JP7302140B2 - Drive for synchronous reluctance motor - Google Patents

Description

The present invention provides a d-axis whose axial phase is the phase of the salient mechanical poles in the order (also called "positive") or the salient mechanical poles in reverse (also called "negative") determined by the mechanical structure of the rotor, and For a synchronous reluctance motor having inter-axis magnetic flux interference (hereinafter abbreviated as "d-q inter-axis magnetic flux interference") between the d-axis and the q-axis on a dq synchronous coordinate system composed of orthogonal q-axes The present invention relates to a driving device, and more particularly to a driving device that enables the motor to be driven most simply and rationally. Note that "interaxial magnetic flux interference" is also called "interaxial magnetic interference" and "interaxial interference". These three terms are synonymous.

In the present invention, a two-dimensional plane is grasped in terms of polar coordinates, and the three terms "angle", spatial "position" and spatial "phase" are used synonymously. These units are "rads" or "degrees". The positive direction of angle, spatial position, and spatial phase in the present invention may be defined as left (counterclockwise) or right (clockwise). However, in this specification, in order to maintain the simplicity of explanation, the positive direction of the angle, spatial position, and spatial phase is defined as left rotation (counterclockwise rotation) to describe the present invention. This does not lose the generality of the invention.

As the name of the magnetic flux generated by the stator current of a synchronous reluctance motor, the three terms "stator magnetic flux", "stator interlinkage magnetic flux" and "stator reaction magnetic flux" are used synonymously. In principle, the present invention uses the simple term stator flux.

In the present invention, the term "equivalent value" is used with respect to signals such as stator voltage and stator current. The equivalent value is a general term for the true value, approximate value, estimated value, command value, etc. of the signal.

In order for a synchronous reluctance motor to exhibit high control performance, it is essential to control the stator current, and a vector control method is conventionally known as a control method for this purpose. Conventional vector control methods require information on the phase of forward mechanical salient poles or the phase of reverse mechanical salient poles determined by the mechanical structure of the rotor. These mechanical phases of the rotor are simply called "rotor phases" and are easily detected by a position/speed sensor such as an encoder attached to the rotor.

Consider FIG. As the rotor phase, the forward mechanical salient pole phase is adopted in FIG. 1(a), and the reverse mechanical salient pole phase is adopted in FIG. 1(b). Both figures depict two coordinate systems, a dq synchronous coordinate system and an αβ fixed coordinate system, as representative two-axis orthogonal coordinate systems useful for drive control of a synchronous reluctance motor. The dq synchronous coordinate system means a coordinate system in which the phase of the d-axis, which is the main axis, is synchronized with the phase of the salient forward mechanical poles or the salient reverse mechanical poles of the rotor without a phase difference. On the other hand, the αβ fixed coordinate system means a coordinate system in which the phase of the α axis, which is the main axis, is aligned with the reference position of the stator (generally, the center position of the three-phase u-phase winding). The sub-axis of each coordinate system is arranged at a position leading the phase by π/2 [rad] with respect to the base axis. The speed of the dq synchronous coordinate system synchronized with the forward mechanical salient poles or reverse mechanical salient poles of the rotor without phase difference is the same as the electric speed ω2n of the rotor. The rotor phase with respect to the α-axis is expressed as "θα". Vector control of a conventional synchronous reluctance motor basically requires a rotor phase “θα” with respect to the α axis. In the following description, the phase relationship between the base axis and sub-axis of all coordinate systems is the same as in FIG. 1 in order to maintain the simplicity of the description.

In the present invention, a γδ magnetic salient polar coordinate system is defined as a new two-axis orthogonal coordinate system consisting of a γ axis as a base axis and a δ axis as a secondary axis. The γδ magnetic salient pole coordinate system is a coordinate system in which the phase of the salient forward magnetic poles or the phase of the salient reverse magnetic poles of the rotor is selected as the phase of the γ axis, which is the basic axis of the orthogonal two axes. Consider FIG. FIG. 2 schematically shows the relationship between the dq synchronous coordinate system and the γδ magnetic salient pole coordinate system. FIG. 2(a) shows an example in which the forward salient pole phase is selected as the basic axis phase in both coordinate systems, and FIG. 2(b) shows an example in which the reverse salient pole phase is selected as the basic axis phase in both coordinate systems. ing. It should be pointed out that the phase lead and phase lag of the γδ magnetic salient pole coordinate system with respect to the dq synchronous coordinate system change with the stator current. FIG. 2 is just one example showing the relationship between the two coordinate systems. In the present invention, the two-axis orthogonal coordinate system aiming at convergence to the γδ magnetic salient polar coordinate system is also referred to as the “γδ magnetic salient polar coordinate system”.
Note that inter-axis magnetic flux interference between the γ-axis and the δ-axis theoretically disappears on the γδ magnetic salient polar coordinate system. In practice, it is reduced in a state corresponding to extinction. This characteristic on the γδ magnetic salient polar coordinate system was newly clarified by the present invention. ) to analyze and explain without any doubt.

In a synchronous reluctance motor with dq inter-axis flux interference, the dq synchronous coordinate system and the γδ magnetic salient pole coordinate system are different from each other, as in the example of FIG. However, in a synchronous reluctance motor with no dq inter-axis flux interference (ie ideal), both coordinate systems will be identical. The motor to which the present invention is directed is a synchronous reluctance motor having dq inter-axis magnetic flux interference.

Synchronous reluctance motors have features such as being suitable for high-speed rotation, robustness, excellent environmental resistance, low cost, and high recyclability. On the other hand, they generally have the drawback of having strong dq inter-axis magnetic flux interference characteristics. In order to obtain the desired performance that takes advantage of the characteristics of the synchronous reluctance motor, this drive is based on vector control centered on stator current control. Conventional vector control methods perform current control on a dq synchronous coordinate system, and rotor phase is essential for this performance. Vector control methods for synchronous reluctance motors include the sensor-based vector control method, which detects the rotor phase using position/speed sensors, and the sensorless vector control method, which presumably obtains the rotor phase without using position/speed sensors. vector control method”.

When the sensor-based vector control method is used as the standard, the most important technical problem in the sensorless vector control method is the rotor phase estimation. Rotor phase estimation methods are broadly classified into a "driving voltage/current utilization method" that uses driving voltage and current and a "high-frequency voltage application method" that applies a high-frequency voltage for phase search. In order to obtain high rotor phase estimation performance in sensorless vector control of a synchronous reluctance motor, it is generally necessary to consider the dq inter-axis magnetic flux interference characteristic, which is a drawback of the synchronous reluctance motor. Based on this recognition, for example, Non-Patent Document 1 discusses and presents a rotor phase estimation method that eliminates "the influence of dq inter-axis magnetic flux interference on the phase estimation performance by the high-frequency voltage application method". The rotor phase to be estimated in the literature is the mechanical phase of the rotor. More specifically, it is the phase of forward mechanical salient poles or reverse mechanical salient poles determined by the mechanical structure of the rotor.

The conventional vector control method for a synchronous reluctance motor with dq inter-axis magnetic flux interference configures a current control system on a dq synchronous coordinate system, and has the following problems and problems (see ( 3) and (4)).
(a) In order to obtain high current control performance, it is necessary to adopt a special controller that considers dq inter-axis magnetic flux interference. When using a standard PI-type current controller, the influence of the dq inter-axis magnetic flux interference caused the deterioration of the current control performance.
(b) In order to determine the current command value corresponding to the torque command value and to bring about efficient driving, it is necessary to prepare a special command converter considering the dq inter-axis magnetic flux interference. The configuration of a special command converter is considerably complicated compared to the case where there is no dq inter-axis magnetic flux interference for which a simple analytical optimum solution can be used.
(c) In rotor phase estimation, in order to accurately estimate the mechanical rotor phase (d-axis phase), it is necessary to newly prepare a phase estimator that considers dq inter-axis magnetic flux interference. If this is ignored, a phase estimation error occurs depending on the strength of the dq inter-axis magnetic flux interference.

C. Li, G. Wang, G. Zhang, andD. Xu: "Eliminating Position Error Caused by Cross-Coupling Effect in Saliency-Based Sensorless Control of SynRMs", 2018 21st International Conference on Electrical Ma chines and Systems (ICEMS), pp. 1600-1605 (2018) Shinji Shinnaka: "Detailed Explanation: Vector Control Technology for Synchronous Motors", ISBN 978-4-501-11820-4, Tokyo Denki University Press (2019)

The present invention has been made under the above background, and its object is to provide a driving apparatus which solves the above-mentioned problems and problems in driving a synchronous reluctance motor having dq inter-axis magnetic flux interference.

In order to achieve the above object, the invention of claim 1 provides a d-axis (basic axis) whose axis phase is the phase of forward mechanical salient poles or reverse mechanical salient poles determined by the mechanical structure of a rotor, and A drive device for a synchronous reluctance motor having inter-axis magnetic flux interference between the d-axis and the q-axis on a dq synchronous coordinate system composed of two orthogonal axes with the q-axis (secondary axis) orthogonal to each other, , γ-axis (basic axis) and δ-axis (secondary axis), and between the γ-axis and δ-axis, the inter-axis magnetic flux interference is reduced in the state of disappearance. and the phase evaluated from the stator reference position in the γδ magnetic salient polar coordinate system is θαγ. and stator current control means for performing at least part of the current control.

を実質満足するように、該座標系位相決定手段を構成したことを特徴とする。The invention of claim 2 is the drive device of claim 1, wherein the d-axis inductance and the q-axis inductance of the synchronous reluctance motor on the dq synchronous coordinate system are Ld and Lq, respectively, and the d-axis and the q-axis are Let Lc be the interference inductance indicating the inter-axis magnetic flux interference between the two, and let θγ be the phase difference between the d-axis and the γ-axis with respect to the γ-axis.

The coordinate system phase determining means is constructed so as to substantially satisfy

According to a third aspect of the present invention, there is provided a driving apparatus according to the first aspect, wherein the phase θαγ The coordinate system phase determining means is configured to presumptively determine .

を実質満足するようにＬγ、Ｌδを定め、定めたＬγ、Ｌδあるいはこの処理値を用いて、該座標系位相決定手段、該γδ磁気突極座標系上の該固定子電流制御手段の少なくともいずれかの手段を設計または構成したことを特徴とする。The invention of claim 4 is the drive device of claim 1, wherein the d-axis inductance and the q-axis inductance of the synchronous reluctance motor on the dq synchronous coordinate system are Ld and Lq, respectively, and the d-axis and the q-axis are Let Lc be the interference inductance indicating the inter-axis magnetic flux interference between the two, and let Lγ and Lδ be the γ-axis inductance and the δ-axis inductance used in the design or construction of the means of the driving device.

Lγ and Lδ are determined so as to substantially satisfy the above, and using the determined Lγ and Lδ or the processed values, at least one of the coordinate system phase determination means and the stator current control means on the γδ magnetic salient pole coordinate system characterized by designing or configuring the means of

The inductances Li and Lm defined in equation (2b) are called common-phase inductance and mirror-phase inductance, respectively. Also, the function sgn in the formula (2c) means a sign function (signum function), as is clear from the definition of the formula.

The effect of the invention of claim 1 will be described. A mathematical model of a synchronous reluctance motor having dq inter-axis magnetic flux interference is described by the following equations (3) (circuit equation) and (4) (torque generation equation).

また、（３）、（５）式における記号「ｓ」は微分演算子を意味する。２×１ベクトルｖ１、ｉ１、φ１は、各々固定子電圧、固定子電流、固定子磁束である。τは発生トルクであり、ω２ｎは回転子の電気速度である。また、Ｎｐ、Ｒ１は各々極対数、巻線抵抗である。同相インダクタンスＬｉ、鏡相インダクタンスＬｍの定義は、（２ｂ）式のとおりである。なお、鏡相インダクタンスＬｍの極性は、（２ｂ）式の定義より自明のように、回転子位相を順機械突極位相とする場合には正、逆機械突極位相とする場合には負となる。（３ｄ）式に用いられたＬｃが、ｄｑ軸間磁束干渉を表現した干渉インダクタンスである。干渉インダクタンスＬｃは、必ずしも一定ではなく、一般的には、その極性および大きさは固定子電流に応じて変化する。The 2×2 matrix D used in equation (3) is called a D factor and is defined as follows.

Also, the symbol "s" in equations (3) and (5) means a differential operator. The 2×1 vectors v1, i1, φ1 are the stator voltage, stator current, and stator flux, respectively. τ is the generated torque and ω2n is the rotor electrical speed. Np and R1 are the number of pole pairs and winding resistance, respectively. The definitions of the common-mode inductance Li and the mirror-phase inductance Lm are given by equation (2b). The polarity of the mirror phase inductance Lm is positive when the rotor phase is the forward mechanical salient pole phase, and is negative when the rotor phase is the reverse mechanical salient pole phase, as is obvious from the definition of equation (2b). Become. Lc used in equation (3d) is the interference inductance expressing the dq inter-axis magnetic flux interference. The interference inductance Lc is not necessarily constant, and generally its polarity and magnitude vary with the stator current.

As those skilled in the art can easily understand from equation (3) (circuit equation) and equation (4) (torque generation equation), a synchronous reluctance motor having dq inter-axis magnetic flux interference is defined as When drive control is performed by a vector control system centering on current control, problems and problems (a) to (c) described in the section "Background Art" are encountered.

さらには、位相差θγを次式のように選定する。

この上で、次の２×２行列であるベクトル回転器Ｒを次式のように定義する。

Here, the arc tangent value θc of the relative ratio between the interference inductance Lc and the mirror phase inductance Lm (see formula (2b) for this definition) is defined as follows.

Furthermore, the phase difference θγ is selected as in the following equation.

Based on this, the following 2×2 matrix vector rotator R is defined as follows.

また、（４）式に（９ｃ）式の関係を利用すると、新たなトルク発生式として、γ軸電流、δ軸電流を用いた次式を得る。

Applying the vector rotator R to both sides of equation (3a) yields a new circuit equation as follows.

Further, by using the relationship of the formula (9c) for the formula (4), the following formula using the γ-axis current and the δ-axis current is obtained as a new torque generation formula.

なお、同相インダクタンスＬｉは、（１１ｂ）式の第１行に示しているように不変である。すなわち、同相インダクタンスに関しては、次の関係が成立している。

Equation (9d), which constitutes the circuit equation, states that "on the γδ magnetic salient pole coordinate system, even a synchronous reluctance motor having dq interaxis magnetic flux interference does not generate interaxial magnetic flux interference between the γ and δ axes." It is shown that. In addition, the circuit equation of expression (9) and the torque generation expression of expression (10) are "a circuit equation of a synchronous reluctance motor having magnetic flux interference between dq axes on a γδ magnetic salient pole coordinate system, and the torque generation expression is It is formally the same as the circuit equation and torque generation equation on the dq synchronous coordinate system of a synchronous reluctance motor without magnetic flux interference (in other words, ideal). More specifically, it shows that "in both mathematical models, the following formal permutation of the stator inductance is established".

Note that the common-mode inductance Li is unchanged as shown in the first line of equation (11b). That is, the following relationship holds for the common-mode inductance.

According to the first aspect of the invention, stator current control can be performed on a γδ magnetic salient pole coordinate system in which interaxial magnetic flux interference does not occur. At this time, on the γδ magnetic salient pole coordinate system, even a synchronous reluctance motor having dq inter-axis magnetic flux interference is equivalent to a synchronous reluctance motor having no dq inter-axis magnetic flux interference (in other words, an ideal) synchronous reluctance motor It is possible to secure the characteristic that it can be handled. According to the invention of claim 1, this fact is "a synchronous reluctance motor without dq inter-axis magnetic flux interference (in other words, an ideal) synchronous reluctance motor with dq inter-axis magnetic flux interference. Current control, efficiency drive, and coordinate system phase estimation similar to the case of , can be achieved, and the problems and problems pointed out in the background art section can be immediately solved.

Next, the effect of the invention of claim 2 will be described. According to the invention of claim 2, when the phase difference between the d-axis and the γ-axis with respect to the γ-axis is θγ, the phase difference θγ is determined so as to substantially satisfy the equation (1). The formula (1) used in the invention of claim 2 is the same as the sum of the formulas (6) and (7). As is clear from this fact, according to the second aspect of the invention, "when the d-axis phase θα of the dq synchronous coordinate system can be accurately grasped by a position/speed sensor or the like, the phase θαγ of the γδ magnetic salient pole coordinate system can be immediately determined, and the γδ magnetic salient pole coordinate system can be immediately constructed.” As a result, the effect that "the effect of the invention of claim 1 can be enhanced" can also be obtained. The above phase relationship is described by the following equation (see FIG. 2).

Next, the effect of the invention of claim 3 will be described. Vector control methods are roughly divided into sensor-based vector control methods and sensorless vector control methods. According to the invention of claim 1, "a synchronous reluctance motor having dq inter-axis magnetic flux interference on the γδ magnetic salient pole coordinate system does not have dq inter-axis magnetic flux interference on the dq synchronous coordinate system (in other words, an ideal ) can be handled in the same way as a synchronous reluctance motor.” The invention of claim 3 utilizes this characteristic obtained by the invention of claim 1 to drive a synchronous reluctance motor having dq inter-axis magnetic flux interference without a sensor. That is, according to the third aspect of the invention, "a sensorless drive that guarantees the same performance as a synchronous reluctance motor without dq inter-axis magnetic flux interference for a synchronous reluctance motor having dq inter-axis magnetic flux interference is possible." effect is obtained. As a result, the effect that "the effect of the invention of claim 1 can be enhanced" can also be obtained.

Next, the effects of the invention of claim 4 will be described. According to the invention of claim 1, "a synchronous reluctance motor having dq inter-axis magnetic flux interference on the γδ magnetic salient pole coordinate system does not have dq inter-axis magnetic flux interference on the dq synchronous coordinate system (in other words, an ideal ) can be handled in the same way as a synchronous reluctance motor.” The invention of claim 4 utilizes this characteristic obtained by the invention of claim 1 to provide a coordinate system phase determination means for a synchronous reluctance motor having dq inter-axis magnetic flux interference, and a fixation on the γδ magnetic salient pole coordinate system. This is an attempt to design and implement child current control means. In the fourth aspect of the invention, "the γ-axis inductance and the δ-axis inductance (see formula (2a)) used for designing or configuring the means" are, as shown in the analytical formula (9e), "γδ magnetic salient polar coordinates It is the same as the actual γ-axis inductance and δ-axis inductance when inter-axis magnetic flux interference on the system is eliminated. As a result, according to the invention of claim 4, "design of conventional coordinate system phase determination means developed for synchronous reluctance motors without dq inter-axis magnetic flux interference (in other words, ideal)・The realization method, likewise the design and realization method of the conventional stator current control means, can be used immediately. As a result, the effect that "the effect of the invention of claim 1 can be enhanced" can also be obtained.

Diagram showing an example of relationship between the αβ fixed coordinate system and the dq synchronous coordinate system (forward mechanical salient pole phase reference, reverse mechanical salient pole phase reference) An example of a relationship between the αβ fixed coordinate system, the dq synchronous coordinate system (forward mechanical salient pole phase reference, reverse mechanical salient pole phase reference) and the γδ magnetic salient pole coordinate system (forward magnetic salient pole phase reference, reverse magnetic salient pole phase reference) is diagram showing FIG. 1 is a block diagram showing the basic configuration of an electric motor drive system according to one embodiment; Block diagram showing the basic configuration of a phase determiner in one embodiment FIG. 1 is a block diagram showing the basic configuration of an electric motor drive system according to one embodiment; Block diagram showing the basic configuration of a phase determiner in one embodiment FIG. 1 is a block diagram showing the basic configuration of an electric motor drive system according to one embodiment; Block diagram showing the basic configuration of a phase determiner in one embodiment

Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 3 shows one basic structure of a drive system for a synchronous reluctance motor having dq inter-axis magnetic flux interference, especially by a drive device using the inventions of claims 1, 2, and 4. FIG. 1 is a synchronous reluctance motor, 2 is a power converter, 3 is a current detector, 4a and 4b are three-phase two-phase converters and two-phase three-phase converters, respectively, and 5a and 5b are both vector rotators. , 6 indicates a current controller, 7 a command converter, 8 a position/speed sensor, and 9 a phase determiner. In FIG. 3, devices 2 to 9, excluding the synchronous reluctance motor 1, constitute the driving device. In particular, two devices 8 and 9 constitute the coordinate system phase determining means, and six devices 2, 3, 4a, 4b, 5a, 5b, 6 and 7 constitute the stator current control means. there is In the present invention, the command converter 7, which plays the role of converting the torque command value τ* into the current command value i1* on the γδ magnetic salient pole coordinate system, is also regarded as part of the stator current control means. In addition, in this figure, the 2×1 vector signal and the 3×1 vector signal are represented by one thick signal line in order to ensure simplicity. The following block diagram representation also follows this.

The three-phase stator currents detected by the current detector 3 are converted into biaxial currents (two-phase currents) on the αβ fixed coordinate system by the three-phase to two-phase converter 4a, and then converted to γδ by the vector rotator 5a. It is converted into γ-axis current and δ-axis current of the magnetic salient pole coordinate system and sent to the current controller 6 . The current controller 6 generates biaxial voltage command values on the γδ magnetic salient polar coordinate system so that the biaxial currents on the γδ magnetic salient polar coordinate system follow the current command values of the respective axes, and sends them to the vector rotator 5b. At 5b, the biaxial voltage command values on the γδ magnetic salient pole coordinate system are converted into biaxial voltage command values on the αβ fixed coordinate system and sent to the two-to-three phase converter 4b. In 4b, the biaxial voltage command value (two-phase voltage command value) is converted into a three-phase voltage command value and output as a command value to the power converter 2. FIG. The power converter 2 generates power according to the command value and applies it to the synchronous reactance motor 1 to drive it. In FIG. 3, in order to clearly indicate the coordinate system in which voltage and current are defined, footnotes r (γδ magnetic salient pole coordinate system), s (αβ fixed coordinate system), and t (uvw coordinate system) are used to indicate these. attached.

FIG. 4 shows the inside of the phase determiner 9, which is a major component of the coordinate system phase determining means. The phase determiner 9 of FIG. 4 is constructed according to the second aspect of the invention. More specifically, it is constructed according to the formulas (1) and (13). Considering that the inductance such as the interference inductance used in the formula (1) can change according to the stator current, the phase determiner 9 in FIGS. signal lines are indicated by dashed lines. In the phase determiner 9, the coordinate system phase .theta..alpha..gamma.

The command converter 7 and current controller 6 in FIG. That is, first, the γ-axis inductance Lγ and the δ-axis inductance Lδ used for designing and configuring these devices are determined based on the equation (2) according to the fourth aspect of the invention. Next, (11 ), the design and construction of the command converter 7 and the current controller 6 are completed. A conventional design and configuration method for a synchronous reluctance motor without dq inter-axis magnetic flux interference is explained in detail in Non-Patent Document 2, so further explanation is refrained.

Next, FIG. 5 shows one basic structure of a drive system using a drive device using the inventions of claims 1, 3, and 4, especially for a synchronous reluctance motor having dq inter-axis magnetic flux interference. 5 differs from FIG. 3 in that the position/speed sensor 8 is removed in FIG. FIG. 5 shows an example in which the present invention is applied to sensorless vector control. The sensorless vector control method is roughly divided into the "driving voltage/current method" and the "high-frequency voltage application method". It can be constructed on either a salient pole coordinate system or an αβ fixed coordinate system. FIG. 5 shows a sensorless vector control system in which a phase determiner is configured on a γδ magnetic salient pole coordinate system based on the driving voltage and current utilization method.

FIG. 6 shows the internal structure of the phase determiner 9 in FIG. This device comprises a cosine sine signal generator 9a, a phase deviation estimator 9b and a phase synchronizer 9c. The phase deviation estimator 9b and phase synchronizer 9c in FIG. That is, first, the γ-axis inductance Lγ and the δ-axis inductance Lδ used for designing and configuring these devices are determined based on the equation (2) according to the fourth aspect of the invention. Next, in the conventional phase deviation estimator and phase synchronizer design and configuration method (design and configuration method for a synchronous reluctance motor without dq inter-axis magnetic flux interference (in other words, ideal)) ( 11) By applying the formal substitution of the equation, the design and configuration of the phase deviation estimator 9b and the phase synchronizer 9c are completed. A conventional design and configuration method for a synchronous reluctance motor without dq inter-axis magnetic flux interference is explained in detail in Non-Patent Document 2, so further explanation is refrained. Note that ωγ in FIG. 6 is the speed in the γδ magnetic salient pole coordinate system, and ω2n̂ is the estimated value of the rotor electrical speed. When the phase θαγ of the γδ magnetic salient polar coordinate system is presumptively determined according to the invention of claim 2, the speed of the γδ magnetic salient polar coordinate system is not always equal to the rotor electric speed. In the case of sensorless drive, the true value of the rotor electrical speed is unknown, so the estimated value ω2n^ is used instead of the true value ω2n.

Next, FIG. 7 shows one basic structure of a drive system using a drive device using the inventions of claims 1, 3, and 4, especially for a synchronous reluctance motor having dq inter-axis magnetic flux interference. Similar to FIG. 5, FIG. 7 shows a sensorless vector control system in which the phase determiner 9 is configured based on the driving voltage/current utilization method. However, unlike FIG. 5, the phase determiner 9 is configured on the αβ fixed coordinate system.

FIG. 8 shows the internal structure of the phase determiner 9 in FIG. This device comprises a cosine sine signal generator 9a, a phase estimator 9d and a speed estimator 9e. The phase estimator 9d and the speed estimator 9e in FIG. 8 may be configured according to the fourth aspect of the invention. That is, first, the γ-axis inductance Lγ and the δ-axis inductance Lδ used for designing and configuring these devices are determined based on the equation (2) according to the fourth aspect of the invention. Next, in the conventional phase deviation estimator and speed estimator design and configuration method (design and configuration method for a synchronous reluctance motor without dq inter-axis magnetic flux interference (in other words, ideal)) ( 11) By applying the formal substitution of the equation, the design and configuration of the phase estimator 9d and the speed estimator 9e are completed. A conventional design and configuration method for a synchronous reluctance motor without dq inter-axis magnetic flux interference is explained in detail in Non-Patent Document 2, so further explanation is refrained.

The embodiments shown using FIGS. 5 to 8 are examples in which the inventions of claims 1, 3, and 4 are applied to a sensorless vector control system based on the driving voltage/current utilization method. It should be pointed out that the inventions of claims 1, 3, and 4 can also be applied to a sensorless vector control system based on a high-frequency voltage application method. The procedure for using the conventional method for designing and configuring the phase determiner in this case is the same as the procedure for using the embodiment shown using FIGS. It should be noted that the high-frequency voltage application method is often insensitive to changes in the stator inductance. Such a high-frequency voltage application method is applied to a synchronous reluctance motor with dq inter-axis magnetic flux interference without special modification. In this case, the presumptively determined phase is the phase θαγ of the γδ magnetic salient polar coordinate system. The inventions of claims 1 and 3 do not exclude such embodiments using the high-frequency voltage application method.

The present invention of claims 1 to 4 can be widely applied to a drive device for a synchronous reluctance motor having dq inter-axis magnetic flux interference, and the scope of application of the present invention is limited to Examples 1 to 4. I would like to point out that it is not.

The invention is particularly suitable for drives for synchronous reluctance motors with dq inter-axis flux interference.

1 synchronous reluctance motor 2 power converter 3 current detector 4a 3-phase 2-phase converter 4b 2-phase 3-phase converter 5a vector rotator 5b vector rotator 6 current controller 7 command converter 8 position/speed sensor 9 phase determination device 9a cosine sine signal generator 9b phase deviation estimator 9c phase synchronizer 9d phase estimator 9e speed estimator

Claims (4)

Consists of two orthogonal axes: the d-axis (basic axis) whose axis phase is the phase of forward mechanical salient poles or reverse mechanical salient poles determined by the mechanical structure of the rotor, and the q-axis (secondary axis) orthogonal to the d-axis. A drive for a synchronous reluctance motor having inter-axis flux interference between the d-axis and the q-axis on a dq synchronous coordinate system defined by
The γδ magnetic salient polar coordinate system is a coordinate system consisting of two orthogonal axes, the γ axis (basic axis) and the δ axis (secondary axis), in which the interaxial magnetic flux interference is reduced in a state similar to extinction between the γ axis and the δ axis. defined, and the phase evaluated from the stator reference position in the γδ magnetic salient pole coordinate system is θαγ,
A synchronous reluctance characterized by comprising coordinate system phase determining means for determining a phase θαγ of a γδ magnetic salient polar coordinate system and stator current control means for performing at least a part of stator current control on the γδ magnetic salient polar coordinate system. Drive for electric motors. The d-axis inductance and the q-axis inductance of the synchronous reluctance motor on the dq synchronous coordinate system are Ld and Lq, respectively. When the phase difference between the d-axis and the γ-axis with respect to the axis is θγ,
The phase difference θγ is given by the following formula

2. A driving device for a synchronous reluctance motor according to claim 1, wherein said coordinate system phase determining means is constructed so as to substantially satisfy The coordinate system phase determining means is configured to presumptively determine the phase θαγ of the γδ magnetic salient pole coordinate system using the equivalent value of at least one of the stator voltage and stator current of the synchronous reluctance motor. A drive for a synchronous reluctance motor according to claim 1, characterized in that: The d-axis inductance and the q-axis inductance of the synchronous reluctance motor on the dq synchronous coordinate system are Ld and Lq, respectively. When the γ-axis inductance and the δ-axis inductance used for the design or configuration of the means of the driving device are Lγ and Lδ, respectively,
the following formula

Lγ and Lδ are determined so as to substantially satisfy the above, and using the determined Lγ and Lδ or the processed values, at least one of the coordinate system phase determination means and the stator current control means on the γδ magnetic salient pole coordinate system 2. A drive for a synchronous reluctance motor according to claim 1, characterized in that it is designed or constructed with means for:

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