阅读说明：本技术 交流旋转机的控制装置及交流旋转机的控制方法 (Control device for AC rotary machine and control method for AC rotary machine ) 是由 蜂矢阳祐 伊藤正人 丸山阳央 河原邦宏 于 2019-04-23 设计创作，主要内容包括：在旋转机(1)的无传感器控制中,如果由制造误差引起的UVW各相的电感的波动变大,则在各相的检测电流之间产生不平衡。由此,转子的磁极位置的推定误差变大,定位精度下降。对控制单元(5)或者磁极位置运算单元(6)设置赋予与各相的旋转机常数相应的增益的校正滤波器(561、562、563、621、622、623),对在各相的检测电流之间产生的不平衡进行校正。(In sensorless control of a rotary machine (1), if fluctuation of inductance of each phase of UVW caused by manufacturing error becomes large, unbalance occurs between detection currents of each phase. This increases an estimation error of the magnetic pole position of the rotor, and decreases positioning accuracy. Correction filters (561, 562, 563, 621, 622, 623) for applying gains corresponding to the rotating machine constants of the respective phases are provided to the control unit (5) or the magnetic pole position calculation unit (6), and the imbalance generated between the detection currents of the respective phases is corrected.)

1. A control device for an AC rotary machine, comprising:

a control unit that generates a fundamental wave voltage command for driving a rotary machine, generates a high-frequency voltage command for estimating a magnetic pole position of a rotor of the rotary machine, and calculates a voltage command using the fundamental wave voltage command and the high-frequency voltage command;

a voltage applying unit that applies a voltage to the rotary machine based on the voltage command;

a current detection unit that detects a current of each phase of the rotary machine;

magnetic pole position calculation means for extracting high-frequency currents of respective phases from the detected currents of the rotating machine and calculating estimated positions of the magnetic pole positions; and

an imbalance adjuster that adjusts imbalance of the high-frequency currents between the phases,

the magnetic pole position calculation means calculates an estimated position of a magnetic pole of a rotor of the rotary machine using the high-frequency current with the imbalance adjusted.

2. The control device of an AC rotary machine according to claim 1,

the imbalance adjuster adjusts imbalance of the high-frequency currents between the phases by applying a gain based on a rotating machine constant of each phase of the rotating machine to the high-frequency currents of each phase.

3. The control device of an AC rotary machine according to claim 1,

the imbalance adjuster gives a gain based on a rotating machine constant of each phase to at least 2-phase high-frequency voltage commands among the high-frequency voltage commands, and adjusts imbalance of high-frequency currents between phases.

4. The control device of an AC rotary machine as claimed in claim 2 or 3,

the gain is a constant of proportionality.

5. A control method of an AC rotary machine using the control device of the AC rotary machine according to claim 1 or 2,

the control method of the alternating-current rotating machine comprises the following steps:

a first step of rotating a rotor of the rotating machine to a first magnetic pole position and applying a high-frequency voltage based on the high-frequency voltage command to the rotor, thereby obtaining a high-frequency current amplitude at the first magnetic pole position by the current detection means;

calculating high-frequency currents at the second and third magnetic pole positions based on the high-frequency current at the first magnetic pole position acquired in the first step, and calculating a gain based on the rotating machine constant of each phase;

giving the calculated gain based on the constant of the rotating machine of each phase, and adjusting the imbalance of the high-frequency current between the phases of the rotating machine; and

and calculating an estimated position of a magnetic pole of a rotor of the rotary machine using the adjusted high-frequency current, and driving the rotary machine based on the estimated position of the magnetic pole.

6. A control method of an AC rotary machine using the control device of the AC rotary machine according to claim 1 or 2,

the control method of the alternating-current rotating machine comprises the following steps:

a first step of rotating a rotor of the rotating machine to a first magnetic pole position and applying a high-frequency voltage based on the high-frequency voltage command to the rotor, thereby obtaining a high-frequency current amplitude at the first magnetic pole position by the current detection means;

a second step of rotating a rotor of the rotary machine to a second magnetic pole position and applying a high-frequency voltage based on the high-frequency voltage command to the rotor, thereby obtaining a high-frequency current amplitude at the second magnetic pole position by the current detection means;

a third step of rotating a rotor of the rotary machine to a third magnetic pole position and applying a high-frequency voltage based on the high-frequency voltage command to the rotor, thereby obtaining a high-frequency current amplitude at the third magnetic pole position by the current detection means;

calculating a gain based on a rotating machine constant of each phase based on the high-frequency current amplitude at each magnetic pole position acquired in the first step, the second step, and the third step;

giving the calculated gain based on the constant of the rotating machine of each phase, and adjusting the imbalance of the high-frequency current between the phases of the rotating machine; and

and calculating an estimated position of a magnetic pole of a rotor of the rotary machine using the adjusted high-frequency current, and driving the rotary machine based on the estimated position of the magnetic pole.

7. A control method of an AC rotary machine using the control device of the AC rotary machine according to claim 1 or 3,

the control method of the alternating-current rotating machine comprises the following steps:

a first step of rotating a rotor of the rotary machine to a first magnetic pole position, and adjusting an amplitude of the high-frequency voltage command so that a predetermined high-frequency current amplitude command matches the amplitude of the high-frequency current, thereby obtaining a high-frequency voltage amplitude at the first magnetic pole position;

a second step of rotating a rotor of the rotary machine to a second magnetic pole position, and adjusting an amplitude of the high-frequency voltage command so that the high-frequency current amplitude command matches an amplitude of the high-frequency current, thereby obtaining a high-frequency voltage amplitude at the second magnetic pole position;

a third step of rotating a rotor of the rotary machine to a third magnetic pole position, and adjusting an amplitude of the high-frequency voltage command so that the high-frequency current amplitude command matches an amplitude of the high-frequency current, thereby obtaining a high-frequency voltage amplitude at the third magnetic pole position;

calculating a gain based on the rotating machine constant of each phase based on the high-frequency voltage amplitude at each magnetic pole position acquired in the first step, the second step, and the third step;

giving the calculated gain based on the constant of the rotating machine of each phase, and adjusting the imbalance of the high-frequency current between the phases of the rotating machine; and

and calculating an estimated position of a magnetic pole of a rotor of the rotary machine using the adjusted high-frequency current, and driving the rotary machine based on the estimated position of the magnetic pole.

8. The control method of an alternating-current rotary machine according to claim 6,

in the step of adjusting the imbalance of the high-frequency current between the phases of the rotating machine, the imbalance of the high-frequency current between the phases is adjusted by applying a gain calculated based on the average value of the high-frequency current amplitudes of the phases acquired in the first step, the second step, and the third step.

9. The control method of an alternating-current rotary machine according to claim 7,

in the step of adjusting the imbalance of the high-frequency current between the phases of the rotating machine, the imbalance of the high-frequency current between the phases is adjusted by applying a gain calculated based on the average value of the high-frequency voltage amplitudes of the phases acquired in the first step, the second step, and the third step.

Technical Field

The present application relates to a control device for an ac rotary machine and a control method for an ac rotary machine.

Background

As a method for detecting the rotor position of an ac rotary machine without using a position sensor, there is known a method for detecting the position of the rotary machine by applying a high-frequency voltage for detecting the rotor phase in addition to a voltage for controlling the rotation of the ac rotary machine (for example, patent document 1). In this method, the magnetic pole position of the rotary machine is detected using the salient polarity of the inductance in which the inductance of the rotary machine changes in a sinusoidal shape with a 2-fold cycle with respect to one cycle of the rotor.

Patent document 1 discloses that a high-frequency current of each phase is extracted from a current of each phase detected by a current sensor using a high-pass filter or the like, and a three-phase high-frequency power command for matching a three-phase high-frequency current with a high-frequency target current is output. Then, the magnetic pole position is calculated from the space vector of the three-phase high-frequency power command.

Patent document 1: japanese patent No. 3882728

Disclosure of Invention

In patent document 1, the current of each phase is detected by a current sensor in order to calculate the magnetic pole position, but if manufacturing variations of the rotary machine occur, the variations of the inductance of each phase become large due to manufacturing errors, and the inductance cannot have ideal sinusoidal characteristics. Therefore, the detection accuracy of the final magnetic pole position is lowered, and the positioning accuracy in the position control of the rotary machine is lowered.

The present application discloses a technique for solving the above-described problem, and an object of the present application is to obtain a control device for an ac motor, which improves detection accuracy of a magnetic pole position in position control.

The control device for an AC rotating machine disclosed in the present application comprises: a control unit that generates a fundamental wave voltage command for driving a rotary machine, generates a high-frequency voltage command for estimating a magnetic pole position of a rotor of the rotary machine, and calculates a voltage command using the fundamental wave voltage command and the high-frequency voltage command; a voltage applying unit that applies a voltage to the rotary machine based on the voltage command; a current detection unit that detects a current of each phase of the rotary machine; magnetic pole position calculation means for extracting high-frequency currents of respective phases from the detected currents of the rotating machine and calculating estimated positions of the magnetic pole positions; and an imbalance adjuster that gives a gain based on a rotor constant of each phase to adjust imbalance of the high-frequency current between the phases, wherein the magnetic pole position calculation unit calculates the estimated position of the magnetic pole of the rotor of the rotating machine using the high-frequency current with the imbalance adjusted.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the control device of the ac rotating machine disclosed in the present application, the current imbalance is corrected by applying a gain for correcting the imbalance to the three-phase current detection values. This can improve the position estimation accuracy and the positioning accuracy.

Drawings

Fig. 1 is a block diagram showing a configuration of a control device of a rotary machine according to embodiment 1.

Fig. 2 is a block diagram showing a configuration of a control unit according to embodiment 1.

Fig. 3 is a block diagram showing the configuration of the magnetic pole position calculating means according to embodiment 1.

Fig. 4 is a block diagram showing the configuration of the high-frequency component extraction unit according to embodiment 1.

Fig. 5 is a diagram illustrating a rotor magnetic flux vector according to embodiment 1.

Fig. 6 is a block diagram illustrating a magnetic pole position calculator according to embodiment 1.

Fig. 7 is a diagram showing a comparative example for explaining the difference (position error) between the actual magnetic pole position and the position command according to embodiment 1.

Fig. 8 is a diagram for explaining a position error in the case where the sensorless position control is performed using the imbalance correction of the high-frequency current according to embodiment 1.

Fig. 9 is a block diagram showing a hardware configuration of a rotary machine system including a control device of a rotary machine according to embodiment 1.

Fig. 10 is a block diagram showing a configuration of a control unit according to embodiment 2.

Fig. 11 is a block diagram illustrating a filter coefficient acquisition flow according to embodiment 3, and is a block diagram in a case where the configuration of embodiment 1 is adopted.

Fig. 12 is a block diagram illustrating a filter coefficient acquisition flow according to embodiment 3, and is a block diagram in a case where the configuration of embodiment 2 is adopted.

Detailed Description

Hereinafter, embodiments will be described with reference to the drawings. In the drawings, the same reference numerals denote the same or equivalent parts.

Embodiment 1.

A control device of a rotary machine according to embodiment 1 will be described with reference to the drawings. Fig. 1 is a diagram showing a configuration of a control device of a rotary machine according to embodiment 1. The operation of each component will be described in detail below based on the configuration diagram.

The rotary machine 1 is a synchronous machine that is an ac rotary machine, and in the present embodiment, is a synchronous machine using a permanent magnet. In the present embodiment, a description is given of a configuration in which a synchronous machine using a permanent magnet is taken as an example of the rotary machine, but a synchronous machine such as a reluctance motor may be used. With the same configuration as in the present embodiment, the imbalance of the high-frequency current can be corrected by using the imbalance adjuster 62 or the like described later.

The control device 10 includes: a current detection means 2 connected to the rotary machine 1 and detecting a rotary machine current (a three-phase current vector) flowing through the rotary machine 1; a voltage applying unit 3 configured by a power converter such as an inverter circuit, for applying a voltage to the rotary machine 1 based on a voltage command output from the control unit 5; a magnetic pole position calculation unit 6 that calculates a magnetic pole position using the detected current vector detected by the current detection unit 2; and a coordinate converter 4 for performing coordinate conversion using the estimated position of the magnetic pole position calculated by the magnetic pole position calculation unit 6 on the detected current vector detected by the current detection unit 2, and outputting the converted current vector to the control unit 5.

Hereinafter, each component of the control device 10 will be described in detail.

The current detection unit 2 detects three-phase detection current vectors (Iu, Iv, Iw) of the rotary machine 1.

The coordinate converter 4 coordinate-converts the three-phase detected current vector (Iu, Iv, Iw) detected by the current detection unit 2 into a current on the dq axis using the estimated position output from the magnetic pole position calculation unit 6 described later, and outputs the current as a detected current vector (Ids, Iqs). The dq axis is obtained by converting the stationary coordinate of the three-phase (UVW) axis into an orthogonal coordinate that rotates in synchronization with the rotor of the rotating machine, and is known.

In addition, the three-phase detected current vector may be calculated by detecting two phases and using the fact that the sum of the three-phase currents is zero, in addition to detecting the currents at all three phases. The three-phase detected current vector may be obtained by calculating the three-phase detected current vector based on the bus current of the inverter, which is the voltage applying means 3, the current flowing through the switching elements constituting the inverter, the states of the switching elements, and the like.

Fig. 2 is a diagram showing the configuration of the control unit 5. In fig. 2, the control unit 5 has a current controller 51, a high-frequency voltage command generator 52, a coordinate converter 53, an adder 54, and an adder-subtractor 55.

The adder-subtractor 55 subtracts the detected current vector (Ids, Iqs) from the current command vector (Id, Iq) to calculate and output a current deviation.

The current controller 51 outputs a fundamental wave voltage command vector (Vdf, Vqf) by PI control so that the current deviation input from the adder-subtractor 55 becomes 0. The fundamental wave voltage command vector is a drive command for the rotational operation of the synchronous machine.

The high-frequency voltage command generator 52 generates d-axis and q-axis high-frequency voltage command vectors (Vdh, Vqh). The frequency of the high-frequency voltage command vector is higher than the frequency of the fundamental wave voltage command vector.

The adder 54 outputs a voltage command (Vd ×, Vq ×) obtained by adding the fundamental wave voltage command vector (Vdf, Vqf) and the high frequency voltage command vector (Vdh, Vqh).

The coordinate converter 53 converts the output of the adder 54, that is, (Vd ×, Vq ×) from the dq axis into the voltage command vector (Vu, Vv, Vw) of the stationary coordinate by using the estimated position output from the magnetic pole position computing unit 6, and outputs the converted voltage command vector.

Next, the operation of the magnetic pole position calculating means 6 will be described.

Fig. 3 is a diagram showing the structure of the magnetic pole position calculating means 6. In fig. 3, the magnetic pole position calculating means 6 includes a high frequency component extracting unit 61, an imbalance adjuster 62, and a magnetic pole position calculator 63.

The three-phase detected current vectors (Iu, Iv, Iw) detected by the current detection means 2 are input to the high-frequency component extraction unit 61, high-frequency components of the respective phases are extracted, and the high-frequency current vectors (Iuh, Ivh, Iwh) of the respective phases are output.

The imbalance adjuster 62 has filters 621, 622, and 623 corresponding to the phases, and corrects the current imbalance of the high-frequency current vectors (Iuh, Ivh, Iwh) of the phases.

The magnetic pole position calculator 63 calculates the estimated position of the magnetic pole position using the corrected high-frequency current vector.

The imbalance of the high-frequency currents of the phases is caused by a difference in inductance value between the UVW phases due to a manufacturing error of the rotary machine. Without this difference, the d-axis inductance Ld and the q-axis inductance Lq converted to the dq axis have constant values regardless of the rotor position. However, when this difference is large, the d-axis inductance Ld and the q-axis inductance Lq are each deformed into a sinusoidal wave having a 2-fold period with respect to one period of the rotor. This reduces the position estimation accuracy. Therefore, as described in the present embodiment, by providing a filter for correcting the imbalance with respect to the high-frequency current of each phase, it is possible to prevent the position estimation accuracy from being degraded.

Fig. 4 shows a control block diagram of the high-frequency component extraction section 61. The high-frequency component extraction unit 61 extracts the high-frequency current vector (Iuh, Ivh, Iwh) from the detected current vector (Iu, Iv, Iw) using the filter 611. As the filter 611, any filter may be used as long as it can extract the same frequency component as the high-frequency voltage vector from the detected current vector. For example, a known notch filter may be used as a narrow-band rejection filter to extract a high-frequency current vector.

The operation of the high-frequency component extracting unit 61 will be described with reference to an example in which a notch filter is used as the filter 611 in fig. 4. The notch filter (filter 611) is expressed by the following expression (1), and removes the angular frequency ω h of the high-frequency voltage vector. A notch filter (filter 611) is applied to the detected current vector (Iu, Iv, Iw) input to the high-frequency component extraction unit 61 to remove the angular frequency ω h component. In the adder-subtractor 612, the output of the filter 611 is subtracted from the detected current vector (Iu, Iv, Iw), thereby calculating a high-frequency current vector (Iuh, Ivh, Iwh) of the angular frequency ω h component from the detected current vector (Iu, Iv, Iw). In equation (1), s is the laplacian operator, and qx is the depth of the notch.

[ formula 1 ]

The high-frequency voltage command vector generated by the high-frequency voltage command generator 52 described with reference to fig. 2 can be expressed as a high-frequency rotating voltage vector as shown in equation (2).

[ formula 2 ]

In the above equation (2), the high-frequency rotation voltage vector is used, but in the equation (2), Vqh may be 0 in the equation (2-1), and a voltage vector alternating only in the d-axis direction may be used. In embodiment 1, a voltage vector that alternates only in the d-axis direction is used in the high-frequency voltage command generator 52.

As described above, the high-frequency current of each phase of UVW becomes unbalanced due to fluctuation of inductance value of each phase of UVW caused by manufacturing fluctuation or the like. Therefore, the high-frequency currents of the UVW phases of the high-frequency current vectors (Iuh, Ivh, Iwh) extracted by the high-frequency component extraction unit 61 become unbalanced. The filters 621, 622, and 623 included in the imbalance adjuster 62 shown in fig. 3 correct the difference in the high-frequency current between the UVW phases with respect to the high-frequency current vector (Iuh, Ivh, Iwh) extracted by the high-frequency component extraction unit 61.

Next, the values Gu, 622 of the filter 621, Gv, 623, and Gw will be described.

First, the high-frequency current amplitude of each phase when a voltage vector alternating only in the d-axis direction is applied in a state where the phases of the rotor N-pole and the UVW phase of the rotary machine 1 are aligned can be expressed as shown in formula (3). In the following expression, the superscript letters indicate values measured in a state where the phase of the N-pole of the rotor coincides with the direction of each phase.

[ formula 3 ]

Wherein the content of the first and second substances,

R^u、R^v、R^wis a resistance value when the phase of the rotor N pole of the rotary machine is matched with each phase of the UVW phase,

is an inductance when the phase of the rotor N pole of the rotary machine is matched with each phase of the UVW phase,

s: the laplacian operator.

Here, the inductance in the dq coordinate system is considered, but the filter may be configured using the inductance in the three-phase stationary coordinate system.

The high-frequency current amplitude of each phase represented by the formula (3) is used, and the ratio thereof to a certain reference current amplitude is taken, and the reciprocal thereof is a correction gain for each phase, and is set as a value to be given to a filter of each phase. Here, equation (4) represents the value Gu of the filter 621 in the case where the U-phase high-frequency current amplitude among the detected high-frequency current amplitudes of the rotary machine is set as a reference, equation (5) represents the value Gv of the filter 622 in this case, and equation (6) represents the value Gw of the filter 623 in this case.

[ formula 4 ]

[ FORMULA 5 ]

[ formula 6 ]

In addition, when the angular velocity of the high-frequency voltage command vector generated by the high-frequency voltage command generator 52 is sufficiently large and R < sL is satisfied, the influence of the stator resistance of the rotary machine can be ignored. Equation (7) represents the value Gu of the filter 621 in this case, equation (8) represents the value Gv of the filter 622 in this case, and equation (9) represents the value Gw of the filter 623 in this case. Here, the values of the filters 621, 622, and 623 are proportionality constants, and a filter applied to a high-frequency current that is a reference phase is expressed by 1 time with respect to a certain phase, whereby a configuration that suppresses the amount of calculation by a computer can be realized. The filter applied to the high-frequency current serving as the reference phase may be omitted.

[ formula 7 ]

[ formula 8 ]

[ formula 9 ]

The value set for the filters 621, 622, and 623 may be any of expression (4), expression (5), expression (6), expression (7), expression (8), and expression (9). The values obtained by applying the filters 621, 622, 623 to the high-frequency current vectors (Iuh, Ivh, Iwh), respectively, i.e., the values obtained by multiplying the correction gains are high-frequency correction current vectors (Iuh _ flt, Ivh _ flt, Iwh _ flt).

Next, the magnetic pole position calculator 63 will be explained. The magnetic pole position calculator 63 calculates the estimated magnetic pole position θ 0 of the rotary machine 1 based on the corrected high-frequency current vectors and the rotary machine constants (the stator resistance R, the stator inductance L, and the like) stored in advance.

First, a method of calculating the estimated magnetic pole position θ 0 of the rotary machine 1 will be described. Fig. 5 is a diagram showing the directions of application of the rotor magnetic flux and the voltage command vector according to embodiment 1. In fig. 5, the direction of the magnetic flux vector of the rotor is represented by dm axis, the direction orthogonal thereto is represented by qm axis, the direction indicated by the estimated magnetic pole position θ 0 obtained by applying the high-frequency alternating voltage vector is represented by d axis, the direction orthogonal thereto is represented by q axis, and it is assumed that there is a deviation Δ θ between the d axis and the dm axis.

The calculation of Δ θ, which is the deviation between the direction of the rotor magnetic flux vector (dm axis) and the direction (d axis) indicated by the estimated magnetic pole position θ 0, based on the high-frequency current obtained by applying the high-frequency voltage, may be performed, for example, by using the following formula (10) according to the method described in japanese patent No. 6104021. However, in the present embodiment, instead of the "q-axis high-frequency current amplitude" of the known document, the "high-frequency q-axis correction current amplitude" is calculated using the high-frequency correction current amplitude corrected by the imbalance adjuster 62, and Δ θ is calculated using the "high-frequency q-axis correction current amplitude".

[ formula 10 ]

Wherein the content of the first and second substances,

L_dis the inductance in the dm-axis direction,

L_qis the inductance in the direction of the qm axis,

|I_{qh_flt}and | is the q-axis high frequency correction current amplitude.

In equation (10), since the angular frequency ω h and the high-frequency voltage amplitude Vh of the high-frequency voltage can be arbitrarily set by the high-frequency voltage command generator 52, it is known that L and L can be obtained by Ld and Lq, which can be obtained by measurement in advance, and are known. Since integrator 634 described later operates stably so that Δ θ approaches zero, 2 Δ θ ≈ 0 can be approximated to sin2 Δ θ ≈ 2 Δ θ. Therefore, the following expression (11) is derived from the expression (10).

[ formula 11 ]

Fig. 6 is a diagram showing the structure of the magnetic pole position calculator 63. In the figure, the magnetic pole position calculator 63 includes a coordinate converter 631, an alternating current amplitude extraction unit 632, a magnetic pole deviation calculator 633, and an integrator 634.

First, the coordinate converter 631 coordinate-converts the high-frequency correction current vector (Iuh _ flt, Ivh _ flt, Iwh _ flt), which is the output of the imbalance adjuster 62, into a dq-axis current using the estimated position output from the magnetic pole position computing unit 6, and outputs the dq-axis current as a high-frequency correction current vector (Idh _ flt, Iqh _ flt).

Next, the alternating current amplitude extraction unit 632 calculates the amplitude | Iqh _ flt | from the q-axis component Iqh _ flt of the high-frequency correction current vector (Idh _ flt, Iqh _ flt) input from the coordinate converter 631 using the following expression (12). T in equation (12) is the period of Iqh _ flt.

[ formula 12 ]

The magnetic pole deviation calculator 633 calculates the deviation Δ θ by using either equation (10) or equation (11) using the amplitude | Iqh _ flt | extracted by the alternating current amplitude extraction unit 632.

The calculated deviation Δ θ is integrated by the integrator 634, and the estimated magnetic pole position θ 0 is calculated.

Further, although the configuration shown in embodiment 1 is only the configuration of the current control system, when the speed control system is constructed, the estimated speed ω can be calculated by differentiating the estimated magnetic pole position θ 0, and the speed control system can be constructed by adding the PI controller.

Fig. 7 and 8 are diagrams showing a difference (position error) between an actual magnetic pole position and a position command when the rotary machine is rotated by 1 rotation in the case where the position control operation is performed on the ac rotary machine without a sensor. Fig. 7 shows an example in which the configuration of the present embodiment is not used, and fig. 8 shows a position error when the rotating machine is operated by sensorless position control by correcting the imbalance of the high-frequency currents between the phases according to embodiment 1.

Fig. 8 shows the result of embodiment 1 in which the imbalance of the currents of the respective phases is reduced by about 5% by correcting the imbalance of the high-frequency currents of the respective phases, but it is understood that the error in positioning is reduced from 2 to 0.2[ deg ] and by about 90% as compared with fig. 7.

As described above, according to embodiment 1, the magnetic pole position calculating means 6 applies a gain for correcting the imbalance of the high-frequency current between the phases using the amplitude of the high-frequency current of each phase, thereby reducing the current imbalance between the phases and improving the detection accuracy of the magnetic pole position of the rotating machine. Further, by controlling the ac rotary machine based on the estimated position of the magnetic pole thus obtained, it is possible to improve the positioning accuracy even in the position control operation of the rotary machine without using a position sensor.

Fig. 9 shows a hardware configuration of a rotary machine system including the control device 10 of the ac rotary machine 1 according to embodiment 1.

As shown in fig. 9, the rotary machine system includes the rotary machine 1, a control device 10 of the rotary machine 1, and a higher-level controller 13 that provides a command to the control device 10, and drives the rotary machine 1. The control device 10 has a processor 11, a storage device 12, a current detection unit 2, and a voltage application unit 3 as a hardware configuration.

The control unit 5, the coordinate converter 4, and the magnetic pole position calculation unit 6 shown in fig. 1 are realized by a processor 11 executing a program stored in a storage device 12.

Although not shown, the storage device 12 includes a volatile storage device such as a random access memory and a nonvolatile auxiliary storage device such as a flash memory. Instead of the nonvolatile auxiliary storage device, an auxiliary storage device such as a hard disk may be provided.

A program is input to the processor 11 from an auxiliary storage device of the storage device 12 via a volatile storage device, and the processor 11 executes the program input from the storage device 12. The processor 11 outputs data such as the operation result to the volatile storage device of the storage device 12 or outputs the data to the auxiliary storage device via the volatile storage device, and stores the data.

The control unit 5, the coordinate converter 4, and the magnetic pole position calculation unit 6 may be realized by a processing circuit such as a system LSI.

The functions of the coordinate converter 4 and the voltage commands Vd, Vq to the voltage application means 3 to convert the three-phase voltage commands may be realized by the processor 11 or a processing circuit such as a system LSI. Further, the plurality of processors 11 and the plurality of storage devices 12 may cooperate to execute the above-described functions, or the plurality of processing circuits may cooperate to execute the above-described functions. Further, the above functions may be performed by combining them.

Embodiment 2.

In embodiment 1, a method is described in which the magnetic pole position calculating means 6 directly corrects the current imbalance by applying a gain to the high-frequency current (providing a filter). In embodiment 2, a method of correcting the imbalance of the high-frequency current vector (Iuh, Ivh, Iwh) by applying a correction filter to the high-frequency voltage command vector superimposed by the control unit 5 without correcting the detected current will be described. In the configuration diagram of the control device of the rotary machine shown in fig. 1 of embodiment 1, the control unit 5 has the configuration shown in fig. 10. The other structures are the same as those of the embodiment, and the description thereof is omitted.

Fig. 10 is a block diagram showing a configuration of a control unit 5 in the control device for a rotary machine according to embodiment 2. In the figure, the control unit 5 has a current controller 51, a high-frequency voltage command generator 52, a coordinate transformer 53, an unbalance adjuster 56, an adder-subtractor 55, and adders 57, 58, and 59. The high-frequency voltage command generator 52 has a coordinate converter 522, and the imbalance adjuster 56 has filters 561, 562, and 563.

The coordinate converter 522 converts the high-frequency voltage command vector (Vdh, Vqh) from the dq axis to a high-frequency voltage command vector (Vuh, Vvh, Vwh) of the stationary coordinate and outputs the vector.

The high-frequency voltage command vector (Vuh, Vvh, Vwh) input to the imbalance adjuster 56 is subjected to imbalance correction, and converted into a high-frequency correction voltage command vector (Vuh _ flt, Vvh _ flt, Vwh _ flt).

On the other hand, the adder-subtractor 55 subtracts the detected current vector (Ids, Iqs) from the current command vector (Id, Iq) to calculate and output a current deviation.

The current controller 51 outputs a fundamental wave voltage command vector (Vdf, Vqf) by PI control so that the current deviation input from the adder-subtractor 55 becomes 0.

The coordinate converter 53 converts the fundamental wave voltage command vector (Vdf, Vqf) that is the output of the current controller 51 from the dq axis to the fundamental wave voltage command vector (Vuf, Vvf, Vwf) of the stationary coordinate using the estimated position output from the magnetic pole position arithmetic unit 6, and outputs the converted vector.

The adders 57, 58, and 59 add the fundamental wave voltage command vectors (Vuf, Vvf, Vwf), and add the high-frequency correction voltage command vectors (Vuh _ flt, Vvh _ flt, Vwh _ flt), which are outputs of the imbalance adjuster 56, to output the voltage command vectors of the respective phases of the stationary coordinates whose high-frequency components have been corrected.

Referring to fig. 1, as described above, voltage is applied from the voltage applying means 3 to the rotary machine 1 based on the voltage command vector of each phase of the stationary coordinate with the high-frequency component corrected, which is output from the control means 5, and the current of each phase of UVW is detected by the current detecting means 2. At this time, the high frequency components of the voltage command vectors of the respective phases are corrected in advance, and therefore, the imbalance of the currents of the respective phases is suppressed. As a result, the magnetic pole position can be calculated with high accuracy by the magnetic pole position calculating means.

Next, a correction process in the imbalance adjuster 56 will be described.

Due to imbalance generated between inductance values of the UVW phases, a difference (imbalance) is generated between the phases of the high-frequency current vector (Iuh, Ivh, Iwh). The filters 561, 562, and 563 of the imbalance adjuster 56 have a function of correcting the high-frequency voltage command vector (Vuh, Vvh, Vwh) so that the high-frequency current vector (Iuh, Ivh, Iwh) does not become unbalanced with respect to the voltage command vector output to the voltage applying unit 3.

Here, a case where the angular velocity of the high-frequency voltage command vector generated by the high-frequency voltage command generator 52 is sufficiently large and R < sL holds is considered. In this case, the stator winding resistance value can be ignored, but a filter including the stator winding phase resistance value can be configured in the same manner as in embodiment 1 in consideration of the influence thereof.

The values Gu, 562, Gv, 563, and Gw of the filter 561 will be explained.

First, in a state where the phase of the N-pole of the rotor of the rotary machine 1 is matched with each of the UVW phases, the high-frequency voltage amplitude of each phase when the high-frequency alternating voltage is applied can be expressed as shown in the following expression (13).

[ formula 13 ]

Wherein the content of the first and second substances,

the high-frequency voltage amplitude of each phase represented by equation (13) is used, and the ratio to the high-frequency voltage amplitude of a certain reference phase is obtained, and the reciprocal thereof is used as the gain to be given to each phase, and is used as the value of the filter. Note that the reference phase may be any phase, but here, equation (14) represents the value Gu of the filter 561 when the U-phase high-frequency voltage amplitude is taken as the reference, equation (15) represents the value Gv of the filter 562 in this case, and equation (16) represents the value Gw of the filter 563 in this case.

[ formula 14 ]

[ formula 15 ]

[ formula 16 ]

By applying the filters 561, 562, and 563 thus set, the high-frequency voltage command vectors (Vuh, Vvh, Vwh) are subjected to imbalance correction, and high-frequency corrected voltage command vectors (Vuh _ flt, Vvh _ flt, Vwh _ flt) are output. By outputting the voltage command vector in consideration of the high-frequency correction voltage command vector (Vuh _ flt, Vvh _ flt, Vwh _ flt) from the control unit 5, imbalance between phases of the high-frequency current vector (Iuh, Ivh, Iwh) is suppressed, and the accuracy of magnetic pole position detection is improved.

In the present embodiment, the filters 621, 622, and 623 of the imbalance adjuster 62 included in the magnetic pole position calculating unit 6 shown in fig. 3 in embodiment 1 may be multiplied by 1, respectively, and the imbalance adjuster 62 may not perform correction. However, in order to further improve the accuracy of the current imbalance adjustment, both the imbalance adjuster 56 and the imbalance adjuster 62 may be set.

As described above, according to embodiment 2, the control unit 5 corrects the imbalance between the phases generated in the high-frequency current vector by correcting the high-frequency voltage command using the high-frequency voltage amplitude of each phase, so that the current imbalance between the phases is reduced, and the detection accuracy of the magnetic pole position of the rotary machine is improved. Further, by controlling the ac rotary machine based on the estimated position of the magnetic pole thus obtained, it is possible to improve the positioning accuracy even in the position control operation of the rotary machine without using a position sensor.

Embodiment 3.

In embodiment 3, a flow of obtaining filter coefficients in the imbalance adjusters according to embodiments 1 and 2 will be described.

Fig. 11 is a flowchart showing an acquisition flow in the case where coefficients are set to the filters 621, 622, and 623 of the imbalance adjuster 62 of the magnetic pole position calculating unit 6, which is the configuration of embodiment 1.

First, in step 801, the control unit 5 applies a dc current to the first magnetic pole position, i.e., the phase of the rotary machine 1, and rotates the N pole of the rotor to the first magnetic pole position. After the turning operation is completed, the control means 5 applies a high-frequency alternating voltage or a high-frequency rotating voltage to the rotary machine 1, and the current detection means 2 measures the amplitude of the high-frequency current.

In step 802, the control unit 5 applies a dc current to the second magnetic pole position, i.e., the phase of the rotary machine 1, and rotates the N pole of the rotor to the second magnetic pole position. After the turning operation is completed, the control means 5 applies a high-frequency alternating voltage or a high-frequency rotating voltage to the rotary machine 1, and the current detection means 2 measures the amplitude of the high-frequency current.

In step 803, the control unit 5 applies a dc current to the third magnetic pole position, i.e., the phase of the rotary machine 1, and rotates the N-pole of the rotor to the third magnetic pole position. After the turning operation is completed, the control means 5 applies a high-frequency alternating voltage or a high-frequency rotating voltage to the rotary machine 1, and the current detection means 2 measures the amplitude of the high-frequency current.

The operations in steps 801 to 803 differ only in the magnetic pole position, and are the same operations. The first magnetic pole position, the second magnetic pole position, and the third magnetic pole position are positions of a phase in any of the UVW phases, and the measurement may be performed in different order.

Further, the high-frequency current amplitude is measured sequentially from the first magnetic pole position determined in advance, but the rotor position of the rotary machine at the time point when the acquisition flow of fig. 11 is operated may be measured and the phase at the nearest measurement point may be started. For example, when the initial rotor position at the start of the flow is close to the V phase, the acquisition flow may be executed from the measurement point closest to the current rotor position, such as starting measurement from the V phase.

In the next step 804, the equations (7), (8), and (9) are calculated using the high-frequency current amplitudes obtained in steps 801 to 803. After the calculation is completed, the values are set to the filters 621, 622, and 623 included in the imbalance adjuster 62.

Next, an acquisition flow in the case where coefficients are set to the filters 561, 562, and 563 of the imbalance adjuster 56 of the control unit 5, which is the configuration of embodiment 2, will be described with reference to fig. 12.

However, in the process of obtaining the coefficients of the filters 561, 562, 563 of the imbalance adjuster 56, the control unit 5 uses the control configuration shown in fig. 2. In this case, the high-frequency voltage command generator 52 includes an adder-subtractor that subtracts the high-frequency current amplitude vector (| Idh |, 0) calculated based on the high-frequency current vector (Idh, 0) detected from the high-frequency current amplitude command vector (| Idh |, 0), and calculates and outputs the amplitude deviation, and a controller. The controller controls the amplitude deviation input from the adder-subtractor to be 0, calculates the high-frequency voltage amplitude Vh, and outputs a high-frequency voltage vector (Vdh, 0). The high-frequency current amplitude command may be set to any value, and may be set to, for example, 5% of the rated current of the rotary machine in advance.

Fig. 12 is a flowchart showing a flow of obtaining the coefficients of the filters of the imbalance adjuster 56 of the control unit 5.

First, in step 901, the control unit 5 applies a dc current to the first magnetic pole position, i.e., the phase of the rotary machine 1, and rotates the N pole of the rotor to the first magnetic pole position. After the end of the turning operation, the control unit 5 generates a high-frequency voltage amplitude such that the high-frequency current amplitude matches the high-frequency current amplitude command, and acquires the high-frequency voltage amplitude at the first magnetic pole position. The high-frequency voltage amplitude may be calculated in the same manner as when the amplitude | Iqh _ flt | is extracted from the q-axis component Iqh _ flt using equation (12).

In step 902, the control unit 5 applies a dc current to the second magnetic pole position, i.e., the phase of the rotary machine 1, and rotates the N pole of the rotor to the second magnetic pole position. After the end of the turning operation, the control unit 5 generates the amplitude of the high-frequency voltage such that the amplitude of the high-frequency current coincides with the high-frequency current command, and acquires the amplitude of the high-frequency voltage at the second magnetic pole position.

In step 903, the control unit 5 applies a dc current to the third magnetic pole position, i.e., the phase of the rotary machine 1, and rotates the N-pole of the rotor to the third magnetic pole position. After the end of the turning operation, the control unit 5 generates the amplitude of the high-frequency voltage such that the amplitude of the high-frequency current coincides with the high-frequency current command, and acquires the amplitude of the high-frequency voltage at the third magnetic pole position.

The operations in steps 901 to 903 are the same operations with different magnetic pole positions. The first magnetic pole position, the second magnetic pole position, and the third magnetic pole position are positions of phases of any of the UVW phases, and the high-frequency voltage amplitude may be obtained in different order.

Further, the high-frequency current amplitude is sequentially acquired from the first magnetic pole position determined in advance, but the rotor position of the rotary machine at the time point when the acquisition flow of fig. 12 is operated may be measured and started from the phase at the nearest measurement point. For example, when the initial rotor position at the start of the flow is close to the W phase, the acquisition flow may be executed from the measurement point closest to the current rotor position, such as starting from the W phase.

In the next step 904, the equations (14), (15) and (16) are calculated using the high-frequency voltage amplitudes obtained in steps 901 to 903. After the calculation is completed, the values are set to the filters 561, 562, and 563 included in the imbalance adjuster 56.

In fig. 11 and 12, the filter is configured such that the filter value is set by measuring the high-frequency current amplitude and the high-frequency voltage amplitude of each phase, respectively, but the filter may be configured by measuring the stator resistance value R and the stator inductance L at 3 magnetic pole positions, respectively.

First, measurement of the stator resistance R will be described, and here, measurement of the stator resistance Ru of the U-phase will be described.

The phase of the N-pole of the rotor of the rotary machine 1 is matched with U, and a dc voltage command is given, and at this time, the current flowing through the rotary machine is measured and calculated using the following equation (17).

[ formula 17 ]

Wherein the content of the first and second substances,

d-axis voltage finger when the N pole of the rotor of the rotary machine is matched with UIn order to ensure that the water-soluble organic acid,

is a d-axis current when the N pole of the rotor of the rotary machine is matched with the U pole,

the phase of the N-pole of the rotor of the rotary machine 1 can be rotated for the other phases, and the measurement can be performed in the same manner.

Next, measurement of the stator inductance L will be described, and here, a case where the inductance when the N pole of the rotor is aligned with the U pole is measured will be described.

A phase of an N pole of a rotor of a rotary machine 1 is made to coincide with U, and a high-frequency voltage is applied so that R < sL is satisfied. The high-frequency current amplitude at this time is obtained, and the inductance when the N-pole of the rotor is matched with the U-pole is calculated using the following expression (18) derived from the above expression (3).

[ formula 18 ]

Wherein the content of the first and second substances,

is an inductance when the N pole of the rotor of the rotary machine is consistent with the U pole,

the phase of the N-pole of the rotor of the rotary machine 1 can be rotated for the other phases, and the measurement can be performed in the same manner.

As described above, according to embodiment 3, the high-frequency current amplitude or the high-frequency voltage amplitude for 3 magnetic pole positions of the rotary machine is acquired, and the gain for correction for each phase is calculated. By using the obtained gain as a value of a filter and correcting the imbalance of the high-frequency current, the current imbalance is suppressed, and the detection accuracy of the magnetic pole position of the rotary machine is improved. Further, by controlling the ac rotary machine based on the estimated position of the magnetic pole thus obtained, it is possible to improve the positioning accuracy even in the position control operation of the rotary machine without using a position sensor.

Embodiment 4.

In embodiments 1 to 3 described above, the correction gain, which is a value set to each filter, is calculated based on the amplitude of the high-frequency current or the amplitude of the high-frequency voltage of a certain reference phase, and the filters are configured to correct the inter-phase imbalance of the high-frequency current. However, depending on the detection accuracy of the amplitude of the high-frequency current or high-frequency voltage of the reference phase, the inter-phase imbalance may not be sufficiently eliminated.

Therefore, in embodiment 4, the calculation method of the reference phase uses the average value of the high-frequency current amplitude or the high-frequency voltage amplitude of each phase, thereby achieving further improvement in accuracy by the correction.

First, a case of setting the filter value of the imbalance adjuster 62 included in the magnetic pole position calculation unit 6 in embodiment 1 will be described. The obtained average value | Iave | of the high-frequency current amplitude of the rotary machine is calculated using the following expression (19).

[ formula 19 ]

Wherein the content of the first and second substances,

is the d-axis high-frequency current amplitude when the rotor N pole of the rotating machine is consistent with the UVW phase,

the high-frequency current amplitude of each phase may be calculated using equation (12) in the same manner as when the amplitude | Iqh _ flt | is extracted from the q-axis component Iqh _ flt.

When the amplitude of the current serving as the reference is the average value | Iave | of the amplitude of the high-frequency current, equations (4), (5), and (6) can be rewritten as follows, equation (20) represents the value Gu of the filter 621 of the imbalance adjuster 62, equation (21) represents the value Gv of the filter 622, and equation (22) represents the value Gw of the filter 623.

[ FORMULA 20 ]

[ FORM 21 ]

[ FORMULA 22 ]

Next, a case of setting the filter value of the imbalance adjuster 56 included in the control unit 5 in embodiment 2 will be described. The average value | Vave | of the measured high-frequency voltage amplitude of the rotary machine is calculated using the following expression (23).

[ TYPE 23 ]

Wherein the content of the first and second substances,

the d-axis high-frequency voltage amplitude is obtained when the rotor N-pole of the rotary machine and the UVW phase are matched with each other.

When the amplitude of the voltage serving as a reference is the average value | Vave | of the amplitude of the high-frequency voltage, equations (14), (15), and (16) can be rewritten as follows, equation (24) represents the value Gu of the filter 561, equation (25) represents the value Gv of the filter 562, and equation (26) represents the value Gw of the filter 563.

[ FORMULA 24 ]

[ formula 25 ]

[ formula 26 ]

As described above, according to embodiment 4, the high-frequency current amplitude or the high-frequency voltage amplitude for 3 magnetic pole positions is acquired, the correction gain is calculated with the average value of the high-frequency current amplitude or the high-frequency voltage amplitude for 3 positions as a reference, and the filter value is set. This makes it possible to set the filter value without separately measuring the rotating machine constants such as the stator resistance R and the stator inductance L, and thus to improve the positioning accuracy. Further, as compared with the case where the filter value is set with the high-frequency current amplitude or the high-frequency voltage amplitude of any one of the 1 parts as a reference, it is possible to correct the imbalance of the high-frequency current of the rotating machine with high accuracy, thereby improving the positioning accuracy.

Embodiment 5.

In the above-described embodiment, in order to obtain the filter coefficient of each filter, it is necessary to measure the high-frequency current amplitude or the high-frequency voltage amplitude for 3 magnetic pole positions, and it is necessary to measure time. In embodiment 5, the measurement is facilitated by setting the measurement site for the magnetic pole position to 1 site.

Here, an example will be described in which, when the N-pole of the rotor of the rotary machine is aligned with the phase of the U-phase, the filter is configured with the U-phase current of the rotary machine detection current as a reference. The phase to be the reference may be any UVW phase.

When the N-pole of the rotor of the rotary machine 1 is aligned with the U-phase, the relationship between the V-phase and W-phase currents, i V-Iu/2 and i W-Iu/2, with respect to the U-phase current is established. Using this relationship, equations (4), (5), and (6) can be rewritten as follows, equation (27) represents the value Gu of the filter 621 of the imbalance adjuster 62, equation (28) represents the value Gv of the filter 622, and equation (29) represents the value Gw of the filter 623.

[ formula 27 ]

[ FORMULA 28 ]

[ formula 29 ]

Wherein the content of the first and second substances,

is the high frequency current amplitude of each phase.

The high-frequency current amplitude of each phase may be calculated using equation (12) in the same manner as when the amplitude | Iqh _ flt | is extracted from the q-axis component Iqh _ flt.

As described above, according to embodiment 5, the high-frequency current amplitude for 1 of the 3 magnetic pole positions is acquired, and the filter values of the 3 phases are set based on the acquired high-frequency current amplitude. This makes it possible to set the filter value without separately measuring the rotating machine constants such as the stator resistance R and the stator inductance L, and therefore, the imbalance correction of the high-frequency current becomes easy. This makes it possible to correct the current imbalance and improve the detection accuracy of the magnetic pole position of the rotary machine. Further, by controlling the ac rotary machine based on the estimated position of the magnetic pole thus obtained, it is possible to improve the positioning accuracy even in the position control operation of the rotary machine without using a position sensor.

Various exemplary embodiments and examples are described in the present application, but the various features, modes and functions described in 1 or more embodiments are not limited to the application to a specific embodiment, and can be applied to the embodiments alone or in various combinations.

Therefore, numerous modifications not illustrated can be conceived within the technical scope disclosed in the present application. For example, the case where at least 1 component is modified, added, or omitted, and the case where at least 1 component is extracted and combined with the components of other embodiments are included.

Description of the reference numerals

1: rotating machine, 2: current detection unit, 3: voltage applying unit, 4, 53, 522, 631: coordinate transformer, 5: control unit, 6: magnetic pole position arithmetic unit, 10: control device, 11: processor, 12: storage device, 13: controller, 51: current controller, 52: high-frequency voltage command generator, 55, 612: adder-subtractor, 54, 57, 58, 59: adder, 56, 62: imbalance adjuster, 61: high-frequency component extraction unit, 63: pole position operator, 561, 562, 563, 621, 622, 623: filter, 632: alternating current amplitude extraction unit, 633: magnetic pole deviation calculator, 611: filter, 634: integrator