Control device for rotating machine

Abstract

A control device (1A) for a rotating machine comprises: a current detector (4) that detects a stator current of a rotating machine (3); a position estimator (6A) that calculates an estimated rotor position of the rotating machine (3); a controller (5) that outputs a stator voltage command value on the basis of the stator current and the estimated rotor position; a voltage application unit (2) that applies a drive voltage to the rotating machine (3) on the basis of the stator voltage command value; a stationary coordinate interlinkage magnetic flux calculation unit (8) that calculates a first interlinkage magnetic flux calculation value by integrating a stator voltage on a stationary coordinate without converting to a value on a rotational coordinate synchronized with the rotational speed of the rotating machine (3), and a rotational coordinate interlinkage magnetic flux calculation unit (9) that calculates a second interlinkage magnetic flux calculation value by integrating the stator voltage converted to a value on the rotational coordinate synchronized with the rotational speed of the rotating machine (3) without using the first interlinkage magnetic flux calculation value. A position estimator (6A) calculates an estimated rotor position using at least one of the first interlinkage magnetic flux calculation value and the second interlinkage magnetic flux calculation value in accordance with the rotational speed.

Description

Rotating machine control device

[0001] The present disclosure relates to a control device for a rotating machine having magnetic salience, i.e., a rotating machine whose inductance changes depending on rotor position, that controls the rotating machine by obtaining rotor position information without using a position sensor that detects rotor position.

[0002] In order to drive a rotating machine while fully utilizing its performance, rotor position information is required. For this reason, conventional rotating machine control devices use position information detected by a position sensor attached to the rotating machine. However, from the perspectives of further reducing the manufacturing cost of rotating machines, reducing the size of rotating machines, and improving the reliability of rotating machines, technologies for driving rotating machines without a position sensor have been developed.

[0003] Position sensorless control of rotating machines includes a method of estimating rotor position by applying a high-frequency voltage to the rotating machine, and a method of estimating rotor position based on the induced voltage, flux linkage, etc. of the rotating machine without applying a high-frequency voltage. To estimate rotor position based on the flux linkage of a rotating machine, it is possible to extract the component that rotates in synchronization with the rotor flux from the calculated value of the flux linkage, or extract the component due to the inductance component that fluctuates in synchronization with the rotor position from the calculated value of the flux linkage.

[0004] Patent Document 1 listed below discloses a method for estimating the rotor position based on the flux linkage of a rotating machine obtained by integrating the stator voltage. However, the method of Patent Document 1 uses the stator voltage on the stationary coordinate system as it is, without converting the stator voltage into the rotating coordinate system synchronized with the rotational angular velocity of the rotating machine.

[0005] In a rotating machine, quantities such as voltage, current, and magnetic flux linkage are sinusoidal AC quantities in stationary coordinates. Therefore, as the frequency of these quantities increases, the number of sampling points per cycle decreases, making it impossible to accurately detect the waveforms of these quantities. Furthermore, as the number of sampling points per cycle decreases, the effect of sampling delay increases.

[0006] Japanese Patent Application Laid-Open No. 2018-183005

[0007] As described above, in the method of Patent Document 1, the stator voltage on the stationary coordinate system is integrated to obtain the flux linkage. Therefore, the method of Patent Document 1 has a problem in that accuracy and stability decrease in the high rotation speed region.

[0008] The present disclosure has been made in consideration of the above, and aims to provide a control device for a rotating machine that is capable of estimating rotor position stably and with high accuracy over a wide range of rotational speeds from low rotational speeds to high rotational speeds.

[0009] In order to solve the above-mentioned problems and achieve the object, a control device for a rotating machine according to the present disclosure includes a current detector, a position estimator, a controller, a voltage applicator, a stationary coordinate flux linkage calculator, and a rotating coordinate flux linkage calculator. The current detector detects a stator current flowing through a stator of the rotating machine. The position estimator calculates an estimated rotor position, which is an estimated value of the rotor position of the rotating machine. The controller outputs a stator voltage command value for driving the rotating machine based on the stator current and the estimated rotor position. The voltage applicator applies a drive voltage to the rotating machine based on the stator voltage command value. The stationary coordinate flux linkage calculator calculates a first calculated flux linkage value by integrating the stator voltage in the stationary coordinate without converting it into a value in the rotating coordinate synchronized with the rotational speed of the rotating machine. The rotating coordinate flux linkage calculator calculates a second calculated flux linkage value by integrating the stator voltage converted into a value in the rotating coordinate synchronized with the rotational speed of the rotating machine without using the first calculated flux linkage value. The position estimator calculates an estimated rotor position using at least one of the first and second flux linkage calculation values ​​according to the rotation speed.

[0010] The control device for a rotating machine according to the present disclosure has the advantage of being able to estimate the rotor position stably and with high accuracy over a wide range of rotational speeds from low rotational speeds to high rotational speeds.

[0011] FIG. 1 is a diagram showing an example of the configuration of a control device for a rotating machine according to embodiment 1. FIG. 2 is a diagram showing an example of the configuration of a position estimator according to embodiment 1. FIG. 3 is a diagram used to explain the operation of a weighted averager according to embodiment 1. FIG. 4 is a diagram showing an example of the configuration of a control device for a rotating machine according to embodiment 2. FIG. 5 is a diagram showing an example of the configuration of a position estimator according to embodiment 2. FIG. 6 is a diagram used to explain the operation of a weighted averager according to embodiment 2. FIG. 7 is a diagram showing a first example of the hardware configuration of a control device for a rotating machine according to embodiments 1 and 2. FIG. 8 is a diagram showing a second example of the hardware configuration of a control device for a rotating machine according to embodiments 1 and 2.

[0012] Hereinafter, a control device for a rotating machine according to an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. In this document, the angular velocity at which the rotating machine rotates will be referred to as the "rotational speed."

[0013] Embodiment 1. Fig. 1 is a diagram showing an example of the configuration of a control device for a rotating machine according to embodiment 1. The control device 1A for a rotating machine according to embodiment 1 is a control device that controls the operation of a rotating machine 3. As shown in Fig. 1, the control device 1A includes a voltage applicator 2, a current detector 4, a controller 5, a position estimator 6A, and a flux linkage calculator 7. The flux linkage calculator 7 also includes a stationary coordinate flux linkage calculator 8, which is a first flux linkage calculator, and a rotating coordinate flux linkage calculator 9, which is a second flux linkage calculator.

[0014] The current detector 4 is disposed between the voltage applicator 2 and the rotating machine 3, and detects the stator current i flowing through the stator 17 of the rotating machine 3. ｓｕ , i ｓｖ , i ｓｗ The voltage applicator 2 detects the stator voltage command value v output from the controller 5. ｓｕ ＊ , v ｓｖ ＊ , v ｓｗ ＊ Based on this, a drive voltage is applied to the rotating machine 3. Although not shown, the voltage applicator 2 includes a DC power supply, an inverter circuit, a PWM (Pulse Width Modulation) modulator, and the like. The inverter circuit converts the DC voltage output from the DC power supply into an AC voltage. The PWM modulator generates a PWM signal for driving the switching elements of the inverter circuit.

[0015] In the first embodiment, the rotating machine 3 is assumed to be a rotating machine having an inductance fluctuation component whose inductance varies depending on rotor position. An example of this type of rotating machine 3 is a synchronous reluctance motor that does not have a magnet in the rotor 18. In this paper, if the rotating machine 3 is a synchronous reluctance motor, the direction of the rotor 18 where the inductance is maximized is defined as the d-axis, and the direction of the rotor 18 where the inductance is minimized is defined as the q-axis, and the rotor position is defined as the d-axis of the rotor 18. In addition, in this paper, it is assumed that the inverter circuit and the rotating machine 3 both have a three-phase configuration. Note that even if the rotating machine 3 is an induction motor or a permanent magnet motor with a magnet in the rotor 18, the inductance may vary depending on rotor position. Therefore, the technology described in this paper can also be applied to induction motors, permanent magnet motors, and other motors whose inductance varies depending on rotor position.

[0016] The position estimator 6A estimates the rotor position of the rotating machine 3. Specifically, the position estimator 6A estimates the rotor position of the rotating machine 3. Specifically, the position estimator 6A estimates the rotor position of the rotating machine 3 based on the calculated flux linkage value Ψ calculated in the stationary coordinate by the stationary coordinate flux linkage calculator 8. ｓ１ αβ α-axis component Ψ ｓ１α and the β-axis component Ψ ｓ１β and the calculated value Ψ of the flux linkage calculated in the rotating coordinate system by the rotating coordinate flux linkage calculator 9. ｓ２ ｄｑ d-axis component Ψ ｓ２ｄ and the q-axis component Ψ ｓ２ｑ and the estimated rotor position θ ＾ ｒ and outputs the result to the controller 5.

[0017] The controller 5 calculates the stator current i ｓｕ , i ｓｖ , i ｓｗ and the estimated rotor position θ ＾ ｒ Based on this, the stator voltage command value v for driving the rotating machine 3 is calculated. ｓｕ ＊ , v ｓｖ ＊ , v ｓｗ ＊ and outputs it to the voltage applicator 2. Specifically, the controller 5 generates the stator current i ｓｕ , iｓｖ , i ｓｗ and estimated rotor position θ ＾ ｒ The rotating machine 3 is then driven to obtain the desired torque command value T ＊ The stator voltage command value v ｓｕ ＊ , v ｓｖ ＊ , v ｓｗ ＊ Generate.

[0018] Next, we will explain in more detail the operation of the controller 5. As shown in Fig. 1, the controller 5 includes a current command calculator 501, a three-phase to two-phase converter 502, a rotating coordinate converter 503, a current controller 504, a rotating coordinate inverse converter 505, and a two-phase to three-phase converter 506.

[0019] The current command calculator 501 calculates the torque command value T ＊ The current command value i on the rotating two-phase coordinate system required to generate an output corresponding to ｓｄ ＊ , i ｓｑ ＊ That is, the current command calculator 501 calculates the torque command value T ＊ The current command value i required to generate an output corresponding to ｓｄ ＊ , i ｓｑ ＊ is calculated on the rotating coordinate system that rotates in synchronization with the rotor position. ｓｄ ＊ , i ｓｑ ＊ is the value where the copper loss of the rotating machine 3 is minimum, that is, the stator current i ｓｕ , i ｓｖ , i ｓｗ The effective current value of the stator current i is selected to be the minimum. ｓｕ , i ｓｖ , i ｓｗ However, the current command value i on the rotating two-phase coordinate system is set so that the interlinkage magnetic flux is minimized or the efficiency of the voltage applicator 2 or the rotating machine 3 is maximized. ｓｄ ＊ , i ｓｑ ＊For ease of explanation, the "rotating two-phase coordinate system" will be simply referred to as the "rotating coordinate system" below.

[0020] The three-phase to two-phase converter 502 calculates the stator current i on the three-phase coordinate system as shown in the following equation (1). ｓｕ , i ｓｖ , i ｓｗ The rotating machine current i on the stationary two-phase coordinate system ｓα , i ｓβ Hereinafter, for the sake of simplicity, the "stationary two-phase coordinate system" will be simply referred to as the "stationary coordinate system." Note that the three-phase coordinate system is also a stationary coordinate system in which the coordinate axes do not rotate.

[0021]

[0022] In this paper, we use the transformation matrix C in the above equation (1) for three-phase to two-phase transformation. ３２ Use.

[0023] The rotation coordinate converter 503 converts the estimated rotor position θ calculated by the position estimator 6A into the ＾ ｒ Using the above, the rotating machine current i ｓα , i ｓβ The d-q axis current i on the rotating coordinate system ｓｄ , i ｓｑ Rotate the coordinate system to

[0024]

[0025] In this paper, we use the transformation matrix C in the above equation (2) for the rotational coordinate transformation. ｄｑ (θ ＾ ｒ ) is used.

[0026] The current controller 504 converts the dq axis current i ｓｄ , i ｓｑ is the current command value i ｓｄ ＊ , i ｓｑ ＊ The stator voltage command value v ｓｄ ＊ , v ｓｑ ＊For this current control, for example, proportional integral (PI) control or the like is used.

[0027] The rotating coordinate inverse converter 505 calculates the estimated rotor position θ as shown in the following equation (3): ＾ ｒ Using this, the stator voltage command value v on the rotating coordinate system is ｓｄ ＊ , v ｓｑ ＊ The stator voltage command value v on the stationary coordinate system ｓα ＊ , v ｓβ ＊ In this paper, the inverse rotational coordinate transformation is performed using the transformation matrix C ｄｑ －１ (θ ＾ ｒ ) is used.

[0028]

[0029] The two-phase to three-phase converter 506 calculates the stator voltage command value v on the stationary coordinate system as shown in the following equation (4). ｓα ＊ , v ｓβ ＊ The stator voltage command value v on the three-phase coordinate system ｓｕ ＊ , v ｓｖ ＊ , v ｓｗ ＊ Convert to.

[0030]

[0031] In this paper, we use the transformation matrix C in the above equation (4) for two-phase to three-phase transformation. ２３ Use.

[0032] Next, the position estimator 6A estimates the rotor position θ ＾ ｒ A method of calculating the above in the first embodiment will be described. First, the model of the rotating machine 3 is expressed in stationary coordinates by the following equations (5) and (6).

[0033]

[0034] "v" in the above formula (5) ｓαβ " is the stator voltage, and "i ｓ αβ " is the stator current. The superscript " αβ " indicates a value on the stationary coordinate system. Also, "R" in the above formula (5) ｓ " is the winding resistance, and "Ψ ｓ αβ " is the interlinkage magnetic flux in the rotating machine 3, and can be expressed by a matrix as in the above equation (6).

[0035] As mentioned above, the inductance of the rotating machine 3 changes depending on the rotor position. For this reason, the inductance of the rotating machine 3 is divided into two components: an average component and a fluctuating component. ｓａｖｇ " represents the average inductance component that does not change with the rotor position, and "L ｓｖａｒ " represents the inductance fluctuation component that changes at twice the frequency at which the rotor position changes. These inductance average components L ｓａｖｇ and inductance fluctuation component L ｓｖａｒ is the inductance L in the d-axis direction ｓｄ and the inductance L in the q-axis direction ｓｑ Using these, it is expressed by the following equations (7) and (8).

[0036]

[0037] In addition, the calculated value of the interlinkage magnetic flux Ψ in the above equation (6) ｓ αβ The estimated rotor position θ ＾ ｒ By performing a rotational coordinate transformation based on the above, the following equation (9) is obtained.

[0038]

[0039] In the above formula (9), the superscript " ｄｑ " indicates a value on the rotating coordinate system. Here, in the above equation (9), the inductance average component L ｓａｖｇ The component related to is described in the first term, and the inductance fluctuation component L ｓｖａｒ The relevant section is set out in paragraph 2.

[0040] In this paper, the inductance fluctuation component L ｓｖａｒ and the stator current i ｓ ｄｑ The component generated by this is called the "flux linkage inductance fluctuation." In this paper, the flux linkage inductance fluctuation is used to estimate the rotor position. In the case of a synchronous reluctance motor that does not have a magnet in the rotor 18, the rotor magnetic flux cannot be used to estimate the rotor position, so the flux linkage inductance fluctuation must be calculated accurately.

[0041] In this paper, we also use the estimated value of the flux linkage inductance fluctuation as "Ψ ＾ ｓｖａｒ ｄｑ " The estimated value of the flux linkage inductance fluctuation is expressed as Ψ ＾ ｓｖａｒ ｄｑ can be expressed by the following equation (10) from the second term of the above equation (9).

[0042]

[0043] Here, the estimated rotor position θ ＾ ｒ and the true value of the rotor position θ ｒ and are roughly equal, that is, θ ＾ ｒ ≒θ ｒ By approximating this, the above equation (10) can be simplified to the following equation (11).

[0044]

[0045] This estimated value Ψ of the flux linkage inductance fluctuation ＾ ｓｖａｒ ｄｑ If there is a reference calculation value, the estimated value Ψ ＾ ｓｖａｒ ｄｑ The rotor position can be estimated by comparing it with a reference calculated value.

[0046] Next, we will explain the method of calculating the flux linkage by the stationary coordinate flux linkage calculator 8. In this paper, the calculated value of the flux linkage calculated by the stationary coordinate flux linkage calculator 8 is called the "first flux linkage calculated value."

[0047] First, by transforming the above equation (5) which represents the model of the rotating machine 3 on the stationary coordinate system, the following equation (12) is obtained.

[0048]

[0049] As mentioned above, the flux linkage is one of the quantities of the rotating machine 3 on the stationary coordinate system, and is an AC quantity. Therefore, if the DC component in the initial value and in the steady state is set to zero, the stator voltage v ｓ αβ It can be calculated by integrating the components including (13) and (14). In this case, it is desirable to apply a high-pass filter to remove direct current components and low-frequency components. Specifically, the equation when a high-pass filter is applied and the integral equation can be expressed as the following equations (13) and (14).

[0050]

[0051] "ω" in the above equations (13) and (14) ｈｐｆ " is the cutoff angular frequency of the high-pass filter. "Ψ ｓ１ αβ " is the first calculated value of the flux linkage to be calculated by the stationary coordinate flux linkage calculator 8 proposed in this paper. The winding resistance R ｓ The voltage drop due to the stator voltage v can be ignored when the rotation speed of the rotating machine 3 is high to a certain extent. ｓ αβ Generally, the stator voltage command value v ｓ αβ＊ By applying a high-pass filter, the problem of initial values ​​can be solved and drift of the integral value due to disturbances can be suppressed. Furthermore, this calculation method uses the differential value of the flux linkage and calculates the flux linkage by integrating this differential value, so it is possible to perform calculations with high response compared to the conventional method of calculating the flux linkage as the product of the inductance component and the stator current.

[0052] Next, we will explain the method of calculating the flux linkage by the rotating coordinate flux linkage calculator 9. In this paper, the calculated value of the flux linkage calculated by the rotating coordinate flux linkage calculator 9 is called the "second flux linkage calculated value."

[0053] First, the voltage equation (5) is converted into the estimated rotor position θ^ ｒ When a rotational coordinate transformation is performed based on the above, the following equation (15) is obtained.

[0054]

[0055] "v" in the above formula (15) ｓ ｄｑ " is the stator voltage on the rotating coordinate system. Also, "ω ＾ ｒ " is an estimated value of the rotation speed, and in this paper it is called "estimated rotation speed." Note that the estimated rotation speed ω ＾ ｒ is calculated within the position estimator 6A as described below. Furthermore, "J" in the above equation (15) is a transformation matrix shown in the following equation (16).

[0056]

[0057] Moreover, by modifying the above equation (16), the following equation (17) is obtained.

[0058]

[0059] By integrating the above equation (17), the calculated interlinkage magnetic flux value Ψ ｓ ｄｑ However, there is a problem that the initial value is unknown. In addition, since the response of equation (17) itself is oscillatory, it is common to use a flux observer to ensure stable calculations. From these points of view, the calculated flux linkage value Ψ ｓ ｄｑ The magnetic flux observer that calculates the above equation (17) can be configured as shown in the following equation (18).

[0060]

[0061] Moreover, the integral formula of the above formula (18) can be expressed as the following formula (19).

[0062]

[0063] The "Ψ" shown in the above equations (18) and (19) ｓ２ ｄｑ" is the second flux linkage to be calculated by the rotating coordinate flux linkage calculator 9 proposed in this paper. Also, "H" is the feedback gain of the flux observer, and "Ψ ｓ，ｒｅｆ ｄｑ " is the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ This is the target value for converging the flux observer, and is required for converging the flux observer. ｓ The voltage drop due to the voltage drop can be ignored when the rotation speed of the rotating machine 3 is high to a certain extent.

[0064] In the above formula (18), the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The target value Ψ that converges ｓ，ｒｅｆ ｄｑ is the second interlinkage magnetic flux calculation value Ψ in the voltage equation (18) above. ｓ２ ｄｑ If the differential of is set to zero, that is, the left side is set to zero, the calculation can be performed using the following equation (20).

[0065]

[0066] As can be seen from the above equations (17) to (19), the second interlinkage magnetic flux calculation value Ψ in the rotating coordinate system ｓ２ ｄｑ The calculation of the first interlinkage magnetic flux calculation value Ψ is performed by the stationary coordinate interlinkage magnetic flux calculator 8 using various quantities of the rotating machine 3 converted into the rotating coordinate. ｓ１ αβ is not used.

[0067] As described above, the method using the flux observer estimates the rotor position θ^ ｒ On the rotating coordinate system based on ｓ ｄｑ The second interlinkage magnetic flux calculation value Ψ is obtained by integrating ｓ２ ｄｑ Furthermore, the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The target value Ψ that converges ｓ，ｒｅｆ ｄｑ The stator voltage v ｓ ｄｑ The target value Ψ in the above formula (20) is calculated based on the following formula. ｓ，ｒｅｆｄｑ The method of using the calculated value as it is is ｓ ｄｑ This means that the differential information of the stator voltage v is ignored, which significantly reduces the response of the calculation. ｓ ｄｑ The target value Ψ based on ｓ，ｒｅｆ ｄｑ The method used in conjunction with this is the calculated flux linkage value Ψ ｓ ｄｑ This means that both the differential value and the steady-state value of the magnetic flux are used, so that the magnetic flux linkage can be calculated with high response.

[0068] In order to design the response of the magnetic flux observer, the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ When the equation is modified so that is a variable, the following equation (21) is obtained.

[0069]

[0070] Here, the true value of the rotor position θ ｒ is not known, so θ ＾ ｒ ≒θ ｒ By approximating this, the following equation (22) is obtained.

[0071]

[0072] By using the above equation (22), if the feedback gain H of the magnetic flux observer is set as in the following equation (23), for example, the convergence response can be improved by ω ｏｂｓ It can be designed to.

[0073]

[0074] The above description will be summarized below. First, the rotating coordinate flux linkage calculator 9 uses the flux observer expressed by the above equations (18), (20), and (23) to calculate the second flux linkage calculation value Ψ ｓ２ ｄｑ In the above equations (18) and (20), the winding resistance R ｓ Voltage drop R ｓ i ｓｑcan be ignored when the rotation speed is higher than a certain level. ｓ ｄｑ As the stator voltage command value v ｓ ｄｑ＊ Use.

[0075] From the above viewpoint, in the first embodiment, a magnetic flux observer is used to calculate the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ , the stator voltage command value v ｓ ｄｑ＊ and the estimated rotation speed ω ＾ ｒ and the most recent calculated value of magnetic flux linkage Ψ ｓ２ ｄｑ The "most recent" means something that is close in time, and may be something that is closest to the present time, for example. ｓ２ ｄｑ " is the previously calculated interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The same meaning will be used in the following description.

[0076] To explain the calculation procedure in more detail, the magnetic flux observer of the first embodiment calculates the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ , the stator voltage command value v ｓ ｄｑ＊ and the estimated rotation speed ω ＾ ｒ and the most recent second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ and the stator voltage command value v ｓ ｄｑ＊ Estimate the rotation speed ω ＾ ｒ The calculation is based on the value obtained by dividing the estimated rotation speed ω ＾ ｒ and the most recent second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The product of "and" corresponds to the third term of the above equation (18). ｓ ｄｑ＊ Estimate the rotation speed ω ＾ ｒ The value obtained by dividing by "corresponds to the above equation (19)."

[0077] To explain the calculation procedure in more detail, the magnetic flux observer of the first embodiment calculates the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ , the stator voltage command value v ｓ ｄｑ＊ and the estimated rotation speed ω ＾ ｒ and the most recent second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ and the stator voltage command value v ｓ ｄｑ＊ Estimate the rotation speed ω ＾ ｒ The value obtained by dividing by the most recent second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The stator voltage command value v ｓ ｄｑ＊ Estimate the rotation speed ω ＾ ｒ The value obtained by dividing by the most recent second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The "difference subtracted from" corresponds to the fourth and fifth terms of the above equation (18).

[0078] To explain the calculation procedure in more detail, the magnetic flux observer of the first embodiment calculates the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ , the estimated rotation speed ω ＾ ｒ and the most recent second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The product of these is the stator voltage command value v ｓ ｄｑ＊ and the stator voltage command value v ｓ２ ｄｑ＊ Estimate the rotation speed ω ＾ ｒ The value obtained by dividing by the most recent second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The first difference corresponds to the first and third terms of the above formula (18), and the second difference corresponds to the fourth and fifth terms of the above formula (18). Note that the first difference is calculated based on the second interlinkage magnetic flux calculated value Ψ as shown in the above formula (17). ｓ２ ｄｑThe second difference is based on the differential value of the second interlinkage magnetic flux calculation value Ψ as shown in the above formula (18). ｓ２ ｄｑ That is, the magnetic flux observer of the first embodiment is based on the steady-state value of the second interlinkage magnetic flux calculated value Ψ ｓ２ ｄｑ The second interlinkage magnetic flux calculation value Ψ is calculated based on both the differential value and the steady-state value of ｓ２ ｄｑ is calculated.

[0079] The second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The calculation procedure of the first embodiment has been explained with respect to the stator voltage v ｓ ｄｑ , stator current i ｓ ｄｑ , the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The signs of the terms may be reversed depending on the polarity of . Furthermore, the above formula (17) can be transformed in various ways depending on how the magnetic flux observer is set. The essential point in the magnetic flux observer of the first embodiment is that the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The components required to calculate the stator voltage command value v ｓ ｄｑ＊ , estimated rotational speed ω ＾ ｒ , and the most recent second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ From this viewpoint, in the first embodiment, the stator voltage command value v ｓ ｄｑ＊ and the estimated rotation speed ω ＾ ｒ and the most recent second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ Based on this, a new second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ By calculating the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The second interlinkage magnetic flux calculation value Ψ is updated. ｓ２ ｄｑ When calculating the stator voltage command value v ｓ ｄｑ＊Instead of the stator voltage v ｓ ｄｑ may be used, and the estimated rotation speed ω ＾ ｒ Instead of the rotation speed ω ｒ In this calculation process, the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ is the stator voltage v ｓ is the rotation speed ω ｒ The calculation is performed so that it converges to the value obtained by dividing by .

[0080] As described above, the flux linkage calculator 7 includes the stationary coordinate flux linkage calculator 8 and the rotating coordinate flux linkage calculator 9. The stationary coordinate flux linkage calculator 8 calculates the first flux linkage calculation value Ψ ｓ１ αβ The rotational coordinate interlinkage magnetic flux calculator 9 calculates the second interlinkage magnetic flux calculated value Ψ ｓ２ ｄｑ The stationary coordinate interlinkage magnetic flux calculator 8 calculates the stator voltage v ｓ αβ is converted into a value on a rotating coordinate system synchronized with the rotation speed of the rotating machine 3, the stator voltage v ｓ αβ The first interlinkage magnetic flux calculation value Ψ is obtained by integrating ｓ１ αβ Furthermore, the rotational coordinate interlinkage magnetic flux calculator 9 calculates the first interlinkage magnetic flux calculated value Ψ ｓ１ αβ The stator voltage v converted into a value on the rotation coordinate system synchronized with the rotation speed of the rotating machine 3 without using ｓ ｄｑ is integrated on the rotation coordinate system to obtain the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The position estimator 6A calculates the first interlinkage magnetic flux calculated value Ψ in accordance with the rotation speed. ｓ１ αβ and the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ and the rotor position of the rotating machine 3 is estimated based on the result of the determination. ｓ１ αβ and the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑThe estimated rotor position θ is an estimated value of the rotor position of the rotating machine 3. ＾ ｒ Calculate the following.

[0081] First interlinkage magnetic flux calculation value Ψ ｓ１ αβ has good accuracy in the low rotation speed range. On the other hand, the quantities of the rotating machine 3 are sinusoidal AC quantities on the stationary coordinate system. Therefore, when the rotation speed of the rotating machine 3 is high and the frequencies of the quantities of the rotating machine 3 are high, the number of sampling points per cycle of the quantities of the rotating machine 3 decreases, making it impossible to accurately detect the sinusoidal waveforms. Furthermore, when the number of sampling points per cycle decreases, the effect of sampling delay increases. As a result, the first interlinkage magnetic flux calculation value Ψ ｓ１ αβ This may cause oscillations in the integral calculation, which may destabilize the estimation of the rotor position.

[0082] On the other hand, on the rotating coordinate system, the quantities of the rotating machine 3 are DC quantities. Therefore, in the calculation on the rotating coordinate system, the problem of the number of sampling points is alleviated even when the rotation speed is high. As a result, in the high rotation speed region, the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ can be calculated with high precision.

[0083] In the method of the first embodiment, the second interlinkage magnetic flux calculation value Ψ to be calculated is calculated using a magnetic flux observer. ｓ２ ｄｑ is the target value Ψ ｓ，ｒｅｆ ｄｑ The second interlinkage magnetic flux calculation value Ψ is set to converge to ｓ２ ｄｑ In the method using the magnetic flux observer, it is not necessary to remove low frequency components, so the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ can be calculated with high response.

[0084] However, in general, in the low rotation speed range, the voltage accuracy of the inverter circuit used as the voltage applicator 2 is poorer than in the high rotation speed range, and furthermore, in the low rotation speed range, the influence of disturbances becomes relatively large. ＾ ｒ As a result, the pulsation of the target value Ψ ｓ，ｒｅｆｄｑ The vibration of the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ The pulsating component contained in

[0085] From the above, in the low rotation speed region, the first interlinkage magnetic flux calculation value Ψ ｓ１ αβ In the high rotation speed range, the second interlinkage magnetic flux calculation value Ψ is used. ｓ２ ｄｑ It is desirable to use

[0086] Fig. 2 is a diagram showing an example of the configuration of the position estimator 6A according to embodiment 1. As shown in Fig. 2, the position estimator 6A according to embodiment 1 includes a rotating coordinate converter 601, a weighted averager 602A, an estimation error calculator 603, a PI controller 604, and an integrator 605.

[0087] First, the rotating coordinate converter 601 calculates the estimated rotor position θ ＾ ｒ Based on this, the first interlinkage magnetic flux calculation value Ψ ｓ１ αβ α-axis component Ψ ｓ１α and the β-axis component Ψ ｓ１β The d-axis component Ψ on the rotating coordinate system ｓ１ｄ and the q-axis component Ψ ｓ１ｑ In this paper, the d-axis component Ψ converted to a value on the rotating coordinate system is ｓ１ｄ and the q-axis component Ψ ｓ１ｑ is also called the "first interlinkage magnetic flux calculation value," and "Ψ ｓ１ ｄｑ " is expressed as

[0088] The weighted averager 602A calculates the first interlinkage magnetic flux calculation value Ψ ｓ１ ｄｑ d-axis component Ψ ｓ１ｄ and the q-axis component Ψ ｓ１ｑ and the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ d-axis component Ψ ｓ２ｄ and the q-axis component Ψ ｓ２ｑ and are weighted averaged for each d-axis and q-axis. In this paper, the calculated value of the flux linkage generated by weighted averaging is called the "third calculated value of the flux linkage" and is called "Ψ ｓ３ ｄｑ In this paper, the third interlinkage magnetic flux calculation value Ψｓ３ ｄｑ The d-axis component and the q-axis component of are respectively "Ψ ｓ３ｄ " and "Ψ ｓ３ｑ " The third interlinkage magnetic flux calculation value Ψ ｓ３ ｄｑ The calculation formula can be expressed by the following formula (24).

[0089]

[0090] In the above formula (24), "k ｗ１ " is the first interlinkage magnetic flux calculation value Ψ ｓ１ ｄｑ is the weighting coefficient of the weighted average given to "k ｗ２ " is the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ These weighting coefficients k ｗ１ , k ｗ２ There is a relationship between these weighting coefficients k ｗ１ , k ｗ２ The value of varies depending on the rotation speed.

[0091]

[0092] 3 is a diagram illustrating the operation of the weighted averager 602A according to the first embodiment. ｗ１ , k ｗ２ is the rotation speed ω ｒ It shows how it changes depending on

[0093] Considering the voltage accuracy of the inverter circuit used as the voltage applicator 2, the influence of disturbances, etc., the calculation of the interlinkage magnetic flux generally becomes accurate with fewer pulsating components at a few percent to several tens of percent or more of the maximum rotation speed of the rotating machine 3. Therefore, in the first embodiment, the rotation speed ω ｒ is 10% of the maximum rotation speed (ω ｒ１０ Specifically, as shown in FIG. 3, the weighting is changed before and after the rotation speed ω ｒ is 5% of the maximum rotation speed (ω ｒ５ ) or less, the weighting coefficient k ｗ１ is set to 1. Weighting coefficient k ｗ１Setting ω to 1 means that only the calculated value of the interlinkage magnetic flux obtained on the stationary coordinate system is used. ｒ１５ ) or higher, the weighting coefficient k ｗ２ is set to 1. Weighting coefficient k ｗ２ Setting is 1 means that only the calculated value of the interlinkage magnetic flux obtained on the rotation coordinate system is used. ｒ ω ｒ５ and ω ｒ１５ In the rotational speed range between ｒ For the lamp characteristics, the weighting coefficient k ｗ１ , k ｗ２ The ramp characteristic is the increase or decrease in output over time.

[0094] The estimation error calculator 603 calculates the third interlinkage magnetic flux calculated value Ψ as described above. ｓ３ ｄｑ Using the estimated rotor position θ ＾ ｒ Estimation error of - (θ ＾ ｒ -θ ｒ ) is calculated. Estimation error - (θ ＾ ｒ -θ ｒ The calculation of ( ) is performed in the following procedure.

[0095] First, the calculated value of the interlinkage magnetic flux inductance fluctuation is calculated as "Ψ ｓｖａｒ，ｃａｌｃ ｄｑ The calculated value of this flux linkage inductance fluctuation is expressed as Ψ ｓｖａｒ，ｃａｌｃ ｄｑ is the third interlinkage magnetic flux calculated value Ψ calculated by the weighted averager 602A. ｓ３ ｄｑ and the average inductance component L ｓａｖｇ and the stator current i ｓ ｄｑ Using the above, it can be expressed by the following equation (26).

[0096]

[0097] The above formula (26) can be derived from the relationship between the above formulas (9) and (10).

[0098] Furthermore, the calculated value Ψ of the flux linkage inductance fluctuation shown in the above equation (26) ｓｖａｒ，ｃａｌｃ ｄｑ and the estimated value Ψ of the flux linkage inductance fluctuation component shown in the above equation (11). ＾ ｓｖａｒ ｄｑ is the estimation error - (θ ＾ ｒ -θ ｒ ) (= θ ｒ -θ ＾ ｒ ) can be expressed as in the following equation (27).

[0099]

[0100] In the above equation (27), the estimated rotor position θ ＾ ｒ and the true value of the rotor position θ ｒ and are roughly equal, that is, θ ＾ ｒ ≒θ ｒ If it can be approximated as sin(2(θ ｒ -θ ＾ ｒ ))≒2(θ ｒ -θ ＾ ｒ ) can be approximated as follows. Therefore, the above equation (27) can be expressed as the following equation (28).

[0101]

[0102] Therefore, the estimated error calculator 603 calculates the estimated error −(θ ＾ ｒ -θ ｒ ) can be calculated.

[0103] The position estimator 6A calculates the estimated error −(θ ＾ ｒ -θ ｒ ) is subjected to PI control and then further integrated to converge to zero, thereby estimating the rotor position θ^ ｒ Specifically, as shown in FIG. 2, the PI controller 604 generates the estimation error −(θ ＾ ｒ -θ ｒ) is subjected to proportional integral processing to estimate the rotation speed ω^ ｒ The integrator 605 generates the estimated rotation speed ω̂ ｒ By integrating the estimated rotor position θ^ ｒ That is, the estimated error -(θ ＾ ｒ -θ ｒ ) PI control output is estimated rotation speed ω^ ｒ and the output of the integrator 605 is the estimated rotor position θ^ ｒ This becomes:

[0104] The method of the first embodiment described above basically calculates the stator voltage (v ｓ αβ or v ｓ ｄｑ ) to calculate the flux linkage. On the other hand, as mentioned above, there is also a method of calculating the flux linkage by the product of the inductance component and the stator current. In this method, the calculation in stationary coordinates uses, for example, the above formula (6), and in rotating coordinates uses, for example, the above formula (9), and θ^ ｒ ≒θ ｒ When using a flux observer, the target value Ψ ｓ，ｒｅｆ ｄｑ However, the method of calculating the flux linkage by the product of the inductance component and the stator current does not include the true value θ of the rotor position, which should be included in the calculated value. ｒ and the estimated rotor position θ ＾ ｒ information about the difference in inductance between the

[0105] Therefore, in an estimation method for estimating the rotor position using the inductance fluctuation component of the rotating machine 3, if a method of calculating the product of the inductance component and the stator current is adopted, there is a drawback in that information that should be used for estimating the rotor position is lost, and there is a disadvantage in that both the calculation accuracy of the flux linkage and the responsiveness of the position estimation are reduced.

[0106] In contrast to this, the technique of the first embodiment employs an estimation method for estimating the rotor position using the inductance fluctuation component of the rotating machine 3, while also estimating the stator voltage (v ｓ αβ or v ｓ ｄｑ ) to obtain the first or second interlinkage magnetic flux calculation value (Ψ ｓ１ αβ or Ψ ｓ２ ｄｑ ) and calculates the target value Ψ of the magnetic flux observer. ｓ，ｒｅｆ ｄｑ The stator voltage v ｓ ｄｑ Since it is calculated based on the flux linkage (Ψ ｓ１ αβ or Ψ ｓ２ ｄｑ ) and the target value Ψ ｓ，ｒｅｆ ｄｑ This includes information about the difference in inductance, which enables the rotor position estimation process to achieve both high calculation accuracy and responsiveness.

[0107] As described above, the control device for a rotating machine according to the first embodiment includes a position estimator that estimates the rotor position of the rotating machine and outputs an estimated rotor position, a stationary coordinate flux linkage calculator that calculates a first flux linkage calculation value, and a rotating coordinate flux linkage calculator that calculates a second flux linkage calculation value. The stationary coordinate flux linkage calculator calculates the first flux linkage calculation value by integrating the stator voltage on the stationary coordinate without converting it into a value on the rotating coordinate synchronized with the rotational speed of the rotating machine. The rotating coordinate flux linkage calculator calculates the second flux linkage calculation value by integrating the stator voltage converted into a value on the rotating coordinate synchronized with the rotational speed of the rotating machine without using the first flux linkage calculation value. The position estimator calculates the estimated rotor position using at least one of the first flux linkage calculation value and the second flux linkage calculation value according to the rotational speed. According to the control device for a rotating machine of the first embodiment, in the low rotational speed range, the first flux linkage calculation value, which is accurate in the low rotational speed range, is used, and in the high rotational speed range, the second flux linkage calculation value, which is accurate in the high rotational speed range, is used. Therefore, it is possible to obtain a remarkable effect not previously seen in the past, that is, to estimate the rotor position stably and with high accuracy in a wide rotational speed range from the low rotational speed range to the high rotational speed range.

[0108] In the method of the first embodiment, the second flux linkage calculation value can be calculated using a flux observer. When the flux observer is used, the calculation is performed so as to converge to a value obtained by dividing the stator voltage by the rotation speed.

[0109] Furthermore, in the control device for a rotating machine according to the first embodiment, the position estimator may include a weighted averager that calculates a third flux linkage calculated value by taking a weighted average of the first flux linkage calculated value and the second flux linkage calculated value. If such a weighted averager is provided, it becomes possible to output an estimated rotor position with high accuracy without having to determine whether to use one or both of the first flux linkage calculated value and the second flux linkage calculated value depending on the rotation speed.

[0110] Furthermore, in the control device for a rotating machine according to the first embodiment, the position estimator can estimate the rotor position from the flux linkage inductance fluctuation component of the rotating machine, which is generated by the inductance fluctuation component and the stator current. The inductance fluctuation component used for position estimation is the latter component when the inductance of the rotating machine is divided into an average component that does not change depending on the rotor position and a fluctuation component that changes at twice the frequency at which the rotor position changes. Estimating the rotor position using such an inductance fluctuation component can achieve a remarkable effect not previously achieved, such as being able to estimate the rotor position with high response and high accuracy.

[0111] Embodiment 2. Fig. 4 is a diagram showing an example of the configuration of a control device 1B for a rotating machine according to embodiment 2. Compared to the configuration shown in Fig. 1, in Fig. 4, the position estimator 6A is replaced with a position estimator 6B. The other configuration is the same as or equivalent to that in Fig. 1, and the same or equivalent components are designated by the same reference numerals, and redundant explanations will be omitted.

[0112] 5 is a diagram showing an example of the configuration of a position estimator 6B according to the second embodiment. Compared to the configuration shown in FIG. 2, in FIG. 5, the weighted averager 602A is replaced with a weighted averager 602B. Also, compared to the configuration shown in FIG. 2, in FIG. 5, a notch filter 608 is added between the estimation error calculator 603 and the PI controller 604. The other configuration is the same or equivalent to that in FIG. 2, and the same or equivalent components are designated by the same reference numerals, and redundant description will be omitted.

[0113] The notch filter 608 is a filter that removes frequency components of the rotation speed of the rotating machine 3. The transfer function of the notch filter 608 can be expressed as in the following equation (29).

[0114]

[0115] In the above equation (29), ω ０ is a frequency component that is removed by the notch filter 608, and is referred to as the "resonant angular frequency" in this paper. ｒis the damping ratio. In the inverter circuit used as the voltage applicator 2, when there is an influence of voltage accuracy or disturbance, the first interlinkage magnetic flux calculated value Ψ ｓ１ αβ , the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ , and the estimation error −(θ ＾ ｒ -θ ｒ ) pulsates at the fundamental frequency, which is the frequency of the rotation speed of the rotating machine 3. Therefore, the resonance angular frequency ω ０ is the rotation speed ω ｒ By setting the resonant angular frequency ω to ωt and performing filtering, it is possible to reduce the voltage accuracy and pulsation caused by the influence of disturbances. ０ is the rotation speed ω ｒ It is variable depending on the

[0116] However, the rotation speed ω ｒ When the resonant angular frequency ω of the notch filter 608 is low, ０ If the resonant angular frequency ω of the notch filter 608 is set lower than the angular frequency of the position estimation response when the position estimator 6B estimates the rotor position, the processing of the notch filter 608 and the processing of the position estimation will interfere with each other, impairing the responsiveness and accuracy of the position estimation. ０ This limits the angular frequency of the position estimation response. ｒ If the frequency of is lower than the angular frequency of the position estimation response, the estimated rotation speed ω ＾ ｒ Therefore, it becomes difficult to remove the pulsating component contained in the rotation speed ω ｒ If the frequency of the second interlinkage magnetic flux calculation value Ψ is lower than the angular frequency of the position estimation response, ｓ２ ｄｑ Since the influence of vibration of the target value in the above formula (18) is large, it is appropriate to use the first flux linkage calculation value calculated by the stationary coordinate flux linkage calculator.

[0117] The weighted averager 602B calculates the first interlinkage magnetic flux calculation value Ψ converted into the rotating coordinate system as in the above equations (24) and (25). ｓ１ ｄｑ and the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑand the weighted average is calculated to obtain the third interlinkage magnetic flux calculation value Ψ ｓ３ ｄｑ The weighting coefficient k of the weighted average is calculated. ｗ１ , k ｗ２ is the rotation speed ω ｒ 6 according to the rotation speed ω. FIG. 6 is a diagram illustrating the operation of the weighted averager 602B according to the second embodiment. The horizontal axis of FIG. 6 represents the rotation speed ω. ｒ However, in the following explanation, it will be treated as meaning angular frequency.

[0118] As shown in FIG. ｒ The angular frequency of the position estimation response is ω ｅｓｔ 5 percent lower angular frequency (ω ｅｓｔｍ５ ) In the following cases, the weighting coefficient k ｗ１ is set to 1, and the first interlinkage magnetic flux calculation value Ψ ｓ１ αβ Also, the rotation speed ω ｒ The angular frequency of the position estimation response is ω ｅｓｔ 5% higher angular frequency (ω ｅｓｔｐ５ ) or more, the weighting coefficient k ｗ２ is set to 1, and the second interlinkage magnetic flux calculation value Ψ ｓ２ ｄｑ Also, the rotation speed ω ｒ The angular frequency of ω ｅｓｔｍ５ and ω ｅｓｔｐ５ If the rotation speed ω ｒ The weighting coefficient k is used for the lamp characteristics for the angular frequency of ｗ１ , k ｗ２ Change the

[0119] In this paper, the angular frequency ω ｅｓｔ The rotational speed ω corresponding to ｒ is sometimes referred to as a "first speed." This first speed is a rotation speed that corresponds to the angular frequency of the position estimation response when the position estimator 6B estimates the rotor position.

[0120] As described above, in the control device for a rotating machine according to the second embodiment, the weighted averager included in the position estimator calculates the third flux linkage calculation value by increasing the weighting of the first flux linkage calculation value when the rotational speed is less than a first speed, which is a preset speed, and by increasing the weighting of the second flux linkage calculation value when the rotational speed is equal to or greater than the first speed. The control device for a rotating machine according to the second embodiment includes the functions of the first embodiment and can therefore achieve the effects of the first embodiment. Furthermore, the control device for a rotating machine according to the second embodiment can achieve highly responsive and highly accurate calculation processing by using a notch filter and increasing the weighting of the second flux linkage calculation value calculated by the rotating coordinate flux linkage calculation unit when the rotational speed is high. Furthermore, when the rotational speed is low, it can achieve highly responsive and highly accurate calculation processing by increasing the weighting of the first flux linkage calculation value calculated by the stationary coordinate flux linkage calculation unit, which is relatively less affected by voltage accuracy and disturbances.

[0121] The functions of the control devices 1A and 1B for rotating machines described in the first and second embodiments can be realized using a processing circuit. The functions of the control devices 1A and 1B are the functions of the controller 5, the position estimators 6A and 6B, and the flux linkage calculator 7.

[0122] Fig. 7 is a diagram showing a first hardware configuration example of the rotating machine control device 1A, 1B according to the first and second embodiments. Fig. 8 is a diagram showing a second hardware configuration example of the rotating machine control device 1A, 1B according to the first and second embodiments. The processing circuit may be dedicated hardware such as the dedicated processing circuit 10 shown in Fig. 7, or may be configured to include a processor 11 shown in Fig. 8 and a storage device 12 that stores a program for operating the processor 11.

[0123] When dedicated hardware is used, the dedicated processing circuit 10 may be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. Each function of the control devices 1A and 1B may be realized by a processing circuit, or the functions may be realized together by a processing circuit.

[0124] When the processor 11 and the storage device 12 are used, the functions of the control devices 1A and 1B are realized by software, firmware, or a combination thereof. The software or firmware is written as a program and stored in the storage device 12. The processor 11 reads and executes the program stored in the storage device 12. These programs can also be considered to cause a computer to execute the procedures and methods executed by the processor 11. The storage device 12 corresponds to semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), or EEPROM (Electrically Erasable Programmable Read Only Memory). The semiconductor memory may be either non-volatile or volatile memory. The storage device 12 may also be a magnetic disk, flexible disk, optical disk, compact disk, minidisc, or DVD (Digital Versatile Disc), in addition to semiconductor memory. The functions of the control devices 1A and 1B may be partially implemented by hardware and partially implemented by software or firmware.

[0125] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, and parts of the configurations may be omitted or modified without departing from the spirit of the invention.

[0126] For example, although the voltage applicator 2 has been described as a three-phase inverter circuit, it may be an inverter with a different number of phases, or various voltage applicators such as a multilevel inverter, such as a three-level inverter or a five-level inverter, may be used.

[0127] 1A, 1B Control device, 2 Voltage applicator, 3 Rotating machine, 4 Current detector, 5 Controller, 6A, 6B Position estimator, 7 Flux linkage calculator, 8 Stationary coordinate flux linkage calculator, 9 Rotating coordinate flux linkage calculator, 10 Dedicated processing circuit, 11 Processor, 12 Storage device, 17 Stator, 18 Rotor, 501 Current command calculator, 502 Three-phase to two-phase converter, 503 Rotating coordinate converter, 504 Current controller, 505 Rotating coordinate inverse converter, 506 Two-phase to three-phase converter, 601 Rotating coordinate converter, 602A, 602B Weighted averager, 603 Estimation error calculator, 604 PI controller, 605 Integrator, 608 Notch filter.

Claims

a controller that outputs a stator voltage command value for driving the rotating machine based on the stator current and the estimated rotor position; a voltage applicator that applies a drive voltage to the rotating machine based on the stator voltage command value; a stationary coordinate flux linkage calculator that calculates a first flux linkage calculation value by integrating the stator voltage on stationary coordinates without converting it into a value on rotating coordinates synchronized with the rotational speed of the rotating machine; and a rotating coordinate flux linkage calculator that calculates a second flux linkage calculation value by integrating the stator voltage converted into a value on rotating coordinates synchronized with the rotational speed of the rotating machine without using the first flux linkage calculation value, wherein the position estimator calculates the estimated rotor position using at least one of the first flux linkage calculation value and the second flux linkage calculation value in accordance with the rotational speed.

2. The control device for a rotating machine according to claim 1, characterized in that the rotating coordinate interlinkage magnetic flux calculator performs calculations so that the second interlinkage magnetic flux calculation value converges to a value obtained by dividing the stator voltage by the rotational speed.

3. A control device for a rotating machine according to claim 1 or 2, characterized in that the position estimator estimates the rotor position using a third calculated flux linkage value obtained by weighting the first calculated flux linkage value and the second calculated flux linkage value.

4. A control device for a rotating machine according to claim 3, characterized in that the position estimator increases the weighting of the first flux linkage calculation value when the rotation speed is less than a first speed that is a preset set speed, and increases the weighting of the second flux linkage calculation value when the rotation speed is equal to or greater than the first speed.

5. The control device for a rotating machine according to claim 4, wherein the first speed is a rotation speed corresponding to an angular frequency of a position estimation response when the position estimator estimates the rotor position.

6. A control device for a rotating machine according to any one of claims 1 to 5, characterized in that the rotating machine is a rotating machine having an inductance fluctuation component whose inductance changes depending on rotor position.

7. The control device for a rotating machine according to claim 6, wherein the rotating machine is a rotating machine that does not have a magnet in its rotor.

8. The control device for a rotating machine according to claim 6, wherein the rotating machine is a rotating machine having a permanent magnet in the rotor.

9. A control device for a rotating machine according to any one of claims 6 to 8, characterized in that the position estimator estimates the rotor position from the flux linkage inductance fluctuation component of the flux linkage of the rotating machine, which is generated by the inductance fluctuation component and the stator current.

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