JP2003199390A - Vector control inverter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To estimate an accurate rotational position by supplying a sine wave current even to a permanent magnet motor containing harmonic components in the induced voltage. <P>SOLUTION: An induction voltage generating means 24 is storing induction voltage data concerning to the induction voltage of a motor 2 and generates induction voltages Ed and Eq based on the induction voltage data, an angular frequency ω and a rotational position θ. An output voltage determining means 27 generates output voltages Vd and Vq by adding voltages Xd and Xq obtained by proportionally integrating the induction voltages Ed and Eq and current differences ΔId and ΔIq. An induction voltage estimating means 28 operates induction voltage errors ΔEds and ΔEqs based on a motor constant, currents Id and Iq, the output voltages Vd and Vq, and the angular frequency ω, and an angular frequency determining means 29 determines the angular frequency ωfrom the induction voltage errors ΔEds and ΔEqs. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vector control inverter device which separates a current of a permanent magnet motor into a d-axis current parallel to a magnetic field and a q-axis current orthogonal to the d-axis current and independently controls them.

[0002]

2. Description of the Related Art In vector control, a motor current is separated into an Id which is a d-axis component parallel to a magnetic field and an Iq which is a q-axis component orthogonal thereto, and these currents Id and Iq are independently controlled. Is. Because of its good controllability, this vector control is used not only for induction motors but also for permanent magnet motors having a permanent magnet in the rotor.

FIG. 7 is a functional block diagram showing the electrical construction of a conventional sensorless vector control inverter device. This inverter device 1
Is a current control means 3 for controlling the current of a permanent magnet motor (hereinafter referred to as a motor) 2 and a rotation position estimation means 4 for estimating the angular frequency (rotation speed) ω and rotation position θ of the rotor of the motor 2. It is configured.

In the current control means 3, the winding currents Iu, Iv of the motor 2 detected by the current detection means 5, 6 are detected.
Are converted into currents Id and Iq on the dq coordinate axes (rotational coordinate axes) by the three-phase / two-phase converter 7 and the vector rotator 8, and the command currents Idr and Iq are respectively subtracted by the subtracters 9 and 10.
Deviations ΔId and ΔIq from qr are obtained. Then, these deviations ΔId and ΔIq are calculated by proportional integrators 11 and 1 respectively.
By inputting to 2, the output voltages Vd and Vq are obtained. The obtained output voltages Vd and Vq are converted into voltage amounts on the stator coordinates by the coordinate converter 13, and are further supplied to the PWM inverter circuit 15 as pulse width modulation signals via the PWM former 14 by a method such as a space vector. Given. As a result, a current according to the command currents Idr and Iqr is supplied to the motor 2.

The vector rotator 8 and the coordinate converter 1
The rotational position θ of the rotor used in No. 3 was once detected directly by arranging a rotational position sensor such as an encoder in the motor 2 in the past, but in recent years, a so-called sensorless method that is estimated from the motor current or the like is used. Has been. That is, in the rotational position estimation means 4, the induced voltage estimation means 16 stores the inductances Ld and Lq and the resistance R as motor constants in advance, and the above currents Id and Iq, the output voltages Vd and Vq and the estimated angle. The frequency ω is input. The induced voltage estimating means 16 calculates the estimated values Eds and Eqs of the induced voltage by the following equations (1) and (2). Note that p used in the formula is a differential operator.

[0006]

[Equation 1]

The angular frequency determining means 17 has an estimated induced voltage E
From ds and Eqs, for example, the angular frequency ω is calculated by the following equation (3).
To estimate. Here, G1 is the reciprocal of the induced voltage constant of the motor 2, and G2 is the gain constant. Estimated angular frequency ω
Is integrated by the integrator 18, and the rotational position θ is obtained.

[0008]

[Equation 2]

According to this position estimation method, since the angular frequency ω is obtained based on the estimated induced voltage Eqs and the estimated induced voltage Eds is controlled to be zero, the rotational position θ is the actual rotation of the motor 2. Has the effect of matching the position. Note that each processing described above is periodically processed by a high speed processor such as a DSP.

[0010]

By the way, in order to improve the motor efficiency by utilizing the reluctance torque, a rotor structure as shown in FIG. 8 in which the permanent magnet 20 is arranged in the rotor core 19 may be adopted. is there. In this case, the motor 2
The induced voltage generated during rotation has a waveform including many harmonics such as fifth, seventh, ... The induced voltage waveform shown in FIG. 3 is a calculation result for the motor 2 having the above rotor structure, and it can be seen that large harmonic components (5th and 7th orders) are superimposed.

Such a harmonic component of the induced voltage causes a fluctuation in the current control loop. For such a motor 2, an inverter device 1 having the conventional configuration shown in FIG.
Even when using, the processing cycle by the processor is short,
If the gains of the proportional integrators 11 and 12 (hereinafter referred to as current gains) are sufficiently high, the motor current is controlled so as to follow the command current and has a sinusoidal waveform.

However, in an actual inverter device, it is desirable to reduce the switching loss of the PWM inverter circuit 15, so that it is desirable to lower the PWM frequency within a range in which electromagnetic noise due to PWM does not cause a problem. Therefore, in synchronization with the PWM cycle. The processing cycle becomes longer. When the processing cycle becomes long, a control delay occurs in the current control loop and the phase margin decreases, so that it becomes necessary to reduce the current gain for stabilization.

In addition to this, for example, Japanese Patent Laid-Open No. 61-
In the case of adopting the detection method described in Japanese Patent No. 262084 or Japanese Patent Application Laid-Open No. 2-197295, that is, the current detection resistor is arranged in the inverter device and the motor current is obtained based on the voltage across the inverter device, the power is detected. Since the ground of the system and the ground of the signal system are common, noise may be mixed in the voltage between both ends, and it is also desirable to reduce the current gain.

However, when the current gain is reduced, the current control loop cannot counteract the harmonic component of the induced voltage and cause the motor current to follow the command current, resulting in distortion of the motor current. FIG. 9 shows (a) output voltages Vd and Vq, and (b) motor current Iu when the current gain is low.
The simulation result of Id, Iq, and (c) generated torque T is shown. The horizontal axis represents the rotational position (electrical angle). The currents Id and Iq fluctuate due to the harmonic components of the induced voltage, but due to the low current gain, the fluctuations result in the output voltage Vd,
It is not reflected in Vq, and the output voltages Vd and Vq hardly change. For this reason, the output voltage Vu remains a sinusoidal waveform even though there is a harmonic component in the induced voltage, and the motor current Iu is distorted due to the influence of the harmonic component. As a result, the generated torque T calculated by the following equation (4)
However, there was a problem that the fluctuation became large.

[0015]

[Equation 3]

Further, the fluctuations of the currents Id and Iq also adversely affect the estimation of the rotational position in the sensorless system. That is, in the above equations (1) and (2),
Although the output voltages Vd and Vq are constant, the motor currents Id and Iq fluctuate, so that the estimated induced voltage Eds,
Eqs fluctuates. As a result, the estimated angular frequency ω and the rotational position θ are also affected, and the inverter device 1
The whole becomes unstable (oscillating) and the operable frequency range is narrowed. In particular, it becomes difficult to operate at low frequency and high load.

In order to prevent this, a low pass filter having a cutoff frequency close to the output frequency (that is, capable of attenuating the fifth harmonic) with respect to the angular frequency ω and the rotational position θ may be added. As a result, the responsiveness deteriorates, and a new problem arises in that it cannot cope with a sudden load change or sudden acceleration / deceleration.

The present invention has been made in view of the above circumstances, and a first object thereof is to provide a vector control inverter device capable of supplying a sine wave current to a permanent magnet motor including a harmonic component in an induced voltage. To provide, the second
It is an object of the present invention to provide a vector control inverter device capable of estimating an accurate rotational position without a sensor even for a permanent magnet motor whose induced voltage contains a harmonic component.

[0019]

In order to achieve the first object, the vector control inverter device according to the first aspect of the present invention makes a current of a permanent magnet motor having a rotor provided with a permanent magnet parallel to a magnetic field. In a vector control inverter device that separates a d-axis current and a q-axis current orthogonal thereto and controls them independently, induced voltage data prepared corresponding to at least harmonic components of the induced voltage of the permanent magnet motor, and An induced voltage generating means for generating a d-axis induced voltage and a q-axis induced voltage of the permanent magnet motor based on an angular frequency and a rotational position of the rotor; and a voltage determined according to a deviation of the d-axis current, The d-axis induced voltage and the q-axis induced voltage generated by the induced voltage generating means are added to the voltage determined according to the deviation of the q-axis current to obtain the d-axis output voltage and Characterized in that an output voltage determining means for determining a q-axis output voltage.

According to this structure, the d-axis induced voltage and the q-axis induced voltage generated by the induced voltage generating means include harmonic components corresponding to the induced voltage of the permanent magnet motor. The shaft induced voltage is applied to the permanent magnet motor as a d-axis output voltage and a q-axis output voltage. As a result, the harmonic component contained in the output voltage of the vector control inverter device and the harmonic component of the induced voltage of the permanent magnet motor are canceled out, and the current fluctuation caused by the harmonic component of the induced voltage of the permanent magnet motor is reduced. Then, the motor current becomes a sine wave.
This reduces fluctuations in generated torque and noise. Also,
Since the voltage determined according to the deviation of the d-axis current and the voltage determined according to the deviation of the q-axis current are added to the d-axis output voltage and the q-axis output voltage, respectively, a current that makes the current deviation zero is added. Feedback control is performed.

The present invention is characterized in that in addition to the current feedback control, the induced voltage containing the harmonic components of the permanent magnet motor is fed forward, and the induced voltage is generated for the two-phase voltage. Instead of the above, the configuration may be such that an induced voltage is generated for three-phase voltages as described in claim 2.

Further, in order to achieve the above second object,
The vector control inverter device according to claim 3 induces at least an induced voltage error of the d-axis of the permanent magnet motor based on the voltage determined according to the deviation of the d-axis current and the d-axis current and the q-axis current. It is characterized by further comprising voltage estimating means and angular frequency / position determining means for determining the angular frequency and rotational position of the rotor based on at least the d-axis induced voltage error.

According to this configuration, the voltage determined according to the deviation of the d-axis current, that is, the voltage other than the d-axis induced voltage in the d-axis output voltage is a current forming component that determines the d-axis current and the q-axis current. To work. The difference between the voltage determined according to the deviation of the d-axis current that is added when generating the d-axis output voltage and the d-axis current forming voltage calculated based on the d-axis current and the q-axis current is , D-axis induced voltage error. This d-axis induced voltage error has a value corresponding to the displacement of the rotational position, and since the influence of the harmonic component of the induced voltage is removed, the angular frequency of the rotor can be accurately determined based on this. Further, the angular frequency can be integrated to obtain an accurate rotational position.

Further, the angular frequency and the rotational position of the rotor may be determined based on the q-axis induced voltage error together with the d-axis induced voltage error (claim 4). In this case, the q-axis induced voltage error has a value corresponding to the deviation of the angular frequency.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows an electrical configuration of the vector control inverter device by functional blocks, and the same components as those in FIG. 7 are designated by the same reference numerals. The sensorless inverter device 21 includes a current control unit 22 that controls the current of the permanent magnet motor 2 and a rotation position estimation unit 23 that estimates the angular frequency (rotation speed) ω and the rotation position θ of the rotor of the motor 2. It is configured.

The functions of the inverter device 21 except the current detecting means 5 and 6 and the PWM inverter circuit 15 are DSP according to the control program stored in the memory.
It is designed to be executed by high-speed processors such as. The control cycle is set equal to the PWM cycle. The motor 2 driven by the inverter device 21 is
Rotor core 1 so that reluctance torque can be generated
The permanent magnet 20 is embedded in the rotor 9 as shown in FIG.

The induced voltage generating means 24 provided in the current control means 22 stores the induced voltage data regarding the induced voltage of the motor 2 in a memory or the like, and the induced voltage data and the angle input from the rotational position estimating means 23 are stored. The d-axis induced voltage Ed and the q-axis induced voltage Eq are generated based on the frequency ω and the rotational position θ.

The subtractors 9 and 10 are respectively provided with the command current Id.
The currents Id and Iq are subtracted from r and Iqr to obtain the deviation ΔId,
ΔIq is obtained, and the proportional integrators 11 and 12 perform proportional integral calculation on the deviations ΔId and ΔIq, respectively, and the voltages Xd and Xq (corresponding to the voltage determined according to the current deviation), which are current forming voltages.
Is output. The adder 25 adds the induced voltage Ed and the voltage Xd to obtain the output voltage Vd, and the adder 26 adds the induced voltage Eq and the voltage Xq to obtain the output voltage Vq. . These output voltages Vd and Vq are given to the coordinate converter 13. Here, the subtractor 9, 10, the proportional integrator 11, 12 and the adder 25, 26 constitute an output voltage determining means 27.

On the other hand, the induced voltage estimating means 28 provided in the rotational position estimating means 23 stores the inductances Ld, Lq and the resistance R, which are motor constants, in a memory or the like, and these motor constants, currents Id, Iq, Output voltage V
Based on d, Vq and the estimated angular frequency ω, the induced voltage error ΔEds on the d-axis and the induced voltage error ΔEqs on the q-axis.
It is designed to calculate and. Then, the angular frequency determination means 29 determines the angular frequency ω from these induced voltage errors ΔEds and ΔEqs, and the integrator 18 integrates the determined angular frequency ω to obtain the rotational position θ to obtain the vector rotator 6 and the coordinates. It is adapted to be supplied to the converter 13. The angular frequency determining means 29 and the integrator 18 correspond to the angular frequency / position determining means in the present invention.

Next, the operation of the current control means 22 and the rotational position estimating means 23 will be described with reference to FIGS. (1) Operation of the current control means 22 The induced voltage E of the motor 2 having the rotor structure shown in FIG.
u, Ev, and Ew include harmonic components such as fifth-order, seventh-order, ... In addition to the fundamental wave component. This induced voltage Eu, E
v and Ew can be expressed by superimposing the fundamental wave component and the main harmonic components (5th and 7th) as shown in the following equation (5). Here, the coefficients E1, E5, E7
Is the voltage amplitude of each order component and can be obtained by testing.

[0031]

[Equation 4]

The induced voltages Eu, Ev, and Ew are three-phase / two-phase converted according to the following expression (6), and further rotational coordinate conversion is performed according to the expression (7) to obtain expressions (8) and (9).
The induced voltages Ed and Eq on the dq coordinate axes shown by the formula are obtained. Here, K0 is the induced voltage constant of the fundamental wave, K1, K2
Are the induced voltage constants of the harmonic components on the d-axis and the q-axis, respectively, and these K0, K1, and K2 correspond to the induced voltage data.

[0033]

[Equation 5]

FIG. 2 shows the results of calculations performed using the above equations (5) to (9). The vertical axis represents voltage, and the horizontal axis represents rotational position (electrical angle) θ. As shown in equations (8) and (9), the induced voltages Ed and Eq pulsate at a frequency that is six times the fundamental wave. . The induced voltage constants K1 and K2 described above are values obtained by dividing the amplitudes of the induced voltages Ed and Eq shown in FIG. 2 by the angular frequency ω. The induced voltage generating means 24 inputs the angular frequency ω and the rotational position θ input from the rotational position estimating means 23, and uses the equations (8) and (9) to induce the induced voltage E.
Calculate d and Eq.

FIG. 3 shows the calculation results of voltage, current and torque for the inverter device 21. here,
In (a), the u-phase output voltage Vu excluding the PWM component, the induced voltages Ed and Eq output by the induced voltage generating means 24, and the output voltages Vd and Vq output by the output voltage determining means 27 are shown.
And (b) shows the current Iu flowing through the motor 2 and the currents Id, Iq output by the vector rotating machine 8,
The generated torque T calculated according to the equation (4) is shown in (c). The horizontal axis represents the rotational position (electrical angle) θ. In this calculation, in order to effectively use the reluctance torque to obtain the maximum torque, the current Id (command current Id
r) is set to a predetermined negative value.

When the current control means 22 is used, the output voltage V
d and Vq are values obtained by adding the induced voltages Ed and Eq to the voltages Xd and Xq determined by the current deviations ΔId and ΔIq, respectively. Therefore, the output voltages Vd and Vq include almost the same voltage as the induced voltage of the motor 2, and the induced voltages of both are canceled. As a result, of the output voltages Vd and Vq, only the voltages Xd and Xq act as current forming components, and the motor currents Iu, Iv, and Iw have sinusoidal waveforms without being influenced by the induced voltage. Then, the currents Id and Iq obtained by the rotational coordinate conversion become constant, so that the fluctuation due to the harmonic of the induced voltage can be eliminated from the current feedback loop. As a result, the currents Id and Iq
The fluctuation of the torque T calculated based on the above is significantly smaller than that of FIG. 9C showing the torque T in the conventional configuration.

FIG. 4 is a vector diagram showing the voltage and current of the motor 2. (A), (b) has shown the case where the motor 2 was driven using the inverter apparatus 21 of this embodiment and the inverter apparatus 1 of a conventional structure, respectively. The amplitude and phase of the induced voltage vector E (Ed, Eq) fluctuates around the q axis due to its harmonic component. In the case of the present embodiment shown in (a), the output voltage vector V (Vd,
Since Vq) is a voltage including the induced voltage vector E (Ed, Eq), the current forming voltage vector X (Xd, Xq) and the current vector I (Id, Iq) are substantially constant.
On the other hand, in the case of the conventional configuration shown in (b), since the output voltage vector V (Vd, Vq) is almost constant, the current forming voltage vector X (Xd, Xq) and the current vector I (Id, Iq). ) Will fluctuate.

(2) Operation of the rotational position estimating means 23 The induced voltage estimating means 28 uses the following equation (10) and (1)
The induced voltage errors ΔEds and ΔEqs are calculated by the equation 1). P used in the formula is a differential operator.

[0039]

[Equation 6]

These induced voltage errors ΔEds, ΔEqs
Means the difference between the actual angular frequency and rotational position of the motor 2 and the angular frequency ω and rotational position θ obtained by the rotational position estimating means 23. In particular, the induced voltage error ΔEds corresponds to the deviation of the rotational position θ, and the induced voltage error ΔEqs corresponds to the magnitude of the induced voltage, that is, the deviation of the angular frequency ω. Further, as described above, the voltages Xd and Xq and the currents Id and Iq are not affected by the harmonic components of the motor induced voltage, and thus (1
0) and induced voltage error Δ obtained by the equation (11)
Eds and ΔEqs are not affected by the harmonic component of the motor induced voltage.

The angular frequency determining means 29 determines the induced voltage error Δ
Using Eds and ΔEqs, for example, the angular frequency ω is estimated by the following equation (12). Here, Ga and Gb are gain constants. Further, the rotational position θ is obtained by integrating the obtained angular frequency ω by the integrator 18.

[0042]

[Equation 7]

From this equation (12), the induced voltage error ΔE
The angular frequency ω is determined so that qs becomes zero, and the induced voltage Eq output from the induced voltage generating means 24 is the motor 2
It acts so as to match the induced voltage of the q-axis of. Further, since the rotational position θ is adjusted by the induced voltage error ΔEds via the angular frequency ω, the induced voltage Ed output from the induced voltage generating means 24 matches the induced voltage of the d-axis of the motor 2. To work. As a result, the angular frequency and the rotational position of the motor 2 are obtained as the angular frequency ω and the rotational position θ, respectively.

As described above, the inverter device 21
The induced voltage generation means 24 provided in stores the induced voltage data corresponding to the induced voltage of the motor 2 to be driven, and when the motor 2 is rotationally driven, the induced voltage data and the angular frequency ω.
And the induced voltage E of the motor 2 based on the rotational position θ
d and Eq are generated. Since the induced voltages Ed and Eq are applied to the motor 2 as the output voltages Vd and Vq, the harmonic components of the induced voltages Ed and Eq included in the output voltages Vd and Vq and the harmonic components of the actual induced voltage of the motor 2 are included. Are canceled out, and the current fluctuation due to the harmonic component of the induced voltage of the motor 2 is reduced. As a result, the motor currents Iu, Iv, I
Since w has a sinusoidal waveform, fluctuations in generated torque and noise can be reduced. Further, since the voltages Xd and Xq determined according to the current deviation are added to the output voltages Vd and Vq, current feedback control for making the current deviation zero is also performed.

Further, the induced voltage estimating means 28 calculates the induced voltage errors ΔEds and ΔEqs by using the voltages Xd and Xq which are not affected by the harmonic components of the motor induced voltage and the currents Id and Iq and the angular frequency ω. Therefore, the angular frequency ω and the rotational position θ estimated by using the induced voltage errors ΔEds and ΔEqs have accurate values with no fluctuation, and it is possible to prevent a decrease in motor efficiency due to the estimation error.

Therefore, the inverter device 21 of the present embodiment.
Is a motor whose induced voltage contains a large harmonic component, for example, a rotor core 19 and a permanent magnet 2 as shown in the motor 2.
It is suitable for driving a high-efficiency motor that embeds 0 to generate a reluctance torque. Further, since it is not affected by the harmonic component of the induced voltage, it is not necessary to add a low pass filter, and the response can be improved.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. Figure 5
Shows the electrical configuration of the current control means of the vector control inverter device by functional blocks, and the same components as those in FIG. 1 are designated by the same reference numerals. The rotational position estimating means (not shown) has the same configuration as the rotational position estimating means 23 in the first embodiment.

Current control means 31 of the inverter device 30
, The induced voltage generating means 32 stores the induced voltage data of three phases of the motor 2, and the induced voltage data and the angular frequency ω and the rotational position θ input from the rotational position estimating means 23.
The induced voltages Eu, Ev, Ew of each phase of uvw are generated based on

The voltages Xd and Xq output from the proportional integrators 11 and 12 are converted into voltage amounts on the rotating coordinates by the coordinate converter 13, and further the three-phase voltage Xu, by the two-phase / three-phase converter 33. It is converted into Xv and Xw. Adders 34, 3
Reference numerals 5 and 36 add output voltages Vu, Vv, V by adding induced voltages Eu, Ev, Ew and voltages Xu, Xv, Xw, respectively.
It is designed to ask for w. These subtractors 9, 10,
The proportional integrators 11, 12, the coordinate converter 13, the two-phase / three-phase converter 33, and the adders 34, 35, 36 constitute an output voltage determining means 37. Output voltage Vu, Vv,
Vw is the PWM generator 38 by a method such as triangular wave comparison.
Is given to the PWM inverter circuit 15 as a pulse width modulation signal.

The induced voltage generating means 32 generates three-phase induced voltages Eu, Ev, Ew by the calculation based on the following equation (13). Here, K1, K2, and K3 are coefficients E1, E5, and E5 of the equation (5) obtained by rotating the motor 2, respectively.
It is a value obtained by dividing E7 by the angular frequency ω.

[0051]

[Equation 8]

In this embodiment, three-phase induced voltages Eu, E
Two-phase induced voltages Ed, E at the point of generating v, Ew
Although it is different from the first embodiment that generates q, the operation and effect are similar to those of the first embodiment, and a sinusoidal current can be supplied to the motor 2.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. Figure 6
Shows the electrical configuration of the vector control inverter device by functional blocks, and the same components as those in FIG. 1 are designated by the same reference numerals. This inverter device 39 is
In contrast to the inverter device 21 described in the first embodiment,
Rotational position estimating means 40 with a structure including a speed control loop
The configuration is different. The rotational position estimating means 40 has a simplified configuration with respect to the rotational position estimating means 23 of the first embodiment.

In the speed control loop, the subtractor 41 calculates the deviation Δω between the command angular frequency ω 0 and the estimated angular frequency ω, and the deviation Δω is input to the proportional integrator 42 and the dq distributor 43, and the command current Idr, Iqr is to be determined.

The induced voltage estimation means 44 of the rotational position estimation means 40 calculates the d-axis induced voltage error ΔEds by the above-mentioned equation (10). The angular frequency determining means 45 estimates the angular frequency ω by using the induced voltage error ΔEds by the proportional-plus-integral calculation according to the following equation (14). Where Gx,
Gy is a proportional gain and an integral gain, respectively. Further, the rotational position θ can be obtained by integrating the obtained angular frequency ω.

[0056]

[Equation 9]

Since the rotational position θ is adjusted via the angular frequency ω by the induced voltage error ΔEds, the induced voltage Ed output by the induced voltage generating means 24 is d of the motor 2.
It works to match the induced voltage on the shaft. As a result, the angular frequency and the rotational position of the motor 2 are obtained as the angular frequency ω and the rotational position θ, respectively. Also in this embodiment, since the induced voltage error ΔEds does not include the harmonic component of the induced voltage of the motor 2, the angular frequency ω and the rotational position θ can be accurately estimated, and the same effect as the first embodiment can be obtained. Can be obtained.

(Other Embodiments) The present invention is not limited to the above-described embodiments, and the following modifications or expansions are possible. In each of the embodiments, the rotational position estimating means 23 and 40 are provided to obtain the rotational position θ without the rotational position sensor. However, the rotational position θ may be obtained using a rotational position sensor such as a resolver or an encoder. However, the configurations, actions, and effects of the current control means 22 and 31 do not change. In each of the embodiments, the induced voltage generating means 24, 32 are described as a part of the current control means 22, 31, but the induced voltage generating means 24, 32 may be considered as a part of the rotational position estimating means 23, 40. . A speed control loop may be added to each of the first and second embodiments.

In order to reduce the noise mixed in from the current detecting means 5 and 6, for example, a low pass having a cutoff frequency close to the processing cycle with respect to the angular frequency ω, the rotational position θ, the currents Id, Iq, the voltages Xd, Xq, etc. A filter may be added. The addition of this low-pass filter does not violate the gist of the present invention. A motor temperature detector that detects the temperature of the motor 2 may be provided to correct the arithmetic constants of the induced voltage generating means 24 and 32. For example, if the detected temperature rises according to the magnetic flux density temperature coefficient of the permanent magnet 20 (8)
K0, K1, and K2 in the equation (9) are reduced. Thereby, a more accurate induced voltage can be generated. The induced voltage generating means 24 and 32 generate the fundamental wave component and the harmonic component of the induced voltage, but generate only the harmonic component of the induced voltage or only the harmonic component of a specific order that greatly affects the torque fluctuation. It may be done.

[0060]

As is apparent from the above description, the vector control inverter device of the present invention includes the induced voltage generating means for generating the induced voltage of the permanent magnet motor and the induced voltage for the voltage determined according to the deviation of the current. Since the output voltage determining means for determining the output voltage by adding the induced voltage generated by the voltage generating means is provided, the harmonic component included in the output voltage and the harmonic component of the induced voltage of the permanent magnet motor are This offsets the current fluctuation caused by the harmonic components and reduces the motor current into a sinusoidal waveform, which reduces fluctuations in generated torque and noise.

Further, an induced voltage estimating means for obtaining at least a d-axis induced voltage error of the permanent magnet motor based on the voltage determined according to the current deviation and the d-axis current and the q-axis current, and at least the d-axis induced voltage error. Since the angular frequency / position determining means for determining the angular frequency and the rotational position of the rotor based on the above are provided, it is possible to accurately estimate the rotational position without using the rotational position sensor, and to reduce the motor efficiency due to the estimation error. Can be prevented.

[Brief description of drawings]

FIG. 1 is a diagram showing the electrical configuration of a vector control inverter device according to a first embodiment of the present invention by functional blocks.

FIG. 2 is a diagram showing a calculation result of voltage with respect to a rotational position of a motor.

FIG. 3 is a diagram showing calculation results of voltage, current, and torque when driving a motor.

FIG. 4 is a diagram showing a voltage vector and a current vector of a motor.

FIG. 5 is a diagram showing, by functional blocks, an electrical configuration of a current control means of a vector control inverter device according to a second embodiment of the present invention.

FIG. 6 is a view corresponding to FIG. 1 showing a third embodiment of the present invention.

FIG. 7 is a diagram corresponding to FIG. 1 showing a conventional technique.

FIG. 8 is a cross-sectional view of the rotor

FIG. 9 is a view corresponding to FIG.

[Explanation of symbols]

2 is a permanent magnet motor, 21, 30 and 39 are vector control inverter devices, 24 and 32 are induced voltage generating means, 2
Reference numerals 7 and 37 are output voltage determining means, 28 and 44 are induced voltage estimating means, and 29 and 45 are angular frequency determining means.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H02P 6/02 351G F term (reference) 5H560 BB04 BB12 DA14 DB14 DC12 EB01 EC01 RR01 XA02 XA04 XA12 XA13 5H576 BB04 DD02 DD07 EE01 EE11 GG03 GG04 HB01 JJ24 LL14 LL22 LL46

Claims (4)

[Claims] 1. A vector control inverter device in which a current of a permanent magnet motor having a rotor provided with a permanent magnet is separated into a d-axis current parallel to a magnetic field and a q-axis current orthogonal to the d-axis current and independently controlled. A d-axis induced voltage and a q-axis of the permanent magnet motor based on the induced voltage data prepared corresponding to at least harmonic components of the induced voltage of the permanent magnet motor, and the angular frequency and rotational position of the rotor. Induced voltage generating means for generating an induced voltage, and d-axis induction generated by the induced voltage generating means for the voltage determined according to the deviation of the d-axis current and the voltage determined according to the deviation of the q-axis current, respectively. And a q-axis induced voltage are added to determine the d-axis output voltage and the q-axis output voltage. Location. 2. Vector control in which a current of a three-phase permanent magnet motor having a rotor provided with a permanent magnet is separated into a d-axis current parallel to a magnetic field and a q-axis current orthogonal to the d-axis current and independently controlled. In the inverter device, three-phase induction of the permanent magnet motor is performed based on the induced voltage data prepared corresponding to at least harmonic components of the induced voltage of the permanent magnet motor, and the angular frequency and rotational position of the rotor. Induced voltage generating means for generating a voltage, and the induced voltage for each phase obtained by three-phase conversion of the voltage determined according to the deviation of the d-axis current and the voltage determined according to the deviation of the q-axis current. A vector control inverter device, comprising: output voltage determining means for adding three-phase induced voltages generated by the voltage generating means to determine an output voltage of the three phases. 3. Induction voltage estimation means for determining at least a d-axis induced voltage error of the permanent magnet motor based on the voltage determined according to the deviation of the d-axis current and the d-axis current and the q-axis current, and at least the d. The vector control inverter device according to claim 1 or 2, further comprising: an angular frequency / position determining means for determining an angular frequency and a rotational position of the rotor based on a shaft induced voltage error. 4. The induced voltage estimating means, in addition to the d-axis induced voltage error, a q-axis induced voltage error based on the voltage determined according to the deviation of the q-axis current and the d-axis current and the q-axis current. The angular frequency / position determining means is configured to determine the angular frequency and the rotational position of the rotor based on the d-axis induced voltage error and the q-axis induced voltage error. The vector control inverter device according to claim 3, wherein