JP3360946B2 - Control circuit for brushless motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to a brushless motor control system.
In connection with the control circuit, for example, a magnetic bearing type turbo molecular pump or
Brushless motors used for magnetic bearing spindles, etc.
It relates to a control circuit. [0002] 2. Description of the Related Art A brushless motor is usually a semiconductor hole.
Magnetic pole (N pole, S pole) by Hall sensor using element
The position and angle of the Hall sensor
(ON / OFF signal) based on the current of each winding of the motor
Is switched. FIG. 9 shows a control circuit of a conventional brushless motor.
It represents a road. As shown in FIG.
0 has a two-pole permanent magnet, around the rotor 10
Is the rotation angle of the rotor 10 based on the change in the magnetic flux density of the permanent magnet.
Hall sensors 12A, 12A for detecting the degree
B and 12C are arranged at an interval of 120 ° from each other
I have. The Hall sensors 12A, 12B and 12C are
The motor control circuit 14 is connected to
The control circuit 14 includes the Hall sensors 12A, 12B, 12C
Mode, U-phase, V-phase, and W-phase
To switch the current of the windings 16U, 16V, 16W
It has become. [0005] FIG.
Each Hall sensor 12 when the flow switching control is performed
Output waveforms A, B, C of A, 12B, 12C and motor winding
Currents Iu, Iv, Iw,
Pressure V_U←_N, V_V←_N, V_W← _N, And of the generated torque T
It shows the relationship. Note that the voltage V_U←_N, V_V←
_N, V_W←_NAre motor windings 16U, 16U, respectively.
V, U phase, V phase with respect to the midpoint N (see FIG. 1) of 16W,
This is a W-phase voltage. [0006] As shown in FIG.
From the outputs of A, 12B, and 12C, A, B, C
A signal having a waveform as shown in FIG.
Is determined by the rise and fall of each of these signals.
Switch between Iu, Iv and Iw. [0007] However, in general, the hall
Sensors vary in their magnetic flux density detection sensitivity.
And the mounting position also varies slightly.
For this reason, each phase generated when the rotor 10 makes one rotation is used.
The output signals of the rule sensors 12A, 12B and 12C are shown in FIG.
In some cases, uniform intervals may not be obtained as shown in FIG.
You. FIG. 11 shows variations in detection sensitivity and mounting position.
Of the Hall sensors 12A, 12B, 12C
The output waveforms A ', B', C 'and the currents Iu, Iv, Iw
It expresses the relationship. Each Hall sensor 12A, 1
Variation in detection sensitivity and mounting position of 2B and 12C
And, as shown in FIG.
B 'and C' are out of phase from the angular position indicated by the dashed line.
Would. That is, the Hall sensors 12A, 12B, 1
Rise and fall intervals T1 to T of 2C output waveform
6 vary as shown in FIG.
Also, due to this variation, the positions of the currents Iu, Iv, Iw
The phases also vary from phase to phase. [0009] The winding current having a variation in phase
When the rotor 10 is rotated, the torque ripple and the rotor 10
Unfavorable suction force is generated for
With a brushless motor, if vibration or noise occurs during rotation,
There was a problem. In addition, magnetic bearing type turbo molecular pump
Magnetic bearings, like brushless motors
The rotor supported in a non-contact manner by
When rotating with a motor, the sensor output
Due to torque ripple and suction force
Characteristics such as low vibration and low noise of the magnetic bearing
Will be done. Further, in the case of a control type magnetic bearing, the rotor
The magnetic levitation of the rotor corresponding to the displacement (vibration)
Brushless for feedback control of magnet magnetic force
When vibration is applied to the rotor by the motor, the magnetic bearing
Is excited by the control system of
There is.Also, there are two types of detecting the rotation angle of the rotor.
Control circuit for brushless motor with rotation angle detection sensor
In the case of, the low
May not be able to start rotation. Therefore, the present inventionMing isPrevent vibration and noise
To provide a brushless motor control circuit capable of
AndFirst purposeAndThe purpose of the present invention is to determine which corner
Rotation start even if the rotor is stopped
With two rotation angle detection sensors
The second aim is to provide in the control circuit of the brushless motor
Target. [0012] According to the first aspect of the present invention,
Is a three-phase motor winding for rotating the rotor,
The rotation angle of the motor and output a synchronization signal synchronized with the rotation.
Two rotation angle detection sensorsSA2, SB2When,The row
Rotation speed detecting means for detecting the rotation speed of the motor;
Whether the rotation speed detected by the output means is equal to or higher than a predetermined rotation speed
Means for determining the number of revolutions,In the rotation speed determining means
It is determined that the rotation speed of the rotor is equal to or higher than a predetermined rotation speed.
Said,Rotation angle detection sensorSA2Output
From the synchronization signal, the same frequency as three times the rotation speed of the rotor
Synchronization signal generation circuit that generates the expected multiplication synchronization signal
When,The number of revolutions of the rotor is determined by the number of revolutions
If it is determined that the number of turns is less than the number of turns, the rotation angle detection
Motor winding based on the synchronization signals from the sensors SA2 and SB2.
The current of the wire is switched, and the rotation speed of the rotor is set to a predetermined rotation speed.
If it is determined thatMultiplier synchronization signal generation
The respective motors based on the multiplied synchronization signal generated by the circuit.
Winding current control means for switching the current of the winding;
Each of the motor windings switched by the line current control means
A phase adjustment circuit for adjusting the phase of the current of the line,Previous
The rotation angle detection sensors SA2 and SB2 are
The position relative to the line is opposite to the rotation of the rotor
And the phase adjustment circuit is
When the number of rotations of the rotor is equal to or greater than a predetermined
If it is determined that the rotation angle detection sensor
Phase of the current of each motor winding by the
Delaying the first and secondAchieve the goal
You. [0013] [0014] The control circuit of the brushless motor according to claim 1 is provided.
On the road,The rotation angle detection sensors SA2 and SB2 are
Position relative to the feed line
The rotor rotation speed is determined by the rotation speed judgment means.
If it is determined that the rotation speed is less than the specified rotation speed, the rotation angle is detected.
Motor winding based on synchronization signals from sensors SA2 and SB2
Switch the current. This enables the low angle
Even if the motor is stopped, the rotor can start rotating.
Wear. In addition, the rotation speed of the rotor is set to a predetermined
If it is determined that the number of rotations is equal to or greater than
From the synchronization signal output from SA2, the rotation speed of the rotor
Generates a multiplied synchronization signal synchronized to triple the frequency, and
The current of each motor winding is cut off based on the
Change the mounting position of the rotation angle detection sensor
Delay the phase of the motor winding current.Therefore, each mode
The phase variation does not occur in the current of the
Unnecessary suction force and torque ripple are not generated. [0015] [0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a control circuit for a brushless motor of the present invention will be described.
An embodiment of the present invention will be described in detail with reference to FIGS.
I will tell. FIG. 1 shows a brushless motor according to a first embodiment.
Of the control circuit of FIG. The control circuit 2 for the brushless motor of this embodiment
0 is a three-phase rotation for detecting the rotation angle of the rotor 10.
Shift angle detection sensors SA1, SB1, SC1 and rotor 10
Windings 16U, 16V, 16W for rotating the motor
And control the current to motor windings 16U, 16V, 16W
And a motor drive circuit 22 that performs the operation. Rotation angle detection sensors SA1, SB1, SC1
Is 120 ° in the circumferential direction around the rotor 10.
In this embodiment, the rotor 1 is disposed at intervals.
0 by detecting the magnetic flux density of the permanent magnet
A Hall sensor that detects a turning angle is used. This rotation angle detection
The waveforms of the output signals of the sensors SA1, SB1, and SC1 are shown in FIG.
10 are substantially the same as those indicated by A, B and C, respectively.
You. On the other hand, the motor drive circuit 22
4 and 6 transistors forming a three-phase bridge 2
6, 28, 30, 32, 34, 36,
A constant gate signal is applied to each of the transistors 26, 28, 30, 3
By being supplied to the bases of 2, 34 and 36, respectively,
The motor windings 16U, 16V, 16W have U-phase, V
And a three-phase alternating current of a W phase. In FIG. 1, the rotor 10 is shown separately.
Motor windings 16U, 16V and 16W
It is arranged on the outer periphery of the motor 10. Also brushless
The motor control circuit 20 outputs the output of the rotation angle detection sensor SA1.
A multiplication synchronous pulse generation circuit 38 for multiplying the force signal is provided.
I have. The multiplication synchronous pulse generation circuit 38 detects the rotation angle.
Output signal of sensor SA1 (see waveform A in FIG. 10)
From three times the frequency of the rotor 10
In this embodiment, the multiplied synchronization signal is generated.
For example, it is necessary to use the PLL (Phase Locked Loop) method.
Has become. On the other hand, the rotation angle detection sensor SA1 has a rotation
The number detection circuit 40 is also connected. Rotation speed detection circuit 40
Is obtained from the output signal of the rotation angle detection sensor SA1.
And the detected number of rotations is compared with the comparator 42.
To be supplied. The comparator 42 includes:
The value of the predetermined number of revolutions preset in the reference value setting circuit 44
(Reference value) is supplied.
The predetermined rotation speed from the setting circuit 44 and the rotation speed detection circuit 40
Is compared with the detected rotation speed. The brushless motor according to the present embodiment
Control circuit 20 controls the gate drive signal generation circuit 46
Have. The gate drive signal generation circuit 46
Transistors 26, 28, 30, 3 of the
2, 34 and 36, respectively.
The gate signals must be supplied sequentially at a predetermined timing.
And the supply current to the motor windings 16U, 16V, 16W
Is switched. The gate drive signal generation circuit 46
Is the same as that of the rotation angle detection sensors SA1, SB1, and SC1.
Is connected to the initial pulse generation circuit 38 to detect the rotation angle.
From the sensors SA1, SB1, SC1, A, B,
A sensor signal having a waveform as shown by C is a multiplied synchronization pulse.
The generator 38 synchronizes with three times the rotation speed of the rotor 10
The multiplied synchronization signals (see D in FIG. 2) are supplied respectively.
It is supposed to be. Further, the gate drive signal generation circuit 46
Is connected to the comparator 42, and detects the number of rotations.
Detected rotation speed of road 40 and predetermined rotation speed of reference value setting circuit 44
As a result of the comparison, the rotation speed of the rotor 10 is equal to or higher than a predetermined rotation speed.
Signal is supplied.
You. The gate drive signal generation circuit 4 of the present embodiment
In step 6, in accordance with the signal from the comparator 42, the rotation angle
Sensor signals from detection sensors SA1, SB1, SC1
Of the multiplied synchronization signal from the multiplied synchronization pulse generation circuit 38
Control of the motor drive circuit 22 based on either one
It is supposed to do. That is, the rotation speed of the rotor 10 is
A signal indicating that the number is less than the number is supplied from the comparator 42.
In this case, the rotation angle detection sensors SA1, SB1, S1
In synchronism with the sensor signal from C1,
Is generated, a multiplied synchronization pulse is generated.
The motor drive circuit is synchronized with the multiplication synchronization signal from the circuit 38.
A gate signal to the road 22 is output. Next, the operation of the embodiment configured as described above.
Will be described. In this embodiment, the rotation speed of the rotor 10
Operation is different between when
Therefore, hereinafter, the rotation speed including the start time is less than the predetermined rotation speed.
The rotation of the rotor 10 at low speed, when the rotation speed is equal to or higher than a predetermined rotation speed.
In each case, the rotation of the rotor 10 is assumed to be a steady rotation.
Will be described. (Low-speed rotation) When the rotation of the rotor 10 is started
Is the rotation of the rotor 10 detected by the rotation speed detection circuit 40.
Since the number is 0, the multiplied synchronization pulse generation circuit 38
No periodic sensor signal is supplied.
Does not occur. Also, the gate drive signal generation circuit 46
Is based on the rotation speed of the rotor 10 from the comparator 42.
It is less than the predetermined number of revolutions set in the value setting circuit 44
Is supplied. Thus, the gate drive signal generation circuit
46 is from the rotation angle detection sensors SA1, SB1, SC1
Control of the motor drive circuit 22 based on the three sensor signals
I do. That is, as shown in FIGS.
Sensor signals of rotation angle detection sensors SA1, SB1, SC1
A predetermined gate signal in synchronization with the rise of
Transistors 26, 28, 30, 32, 34, 36
Pay. Thereby, motor windings 16U, 16V, 16
W has currents as shown by Iu, Iv, and Iw in FIG.
Is supplied, and a rotational torque as shown by T in FIG.
Then, the rotor 10 is rotated. (During steady rotation) The rotation speed of the rotor 10 increases.
The speed is higher than a predetermined rotation speed set in the reference value setting circuit 44.
The gate drive signal is generated from the comparator 42.
In the forming circuit 46, the rotation speed of the rotor 10 is equal to or higher than a predetermined rotation speed.
Is supplied. On the other hand, in the multiplication synchronous pulse generation circuit 38,
Synchronized with the rotation of the rotor 10 from the rotation angle detection sensor SA1
The periodic sensor signal (see FIG. 10A) is supplied.
From this sensor signal, it is equal to three times the rotation speed.
The expected multiplication synchronization signal is generated and the gate drive signal
It is supplied to the forming circuit 46. The gate drive signal generation circuit 46
When the rotation speed of the rotor 10 is equal to or less than the predetermined rotation speed from the
Since the signal indicating that it has risen is received, the rotation angle detection
Instead of the signals from the sensors SA1, SB1, SC1,
Based on the multiplied synchronization signal from the double synchronization pulse generation circuit 38,
The control of the motor drive circuit 22 is performed. That is, multiplication synchronization
Motor drive circuit synchronized with signal rise and fall
22 transistors 26, 28, 30, 32, 34,
36, a predetermined gate signal is sequentially supplied. FIG. 2 shows a gate drive signal generation circuit 46.
Control of the motor drive circuit 22 by the
Currents Iu, I supplied to lines 16U, 16V, 16W
v and Iw. As shown in this figure,
Multiplied synchronization signal D generated by double synchronization pulse generation circuit 38
Is the sensor signal A1 of the rotation angle detection sensor SA1.
It has three times the frequency. The multiple synchronization signal D is a multiple synchronization pulse.
Since the signal is generated by the generation circuit 38,
Of the sensor signals A ', B', and C 'shown in FIG.
In addition, signal characteristics caused by the characteristics and mounting position of individual sensors
No variation occurs. Therefore, in FIG.
As shown by T6, the cycle of the multiplied synchronization signal D is
Equally spaced. In this embodiment, the gate drive signal generation circuit
The path 46 has a rising edge in the equally-spaced multiplied synchronization signal D.
Control of the motor drive circuit 22 in synchronization with the
As shown in FIG. 2, the motor windings 16U, 16U
V, 16W currents Iu, Iv, Iw also vary in waveform
Does not occur. Therefore, torque ripple and unnecessary suction force
Without any vibration and noise.
Can be rotated. As described above, in this embodiment, the rotation
From the sensor signal A1 of the angle detection sensor SA1, a multiple synchronization signal
No. D is generated.
Brushless using the angle detection sensors SA1, SB1, SC1
A motor control circuit 20.
Configuration can be simplified. Further, as described above, the rotor 10 is stopped.
In the state, the multiplication synchronous pulse generation circuit 38
In this embodiment, since the double synchronization signal cannot be obtained,
The rotation angle detection sensors SA1, SB1, SC
The rotor 10 is started using the three sensor signals 1
Like that. Therefore, the torque generated at startup is large.
And the rotor 10 can be smoothly started to rotate.
You. Further, according to the present embodiment capable of low vibration and low noise,
Bearings using brushless motor control circuit 20
When rotating the rotor supported by the
Vibration does not easily occur, so the output from the magnetic bearing is small.
Operation efficiency is improved. Next, a second embodiment will be described.
Will be explained. In addition, about the structure similar to 1st Example.
Are denoted by the same reference numerals, and a detailed description thereof will be omitted as appropriate.
And FIG. 3 shows a brushless model according to a second embodiment.
2 shows a main configuration of a data control circuit 50. Book
The control circuit 50 of the brushless motor in the embodiment
Rotation angle detection sensors for detecting the rotation angle of the
Sensors SA2 and SB2. These rotation angle detection sensors SA2, SB2
Are connected to the gate drive signal generation circuit 46, respectively.
The rotation angle detection sensor SA2 further generates a multiple synchronization pulse.
It is connected to a raw circuit 38 and a rotation speed detection circuit 40.
The multiplication synchronous pulse generation circuit 38 includes a rotation angle detection sensor SA.
Synchronized to 3 times the rotation speed of rotor 10 from 2 sensor signals
Generates the multiplied synchronization signal and generates the gate drive signal.
The air is supplied to the road 46. The gate drive signal generation circuit 46 has a first
As in the embodiment of FIG.
At the time of low-speed rotation, the rotation angle detection sensors SA2 and SB2
Drive control based on sensor signals from
Sometimes a multiplied synchronization signal from a multiplied synchronization pulse generation circuit 38
Is performed based on the drive control. In this embodiment, the rotation angle detection sensor SA2
Is opposite to the rotation angle detection sensor SB2 in FIG.
It is installed at a position that is rotated 120 degrees clockwise,
The relative positional relationship between the two is based on the rotation in the first embodiment.
This is the same as the angle detection sensors SA1 and SB1. However, in this embodiment, it is not shown.
Are the rotation angles with respect to the motor windings 16U, 16V, and 16W.
The relative position of the detection sensors SA2 and SB2
It is shifted by 30 ° in the direction opposite to the 0 rotation. FIG.
Examples of mounting angles of the shift angle detection sensors SA2 and SB2
It is a mere expression. In this embodiment, the rotation angle detection sensor SA2,
As shown in FIG. 4 (A), SB2 has a row indicated by an arrow R.
At a position rotated 30 ° in the direction opposite to the direction of rotation of the
Installed. On the other hand, although not shown, the motor winding
16U, 16V, 16W are located at the same positions as in the first embodiment.
Since they are provided, the rotation angle detection sensors SA2 and SB2
Mounting position of the motor windings 16U, 16V, 16W
It is shifted by 30 °. The rotation angle detection sensors SA2 and SB2
The positions are the same as in the first embodiment, and the motor windings 16U, 1
The direction of 6V, 16W is determined by the direction of rotation of the rotor 10 (arrow
(In the direction of mark R) by 30 °, the relative positions of the two
May be shifted. In this embodiment, the rotation angle detection sensor is used.
The positions of the sensors SA2 and SB2 are determined by the rotation angle detection cells of the first embodiment.
It is shifted 30 ° from the position of sensors SA1 and SB1
Is for the following reason. That is, the rotation angle detection is performed in the same manner as in the first embodiment.
The outgoing sensors SA2 and SB2 are arranged at the positions shown in FIG.
Drive at low rotation using these sensor signals.
In the control, the motor windings 16U, 16V, 16W
The generated torque becomes zero depending on the rotational position of the rotor 10.
This is because it may be. FIG. 5 is a view showing the state where the lens is mounted at the position shown in FIG.
Based on the detected rotation angle detection sensors SA2 and SB2.
Then, the gate drive signal generation circuit 46 drives the motor.
Winding current, voltage and generation when controlling the circuit 22
It is a representation of torque. As shown in FIG.
When the turning angle detection sensors SA2 and SB2 are arranged,
At the time of low-speed rotation performed based on the sensor signals A2 and B2
In the drive control, the point O (0 °) and the point P (1
80 °), the generated torque T becomes zero.
Would. Therefore, the rotor 10 stops at this angular position.
When the rotor 10 is stopped, the rotor 10 is started to rotate.
The inconvenience of not being able to do it occurs. In this embodiment,
In order to eliminate such an angular position where the torque T becomes zero,
Shift the mounting positions of the turning angle detection sensors SA2 and SB2
I have. FIG. 6 is a view showing the state where the light source is mounted at the position shown in FIG.
Based on the detected rotation angle detection sensors SA2 and SB2.
Then, the gate drive signal generation circuit 46 drives the motor.
Winding current, voltage and generation when controlling the circuit 22
It is a representation of torque. As in the present embodiment, FIG.
The rotation angle detection sensors SA2 and SB2 are located at the positions shown in FIG.
When attached, these sensor signals A2, B2
In the drive control at the time of low-speed rotation using
As described above, there is no angular position where the torque T becomes zero. Therefore,
Even if the rotor 10 is stopped at the angular position
Can be started to rotate. However, in this case, the rotation angle detection sensor SA2
Since the phase of the sensor signal A2 advances by 30 °, the multiplication synchronous pulse
Phase of the multiplied synchronization signal generated in the
Also advance that much. Therefore, the gate drive signal
The forming circuit 46 performs the motor driving circuit 2 based on the multiplied synchronization signal.
2 during steady rotation to control the phase of the multiplied synchronization signal.
The phases of the winding currents Iu, Iv, Iw are shifted
I will. Therefore, the control of the brushless motor of this embodiment is
The control circuit 50 is driven at the time of steady rotation using the multiplied synchronization signal.
In the control, the gate drive signal generation circuit 46
The phase of the gate signal supplied to the
Delay (30 °) by the displacement of the mounting position of detection sensor SA2
And a phase adjustment circuit 52 for adjusting the phase. With this phase adjusting circuit 52,
In this case, the change in the winding current during steady rotation is the same as in FIG.
It is the same as that shown in FIG. The rotation angle detection sensor S
A2 and SB2 may be attached to other positions. example
For example, as shown in FIG.
SA2 is the rotation angle detection sensor SA1 in the first embodiment.
And the other rotation angle detection sensor SB2
Set at a position rotated 90 ° from the rotation angle detection sensor SA2.
May be attached. FIG. 7 is a view showing the state where the lens is mounted at the position shown in FIG.
Based on the detected rotation angle detection sensors SA2 and SB2.
Then, the gate drive signal generation circuit 46 drives the motor.
Winding current, voltage and generation when controlling the circuit 22
It is a representation of torque. Rotation angle detection sensor SA2,
Even if the SB2 is mounted at the position shown in FIG.
Drive control based on these sensor signals
Is the angle at which the generated torque T becomes zero, as shown in FIG.
There is no degree position. In this case, the rotation angle detection sensor
Since the phase of the sensor signal A2 of the sensor SA2 does not deviate,
There is no need to provide the adjustment circuit 52, and the
The configuration can be simpler than the configuration. The rotation angle is detected at the position shown in FIG.
The sensors SA2 and SB2 are arranged, and the points SA and P in FIG.
By providing a mechanism so that the data 10 does not stop,
Inability to start the motor 10 may be prevented. For example, point O or point
A magnetic pole that repels the permanent magnet of rotor 10 is located at position P
So that the rotor 10 does not stop at the rotation position.
You. Next, a third embodiment will be described. What
Note that the same configuration as the first and second embodiments is the same.
And a detailed description thereof will be omitted as appropriate.
You. FIG. 8 shows the control of the brushless motor according to the third embodiment.
2 shows a main configuration of the control circuit 60. As shown in this figure, in this embodiment, one
Only the rotation angle detection sensor SA3 of FIG.
Installed. This rotation angle detection sensor SA3 is
Gate drive signal generation circuit 46 and multiplication synchronous pulse generation
Circuit 38 and a rotation speed detection circuit 40,
A sensor signal is supplied to these. Further, control of the brushless motor according to the present embodiment.
The circuit is gated regardless of the rotational position of the rotor 10.
Supplying a signal of a predetermined frequency to the live signal generation circuit 46
As a result, the mode is generated by the gate drive signal generation circuit 46.
Self-starting frequency generation for forcibly driving the data drive circuit 22
A circuit 62 is provided. That is, in this embodiment, the rotation of the rotor 10
The means for detecting the turning angle is only the rotation angle detecting sensor SA3.
Therefore, when the rotation of the rotor 10 is started, its angular position cannot be determined.
No. Therefore, the sensor signal of the rotation angle detection sensor SA3 is
Control of the winding current based on the
And cannot start rotation. Therefore, in this embodiment,
The frequency generation circuit 62 is a gate drive signal generation circuit 46
Signal of a predetermined frequency to forcibly cut off the winding current.
By changing, the rotor 10 is started like a pulse motor.
It has become so. Other configurations and operations other than those at the time of starting are described in the first section.
This is the same as in the second embodiment. In this embodiment, the rotation angle
Since the number of detection sensors is smaller than in other embodiments,
Cost can be reduced. Each of the above embodiments
Then, the rotation angle detection sensors SA1, SB1, SC1, SA
Hall sensors were used as 2, SB2 and SA3
However, other sensors may be used. For example, Inductan
A magnetic conversion type magnetic sensor may be used. However, on this occasion
In this case, a rotation position detecting plate formed of a magnetic material
Install. In addition, eddy current sensors, MR element sensors,
Rotation angle of the rotor 10 using a photo sensor, a resolver, etc.
May be detected. In each of the above embodiments, the multiplication synchronous pulse
The rotation generating circuit 38 rotates the rotor 10 by the PLL method.
A multiplied synchronization signal synchronized to three times the number was generated.
The synchronization signal may be generated by the following method. Furthermore, three phases
Other, for example, two-phase or four-phase brushless motor
The present invention can also be applied to However, 2
In the case of the phase, the multiplication synchronous pulse generation circuit 38 outputs the rotation angle
Twice the rotation speed of the rotor 10 from the sensor signal of the detection sensor
Signal synchronized to the frequency of the four-phase brushless motor
Generates a signal synchronized with the frequency of 4 times the rotation speed
To do it. [0061] According to the control circuit of the brushless motor of the present invention,
According toThe rotation angle detection sensors SA2 and SB2 are
Position relative to the feed line
The rotor rotation speed is determined by the rotation speed judgment means.
If it is determined that the rotation speed is less than the specified rotation speed, the rotation angle is detected.
Motor winding based on synchronization signals from sensors SA2 and SB2
The rotor stops at which angle position
Even if it does, the rotor can be started to rotate. Ma
In addition, the rotation speed of the rotor is not less than a predetermined
Is determined, the rotation angle detection sensor SA2 determines
From the output synchronization signal, the frequency is three times the rotation speed of the rotor.
Generates a multiplication synchronization signal synchronized with the wave number and generates the multiplication signal.
Switch the current of each motor winding based on the synchronization signal,
Each motor is wound by the displacement of the rotation angle detection sensor mounting position.
Since the current phase of the feeder is delayed,Torque ripple and b
No unnecessary suction force is applied to the motor to prevent vibration and noise
can do.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing a control circuit of a brushless motor according to a first embodiment of the present invention. FIG. 2 is a timing chart showing winding current, voltage, generated torque, and the like when a rotor is rotated using the same circuit. FIG. 3 is an explanatory diagram showing a control circuit of a brushless motor according to a second embodiment of the present invention. FIG. 4 is an explanatory diagram showing an example of a mounting position of a rotation angle detection sensor provided in the circuit. FIG. 5 is a timing chart showing winding current, voltage, generated torque, and the like when a rotation angle detection sensor is mounted at the position shown in FIG. 4 (B). FIG. 6 is a timing chart showing winding current, voltage, generated torque, and the like when a rotation angle detection sensor is mounted at the position shown in FIG. 4 (A). FIG. 7 is a timing chart showing winding current, voltage, generated torque, and the like when a rotation angle detection sensor is attached to the position shown in FIG. 4C. FIG. 8 is an explanatory diagram showing a control circuit of a brushless motor according to a third embodiment of the present invention. FIG. 9 is an explanatory diagram showing a control circuit of a conventional brushless motor. FIG. 10 is a timing chart showing an example of a winding current, a voltage, a generated torque, and the like when a rotor is rotated using the same circuit. FIG. 11 is a timing chart showing another example of the winding current, voltage, generated torque, and the like when the rotor is rotated using the same circuit. [Description of References] 10 Rotor 16U, 16V, 16W Motor winding 20, 50, 60 Brushless motor control circuit 22 Motor drive circuit 24 DC power supply 26, 28, 30, 32, 34, 36 Transistor 38 Multiplier synchronous pulse generation circuit 40 rotation speed detection circuit 42 comparator 44 reference value setting circuit 46 gate drive signal generation circuit 52 phase adjustment circuit 62 self-start frequency generation circuit

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Claims (1)

(57) [Claim 1] A three-phase motor winding for rotating a rotor, and two rotation angle detection sensors for detecting a rotation angle of the rotor and outputting a synchronization signal synchronized with the rotation. SA2, SB2, rotation speed detection means for detecting the rotation speed of the rotor, and the rotation speed detected by the rotation speed detection device is equal to or less than a predetermined rotation speed.
Rotation speed determining means for determining whether the rotation speed is above or not , and wherein the rotation speed of the rotor
If it is determined that the above is satisfied, the rotation angle detection sensor
From synchronization signal output from the SA2, and multiplied synchronizing signal generating circuit for generating a multiplied synchronized signal synchronized with three times the frequency of the rotational speed of the rotor, the predetermined rotational speed rotational speed of the rotor at the rotation speed determining means
The rotation angle detection sensor
Based on the synchronization signal from SA2 and SB2,
The current is switched, and the rotation speed of the rotor is equal to or higher than a predetermined rotation speed.
When it is determined that the currents of the motor windings are switched based on the multiple synchronization signal generated by the multiple synchronization signal generation circuit, the current is switched by the winding current control means. A phase adjustment circuit for adjusting the phase of the current of each motor winding, wherein the rotation angle detection sensors SA2 and SB2
The position relative to the feed line is opposite to the rotation of the rotor
The phase adjustment circuit is mounted on the rotor by the rotation speed determining means.
If it is determined that the rotation speed is equal to or higher than the predetermined rotation speed,
Each of the rotation angle detection sensors is displaced by an amount corresponding to the displacement of the mounting position.
A brushless motor control circuit, which delays the phase of a motor winding current .