JPH10170307A - Device for detecting position of magnetic pole of rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for detecting the position of magnetic pole of a rotary electric machine which can continuously detect the position of the magnetic pole of the rotary electric machine even when the signal line of a sensor is disconnected. SOLUTION: In a device for detecting the position of magnetic pole which is provided with a disk 2 and three regularly positioned sensors 3A, 3B, and 3C so that the device can detect the position of the magnetic pole of a rotary electric machine by detecting the reference position of the magnetic pole at every 60 deg. electrical angle from a combination of output pulses PU, PV, and PW and the relative position of the pole with a rotary encoder, an arithmetic means is constituted so that the means can compute the position of the magnetic pole by using the present electrical-angle rotating speed based on the output signal of the encoder and control sample time by software on the basis of the position of the magnetic pole detected at the preceding time when one of signal lines for electrically transmitting the signals P1 , P2 , and P3 of the sensors is disconnected or from the electrical-angle rotating speed estimated from reference positional signals detected at π/3 intervals obtained from the pulses PU, PV, and PW and the measured results of the changing duration of the reference positional signals when the signal line for electrically transmitting the output signal of the rotary encoder is disconnected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic pole position detecting device for a rotating electric machine, and is particularly useful when the sensor portion is disconnected.

[0002]

2. Description of the Related Art For example, vector control has been proposed as a method of operating a synchronous motor having a permanent magnet rotor as a field with the same characteristics as a DC motor.

Since it is necessary to detect the magnetic pole position of the rotor in order to realize this vector control, various magnetic pole position detecting devices have been conventionally proposed. As one of them, there is a "magnetic pole position detecting device of a rotating electric machine" according to Japanese Patent Application No. 06-189163.

FIG. 1 is a block diagram showing a case where the magnetic pole position detecting device is applied to an 8-pole rotating field type motor. As shown in the figure, this magnetic pole position detecting device has an electrical angle of 60.
Reference position detection unit I for detecting the absolute position of the rotation axis for each ° (15 ° mechanical angle), relative position detection unit II for finely dividing the relative position between adjacent reference positions, and reference An arithmetic unit III for processing the output signals of the position detection unit I and the relative position detection unit II to calculate the rotational position of the rotary shaft.

[0005] As shown in FIG.
It has a disk 2 fixed to the rotating shaft 1 and rotating integrally with the rotating shaft 1 and three sensors 3A, 3B, 3C. As shown particularly in FIG. 2 (a), the disk 2 has a convex portion 2a and a concave portion 2b at its outermost peripheral portion in the circumferential direction.
Are alternately formed at every 180 ° electrical angle (45 ° mechanical angle). Each of the sensors 3A, 3B, and 3C has a light-emitting unit 3a and a light-receiving unit 3b, as shown particularly in FIG. 2B, and shows a circle between the light-emitting unit 3a and the light-receiving unit 3b. The plate 2 is arranged evenly in the circumferential direction so that the convex portion 2a or the concave portion 2b is located. That is, the sensor 3A
2C to 3C, as shown in FIG.
They are disposed and fixed at positions separated by a mechanical angle of 120 ° in the circumferential direction so as to correspond to the V and W phases, respectively. At this time, the position of the disk 2 is adjusted so that the voltage induced in the U-phase of the stator winding due to the rotating magnetic field and the phase of the sensor 3A match, that is, the relationship shown in FIG. It is.

When performing vector control, it is necessary to detect the absolute position of the magnetic field. However, by performing the adjustment as described above, in the control of the permanent magnet motor, the output pulse P _U
Since the position of the magnetic field at the time of rising coincides with the U-phase winding, this can be used as a reference point for the absolute position of the magnetic field.

The pulse generating circuit 4 shown in FIG. 1 generates a reference position pulse for every π / 3 in electrical angle based on the rising and falling points of the output pulses P _U , P _V and P _W of the sensors 3A, 3B and 3C. P _S. FIG. 4 shows the waveform at this time. As shown in the figure, the output pulses P _U , P _V ,
P _W is configured so that the phases thereof match the induced voltages U, V, and W of the U phase, V phase, and W phase of the stator winding, respectively, and P _S-0 , P _S−1 , PS _-2 , PS _-3 , ... are absolute position pulses.

The relative position detecting section II includes a disk section 5, a sensor section 6
a, 6b, forward / reverse pulse generating circuit 7 and counter 8
And a rotary encoder composed of: The disk portion 5 has a number of slits formed at regular intervals in the circumferential direction, and is fixed to the rotating shaft 1 so as to detect a subdivided rotation angle between reference positions every π / 3. Sensor part 6
a, 6b is intended to convert this by sensing the light transmitted through the slit of the circular plate portion 5 into an electric signal, the number of A-phase pulse signal P _A and B-phase pulse signal corresponding to the amount of rotation of the rotary shaft 1 the P _B sends each. The A-phase pulse signal P _A and the B-phase pulse signal P _B have the same frequency but are shifted in phase by π / 2, so that the A-phase pulse signal P _A and the B-phase pulse P _B
And the rotation direction of the rotating shaft 1 can be detected based on the relationship. Forward / reverse pulse generating circuit 7 is A-phase pulse signals P _A and B
The rotation direction of the rotary shaft 1 is detected based on the phase pulse signal P _B, and an addition pulse signal P _up or a subtraction pulse signal P corresponding to the number of pulses generated by the sensor units 6a and 6b.
_{Send down} . In this example, 720 A and B phase pulse signals P _A and P _B are generated by one rotation of the disk portion 5, but in this case, 360 ° / 720 pulses = 0.5 / Since the accuracy of one pulse is not sufficient,
Reverse pulse generating circuit 7, the A-phase or B-phase pulse signals P _A, P _B quadruple, namely the A-phase or B-phase pulse signals P _A, subtraction pulse signal P _{Stay up-raised} to 4 times the frequency of the P _B, P _down . Predetermined value is preset for each input of the reference position pulse P _s is the counter 8, further input subtraction pulse signal P _{Stay up-,} the number of pulses P _down is added or subtracted to a predetermined value. That is, during forward rotation, the number of pulses obtained by adding the rotation position from the reference position to a predetermined value is counted, and during reverse rotation, the number of pulses obtained by subtracting the rotation position from the reference position from the predetermined position is counted. Thus, the counter 8 sends out the count signal _Pc which is the relative position information between the reference positions.

As described above, by adding / subtracting the number of pulses based on the addition / subtraction pulse signals P _up and P _down from the preset value, the arithmetic unit III detects the difference between the preset value and the count value to determine whether the rotation is normal or reverse. The relative position information can be obtained without performing.

The operation unit III includes a high-speed operation processor (DS)
P), the output pulses P _U , P _V , P _W of the sensors 3A, 3B, 3C are processed, and the position coincident with the U-phase winding is set to 0 °. position determining the relative position based on the count signal P _C with seeking.

More specifically, the reference position is obtained from the table shown in Table 1. This table takes the clockwise direction of the disk 1 in the positive direction, and sets the output pulses P _U , P _V , and P _{W to} the “Low state”.
Corresponds to “1” and “High state” corresponds to “0”.

[0012]

[Table 1]

The relative position θ ₁ is obtained by the following equation (Equation 1).

[0014]

(Equation 1)

Therefore, the rotation position is obtained as the sum of the reference position θ ₀ and the relative position θ ₁ . At this time, θ ₁ <
0, that is, a value obtained by adding 60 ° to the absolute position θ ₀ obtained based on Table 1 as the reference position at the time of reverse rotation.

In this magnetic pole position detecting device, a reference position of the rotary shaft 1 at every 60 ° in electrical angle is determined by a combination of binary signals transmitted from the three sensors 3A, 3B, 3C, and the reference position is detected by an encoder. By taking into account the relative position between the absolute positions, the magnetic pole position can be accurately detected via the rotational position of the rotating shaft.

[0017]

However, in the magnetic pole position detecting device as described above, the sensors 3A to 3C and the sensor section 6 are not required.
If the signal line for transmitting the output signals a and 6b is broken, the position of the magnetic pole cannot be detected, so that the control becomes unstable and the inverter is finally stopped.

An object of the present invention is to provide a magnetic pole position detecting device of a rotating electric machine which can continuously detect a magnetic pole position even when a signal line of a sensor is broken, in view of the above conventional technology.

[0019]

The structure of the present invention that achieves the above object has the following features.

1) One state every 180 ° in electrical angle
Another state different from this alternates adjacently in the circumferential direction
Circle fixed to the rotating shaft of the rotating electric machine
At a mechanical angle of 120 ° relative to the plate in the circumferential direction
And one of the above-mentioned ones, which are arranged in
State and other states, and respond to each state.
U-phase, V-phase and W-phase voltage-based binary signals
Some P_U, P_VAnd P _WThree signals that each send out a signal
Along with a sensor and information indicating forward and reverse rotation of the rotary shaft,
The reference position, which is the transition point between the one state and the other state
Generates a number of pulses according to the rotation angle that subdivides the interval
The disk attached to the rotating shaft and close to the disk
A rotary encoder having a sensor unit disposed as
The combination of the binary signals sent from the three sensors
When detecting the reference position of the rotation axis at every 60 degrees in the air angle
A signal representing the reference position and the rotary encoder
Between adjacent reference positions, which is the output signal of the
And processing the signal representing the relative position to obtain the rotational position of the rotary shaft.
Calculating means for calculating the magnetic pole position based on the position
In the magnetic pole position detecting device of the electric machine,₁, P_Twoas well as
P_ThreeIf the signal line for signal transmission is broken,
Based on the magnetic pole position, the output signal of the rotary encoder
Current Electric Angular Rotation Speed and Software Control
To calculate the magnetic pole position using the sample time
Computing means has been configured.

2) One state every 180 ° in electrical angle
Another state different from this alternates adjacently in the circumferential direction
Circle fixed to the rotating shaft of the rotating electric machine
At a mechanical angle of 120 ° relative to the plate in the circumferential direction
And one of the above-mentioned ones, which are arranged in
State and other states, and respond to each state.
U-phase, V-phase and W-phase voltage-based binary signals
Some P_U, P_VAnd P _WThree signals that each send out a signal
Along with a sensor and information indicating forward and reverse rotation of the rotary shaft,
The reference position, which is the transition point between the one state and the other state
Generates a number of pulses according to the rotation angle that subdivides the interval
The disk attached to the rotating shaft and close to the disk
A rotary encoder having a sensor unit disposed as
The combination of the binary signals sent from the three sensors
When detecting the reference position of the rotation axis at every 60 degrees in the air angle
A signal representing the reference position and the rotary encoder
Between adjacent reference positions, which is the output signal of the
And processing the signal representing the relative position to obtain the rotational position of the rotary shaft.
Calculating means for calculating the magnetic pole position based on the position
In the magnetic pole position detecting device for an electric machine, the rotary encoder
If the signal line for transmitting the output signal of the
P _U, P_VAnd P_WReference position of π / 3 interval obtained by signal
Measurement of the position signal and the time during which this reference position signal changes
Current magnetic pole position by the electric angular rotation speed estimated by
The arithmetic means is configured to calculate.

3) One state every 180 ° in electrical angle
Another state different from this alternates adjacently in the circumferential direction
Circle fixed to the rotating shaft of the rotating electric machine
At a mechanical angle of 120 ° relative to the plate in the circumferential direction
And one of the above-mentioned ones, which are arranged in
State and other states, and respond to each state.
U-phase, V-phase and W-phase voltage-based binary signals
Some P_U, P_VAnd P _WThree signals that each send out a signal
Along with a sensor and information indicating forward and reverse rotation of the rotary shaft,
The reference position, which is the transition point between the one state and the other state
Generates a number of pulses according to the rotation angle that subdivides the interval
The disk attached to the rotating shaft and close to the disk
A rotary encoder having a sensor unit disposed as
The combination of the binary signals sent from the three sensors
When detecting the reference position of the rotation axis at every 60 degrees in the air angle
A signal representing the reference position and the rotary encoder
Between adjacent reference positions, which is the output signal of the
And processing the signal representing the relative position to obtain the rotational position of the rotary shaft.
Calculating means for calculating the magnetic pole position based on the position
In the magnetic pole position detecting device for an electric machine, the rotary encoder
If the signal line for transmitting the output signal of the
P _U, P_VAnd P_WReference position of π / 3 interval obtained by signal
Time during which this reference position signal changes based on the
Electric angular rotation speed estimated by measurement and software
Calculate the magnetic pole position using the control sample time
The arithmetic means is configured as described above.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings. The hardware of the embodiment described below is the same as that of the apparatus shown in FIG. 1, and is obtained by devising the function (software) of the arithmetic unit III of FIG. Therefore, this embodiment will be described with reference to FIG. 1 and redundant description will be omitted.

The output signals P _U , P _V , P which are the input signals of the operation unit III when the signal lines of the sensors 3A to 3C are disconnected.
_W is (P _U , P _V , P _W ) ≠ (0,0,0) or (P _U , P _V , P _W ) ≠ (1,1,1). Therefore, the operation unit III determines that P _U , P _V , and P _W are (0, 0, 0)
Alternatively, when it is detected that (1, 1, 1), it is determined that the signal lines of the sensors 3A to 3C are broken, and the position detection is continued by the next processing.

Based on the previous position θold, the current electrical angular rotation speed ω and the control sample time Ts by software
And the current magnetic pole position θ is calculated from θ = θ old + ω · Ts (1). Previous position θol
d is updated every control sample. Note that the electrical angular rotation speed ω can be calculated only with the A-phase or B-phase pulse signals P _A and P _B which are output signals of the sensor units 6a and 6b.

When the signal lines of the sensor sections 6a and 6b are disconnected, the count value between π / 3 is not updated, and the data is held at a certain value. Therefore, when the data is held at a certain value in this way, the arithmetic unit III
It is determined that the wires a and 6b are disconnected, and the position is detected by the following processing. That is, since the position detection at intervals of π / 3 can be performed with the output signals P _U , P _V , and P _W , this data is used as the reference angle θx. Next, the time during which the π / 3 reference signal changes is measured (it can be measured by how many times control sampling has been performed before the signal change), and the current electrical angular rotational speed ω is estimated by the following equation. .omega. = (. pi./3)/(n.Ts) (2) n: Number of samples until signal change The current electric angular rotation speed .omega. The magnetic pole position θ is obtained by the following equation. θ = θx + m · ω · Ts (3) m is the number of samples since the reference angle was changed

When the disconnection of the signal lines of the sensor sections 6a and 6b is detected as described above, the magnetic pole position can be detected by configuring the arithmetic section III as follows. That is, after the electrical angular rotation speed ω is obtained by the above equation (2), the following equation (4) using the control sample time Ts based on the previous position θold as in the case of disconnection of the signal lines of the sensors 3A to 3C is used. ) Is calculated to obtain the magnetic pole position θ. θ = θ old + ω · Ts (4)

According to the device of the present embodiment, the sensors 3A to 3A
Even when the output pulses P _U , P _V , P _W or the A-phase or B-phase pulse signals P _A , P _B are interrupted due to the 3C or the disconnection of the output lines of the sensor units 6 a, 6 b, the detection of the magnetic pole position is continuously detected. I can do it.

[0029]

As described in detail with the above embodiment, according to the present invention, even if one of the pulse signal lines is broken, the magnetic pole position can be detected, and the inverter can be stopped without causing control instability. Nothing.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 shows a disk 2 and sensors 3A and 3 of a reference position detecting unit I.
Explanatory drawing which shows B and 3C.

FIG. 3 shows an output signal of a sensor 3A of a reference position detection unit I and U
FIG. 4 is a waveform diagram showing a relationship between voltage waveforms induced in phase windings.

FIG. 4 is a waveform diagram showing a phase relationship between output pulses P _U , P _V , P _W of sensors 3A, 3B, 3C of a reference position detection unit I and U, V, W phase voltages.

[Explanation of symbols]

 I Reference position detector II Relative position detector III Operation unit 1 Rotary axis 2 Disk

Claims (3)

[Claims] 1. One state per 180 ° electrical angle and this
And another state different from the
A disk fixed to the rotating shaft of a rotating electric machine
At a mechanical angle of 120 ° from each other in the circumferential direction.
The above-mentioned one state according to the rotation of the above-mentioned disk arranged respectively
And three states corresponding to each state
P which is a binary signal based on AC U-phase, V-phase and W-phase voltage
_U, P_VAnd P _WThree sensors that send signals respectively
And information indicating forward and reverse rotations of the rotation axis.
Subdivision between the reference position, which is the transition point between one state and another state
This number of pulses corresponds to the number of rotation angles
The disk attached to the spindle and the disk
And a rotary encoder having a sensor unit, and a binary signal transmitted by the three sensors.
When detecting the reference position of the rotation axis at every 60 degrees in the air angle
A signal representing the reference position and the rotary encoder
Between adjacent reference positions, which is the output signal of the
And processing the signal representing the relative position to obtain the rotational position of the rotary shaft.
Calculating means for calculating the magnetic pole position based on the position
In the magnetic pole position detecting device for an electric machine,₁, P_TwoAnd P_ThreeThe signal line for signal transmission is disconnected.
In this case, the rotary
Current electrical angular rotation speed and software based on the encoder output signal.
Use the software control sample time to determine the magnetic pole position.
The arithmetic means is configured to perform an arithmetic operation.
Magnetic pole position detection device for rotating electric machines. 2. One state per 180 ° electrical angle
And another state different from the
A disk fixed to the rotating shaft of a rotating electric machine
At a mechanical angle of 120 ° from each other in the circumferential direction.
The above-mentioned one state according to the rotation of the above-mentioned disk arranged respectively
And three states corresponding to each state
P which is a binary signal based on AC U-phase, V-phase and W-phase voltage
_U, P_VAnd P _WThree sensors that send signals respectively
And information indicating forward and reverse rotations of the rotation axis.
Subdivision between the reference position, which is the transition point between one state and another state
This number of pulses corresponds to the number of rotation angles
The disk attached to the spindle and the disk
And a rotary encoder having a sensor unit, and a binary signal transmitted by the three sensors.
When detecting the reference position of the rotation axis at every 60 degrees in the air angle
A signal representing the reference position and the rotary encoder
Between adjacent reference positions, which is the output signal of the
And processing the signal representing the relative position to obtain the rotational position of the rotary shaft.
Calculating means for calculating the magnetic pole position based on the position
In the magnetic pole position detecting device of the electric machine, a signal line for transmitting an output signal of the rotary encoder is provided.
If the wire breaks, P _U, P_VAnd P_WObtained by signal
π / 3 interval reference position signal and this reference position signal changes
Electrical rotation speed estimated by measuring the time between
The calculating means is configured to calculate the current magnetic pole position more.
A magnetic pole position detecting device for a rotating electric machine, characterized in that it is formed. 3. One state every 180 ° electrical angle and this
And another state different from the
A disk fixed to the rotating shaft of a rotating electric machine
At a mechanical angle of 120 ° from each other in the circumferential direction.
The above-mentioned one state according to the rotation of the above-mentioned disk arranged respectively
And three states corresponding to each state
P which is a binary signal based on AC U-phase, V-phase and W-phase voltage
_U, P_VAnd P _WThree sensors that send signals respectively
And information indicating forward and reverse rotations of the rotation axis.
Subdivision between the reference position, which is the transition point between one state and another state
This number of pulses corresponds to the number of rotation angles
The disk attached to the spindle and the disk
And a rotary encoder having a sensor unit, and a binary signal transmitted by the three sensors.
When detecting the reference position of the rotation axis at every 60 degrees in the air angle
A signal representing the reference position and the rotary encoder
Between adjacent reference positions, which is the output signal of the
And processing the signal representing the relative position to obtain the rotational position of the rotary shaft.
Calculating means for calculating the magnetic pole position based on the position
In the magnetic pole position detecting device of the electric machine, a signal line for transmitting an output signal of the rotary encoder is provided.
If the wire breaks, P _U, P_VAnd P_WObtained by signal
This reference position signal is based on the reference position signal at intervals of π / 3.
Electric angular speed estimated by measuring the time between changes
Using the degree and the software controlled sample time
The calculating means is configured to calculate a pole position.
A magnetic pole position detecting device for a rotating electric machine.