JPH10313585A - Operation control device of brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent out-of-step on migration, by verifying the pattern of a rotor position detection signal when the final commutation signal pattern of a synchronous operation mode is outputted before migrating from the synchronous mode to a rotor position detection operation mode, and by sending an appropriate commutation signal to a rotor position. SOLUTION: In a rotor position detection operation mode on normal operation, a brushless motor 3 is operated by a commutation signal being generated via a rotor position detection means 6. On activation, the commutation signal is given with a low frequency as a synchronous operation mode and the motor 3 is forcibly rotated. On migration from the synchronous operation mode to the rotor position detection operation mode, a final commutation signal pattern is outputted, the synchronous operation mode is ended, and the rotor position detection signal is read. Then, a specific commutation signal that should be outputted by the pattern of the rotor position detection signal is determined by a position signal pattern judgment means 10, thus migrating to the operation mode relatively normally and starting a device stably and quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control device for a brushless motor, and more particularly, to detecting a relative position between a magnet rotor and an armature winding based on an induced voltage induced in an armature winding. The present invention relates to a method of activating a brushless motor operation control device that operates based on a position detection signal.

[0002]

2. Description of the Related Art A brushless motor usually requires a detector for detecting the magnetic pole position of its rotor. However, if it is difficult to use the magnetic pole position detector, the magnetic pole position detector is omitted. A method of generating a commutation signal of a motor based on a voltage signal induced in an armature winding has been used.

However, since no induced voltage is generated in the stop state, a predetermined commutation signal is output and a rotating magnetic field is generated to perform a synchronous operation until the rotational speed at which the position can be detected. A commutation signal is generated by detection and operation is performed.

An operation control device for such a brushless motor is disclosed, for example, in Japanese Patent Application Laid-Open No. 3-239188.

Hereinafter, the above-mentioned conventional operation control device for a brushless motor will be described with reference to the drawings.

FIG. 7 is a block diagram of a conventional operation control device for a brushless motor. FIG. 8 is a timing chart of an operation mode of a conventional operation control device for a brushless motor. FIG. 9 is a flowchart of the conventional control.

In FIG. 7, reference numeral 1 denotes a direct current, and 2 denotes a semiconductor switching element group, which comprises six transistors TRu + to TRw- and six diodes each connected in antiparallel.

Reference numeral 3 denotes an armature winding 4 and a magnet rotor 5 connected in a three-phase manner by a brushless motor. Reference numeral 6 denotes a rotor position detecting means, which comprises three filters 6-1 to 6-3 and a comparator group 6-4. Reference numeral 7 denotes a commutation signal generating means, which performs a logical operation on the rotor position detection signals 6X, 6Y, and 6Z output from the rotational position detection means 6 to perform a commutation signal 7U + of the transistors of the semiconductor switch element group 2.
7W-, and switches six transistors TRu + to TRw-, respectively.

Reference numeral 8 denotes a pattern comparing means which compares the rotor position detection signals 6X to 6Z with the specific pattern (L, L, H) and determines that (6X, 6Y, 6Z) = (L, L, H). Output to the commutation signal generating means.

The operation of the operation control device for a brushless motor configured as described above will be described with reference to FIGS.

First, in a rotor position detecting operation mode during normal operation, a voltage signal induced in the armature winding 4 is detected, and the voltage signal obtained by converting the voltage signal by the rotor position detecting means 6 is obtained. The brushless motor 3 is operated by the commutation signal generated from the slave position detection signal.

The rotor position detection signals of 6X to 6Z shown in FIG. 8 are taken into the commutation signal generating means 7, and logical operations are performed to generate commutation signals of 7U + to 7W-. The transistors of the semiconductor switching element group 2 are switched by these commutation signals, so that the brushless motor 3 continuously generates a rotational torque.

On the other hand, when the brushless motor is stopped, no induced piezoelectricity is generated in the armature winding 4, so at the time of startup (step 1), the commutation signals of 7U + to 7W- in FIG. And the brushless motor 3 is forcibly rotated. Due to this rotation, an induced voltage is generated in the armature winding 4 and is converted by the rotor position detecting means 6 to obtain rotor position detection signals 6X to 6Z in FIG.

Accordingly, the cycle of the commutation signal is accelerated until the rotor position detection signal is sufficiently established, and when the rotor position detection signal is sufficiently established, the pattern comparing means 8
The commutation signal generating means takes in the output of (1) and waits. When the fifth pattern of the commutation signal is output as the synchronization signal (step 2), the rotor position detection signal is equivalent to the output of the sixth pattern of the commutation signal (6X, 6Y, 6Z) =
(L, L, H) (step 3).

The instantaneous pattern comparing means 8 outputs to the commutation signal generation means 7 (step 4), whereby the commutation signal generation means 7 switches from the synchronous operation mode to the rotor position detection operation mode. Thereafter, at the timing when 6X rises next due to the rotation of the brushless motor (step 5), the commutation signals 7U + to 7W- become the first pattern (step 6), and thereafter the commutation signals are sequentially generated based on the rotor position detection signals. It is generated and operated in the rotor position detection mode (step 7).

[0016]

However, in the synchronous operation mode, when the motor load changes, the operation load angle between the armature winding and the magnet rotor becomes unstable. Therefore, in the above-described conventional configuration, when the motor load becomes large and the rotor does not follow the magnetic field of the armature winding due to the forced commutation signal, the synchronous operation mode sets the output of the final commutation signal to the sixth pattern. , The following rotor position detection signal pattern is uniquely assumed to be (6X, 6Y, 6Z) = (L, L, H). Since the first pattern is output for the first time, if the synchronization is lost, the commutation is not performed, the output remains the same, and the step-out stops.

Further, when the load is small, the phase of the rotor advances with respect to the rotating magnetic field of the armature winding, and the step-out stops. Further, at the time of transition to the position detection operation mode, the magnet rotor is demagnetized depending on the rotor position and the amount of current.

In order to smoothly shift to the position detection operation mode, it is necessary to sufficiently establish a rotor position detection signal. It was necessary to operate in the synchronous operation mode.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a brushless motor operation control device capable of preventing a step-out when shifting from a synchronous operation mode to a position detection operation mode.

[0020]

SUMMARY OF THE INVENTION To achieve this object, the present invention provides a method for outputting a final commutation signal pattern in a synchronous operation mode, and then outputting a position signal when shifting from the synchronous operation mode to the rotor position detection operation mode. The rotor position is confirmed from the pattern of the rotor position detection signal by the pattern determination means,
By outputting an appropriate commutation signal for the rotor position, the step-out stop is reduced.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a brushless motor having a multi-phase armature winding connected to a neutral ground and a magnet rotor, a DC power supply, and energizing a current to the armature winding. A semiconductor switching element group to be interrupted, and a position detecting means for detecting a relative position of the magnet rotor with respect to the armature winding by a voltage signal induced in the armature winding by rotation of the magnet rotor. And a rotor position detection operation mode for operating the brushless motor by a commutation signal generated from a rotor position detection signal obtained by conversion by the position detection means, and until the rotor position detection signal is established. Has a synchronous operation mode in which the brushless motor is driven by forcibly outputting a commutation signal to generate a rotating magnetic field, and forcibly outputting a commutation signal during the synchronous operation mode. A commutation signal generating means for generating a commutation signal based on an output of the rotor position detection means during the rotor position detection operation mode, and outputting a final commutation signal pattern in the synchronous operation mode; Position signal pattern determination means for confirming the pattern of the rotor position detection signal and determining a specific commutation signal to be output based on the pattern of the position detection signal when the mode shifts to the rotor position detection operation mode. It has.

After the final commutation signal pattern in the synchronous operation mode is output, when the synchronous operation mode shifts to the rotor position detection operation mode, the position signal pattern determining means determines the rotor position detection signal from the rotor position detection signal pattern. By confirming the position and outputting a specific commutation signal to the rotor position, the step-out stop can be reduced, and the demagnetization of the magnet rotor can be reduced. In addition, stable startup can be performed in a short period of time.

The position signal pattern determining means stops outputting the commutation signal when the conduction state of the semiconductor switch element group by the commutation signal is determined to be in the short-circuit mode. By performing the restart, it is possible to prevent damage to the semiconductor switch element group, blowout of the fuse of the primary power supply, and the like.

Further, when the position signal pattern determining means determines that the energized state of the semiconductor switching element group by the commutation signal is the short-circuit mode, the commutation signal generating means maintains the output of the commutation signal as it is, By confirming the pattern of the rotor position detection signal again when the pattern of the position detection signal changes, the operation can be continued without stopping even if the magnet rotor is out of synchronization in the synchronous operation mode.

Further, when the position signal pattern determining means determines that the energized state of the semiconductor switch element group by the commutation signal is the short-circuit mode, the output of the commutation signal is stopped. By restarting the motor with the generated torque larger than the previous time, it is possible to reduce the loss of synchronism and start the motor when the load torque of the motor is large.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a brushless motor operation control device according to the present invention will be described below with reference to the drawings. The same components as those in the related art are denoted by the same reference numerals, and detailed description thereof will be omitted.

(Embodiment 1) FIG. 1 is an overall configuration diagram of a brushless motor operation control device according to Embodiment 1 of the present invention. FIG. 2 is a timing chart of the operation mode of the embodiment, and 3 is a flowchart of the embodiment.

In the figure, reference numeral 1 denotes a DC current, and 2 denotes a semiconductor switching element group, which comprises six transistors TRu + to TRw- and six diodes each connected in anti-parallel. Reference numeral 3 denotes an armature winding 4 and a magnet rotor 5 connected in a three-phase manner by a brushless motor. Reference numeral 6 denotes a rotor position detecting means, which comprises three filters 6-1 to 6-3 and a comparator group 6-4.

Reference numeral 9 denotes a commutation signal generating means, which is a rotor position detection signal 6X, 6Y,
By performing a logical operation on 6Z, commutation signals 7U + to 7W- of the transistors of the semiconductor switch element group 2 are generated, and the six transistors TRu + to TRw- are respectively switched.

Numeral 10 is a position signal pattern determining means for determining a specific commutation signal to be output based on the pattern of the position detection signal of the magnet rotor.

The operation of the operation control device for a brushless motor configured as described above will be described.

First, in the rotor position detection operation mode during normal operation, a voltage signal induced in the armature winding 4 is detected, and this voltage signal is converted by the rotor position detection means 6 to obtain 1 The brushless motor 3 is operated by a commutation signal generated from the rotor position detection signal.

The rotor position detection signals of 6X to 6Z shown in FIG. 2 are taken into the commutation signal generating means 9 and logical operation is performed to generate 9U + to 9W- commutation signals. The transistors of the semiconductor switching element group 2 are switched by these commutation signals, so that the brushless motor 3 continuously generates a rotational torque.

On the other hand, since no induced voltage is generated in the armature winding 4 while the brushless motor is stopped, the commutation signals of 9U + to 9W- in FIG. The motor 3 is forcibly rotated.
Due to this rotation, an induced voltage is generated in the armature winding 4 and is converted by the rotor position detecting means 6 so that 6X in FIG.
To 6Z rotor position detection signals are obtained.

In FIG. 3, after outputting the first pattern in step 101, the cycle of the commutation signal is accelerated to shift from the synchronous operation mode to the rotor position detection operation mode. , The commutation signal sequentially output from the first pattern outputs a fifth pattern. After that, after outputting the sixth pattern in step 102, the synchronous operation mode is ended. In step 103, the rotor position detection signal 6X
6Z.

Here, when the synchronization of the magnet rotor 5 is shifted, (6X, 6Y, 6Z) = (H, L, H) is not always satisfied.

Therefore, a specific commutation signal to be output is determined by the position signal pattern determination means 10 based on the pattern of the rotor position detection signal.

In steps 104 to 109, the output pattern of the commutation signal to be dealt with in the obtained six patterns of rotor position detection signals
It is determined in step 115 from 0.

Thereafter, the brushless motor 3 is operated in the rotor position detection operation mode, the n-th pattern is output after outputting the (n-1) -th pattern, and the first pattern is output after outputting the n-th pattern.
The pattern is output sequentially and cyclically again from the pattern.

Thus, even when the motor load changes and the magnet rotor is out of synchronization, it is possible to relatively normally shift from the synchronous operation mode to the rotor position detection operation mode.
In addition, stable startup can be performed in a short period of time.

(Embodiment 2) FIG. 4 is a flowchart of Embodiment 2 of the present invention. In FIG. 4, after outputting the first pattern in step 201, acceleration is performed as in the first embodiment,
After outputting the sixth pattern in step 202, the rotor position signal is read in step 203. In steps 204 to 209, the position signal pattern determining means determines a specific commutation signal to be output based on the pattern of the rotor position detection signal.

Here, when the commutation signal is switched to the second, third, and fourth pattern outputs after the sixth pattern is output, the semiconductor switching element group 2 is in the short-circuit mode.
For example, when switching from the sixth pattern to the second pattern,
TRw + and TRw- are momentarily turned ON. This is due to the response delay of the semiconductor switching element. Therefore, in the case of such a short-circuit mode, the operation is temporarily stopped as shown in step 221, restarted again, and starts from step 201.

Thus, even when the motor load changes and the magnet rotor loses synchronization, it is possible to relatively normally shift from the synchronous operation mode to the rotor position detection operation mode. Damage and blowout of a fuse (not shown) on the primary side of the power supply can be prevented.

(Embodiment 3) FIG. 5 is a flowchart of Embodiment 3 of the present invention. In FIG. 5, after outputting the first pattern in step 301, the same processing as in the first embodiment is performed.

Then, in step 303, the rotor position signal is read. Step 304 to step 30
In step 9, the position signal pattern determination means 10 determines a specific commutation signal to be output based on the pattern of the rotor position detection signal. At this time, in the short-circuit mode shown in the second embodiment, the commutation signal generating means 9 keeps the output of the commutation signal as it is, and when the pattern of the position detection signal changes again, the commutation signal generation means 9 outputs the commutation signal again. Check the pattern. Thereby, even when the magnet rotor 5 is out of synchronization in the synchronous operation mode, the operation can be continued without stopping.

Further, it is possible to normally shift from the synchronous operation mode to the rotor position detection operation mode, thereby preventing damage to the semiconductor switching element group 2 and blown fuse (not shown) on the primary side of the power supply. it can.

(Embodiment 4) FIG. 6 is a flowchart of Embodiment 4 of the present invention. In FIG. 6, after outputting the first pattern in step 401, the same processing as in the second embodiment is performed.
Here, in the short-circuit mode in steps 405, 406, and 407, the operation is temporarily stopped, the generated torque is increased (for example, the duty ratio is increased) according to the pattern of the rotor position detection signal, and the operation is restarted. Start with. In particular, when the short-circuit mode is set, it is considered that the motor load is large. Therefore, by increasing the generated torque in this way and restarting the motor, it is possible to reduce the loss of synchronism even when the motor load is large. Can start.

In the above embodiment, the brushless motor having the three-phase armature windings is used, and the driving waveform is set to six patterns. However, the present invention is not limited to this condition.

The rotor position detecting means comprises a filter and a comparator. However, any other means may be used as long as the relative position of the magnet rotor can be obtained from the induced voltage.

[0050]

As described above, the present invention provides a brushless motor having a multi-phase armature winding connected to a neutral point ground and a magnet rotor, a DC power supply, and a power supply to the armature winding. A relative position of the magnet rotor with respect to the armature winding is detected by a semiconductor switching element group that conducts and interrupts a current, and a voltage signal induced in the armature winding when the magnet rotor rotates. A rotor position detection operation mode for operating the brushless motor by a commutation signal generated from a rotor position detection signal obtained by conversion by the position detector and a rotor position detection signal obtained by the position detector is established. A synchronous operation mode in which a commutation signal is forcibly output to generate a rotating magnetic field to drive the brushless motor until the synchronous operation mode is performed. And a commutation signal generating means for generating a commutation signal based on the output of the rotor position detection means during the rotor position detection operation mode. After the output, at the time of transition from the synchronous operation mode to the rotor position detection operation mode, the position where the pattern of the rotor position detection signal is confirmed and the specific commutation signal to be output is determined based on the pattern of the position detection signal. Signal pattern determining means.

After the final commutation signal pattern in the synchronous operation mode is output, when the synchronous operation mode shifts to the rotor position detection operation mode, the position signal pattern judging means determines the rotor position detection signal from the rotor position detection signal pattern. By confirming the position and outputting a specific commutation signal to the rotor position, the step-out stop can be reduced, and the demagnetization of the magnet rotor can be reduced. In addition, stable startup can be performed in a short period of time.

Further, when the position signal pattern determining means determines that the energized state of the semiconductor switch element group by the commutation signal is the short-circuit mode, the output of the commutation signal is stopped. By performing the restart, it is possible to prevent damage to the semiconductor switch element group, blowout of the fuse of the primary power supply, and the like.

Further, when the position signal pattern determining means determines that the conduction state of the semiconductor switching element group by the commutation signal is the short-circuit mode, the commutation signal generating means maintains the output of the commutation signal as it is, By confirming the pattern of the rotor position detection signal again when the pattern of the position detection signal changes, the operation can be continued without stopping even if the magnet rotor is out of synchronization in the synchronous operation mode.

Further, when the position signal pattern determining means determines that the energized state of the semiconductor switch element group by the commutation signal is the short-circuit mode, the output of the commutation signal is stopped. By restarting the motor with the generated torque larger than the previous time, it is possible to reduce the loss of synchronism and start the motor when the load torque of the motor is large.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a first embodiment of a brushless motor operation control device according to the present invention.

FIG. 2 is a timing chart of an operation mode of the embodiment.

FIG. 3 is a flowchart showing the operation of the embodiment.

FIG. 4 is a flowchart showing an operation of a brushless motor operation control device according to a second embodiment of the present invention;

FIG. 5 is a flowchart showing the operation of a brushless motor operation control device according to a third embodiment of the present invention;

FIG. 6 is a flowchart showing the operation of a fourth embodiment of the brushless motor operation control device according to the present invention;

FIG. 7 is an overall configuration diagram of a conventional brushless motor operation control device.

FIG. 8 is a timing chart of an operation mode of a conventional operation control device for a brushless motor.

FIG. 9 is a flowchart showing the operation of a conventional operation control device for a brushless motor.

[Explanation of symbols]

Reference Signs List 1 DC current 2 Semiconductor switching element group 3 Brushless motor 4 Armature winding 5 Magnet rotor 6 Rotor position detecting means 6X, 6Y, 6Z Rotor position detecting signal 9 Commutation signal generating means 9U +, 9V +, 9W +, 9U- , 9V-, 9W- Commutation signal 10 Position signal pattern determination means

Claims (4)

[Claims] A brushless motor having a multi-phase armature winding connected to a neutral ground and a magnet rotor; a DC power supply; and a semiconductor switching element for energizing and interrupting a current to the armature winding. A group, position detecting means for detecting a relative position of the magnet rotor with respect to the armature winding by a voltage signal induced in the armature winding by rotation of the magnet rotor, and the position detecting means A rotor position detection operation mode in which the brushless motor is driven by a commutation signal generated from the rotor position detection signal obtained by the conversion, and the commutation is forcibly performed until the rotor position detection signal is established. A synchronous operation mode for outputting a signal to generate a rotating magnetic field to drive the brushless motor. During the synchronous operation mode, a commutation signal is forcibly output, and the rotor position detection is performed. A commutation signal generating means for generating a commutation signal based on the output of the rotor position detecting means during the outgoing operation mode, and after outputting the final commutation signal pattern in the synchronous operation mode, A brushless motor having position signal pattern determining means for confirming a pattern of a rotor position detection signal and determining a specific commutation signal to be output based on the pattern of the position detection signal when shifting to the position detection operation mode. Operation control device. 2. The method according to claim 1, wherein the position signal pattern determining means outputs a commutation signal when the commutation signal determines that the energized state of the semiconductor switching element group is the short-circuit mode when shifting from the synchronous mode to the rotor position detection operation mode. 2. The operation control device for a brushless motor according to claim 1, wherein the operation is stopped, and the commutation signal generating means restarts after temporarily stopping. 3. The commutation signal generating means, when the commutation state of the semiconductor switching element group by the commutation signal is determined to be a short-circuit mode when the mode is shifted from the synchronous mode to the rotor position detection operation mode, 2. The brushless motor operation control device according to claim 1, wherein the output of the commutation signal is maintained as it is, and when the pattern of the position detection signal changes, the pattern of the rotor position detection signal is checked again. 4. A position signal pattern judging means, when shifting from a synchronous mode to a rotor position detecting operation mode, judging that an energized state of a semiconductor switching element group by a commutation signal is a short circuit mode, outputs a commutation signal output. 2. The brushless motor operation control device according to claim 1, wherein the operation is stopped, and the commutation signal generating means restarts after temporarily stopping the motor, increasing the generated torque from the previous time.