JP2000278988A - Device for driving brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately start a motor by composing the combination of stator coil winding to be energized first when the motor is started so that the combination can be changed each time when the motor is started. SOLUTION: The device gives a drive signal to a drive circuit so that stator coil winding to be energized is successively switched based on the position detection signal of a rotor obtained by detecting the change in an induced voltage from each motor terminal by a position detection circuit using a microprocessor. Then, when a brushless motor is to be started, the combination of the stator coil winding is stored in the microprocessor in advance as a conduction pattern for starting conduction from a conduction pattern 1, the conduction pattern is switched successively, and a rotor in halt state is rotated. In this case, the conduction pattern to be energized first is changed each time when the motor is started from the conduction pattern 1 in the first start and from a conduction pattern 2 from the next start, thus preventing the same mistake from being repeated and appropriately starting the motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a change in an induced voltage generated in a stator winding which has a plurality of permanent magnets and is not energized by rotation of a rotor, and energizes based on this detection signal. The present invention relates to a brushless motor driving device in which slave windings are sequentially switched.

[0002]

2. Description of the Related Art As a conventional technology of a motor driving device,
There is one described in JP-A-7-147795. The starting method of the brushless motor described in this publication and the like is started by synchronous operation in which the energization to the stator winding is sequentially switched, and the energization cycle is gradually increased to increase the rotor speed to a predetermined speed. It was to switch to position detection error due to induced voltage.

[0003]

In the method of starting a brushless motor disclosed in the above-mentioned publication, the rotor position is unknown at the time of starting and is not always the same, so that the current is supplied from a predetermined combination of stator windings. When the motor starts, the combination of the stator windings to be energized is not always appropriate, and depending on the state of the rotor reversing and the load torque, synchronous operation cannot be performed, and the motor starts. It may not be possible. Further, when starting is failed and restarting is performed, energization is started from the same combination of stator windings as in the case where starting has failed, and thus there is a possibility that the same starting failure may be repeated.

An object of the present invention is to provide a brushless motor starting device in which the starting of the motor is improved.

[0005]

In order to solve the above-mentioned problems, a rotor having a plurality of permanent magnets and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized are provided. Having a rotating magnetic field by energizing some stator windings of the plurality of stator windings, and causing a change in an induced voltage caused by rotation of the rotor to a non-energized stator winding. In a brushless motor drive device that detects and sequentially switches the stator windings to be energized based on this detection signal, the combination of stator windings to be energized first when the motor is started is changed every time the motor is started. It is configured as follows.

[0006] Further, it has a rotor having a plurality of permanent magnets and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. The stator which energizes some of the stator windings to obtain a rotating magnetic field, detects changes in the induced voltage caused by rotation of the rotor in the non-energized stator windings, and energizes based on this detection signal. In a brushless motor drive device in which the windings are sequentially switched, when the motor cannot be started normally and restarted, the identifier windings other than the combination of the stator windings that could not be started normally are not used. The first energization is started from the combination.

Further, the rotor has a rotor having a plurality of permanent magnets and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. Some of the stator windings are energized to obtain a rotating magnetic field, and the non-energized stator windings are detected for a change in the induced voltage caused by rotation of the rotor, and energized based on this detection signal. In the brushless motor driving device configured to sequentially switch the stator windings, when the motor cannot be started normally and restarted, the combination of the stator windings that can be normally started is started first. Is configured to start energization.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment (corresponding to claim 1) of the present invention will be described with reference to the drawings.

FIG. 1 shows a control block diagram of an embodiment of the present invention. The AC power supply 1 is connected to a brushless motor 5 via a semiconductor switching element 4 rectified by a rectifier circuit 2 and connected in a three-phase bridge.

The microprocessor 7 includes a position detecting circuit 6
Then, based on a rotor position detection signal obtained by detecting a change in induced voltage from each motor terminal, a drive signal is supplied to a drive circuit so as to sequentially switch the stator winding to be energized.

When starting a brushless motor, FIG.
As shown in (1), the combination of the identifier windings is stored in the microprocessor in advance as the energization pattern, energization is started from energization pattern 1, and the energization pattern is sequentially switched to rotate the stopped rotor.

Here, the energization pattern to be energized first at the start is not the same energization pattern, but is, for example, from energization pattern 1 at the first start and energization pattern 2 at the next start.
Each time the engine is started, the energization pattern to be energized first is changed.

The pattern to be energized first may be selected in order from pattern 1 to pattern 6, or a method of selecting a pattern as shown in FIG. 3 or a method of selecting randomly. When energization starts from energization pattern 1 and fails to start, and restarts, the same energization pattern l
Instead, the energization is started from another energization pattern (for example, energization pattern 2), thereby preventing the same start failure from being repeated.

Next, a second embodiment (corresponding to claims 2 and 3) will be described. Similar to the first embodiment, the energization pattern that is initially energized when the motor is started is changed every time the motor is started. Here, when the start fails, the first energization pattern at the time of the start failure is stored in a memory in the microprocessor so that the start from the same energization pattern as at the time of the failure is prevented. The case where the selection of the energization pattern to be energized first is performed in order from the energization pattern 1 to the energization pattern 6 will be described as an example. When starting for the first time, energization is started from energization pattern 1. When the engine is started next time, the energization is started from the energization pattern 2, and thereafter, every time the engine is started in the same manner, the patterns 1 to 6 are applied.
Select up to in order. Here, when the energization is started from the energization pattern 1 and the start fails, the pattern 2 to the pattern 6 are sequentially selected so as not to start the energization from the energization pattern 1. In other words, the starting in which the energization is started from the same energization pattern as in the case where the starting has failed is not performed, and the same starting failure is prevented from being repeated.
Also, if the number of start failures is large, the number of failures and the energization start pattern at that time are stored in the memory in the microprocessor, and energization is started from the energization pattern with a small number of start failures, and the probability of starting failure is determined. It can be lowered. As a result, the starting can be made good.

[0015]

As described above, according to the brushless motor driving apparatus of the present invention, when the energization is started from a certain energization pattern and the start fails, and when the motor is restarted, it is not based on the same energization pattern but a different one. The energization is started from the energization pattern described above, and the same start failure can be prevented from being repeated.

According to the second aspect of the present invention, it is possible to prevent the start of energization starting from the same energization pattern as in the case where the start has failed, thereby preventing the same start failure from being repeated.

According to the third aspect of the present invention, if the number of failures in starting is large, the number of failures and the energization start pattern at that time are stored in a memory in the microprocessor, and the energization pattern with a small number of failures in starting is stored. It is possible to start energization and reduce the probability of starting failure. As a result, the starting can be made good.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram showing an energization pattern of a stator winding to be energized.

FIG. 3 is an explanatory diagram showing a relationship between the number of times of starting and an example of an energization pattern for energizing first.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 AC power supply 2 Rectifier circuit 3 Smoothing capacitor 4 Semiconductor switching element 5 Three-phase DC brushless motor 6 Position detection circuit 7 Microprocessor 8 Drive circuit

(72) Inventor Hideaki Kato 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Tetsuo Nomoto 2-5-5-1 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Shin Sekino F-term (reference) 5H560 BB04 BB12 DA13 DA19 DB20 GG04 HA09 SS01 SS07 TT15 UA10 2-5-5 Keihanhondori, Moriguchi-shi, Osaka

Claims (3)

[Claims] 1. A rotor having a plurality of permanent magnets and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. The stator which energizes some of the stator windings to obtain a rotating magnetic field, detects changes in the induced voltage caused by rotation of the rotor in the non-energized stator windings, and energizes based on this detection signal. A brushless motor driving device in which windings are sequentially switched, wherein a combination of stator windings to be energized first when the motor is started is changed every time the motor is started. 2. A rotor having a plurality of permanent magnets and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. The stator which energizes some of the stator windings to obtain a rotating magnetic field, detects changes in the induced voltage caused by rotation of the rotor in the non-energized stator windings, and energizes based on this detection signal. In a brushless motor drive device in which the windings are sequentially switched, when the motor cannot be started normally and restarted, the identifier windings other than the combination of the stator windings that could not be started normally are not used. A drive device for a brushless motor, wherein the first energization is started from a combination. 3. A rotor having a plurality of permanent magnets and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. A current is applied to some of the stator windings to obtain a rotating magnetic field, and a change in the induced voltage caused by the rotation of the rotor is detected in the non-energized stator windings. In the brushless motor drive device configured to sequentially switch the child windings, when the motor cannot be started normally and restarted, the combination of the stator windings that can be normally started many times is used first. A drive device for a brushless motor, which starts energization.