KR20060133301A - Bldc motor and driving circuit therein - Google Patents

Abstract

A BLDC(Brushless Direct Current) motor and a driving circuit thereof are provided to achieve high speed driving of a motor by supplying a driving current of each phase to an independent coil at every fixed electrode by winding two independent coils at each fixed electrode of a stator. A BLDC(Brushless Direct Current) motor has a stator(120) of a fixed electrode(120_3) wound with a coil and a rotor(140) rotated by a current supplied to the coil. Two coils wound along an opposite direction respectively are formed in each fixed electrode of the stator. One of two coils is wound along a positive direction, and another coil is wound along a reverse direction.

Description

BLDC motor and its driving circuit {BLDC MOTOR AND DRIVING CIRCUIT THEREIN}

1 is a circuit block diagram showing a BLDC motor and a driving circuit thereof according to the prior art;

2 is a perspective view showing a stator structure in which a coil is wound in a conventional BLDC motor;

3A and 3B are a plan view and a perspective view showing a stator structure in which a coil is wound in a BLDC motor according to an embodiment of the present invention;

4 is a block diagram schematically showing a driving circuit of a BLDC motor according to the present invention;

5 is a circuit block diagram illustrating a BLDC motor and a driving circuit thereof according to an embodiment of the present invention.

<Description of the code | symbol about the principal part of drawing>

100: switching IC

110: a plurality of switching unit

120: multiple forward and reverse coils

130: power supply

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless direct current (BLDC) motor and its driving circuit, and more particularly to a BLDC motor and its driving circuit capable of achieving high speed driving of the motor.

In general, since the BLDC motor eliminates mechanical contact parts such as commutators and brushes in the DC motor, electrical and mechanical noise is not generated, and its life is long.

Such a BLDC motor has a rotor having a plurality of permanent magnets for forming a magnetic field, and a stator with a coil wound to generate torque for rotating the rotor by interaction with the magnetic field by the permanent magnet of the rotor. Contains a stator. The stator uses an armature that applies a current to the coil to form a rotating magnetic field, and the rotor uses a permanent magnet formed by repeating the N pole and the S pole. At this time, the rotor is located outside of the stator, the outer rotor (outer rotor) structure, and the inside of the stator is called the inner rotor (inner rotor) structure.

The BLDC motor has a driving circuit for supplying current to the coil so that the magnetic pole of the magnetic field generated in the coil of the stator is always 90 ° with the magnetic pole installed in the rotor.

Fig. 1 is a circuit block diagram showing a BLDC motor and a driving circuit thereof according to the prior art, taking a three phase motor as an example. Referring to FIG. 1, a BLDC motor according to the related art includes a stator 30, a rotation shaft 40, and a rotor 50. Here, the stator 30 may include a yoke 34 formed in a cylindrical shape having an upper and lower sides open, and two or more fixed electrodes protruding at regular intervals in a circumferential direction toward the rotor 50 from the inner wall of the yoke 34 ( 36). The rotating shaft 40 transmits the driving force of the motor to the center of the rotor 50 in the structure of the internal rotor to rotate the rotor 50. The rotor 50 includes one or more pairs of permanent magnets composed of pairs in which the N pole and the S pole face each other.

The driving circuit of the BLDC motor includes a switching IC 10 and a switching unit 20 including a full bridge circuit for supplying current to the coil and determining the direction of the current. For example, the switching unit 20 receives a signal from the switching IC 10 and supplies a current in a forward or reverse direction to the coil. At this time, if the coil 32 is composed of one coil is wound in a fixed direction of the fixed electrode of the stator 30, and alternately to the N pole S poles respectively in the direction of the current.

In the BLDC motor according to the related art, the switching unit 20 is driven by a drive signal of the switching IC 10, and the current in the forward or reverse direction to each coil 32 wound around the fixed electrode of the stator 30 in a predetermined direction. Rotating the rotor 50 in accordance with the magnetic field interaction between the magnetic pole of the magnetic field generated in each coil 32 and the magnets of the N and S poles of the rotor 50.

2 is a perspective view showing a stator structure in which a coil is wound in a conventional BLDC motor. Referring to FIG. 2, in the stator 30 of the conventional BLDC motor, coils 32 are wound around each of the fixed electrodes 36 protruding from the inner wall of the yoke 34 formed in a cylindrical shape in which the upper and lower sides are opened. Since the coils 32 are wound in opposite directions to each other, the fixed electrodes 36 positioned in the magnet are rotated by excitation with + or − electricity according to the magnetic pole determined by the sensor.

However, in the conventional BLDC motor, since the coils 32 are wound in series on the fixed electrodes 36 in the order of the fixed electrodes 36 of the stator 30 as shown in FIG. During alternating with electricity, back electromotive force is generated and a current collision is generated between the residual current of the pre-excited electrode and the post-excitation which is excited with the opposite polarity. Accordingly, the conventional BLDC motor has a problem that it is difficult to drive high power and high speed through the driving circuit because the current and the speed flowing in the coil are limited due to the counter electromotive force and the current collision that increases as the speed increases.

An object of the present invention is to solve the conventional problems as described above, by winding two independent coils for each fixed electrode of the stator to supply the drive current of each phase to the independent coil for each fixed electrode to achieve high speed driving of the motor. To provide a BLDC motor that can.

Another object of the present invention is to provide a driving circuit of a BLDC motor for supplying driving current of each phase to two coils wound around each fixed electrode of the stator.

In order to achieve the above object, the present invention, in the BLDC motor having a stator of the fixed electrode wound the coil, and a rotor rotated by the current supplied to the coil, each of the fixed electrodes of the stator are wound in opposite directions to each other The two coils are formed.

In order to achieve the above object, the present invention provides a driving circuit of a BLDC motor having a stator formed with two coils wound in opposite directions on each fixed electrode, and a rotor rotated by a current supplied to the coil. And a switching IC for generating a switching signal, and a plurality of switching sections for supplying a driving current to any one of two coils switched by signals of the switching IC and wound around each fixed electrode of the stator.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

3A and 3B are plan and perspective views illustrating a stator structure in which a coil is wound in a BLDC motor according to an embodiment of the present invention.

3A and 3B, a BLDC motor having a three-phase structure according to an embodiment of the present invention includes a stator 120 wound around two fixed coils 120, a rotating shaft 130, and a rotation for each fixed electrode 120_3. Electron 140.

Here, the stator 120 includes a yoke to serve as a passage of the electromagnetic field and a plurality of fixed electrodes 120_3 disposed to have a predetermined direction and a gap with respect to the yoke so as to protrude so as to wind the coil in contact with the yoke.

Each of the fixed electrodes 120_3 of the stator 120 according to the present invention has two coils 120a and 120b (120c and 120d) 120e and 120f (120g and 120h) 120i and 120j and 120k and 120l. It is wound in opposite directions. For example, coils of 120a, 120c, 120e, 120h, 120j and 120l are wound in the forward direction, and coils of 120b, 120d, 120f, 120g, 120i and 120k are wound in the reverse direction. On the contrary, coils of 120a, 120c, 120e, 120h, 120j and 120l are wound in the reverse direction, and coils of 120b, 120d, 120f, 120g, 120i and 120k are wound in the forward direction.

Drive currents in the two coils 120a and 120b (120c and 120d) 120e and 120f (120g and 120h) 120i and 120j (120k and 120l) wound on the respective fixed electrodes 120_3 of the stator 120. Are alternately supplied, the rotor 140 according to magnetic field interaction between the magnetic pole of the magnetic field generated by the current flowing through each coil of each fixed electrode 120_3 and the magnets of the N and S poles of the rotor 140. Is rotated. At this time, the driving current is supplied to the coils wound on the fixed electrode 120_3 positioned in the directions symmetrical with respect to the rotation center line to have opposite polarities.

Here, the rotating shaft 130 transmits the kinetic energy of the motor obtained by the rotor rotational force in the center of the rotor 140 to the driven body or the load device. The rotor 140 supports cores and cores that are cut and stacked in a predetermined shape to prevent the permanent magnets from being separated from the centrifugal force and one or more pairs of permanent magnets composed of a pair of N and S poles facing each other. Dovetail and permanent magnets are installed so as not to be separated up and down.

In the BLDC motor according to the present invention, two coils 120a and 120b wound around the fixed electrodes 120_3 in the A, B, C, D, E, and F phases in the fixed electrodes 120_3 of the stator 120 ( 120c, 120d) 120e, 120f (120g, 120h) 120i, 120j (120k, 120l) are alternately supplied to supply driving currents of different polarities, so that the fixed electrodes are driven by currents flowing in two independent coils. Since the electromagnetic field of the N pole or the S pole is generated at 120_3, current collision and counter electromotive force due to the residual current are not generated.

4 is a block diagram schematically showing a driving circuit of a BLDC motor according to the present invention, taking a BLDC motor of a three-phase structure as an example. Referring to FIG. 4, the driving circuit for driving the BLDC motor according to the present invention includes a switching IC 100 generating a PWM signal and a driving signal for switching the switching unit 110, and a signal of the switching IC 100. And a plurality of switching units 110 for supplying driving currents to the forward and reverse coils wound by the fixed electrodes of the stator 120, respectively. Here, reference numeral 150 denotes a power supply unit for supplying power or driving power to the plurality of switching units 110.

The plurality of switching units 110 may include, for example, a first switching unit 110a and a second switching unit for supplying a driving current to two coils wound on fixed electrodes of six stators in a three-phase BLDC motor. 110b), the third switching unit 110c, the fourth switching unit 110d, the fifth switching unit 110e, and the sixth switching unit 110f.

Here, the first switching unit 110a is connected to the first forward coil 120a wound around the first fixed electrode and the fourth reverse coil 120g wound around the fourth fixed electrode positioned opposite to the first fixed electrode. Each supplies a drive current. The second switching unit 110b is driven by the first reverse coil 120b wound on the first fixed electrode and the fourth forward coil 120h wound on the fourth fixed electrode positioned opposite to the first fixed electrode, respectively. Supply the current. The third switching unit 110c drives the second forward coil 120c wound around the second fixed electrode and the fifth reverse coil 120i wound around the fifth fixed electrode positioned opposite to the second fixed electrode, respectively. Supply the current. The fourth switching unit 110d is driven by the second reverse coil 120d wound on the second fixed electrode and the fifth forward coil 120j wound on the fifth fixed electrode positioned opposite to the second fixed electrode, respectively. Supply the current. The fifth switching unit 110e supplies driving currents to the third forward coil 120e wound on the third fixed electrode and the sixth reverse coil 120k wound on the sixth fixed electrode, respectively. Finally, the sixth switching unit 110f supplies driving currents to the third reverse coil 120f wound on the third fixed electrode and the sixth forward coil 120l wound on the sixth fixed electrode, respectively.

The BLDC motor driving circuit according to the present invention switches the plurality of switching units 110 according to the signal of the switching IC 100, and the positive direction wound on each fixed electrode of the stator 120 by each switched switching unit 110. Supply the drive current to the coil or reverse coil respectively.

5 is a circuit block diagram illustrating a BLDC motor and a driving circuit thereof according to an embodiment of the present invention.

Referring to FIG. 5, in an example of a BLDC motor driving circuit according to an exemplary embodiment of the present invention, the first to sixth switching units 110 (110a, 110b,) switched by a signal of the switching IC 100. Each of 110c, 110d, 110e, and 110f has an emitter of a transistor driven by transistors (for example, a totem pole circuit) connected to a power supply terminal and a ground terminal of the power supply, respectively, with one end connected to the driving power source (VDC). The forward coils 120a, 120c, 120e, 120h, 120j, and 120l are connected to the reverse coils 120b, 120d, 120f, 120g, 120i, and 120k, and the collector is connected to ground. Here, as the transistor of the switching unit 110, an IGBT, a MOSFET, a FET, a bipolar transistor, or the like is widely used.

The BLDC motor and its driving circuit according to an embodiment of the present invention configured as described above operate as follows.

As the signals of the switching IC 100 are input to the plurality of switching units 110, the driving transistors of the first switching unit 110a are operated to be wound around the first fixed electrode on A +, and one end thereof is supplied to the power source VDC. The fourth forward electrode 120a connected to the first forward coil 120a and D + is wound on the fourth fixed electrode so that the driving current flows to the fourth reverse coil 120g connected to the power source VDC.

The driving signal outputted through the transistor of the second switching unit 110b is wound on the first fixed electrode to the A-phase, so that one end thereof is connected to the first reverse coil 120b and the D-phase. The second winding is wound around the fixed electrode so that the driving current flows through the fourth forward coil 120h connected to the other end of the power source VDC.

The driving signal output through the transistor of the third switching unit 110c is wound on the second fixed electrode to the B + phase, and the second forward coil 120c connected to the power source VDC at one end thereof, and the fifth fixed to the E + phase. The driving current is flowed to the fifth reverse coil 120i which is wound around the electrode and connected to the power source VDC.

The driving signal output through the transistor of the fourth switching unit 110d is wound on the second fixed electrode to the B-phase and the second reverse coil 120d connected to the power supply VDC at one end thereof, and the fifth to the E-phase. Winding around the fixed electrode allows the other end to flow a driving current to each of the fifth forward coil (120j) connected to the power source (VDC).

The driving signal output through the transistor of the fifth switching unit 110e is wound on the third fixed electrode to the C + phase, and one end thereof is fixed to the third forward coil 120e connected to the power source VDC, and the sixth fixed to the F + phase. The driving current flows to the sixth reverse coil 120k connected to the power source VDC by winding the electrode.

The driving signal output through the transistor of the sixth switching unit 110f is wound on the third fixed electrode to the C-phase and the third reverse coil 120f connected to the power supply VDC at one end thereof, and the six to the F-phase. It is wound around the first fixed electrode so that the other end of the driving current flows through each of the sixth forward coil 120l connected to the power source VDC.

As described above, the BLDC motor driving circuit according to the present invention switches the plurality of switching units 110 according to the signal of the switching IC 100 and drives each of the forward coils and the reverse coils wound around the fixed electrodes of the stator 120. By supplying current, the rotor 140 is rotated according to magnetic field interaction between magnetic poles of the magnetic field generated in each coil and magnets of the N and S poles of the rotor 140.

As described above, the BLDC motor according to the present invention is a forward or reverse coil for each fixed electrode through the drive circuit by winding two coils with different winding directions to supply + and-current to each fixed electrode of the stator. The drive current can be supplied by selecting.

Accordingly, in the present invention, since the + and-currents are not alternated in the coils wound on the respective fixed electrodes of the stator, only the current flows in the same direction, so that no counter electromotive force is generated and a collision due to the alternating current does not occur. Stable supply improves motor efficiency and enables high-speed operation of the motor because there is no damage to the control device due to back EMF at high speed.

What has been described above is just one embodiment for implementing the BLDC motor and its driving circuit according to the present invention, and the present invention is not limited to the above-described embodiment, as claimed in the following claims. Without departing from the gist of the present invention, those skilled in the art to which the present invention pertains to the technical spirit of the present invention to the extent that various modifications can be made.

Claims (4)

In a BLDC motor having a stator of a fixed electrode wound with a coil and a rotor rotated by a current supplied to the coil, Each fixed electrode of the stator is formed with two coils wound in opposite directions, respectively BLDC motor, characterized in that. The method of claim 1, Two coils wound on each of the fixed electrodes, one of which is wound in the forward direction and the other is the BLDC motor, characterized in that the winding in the reverse direction. In a driving circuit of a BLDC motor having a stator having two coils wound in opposite directions to each fixed electrode, and a rotor rotated by a current supplied to the coil, A switching IC for generating a switching signal, A plurality of switching unit for supplying a drive current to any one of the two coils are wound by the signal of the switching IC and wound on each fixed electrode of the stator Drive circuit of the BLDC motor comprising a. The method of claim 3, wherein And the switching unit includes two or more transistors each connected to the two coils, respectively.

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