JPH03215184A - Driving system of brushless motor - Google Patents

Abstract

PURPOSE:To widen the working range of a brushless motor by switching the electrification angles and phases of respective driving phases based on 5-phase magnet position detecting signal, to perform 5-phase driving, and by switching the static characteristic of the motor. CONSTITUTION:When a brushless motor composed of 5 coils and 6 poles is 5-phase-driven, then a magnet 1 is forned in the shape of a disk, and on its plate surface, the 6 poles of the poles-N and the poles-S are alternately magnetized radially at equal pitches. Besides, the magnet 1 and coils LA-LE are confronted with each other with a uniform gap between them and are arranged. When the electrification signals of respective driving phases are created with the use of the 2 or more of the detecting signals of the magnet position detecting means of the 5-phase brushless-motor, then the input of the detecting signals to be provided to a means for creating the electrification signals of the respective driving phases is switched, and the electrification angles and phases of the electrification signals are contrived to be changed. As a result, the static characteristic of the motor can be changed according to a using situation.

Description

[Detailed description of the invention] The present invention will be explained in the following order.

A. Industrial field of application B. Outline of the invention C. Prior art D. Problem to be solved by the invention E. Means for solving the problem F. ActionG. Example Gr. Configuration and operation of the first embodiment G, . Description of second embodiment G3. Description of third embodiment and application example H. Effect of invention A. INDUSTRIAL APPLICATION FIELD The present invention relates to a drive system for expanding the operating range of a brushless motor.

B. Summary of the Invention The present invention provides a brushless motor drive system that performs multi-phase drive by switching the energization angle of each drive phase based on multi-phase magnet position detection signals, and by switching the static characteristics of the motor. This is designed to expand the range of motion of the branoless motor.

C. A capstan motor in a conventional VTR (video tape recorder) not only rotates the capstan to control tape travel, but also drives a reel. Therefore, fast forwarding and rewinding require high speed rotation, slow playback requires high torque to perform step forwarding, and during normal playback, the load on the motor is small. Thus, the capstan motor of a VTR is required to have a wide operating range. In order to obtain such a wide operating range, it is sufficient to perform power control, but such power control is performed using a motor drive IC (
Since it is difficult to place a burden on the integrated circuit (integrated circuit), conventional sets have a method of reducing the burden (heat generation) by switching the power supply voltage applied to the motor in two stages, and controlling all of this power using Uiro's power transistors. , methods such as driving voltage (Vs) control were adopted in which heat was radiated in the set chassis.

D. Problems to be Solved by the Invention However, the conventional method for driving a capstan motor described above increases the number of parts, which increases cost and hinders miniaturization of the set.

The present invention was created in order to solve the above problems, and allows the static characteristics of a branless motor to be controlled using a small signal system, making it possible to use an IC, making it possible to miniaturize the set and reduce costs. The purpose of the present invention is to provide a drive system for a branless motor.

E Means for Solving the Problems The configuration of the drive system of the brushless motor of the present invention to achieve the above object includes: a magnet position detection means of a multi-phase brushless motor; and detection of two or more of the above magnet position detection means. means for inputting a signal to create an energization signal for each drive phase, and switching the input of the two or more detection signals to the means for creating an energization signal for each drive phase, It is characterized by changing the static characteristics of

F. Effect The present invention provides an input signal to the means for creating the energization signal for each drive phase when creating the energization signal for each drive phase using two or more detection signals of the magnet position detection means of a multi-phase brushless motor. By switching the detection signal and changing the energization angle of the energization signal, the static characteristics of the motor can be changed depending on the usage situation, thereby widening the operating range of the branless motor.

G. Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

G1. Structure and operation of the first embodiment FIGS. 1(a) and (b). (c) shows a block diagram of the magnetic circuit system of a flat brushless motor showing the first embodiment of the present invention, (a) shows the magnetized state of the magnet forming the rotor, and (b) shows the magnetized state of the magnet forming the rotor. The coil arrangement on the stator side is shown (
c) shows a diagram of the positional relationship between the magnet and the coil viewed from the lateral direction. In this embodiment, a flat brushless motor having a five-coil, six-pole configuration is driven in five phases. The magnet I is formed in the shape of a disk, and has six north poles and six south poles magnetized radially at equal pitch angles on the disk surface. On the other hand, on the stator side, the 5
coil LA. LB. The LC and LoLE are arranged, for example, on the substrate 1 in an annular shape at equal pitch angles. Magnet I and coil LA formed and arranged in this way
E and E are arranged opposite to each other with a uniform gap as shown in (c).

FIG. 2 is a drive circuit diagram of the brushless motor configured as described above. The drive circuit of this embodiment has each phase drive circuit section 3a. 3b3c. 3d. 3e
(hereinafter referred to as each phase drive circuit section 3 in a representative case), and Hall elements HA, He, Hc. Ho,
He and signals +A, +B, 10. Amplifier circuits 4a, 4b, 4 that create +D, +E and their inverted signals -A, -B, -C, -D, -E and manually input them to each phase drive circuit section 3
c, 4d, and 4e. Each phase drive circuit section 3a~
Since each of the amplifier circuits 3e and the amplifier circuits 4a to 4e is configured in the same manner for each phase, the circuit configuration will be described below using the phase A drive circuit 3a and the amplifier circuit 4a as examples for driving the coil LA.

The amplifier circuit 4a includes a differential amplifier consisting of an operational amplifier 4l and an inverting amplifier consisting of an operational amplifier 42, which are connected in series. In the operational amplifier 4l, the detection output (Hall voltage) of the Hall element HA is connected to an inverting input terminal (-) and a non-inverting input terminal (+) through resistors R, , R2, respectively. The output of the operational amplifier 4l becomes the aforementioned signal 1A, and the output -A is connected to the inverting input terminal (1) through the resistor R3.
When connected to , operational amplifier 4 is connected through resistor R4.
It is connected to the inverting input terminal (-) of No.2. operational amplifier 42
The output becomes the aforementioned signal 10A, which is input to each phase drive circuit section 3, and is also connected to the inverting input terminal (-) of the operational amplifier 42 through the resistor R. The non-inverting input terminal (+) of the operational amplifier 41 is connected to the operational amplifier 42 through the resistor R6.
The non-inverting input terminal (+) of is connected to an operational amplifier 43 common to each amplifier circuit 4a to 4e and a resistor R through a resistor R.
, R a is connected to the output of a zero balance circuit.

The circuit of the operational amplifier 43 consists of two resistors R s and R
9 is connected in series between the circuit power supply Vcc and ground,
Both resistances R. ,R. The connection point of the operational amplifier 43 is connected to the non-inverting input terminal (+) of the operational amplifier 43, and the output of the operational amplifier 43 is connected to its inverting input terminal (-).

The Hall element HA includes other Hall elements H e - H
A constant current for magnet position detection is passed in parallel with E through the output of an operational amplifier 44. The circuit of the operational amplifier 44 includes a resistor R1. and variable resistor VR, or circuit power supply V. C and ground, and a Zener diode ZD. is connected, variable resistor VR,
The variable terminal of the operational amplifier 44 is connected to the non-inverting input terminal (+), and the output of the operational amplifier 44 is connected to the inverting input terminal (+) of the operational amplifier 44.
−). Similarly, the amplifier circuit 4b inputs the detection output of the Hall element HB and receives the signal 1B. -B, and the amplifier circuit 4c inputs the detection output of the Hall element He to generate a signal 1C. -C, the amplifier circuit 4d inputs the detection output of the Hall element HD and generates signals 1D and -D, and the amplifier circuit 4e inputs the detection output of the Hall element HE and generates signals 1E and -E. Create.

Next, the configuration of each phase drive circuit section 3 will be described. Each phase drive circuit section 3λ receives signals -l-A, - from among the signals indicating the interlinkage magnetic flux of each phase and their inverted signals from the respective amplifier circuits 41 to 4e.
A, +B, 4-C. -C, +D, -D, +E manually,
These signals are sent to switches SWI, SW, . SW3, SW
．． Operational amplifier 31 as signal comparison means
, 32.33.34 and from their outputs exclusive OR (CEXOR) circuit 35 and NOR
By circuit? Get the electric signal and turn on the circuit power supply VCC side/
Transistor Q. turned off. ,Q,. Transistors Q4, Q5, which turn on/off the pair of Q3 and the ground side. A switching circuit is formed with the set Qa, and the coil LA is energized in both directions at a energization angle determined by the settings of switches SWl-SW. An analog switch can be used as each switch SW, to SWs. The signal 10A is connected to the non-inverting input terminal (+) of the operational amplifier 3l, the switching terminal U side of one of the switches SW and SW4, and the inverting input terminal (-) of the operational amplifier 34. The signal 18 is connected to the inverting input terminal (-) of the operational amplifier 3l and the non-inverting input terminal (+) of the operational amplifier 34. Signal 10B is switch S
The signal 10C is connected to one switching terminal V side of the switch W■, and the signal 10C is similarly connected to the other switching terminal U side of the switch S W +. Hereinafter, the signal 1C is connected to the switching terminal V side of the switch SW a, the signal 1D is connected to the switching terminal U side of the switch SW t, the signal 1D is connected to the switching terminal V side of the switch SW4, and the signal ±E is connected to the switch Connect to the switching terminal V side of SW, respectively. In the OBE 32, the common terminal of the switch SW1 is connected to the inverting input terminal (-), the common terminal of the switch SW3 is connected to the non-inverting input terminal (+), and the output X is connected to one side of the exclusive OR circuit 35. Connect to input. In the operational amplifier 33, the common side of the switch SW is connected to the inverting input terminal (-), the common side of the switch SW4 is connected to the non-inverting input terminal (+), and the output Y is connected to the exclusive OR circuit 35.
Connect to the other input of The output of exclusive OR circuit 35 is connected to one input of NOR circuits 36 and 37. The output of the operational amplifier 3l is connected to the other input of the NOR circuit 36, and the output of the operational amplifier 34 is connected to the other input of the NOR circuit 37.

The configuration of the switching circuit that energizes the coil LA will be described below. Circuit power supply■. Set of np to turn on/off C side
In the n-type transistor Q1, its base is connected to the resistor R
It is connected to the output of the NOR circuit 36 through Il, and to the ground GND through a resistor R+t, with its emitter connected to the ground GND and its collector connected through resistors R and 3 to the base of a pnp transistor Q. In this transistor Q, the base is also connected to a resistor R. 4 through the circuit power supply V. The emitter is directly connected to the circuit power supply Vcc, and the collector is directly connected to the base of the npn transistor Q3. This transistor Q
3, the collector is connected to the circuit power supply V. Connect it to C, and connect the emitter to coil LA. Next, in the npn type transistor Q4 of the set that turns on/off the ground side,
Its base is connected to the output of the NOR circuit 37 through a resistor R15, and to the ground G through resistors R and 6.
ND, its emitter is connected to ground GND, and its collector is connected to the base of a pnp transistor Q5 through resistors R and 7, respectively. In this transistor Q5, the base is also connected to the circuit power supply V(
(The emitter is directly connected to the circuit power supply ■cc, and the collector is directly connected to the base of an npn transistor Q6. In this transistor Q8, the emitter is connected to the ground GND, and the collector is connected to the coil LA.Transistor Q ..Q is composed of power transistors.The other phase drive circuit sections 3b, 3c, 3d, and 3e are constructed in the same manner as above, but the input signals have different symbols. A→B-40-4D→E
→A→... and so on, as it changes sequentially,
The output of each switching circuit is sequentially connected to five-phase star-connected coils LB, Lc. Connected to Lo and LE.

The operation and effect of the embodiment configured as above will be described.

Figure 3. Figure 4. Figure 5. 6, 7, and 8 are timing diagrams explaining the operation, and FIG. Fourth
figure. Figure 5 shows the case where the energization angle is switched by normal energization for the A phase, and Figures 6 and 7. FIG. 8 similarly shows the case where the phase is advanced and the conduction angle is switched in order to improve the current delay in an iron core type brushless motor for the A phase. A shown in each figure. B. C, D, and E are the five-phase magnet position detection signals by the Hall element),
It is detected as a near sine wave with a phase shift of 72 degrees, and is amplified to send a signal +A to each phase drive circuit 4a to 4e in FIG.
, +B, +C, +D, +E and their inverted signals -A, -
Input as B, -C, -D, -E. In each phase drive circuit section 4a to 4e, the switch sw. -sw. By setting as shown in the table below, the logic shown in each figure is realized, and the conduction angles of each coil A to Li are set to 144° (Fig. 3), 108° (Fig. 4), and 72° (Fig. 5). (Fig. 6), phase lead of 126° (Fig. 6). 90° of phase advance (Figure 7). Switch to phase lead 108° (Fig. 8).

The switch switching setting table, that is, first, the input of the comparator 32 is changed to the switch sw,
, sw3 to select from signals +A, +B, +C, and C to generate signal X, and similarly, the input of the comparator 33 is set by switches sw, sw. Signals +A, +D, -D, +E with settings of
Then, the exclusive OR circuit 35 selects each signal X. The exclusive OR of X and Y is input to the NOR circuit 36 and 37 as a signal that determines the OFF period of the output stage (switching circuit), and the A-phase position detection signal +A. -Create a bidirectional energization signal from A.

Since the output stage is a switching operation, the NOR circuit 36 creates an ON signal for the upper stage power transistor Q3 from the +A signal and the OFF period signal, and the NOR circuit 37 creates a -
An on signal for the lower stage power transistor Q6 is created from the A signal and the off period signal. The above switches sw, -sw
．． In Figure 3, X is Arc. Y is created by the logic logic of A>D, and the power transistor Qs. Q6 is controlled to be turned on alternately at a conduction angle of 144°.

Similarly, in Figure 4, X or C=L (low level),
It is created using the logic of D=L, and in Figure 5, X is A>B,
Y is the logic of AGE, and in FIG. 6, X is C=L. Y is ADD logic, and in Figure 7, X is A>B, Y is D=
With the logic of L, in FIG. 8, X is A>B. Y are respectively created using the ADD logic, and the power transistors Q. ．． Q. are turned on alternately.

FIG. 9 is a motor characteristic diagram of the above embodiment, and the solid line is the third
As shown in the drive example in the figure, torque T vs. rotational speed N and torque T when operated with 144° energization by switch setting.
The broken lines represent the characteristics of torque T vs. rotational speed N and torque T vs. current I when operated at 72° current conduction as shown in the driving example of FIG. As is clear from this figure, it can be seen that in this embodiment, the motor characteristics can be varied in various ways by changing the current conduction angle of the coil by setting the switch.

G. Explanation of the second embodiment Fig. lθ (a). (b). (c) shows a configuration diagram of a magnetic circuit system of a flat planless motor showing a second embodiment of the present invention, (a) shows a magnetized state of a magnet forming a rotor, and (b) indicates the coil arrangement on the stator side,
(c) shows a diagram of the positional relationship between the magnet and the coil viewed from the lateral direction. This embodiment is an example in which a flat planar smoke having a five-coil, eight-pole configuration in which a thinning space is provided in the coil arrangement is driven in five phases. In this embodiment, N poles and S poles are radially magnetized alternately at equal pitch angles on the end face of a disk-shaped magnet l, and a flat coil LA on the stator side is disposed opposite to the north pole and south pole. LB, L
When arranging C, LD, and LE on the board 2,
The two poles (N pole and S pole) of the magnet 1 are thinned out and arranged. In this embodiment, this thinning space 2a can be used as a mounting space for circuit components. Since the five coils 8 to LE face the 6 poles of the magnet l, they have the same phase relationship as in the first embodiment, and the second
Actual examples are also shown in Figs. 3 and 4 using the drive circuit shown in Fig. 2.
The energization angle switching drive shown in FIG. 5 can be performed.

Gs. Explanation of third embodiment and application example 1. 1 (a), (b), and (c) are configuration diagrams of the magnetic circuit system of an iron-core brushless motor showing a third embodiment of the present invention, in which (a) shows the attachment of the magnet on the rotor side. (b) shows the iron core structure on the stator side, (C
) shows a cross-sectional view of the arrangement relationship between the magnet and the iron core viewed from the side. The magnet 1 is formed in the shape of a cylindrical ring, and has 16 N and S poles magnetized at equal pitches in the circumferential direction. This magnet I is fixed to the circumferential surface of the iron core 6 on the inner circumferential side of the rotatable yoke 5 with a predetermined gap maintained therebetween. The iron core 6 is formed by overlapping disc-shaped laminated steel plates to have 20 slots, and a coil (not shown) is wound between the slots.

According to such a configuration, it is possible to obtain five-phase interlinkage magnetic flux changes with a group of four coils, and the drive circuit shown in FIG. Figure 7. As shown in FIG. 8, it is possible to perform switching drive of the conduction angle in which the current delay caused by the large inductive reactance component (L component) of the coil is improved. Since the iron-core brushless motor of this embodiment has a large number of drive phases, it has the advantage of reducing cogging torque.

For example, in a conventional 3-phase, 24-slot, 16-pole branless motor, 48 times per revolution (the least common multiple of 24 and 16)
To generate cogging, two rows of grooves are formed in the core between the slots facing the magnet to reduce the number of cogging to 1.
The number of cogging torques was increased to 72 per rotation to reduce the cogging torque, but according to this embodiment, the number of coggings was reduced to 80 per rotation.
(the least common multiple of 20 and 16), the cogging torque can be reduced without providing a groove in the iron core 6, and the torque risopul can be reduced.

In addition, in the third embodiment, various combinations such as 20 slots and 18 poles, 25 slots and 20 poles, etc. can be used. Similarly, the first. The second embodiment can also be configured by combining the number of magnetic poles and the number of coils of other magnets. Further, the number of drive phases is not limited to five, and other multiphase drives are also applicable. in this way,
The present invention can be applied in various ways in accordance with its gist and can take various embodiments.

H. Effects of the Invention As is clear from the above explanation, the brushless motor drive method of the present invention provides the following advantages.

(1) By using one brushless motor, the motor characteristics can be selected according to the usage situation, and the operating range of the motor can be expanded.

(2) The characteristics of the motor can be changed with good controllability using a small signal system, and the heat generation of the drive circuit during low-speed rotation is reduced, which is advantageous for IC implementation.

(3) There is no need to switch the power supply system, the number of parts required for switching characteristics is reduced, and the set can be made smaller and costs reduced.

[Brief explanation of drawings]

1(a), (b), and (c) are block diagrams of the magnetic circuit system of a planless motor showing the first embodiment of the present invention, FIG. 2 is a drive circuit diagram of the planless motor, and FIG. 3, 4, 5, 6, 7, and 8 are timing diagrams for explaining the operation, FIG. 9 is a motor characteristic diagram of the above embodiment, and FIG. 10 (
a), (b), and (c) are block diagrams of a magnetic circuit system of a brushless motor according to a second embodiment of the present invention, and FIG. 11(a). (
b) and (C) are configuration diagrams of a magnetic circuit system of a brushless motor according to a third embodiment of the present invention. 1-・Magnet, 3a, 3b, 3c, 3d, 3e
- Amplifier circuit, 4a, 4b, 4c, 4d4 e - Each phase drive circuit section, LA, LB. LC, Lo, LE
- Coil, HA. HB, HC, HD, Ht-Hall element. ((1) (b) (C) First row of 4 rows of rows of dates 1.Flashless t-actor Fig. 11 Torque T.Flashless t-y stop. Document (i) January 7, 1991 Patent Application No. 7977 of 1990 2 Name of the invention Drive system of brushless motor 3. Relationship with the person making the amendment Case Applicant (2 1 8) Sony Corporation 4 . Agent Address: 1-29 Akashi-cho, Chuo-ku, Tokyo 104 Kisaikai Building 5. Subject of amendment 6. Contents of amendment (1) The scope of claims in the specification will be corrected as shown in the attached sheet. (2) Specification (3) The phrase “polyphase” on page 2, line 13 of the specification is corrected to “5-phase.” (4) Correct "polyphase" on page 4, line 13 of the specification to "5-phase." (5) Correct "5-phase" on page 5, line 4 of the specification. "Polymorphic" is replaced with "
5-phase,” he corrected. (6) The phrase "conducting angle" on page 5, line 8 of the specification is corrected to "conducting angle and phase." (7) In the specification, on page 20, line 12, the phrase ``Small signal system is used to control motor characteristics with good controllability'' is corrected to ``Small signal system is used to control motor characteristics.'' (Attachment) Claims (1) A five-phase brushless motor magnet position detection means, and a means for inputting a detection signal of the magneto position detection means to create an energization signal for each drive phase, A brushless motor drive method characterized in that the static characteristics of the brushless motor are changed by switching the energization angle and phase of the energization signal.

Claims (1)

[Claims] (1) Comprising a magnet position detection means for a multi-phase brushless motor, and a means for inputting two or more detection signals of the magnet position detection means to create an energization signal for each drive phase, A method for driving a brushless motor, characterized in that static characteristics of the brushless motor are changed by switching input of the two or more detection signals to a means for generating an energization signal.