JPS6185090A - Synchronous operation unit for brushless motor - Google Patents

Abstract

PURPOSE:To equalize the load share of a plurality of motors by operating the motors by a torque control system which inputs the same torque command signal as an input signal, and mechanically coupling the motors by a reduction gear. CONSTITUTION:The first control system of a main control system is composed of a detector 13, an error amplifier 14, a converter 15-1, a drive circuit 16-1, a brushless motor 10-1 and a resolver 11-1, the second control system of a sub control system is composed of a converter 51-2, a drive circuit 16-2, a brushless motor 10-2, and a resolver 11-2, and the third control system of the sub control system is composed of a converter 15-3, a drive circuit 16-3, a brushless motor 10-3, and a resolver 11-3. The motors 10-1-10-3 are mechani cally coupled by a reduction gear 20 so as not to cause mechanical angle dis placement.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to a plurality of brushless electric appliances! This invention relates to a synchronous operation device for brushless motors that generates large output torque by synchronously operating IJ machines.

[Prior Art] As a brushless electric motor, a rotating field type motor generator with field poles made of permanent magnets as a rotor has features such as no brushes that wear out and no commutator that requires maintenance.
ii. By using a rod position detector and a drive circuit, it is widely used as a control motor in the field of machine tools and robots because it can exhibit control performance equivalent to or better than conventional DC motors. It is used.

Recently, as processing speeds such as metal press processing have become faster, productivity has been improved by increasing the feed speed in the workpiece conveyance process. Brushless motors have come to replace conventional DC motors.

When using this brushless motor in a conveyor, recent high-speed feed conveyors have increased mechanical strength, so the load inertia moment of the motor shaft is large, and in order to shorten the production process, high-frequency intermittent operation is required. = ! I! I.J.
The operating conditions for the machine are severe. Therefore, in order to meet these operating conditions, conventionally a plurality of speed control systems using electric motors have been operated in parallel.

[Problems to be Solved by the Invention] However, when multiple speed control systems are operated in parallel, due to non-uniformity of the speed detectors installed in each motor, changes over time, etc. The distribution of cylinders becomes uneven, and as a result, the resulting motor may share a load larger than its capacity, which has the disadvantage of increasing the number of parallel motors to perform parallel operation, which makes it less economical. I became a high school teacher, and there were some complicated problems.

An object of the present invention is to provide a synchronous operation device for brushless motors that can prevent uneven load sharing among the motors even when a plurality of brushless motors are operated in parallel, and that can improve the reduction rate of motor capacity. It is on offer.

[Means for Solving the Problems] The first invention of the present application includes first to nth (n is a positive integer of 2 or more) control systems that operate synchronously, and A reduction gear that meshes the individual output gears connected to the rotor of each brushless electric motor in the control system with the teeth of the common output means to output a sum of rotational force, and connects each of the brushless electric motors so that no mechanical angular deviation occurs. In the synchronous operation device for a brushless motor, the first control system includes a first brushless motor to be controlled, a first resolver and a speed detector connected to a rotor of the motor, and a first brushless motor to be controlled. ,
a detection section that detects a voltage difference between a speed command signal given from the outside and a speed signal output from the speed detector; and an error amplifier that amplifies the voltage difference output from the detection section and outputs a torque command signal. a conversion circuit that converts the torque command signal and the detection signal eo output from the resolver to output three-phase current Iu multiple signals U, IV, [W; and the three-phase current command signal Iu, ■With v and Iw as input signals, the armature current i is proportional to the voltage value of these signals.
a drive circuit that supplies u, iv, and i* to the stator winding of the brushless motor, and the n-th control system supplies the n-th brushless motor to be controlled and the rotor of the motor. Conversion of a connected n-th resolver and a torque command signal of the first control system as an input signal, converting the torque command signal and a detection signal output from the resolver to output a three-phase current command signal. and a drive circuit that uses the three-phase current command signal as an input signal and supplies a three-phase armature laminar flow proportional to the voltage value of the signal to the stator winding of the n-th brushless motor. It is characterized by the presence of

A second invention of the present application includes first to nth (n is a positive integer of 2 or more) control systems that operate synchronously, and the rotor of each brushless motor of the first to nth control systems A brushless electric motor comprising a reducer which meshes the connected individual output tooth widths with the teeth of a common output means to output a sum of rotational force and connects each of the brushless electric rocks so as not to cause mechanical angular deviation.

In such a synchronous operation device, the first control system includes a first brushless electric motor to be controlled, a first resolver and a speed detector connected to the rotor of the electric motor, and a speed applied from the outside. a detection unit that detects a voltage difference between a command signal and a speed signal output from the speed detector; an error amplifier that amplifies the voltage difference output from the detection unit to output a torque command signal; a conversion circuit that converts the detection signal eo outputted from the resolver and outputs three-phase current command signals Ill, IV, I-, and the three-phase current command signals +1. Using IV and IW as input signals, electron currents iu, iv, which are proportional to the voltage values of these signals, are generated.
iw to the stator winding of the brushless motor, and the n-th control system controls the n-th brushless motor to be controlled and the three-phase current command signal Ill of the first control system. , IV, [ as input signals, three-phase electric currents iu, iv, iw proportional to the voltage values of the signals are applied to the n-th brushless electric current! ! This is characterized in that it is comprised of a drive circuit that supplies the stator windings of 11 machines.

[Action of the invention] The effects of the main points related to the invention of the present application will be described.

In the first invention, the torque command signal Et of the first control system, which is the main control system, is used as an input signal to the n-th control system, which is the slave control system, and the first to n-th brushless electric motors are mechanically controlled. Since it is operated by connecting with a reducer to prevent angular deviation,
Brushless E fj R can be operated synchronously.

In the second invention, the current command signals (II, IV, IW) of the first control system, which is the main control system, are input signals of the n-th control system, which is the slave control system, and the first to n-th brushless motors are The brushless motors can be operated in a synchronized manner by connecting them with a reduction band to prevent mechanical angular deviation.

[Example] Hereinafter, the present invention will be described in detail based on the drawings. FIG. 1 is a block diagram showing an embodiment of the first invention of the present application. In the figure, 10-1゜10-2.10-3 is a brushless electric current f! which outputs rotational force by armature currents iu, iv, iw to the stator windings. lI Akebono, 11-1.1
1-2.11-3 is connected to the rotating shaft of the brushless motor, and the rotation angle θm is connected to the rotating shaft of the brushless motor to detect the magnetic pole position of the motor.
The detection signal eO has a change in electrical phase shift in response to a change in
Resolver that outputs, 12 is electric! b A speed detector 1 connected to the rotating shaft of FM 10-1 and outputting a speed signal Et(l) having a voltage value proportional to the rotational speed c3m.
3 is a detection unit that outputs a differential voltage △E between the speed command signal E com output from a speed setting device (not shown) and the speed signal Etg of the speed detector 12 \ etc.; This is an error amplifier that amplifies E to the output differential voltage and outputs a torque command signal Et.

15-1.1572.15-3 is each resolver 1.
1-1.11-2.11-3, respectively, and the torque command signal E[] are used as input signals to generate a three-phase current command signal IU.

This is a conversion circuit that outputs IV and IW respectively.

16-1.16-2.16-3 is the conversion circuit 15-1
．． Using the three-phase current command signals II, IV, and IW outputted from the motors 10-1. This is a drive circuit that supplies the stator windings of 10-2 and 10-3 respectively. These drive circuits 16-1.
16-2゜16-3 C, three-phase current command signal IU, IV
, a current detection unit 17 that detects the current difference for each phase between IW and three-phase armature currents iu, iv, and iw, and performs processing such as pulse width modulation on the current difference for each phase to perform power amplification, respectively. and three-phase armature current iu, iv.

A power amplifier circuit 18 that outputs iw and a three-phase armature current i
The current detection unit 17 detects u, iv, and 'iw, respectively.
and a current detector 19 (provided for the U phase, ■ phase, or three phases) that inputs the current to each phase.

20 is the brushless electric motor 1110-1.10-2.1
Individual output gears 21-1, 21-2 and 21-3 are connected to the rotor 0-3 and transmit the rotational force of each tan, and a Add each brushless motor 10-1.10-
2.10-3 is a speed reducer equipped with a common output gear 22 as a common output means that connects 10-3 so as not to cause mechanical angular deviation, and an output shaft 23 connected to this common output gear 22.

Such a device includes a detection unit 13. Error amplifier 14, conversion circuit 151. Drive circuit 16-1. brushless motor 10
-1. The resolver 11-1 constitutes a first control system which is a main control system, and the conversion circuit 15-2. Drive circuit 16-
2. Brushless t-tater 10-2. The resolver 11-2 constitutes a second control system which is a secondary control system, and the converter circuit 15-3. Drive circuit 16-3. Brushless motor 10-
3. The resolver 11-3 constitutes a third control system which is a subordinate control system.

Next, the operation shown in FIG. 1 will be explained. First, the first control system inputs the speed command signal E C0II+ to the detection unit 13, obtains the difference voltage E from the speed signal Etg, and amplifies the difference voltage E with the error amplifier 14 to generate the torque command signal. @Et is obtained, and this signal Et and the detection signal e from the resolver 11-1 are
A three-phase current command signal 1u, which has an amplitude value proportional to the voltage value of the signal Et, is obtained by converting the signal Et and o by the conversion circuit 15-1.
Iv, B are obtained, and using these signals Ill, IV, IW as input signals, electric currents iu, iv, iw having amplitude values proportional to the voltage values of these signals are sent from the drive circuit 16-1 to the brushless electric motor 110-1. When supplied to the stator winding of
A rotational force having a rotational speed N is generated in the brushless electric motor 10-1, and the rotational force is transmitted to the gear 21-1 of the reduction gear 20. This first control system uses a speed command signal E
It operates as a speed control system that outputs a rotational speed N proportional to com, and inputs a torque command signal Et to the next second (third) control system.

Next, the second (third) control system outputs the torque command signal E.
t is an input signal, and this signal Et and the resolver 11-2
(11-3) from the detection signal eo and the conversion circuit 15-
2 (15-3) to convert the signal to produce a three-phase current command signal II, [V,
I-, and these signals Ik1. A drive circuit 16-2 (1
6-3) When supplied to the stator winding of the 11 electric motors 10-2 (10-3), a rotational force of rotation speed N is generated in the electric motor 10-2 (10-3), and the rotational force is decelerated. 120 gears 21-2 (21-3).

Above 1. Second. The third control system applies rotational force to each gear 21-1.2 at a rotational speed N proportional to the same torque command signal Et.
1-2, 21-3 are driven, each rotational force is added by the output gear 22, and the total rotational force is output to the output shaft 23.

An example of the internal configuration of the conversion circuit 15-1.15-2.15-3 described above is shown in FIG. In this conversion circuit, the oscillator O8C is turned on, and the two-phase sine wave <i number ex, ey outputted from the oscillator O8C is input to the two-phase excitation windings 11A and 11B of the resolver 11. . The detection signal eo, which has a change in electrical phase shift as the rotation angle θm of the rotation shaft 11C of the resolver 11 changes, is transmitted to the detection winding 110.
is output from. The detection signal en and the two-phase sine wave signal ex
.

and ey respectively by multipliers M1. Multiply by M2 and pass the signal EC through the low-pass filter LFI, LF2.

Output ES. As is well known, the signals EC and Es are EC=
Sin(θe+ (7r/2)), Es = sinθe
(Here, θe=θm/P, P is the number of pole pairs of the resolver). These signals EC, ES and the torque command signal Et are respectively applied to multipliers M3. A two-phase current command signal Iα multiplied by M4 and proportional to the voltage value of the signal Et.

Iβ is converted into 1q, and these signals Iα and ■β are converted into three-phase current signals (U, IV, lWk: by a two-phase/three-phase converter C0NV. This two-phase/three-phase converter C0NV is shown in the vector diagram in Fig. 3. As shown in Figure 1, the α and α phases are in phase, and the ■ and W phases are obtained by performing vector synthesis of the α and β phases using an operational amplifier. Phase sine wave j:j bow CX, -.

ey is omitted for simplification.

FIG. 4 is a block diagram showing an embodiment of the second invention of the present application. In the figure, parts corresponding to those in FIG. 1 are designated by the same reference numerals. To explain its operation, the first
The control system transmits the speed command signal E C0I11 to the detection unit 13.
and the difference voltage ΔE with the speed signal Etg is amplified by the error amplifier 14 to obtain the torque command signal Et.
A conversion circuit 15-1 performs signal conversion from the detection signal eo from the resolver 11-1 to obtain three-phase current command signals Jul, IV, and IW having amplitude values proportional to the voltage value of the signal Et. Using the signals IU, IV, and IW as input signals, armature currents iu and iV have amplitude values proportional to their voltage values.
, iW is supplied from the drive circuit 16-1 to the stator winding of the electric motor 10-1, a rotational force having a rotational speed N is generated in the electric motor 10-1, and the rotational force is transmitted to the gear 21-1 of the reducer 20. It's meant to be transmitted. This control system uses a speed command signal E
It operates as a speed control system that outputs a rotational speed N proportional to com, and inputs three-phase current command signals Ill, IV, 114 to the next second (third) control system.

The second (third) control system includes the three-phase current command signals IU, [
The armature current iu has an amplitude value proportional to the voltage value of these signals with V and I- as input signals.

When iv and iw are supplied from the drive circuit 16-2 (16-3> to the stator winding of the motor 10-2 (10-3), η
Electric motor 10-2 (10-3> generates a rotational force with a rotational speed N, and the rotational force is reduced by gear 21-2 (21
-3).

Above 1. Second. The third control system uses the same current command signals IU, IV, ! - Each individual output gear 21-1.21-2.21-3 is driven by a rotational force with a rotational speed N proportional to It is output to the shaft 23.

In the above embodiment, the common output gear 22 is used as the common output means of the reduction gear 20, but as shown in FIG. 5, the common output rack gear 24 is used as the common output means, and the common output rack gear 24 is moved. Alternatively, the common output rack gear 24 may be fixed and the individual output gears 21-1 to 21-3, which are mechanically integrated, may be moved. All of these satisfy the synchronous operation conditions for brushless motors.

Further, in the above embodiment, the speed detector 12 is directly connected to the electric motor, but it does not necessarily have to be directly connected as long as the rotational speed can be detected.

Furthermore, in the above embodiment, the case where there are two slave control systems is shown, but the number of slave control systems is two! It goes without saying that the number of III In systems is not limited to 2, and may be 1 or 3 or more.

[Effects of the Invention] As explained above, the synchronous operation device for a plurality of brushless motors according to the first (or second) invention of the present application uses the same torque command signal Et (or a current command proportional to the output torque of the motor). Signal IU, IV.

Multiple brushless motors are operated by a torque control system using IW) as an input signal, and these brushless motors are mechanically connected with deceleration to prevent mechanical angle distortion. It is possible to equalize the load sharing of the electric motors. According to experiments, the conventional load sharing ratio is 8
However, according to the present invention, the load sharing ratio is 9%.
It was confirmed that the load sharing ratio could be improved. Therefore, according to the present invention, electric #J
The number of machines can be selected according to the load of 1-Luke, which is economical. Also, 1st. According to the second invention, the speed detector can be omitted in the secondary control system, and in the second invention, the secondary control system can also omit the resolver and the conversion circuit in addition to the speed detector. It is possible to construct the device economically.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the brushless electric synchronous operation device according to the first invention, Fig. 2 is a block diagram showing an embodiment of the conversion circuit, and Fig. 3 is for explanation of Fig. 2. 4 is a block diagram showing an embodiment of the synchronous operation device for a brushless motor according to the second invention, and FIG. 5 shows an example of the individual output gears of the reducer and the pond of the common output means.
” is a side view. 10-1.10-2.10-3...Brushless electric motor, 11-1.11-2.11-3...Resolver, 12
... Speed detector, 13... Detection unit, 14... Error amplifier, 15-1.15-2.15-3... Conversion circuit, 16-1.16-2.16-3. ...Drive circuit, 20
...Reduction code, 21-1.21-2.21-3...Individual output m wheel, 22...Common output gear as common output means, 23...Output shaft. °Figure 1 Figure 2

Claims (2)

[Claims] (1) Comprising first to nth (n is a positive integer of 2 or more) control systems that operate synchronously, and an individual output connected to the rotor of each brushless motor of the first to nth control systems. A synchronous operation device for a brushless motor, comprising a reduction gear that meshes gears with teeth of a common output means to output a sum of rotational force and connects each of the brushless motors so as not to cause mechanical angular deviation. The first control system is the first control system to be controlled.
a brushless electric motor, a first resolver and a speed detector connected to the rotor of the electric motor, and detection for detecting a voltage difference between a speed command signal given from the outside and a speed signal output from the speed detector. an error amplifier that amplifies the differential voltage output from the detection section and outputs a torque command signal; and a three-phase current command that converts the torque command signal and the detection signal e_0 output from the resolver. A conversion circuit that outputs signals IU, IV, and IW, and armature currents iu, iv, and iw proportional to the voltage values of these signals using the three-phase current command signals IU, IV, and IW as input signals, are fixed to the brushless motor. The n-th control system includes an n-th brushless motor to be controlled and an n-th brushless motor connected to the rotor of the motor.
a converter circuit that uses the torque command signal of the first control system as an input signal, converts the torque command signal and the detection signal output from the resolver, and outputs a three-phase current command signal; and a drive circuit that uses a phase current command signal as an input signal and supplies a three-phase armature current proportional to the voltage value of the signal to the stator winding of the n-th brushless motor. Synchronous operation device for electric motors. (2) comprising first to nth (n is a positive integer of 2 or more) control systems that operate synchronously, and an individual output connected to the rotor of each brushless motor of the first to nth control systems; A synchronous operation device for a brushless motor, comprising a reduction gear that meshes gears with teeth of a common output means to output a sum of rotational force and connects each of the brushless motors so as not to cause mechanical angular deviation. The first control system is the first control system to be controlled.
a brushless electric motor, a first resolver and a speed detector connected to the rotor of the electric motor, and detection for detecting a voltage difference between a speed command signal given from the outside and a speed signal output from the speed detector. an error amplifier that amplifies the differential voltage output from the detection section and outputs a torque command signal; and a three-phase current command that converts the torque command signal and the detection signal e_0 output from the resolver. A conversion circuit that outputs signals IU, IV, and IW, and armature currents iu, iv, and iw proportional to the voltage values of these signals using the three-phase current command signals IU, IV, and IW as input signals, are fixed to the brushless motor. and a drive circuit that supplies the child winding, and the n-th control system inputs the n-th brushless motor to be controlled and the three-phase current command signals IU, IV, and IW of the first control system. and a drive circuit that supplies three-phase armature currents iu, iv, iw proportional to the voltage values of the signals to the stator windings of the n-th brushless motor. Synchronous operation device.