JP7256349B2 - Synchronous motor drive controller - Google Patents

Description

The present invention relates to a drive control device for a synchronous motor. In particular, the object of the present invention is to provide a drive control device for a synchronous motor capable of suppressing torque ripples of the 6th order, 12th order, etc., which cannot be suppressed by a basic drive control device.

In the present invention, the d-axis initial current command value, compensation current command value, and final current command value are also referred to as d-axis initial current command value, d-axis compensation current command value, and d-axis final current command value, respectively. Similarly, the q-axis initial current command value, compensation current command value, and final current command value are also referred to as q-axis initial current command value, q-axis compensation current command value, and q-axis final current command value, respectively. Further, regarding various current command values, when it is not particularly necessary to distinguish between the d-axis and the q-axis, they are simply referred to as the initial current command value, compensation current command value, and final current command value. The command value is indicated by adding a prefix "*" to the symbol.

In the present invention, physical quantities, signals, etc. belonging to the d-axis and the q-axis are indicated by adding footnotes "d" and "q" respectively to the symbols.

In the present invention, the initial current command value and the compensating current command value are indicated with footmarks "f" and "h", respectively, to clearly indicate "initial" and "compensation". This type of footnote is not added to the final current command value.

３電流指令値の関係表現は、簡単な（１ｃ）式を利用して、一般性を失うことはない。これは、（１ａ）式、（１ｂ）式、（１ｃ）式の各々に用いた異なる３種の補償電流指令値の相互関係を示した次式より自明である。

本発明では、初期電流指令値、補償電流指令値、最終電流指令値の表現として、一般性を失うことなく、（１ｃ）式の和表現を用いて、本発明の詳細を説明する。The relationship between the initial current command value, compensation current command value, and final current command value is generally expressed by a function (see formula (1a)). Simply, product expression (see formula (1b)) and sum expression (see formula (1c)) are possible.
This is shown in the following equation (1) using initial, compensation, and final three current command values on the q-axis.

The relational expression of the three current command values utilizes a simple formula (1c) without loss of generality. This is self-evident from the following equation showing the interrelationship between the three different compensating current command values used in each of equations (1a), (1b) and (1c).

In the present invention, as expressions of the initial current command value, the compensation current command value, and the final current command value, the sum expression of the equation (1c) is used without loss of generality to describe the details of the present invention.

In the present invention, a synchronous motor with different d-axis inductance and q-axis inductance is called a salient pole synchronous motor, and a synchronous motor with the same inductance on both axes is called a non-salient pole synchronous motor.

High-performance control of synchronous motors can be achieved by so-called vector control methods. In basic vector control, even if the power converter has ideal characteristics, the generated torque is periodic depending on the rotation speed due to the spatial distortion characteristics of the synchronous motor represented by the non-sinusoidal induced voltage. It has a ripple (pulsation).

Compensation for the ripple contained in the generated torque is traditionally made by superimposing an appropriate compensating current command value on the initial current command value corresponding to the initial torque command value. According to this, effective compensation can be expected when the current control system has a corresponding ability to follow the compensating current command value. For reference, FIG. 5 shows a torque ripple compensation method (that is, an example of a compensation method in which a compensation current command value is superimposed on an initial current command value) used in Patent Document (1) listed below. Similarly, the torque ripple compensation method used in Patent Document (2) (that is, the initial torque command value (substantially equivalent to the initial current command value) is superimposed on the compensation torque command value (substantially equivalent to the compensation current command value) 1 compensation method example) is shown in FIG.

As illustrated in FIGS. 5 and 6 of the preceding invention, compensation of the initial current command value by the compensating current command value is performed only with respect to the q-axis. In the case of a non-salient pole synchronous motor, the d-axis current is generally controlled to zero, so the above prior art can achieve the desired torque ripple suppression. However, in the case of a salient pole type synchronous motor, it is not possible to obtain the desired torque ripple suppression. A salient pole synchronous motor can generate reluctance torque in addition to magnet torque. In drive control of a salient pole synchronous motor, the d-axis current is generally controlled to be non-zero in order to achieve high-efficiency drive by simultaneous generation of both torques. The non-zero d-axis current and q-axis compensation current (response value of the q-axis compensation current command value) newly generate ripple-like reluctance torque according to the ripple frequency of the q-axis compensation current. As a result, the desired torque ripple suppression performance cannot be obtained for the generated torque as a whole including the magnet torque and the reluctance torque. The reduction in torque ripple suppression performance becomes more severe as the saliency becomes stronger, and is eventually lost.

Kazuo Shimane: "Elevator Control Device", Unexamined Patent Publication, Japanese Unexamined Patent Publication No. 2001-31339 (1999-7-27) Shinji Shinnaka: “Drive Control Device for Synchronous Motor”, Unexamined Patent Publication, JP 2012-100510 (2010-10-31)

Shingo Sekino and Shinji Shinnaka: "Simple High-Quality Torque Control for PMSM, Compensation for Torque Ripple Caused by Induced Voltage Distortion", IEEJ Transactions D, Vol. 136, No. 10, pp. 819-828 (2016-10)

The present invention has been made under the above background, and its objects are as follows.
1) To provide a drive control device having a torque ripple suppression function that can be applied to a salient pole synchronous motor assuming non-zero control of the d-axis current.
2) To provide a drive control device in which a torque ripple suppression method for a synchronous motor assuming d-axis current zero control can also be applied to a salient pole synchronous motor with d-axis current non-zero control.
3) To provide a drive control device that achieves the functions and performances described in the above 1) and 2) without using a large computational load.

次の条件式を実質的に満たすように、

補償電流指令値を生成するように該補償電流指令値生成手段を構成したことを特徴とする。In order to achieve the above object, the invention of claim 1 captures the stator current as a vector signal on a dq synchronous coordinate system consisting of orthogonal d-axes and q-axes with the rotor north pole phase as the d-axis phase, Current to be controlled to follow both the initial current command value and the compensation current command value, or to follow the final current command value including both the initial current command value and the compensation current command value A drive control device for a synchronous motor, comprising at least control means and compensation current command value generating means for generating a compensation current command value for compensating an initial current command value, wherein the initial current command value of the d-axis, the compensation The current command value and final current command value are expressed by idf*, idh* and id*, respectively, and the q-axis initial current command value, compensation current command value and final current command value are respectively expressed by iqf*, iqh* and iq*. and define the interrelationship among the initial current command value, compensation current command value, and final current command value by the following additive formula:

In order to substantially satisfy the following conditional expression,

The compensating current command value generating means is configured to generate the compensating current command value.

The invention of claim 2 is the drive control device for a synchronous motor of claim 1, wherein the compensation current command value generating means first generates the q-axis compensation current command value iqh*, and then generates The q-axis compensation current command value is used to generate the d-axis compensation current command value idh* so as to substantially satisfy the conditional expression (ie, equation (4)).

ここに、Ｎｐ、Ｌｄ、Ｌｑは各々極対数、ｄ軸インダクタンス、ｑ軸インダクタンスである。また、ｉｄ、ｉｑは各々ｄ軸電流、ｑ軸電流である。ｄ軸電流、ｑ軸電流は、各々、ｄ軸最終電流指令値の応答値、ｑ軸最終電流指令値の応答値でもある。The effect of the invention of claim 1 will be described. In describing the effects, it is assumed that "the driving device for the synchronous motor is already configured with a current control system having high follow-up performance". That is, it is assumed that "currents that are the same response value to the current command value are substantially the same." A salient pole synchronous motor generates reluctance torque in addition to magnet torque. A formula for generating the reluctance torque τr is given by the following formula.

Here, Np, Ld, and Lq are the number of pole pairs, d-axis inductance, and q-axis inductance, respectively. Also, id and iq are d-axis current and q-axis current, respectively. The d-axis current and the q-axis current are also the response values of the d-axis final current command value and the q-axis final current command value, respectively.

突極形同期電動機の駆動制御においては、一般に、リラクタンストルクを活用した効率駆動を達成すべく、ｄ軸電流は非ゼロに制御される。非ゼロのｄ軸電流とｑ軸補償電流（ｑ軸補償電流指令値の応答値）とは、一般に、ｑ軸補償電流のリプル周波数に応じたリプル状のリラクタンストルクを新たに発生する。以上は、一般論である。ところが、上の（６）式は、請求項１の発明に従うならば、「突極形同期電動機のｄ軸電流を非ゼロに制御する場合にも、同電動機が発生するリラクタンストルクは、リプルを有するｑ軸電流の影響を受けず、さらには、発生リラクタンストルクは、リプルを有しない初期電流指令値に従った発生リラクタンストルクと同様となる」という効果が得られることを示している。ひいては、請求項１の発明に従えば、「ｄ軸電流の非ゼロ制御を想定した突極形同期電動機に適用可能な、トルクリプル抑圧機能を備えた駆動制御装置が実現できるようになる」という効果が得られる。The formula (3) in the invention of claim 1 defines the interrelationship among the initial current command value, compensation current command value, and final current command value. The same expression indicates that the relational expression of the initial current command value, the compensation current command value, and the final current command value is based on the sum expression of the formula (1c). Under the premise that "the currents that are the same response value to the current command value are substantially the same", the formula (5) follows the formulas (3) and (4) according to the invention of claim 1, then the following formula It is expanded and organized as follows.

In drive control of a salient pole synchronous motor, generally, the d-axis current is controlled to be non-zero in order to achieve efficient drive utilizing reluctance torque. The non-zero d-axis current and q-axis compensation current (response value of the q-axis compensation current command value) generally newly generate ripple-like reluctance torque according to the ripple frequency of the q-axis compensation current. The above is a generalization. However, according to the first aspect of the invention, the above equation (6) is such that even when the d-axis current of a salient pole synchronous motor is controlled to be non-zero, the reluctance torque generated by the motor does not generate ripples. In addition, the generated reluctance torque is similar to the generated reluctance torque according to the initial current command value without ripple. Furthermore, according to the invention of claim 1, it is possible to realize a drive control device having a torque ripple suppression function that can be applied to a salient pole synchronous motor assuming non-zero control of the d-axis current. is obtained.

The effect of the invention of claim 2 will be described. In non-salient pole synchronous motors, the d-axis current is generally controlled to zero from the viewpoint of driving efficiency. Therefore, generation of the q-axis compensation current command value iqh* is important and essential in the torque ripple suppression method assuming a non-salient pole synchronous motor (see Patent Documents 1 and 2). According to the second aspect of the invention, the q-axis compensation current command value iqh* is first generated, and then the generated q-axis compensation current command value is used to substantially satisfy the conditional expression (4). It becomes possible to generate the d-axis compensation current command value idh*. If the invention of claim 2 is utilized, this fact can be obtained from the torque ripple suppression method showing the generation of the q-axis compensation current command value iqh* under the condition of "zero control of the d-axis current". It means that the effect of being able to remove the condition of "zero control" can be obtained. Furthermore, if the invention of claim 2 is used, the torque ripple suppression method assuming a non-salient pole synchronous motor can be applied to a salient pole synchronous motor with non-zero control of the d-axis current in pursuit of efficient driving. The effect of becoming is obtained.

The conditional expression (4) used in the inventions of claims 1 and 2 is simple, with one division and one multiplication. Furthermore, according to the inventions of claims 1 and 2, it is possible to obtain the effect of the invention with a simple calculation.

"Block diagram showing basic configuration of drive control device in one embodiment" "Block diagram showing basic configuration of second compensation current command value generator in one embodiment" "Block diagram showing basic configuration of second compensation current command value generator in one embodiment" "Block diagram showing basic configuration of drive control device in one embodiment" "Block diagram showing the basic configuration of a conventional single-drive control device" "Block diagram showing the basic configuration of a conventional single-drive control device"

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example in which the drive control device of the present invention is applied to a synchronous motor. 1 is a synchronous 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, 5a and 5b are both vector rotators, 6 is a high-following current controller, 7 is a phase detector, 8 is a speed detector, 9 is a cosine sine signal generator, 10 is a command converter, and 11 is a compensation current command value using the present invention. Generators (implementing compensation current command value generating means) are shown respectively. In FIG. 1, devices 2 to 11, excluding the motor 1, constitute a drive control device.

In this figure, a 3×1 or 2×1 vector signal is represented by one thick signal line in order to ensure simplicity. The following block diagram representation also follows this. In this figure, when the stator current and the stator voltage are expressed in vectors, footmarks "1" are added to the symbols to indicate that these are physical quantities on the stator side. In addition, in order to clarify the coordinate system in which the stator current and stator voltage, which are vector signals, are defined, the symbols indicating these vector signals are added with footnotes r (dq synchronous coordinate system), s (αβ fixed coordinate system), t (uvw coordinate system) is attached. Similarly, the rotor electric speed ω2n, which is a physical quantity on the rotor side, is given a footnote “2” to indicate that it is a physical quantity on the rotor side.

The three-phase stator currents detected by the current detector 3 are converted into two-phase currents on the αβ fixed coordinate system by the three-phase to two-phase converter 4a, and then converted to two-phase currents on the dq synchronous coordinate system by the vector rotator 5a. It is converted into phase currents (d-axis current, q-axis current). The converted current is converted into a control deviation from the same command value (that is, the final current command value) and sent to the high follow-up current controller 6 . The high-following current controller 6 adjusts the two-phase current on the dq synchronous coordinate system so that the control deviation becomes zero, in other words, the final current command value i1* (in FIG. A two-phase voltage command value on the dq synchronous coordinate system is generated so as to follow the above equation (7). The two-phase voltage command values on the dq synchronous coordinate system are sent to the vector rotator 5b. At 5b, the voltage command values on the dq synchronous coordinate system are converted into two-phase voltage command values on the αβ fixed coordinate system and sent to the two-to-three phase converter 4b. In 4b, the 2-phase voltage command value is converted into a 3-phase voltage command value and output to the power converter 2 as the voltage command value. The power converter 2 generates a voltage corresponding to the three-phase voltage command value and applies it to the synchronous motor 1 to drive it.

The command converter 10 in the embodiment of FIG. 1 receives the initial torque command value τf as an input signal, and the initial current command value i1f* of the d-axis and the q-axis (in FIG. ) is generated and output. The initial current command value i1f* and the d-axis and q-axis compensation current command values i1h* output from the compensation current command value generator 11 (vector representation in FIG. 1, see equation (7) below) are added , and the final current command value i1* (vector notation in FIG. 1, see formula (7) below) for the d-axis and the q-axis is synthesized. Vector notation of various current command values is exactly as shown in the following equation (7).

As is clear from the above description, in the drive control device composed of the devices 2 to 11, the devices 2 to 9 are configured to set the stator current in quadrature with the rotor north pole phase as the d-axis phase. A current control means for capturing as a vector signal on a dq synchronous coordinate system consisting of d-axis and q-axis, and controlling to follow the final current command value including both the initial current command value and the compensation current command value. Realized. Further, the compensation current command value generator 11 implements "compensation current command value generating means for generating a compensation current command value for compensating the initial current command value".

The core of the present invention lies in the compensating current command value generator 11, which is one of the components of the drive control device. An embodiment of the compensation current command value generator 11 will be described. In particular, an embodiment of the compensating current command value generator 11 configured based on the inventions of claims 1 and 2 will be described. In the embodiment of FIG. 1, as clearly shown in the figure, the compensating current command value generator 11 is composed of a series combination of a first compensating current command value generator 11a and a second compensating current command value generator 11b. It is In this embodiment, the first compensation current command value generator 11a uses the stator current information (detected value), the stator voltage information (voltage command value), and the rotor electrical speed information (detected value) to generate q A shaft compensation current command value iqh* is generated. The first compensation current command value generator 11a that performs such generation of the q-axis compensation current command value iqh* can be easily implemented according to the invention of Patent Document 2, for example.

The q-axis compensation current command value iqh* generated by the first compensation current command value generator 11a is sent to the second compensation current command value generator 11b. The second compensation current command value generator 11b uses the q-axis compensation current command value iqh* and the initial current command values for the d-axis and q-axis to output final compensation current command values for the d-axis and q-axis. there is FIG. 2 shows an example of the second compensation current command value generator 11b configured based on the formula (4). As is clear from the figure, the second compensation current command value generator 11b is constructed according to the first and second inventions. That is, the present device is constructed so as to accurately satisfy the first and second expressions of the expression (4), which are the conditional expressions according to the present invention.

（８）式に基づき構成された第２補償電流指令値生成器１１ｂの１例を図３に示した。The second compensation current command value generator 11b may substantially satisfy the conditional expression (4) according to the present invention. ) can be constructed using the formula

FIG. 3 shows an example of the second compensation current command value generator 11b configured based on the formula (8).

なお、第１高追従電流制御器６ａと第１高追従電流制御器６ｂの構成法の詳細は、非特許文献１に詳しく解説されているので、これ以上の説明は省略する。A third embodiment is shown. FIG. 4 shows an example in which the drive control device of the present invention is applied to a synchronous motor. The notation rule represented by the vector notation of voltage and current is the same as in FIG. In the drive control device of FIG. 4, devices using the same device names as in FIG. 1 are the same as in FIG. Therefore, description of these devices is omitted. The major difference between FIG. 4 and FIG. 1 of this embodiment lies in the high-following current controller and the compensation current generator. In FIG. 4, the high-following current control function is configured using a first high-following current controller 6a and a first high-following current controller 6b. The first high follow-up current controller 6a is a current controller mainly for obtaining a follow-up function to the initial current command value. Instead, the second high follow-up current controller 6b is a current controller mainly for obtaining a follow-up function to the compensating current command value. That is, the drive control device shown in FIG. A current control means is realized which catches the current as a vector signal on the system and performs control so as to follow both the initial current command value and the compensation current command value. It should be noted that the drive control device of FIG. 4 differs from the drive control device of FIG. 1 in the input terminal for the compensation current command value to the current control loop. In particular, the input signal (current control deviation) to the first high-following current controller 6a is synthesized according to the right side of the following equation (9) based on equation (3).

The details of the configuration of the first high-following current controller 6a and the first high-following current controller 6b are explained in detail in Non-Patent Document 1, so further explanation will be omitted.

The heart of the present invention lies in a compensating current command value generator (implementing compensating current command value generating means) 11, which is one of the components of the drive control device. An embodiment of the compensation current command value generator 11 will be described. That is, an embodiment of the compensating current command value generator 11 configured based on the inventions of claims 1 and 2 will be described. In the embodiment of FIG. 4, as clearly shown in the figure, the compensating current command value generator 11 is composed of a series combination of a first compensating current command value generator 11a and a second compensating current command value generator 11b. It is In this embodiment, the first compensating current command value generator 11a generates two signals of an initial current command value i1f* (vector quantity, initial current command values of d-axis and q-axis) and rotor phase (electrical phase) θα. is used to generate the q-axis compensation current command value iqh*. The first compensation current command value generator 11a that performs such generation of the q-axis compensation current command value iqh* can be easily implemented according to the invention of Non-Patent Document 1, for example.

The q-axis compensation current command value iqh* generated by the first compensation current command value generator 11a is sent to the second compensation current command value generator 11b. The second compensation current command value generator 11b uses the q-axis compensation current command value iqh* and the initial current command values for the d-axis and q-axis to output final compensation current command values for the d-axis and q-axis. there is An example of the configuration of the second compensation current command value generator 11b is shown in FIG. (4) which approximately satisfies the formula).

In the embodiment using FIGS. 1 and 4, the current control means is implemented as a feedback current control system. It should be pointed out that the current control means to which the invention applies is not limited to a feedback current control system. More specifically, it is pointed out that the current control means may be implemented wholly or partly as a feedforward current control system.

In the embodiment using FIGS. 1 to 4, both the inventions of claim 1 and claim 2 are used. It should be pointed out that the compensating current command value generating means (compensating current command value generator) can also be realized using only the first invention. The compensating current command value generator according to this implementation is generally not a series combination of the first compensating current command value generator and the second compensating current command value generator illustrated in FIGS. A command value and a q-axis compensation current command value are generated in parallel. It should be pointed out that the present invention does not exclude compensation current command value generators that perform such parallel generation.

As an example of generating a compensating current command value that substantially satisfies the conditional expression (that is, expression (4)) of the present invention, the example of FIG. 2 that exactly satisfies expression (4) is shown. As an example of generation of the compensation current command value that substantially satisfies the expression (4), the generation example of FIG. 3 based on the expression (8), which is an approximation of the expression (4), is shown. It should be pointed out that the generation of the compensation current command value that substantially satisfies the equation (4) is not limited to the embodiments of FIGS. It should be pointed out that there are various approximation formulas for formula (4).

INDUSTRIAL APPLICABILITY The present invention is particularly suitable for applications that require high efficiency and high quality torque generation among applications using salient pole synchronous motors.

1 synchronous 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 high-following current controller 6a first high-following current controller 6b second High follow-up current controller 7 Phase detector 8 Speed detector 9 Cosine sine signal generator 10 Command converter 11 Compensation current command value generator 11a First compensation current command value generator 11b Second compensation current command value generator

Claims (2)

The stator current is captured as a vector signal on a dq synchronous coordinate system consisting of orthogonal d-axes and q-axes with the rotor north pole phase as the d-axis phase. current control means for controlling to follow or to follow a final current command value including both the initial current command value and the compensation current command value;
A drive control device for a synchronous motor, comprising at least compensating current command value generating means for generating a compensating current command value for compensating the initial current command value,
The d-axis initial current command value, compensation current command value, and final current command value are represented by idf*, idh*, and id*, respectively, and the q-axis initial current command value, compensation current command value, and final current command value are respectively When expressed by iqf*, iqh*, iq* and the mutual relationship between the initial current command value, compensation current command value, and final current command value is defined by the following additive formula,

In order to substantially satisfy the following conditional expression,

A drive control device for a synchronous motor, wherein said compensating current command value generating means is configured to generate a compensating current command value. The compensation current command value generation means first generates a q-axis compensation current command value iqh*, and then uses the generated q-axis compensation current command value to substantially satisfy the conditional expression for the d-axis 2. A drive control device for a synchronous motor according to claim 1, wherein said device is configured to generate a compensation current command value idh*.

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