JP3285717B2 - Brushless motor, its driving device, and compressor of air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a brushless motor and its driving apparatus so as to obtain a rotational position signal of the rotor based on the terminal voltage of the stator winding as well as air-sucrose
NA compressors .

[0002]

2. Description of the Related Art For example, as a drive motor for a compressor of an air conditioner, in a case where the capacity of the compressor is required to be variable, it is difficult to control a rotation speed.
Brushless motors have been adopted, and in particular, because of the small number of lead wires, the relative position signal between the stator winding and the permanent magnet type rotor, that is, the rotational position signal, Position sensorless type sensors that detect using an induced voltage induced in the stator winding without using a position sensor have been adopted.

[0003] In this type of brushless motor, when the stator is started, the stator is stopped, and no induced voltage is induced in the stator winding. Therefore, it is necessary to perform a start initialization operation for starting the rotor by some means. For this reason, techniques such as those described in JP-A-57-173385 and JP-A-4-321390 have been disclosed. That is, the techniques disclosed in these publications are configured to apply a constant voltage to a specific phase of a plurality of phases, for example, a three-phase stator winding, for a predetermined time to move the rotor. .

[0004]

In the conventional configuration, a start-up initialization operation for moving a rotor by applying a constant voltage to a specific phase of a stator winding of a brushless motor for a fixed time is performed. The torque generated by applying a voltage to the stator windings of the three phases rapidly overcomes the static friction torque of the rotor, causing the rotor to move rapidly. Was.

The present invention has been made in view of the above circumstances, and an object thereof is to apply a voltage to a specific phase of a stator winding to move a rotor, thereby causing a load to vibrate during a starting initialization operation. Brushless motor and
Compressor of the drive unit as well as the air conditioner of the forefather
To provide a service.

[0006]

Means for Solving the Problems of claims 1 invention, Pal
The voltage applied to the stator winding is controlled by the width modulation control
In the brushless motor, the stator windings include:
A triangular wave voltage with a gradually increasing peak value is equivalently obtained.
So that the voltage with the changed duty ratio
It is configured to be applied .

According to a second aspect of the present invention , a pulse width modulation control is provided.
Brushless motor that controls the voltage applied to the stator windings.
The peak value gradually increases in the stator winding.
In order to obtain a rising sawtooth voltage equivalently,
The voltage with the changed duty ratio is applied at the start.
It is characterized by being constituted as follows .

[0008] A third aspect of the present invention is a brushless motor.
Energize the stator windings of several phases sequentially to rotate the permanent magnet rotor.
Output means for rotating the stator windings,
The rotational position signal of the rotor is obtained based on the pressure,
And supplying an energization timing signal to the output means.
When the brushless motor is started,
In a particular phase of the stator winding,
To supply a timing signal for applying voltage
Motor having control means configured as described above
In the above drive device, the control means may be
Changes the applied voltage to a specific phase in a triangular waveform
And gradually increase the peak value
Supply a timing signal to apply
It is characterized by being constituted as follows .

According to a fourth aspect of the present invention, there is provided a brushless motor
Energize the stator windings of several phases sequentially to rotate the permanent magnet rotor.
Output means for inverting, and terminal voltage of said stator windings
The rotation position signal of the rotor is obtained based on
Providing an energization timing signal to the output means
When the brushless motor is started,
A certain phase of the stator windings
To give the energization timing signal for applying pressure
Of a brushless motor comprising
In the driving device, the control means controls a specific phase at the time of starting.
The voltage applied to the
It is a sawtooth wave of several stages, and its peak value gradually increases
Energizing timing to apply a voltage that raises the
Characterized in that it is configured to provide a
You .

According to a fifth aspect of the present invention , the control means includes a specific phase
The duty of PWM control changes the waveform of the voltage applied to the
Are configured to generate equivalently
It is characterized by that .

[0011] According to a sixth aspect of the present invention , the control means is configured to control a specific phase.
The current applied to the input side of the output means
Is configured to raise until the limiter operates.
It is characterized by that .

[0012] The invention of claim 7 is an air conditioner.
In the compressor, the drive motor of this compressor
Is a brushless motor and this drive motor
The brush according to any one of claims 4 to 7, wherein the driving device is a brush.
It is characterized by using a drive device for a less motor .

[0013]

[0014]

[0015]

[Action]

According to the invention of claims 1 to 4, the rotor torque of the brushless motor in the vicinity of one of the peak values of the voltage waveform applied to the stator winding exceeds the static friction torque of the rotor When the motor starts to move, the voltage decreases, so that the torque generated by the brushless motor decreases to an amount equivalent to the kinetic friction torque of the rotor, so that an appropriate torque acts on the rotor, The child moves slowly.

[0017]

According to the fifth aspect of the present invention , since the waveform of the voltage applied to the specific phase of the stator winding is equivalently generated by the PWM control, it is easy to create the voltage waveform.

According to the invention of claim 6, since the voltage applied to the particular phase of the stator winding is increased to a current limiter is operated, surely the rotor until the current limiter operates Can start moving.

According to the invention of claim 7, or請Motomeko 3 6
Of an air conditioner that exhibits any of the effects of the invention of
A compressor is obtained.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. First, the overall configuration will be described with reference to FIG. The positive and negative terminals of the DC power supply 1 are
A driving circuit 3 is connected to the negative terminal side through a current detecting resistor 2.
Are connected to the input terminals 4 and 5, respectively. Incidentally, the negative terminal of the DC power supply 1 is grounded.

The drive circuit 3 as an output means has input terminals 4 and
5, NPN transistors 6 to 8 and 9 to 11 as semiconductor switching elements are connected in a three-phase bridge. The freewheel diodes 12 to 17 are connected in parallel to the transistors 6 to 11, respectively. The common connection point of the transistors 6 and 9 is connected to the output terminal 18, the common connection point of the transistors 7 and 10 is connected to the output terminal 19, and the common connection point of the transistors 8 and 11 is connected to the output terminal 20. I have.

The brushless motor 21 has a stator 2 having U, V and W phase stator windings 22U, 22V and 22W.
2 and a permanent magnet type rotor (not shown). One terminal of the stator windings 22U, 22V and 22W is commonly connected, and the other terminals are connected to the output terminals 18, 19 and 20 of the drive circuit 3, respectively.

The voltage dividing circuit 23 comprises voltage dividing resistors 24 to 29, and one terminal of each of the stator windings 22U, 22V and 22W, that is, the output terminals 18, 19 and 20 of the driving circuit 3, and the ground. The series circuit of the voltage dividing resistors 24 and 25, the series circuit of the voltage dividing resistors 26 and 27, and the voltage dividing resistor 28
And 29 are connected in series. The common connection points of the voltage dividing resistors 24 and 25, the voltage dividing resistors 26 and 27, and the voltage dividing resistors 28 and 29 are connected to the detection terminal 30,
31 and 32.

Reference voltage generating circuit 3 serving as reference voltage generating means
Reference numeral 3 includes resistors 34 and 35 for voltage division, which are connected between the positive terminal and the negative terminal of the DC power supply 1.
The common connection point of the resistors 34 and 35 is used as a reference terminal 36.

The resistance ratio between the voltage dividing resistors 24, 26 and 28 of the voltage dividing circuit 23 and the voltage dividing resistors 25, 27 and 29 is K
2 (where K is a natural number), and the resistance value ratio between the resistors 34 and 35 of the reference voltage generating circuit 33 is (K + 1): 1.
Is set to

The detecting means 37 comprises the voltage dividing circuit 23 and three comparators 38, 39 and 40. In each of the comparators 38, 39 and 40, each non-inverting input terminal (+) has a voltage dividing voltage. The inverting input terminals (-) of the circuit 23 are commonly connected to the reference terminal 36 of the reference voltage generation circuit 33.

The control device 41, which is a control means, is composed of a microcomputer and its peripheral circuits. For the sake of convenience, the main control circuit 42, voltage command generation circuit 43, pulse width Modulation (PW
M) A signal generation circuit 44 is provided. Then, in the main control circuit 42, the three input ports I1, I2 and I
3 is connected to each output terminal of the comparators 38, 39 and 40, the other two input ports I4 and I5 are connected to each output terminal of the PWM signal generating circuit 44 and the mode setting unit 45, and the six output ports O1 O6 are connected to respective bases of the transistors 6 to 11 via a base drive circuit, and the other two output ports O7 and O8 are connected to respective input terminals of a voltage command signal generation circuit 43 and a PWM signal generation circuit 44. Have been. Incidentally, a start signal ST for starting the brushless motor 21 is supplied to one input port I6 of the main control circuit 42.

In this case, the main control circuit 42
a and a ROM 42b.
A program for controlling the operation of the brushless motor 21 is stored, and the first program shown in FIGS.
The fifth to fifth startup initialization operation modes are stored. The mode setting unit 45 supplies the main control circuit 42 with a mode setting signal for selectively setting one of the first to fifth start-up initialization operation modes stored in the ROM 42b. . Further, the voltage command signal generation circuit 43
, A speed command signal SV is supplied to another input terminal, and an output terminal is connected to an input terminal of the PWM signal generation circuit 44.

Next, the operation of the present embodiment will be described with reference to FIGS. Brushless motor 21
During rotation of the stator windings 22U, 22V and 2
The terminal voltages UV, VV and WV of 2 W are divided by the voltage dividing circuit 23 and detected as detection voltages UVa, VVa and WVa, and these are inputted to the non-inverting input terminals (+) of the comparators 38, 39 and 40. You. The power supply voltage E of the DC power supply 1 is divided by the reference voltage generation circuit 33 and output as a reference voltage VR, which is input to the inverting input terminals (-) of the comparators 38 to 40.

The comparators 38, 39 and 40 compare these detection voltages UVa, VVa and WVa with the reference voltage VR to detect zero-cross points of induced voltages induced in the stator windings 22U, 22V and 22W. I do.

Here, the principle of detecting the rotational position signal on behalf of the terminal voltage UV will be described. That is, the comparator 38
As shown in FIG. 2A, the terminal voltage UV and the reference voltage VR
By detecting the cross point with (= E / 2), that is, by detecting the zero cross point of the induced voltage induced in the stator winding 22U, as shown in FIG.
Obtain the phase signal DSU. Then, the main control circuit 42 calculates a time corresponding to an electrical angle of 30 degrees from the phase signal DSU, and shifts the phase signal DSU by the calculated time.
As shown in (c), a rotational position signal PSU is obtained. The main control circuit 42 performs the same processing for the other terminal voltages VV and WV to obtain two rotational position signals.

The main control circuit 42 logically converts these three rotational position signals to obtain base signals as six energization timing signals, and provides these to the bases of the transistors 6 to 11 of the drive circuit 3. Transistor 6
To 11 are turned on and off, so that the stator windings 11U,
Electric current is supplied to 22V and 22W to rotate the rotor.

By the way, the control device 41 performs pulse width modulation (PWM) control so as to adjust the output based on the speed command signal SV during the actual operation.

More specifically, the main control circuit 42 detects a speed detection signal DV indicating the actual rotation speed of the brushless motor 21 based on the rotation position signal obtained by the calculation, and generates a voltage command signal. It is given to the circuit 43. Then, the voltage command signal generation circuit 43 compares the speed command signal SV with the speed detection signal DV, and performs PWM so that the difference between the two becomes zero.
To the PWM signal generation circuit 44.

The PWM signal generation circuit 44 outputs a PWM signal (see FIG. 3 (c)) having a duty corresponding to the duty signal supplied from the voltage command signal generation circuit 43 and supplies it to the main control circuit 42. The main control circuit 42
For example, the transistors 6, 7, and 8 on the positive side of the drive circuit 3
Is modulated by the PWM signal, for example, the terminal voltage UV also becomes a pulse-like voltage as shown in FIG. 3A, and the phase signal DSU obtained by comparing this with the reference voltage VR is also shown in FIG. As shown by DSU ′ in FIG. Therefore, FIG.
As shown in FIG. 2C, the position detection signal PSU cannot be obtained from the phase signal DSU ′ shown in FIG. The same applies to other terminal voltages VV and WV.

Therefore, usually, the main control circuit 42 is configured to permit comparison of the terminal voltage UV and the reference voltage VR only when the PWM signal (pulse signal) is generated (configuration for reading the phase signal DSU '). FIG.
As shown in (d), a continuous phase signal DSU similar to that in FIG. 2 (b) can be obtained. The same applies to other terminal voltages VV and WV.

As described above, while the rotor of the brushless motor 21 is rotating, the rotational position signal of the rotor can be obtained based on the induced voltages generated in the stator windings 22U, 22V and 22W. When the rotor 21 is started, the rotor is stopped, so the stator windings 22U, 22V
And 22W, no induced voltage is generated, and a rotational position signal of the rotor cannot be obtained. Therefore, in the present embodiment, a start initialization operation for moving the rotor of the brushless motor 21 is performed as follows.

(1) First Start Initialization Operation Mode (FIG. 4) The first start initialization operation mode is selectively set by operating the mode setting unit 45, and a start signal ST is supplied to the main control circuit 42. . As a result, the main control circuit 42
The first start initialization operation mode shown in FIG. 4 is read from 42b and stored in the RAM 42a, and the first start initialization operation mode stored in the RAM 42a is executed. This first startup initialization operation mode is performed by setting a predetermined set voltage from 0 (V) to, for example, 25 as shown by a solid line in FIG.
It gradually changes linearly to (V), and the time from 0 (V) to 25 (V) is set to 1 to 2 seconds. The first start initialization operation mode includes:
As shown by a two-dot chain line in FIG.
It may be one that gradually changes linearly from (V) to the set voltage 25 (V).

In execution, the main control circuit 42 supplies a mode signal MD corresponding to the first startup initialization operation mode to the PWM signal generation circuit 44,
The PWM signal generation circuit 44 supplies the main control circuit 42 with a PWM signal such that the first start initialization operation mode can be equivalently obtained by the PWM control.

Therefore, the main control circuit 42 uses the PWM signal supplied from the PWM signal generation circuit 44 to
For example, the transistors 6 and 10 are turned on and off, so that the voltage of the first startup initialization operation mode obtained by the PWM control is a specific phase of the U- and V-phase stator windings 22U, 22V is applied. As a result, when the voltage applied to the U- and V-phase stator windings 22U and 22V, which are the specific phases of the brushless motor 21, and gradually increasing, is the point at which the torque that overcomes the static friction torque of the rotor is generated. , The rotor starts to move.

Thereafter, when the voltage applied to the stator windings 22U and 22V of the brushless motor 21 reaches the set voltage 25 (V), the main control circuit 42 terminates the startup initialization operation, as described above. The transistors 6 to 11 of the drive circuit 3 are turned on and off in accordance with the rotational position signals based on the induced voltages generated in the stator windings 22U, 22V and 22W, and the speed of the brushless motor 21 is changed to the speed command signal SV.
The starting acceleration operation is performed to increase the speed so as to reach the command speed indicated by.

The U- and V-phase stator windings 2,
Set voltage 2 which is the maximum value of the voltage applied to 2U, 22V
5 (V) is a voltage that generates a torque sufficient to start the movement of the rotor, and corresponds to a constant voltage conventionally applied to a specific phase during the startup initialization operation.

(2) Second Start Initialization Operation Mode (FIG. 5) The second start initialization operation mode is selectively set by operating the mode setting unit 45, and a start signal ST is given to the main control circuit 42. . As a result, the main control circuit 42
The second startup initialization operation mode shown in FIG. 5 is read from 42b and stored in the RAM 42a, and the second startup initialization operation mode stored in the RAM 42a is executed. As shown in FIG. 5, this second startup initialization operation mode
It changes from 0 (V) to a set voltage of 25 (V) in a plurality of steps in a triangular waveform. For example, it repeatedly rises 5 (V) at a predetermined slope and drops 2.5 (V) at a predetermined slope. The value gradually increases.

In execution, the main control circuit 42 supplies a mode signal MD corresponding to the second startup initialization operation mode to the PWM signal generation circuit 44,
The PWM signal generation circuit 44 supplies the main control circuit 42 with a PWM signal such that the second startup initialization operation mode can be equivalently obtained by the PWM control. Subsequent operations are the same as those in the first startup initialization operation mode.
When the voltage of the second start initialization operation mode obtained by the PWM control is a specific phase, the U- and V-phase stator windings 22U, 2
Applied to 2V.

(3) Third Start Initialization Operation Mode (FIG. 6) The third start initialization operation mode is selectively set by operating the mode setting unit 45, and a start signal ST is supplied to the main control circuit 42. . As a result, the main control circuit 42
The third startup initialization operation mode shown in FIG. 6 is read from 42b and stored in the RAM 42a, and the third startup initialization operation mode stored in the RAM 42a is executed. As shown in FIG. 6, this third startup initialization operation mode
It changes in a plurality of steps in a sawtooth waveform from 0 (V) to a set voltage of 25 (V).
(V) The rise and fall of 2.5 (V) at a steep slope are repeated, and the peak value gradually rises.

Then, in execution, the main control circuit 42 supplies a mode signal MD corresponding to the third start initialization operation mode to the PWM signal generation circuit 44,
The PWM signal generation circuit 44 supplies the main control circuit 42 with a PWM signal such that the third startup initialization operation mode can be equivalently obtained by the PWM control. Subsequent operations are the same as those in the first startup initialization operation mode.
When the voltage in the third startup initialization operation mode obtained by the PWM control is a specific phase, the U- and V-phase stator windings 22U, 2
Applied to 2V.

(4) Fourth Start Initialization Operation Mode (FIG. 7) The fourth start initialization operation mode is selectively set by operating the mode setting unit 45, and the start signal ST is given to the main control circuit 42. . As a result, the main control circuit 42
A fourth start initialization operation mode shown in FIG. 7 is read from 42b and stored in the RAM 42a, and the fourth start initialization operation mode stored in the RAM 42a is executed. As shown in FIG. 7, this fourth startup initialization operation mode
For example, a saw-tooth waveform is repeated in which the voltage gradually decreases from 2.5 (V) to 0 (V) at a gentle slope, rises 5 (V) at a steep slope, and drops 2.5 (V) at a more gentle slope. The peak value gradually increases up to the set voltage 25 (V).

Then, in execution, the main control circuit 42 supplies a mode signal MD corresponding to the fourth startup initialization operation mode to the PWM signal generation circuit 44,
The PWM signal generation circuit 44 supplies the main control circuit 42 with a PWM signal such that the fourth start initialization operation mode can be equivalently obtained by the PWM control. Subsequent operations are the same as those in the first startup initialization operation mode.
When the voltage in the fourth startup initialization operation mode obtained by the PWM control is a specific phase, the U- and V-phase stator windings 22U, 2
Applied to 2V.

(5) Fifth Start Initialization Operation Mode (FIG. 8) The fifth start initialization operation mode is selectively set by operating the mode setting unit 45, and a start signal ST is given to the main control circuit 42. . As a result, the main control circuit 42
The fifth start initialization operation mode shown in FIG. 8 is read from 42b and stored in the RAM 42a, and the fifth start initialization operation mode stored in the RAM 42a is executed. As shown in FIG. 8, this fifth startup initialization operation mode
The pulse changes in a plurality of stages, for example, a pulse of 3 (V) at first, and a peak value of 1.5 (V) thereafter.
(V) gradually, and the maximum peak value is equal to the set voltage 25.
(V).

In execution, the main control circuit 42 supplies a mode signal MD corresponding to the fifth startup initialization operation mode to the PWM signal generation circuit 44,
The PWM signal generation circuit 44 supplies the main control circuit 42 with a PWM signal such that the fifth start initialization operation mode can be equivalently obtained by the PWM control. Subsequent operations are the same as those in the first startup initialization operation mode.
The voltage of the fifth startup initialization operation mode obtained by the PWM control is a specific phase of the U- and V-phase stator windings 22U, 2U.
Applied to 2V.

The first to fifth modes set by the mode setting unit 45 are used.
The selection of the startup initialization operation mode is appropriately performed according to the type, performance, installation state, and the like of the compressor as a load of the brushless motor 21.

As described above, in the present embodiment, when the brushless motor 21 is started, the ROM of the main control circuit 42
Any one of the first to fifth start-up initialization operation modes stored in the start-up initialization operation mode 42b is selected and set, and the start-up initialization operation for moving the rotor of the brushless motor 21 based on this is set. Was executed.

First, when the start initialization operation is performed in the first start initialization operation mode shown in FIG.
And the linearly rising voltage applied to the specific U and V-phase stator windings 22U and 22V of the W- and W-phase stator windings 22U, 22V and 22W causes the static friction torque of the rotor to increase. Since the rotor starts to move when the overcoming torque is generated, the rotor of the brushless motor 21 is slow, unlike the conventional method in which the generated torque rapidly overcomes the static friction torque and the rotor moves. This causes the compressor, which is the load of the brushless motor 21, to vibrate sharply.

When the start initialization operation is executed in any of the second to fourth start initialization operation modes shown in FIGS. 5 to 7, the U and V phase stator windings 22U and 22V phase Near the peak value of either the triangular or sawtooth voltage applied to the stator windings 22U and 22V, the generated torque overcomes the static friction torque and the rotor starts moving, and thereafter the applied voltage decreases. Therefore, the generated torque is reduced to the amount corresponding to the kinetic friction torque, so that an appropriate torque is applied to the rotor, and the rotor starts the start initialization operation in the first start initialization operation mode. It moves more slowly than in the case.

When the start initialization operation is performed in the fifth start initialization operation mode shown in FIG. 8, the pulse-shaped voltage applied to the U and V phase stator windings 22U and 22V is changed. In the vicinity of any of the peak values, the generated torque overcomes the static friction torque and the rotor starts to move,
Rotor at once (one pulse) because of pulsed voltage
The moving angle becomes smaller, and thus the rotor moves more slowly than in the case of the start initialization operation according to the first start initialization operation mode.

Further, according to the present embodiment, the voltage waveforms of the first to fifth start-up initialization operation modes shown in FIGS. 4 to 8 are equivalently obtained by PWM control. Is easy.

Further, according to the present embodiment, the stator winding 2
Voltages applied to the specific U, V-phase stators U, V-phase stator windings 22U, 22V of the 2U, 22V, and 22W in accordance with the first to fifth start-up initialization operation modes. Is raised to a predetermined set voltage 25 (V), so that a point in time at which the generated torque overcomes the static friction torque of the rotor always occurs before the voltage reaches the set voltage 25 (V). , The rotor can be reliably started to move, and the stator windings 22U,
An unnecessarily large voltage is not applied to 22V.

FIG. 9 shows a second embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. Hereinafter, only different parts will be described. That is, in the current limiter 46, the input terminal is connected to the output terminal of the current detection resistor 2, and the output terminal is connected to the main control circuit 42.
Is connected to the input port I7. The current limiter 46 detects a DC current flowing to the input side of the drive circuit 3, and performs a detection operation to output a detection signal when the DC current reaches a set current. In this case, the DC current flowing to the input side of the drive circuit 3 is
U, 22V and 22W.

Thus, the main control circuit 42 includes the first to fifth
During the startup initialization operation in any one of the startup initialization operation modes (see FIGS. 4 to 8), the stator windings 22U and 22 of specific phases U and V are used.
The voltage applied to V is increased until a detection signal is given from the current limiter 46. The set current detected by the current limiter 46 is
The size is set to generate a torque sufficient for the rotor to start moving by overcoming the static friction torque.

Therefore, according to the second embodiment, the same effects as those of the above embodiment can be obtained. Even in this case, the rotor can be surely started to move, and the specific U , V-phase stator windings 22U, 22V
Unnecessary excessive current is not supplied to the power supply.

In the above embodiment, the stator windings 22U,
The terminal voltages UV, VV and WV of 22V and 22W are compared with the reference voltage VR of the reference voltage generating circuit 33, and a rotation position signal of the rotor is obtained based on the comparison result. As shown in JP-A-6-8510, the terminal voltages UV, V of the stator windings 22U, 22V and 22W are set.
An integrating means (low-pass filter) for integrating V and WV and an integrating means (smoothing circuit) for integrating the neutral point voltages of the stator windings 22U, 22V and 22W are provided. May be obtained.

In addition, the present invention is not limited to the above-described embodiment, but can be modified or expanded as follows. The first to fifth start-up initialization operation modes are stored in the ROM 42b of the main control circuit 42, and one of them is selectively set and executed by the mode setting unit 45. One startup initialization operation mode most suitable for the load may be stored. Specific phases of the stator windings 22U, 22V and 22W of the brushless motor 21 are set to the U and V-phase stator windings 22U and 22V.
The V and W phase stator windings 22V and 22W or the W and U phase stator windings 22W and 22U may be set. A voltage waveform corresponding to the first to fifth start initialization operation modes is represented by PW
Although it is obtained equivalently by the M control, it may be obtained analogously by using the active region of the transistor instead.

[0064]

As described above, the present invention has the following effects.

[0065] According to the invention of claims 1 to 4, triangular voltage (claims peak value gradually increases in the stator winding
1, 3) or sawtooth voltage (Claims 2 and 4)
Is applied, the voltage decreases when the generated torque of the brushless motor overcomes the static friction torque of the rotor and the rotor starts to move near any peak value of the voltage waveform, The generated torque is reduced to a value corresponding to the dynamic friction torque, so that an appropriate torque acts on the rotor, and the rotor moves slowly.

[0066]

According to the fifth aspect of the present invention , since the waveform of the voltage applied to a specific phase of the stator winding is equivalently generated by PWM control, it is easy to create a voltage waveform. .

[0068]

According to the sixth aspect of the present invention , the voltage applied to a specific phase of the stator winding is increased until the current limiter operates. The movement of the rotor can be reliably started.

[Brief description of the drawings]

FIG. 1 is an electrical configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram illustrating the principle for obtaining a rotational position signal.

FIG. 3 is a waveform diagram of each part.

FIG. 4 is a diagram showing a first startup initialization operation mode;

FIG. 5 is a diagram showing a second startup initialization operation mode;

FIG. 6 is a diagram showing a third startup initialization operation mode;

FIG. 7 is a diagram showing a fourth startup initialization operation mode;

FIG. 8 is a diagram showing a fifth startup initialization operation mode;

FIG. 9 is an electrical configuration diagram showing a second embodiment of the present invention.

[Explanation of symbols]

In the drawing, 3 is a drive circuit (output means), 21 is a brushless motor, 22 is a stator, 22U to 22W are stator windings, 37 is detection means, 41 is a control device (control means), 4
2 is a main control circuit, 43 is a voltage command signal generation circuit, 44 is a PWM signal generation circuit, and 46 is a current limiter.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02P 6/18

Claims (7)

(57) [Claims] 1. A method for controlling a stator winding by pulse width modulation control.
In a brushless motor for controlling an applied voltage, a triangular wave voltage whose peak value gradually increases is equivalently obtained in the stator winding.
So that the voltage with the changed duty ratio
Characterized by being configured to be applied
Sumota. 2. A method for controlling a stator winding by pulse width modulation control.
In a brushless motor for controlling an applied voltage, a voltage of a sawtooth wave whose peak value gradually increases is equivalently applied to the stator winding.
Start the voltage with the changed duty ratio to obtain
Characterized in that it is adapted to be applied at times.
Siles motor. 3. A plurality of stator windings for a brushless motor.
To rotate the permanent magnet type rotor by energizing
Force means, and rotation of the rotor based on a terminal voltage of the stator winding.
A position signal is obtained, and the output means is energized in response to the position signal.
Signal and start the brushless motor.
In operation, a particular phase of the multi-phase stator windings
Energizing tie for applying a voltage that gradually increases
Control means configured to provide a
In the brushless motor drive device provided with the control device, the control means may control the power applied to a specific phase at the time of starting.
The pressure is changed in a triangular wave
Voltage to gradually increase the peak value.
Drive characteristics and to Lube Rashiresumota that it is configured to provide energization timing signal. 4. A plurality of stator windings for a brushless motor.
To rotate the permanent magnet type rotor by energizing
Force means, and rotation of the rotor based on a terminal voltage of the stator winding.
A position signal is obtained, and the output means is energized in response to the position signal.
Signal and start the brushless motor.
In operation, a particular phase of the multi-phase stator windings
Energization timing for applying a voltage that gradually increases
Control means configured to provide a signaling signal.
In the above-mentioned brushless motor driving device, the control means starts up a voltage applied to a specific phase at the time of starting.
Multi-step sawtooth with sharp steepness and gentle fall
Like, gradually increasing its peak value
To supply a timing signal for applying voltage
Drive characteristics and to Lube Rashiresumota that it is configured to. 5. The control means according to claim 1, wherein said control means comprises means for controlling a voltage applied to a specific phase.
By changing the duty of PWM control, etc.
Characterized in that it is configured to generate
The driving device for a brushless motor according to claim 3 or 4 . 6. The control means outputs an applied voltage to a specific phase.
The current limiter that detects the current on the input side of the
Characterized by being configured to rise up to
A driving device for a brushless motor according to any one of claims 3 to 5 . 7. A compressor for an air conditioner.
And the drive motor of this compressor is a brushless motor.
And the drive device of this drive motor
Item 7. Driving the brushless motor according to any one of Items 3 to 6
Air conditioner unit characterized by using a device
Impreza.