torque pulsation based on the stored data during driving. It can be realized. This method is effective, for example, in cases where high control stability must be secured in a motor drive device in which driving conditions constantly change.

However, in a motor drive device to which an unspecified motor is connected, there is a problem in that it is difficult to secure versatility because preliminary testing is required for each motor.

In Patent Document 1, information on the distortion component of the induced voltage is estimated using a command signal during driving, and torque pulsation suppression control is performed. This method does not require a preliminary test to acquire the distortion component of the induced voltage, so it can ensure high versatility even in a motor drive device to which an unspecified motor is connected.

However, if a command signal is used, there is a risk that the estimation accuracy may be deteriorated due to the influence of modeling errors, calculation errors, etc., and as a result, there is a possibility that a sufficient torque pulsation suppression effect cannot be obtained.

Therefore, the object of the present invention is to provide a highly versatile motor drive device capable of reducing noise and vibration caused by machine resonance without requiring prior adjustment through preliminary testing, etc., and capable of supporting a variety of motors, and an air conditioner using the same. The goal is to provide an outdoor unit.

In order to solve the above problem, the present invention includes a power conversion circuit that drives a permanent magnet synchronous motor, a control unit that controls the power conversion circuit, and a current sensor that detects a three-phase current flowing through the permanent magnet synchronous motor. The control unit includes a three-phase/dq conversion unit that converts the three-phase detection current detected by the current sensor into a d-axis detection current and a q-axis detection current, and a command contributing to driving the permanent magnet synchronous motor. A command voltage calculation unit that calculates a voltage, and a torque pulsation suppression control unit that calculates a voltage correction command that contributes to reducing the pulsation torque of the permanent magnet synchronous motor based on a set value for the distortion component of the induced voltage of the permanent magnet synchronous motor. and a parameter estimation unit that corrects the set value so that the pulsation component of at least one of the d-axis detection current and the q-axis detection current is reduced, and an addition unit that adds the command voltage and the voltage correction command. do.

Additionally, the present invention includes a permanent magnet synchronous motor, a motor driving device for driving the permanent magnet synchronous motor, a fan connected to the permanent magnet synchronous motor, a frame for installing the permanent magnet synchronous motor, and a compressor device system. This is an outdoor unit of an air conditioner, wherein the motor drive device is a motor drive device having the above features.

According to the present invention, it is possible to reduce noise and vibration caused by machine resonance without requiring prior adjustment through preliminary testing, etc., and realize a highly versatile motor drive device capable of supporting a variety of motors and an outdoor unit of an air conditioner using the same. You can.

Problems, configurations, and effects other than those described above will be revealed by the description of the embodiments below.

1 is a diagram showing the configuration of a motor drive device according to Embodiment 1 of the present invention.
FIG. 2 is a diagram showing the operation waveforms of the torque, induced voltage, and current of the motor (when the correction current (ΔIq) is not applied).
FIG. 3 is a diagram showing the operation waveforms of the torque, induced voltage, and current of the motor (when applying the correction current (ΔIq)).
FIG. 4 is a diagram showing the configuration of the parameter estimation unit of FIG. 1.
FIG. 5 is a diagram showing the configuration of the pulsation current detection unit of FIG. 4.
FIG. 6 is a diagram showing the configuration of the parameter correction unit of FIG. 4.
Figure 7 is a diagram showing the configuration of a parameter estimation unit according to Embodiment 2 of the present invention.
FIG. 8 is a diagram showing the configuration of the pulsation current detection unit of FIG. 7 and the concept of signal processing.
Figure 9 is a diagram showing the configuration of a parameter correction unit according to Embodiment 3 of the present invention.
Fig. 10 is a diagram showing the configuration of a motor drive device according to Embodiment 5 of the present invention.
Fig. 11 is a diagram showing the configuration of a motor drive device according to Embodiment 6 of the present invention.
FIG. 12 is a diagram showing the configuration of the parameter estimation unit of FIG. 11.
Fig. 13 is a diagram showing an outdoor unit of an air conditioner according to Example 7 of the present invention.

Hereinafter, embodiments of the present invention will be described using the drawings. In addition, in each drawing, the same components are assigned the same reference numerals, and detailed descriptions of overlapping parts are omitted.

[Example 1]

With reference to FIGS. 1 to 6, a motor driving device and a control method thereof according to Embodiment 1 of the present invention will be described.

1 is a configuration diagram of a motor drive device of this embodiment. As shown in FIG. 1, the motor drive device 100 of this embodiment includes a control unit 102 and a power conversion circuit 103 that drives a permanent magnet synchronous motor 101 (hereinafter also simply referred to as “motor”). ), a current sensor 104, and a command speed generator 105.

The control unit 102 controls the rotation speed of the motor 101 with vector control as its basic configuration.

The control unit 102 generates a three-phase command based on the command speed (ωr*) provided from the command speed generator 105 and the three-phase detection currents (Iu, Iv, Iw) detected by the current sensor 104. Outputs voltage (Vu*, Vv*, Vw*).

The power conversion circuit 103 performs PWM (Pulse Width Modulation) control based on the three-phase command voltages (Vu*, Vv*, and Vw*) output from the control unit 102 to generate a pulse-phase output voltage. Drive the motor 101. The current sensor 104 detects the current flowing through each phase of the motor 101 and outputs three-phase detection currents (Iu, Iv, Iw).

In the control unit 102, the command speed (ωr*) provided from the command speed generation unit 105 is multiplied by the gain “motor pole number (P/2)” in the gain multiplier unit 106 to obtain the electric angular velocity (ω1*). ) is calculated.

In the command voltage calculation unit 107, a preset d-axis command current (Id*), a q-axis command current (Iq*) calculated from the q-axis detection current (Iqc), an electric angular velocity (ω1*), and a motor Based on the set values of the constants, the d-axis and q-axis command voltages (Vdc*, Vqc*) are calculated.

The torque pulsation suppression control unit 108 calculates each average value (Idc￣, Iqc￣) by averaging the d-axis and q-axis detection currents (Idc, Iqc), and calculates the electric angular velocity (ω1*), Idc￣, Based on Iqc￣, the amplitude values of the pulsation components of the induced voltage coefficients on the d-axis and q-axis (Kehd*￣, Kehq*￣), the rotor position (θdc), and the set values of the motor constants, the d-axis and Calculate the q-axis voltage correction command (ΔVd*, ΔVq*).

The parameter estimation unit 109 generates a sine signal and a cosine signal based on the rotor position (θdc), and uses the sine signal and cosine signal to determine the pulsation components of the d-axis and q-axis detection currents (Idc, Iqc). Extract information about In addition, the amplitude values (Kehd*￣, Kehq*￣) of the pulsation components of the induced voltage coefficients on the d-axis and q-axis are estimated so that the pulsation components of the d- and q-axis detection currents (Idc, Iqc) are reduced.

In the addition unit 110 including the adders 110a and 110b, the d-axis and q-axis command voltages (Vdc*, Vqc*) calculated by the command voltage calculation unit 107 and the torque pulsation suppression control unit 108 calculate By adding the d-axis and q-axis voltage correction commands (ΔVd*, ΔVq*) respectively, the corrected d-axis and q-axis command voltages (Vdc**, Vqc**) are calculated to suppress torque pulsation.

In the rotor position estimation unit 111, d-axis and q-axis command voltages (Vdc*, Vqc*), d-axis and q-axis detection currents (Idc, Iqc), electric angular velocity (ω1*), and motor constant Based on the setting value, calculate the axis error (Δθc), which is the phase difference between the control axis (dc axis) and the magnetic flux axis (d axis) of the motor. Then, the electric angular velocity (ω1) is controlled so that Δθc becomes zero using PLL (Phase Locked Loop), and the rotor position (θdc) is calculated by integrating the obtained ω1. In other words, this embodiment configures sensorless vector control that does not require a position sensor.

In the dq/3-phase conversion unit 112, based on the rotor position (θdc), the d-axis and q-axis command voltages (Vdc**, Vqc**) are converted into three-phase command voltages (Vu*, Vv*, Vw). Convert to *). Additionally, the three-phase/dq conversion unit 113 converts the three-phase detection currents (Iu, Iv, Iw) into d-axis and q-axis detection currents (Idc, Iqc) based on the rotor position (θdc). .

The above is the basic configuration of this embodiment. Next, the principle of control operation will be explained.

In the command voltage calculation unit 107, set values of the d-axis command current (Id*), q-axis command current (Iq*), electric angular velocity (ω1*), and motor constant according to the following equation (1): Based on this, calculate the d-axis and q-axis command voltages (Vdc*, Vqc*).

In equation (1), R represents the winding resistance, Ld represents the d-axis inductance, Lq represents the q-axis inductance, Ke represents the induced voltage coefficient, and the superscript letter * represents the setting value of each motor constant.

In the command voltage calculation unit 107, a preset constant value is used as the d-axis command current (Id*), and a low-pass filtering value is applied to the q-axis detection current (Iqc) as the q-axis command current (Iq*). Use to perform the calculation of equation (1). From this, in a normal state in which the motor 101 is driven at a constant speed, Id* and Iq* become constant, and the d-axis and q-axis command voltages (Vdc* and Vqc*) also become constant.

In the rotor position estimation unit 111, according to equation (2) below, d-axis and q-axis command voltages (Vdc*, Vqc*), d-axis and q-axis detection currents (Idc, Iqc), and electric Based on the angular velocity (ω1*) and the set value of the motor constant, the axis error (Δθc) is calculated.

In equation (2), ω1 is the electrical angular velocity, and is a signal obtained by adjusting the electrical angular velocity (ω1*) so that the axis error (Δθc) becomes zero by the PLL.

The rotor position estimation unit 111 calculates the rotor position θdc by integrating the electric angular velocity ω1.

Here, in the case of a motor containing a distortion component in the induced voltage, the torque (τm) is expressed by the following equation (3).

In equation (3), Kehd represents the pulsation component of the induced voltage coefficient on the d-axis, and Kehq represents the pulsation component of the induced voltage coefficient on the q-axis. Additionally, terms 1 and 2 of equation (3) correspond to the effective torque component contributing to rotation of the motor, and terms 3 and 4 correspond to the pulsation torque component.

When the d-axis command current (Id*) is set to zero, the first and third terms of equation (3) are zero, so equation (3) can be rewritten as equation (4).

In equation (4), the q-axis current (Iq_opt) for suppressing torque pulsation is expressed by the following equation (5).

In equation (5), ΔIq (=-(Kehq/Ke)·Iq￣) represents the correction current. Additionally, Iq￣ is the average value of the q-axis current (Iq).

By substituting equation (5) into equation (4), the following equation (6) can be obtained.

In equation (6), the first term corresponds to the effective torque component contributing to rotation of the motor, and the second term corresponds to the pulsation torque component.

In equation (4), when the correction current (ΔIq) is not applied (Iq=Iq￣), the torque pulsation component becomes “Kehq·Iq￣”, whereas when the correction current (ΔIq) is applied, From equation (6), it can be seen that the torque pulsation component is “- (Kehq^2)/Ke·Iq￣”. That is, by passing the current (Iq_opt) shown in equation (4), torque pulsation can be reduced to the ratio of “Kehq/Ke”.

An operational image of the torque pulsation suppression control will be explained using FIGS. 2 and 3.

Figure 2 shows the operating waveform when the correction current (ΔIq) is not applied (Id = 0, Iq = Iq￣) (in the figure, Eu is the U-phase induced voltage, and Ehu is the distortion of the U-phase induced voltage. Indicates ingredients). In the same diagram, the U-phase current (Iu) becomes an ideal sine wave, and the d-axis and q-axis currents (Id, Iq) are constant. However, since the induced voltage contains a distortion component, the motor torque (τm) does not become constant and torque pulsation occurs.

Meanwhile, FIG. 3 shows the operation waveform when the correction current (ΔIq) is supplied. As shown in the figure, the correction current that changes in synchronization with the rotor position is superimposed on the q-axis current (Iq), thereby smoothing the motor torque (τm) and suppressing torque pulsation.

In short, the torque pulsation suppression control unit 108 calculates d-axis and q-axis voltage correction commands (ΔVd*, ΔVq*) that realize the correction current (ΔIq) shown in equation (5). Here, the pulsation components (Kehd, Kehq) of the induced voltage coefficients on the d-axis and q-axis are expressed by the following equation (7).

In equation (7), Kehd￣ and Kehq￣ represent the amplitude value of the pulsation component of the induced voltage coefficient on the d-axis and q-axis, and n represents a positive integer (n=1, 2, 3...), respectively.

Assuming equation (7), the torque pulsation suppression control unit 108 calculates d-axis and q-axis voltage correction commands (ΔVd*, ΔVq*) according to equation (8) below.

In the calculation of equation (8), the sine function (sin(n·θdc)) and the cosine function (cos(n·θdc)) are multiplied, so the d-axis and q-axis voltage correction commands (ΔVd*, ΔVq*) are: It becomes a pulsation signal that changes in synchronization with the rotor position (θdc). By adding these signals to the command voltages (Vdc*, Vqc*) of the d-axis and q-axis in the addition unit 110, the correction current (ΔIq) is supplied and torque pulsation is suppressed.

Additionally, the same operation can be realized even if the adder 110 is provided behind the dq/3-phase converter 112. That is, ΔVd* and ΔVq* may be converted in the dq/3-phase conversion unit 112, and their signals may be added to each of the 3-phase command voltages (Vu*, Vv*, and Vw*).

In the calculation of equation (8), the amplitude values (Kehd*￣, Kehq*￣) of the pulsation components of the induced voltage coefficients on the d-axis and q-axis are required. Since these parameters are different for each motor and are not information available at the time of design, it is necessary to obtain them in advance by conducting preliminary tests, etc. In the present invention, autonomous torque pulsation suppression control that does not require preliminary testing is realized by estimating Kehd*￣ and Kehq*￣ online in the parameter estimation unit 109.

Below, the operating principle of the parameter estimation unit 109, which is a feature of the present invention, will be explained.

First, the d-axis current (Id) during driving in this embodiment is expressed by equation (9).

In equation (9), ωr represents the motor speed.

When the d-axis command current (Id*) is set to zero, from equations (1) and (8), the d-axis command voltage (Vdc**) is expressed as equation (10).

By substituting equation (10) into equation (9), equation (11) can be obtained.

Assuming "0≪ω1*" in equation (11), since "ω1*=(P/2)·ωr", the fourth term that does not include ω1* or ωr can be ignored, so equation (12) You can get it.

In equation (12), assuming that “Iq*=Iq￣” and that there is no error in setting the motor constant, the q-axis current (Iq) corresponds to “Iq￣+ΔIq”, so the “- Lq*·Iq*” and the direct current component “Lq·Iq￣” of the third term are canceled out, and only “Lq·ΔIq” remains. Therefore, equation (12) can be rewritten as equation (13).

From equations (5) and (7), the correction current (ΔIq) is in phase with the pulsation component (Kehq) of the induced voltage coefficient on the q-axis, and is therefore expressed by equation (14).

In equation (14), ΔIq￣ represents the amplitude value of the pulsation component of the q-axis current (Iq).

By substituting equation (14) into equation (13) and assuming “θdc=θd,” equation (15) can be obtained.

In equation (15), assuming “R≪ω1*·Ld” and ignoring the winding resistance (R), equation (16) can be obtained from the relationship between input and output.

From equation (16), since the cos(n·θdc) component of the current (Id) includes the coefficient (a) (=ω1*·(Kehd*￣-Kehd￣)), based on this information, the d-axis It is possible to correct the setting error in the amplitude value (Kehd*￣) of the pulsation component of the induced voltage coefficient of the phase.

Next, the q-axis current (Iq) during driving in this embodiment is expressed by equation (17).

When the d-axis command current (Id*) is set to zero, from equations (1) and (8), the d-axis command voltage (Vd**) is expressed as equation (18).

By substituting equation (18) into equation (17), equation (19) can be obtained.

Assuming “0≪ω1*” in equation (19), “ω1*=(P/2)·ωr”, so terms 1, 4, and 6 that do not include ω1* or ωr can be ignored. Therefore, equation (20) can be obtained.

In equation (20), the d-axis current (Id) included in the second term has only a pulsation component as shown in equation (16). Assuming that the setting error in the amplitude value (Kehd*￣) of the pulsation component of the induced voltage coefficient on the d-axis is eliminated by means of parameter correction, the d-axis current (Id) is expressed by the following equation (21) do.

By substituting equation (21) into equation (20) and assuming that there is no error in setting the motor constant and that “θdc=θd,” equation (22) can be obtained.

In equation (22), assuming “R≪ω1*·Lq” and ignoring the winding resistance (R), equation (23) can be obtained from the relationship between input and output.

From equation (23), since the sin(n·θdc) component of the current (Iq) includes the coefficient (d) (=ω1*·(Kehq*￣-Kehq￣)), based on this information, the q-axis It is possible to correct the setting error in the amplitude value (Kehq*￣) of the pulsation component of the induced voltage coefficient of the phase.

FIG. 4 is a configuration diagram of the parameter estimation unit 109 in this embodiment (FIG. 1). As shown in FIG. 4, the parameter estimation unit 109 in this embodiment includes a pulsation current detection unit 400 and a parameter correction unit 401.

The pulsation current detection unit 400 calculates Idc·cos(n·θdc) and Iqc·sin(n·θdc) based on the d-axis and q-axis detection currents (Idc, Iqc) and the rotor position (θdc). Calculate. In addition, the parameter correction unit 401 determines the amplitude value (Kehd ￣, Kehq*￣) is estimated.

FIG. 5 is a configuration diagram of the pulsation current detection unit 400 in this embodiment (FIG. 4). The pulsating current detection unit 400 includes a cos(n·θdc) signal generator 500, a sin(n·θdc) signal generator 502, and multipliers 501 and 504.

The cos(n·θdc) signal generator 500 calculates cos(n·θdc) based on the rotor position (θdc). The multiplier 501 multiplies the d-axis detection current (Idc) and cos(n·θdc) to calculate Idc·cos(n·θdc).

Similarly, the sin(n·θdc) signal generator 502 calculates sin(n·θdc) based on the rotor position (θdc). Then, in the multiplier 504, the q-axis detection current (Iqc) is multiplied by sin(n·θdc) to calculate Iqc·sin(n·θdc).

FIG. 6 is a configuration diagram of the parameter correction unit 401 in this embodiment (FIG. 4). The parameter correction unit 401 includes integration controllers 600 and 603, initial value setting units 601 and 604, and adders 602 and 605.

The integral controller 600 outputs a correction signal (ΔKehd￣) according to the direct current component of Idc·cos(n·θdc). Then, in the adder 602, the amplitude value (Kehd*￣) of the pulsation component of the induced voltage coefficient on the d-axis is estimated by adding ΔKehd￣ to the initial value (Kehd0￣) set in the initial value setting unit 601. do. Specifically, the calculation of equation (24) below is performed.

In equation (24), KId represents the integral control gain.

Similarly, the integral controller 603 outputs a correction signal (ΔKehq￣) according to the direct current component of Iqc·sin(n·θdc). Then, in the adder 605, the amplitude value (Kehq*￣) of the pulsation component of the induced voltage coefficient on the q-axis is estimated by adding ΔKehq￣ to the initial value (Kehq0￣) set in the initial value setting unit 604. do. Specifically, the calculation of equation (25) below is performed.

In equation (25), KIq represents the integral control gain.

When the parameter estimation unit 109 operates, the direct current components of Idc·cos(n·θdc) and Iqc·sin(n·θdc) become It operates to gradually approach zero. And, as shown in Equations (16) and (23), at the point when these signals converge to zero, the amplitude values (Kehd*￣, Kehq*￣) of the pulsation components of the induced voltage coefficients on the d-axis and q-axis The setup error is removed, and the estimation calculation is completed.

The time until the estimation of the amplitude values (Kehd*￣, Kehq*￣) of the pulsation components of the induced voltage coefficients on the d-axis and q-axis is completed is determined by the integral control gains (KId, It can be adjusted according to the setting of KIq). It is desirable to set KId and KIq so that the time until the estimation of Kehd*￣ and Kehq*￣ is completed is sufficiently longer than the time until the motor speed (ωr) converges to the command speed (ωr*). do.

In the initial value setting units 601 and 604, arbitrary values can be set for the initial values (Kehd0￣, Kehq0￣), and zero may be set.

[Example 2]

With reference to FIGS. 7 and 8, a motor driving device and a control method thereof according to Embodiment 2 of the present invention will be described.

The parameter estimation unit 109 does not necessarily need to process with the same calculation cycle, and may be configured to reduce the calculation load by partially processing with a long calculation cycle.

Fig. 7 is a configuration diagram of the parameter estimation unit 109' in this embodiment, and corresponds to a modification of Embodiment 1 (Fig. 4). In the parameter estimation unit 109' shown in FIG. 7, the pulsating current detection unit 700 is processed in an operation cycle (Ts1), and the parameter correction unit 701 is processed in an operation cycle (Ts2).

FIG. 8 is a diagram showing the configuration of the pulsation current detection unit 700 and the concept of signal processing in this embodiment, and corresponds to a modification of Embodiment 1 (FIG. 5). In this configuration, filters 800 and 801 are added to the pulsating current detection unit 400 shown in FIG. 5. Filters 800 and 801 are, for example, low-pass filters.

As shown in FIG. 8, the d-axis and q-axis detection currents (Idc, Iqc) include nth order pulsation components, and the outputs of the multipliers 501 and 504 include 2nth order pulsation components. For the sake of handling these AC signals with high precision, the pulsation current detection unit 700 needs to be processed with a sufficiently short operation cycle. However, since the signal contains only the direct current component after passing through the filters 800 and 801, the calculation accuracy does not deteriorate even if the next processing unit, the parameter correction unit 701, processes with a long calculation cycle.

From the above, the calculation load can be reduced by setting the calculation cycle Ts2 to be longer than the calculation cycle Ts1 in the parameter estimation unit 109' shown in FIG. 7.

It is desirable that the calculation period Ts2 is set to a value sufficient to realize the desired response speed in the estimation calculation of the amplitude values Kehd*￣ and Kehq*￣.

[Example 3]

With reference to FIG. 9, a motor driving device and a control method thereof according to Embodiment 3 of the present invention will be described.

In a fan motor or the like, if the distortion component of the induced voltage in each phase is taken into account up to the 5th order electrical angle component, the state in which torque pulsation is generated may be sufficiently considered.

Assuming that only the fifth-order electric angle component exists in the distortion component of the induced voltage in each phase, the amplitude value of the pulsation component of the induced voltage coefficient becomes equal on the d-axis and q-axis, and the following equation (26) It is established.

Fig. 9 is a configuration diagram of the parameter correction unit 401' in this embodiment, and corresponds to a modification of Embodiment 1 (Fig. 6). In the parameter correction unit 401', an averaging processing unit 900 is added to the parameter correction unit 401 shown in FIG. 6.

The averaging processing unit 900 performs the calculation shown in equation (27) below.

By performing the calculation shown in equation (27), the estimation errors included in each of the amplitude values (Kehd*￣, Kehq*￣) of the pulsation component of the induced voltage coefficient on the d-axis and q-axis are averaged, thereby improving operation precision. You can.

[Example 4]

4 to 6 of the above-described Embodiment 1, a motor driving device and a control method thereof of Embodiment 4 of the present invention will be described.

If the above equation (26) holds, in the amplitude values (Kehd*￣, Kehq*￣) of the pulsation components of the induced voltage coefficients on the d-axis and q-axis, Kehd*￣ is treated as Kehq*￣, or Kehq* There is no problem even if ￣ is treated as Kehd*￣. From this, in the pulsating current detection unit 400 and the parameter correction unit 401 of Example 1 (FIGS. 5 and 6), either one of the parts estimating Kehd*￣ and Kehq*￣ is deleted, and a single estimation is performed. It may be configured to share the results as Kehd*￣ and Kehq*￣. By configuring in this way, the computational load of the parameter estimation unit 109 of Example 1 (FIG. 4) can be reduced by half, making it possible to apply the present invention even to inexpensive computing devices.

[Example 5]

With reference to Fig. 10, a motor driving device and a control method thereof according to Embodiment 5 of the present invention will be described.

Depending on the motor being driven, a sufficient torque pulsation suppression effect may not be obtained simply by considering a specific n-th order component of the distortion component of the induced voltage. When handling multiple order components, for example, the torque pulsation suppression control section 108 and the parameter estimation section 109 in Example 1 (FIG. 1) may be provided for each component, but at the same time, the computational load As the number increases, there is a possibility that expensive arithmetic processing devices may become necessary.

As a means of solving this, the parameter estimation unit 109 estimates the amplitude values (Kehd*￣, Kehq*￣) of the pulsation components of the induced voltage coefficients on the d-axis and q-axis step by step for each order, and stores the results in a memory, etc. A preservation structure can be considered.

Fig. 10 is a configuration diagram of the motor drive device 100 in this embodiment, and corresponds to a modification of Embodiment 1 (Fig. 1). In this configuration, a memory 1000 is added to the motor drive device shown in FIG. 1. In the memory 1000, the amplitude values (Kehd*￣, Kehq*￣) of the pulsation components of the induced voltage coefficients on the d-axis and q-axis are recorded for each order.

With this configuration, even when handling distortion components of a plurality of induced voltages, there is no need to provide a plurality of parameter estimation units 109, so an increase in the computational load can be suppressed.

[Example 6]

With reference to FIGS. 11 and 12, a motor driving device and a control method thereof according to Embodiment 6 of the present invention will be described.

In Example 1, when deriving the above equation (12) or equation (20), the assumption of “0≪ω1*” is applied, and since “ω1*=(P/2)·ωr”, the parameter estimation unit The operation precision of (109) depends on the motor speed (ωr). Specifically, as ωr decreases, the influence of the terms ignored in equations (11) and (19) becomes more noticeable, and there is a possibility that the operation precision of the parameter estimation unit 109 may deteriorate.

As a means of solving this, a configuration can be considered that estimates the amplitude values (Kehd*￣, Kehq*￣) of the pulsation components of the induced voltage coefficients on the d-axis and q-axis according to the command speed (ωr*).

Fig. 11 is a configuration diagram of the motor drive device 100 in this embodiment, and corresponds to a modification of Embodiment 1 (Fig. 1). In this configuration, a parameter estimation unit 1100 is provided instead of the parameter estimation unit 109 in Fig. 1, and the electric angular velocity (ω1*) is added to the input signal.

Fig. 12 is a configuration diagram of the parameter estimation unit 1100 in this embodiment, and corresponds to a modification of Embodiment 1 (Fig. 4). The parameter estimation unit 1100 shown in FIG. 12 is obtained by adding a determination unit 1200 and multipliers 1201 and 1202 to the parameter estimation unit 109 shown in FIG. 4.

The decision unit 1200 calculates a decision signal Sj that has a value of 0 or 1 based on the electric angular velocity ω1*. And Sj is multiplied by Idc·cos(n·θdc) and Iqc·sin(n·θdc), respectively, in the multipliers 1201 and 1202.

Here, the operating range of the parameter estimation unit 1100 is defined as the lower limit (ω1_min) and upper limit (ω1_max) in the electric angular velocity (ω1*).

When “ω1_min≤|ω1*|≤ω1_max” is satisfied, that is, when the parameter estimation unit 1100 is within the operating range, the determination unit 1200 outputs “Sj=1”. At this time, the calculation results of the multipliers 1201 and 1202 are Idc·cos(n·θdc) and Iqc·sin(n·θdc), respectively, and the parameter correction unit 401 operates based on these signals, thereby and the amplitude values (Kehd*￣, Kehq*￣) of the pulsation component of the induced voltage coefficient on the q-axis are estimated.

Meanwhile, when “|ω1*|<ω1_min or ω1_max <|ω1*|” is satisfied, that is, when the parameter estimation unit 1100 is outside the operating range, the determination unit 1200 outputs “Sj=0”. At this time, since the calculation results of the multipliers 1201 and 1202 are all zero, the previous output values are maintained in the integral controllers 600 and 603 in the parameter correction unit 401, and the estimation of Kehd*￣ and Kehq*￣ is stopped. do.

By configuring in this way, the parameter estimation unit 1100 can be operated only in the range of the predetermined command speed (ωr*), so that it is possible to avoid deterioration in operation precision under conditions where the motor speed (ωr) decreases, for example. there is.

In addition, a reset function is provided in the parameter estimation unit 1100, so that “ω1_min≤|ω1*|≤ω1_max” is satisfied, that is, when the parameter estimation unit 1100 returns to the operating range, Kehd*￣, Kehq* It can be configured to start the estimation of Kehd*￣ and Kehq*￣ again using the value before stopping the estimation of ￣ (the previous value), or it can be configured to start the estimation of Kehd*￣ and Kehq*￣ by returning to the initial value each time. You can configure it to resume.

[Example 7]

With reference to Fig. 13, the outdoor unit of the air conditioner according to Example 7 of the present invention will be described. FIG. 13 shows an example in which the motor drive device according to any of the embodiments of Examples 1 to 6 above is applied to a fan motor system mounted on an outdoor unit of an air conditioner.

The outdoor unit 1300 includes a fan motor drive device 1301, a compressor motor drive device 1302, a fan motor 1303, a fan 1304, a frame 1305, and a compressor device 1306. Equipped with The fan motor drive device 1301 is a motor drive device according to any one of the first to sixth embodiments above.

The operation of the fan motor system in the outdoor unit 1300 will be described. The AC power supply 1307 is connected to the driving device 1302 for the compressor motor. The drive device 1302 for the compressor motor rectifies the supplied alternating voltage (VAC) into a direct current voltage (VDC) and drives the compressor device 1306.

At the same time, the compressor motor drive device 1302 also supplies a direct current voltage (VDC) to the fan motor drive device 1301 and further outputs a motor speed command (ωr*).

The drive device 1301 for the fan motor operates based on the input motor speed command (ωr*) and supplies a three-phase voltage to the fan motor 1303. As a result, the fan motor 1303 drives and the connected fan 1304 rotates. This is the operation of the fan motor system.

In the outdoor unit of an air conditioner, it is common to mount an inexpensive computing device on the fan motor drive device 1301 to reduce costs. Additionally, in many cases, a position sensor is not added to the fan motor 1303. Even in this application, torque pulsation suppression control can be realized by using the motor drive device according to the present invention as a drive device for a fan motor. As a result, vibration to the frame 1305 caused by the fan motor 1303 is reduced, and noise emitted from the outdoor unit 1300 can be reduced.

The motor drive device according to the present invention is very easy to apply because preliminary testing or adjustment work, etc. are unnecessary. In addition, since it is an autonomous torque pulsation suppression control, the present invention can be applied to existing installation equipment where it is difficult to measure motor characteristics.

Additionally, the motor driving device according to the embodiments of Examples 1 to 6 can also be used as a driving device for a compressor motor. In short, the present invention can be applied to any motor drive device whose basic configuration is vector control.

In addition, in the embodiments of Examples 1 to 7, the motor driving device using the position sensorless method was explained as an example, but the present invention can also be applied to the motor driving device provided with position sensors such as an encoder, resolver, and magnetic pole position sensor. It can be applied. For example, even if a position sensor is added to the motor 101 shown in FIGS. 1, 10, and 11, and speed feedback control based on the information of the position sensor is added to the control unit 102, the present invention can be applied.

In addition, instead of each command voltage calculation unit 107 in FIGS. 1, 10, and 11, the difference between the d-axis command current (Id*) and the d-axis detection current (Idc), the q-axis command current (Iq*), and The present invention can be applied even in a configuration including current feedback control based on the deviation of the q-axis detection current (Iqc).

Additionally, according to each embodiment of the present invention, information regarding the distortion component of the induced voltage can be estimated based on the d-axis and q-axis detection currents, which are one of the detection signals. By using a detection signal instead of a command signal, the influence of modeling errors, calculation errors, etc. can be excluded as much as possible, and the above estimation can be performed with high precision. When using a detection signal, there is concern about an increase in cost accompanying the addition of sensors, etc., but most motor drive devices are equipped with means for detecting motor current. In other words, the present invention realizes torque pulsation suppression control that operates autonomously using only existing installed sensors.

Additionally, the present invention is not limited to the above-described embodiments and includes various modifications.

For example, the above embodiment has been described in detail to facilitate understanding of the present invention, and is not necessarily limited to having all the described configurations. Additionally, it is possible to replace part of the configuration of a certain embodiment with a configuration of another embodiment, and it is also possible to add a configuration of another embodiment to the configuration of a certain embodiment. Additionally, for some of the configurations of each embodiment, it is possible to add, delete, or replace other configurations.

100: motor drive device 101: permanent magnet synchronous motor (motor)
102: Control unit 103: Power conversion circuit
104: Current sensor 105: Command speed generator
106: gain multiplier 107: command voltage calculation unit
108: Torque pulsation suppression control unit 109, 109', 1100: Parameter estimation unit
110: Adder 110a, 110b: Adder
111: rotor position estimation unit 112: dq/3-phase conversion unit
113: 3-phase/dq conversion unit 400, 700: Pulsation current detection unit
401, 401', 701: Parameter correction unit
500: cos(n·θdc) signal generator
502: sin(n·θdc) signal generator
501, 504: multiplier 600, 603: integral controller
601, 604: initial value setting unit 602, 605: adder
800, 801: Filter 900: Averaging processing unit
1000: Memory 1200: Judgment unit
1201, 1202: Multiplier 1300: Outdoor unit
1301: Drive device for fan motor 1302: Drive device for compressor motor
1303: fan motor 1304: fan
1305: Frame 1306: Compressor device
1307: AC power ωr: motor speed
ωr*: Command speed ω1*: Electrical angular velocity
ω1: Electrical angular velocity obtained by PLL
Vu*, Vv*, Vw*: 3-phase command voltage
Vdc*, Vqc*: d-axis and q-axis command voltage
ΔVd*, ΔVq*: d-axis and q-axis voltage correction command
Iu, Iv, Iw: 3-phase detection current Id, Iq: d-axis and q-axis current
Idc, Iqc: d-axis and q-axis detection current
θd: rotor position θdc: estimate of rotor position
Δθc: Axial error τm: Motor torque
P: Number of motor poles R: Winding resistance
Ld, Lq: d-axis and q-axis inductance Ke: induced voltage coefficient
Kehd, Kehq: Pulsating components of induced voltage coefficients on d- and q-axes.
Kehd￣, Kehq￣: Amplitude values of Kehd and Kehq
Kehd*￣, Kehq*￣: Estimates of amplitude values (Kehd￣, Kehq￣)
ΔKehd￣, ΔKehq￣: Correction values in estimation calculations of Kehd*￣ and Kehq*￣
Kehd0￣, Kehq0￣: Initial values in estimation operations of Kehd*￣ and Kehq*￣
Sj: Judgment signal VAC: AC voltage
VDC: direct current voltage

Claims (12)

a power conversion circuit that drives a permanent magnet synchronous motor;
a control unit that controls the power conversion circuit and calculates an electric angular velocity;
Equipped with a current sensor that detects a three-phase current flowing through the permanent magnet synchronous motor,
The control unit includes a 3-phase/dq conversion unit that converts the 3-phase detection current detected by the current sensor into a d-axis detection current and a q-axis detection current,
a command voltage calculation unit that calculates a command voltage contributing to driving the permanent magnet synchronous motor;
a rotor position estimation unit that calculates a rotor position of the permanent magnet synchronous motor based on the command voltage and the d-axis detection current and q-axis detection current;
Generate a sine signal and a cosine signal based on the rotor position, extract information about the pulsation component of the d-axis and q-axis detection current using the sine signal and cosine signal, and induce voltage coefficients on the d-axis and q-axis. Estimating the amplitude value of the pulsation component of and correcting a set value related to the distortion component of the induced voltage of the permanent magnet synchronous motor so that at least one of the d-axis detection current and the q-axis detection current pulsation component is reduced, a parameter estimation unit that uses a result of correcting the set value as the set value;
The d-axis and q-axis detection currents are averaged to calculate each average value, the average value of the d-axis and q-axis detection currents, the electric angular velocity, the amplitude value of the pulsation component, and the rotor position, a torque pulsation suppression control unit that calculates a voltage correction command that contributes to reducing the pulsation torque of the permanent magnet synchronous motor based on the set value;
An addition unit that adds the command voltage and the voltage correction command
A motor driving device characterized by having a. The method of claim 1, wherein the parameter estimation unit includes a pulsation current detection unit that detects information about a pulsation component of at least one of the d-axis detection current and the q-axis detection current;
A motor driving device characterized by having a parameter correction unit that corrects the set value based on the calculation result of the pulsation current detection unit. According to paragraph 2,
The pulsation current detector generates a sine signal and a cosine signal based on the estimated value of the rotor position estimation unit,
A motor driving device, characterized in that the sine signal and the cosine signal are multiplied by the d-axis detection current and the q-axis detection current. The method of claim 2, wherein the parameter correction unit integrates the calculation result of the pulsation current detection unit,
A motor driving device characterized in that the set value is corrected by adding the result of the integral calculation to the initial set value for the distortion component of the induced voltage. The method of claim 2, wherein the pulsation current detection unit is processed in a first operation cycle,
Processing the parameter correction unit in a second operation cycle,
A motor driving device, characterized in that the first operation cycle is set to a shorter operation cycle than the second operation cycle. The motor drive according to claim 3, wherein the pulsation current detection unit has a filter that removes pulsation components from the results of multiplying the sine signal and the cosine signal by the d-axis detection current and the q-axis detection current, respectively. Device. The motor drive device according to claim 2, wherein the parameter correction unit has an averaging processing unit that averages the results of separately calculating the set values for the distortion components of the induced voltage on the d-axis and the q-axis. delete The method of claim 1, wherein the control unit has a memory that records the calculation results of the parameter estimation unit,
A motor driving device, characterized in that the torque pulsation suppression control unit is controlled based on data written to the memory. The method of claim 2, wherein the parameter estimation unit has a determination unit that generates a decision signal based on the motor speed of the permanent magnet synchronous motor,
The motor driving device, wherein the parameter correction unit executes or stops correction of the set value based on the determination signal. The method of claim 10, wherein the parameter estimation unit has a reset function,
When the motor speed returns to the operating range of the parameter estimation unit, the value before stopping correction of the set value by the parameter correction unit, or the initial value of the set value is used to set the setting by the parameter correction unit. A motor drive device characterized in that it resumes correction of values. a permanent magnet synchronous motor,
a motor driving device that drives the permanent magnet synchronous motor;
a fan connected to the permanent magnet synchronous motor;
A frame for installing the permanent magnet synchronous motor,
It is an outdoor unit of an air conditioner equipped with a compressor device system,
The outdoor unit of an air conditioner, wherein the motor drive device is the motor drive device according to any one of claims 1 to 7 and 9 to 11.

Images