JP2904210B1 - Motor control device and method, and hybrid vehicle - Google Patents

Abstract

Abstract: A torque ripple is caused by a sensorless air angle detection error and a current control error of a synchronous motor. For a synchronous motor, a step of applying a voltage assuming an electrical angle of a rotor, a step of calculating a voltage equation based on a current flowing according to the voltage, and correcting an electrical angle based on an error generated in a calculation result. An electrical angle is detected by a process without a sensor. In addition, torque is generated by applying a voltage according to the electrical angle and causing a torque current to flow. At this time, the relationship between the electrical angle and the inductance of the motor winding is stored in advance as a table, and the inductance corresponding to each electrical angle is used with reference to the table. Further, the detection of the electrical angle and the control of the torque current are performed in consideration of the voltage generated by the change in the inductance accompanying the rotation of the motor. By these means, the torque ripple of the synchronous motor can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for operating a so-called salient-pole synchronous motor while suppressing torque fluctuation, and a hybrid vehicle equipped with a synchronous motor driven by such control.

[0002]

2. Description of the Related Art In recent years, a synchronous motor and a motor have been mounted,
Various hybrid vehicles capable of running at least by the power of a synchronous motor have been proposed. A synchronous motor mounted on such a hybrid vehicle is a synchronous motor that causes a polyphase alternating current to flow through a winding and rotates a rotor by an interaction between a magnetic field generated by the winding and a magnetic field generated by a permanent magnet. In order to obtain a desired rotational torque by such a motor, it is necessary to control the polyphase alternating current flowing through the winding according to the position of the rotor, that is, the electrical angle.

As a method of detecting an electrical angle, a method of detecting an electrical angle using a sensor such as a Hall element is generally used. On the other hand, for a salient-pole type synchronous motor, a method of detecting an electrical angle without using the above-described sensor without using the sensor has been proposed from the viewpoint of ensuring control reliability.

As a method of detecting the electric angle of a salient pole type synchronous motor without a sensor, particularly when the motor is operating at a relatively high speed (hereinafter simply referred to as high speed operation),
A method using a voltage equation represented by the following equations (1) and (2) has been proposed. Vd−R · Id−p (Ld · Id) + ω · Lq · Iq = 0 (1) Vq−R · Iq−p (Lq · Iq) −ω · Ld · Id−ωφ = 0 (2) Here, V is a voltage value applied to the motor, I is a current value flowing through the motor winding, and L is an inductance of the winding. The suffixes d and q attached to V, I and L mean that the respective values are values in the so-called d-axis and q-axis directions of the motor. For the other variables in the above equation, R is the motor coil resistance, ω is the electric rotational angular velocity of the motor, φ
Indicates the number of magnetic fluxes determined by the permanent magnet of the motor. The electric angular velocity ω of the motor is a value obtained by multiplying the mechanical angular velocity of the motor by the number of pole pairs. Among these quantities, the motor coil resistance R, the inductance L, and the number of magnetic flux crossings φ are values unique to the motor, and thus may be collectively referred to as a motor constant. P is a time differential operator. That is, p (Ld · Id) = d (Ld · Id) / dt.

[0005] The d-axis and the q-axis will be briefly described with reference to FIG. The permanent magnet type three-phase synchronous motor is represented by an equivalent circuit shown in FIG. In this equivalent circuit, a direction passing through the rotation center of the motor and along the magnetic field generated by the permanent magnet is generally called a d-axis. On the other hand, a direction orthogonal to the d-axis in the rotation plane of the rotor is generally called a q-axis. In the equivalent circuit of FIG. 4, the angle between the U-phase and the d-axis is the electric angle θ of the motor.
Is equivalent to

The above-mentioned voltage equations (1) and (2) are d-axis,
The equation always holds for the q axis. When controlling the motor without a sensor, the motor controller first calculates the above equation based on a certain assumed electrical angle (corresponding to θc in FIG. 4). At this time, the calculation result has a calculation error corresponding to the error angle (△ θ in FIG. 4) between the assumed electrical angle θc and the actual electrical angle θ. That is, using the detected current and voltage values, the above voltage equation (1)
If (2) is calculated, both equations that should have a value of 0 have non-zero values. Since this error occurs according to the error angle, the magnitude of the error angle can be determined based on the error. By sequentially correcting the assumed electrical angle θc according to the error angle thus obtained, the electrical angle can be detected without a sensor.

On the other hand, after the electrical angle is determined, it is necessary to control the polyphase alternating current flowing through the windings according to the electrical angle in order to obtain a desired rotational torque by the motor. This current control is performed as follows irrespective of whether or not the electrical angle is detected using the sensor. First, current command values id * and iq * in the d-axis and q-axis directions according to the torque to be output by the synchronous motor and the rotation speed are set. When the synchronous motor is rotating, since the currents id and iq have already flowed in the d-axis and q-axis directions, the currents id and iq and the current command values id * and
A voltage value to be applied in the d-axis and q-axis directions is calculated by proportional-integral control (hereinafter referred to as PI control) based on the difference from iq *. That is, the voltage value is set based on a term obtained by multiplying the difference by a gain and an integral term of the difference. The voltage value to be applied to each phase of the synchronous motor is set based on the voltage value set in this way.

[0008]

However, in the above-described method of controlling a synchronous motor, the rotational torque of the motor pulsates,
It has been found that so-called torque ripple occurs. Such pulsation impairs the stability of the operation of the device using the synchronous motor and causes noise and vibration. Also, the operating efficiency of the synchronous motor is reduced.

For example, when a synchronous motor is mounted on a hybrid vehicle, if such a torque ripple occurs, the riding comfort of the hybrid vehicle is impaired. Also,
The reduction in the operating efficiency of the synchronous motor based on the torque ripple also reduces the advantage of the hybrid vehicle which is said to be excellent in fuel consumption.

One of the causes of the occurrence of torque ripple is an error in detecting an electrical angle without a sensor.
Even if the electrical angle is detected using a sensor,
Since slight occurrence of torque ripple has occurred, it has been suggested that the occurrence of torque ripple is also caused by current control itself. The cause of the current control could not be elucidated.

A first object of the present invention is to provide a technique for accurately detecting an electrical angle when a salient-pole synchronous motor is controlled sensorlessly. A second object is to reduce torque ripple of the synchronous motor by performing appropriate current control regardless of the presence or absence of a sensor. Furthermore, the third is to provide a hybrid vehicle to which such technology is applied.
The purpose of.

[0012]

Means for Solving the Problems and Their Functions / Effects In order to solve at least a part of the above problems, the present invention has the following constitution. According to a first motor control device of the present invention, for a synchronous motor having a winding and a rotor through which a polyphase alternating current can flow, an electrical angle estimating unit for assuming an electrical angle of the rotor and an output of the synchronous motor are provided. Voltage applying means for applying a voltage corresponding to the power torque to the winding based on the assumed electrical angle, at least a voltage value of the voltage applied by the voltage applying means, and By performing a predetermined calculation using a current value flowing through the winding and an inductance determined according to the characteristics of the motor,
Electric angle correction means for correcting the assumed electric angle, and a motor control for controlling the operation of the synchronous motor by reflecting the corrected electric angle on the electric angle assumption by the electric angle estimation means. The device, further comprising a storage unit in which a relationship between the electrical angle of the rotor and the inductance is stored in advance, wherein the electrical angle correction unit, based on the electrical angle assumed in the predetermined calculation, The gist is to use the inductance obtained by referring to the relationship stored in the storage means.

A first synchronous motor control method according to the present invention is as follows.
(A) assuming an electrical angle of the rotor for a synchronous motor having a winding and a rotor through which a polyphase alternating current can flow;
(B) applying a voltage corresponding to the torque to be output by the synchronous motor to the winding based on the assumed electric angle; and (c) applying at least the voltage applied in the step (b). Correcting the assumed electrical angle by performing a predetermined calculation using a voltage value of the current, a current value flowing through the winding according to the voltage, and an inductance determined according to characteristics of the motor. A control method for controlling the operation of the synchronous motor by reflecting the corrected electrical angle on the assumption of the electrical angle by the electrical angle estimation means, further comprising: (d) Calculating an inductance corresponding to the electrical angle by referring to a relationship stored in advance between the electrical angle and the inductance based on the assumed electrical angle; The inductance used in, and summarized in that an inductance which is calculated in the step (d).

According to the motor control device or the motor control method, when the operation of the synchronous motor is controlled without a sensor, the electrical angle thereof can be accurately detected. As a result, the operation of the synchronous motor can be appropriately controlled, and the torque ripple generated in the synchronous motor can be reduced. Hereinafter, the operation will be described.

In order to make the above invention, it is first necessary to clarify the reason why the conventional electrical angle detecting method has failed to accurately detect the electrical angle. Since research on the technology of controlling a synchronous motor without a sensor has been started in recent years, there is no example in which the cause of the occurrence of an electrical angle detection error is sufficiently clarified, and there is no report on a means for eliminating the cause. Then, the inventor of the present application first clarified based on various experiments and analyzes that the cause of the occurrence of the electrical angle detection error is as follows.

The conventional electrical angle detecting method calculates the above-described voltage equations (1) and (2) based on a certain assumed electrical angle (corresponding to θc in FIG. 4), and a calculation error generated at that time. Is corrected according to the equation (1), and the actual electrical angle is obtained. The calculation error is obtained by replacing the time derivative (d / dt) with a time difference (amount of change / time), and then transforming the voltage equation into the following equation (3).
Obtained as (5). ΔId = Id (n) −Id (n−1) −t (Vd−RId + ωLqIq) / Ld (3) ΔIq = Iq (n) −Iq (n−1) −t (Vq−RIq− ωLdId−E (n−1)) / Lq (4) E (n) = E (n−1) −K1 △ Iq (5)

Here, Id and Iq indicate currents on the d-axis and the q-axis, respectively.
The above calculation is performed based on the fact that the calculation is periodically and repeatedly performed, and (n) is a value at the present time, and (n)
-1) means the value at the time when the above calculation was performed last time. That is, the portion of Id (n) -Id (n-1) represents the amount of change in the current Id from the time when the motor control was last executed to the time this time. It should be noted that the cycle at which this calculation is performed is the time t
It is.

Further, the term of the time derivative in the above voltage equation is developed on the assumption that the inductance takes a constant value. For example, p (Ld · Id) = Ld · p (Id). The same applies to p (Lq · Iq).

Regarding other variables, Vd and Vq are voltage values applied to the windings, ω is the rotational angular velocity of the motor, Ld,
Lq is the inductance in the d-axis and q-axis directions. ω is r
ad / sec, and the motor rotation speed N (r
pm) and the number of pole pairs Np, ω = 2π · Np ·
There is a relationship of N / 60. K1 is E (n), E (n-
1) and △ Iq, which are used to calculate the electrical angle, which will be described later, and are experimentally determined.

The thus calculated △ Id, △ Iq, E
Using (n), the electrical angle θ (n−1) assumed based on the result of the previous electrical angle detection is corrected to a new electrical angle θ (n) based on the following equation (6). However, sgn means “+” when ω> 0 and “−” when ω <0. K2 and K3 are K
Similar to 1, the gain is used for calculating the electrical angle, and is experimentally determined. Here, since it is assumed that the motor is operating at high speed, the case where the motor is not rotating, that is, the case where ω = 0, is not considered.

As described in the above description, in the method of detecting an electric angle without a sensor, the inductance has been conventionally treated as a constant value. This is because the technology of sensorless control of a synchronous motor is in an early stage, and phenomena are simplified and modeled. This is also because the change in inductance was considered to be relatively small and negligible.

FIG. 11 shows how the inductance changes when the salient pole type synchronous motor is rotating. FIG. 11 has 12 teeth for winding the coil on the stator side,
5 is a graph showing the relationship between the d-axis and q-axis inductances Ld and Lq and the electrical angle for a salient pole type synchronous motor in which a permanent magnet is attached to a rotor. Each inductance is calculated by magnetic field analysis at each electrical angle, and the result is plotted. As shown in this graph, it was found that both the inductances Ld and Lq periodically changed according to the change in the electrical angle. In particular, it has been clarified that the inductance Lq has undergone a large change six times. The variation range obtained by subtracting the minimum value from the maximum value of the inductance Lq also corresponded to about 20% of the average value of the inductance Lq. The cycle in which the inductances Ld and Lq change depends on the number of teeth of the stator and the like.

FIG. 12 shows the result of detecting the electrical angle of the rotating synchronous motor by the conventional detection method. In FIG. 12, a graph shown by a broken line is a true value, and a graph shown by a solid line is a detection result. Electric angle from 0 degree to 3
When looking at a section that changes up to 60 degrees, for example, a section from time 0 to t1, the detected electrical angle has an error that changes periodically with respect to the true value. This error is shown in FIG.
As shown by e6, it has been clarified that the variation of the error appears in this section six times at a substantially constant cycle. This corresponds to the variation of the inductance Lq shown in FIG. That is, from the results of the analysis and the experiment, it has been clarified that the fluctuation of the inductance Lq greatly affects the detection of the electrical angle. Similarly, it was found that the fluctuation of the inductance Ld was not as large as the inductance Lq, but affected the detection of the electrical angle.

The inventor of the present application has clarified, based on the above-described experiments and analysis, that the essential cause is the above-described change in inductance, while there are many factors that can be considered for errors occurring in the detection of the electric angle of the motor. did.

Based on this cause, in the motor control apparatus and the motor control method of the present invention, the relationship between the electrical angle and the inductance of the rotor of the synchronous motor, that is, the relationship shown in FIG. The operation of the synchronous motor is controlled using the inductance according to the assumed electrical angle. As described above, by performing the control in consideration of the change in the inductance, the detection error of the electrical angle can be reduced, and the appropriate torque can be output from the motor.

The means for storing the relationship between the electrical angle and the inductance in advance can be implemented in various ways. For example, a method may be adopted in which data corresponding to the graph shown in FIG. 11 is obtained by analysis or experiment and stored in advance as a discrete table. A method of storing such data by approximating it with a function is also possible.

As shown in FIG. 11, both of the inductances Ld and Lq may be stored, or only one of them may be stored. When only one of them is stored, it is needless to say that it is preferable to store the one having a larger variation width due to the variation of the electrical angle. Also, the inductance is d-axis,
The information may be stored without being decomposed in the q-axis direction.

According to a second motor control device of the present invention, an electric angle estimating means for estimating an electric angle of a rotor is provided for a synchronous motor having a winding capable of flowing a polyphase alternating current and a rotor; Voltage applying means for applying a voltage corresponding to the torque to be output to the winding based on the assumed electrical angle, at least a voltage value of the voltage applied by the voltage applying means, An electrical angle correction means for correcting the assumed electrical angle by performing a predetermined calculation using a current value flowing through the winding and an inductance determined according to the characteristics of the motor. A motor control device that controls the operation of the synchronous motor by reflecting the corrected electrical angle on the assumption of the electrical angle by the electrical angle estimation means, further comprising: By referring to the storage means in which the relationship between the rotor and the rotor is stored in advance and the relationship stored in the storage means based on the assumed electrical angle, the electrical angle can be changed according to the rotation of the rotor. Inductance change amount calculation means for calculating the change amount of the inductance, the predetermined calculation performed by the electrical angle correction means,
The gist is that the calculation is performed in consideration of a voltage resulting from the inductance change amount calculated by the inductance change amount calculation means.

The second synchronous motor control method of the present invention is as follows.
(A) assuming an electrical angle of the rotor for a synchronous motor having a winding and a rotor through which a polyphase alternating current can flow;
(B) applying a voltage corresponding to the torque to be output by the synchronous motor to the winding based on the assumed electric angle; and (c) applying at least the voltage applied in the step (b). Correcting the assumed electrical angle by performing a predetermined calculation using a voltage value of the current, a current value flowing through the winding according to the voltage, and an inductance determined according to characteristics of the motor. A control method for controlling the operation of the synchronous motor by reflecting the corrected electrical angle on the assumption of the electrical angle by the electrical angle estimation means, further comprising: (d) By referring to the relationship previously stored between the electrical angle and the inductance based on the assumed electrical angle, an inductance corresponding to a change in the electrical angle caused by the rotation of the rotor is obtained. A step of calculating a change amount, wherein the predetermined calculation performed in the step (c) is a calculation in consideration of a voltage resulting from the inductance change amount calculated in the step (d). .

In the first motor control device and the control method, it has been described that the change in the inductance greatly affects the detection of the electrical angle. Further, in the calculation conventionally used for detecting the electrical angle, time differentiation is performed assuming that the inductance takes a constant value, that is, p (Ld · Id) = Ld · p (Id). He explained that. However, as shown in FIG. 11, since the inductance changes according to the electrical angle, modeling based on such an assumption includes an error.

According to the second motor control device and motor control method of the present invention, the predetermined calculation performed in the detection of the electrical angle also takes into account the change in inductance.
For example, the calculation is performed by treating the above-described time derivative as p (Ld · Id) = Ld · p (Id) + p (Ld) · Id. The same applies to the inductance Lq. By performing the calculation in consideration of the time change of the inductance as described above, a model for detecting the electrical angle becomes appropriate, and the detection error can be reduced.

As a method of reflecting the time change of the inductance in the arithmetic expression used for controlling the motor,
For example, instead of the above equations (3) and (4), the following equations (7) to (1)
0) can be considered. It goes without saying that various equations equivalent to this are possible. ΔId = Id (n) −Id (n−1) −t (Vd−RId + ωLqIq−Vde) / Ld (7) ΔIq = Iq (n) −Iq (n−1) −t (Vq− RIq−ωLdId−E (n−1) −Vqe) / Lq (8) Here, Vde and Vqe are voltage fluctuations generated based on a change in inductance, respectively, and Vde = [Ld (n) −Ld (N−1)] · Id / T (9) Vqe = [Lq (n) −Lq (n−1)] · Iq / T (10) Ld (n), Ld (n-1), etc. are currents Id
In the same manner as described above for (n) and the like, the differential operation is replaced with the difference. The relationship between the inductance and the electrical angle can be stored by various methods as in the first motor control device and the control method. Further, only one of the error voltages Vde and Vqe may be considered. In this case, it is needless to say that it is desirable to consider the one that has a greater influence on the detection of the electrical angle.

A third motor control device of the present invention is a motor control device for controlling the operation of a synchronous motor having a winding and a rotor through which a polyphase alternating current can flow, wherein the electric angle of the rotor and the electric angle Storage means in which the relationship with the inductance of the winding is stored in advance, and electrical angle detection means for detecting the electrical angle,
Inductance change amount calculation for calculating an inductance change amount according to a change in the electric angle caused by the rotation of the rotor by referring to the relationship stored in the storage unit based on the detected electric angle. Means, a predetermined calculation using a current value flowing through the winding and a current value corresponding to a torque to be output by the motor, wherein the inductance change amount calculated by the inductance change amount calculation means is Voltage calculation means for performing a predetermined calculation in consideration of the resulting voltage to obtain a voltage to be applied to the winding; and a voltage for applying the obtained voltage to the winding according to the electrical angle of the rotor. The gist is to provide an application unit.

The third synchronous motor control method of the present invention is as follows.
A control method for controlling the operation of a synchronous motor having a winding and a rotor through which a polyphase alternating current can flow, comprising: (a) a step of detecting an electrical angle of the winding; Based on the angle, by referring to a relationship stored in advance between the electrical angle of the rotor and the inductance of the winding, the amount of change in the inductance according to the change in the electrical angle caused by the rotation of the rotor Calculating (c)
A predetermined calculation using a current value flowing through the winding and a current value according to a torque to be output by the motor, and calculating a voltage resulting from the inductance change amount calculated by the inductance change amount calculation unit. Performing a predetermined calculation in consideration of the voltage to be applied to the winding,
(D) applying the determined voltage to the winding according to the electrical angle of the rotor.

As described above, the so-called PI control is used for controlling the voltage applied to each phase of the synchronous motor in accordance with the torque to be output. If the inductance corresponding to the resistance of the synchronous motor is constant,
By such control, an appropriate current can be passed. However, as described above, the inductance of the synchronous motor changes according to the electrical angle. Therefore, when the PI control is performed on the assumption that the inductance is constant, there is a possibility that a current different from a current to be originally flowing may flow.
This is the cause of the occurrence of torque ripple in the synchronous motor due to the conventional current control. This does not depend on whether or not the synchronous motor is controlled sensorlessly. As a result of clarifying that the cause of the sensorless electrical angle detection error is the change in inductance, the present inventor has noticed the magnitude of the influence of the change in inductance on the control of the motor, and conceived the influence on the current control. did.

According to the motor control device and the control method described above, in the current control for flowing the current for outputting the torque to the synchronous motor, the current is applied to the winding in consideration of the voltage fluctuation caused by the change in the inductance. Calculate the power voltage. Therefore, an appropriate current can be passed through the winding, and torque ripple can be reduced. Incidentally, the present invention, when controlling the synchronous motor sensorless,
And when the control is performed using a sensor that detects an electrical angle.

As a method of calculating the voltage to be applied to the winding by reflecting the voltage fluctuation caused by the change in the inductance, for example, the voltage value given in the following equations (11) and (12) is calculated by the PI control described above. A method of adding to the voltage value obtained by the above is conceivable. Vdh = Kdh · p (Ld) · Id (11) Vqh = Kqh · p (Lq) · Iq (12) Kdh and Kqh are gains, and are obtained by experiments according to the characteristics of the motor. Is set. In the actual control process, the differential operation may be replaced with a difference operation.

When the synchronous motor is mounted on a so-called hybrid vehicle, the following hybrid vehicle inventions can be constructed by applying the various synchronous motor control devices described above.

The first hybrid vehicle according to the present invention includes a synchronous motor having a winding through which a polyphase alternating current can flow and a rotor, a prime mover, and motor control means for controlling the operation of the synchronous motor. A hybrid vehicle operable with power output from a synchronous motor, wherein the motor control means includes an electrical angle estimation means for assuming an electrical angle of a rotor of the synchronous motor, and a torque to be output by the synchronous motor. A voltage applying means for applying a voltage according to the above to the winding based on the assumed electric angle, a storage means in which a relationship between an electric angle of the rotor and an inductance of the winding is stored in advance, and By referring to the relationship stored in the storage unit based on the assumed electrical angle, an inductance calculation unit that calculates an inductance according to the electrical angle is reduced. Also, by performing a predetermined calculation using a voltage value of the voltage applied by the voltage application unit, a current value flowing through the winding according to the voltage, and the inductance calculated by the inductance calculation unit, Comprising an electrical angle correction means for correcting the assumed electrical angle,
The gist is a means for controlling the operation of the synchronous motor by reflecting the corrected electrical angle on the assumption of the electrical angle by the electrical angle estimation means.

A second hybrid vehicle according to the present invention includes a synchronous motor having a winding capable of flowing a polyphase alternating current and a rotor, a prime mover, and motor control means for controlling the operation of the synchronous motor. A hybrid vehicle operable by a power output from a synchronous motor, wherein the motor control unit is configured to determine an electrical angle of the rotor by an electrical angle estimation unit, and to control a torque to be output by the synchronous motor. A voltage applying unit that applies a voltage to the winding based on the assumed electrical angle, a storage unit that stores a relationship between an electrical angle of the rotor and an inductance of the winding in advance, By referring to the relationship stored in the storage means based on the electrical angle, the amount of change in inductance according to the change in electrical angle caused by rotation of the rotor is calculated. Means for calculating a change in the inductance, at least a voltage value of the voltage applied by the voltage applying means, a value of a current flowing through the winding according to the voltage, and a change in the inductance calculated by the means for calculating the inductance change. Electrical angle correction means for correcting the assumed electrical angle by performing a predetermined calculation using the quantity and the electrical angle, and reflecting the corrected electrical angle on the assumption of the electrical angle by the electrical angle estimation means. Accordingly, the gist is a means for controlling the operation of the synchronous motor.

A third hybrid vehicle according to the present invention includes a synchronous motor having a winding capable of flowing a polyphase alternating current and a rotor, a prime mover, and motor control means for controlling the operation of the synchronous motor. A hybrid vehicle operable by power output from a synchronous motor, wherein the motor control means includes: storage means for storing in advance a relationship between an electrical angle of the rotor and an inductance of the winding; Electrical angle detecting means for detecting the electrical angle, and by referring to the relationship stored in the storage means based on the detected electrical angle, the inductance of the inductance according to the change in electrical angle caused by the rotation of the rotor A predetermined calculation using an inductance change amount calculating means for calculating the change amount, and a current value flowing through the winding and a current value corresponding to a torque to be output by the motor. A voltage calculation means for performing a predetermined calculation in consideration of a voltage resulting from the inductance change amount calculated by the inductance change amount calculation means to obtain a voltage to be applied to the winding; and And voltage applying means for applying voltage to the winding according to the electrical angle of the rotor.

According to each of the hybrid vehicles described above, since the control device for the synchronous motor described above is mounted, torque can be output from the synchronous motor without pulsation. As a result, the riding comfort of the hybrid vehicle can be improved. Further, by improving the operating efficiency of the synchronous motor, the advantage of the hybrid vehicle, which is said to have a low fuel consumption rate, can be further increased.

[0043]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) Configuration of Example Hereinafter, an embodiment of the present invention will be described using an example. FIG. 1 is a block diagram showing a schematic configuration of a motor control device 10 as one embodiment of the present invention, FIG. 2 is an explanatory diagram showing a schematic configuration of a three-phase synchronous motor 40 to be controlled, and FIG. FIG. 3 is an end view showing a relationship between a stator 30 and a rotor 50 of the three-phase synchronous motor 40.

First, referring to FIG.
Will be described. This three-phase synchronous motor 40
Is composed of a stator 30, a rotor 50, and a case 60 for accommodating them. The rotor 50 has permanent magnets 51 to 54 affixed to its outer periphery, and rotatably supports a rotating shaft 55 provided at the center of the shaft by bearings 61 and 62 provided in a case 60.

The rotor 50 is formed by laminating a plurality of plate-like rotors 57 formed by stamping non-oriented electrical steel sheets. As shown in FIG. 3, the plate-like rotor 57 has four salient poles 71 to 74 at orthogonal positions. After laminating the plate-like rotors 57, the rotating shaft 55 is press-fitted, and the laminated plate-like rotors 57 are temporarily fixed. The plate-like rotor 57 made of this electromagnetic steel sheet has an insulating layer and an adhesive layer formed on its surface, and is heated to a predetermined temperature after lamination, and is fixed by melting the adhesive layer.

After the rotor 50 is thus formed, the permanent magnets 51 to 54 are attached to the outer peripheral surface of the rotor 50 at intermediate positions between the salient poles 71 to 74 in the axial direction. The permanent magnets 51 to 54 are magnetized in the radial direction of the rotor 50, and the polarity of adjacent magnets is different from each other. For example, the outer peripheral surface of the permanent magnet 51 is an N pole, and the outer peripheral surface of the adjacent permanent magnet 52 is an S pole.
It is a pole. The permanent magnets 51 and 52 are
0 is assembled to the stator 30, the plate-like rotor 57
And a magnetic path Md penetrating the plate-shaped stator 20 (FIG. 3).
See broken line).

The plate-like stator 20 constituting the stator 30 is
Like the plate-like rotor 57, it is formed by punching a thin sheet of non-oriented electrical steel sheet, and as shown in FIG.
The teeth 22 are provided. A coil 32 for generating a rotating magnetic field in the stator 30 is wound around a slot 24 formed between the teeth 22. In addition, a bolt hole for passing a fixing bolt 34 is provided at an outer edge portion of the plate-shaped stator 20, but is not shown in FIG. 3.

The stator 30 is temporarily fixed by heating and melting the adhesive layer while the plate-like plate-like stators 20 are laminated and pressed against each other. In this state, the coil 32 is wound around the teeth 22 to complete the stator 30, which is assembled to the case 60, and the fixing bolts 34 are inserted into the bolt holes.
And tighten it to secure the whole. Further, the three-phase synchronous motor 40 is completed by assembling the rotor 50 rotatably by the bearings 61 and 62 of the case 60.

When an exciting current is applied to the coil 32 of the stator 30 so as to generate a rotating magnetic field, as shown in FIG. 3, the magnetic path Mq penetrates the adjacent salient poles and the plate-like rotor 57 and the plate-like stator 20. Is formed. Note that an axis through which the magnetic flux formed by the above-described permanent magnet 51 passes through the rotor 50 in the radial direction through the center of the rotation axis is referred to as a d-axis, and is electrically connected to the d-axis in the rotation plane of the rotor 50. The axis orthogonal to is called the q-axis.
That is, the d-axis and the q-axis are axes that rotate as the rotor 50 rotates. In the present embodiment, the permanent magnets 51 and 53 attached to the rotor 50 have N poles on the outer peripheral surface,
Since the outer peripheral surfaces of the permanent magnets 52 and 54 have S poles, the q-axis is geometrically located in the 45-degree direction with respect to the d-axis as shown in FIG. FIG. 4 shows an equivalent circuit of the three-phase synchronous motor 40 of the present embodiment. As shown in FIG. 4, the three-phase synchronous motor 40 is represented by an equivalent circuit having U, V, and W three-phase coils and a permanent magnet that rotates around a rotation axis center.
The d-axis is represented as an axis passing through the N-pole side of the permanent magnet as a positive direction in this equivalent circuit. The electrical angle is the rotation angle θ between the axis passing through the U-phase coil and the d axis.

Next, the configuration of the motor control device 10 will be described with reference to FIG. The motor control device 10 controls the three-phase (U, V, W phase) motor current of the three-phase synchronous motor 40 in response to an external torque command.
100, current sensors 102 and 103 for detecting the U-phase current Au and the V-phase current Av of the three-phase synchronous motor 40, filters 106 and 10 for removing high-frequency noise of the detected current
7. Two analog-to-digital converters (ADCs) 112 and 113 for converting the detected current value into digital data
It is composed of Since the sum of the currents of the U, V, and W phases is always kept at 0, the current of the W phase can be calculated from the current values of the U and V phases without detecting the current of the W phase. In this embodiment, a sensor for detecting the electric angle of the synchronous motor 40 is not provided, and the detection is performed without a sensor.

As shown, a microprocessor (CP) for performing arithmetic and logic operations is provided in the control ECU 100.
U) 120, a ROM 122 preliminarily storing the processing performed by the CPU 120 and necessary data, a RAM 124 for temporarily reading and writing data necessary for the processing, a clock 126 for clocking, and the like, which are interconnected by a bus. Have been. An input port 116 and an output port 118 are also connected to this bus, and the CPU 120 transmits the U and V of the three-phase synchronous motor 40 through these ports 116.
Currents Au and Av flowing through each phase can be read.

Further, the control ECU 100 has a voltage application unit for applying a voltage between the coils of the motor so as to obtain the respective phase currents Au, Av, Aw of the motor determined based on the torque command separately input. 130 is provided at the output. Control output Gu, G from CPU 120
The voltages v, Gw, and SD are output to the voltage application unit 130, and the voltage applied to each coil of the three-phase synchronous motor 40 can be externally controlled. The voltage applying unit 130 is configured mainly with a transistor inverter. The transistor inverter has a circuit configuration in which two transistors are connected as a set to the source side and the sink side of the main power supply for each of U, V, and W phases. By the so-called PWM control, the control outputs Gu, G
When each transistor constituting the transistor inverter is turned on / off according to v and Gw, a pseudo sine wave alternating current flows through each coil 32 of the synchronous motor 40 to generate a rotating magnetic field. The interaction between the rotating magnetic field and the magnetic field formed by the permanent magnet 51 and the like of the rotor 50 causes the rotor 50 to rotate.

(2) Current Control of Motor Next, the concept of current control in the motor control device 10 in this embodiment will be described with reference to FIG. In FIG. 4, when a current Au flows in the U phase, a magnetic field is generated. This magnetic field is generated in a direction penetrating the U phase, and its magnitude changes according to the current Au. Therefore, the U-phase current can be represented as a vector quantity having the direction of the magnetic field and the magnitude Au. The currents Av and Aw flowing in the other V-phase and W-phase can also be represented as vector quantities. When the current is considered as a vector in this way, the current vector in the plane is represented as the sum of representative current vectors in two directions. This 2
If the directions are assumed to be the α direction and the β direction in FIG. 4, a current vector corresponding to a magnetic field generated in an arbitrary direction on the motor rotation surface can be represented using the currents Aα and Aβ flowing through these two-phase coils. Specifically, currents Aα and Aβ equivalent to certain currents Au, Av and Aw can be obtained by the following equation (13). Aα = Au−Av / 2−Aw / 2 Aβ = √3 / 2 · (Aw−Av) (13)

Conversely, when Aα and Aβ are determined, the sum of the U, V, and W phase currents is 0 (Au + Av + Aw).
= 0), the currents Au, Av, and Aw of the respective phases can be obtained by the following equation (14). Au = 2 (√3-3) · Aα / 3 Av = (3-√3) · (Aα−Aβ) / 3 Aw = (3-√3) · (Aα + Aβ) / 3 (14) Is a generally known three-phase / two-phase conversion. Hereinafter, the current control of the motor using the currents Aα and Aβ after the two-phase conversion will be described for simplicity.

The above-mentioned current vector can be defined also for the magnetic field generated in the d-axis direction and the q-axis direction in FIG. Assuming that the magnitudes of the current vectors in the d-axis direction and the q-axis direction are Ad and Aq, the current A in the α direction and the β direction
It is expressed by the following equation (15) using α and Aβ. Ad = Aα · cos θ + Aβ · sin θ Aq = −Aα · sin θ + Aβ · cos θ (15)

Conversely, if Ad and Aq have been determined, A
α and Aβ are obtained by the following equation (16). Aα = Ad · cos θ−Aq · sin θ Aβ = Ad · sin θ + Aq · cos θ (16)

From the above, if the currents flowing in the d-axis and q-axis directions of the motor are obtained, the two-phase currents Aα and Aβ can be obtained from equation (16).
The current to be passed through the V and W phases can be obtained. Also,
The voltages to be applied to the U, V, and W phases can also be determined.
Of course, it is also possible to directly obtain and control the relationship between the d-axis and q-axis directions and the U, V, and W phase currents without interposing the α direction and the β direction. The current control of the motor in this embodiment is performed based on such a concept. In the following description, for example, “d-axis, q-axis current” means the magnitude of the current vector based on the above concept. Note that the current flowing through the motor is represented by the d-axis,
When considered in the q-axis direction, it is generally known that the q-axis current is a current that mainly controls the torque of the motor.

(3) Motor Control Processing Next, the motor control processing of this embodiment will be described with reference to FIG. The motor control process routine shown in FIG. 5 is a routine that the CPU 120 of the control ECU 100 shown in FIG. 1 periodically executes together with other control processes. As shown in FIG. 5, in the motor control routine, the CPU 120 detects an electrical angle by an electrical angle detection process (step S100), and performs a current control process based on the detected electrical angle (step S200). The current control process means that the stator 3
This is a process for generating a torque by passing a current through the coil 32 wound around zero. Fig. 6 for each process
This will be described below with reference to FIG.

FIG. 6 shows the flow of the electrical angle detection processing routine. When this process is started, the CPU 120 sets the electrical angle to a value θc based on the control performed so far.
(See FIG. 4). Further, a current corresponding to the torque to be output is flowing through the coil 32 of the stator 30 based on the control performed so far. The electric angle detection processing routine obtains an electric angle as a detection value by correcting the assumed electric angle θc by the following processing. When the electrical angle detection process is started, the CPU 1
20 detects the d-axis current Id and the q-axis current Iq (step S110). These currents are obtained by subjecting the currents Au and Av flowing in the U-phase and V-phase detected by the current sensors 102 and 103 shown in FIG. The coordinate conversion is performed using the assumed electrical angle θc.

Next, the CPU 120 reads the inductance (step S120). In this embodiment, the relationship between the inductances Ld and Lq and the electrical angle shown in FIG. 11 is tabulated and stored in the ROM 122 (see FIG. 1) in advance. In step S120, the assumed electrical angle θ
The inductances Ld and Lq corresponding to c are read from this table. The relationship between the inductance and the electrical angle may be stored in such a table format, or may be stored by approximating it with a function. Further, the inductances Ld and Lq may be stored separately, or a value obtained by combining the two may be stored.

The inductance L thus read out
Using d and Lq, the CPU 120 determines the error voltages Vde and V
Calculate qe. The calculation formulas are the following formulas (17) and (18). Vde = [Ld (n) −Ld (n−1)] · Id / T (17) Vqe = [Lq (n) −Lq (n−1)] · Iq / T (18) Here, the inductances Ld (n) and Lq (n)
Means the value read in step S120. On the other hand, the inductance Ld (n-
1) and Lq (n-1) are the inductance values when the electric angle detection processing routine was executed last time. Also T
Is a time corresponding to a cycle of executing the electric angle detection processing routine. That is, the above equations (17) and (18) are obtained by multiplying the current by the temporal change rate of the inductances Ld and Lq.

The current values Id, Iq detected by the above processing
And using the calculated error voltages Vde, Vqe
U120 calculates △ Id, △ Iq, E (n) (step S140). Each value is calculated by the following equations (19) to (21). ΔId = Id (n) −Id (n−1) −T (Vd−RId + ωLqIq−Vde) / Ld (19) ΔIq = Iq (n) −Iq (n−1) −T (Vq− RIq−ωLdId−E (n−1) −Vqe) / Lq (20) E (n) = E (n−1) −K1 △ Iq (21)

(N) and the like attached to each variable are as follows:
As described in the calculation of the error voltages Vde and Vqe, the description is given based on the fact that the electrical angle detection processing routine is periodically and repeatedly executed. (N) is step S1
10, (n-1) means the value detected when the electrical angle detection processing routine was executed last time. That is, Id (n) -Id (n-
The portion 1) indicates the amount of change in the current Id from the time when the electric angle detection processing routine was last executed to the time this time. T indicates a cycle in which the electrical angle detection processing routine is executed. In the above equations (20) and (21), in the portions simply described as Id and Iq, the previous detection values (Id (n-1), Iq (n-1)) and the current detection values (Id ( n), Iq (n)), but it is preferable to use the former or latter value.

Regarding other variables, Vd and Vq are voltage values applied to the windings, ω is the rotational angular velocity of the motor, Ld,
Lq is the inductance in the d-axis and q-axis directions. As for the inductances Ld and Lq, the values (Ld (n−
1), Lq (n-1)) and the value (Ld
Although it is desirable to use the average value of (n) and Lq (n)), the former value or the latter value may be used. ω
Is in rad / sec, and the motor rotation speed N
(Rpm) has a relationship of ω = 2π · N / 60. K1 correlates E (n), E (n-1), and △ Iq, and is a gain used for calculating an electrical angle, which will be described later, and is experimentally determined. Voltage values Vd, Vq
Is substituted with the voltage command value output from the CPU 120.

△ Id, △ Iq, E thus calculated
Using (n), an electrical angle θ (n−1) (corresponding to θc in FIG. 4) assumed based on the result of the previous electrical angle detection is converted into a new electrical angle based on the following equation (22). θ (n)
(Step S150). However, sgn means “+” when ω> 0 and “−” when ω <0. K2 and K3 are K
Similar to 1, the gain is used for calculating the electrical angle, and is experimentally determined. Here, since it is assumed that the motor is operating at high speed, the case where the motor is not rotating, that is, the case where ω = 0, is not considered.

The CPU 120 determines the following equation (2) in the next step.
Ω is calculated by 3) (step S160). The value of ω calculated here is used for the calculation of the above equations (20) and (21) when the no-load motor control routine is next executed. The value of ω is determined in step S140 or S1.
At 50, the calculation may be performed together with △ Id or the like.

The electrical angle of the synchronous motor 40 has been detected by the electrical angle detection processing routine described above. Based on this electrical angle, the CPU 120 determines the coil 32 of the stator 30.
, A current control process is executed (see step S200 in FIG. 5). The details of the current control process will be described with reference to FIGS. FIG. 7 is a flowchart showing the flow of the current control processing routine.
Is a block diagram showing the contents of the current control process.

The current control processing routine shown in FIG.
A process 120 is executed periodically. When this process is started, the PCU 120 reads the electrical angle θ (Step S210). This is a value detected by the electrical angle detection processing routine. At the same time, the d-axis currents id and q
The axis current iq is detected (step S210). The currents on the d-axis and the q-axis are the current sensors 102, 1 shown in FIG.
It is obtained by converting the U-phase and V-phase currents detected at step 03 into d-axis and q-axis currents by three-phase / two-phase conversion. This is Figure 8
Corresponds to the processing in the three-phase / two-phase conversion unit 208 in the block diagram of FIG. At the same time as these detections, a torque command value to be output is read (step S210). The torque command value is a value externally designated via the input port 116 (see FIG. 1).

Next, the CPU 120 reads out the inductances Ld and Lq based on the electrical angle θ (step S22).
0). As described in the electric angle detection processing routine, R
By referring to the table stored in the OM 122, the inductances Ld and Lq corresponding to the electrical angle θ are obtained. This corresponds to the processing in the Ld, Lq map 210 of FIG. Further, the CPU 120 determines a current command value i to flow on the d-axis and the q-axis based on the torque command value.
d * and iq * are calculated (step S230). Since the torque output by the motor 50 and the d-axis and q-axis current values have a unique relationship, if a torque command value is set,
Each current command value can be calculated.

Using the quantities obtained by the above processing, the CPU 120 calculates the voltage command values Vd and Vq by the following equation (2).
4), calculated according to (25). Vd = Kp △ id + Σ (Ki △△ id) + Vdh (24) Vq = Kp △ iq + Σ (Ki △△ iq) + Vdh (25) Vd is a voltage value to be applied in the d-axis direction. Means V
q means a voltage value to be applied in the q-axis direction. △ id and △ iq are deviations between the current command values id * and iq * and the current d-axis and q-axis currents id and iq, respectively, and are values expressed by the following equations (26) and (27). Δid = id * -id (28) Δiq = iq * -iq (29)

The calculation of the voltage command values Vd and Vq is based on the voltage command values Vd 'and Vq' obtained based on the so-called PI control.
Is obtained by adding a voltage compensation value to. In the PI control, a portion proportional to the deviation (the above equation (28) (2
The voltage command values Vd 'and Vq' are obtained from the right-hand term (9)) and the accumulation of the deviation for a predetermined number of times in the past (the right-hand second term). This corresponds to the PI operation units 202d and 202q in FIG.
Is equivalent to the processing by. Kp and Ki are proportional coefficients, respectively, and are set according to the characteristics of the motor. The voltage command values Vd 'and Vq' plus the voltage compensation values Vdh and Vqh are the voltage command values Vd and Vq.

The voltage compensation values Vdh and Vqh are the inductances Ld and Lq generated according to the electrical angle during rotation of the motor.
This is a value for compensating for voltage fluctuations based on the change in. The voltage compensation values Vdh and Vqh are respectively the inductance L
d, the time derivative of Lq, that is, the current value i
d, iq (the following equation (30) (3
1)). Vdh = (Ld (m) −Ld (m−1)) / Ti · id (30) Vqh = (Lq (m) −Lq (m−1)) / Ti · iq (31) Here, the variable m in the above equation is a variable used based on the fact that the current control processing routine is periodically performed. Ld (m) and Lq (m) mean the inductance detected in step S220 when executing the current control process, and Ld (m-1) and Lq (m-1) indicate the current control process in the last time. It means the inductance detected when implemented. Ti indicates a cycle in which the current control processing routine is executed. This is because the time differentiators 212d and 212q and the multipliers 214d and 214q in FIG.
Corresponds to the processing in.

When the voltage command values Vd and Vq are calculated in this manner, the CPU 120 performs two-phase / three-phase conversion to obtain U,
The voltages Vu, Vv, Vw to be applied to each phase of V, W are calculated (step S250). The two-phase / three-phase conversion is as described in "(2) Motor current control" above. This corresponds to the processing in the two-phase / three-phase conversion unit 204 in FIG.

Since the actual voltage control is performed by the on / off time of each transistor constituting the transistor inverter of the voltage applying section 130, the CPU 120 controls each transistor so that the voltage command value set by the above processing is realized. PWM control of the on-time of (step S2)
60). The CPU 120 is connected to the output port 11 shown in FIG.
A signal corresponding to the on-time and timing of each transistor is output to Gu, Gv, and Gw via the switch 8. This corresponds to the processing of the PWM control unit 206 in FIG.

According to the motor control device 10 described above, it is possible to operate the synchronous motor 40 while suppressing the torque fluctuation. In particular, the detection error of the electrical angle in the electrical angle detection processing can be made very small. In the present embodiment, the error currents 等 Id and the like are calculated by changing the inductances Ld and Lq according to the electrical angle (step S120 in FIG. 6) and performing calculations in consideration of the change in inductance (step S120). By S140), the detection error of the electrical angle could be suppressed. FIG. 9 shows an electrical angle detection result when the electrical angle detection processing of this embodiment is executed.
FIG. 9 is a graph showing the electrical angle of the rotating synchronous motor 40 with time on the horizontal axis. In FIG. 9, the graph shown by a broken line is a true value, and the graph shown by a solid line is a detected value based on the present embodiment. For comparison, FIG. 12 shows a result of detecting an electrical angle without considering a change in inductance. Except that the inductance is treated as a constant value, the same processing as that of the electric angle detection processing routine of this embodiment (FIG. 6) is performed.

When the electrical angle is detected without considering the change in inductance (FIG. 12), for example, e1 to e
As shown by 6, a detection error appears periodically. On the other hand, when the electrical angle detection processing according to the present embodiment is executed (FIG. 9), it can be seen that such a detection error is drastically reduced. In the present embodiment, by taking into account the change in inductance, the detection accuracy of the electrical angle is significantly improved, and the motor can be operated smoothly. Similarly, in the present embodiment, voltage compensation is performed in consideration of a change in inductance in current control (step S240 in FIG. 8). As a result, the voltage command values Vd and Vq that allow the current command values id * and iq * to flow appropriately according to the change in the inductance can be set, so that the motor can be operated smoothly.

In the above embodiment, the case where the electric angle is controlled without a sensor has been described as an example. However, the current control processing routine (FIG. 8) of the present embodiment uses the sensor using a Hall element to determine the electric angle. It is applicable even when detecting. Further, in the above-described embodiment, in the electric angle detection processing routine, the value of the inductance used for the calculation is changed according to the electric angle (step S120 in FIG. 6).
Although the rate of change in inductance is also considered in the arithmetic expression (step S140), only one of them may be used. If both are performed as shown in this embodiment, the electrical angle can be detected with extremely high accuracy, and if only one of them is used, the content of the electrical angle detection process is simplified. And it can be processed at high speed.

(5) Application Example of Motor Control Device In order to show the usefulness of the motor control device and the motor having the control device in this embodiment, these application examples will be described with reference to FIG. FIG. 10 is an explanatory diagram showing a schematic configuration of a hybrid car to which these are applied. A hybrid car is a vehicle equipped with both an engine and a motor. As described below, the hybrid car shown in FIG. 10 has a configuration in which the power of the engine can be directly transmitted to the drive wheels. Such a hybrid car is particularly called a parallel hybrid car.

First, the schematic structure of the hybrid car shown in FIG. 10 will be described. The engine EG is a gasoline engine or a diesel engine used in a normal vehicle. The crankshaft of the engine EG is mechanically connected to the planetary gear PG. Planetary gear P
G is a sun gear SG that rotates at the center, and a planetary carrier PC that revolves while rotating around the sun gear SG.
And a ring gear RG rotatable around the planetary carrier PC. As is well known, the planetary gear PG includes a sun gear SG, a planetary carrier PC,
When the power input / output to any two of the ring gears RG is determined, the power input / output is determined to one of the remaining ring gears RG.

In the hybrid car of this embodiment, as shown in FIG. 10, the crankshaft of the engine EG is connected to the planetary carrier PC. The generator MG1 is connected to the sun gear SG, and the motor GM2 is connected to the ring gear RG. The ring gear RG is coupled to the drive wheels WH via a power transmission mechanism such as a belt. The generator MG1 and the motor MG2 are each a synchronous motor. The generator MG1 and the motor MG2 are electrically connected to the battery BA, and exchange power with the battery BA.

The operation of the engine EG is controlled by the EFIECU. The generator MG1 and the motor M
G2 is electrically connected to the control unit CU via the drive circuits DU1 and Du2, and the operation is controlled by the control unit CU. The control unit CU indirectly controls the operation of the engine EG by outputting information necessary for controlling the engine to the EFIECU. The correspondence with the motor control device 10 (FIG. 1) in the present embodiment is as follows.
U100, and the drive circuit DU2 includes a voltage application unit 130
, And the motor MG2 corresponds to the motor 40. The current sensors 102 and 103, the filters 106 and 107, and the ADCs 112 and 113 are not shown in FIG.

In the hybrid car having the above configuration, the power output from the engine EG is divided and transmitted by the planetary gear PG. That is, a part is distributed to the sun gear SG and is regenerated as electric power by the generator MG1. This power is stored in battery BA. The remaining power distributed by the planetary gear PG is transmitted to the drive wheels WH via the ring gear RG and used for running the vehicle. The power output from the motor MG2 is also added to the ring gear RG. Control unit CU controls the operation of engine EG, generator MG1, and motor MG2 such that the sum of the power transmitted from engine EG to drive wheels WH and the power output from motor MG2 matches the required power. It is doing. In addition, in such a hybrid car, traveling in various operation modes such as stopping the operation of the engine EG and traveling using only the power output from the motor MG2 is possible.

As described above, the power output from the motor MG2 can be transmitted to the drive wheels WH. For example, if the output torque from the motor MG2 pulsates, the ride comfort of the vehicle is impaired. In the above-described hybrid vehicle, if the motor control device of the present embodiment is provided, it is possible to suppress the fluctuation of the torque output from the motor MG2, so that the riding comfort can be improved. Also,
By making the motor MG2 operable without torque fluctuation, the operating efficiency of the hybrid car can be improved. In the above-mentioned hybrid car, the generator M
G1 is also configured as a synchronous motor, and can also function as a motor that receives power supply and outputs torque depending on the operation mode. Therefore, the present invention can be applied as a control device of the generator MG1.

In the above description, a parallel hybrid car has been described as an example. However, the motor control device of the present invention is applied to a type of hybrid car in which power output from the engine EG cannot be directly transmitted to the drive wheels WH, that is, a so-called series hybrid car. Is also applicable.

As described above, the motor control device of the present invention is very useful in that the motor can be smoothly operated without torque fluctuation. In the above description, a hybrid car is given as an example, but the application example of the motor control device of the present invention is not limited to this.

Although various embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various embodiments can be implemented without departing from the gist of the present invention. For example, in the above invention, the torque ripple is reduced by appropriately controlling the motor, but the maximum torque of the motor is increased by appropriately maintaining the relationship between the magnetic field by the permanent magnet and the magnetic field by the coil winding. It is also possible to apply to various controls.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a motor control device 10.

FIG. 2 is an explanatory diagram showing a schematic configuration of a three-phase synchronous motor 40.

FIG. 3 shows a stator 30 and a rotor 50 of a three-phase synchronous motor 40;
FIG.

FIG. 4 is an equivalent circuit diagram of the three-phase synchronous motor 40.

FIG. 5 is a flowchart showing a flow of a motor control processing routine.

FIG. 6 is a flowchart illustrating processing contents of an electrical angle detection processing routine.

FIG. 7 is a flowchart showing the processing contents of a current control processing routine.

FIG. 8 is an explanatory diagram showing a configuration of current control in a control block.

FIG. 9 is a graph showing an electrical angle detection result according to the present embodiment.

FIG. 10 is an explanatory diagram illustrating a schematic configuration of a hybrid car to which the present embodiment is applied.

FIG. 11 is a graph showing a change in inductance.

FIG. 12 is a graph showing a result of electrical angle detection by a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Motor control apparatus 20 ... Plate stator 22 ... Teeth 24 ... Slot 30 ... Stator 32 ... Coil 34 ... Bolt 40 ... Three-phase synchronous motor 50 ... Rotor 51, 52, 53, 54 ... Permanent magnet 55 ... Rotation Shaft 57 ... Plate rotor 60 ... Cases 61, 62 ... Bearings 71, 72, 73, 74 ... Salient poles 100 ... Control ECUs 102, 103 ... Current sensors 106, 107 ... Filters 112, 113 ... ADC 116 ... Input ports 118 output port 120 CPU 122 ROM 124 RAM 126 clock 130 voltage application unit 202d, 202q PI calculation unit 204 2-phase / 3-phase conversion unit 206 PWM control unit 208 3-phase / 2-phase conversion Unit 210: Ld, Lq map 212d, 212q: Time differentiation unit 214d, 214q: Multiplication unit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) H023P ⁶ /00-6/02

Claims (9)

(57) [Claims] An electric angle estimating means for estimating an electric angle of a rotor of a synchronous motor having a winding capable of flowing a polyphase alternating current and a rotor, and a voltage corresponding to a torque to be output by the synchronous motor. Voltage applying means for applying to the winding based on the assumed electrical angle, at least a voltage value of the voltage applied by the voltage applying means, and a current value flowing through the winding according to the voltage When,
Electrical angle correction means for correcting the assumed electrical angle by performing a predetermined calculation using an inductance determined according to the characteristics of the motor, and A motor control device that controls the operation of the synchronous motor by reflecting the electric angle on the assumption of the electric angle, further comprising a storage unit that stores in advance the relationship between the electric angle of the rotor and the inductance, The motor control device, wherein the electrical angle correction unit uses the inductance obtained by referring to the relationship stored in the storage unit based on the assumed electrical angle in the predetermined calculation. 2. A synchronous motor having a winding capable of flowing a polyphase alternating current and a rotor, an electric angle estimating means for estimating an electric angle of the rotor, and a voltage corresponding to a torque to be output by the synchronous motor. Voltage applying means for applying to the winding based on the assumed electrical angle, at least a voltage value of the voltage applied by the voltage applying means, and a current value flowing through the winding according to the voltage When,
Electrical angle correction means for correcting the assumed electrical angle by performing a predetermined calculation using an inductance determined according to the characteristics of the motor, and A motor control device that controls the operation of the synchronous motor by reflecting the assumption on the electrical angle according to the above, further comprising: storage means that stores in advance the relationship between the electrical angle of the rotor and the inductance; An inductance change amount calculating unit that calculates a change amount of an inductance according to a change in an electric angle caused by rotation of the rotor by referring to a relationship stored in the storage unit based on the obtained electrical angle. Wherein the predetermined calculation performed by the electrical angle correction means is based on the inductance change amount calculated by the inductance change amount calculation means. Motor controller according to the operation in consideration of the voltage. 3. A motor control device for controlling the operation of a synchronous motor having a winding and a rotor through which a polyphase alternating current can flow, wherein a relationship between an electrical angle of the rotor and an inductance of the winding is determined in advance. A storage unit that stores the electric angle; an electric angle detection unit that detects the electric angle; and a relation generated with the rotation of the rotor by referring to a relationship stored in the storage unit based on the detected electric angle. An inductance change amount calculating means for calculating a change amount of an inductance according to a change in an electrical angle; and a predetermined calculation using a current value flowing through the winding and a current value according to a torque to be output by the motor. A voltage calculation means for performing a predetermined calculation in consideration of a voltage resulting from the inductance change amount calculated by the inductance change amount calculation means to obtain a voltage to be applied to the winding. When a motor control device and a voltage applying means for applying the sought voltage to the winding in response to an electrical angle of the rotor. 4. A synchronous motor having a winding and a rotor through which a polyphase alternating current can flow, (a) estimating an electrical angle of the rotor; and (b) determining a torque to be output by the synchronous motor. Applying a corresponding voltage to the winding based on the assumed electrical angle; and (c) at least a voltage value of the voltage applied in the step (b) and the winding according to the voltage. A step of correcting the assumed electrical angle by performing a predetermined calculation using a current value flowing through the wire and an inductance determined according to the characteristics of the motor, and calculating the corrected electrical angle. A control method for controlling the operation of the synchronous motor by reflecting the electric angle on the assumption of the electric angle by the electric angle estimating means, further comprising: (d) a relation previously stored for the electric angle of the rotor and the inductance. Calculating an inductance corresponding to the electrical angle by referring to the assumed electrical angle, wherein the inductance used in the step (c) is calculated in the step (d). Control method of synchronous motor which is inductance. 5. A synchronous motor having a winding and a rotor through which a polyphase alternating current can flow, (a) estimating an electric angle of the rotor; and (b) determining a torque to be output by the synchronous motor. Applying a corresponding voltage to the winding based on the assumed electrical angle; and (c) at least a voltage value of the voltage applied in the step (b) and the winding according to the voltage. A step of correcting the assumed electrical angle by performing a predetermined calculation using a current value flowing through the wire and an inductance determined according to the characteristics of the motor, and calculating the corrected electrical angle. A control method for controlling the operation of the synchronous motor by reflecting the electric angle on the assumption of the electric angle by the electric angle estimating means, further comprising: (d) a relation previously stored for the electric angle of the rotor and the inductance. A step of calculating a change amount of an inductance according to a change of an electric angle caused by rotation of the rotor by referring to the electric angle based on the assumed electric angle, and performed in the step (c). The method of controlling a synchronous motor, wherein the predetermined calculation is a calculation considering a voltage resulting from the inductance change amount calculated in the step (d). 6. A control method for controlling the operation of a synchronous motor having a winding and a rotor through which a polyphase alternating current can flow, comprising:
(A) detecting an electrical angle of the winding; and (b) referring to a relationship stored in advance between the electrical angle of the rotor and the inductance of the winding based on the detected electrical angle. (C) calculating a change in inductance according to a change in electrical angle caused by rotation of the rotor; and (c) calculating a current value flowing through the winding and a torque to be output by the motor. A predetermined calculation using the corresponding current value and taking into account the voltage resulting from the inductance change amount calculated by the inductance change amount calculation means, to perform the voltage to be applied to the winding. A synchronous motor control method comprising: a step of obtaining; and (d) a step of applying the obtained voltage to the winding according to an electrical angle of the rotor. 7. A synchronous motor having a winding capable of flowing a polyphase alternating current and a rotor, a prime mover, and motor control means for controlling operation of the synchronous motor, wherein at least power output from the synchronous motor is provided. In a hybrid vehicle that is capable of traveling, the motor control means includes: an electric angle estimation means for estimating an electric angle of a rotor of the synchronous motor; and a voltage corresponding to a torque to be output by the synchronous motor. Voltage applying means for applying to the winding based on the obtained electrical angle, storage means for storing in advance the relationship between the electrical angle of the rotor and the inductance of the winding, and based on the assumed electrical angle An inductance calculating means for calculating an inductance corresponding to the electrical angle by referring to the relationship stored in the storage means; A voltage value of the applied voltage, a current value flowing through the winding according to the voltage value,
An electrical angle correction unit that performs a predetermined calculation using the inductance calculated by the inductance calculation unit and corrects the assumed electrical angle, wherein the corrected electrical angle is calculated by the electrical angle estimation unit. A hybrid vehicle which is a means for controlling the operation of the synchronous motor by reflecting the electric angle in an assumption. 8. A synchronous motor having a winding and a rotor through which a polyphase alternating current can flow, a prime mover, and motor control means for controlling operation of the synchronous motor, wherein at least the power output from the synchronous motor A hybrid vehicle that is capable of traveling, wherein the motor control means includes: an electric angle estimation means for estimating an electric angle of the rotor; and a voltage corresponding to a torque to be output by the synchronous motor. Voltage applying means for applying to the winding based on an angle; storage means for storing in advance the relationship between an electrical angle of the rotor and inductance of the winding; and storing means based on the assumed electrical angle. An inductance change amount calculating means for calculating an amount of change in inductance according to a change in electrical angle caused by rotation of the rotor by referring to the relationship stored in At least, a voltage value of the voltage applied by the voltage applying means, and a current value flowing through the winding according to the voltage,
An electrical angle correction unit that corrects the assumed electrical angle by performing a predetermined calculation using the inductance change amount calculated by the inductance change amount calculation unit; and A hybrid vehicle as a means for controlling the operation of the synchronous motor by reflecting the electric angle in the electric angle estimation means. 9. A synchronous motor having a winding and a rotor through which a polyphase alternating current can flow, a prime mover, and motor control means for controlling operation of the synchronous motor, wherein at least power output from the synchronous motor is used. A hybrid vehicle that is capable of traveling, wherein the motor control unit includes a storage unit that stores in advance a relationship between an electrical angle of the rotor and an inductance of the winding; and an electrical angle detection unit that detects the electrical angle. An inductance change amount for calculating an inductance change amount according to a change in an electrical angle caused by rotation of the rotor by referring to a relationship stored in the storage unit based on the detected electrical angle; A predetermined calculation using a current value flowing through the winding and a current value according to a torque to be output by the motor, Voltage calculation means for performing a predetermined calculation in consideration of a voltage resulting from the inductance change amount calculated by the calculation means to obtain a voltage to be applied to the winding; and obtaining the obtained voltage as an electrical angle of the rotor. And a voltage applying means for applying a voltage to the winding according to the following.