JP3183071B2 - Control drive device for sensorless DC brushless motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensorless DC having no position detector such as a Hall element or a rotary encoder.
The present invention relates to a control and driving device for a brushless motor.

[0002]

2. Description of the Prior Art As shown in FIG.
C, signals (7-a, 7-b , 7-c) obtained by phase-shifting (retarding) the back electromotive force of each phase by about 90 °, and neutral point potential (8)
To obtain the angular position information of the rotor as three digital signals (9-a, 9-b, 9-c). From the respective signals, the energization signal of the phase is obtained. However, the energization signal of a phase different from the phase is obtained.

[0003] Generally, in the case of a sensorless DC brushless motor, it is impossible to always detect only the back electromotive force due to the energization of the stator windings. Is duplicated with the energizing voltage, and must be processed by a filter or the like in a circuit, and is due to signal transmission delay characteristics of the filter or the like.

The signal transmission delay characteristic is described in
In the case of 9-36519, by setting the phase difference to 90 °, the C-phase energizing signal is obtained from the A-phase output.
The A-phase energizing signal is obtained from the B-phase output, and the B-phase energizing signal is obtained from the C-phase output.

Here, in general, in the case of a 120 ° conduction method, by setting the phase difference to 90 ° , the phase and the phase are controlled.
The energization signals of different phases can be obtained. By setting the angle to 30 °, an energization signal of the phase can be obtained.

In Japanese Patent Publication No. 59-36519, the obtained digital signals (9-a, 9-b, 9-
With the change in c) as a trigger, the switching elements are turned on and off in a predetermined pattern, the energization pattern to each phase of the stator winding is switched, and the motor is controlled and driven.

[0007] Also, (9-a, 9-b, 9-
As is clear from c) and (10), between the input of the trigger and the change of the energization pattern to the stator winding,
In particular, no delay angle is provided, and the energization pattern is switched simultaneously with the trigger input.

Further, the phase shift of the back electromotive force is set to the retarded angle of 90 ° as described above.

[0009]

However, when the motor is actually driven by the above-described conventional method, the following problems occur.

The first problem is that, in FIG. 3, the switching element 1 is used to turn on and off the current supply to the stator winding 2.
When turning off, a surge voltage is generated from the winding at the time of OFF,
In order to absorb this, the return diode 3 is usually connected in parallel to the switching element 1, and the amount of the phase shift of the back electromotive force tends to be more advanced than the set value due to the effect of the return current flowing through this diode. As a result, there is a problem that the energization timing to the stator winding is shifted and motor efficiency is deteriorated. Since the return current changes according to the load, the shift of the phase shift amount also changes according to the load.

FIG. 4 shows the state of the phase shift due to the return current. The dotted line shows the case where there is no return current, and the solid line shows the voltage waveform of each part in FIG. 3 when there is the return current. FIG. 6 shows a voltage waveform of the phase terminal when the energization timing is advanced by about 30 ° from the optimum point.

The second problem is that the phase shift in FIG.
The integration circuit (filter circuit) that performs
The lower the frequency, the more the phase is advanced.
As a result, the energization timing is shifted, and the motor efficiency is reduced.
There was a problem of getting worse.

Here, the frequency characteristic of the above-described integrating circuit is
This will be described with reference to FIG. FIG. 5 shows the integration circuit in FIG.
(Phase shift unit)
It is.

FIG . 5A shows a case where the frequency is high.
(B) is a case where the frequency is low. However, input wave
The shape is a square wave for easy understanding
Is actually the waveform input from the motor terminal,
The principle of advancing does not change.

First, when the frequency shown in FIG.
Indicates that the output phase is zero-cross
It is delayed about 90 ° from the vicinity. Therefore, the output of the comparison circuit
The force is also a signal delayed by 90 °, and the phase originally intended
The shift amount.

However, as shown in FIG.
The time constant of the integrating circuit approaches the period of the input signal.
The linearity of the output of the integrating circuit decreases,
The delay is about 60 ° on a near basis.
This is more advanced than the illustrated phase shift amount.

As described above, generally, resistors and capacitors are used.
In the integration circuit, the lower the frequency of the input
With the characteristic that the phase of the output signal advances
I have.

To reduce this, the time constant must be
It must be set to be large enough for the period.
However, in that case, there is a problem that the amplitude becomes small.
You.

As described above, since the deviation of the phase shift amount of the back electromotive force from the originally intended set value greatly varies depending on the load and the number of revolutions, for example, the air conditioner for an electric vehicle having an extremely large load variation. When the electric compressor motor is driven, the effect is remarkable, and as a result, there is a problem that the power load on the battery increases and the traveling distance of the vehicle decreases.

[0020] Do the third problem, when the deviation from the set value of the phase shift amount described above, attempts to circuit corrected by hardware, changing the time constant according to the frequency
Which very complicated circuit configuration increases the cost. In addition, when attempting to control and drive motors having different load conditions, a hardware change is required each time, and there is a problem that the change is time-consuming.

The fourth problem is that of Japanese Patent Publication No. 59-36519.
In the circuit as shown in, when performing the phase shift of the counter electromotive force, the nature of the CR circuit, can not be a 90 ° other than phase shift, for example, a low load, high rotation gutter
The third signal is the most likely to retard the back electromotive force.
In this case, there has been a problem that it is not possible to softly correct the energization timing so as to be optimal by the delay from the input of the third signal.

The present invention solves the above-mentioned problems, and uses a low-cost structure to prevent the motor efficiency from deteriorating due to fluctuations in load and rotation speed, to always operate the motor near the maximum efficiency, and to use an electric vehicle. It is an object of the present invention to provide a control and drive device for a sensorless DC brushless motor that can extend the running distance as much as possible and can easily cope with driving motors with different load conditions.

[0023]

(1) When a DC voltage is supplied and a permanent magnet rotor is rotated, a back electromotive force induced in each phase of a three-phase connected stator winding is detected. By detecting the angular position of the rotor,
A control and driving device for a sensorless DC brushless motor that switches an energization pattern to each phase of the stator winding, wherein a first signal in which the phase of the back electromotive force is shifted, and a zero potential of an AC component of the first signal And the second signal in the vicinity,
A third digitized signal obtained by the comparison is output, and the absolute value of the phase shift with respect to the back electromotive force of the third signal is set to 90 ° or 30 °.
And a control unit that switches a current supply pattern to each phase of the stator windings with a change in a third signal output from the position detection circuit as a trigger. In the control unit, after the third signal changes, delay until the rotor advances by a predetermined angle,
An energization delay angle for switching the energization pattern is provided.

(2) In addition to the configuration of the means (1) for solving the above-mentioned problem, the present invention further comprises a current detecting means for detecting a current flowing through the stator winding or a DC current supplied from a DC voltage. And a control unit for changing the conduction delay angle in accordance with the current.

(3) In addition to the configuration of the means (1) for solving the above-mentioned problem, a voltage detecting means for detecting a DC voltage and a current detecting means for detecting a DC current supplied from the DC voltage are provided. A control unit for detecting power consumption from the voltage and the current, and changing an energization delay angle in accordance with the power consumption.

(4) In addition to the configuration of the means (1) for solving the above-mentioned problem, the DC voltage is a DC voltage obtained by rectifying an AC voltage, and an AC current supplied from the AC voltage is detected. And a control unit for changing the conduction delay angle in accordance with the current.

(5) In addition to the configuration of the means (1) for solving the above problem, the DC voltage is a DC voltage obtained by rectifying an AC voltage, and a voltage detecting means for detecting the AC voltage; A device provided with current detection means for detecting an alternating current supplied from an alternating voltage, detecting a power consumption from the voltage and the current, and providing a control unit for changing a conduction delay angle in accordance with the power consumption. It is.

(6) In addition to the configuration of means (1) and (2) and (3) and (4) and (5) for solving the above-mentioned problem, a third output from the position detection circuit is provided. A control unit is provided which detects the rotation speed of the rotor from the cycle or frequency of the signal and changes the energization delay angle in accordance with the rotation speed.

(7) The means for solving the above problems (1), (2), (3), (4), (5), and (6), wherein the position detection circuits are based on the minus potential of the DC voltage. With a back electromotive force of each phase induced in the stator winding as an input, a voltage dividing section for converting the voltage level of the back electromotive force, and an AC coupling section for removing a DC component of the back electromotive force. A back electromotive force detection circuit, an integration circuit that integrates and performs a phase shift on each phase voltage output from the back electromotive force detection circuit, and a voltage of each phase output from the integration circuit; Each output is composed of a comparison circuit that compares the output with the remaining two-phase combined voltages different from each other.

(8) Means for Solving the Problems (1) and (2) and (3) and (4) and (5) and (6) and (7) are constituted by a microcomputer. It was done.

(9) The third signal output from the position detection circuit of the means (8) for solving the above problem is
This is input to the external interrupt terminal of the microcomputer.

(10) Means for solving the above problems (1) and (2) and (3) and (6) and (7) and (8) are mounted on an electric vehicle. An electric compressor motor which receives from a battery and air-conditions the electric vehicle is controlled and driven.

[0033]

According to the present invention, (1) the amount of phase shift with respect to the back electromotive force of the third signal, which fluctuates depending on the load or the number of revolutions, is set in advance on the leading side of the fluctuation range. When switching the energization pattern to each phase of the stator winding with the change of the third signal as a trigger, an energization delay angle is provided to delay until the rotor advances by a predetermined angle, so that energization timing is circuit-wise. Instead of being fixed at a fixed timing, it is possible to set the timing at an arbitrary timing, so that the motor can always be operated near the maximum efficiency.

(2) Since the energization delay angle is changed according to the DC load current or the AC load current, the relationship between the DC load current or the AC load current and the shift amount of the phase shift is grasped in advance. In advance, by changing the energization delay angle so as to correct it, the motor can always be operated near the maximum efficiency.

(3) Since the energization delay angle is changed in accordance with the power consumption, the relationship between the power consumption and the phase shift deviation amount is grasped in advance, and the energization delay angle is corrected so as to correct it. By changing the angle, the motor can always be operated near the maximum efficiency.

(4) Since the energization delay angle is changed according to the AC current of the power supply source, the relationship between the AC current and the amount of phase shift deviation is grasped in advance and corrected. By changing the energization delay angle as described above, the motor can always be operated near the maximum efficiency.

(5) Since the energization delay angle is changed according to the power consumption of the power supply source, the relationship between the power consumption and the amount of phase shift deviation is grasped in advance and corrected. By changing the energization delay angle as described above, the motor can always be operated near the maximum efficiency.

(6) Since the energization delay angle is changed in accordance with the rotation speed, the current, and the power consumption, the relationship between the rotation speed, the current, and the power consumption and the phase shift amount is grasped in advance. By changing the energization delay angle so as to correct it, the motor can always be operated near the maximum efficiency.

(7) In addition to the operations of (1), (2), (3), (4), (5), and (6), a third signal is output from the integration circuit. Since the phase voltage and the combined voltage of the remaining two phases that are different from the output of each phase are obtained by comparison, it is easy to set the phase shift amount to a more advanced side than 90 °. , The energization timing can be corrected by a software delay .

(8) In addition to the functions (1), (2), (3), (4), (5), (6), and (7), the control unit is constituted by a microcomputer. Therefore, the energization delay angle can be changed by software, so that it is possible to easily cope with the case where different motors are driven, and it is possible to make the configuration inexpensive.

(9) In addition to the operations of (1) and (2) and (3) and (4) and (5) and (6) and (7) and (8), a third signal Since the input is made to the external interrupt terminal of the microcomputer, software processing becomes easy.

(10) The above (1), (2) and (3)
In addition to the effects of (6) and (7) and (8) and (9), the mileage of the electric vehicle can be increased.

[0043]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a control and driving device for a sensorless DC brushless motor according to an embodiment of the present invention.

FIG. 1 shows a sensorless D according to an embodiment of the present invention.
FIG. 2 is a circuit diagram of a control and driving device of the C brushless motor, and FIG. 2 is a voltage waveform diagram of each part at the time of 100% duty. The present invention will be described below with reference to FIG.

The supply of the DC voltage to this circuit is performed from the battery 4 or the commercial power source 5 rectified by the diode bridge 6. Then, the DC voltage is converted by the switching element 1 into an AC voltage of 120 ° conduction of a variable voltage. In this circuit, a variable AC voltage is obtained by the PWM method. However, in the case of the PAM method, only a transistor for DC voltage conversion is added, and other configurations are the same as those of the present circuit. Is fine.

The motor to be controlled and driven comprises a stator winding 2 connected in three phases of U, V and W, and a permanent magnet rotor 7.

First, when starting the motor, since no back electromotive force is detected, the motor is started as a synchronous motor of open loop control . The predetermined reached rotation, from so counter electromotive force is detected charged <br/> content, this counter electromotive force, performs detection of the position of the rotor, the feedback operation in accordance with the position .

Next, the position detecting portion will be described.
The voltage divider 8 divides each terminal voltage including the back electromotive force induced in U, V, and W of the stator winding 2. This is for converting a high-voltage signal into a low-voltage signal that is easy to handle. Note that the solid waveforms of V _U , V _V , and V _W in FIG. 2 show examples of voltage waveforms input to the voltage dividing section.

The AC coupling section 9 is composed of a capacitor, and removes the DC component of the signal from the voltage dividing section 8 and converts the signal into an AC voltage signal.

[0050] Then the integrating circuit integrates the signal from the AC coupling unit 9 times, as indicated by a solid line waveform of V _U1, V _V1, V _W1 of FIG. 2, with respect to the counter electromotive force, slow Than 90 °
It is converted to advanced voltage (first signal). This is return
FIG. 4 explains that the retard angle becomes 90 ° if there is no current.
As we have clarified, the effect is more than 90 °
It has become.

The comparing circuit 11 is provided with the integrating circuit 10
And a signal obtained by synthesizing a signal different from that phase (second signal: V _U2 , V _V2 , V _{W2 in} FIG. 2),
It is converted into a digital signal (third signal) shown by the solid waveforms of V _U3 , V _V3 , V _W3 in FIG.

Here, the feature of the comparison circuit 11 is that the third signal is further advanced with respect to the first signal and the back electromotive force by setting the resistance.

As a result, the third signal is as shown in FIG.
Against Ku counter electromotive force, it has a delayed signal of 50 °. And the meaning of this 50 ° delay is 9
For 0 ° delay is that has a (40 °) signal advanced to the charge amount.

The third signal from the comparison circuit 11 is input to an external interrupt terminal of the control unit 12 (microcomputer), and the control unit 12 uses the change in the state of this signal as a trigger to change the load or rotation. An energization delay angle determined according to the number is provided, and the energization pattern is switched.

[0055] For example, from the load and rotation speed detected, actual
If it is determined that the deviation of the first signal from the previously set phase shift amount is zero, an energization delay angle (40 ° -0 °) of 40 ° is provided, Switch the energization pattern. Here, the above-mentioned “preset of the actual first signal,
Deviation from the shifted phase shift amount ”is hereinafter referred to as“ phase deviation ”.
Call it.

When it is determined that the phase shift is advancing by 10 ° from the detected load and rotation speed, a 30 ° conduction delay angle (40 ° -10 °) is provided to switch the conduction pattern.

If it is determined that the phase shift is a delay of 10 ° based on the detected load and the number of rotations, a conduction delay angle (40 ° + 10 °) of 50 ° is provided to switch the conduction pattern.

Here, the third signal is transmitted to the controller 12
The input to the external interrupt terminal of the (microcomputer) is for setting the energization delay angle more accurately by giving priority to this energization delay angle process over other processes.

By controlling in this way, even if a phase shift occurs due to the load or the number of rotations, the motor can always be operated near the maximum efficiency by adjusting with the power supply delay angle.

FIG. 7 shows experimental data obtained by measuring the relationship between the rotational speed, the motor current and the phase shift. The higher the rotational speed is, the more the delay is shifted, and the higher the current (load) is, the more the shift is made. I understand. It should be noted that the same relationship holds when the current is a DC load current or an AC power supply current.

FIG. 8 shows experimental data obtained by measuring the relationship between the rotational speed and the power consumption and the phase shift. The higher the rotational speed, the more the shift to the delay side, and the higher the power consumption (load), the more the shift to the leading side. You can see that

FIGS. 9A and 9B are schematic flowcharts for determining the energization delay angle. More specifically, data obtained from the characteristics shown in FIGS. 7 and 8 is used as a data table. It is stored in the ROM of the microcomputer, and the energization delay angle is determined based on it.

As another method, there is a method in which an arithmetic expression is derived by a theoretical analysis or an experiment and determined based on the expression.

FIG. 10 is a graph comparing the motor efficiencies of the present invention and the conventional system. The graphs are equivalent at some points, but the efficiency of the present invention is better in all other areas. I understand.

[0065]

As described above, the sensorless DC according to the present invention is
The control driving device of the brushless motor detects (1) the back electromotive force induced in each phase of the three-phase connected stator winding when the permanent magnet rotor is rotated by receiving the supply of the DC voltage. By detecting the angular position of the rotor, the control drive device of the sensorless DC brushless motor that switches the energization pattern to each phase of the stator winding in accordance with the angular position of the rotor has shifted the phase of the back electromotive force. Outputting a third digitized signal obtained by comparing one signal and a second signal near the zero potential of the AC component of the first signal; and With respect to the back electromotive force of the signal, a position detection circuit in which the absolute value of the phase shift is set to a more advanced side than 90 ° or 30 °, and a change in a third signal output from the position detection circuit as a trigger, Solid A control unit that switches an energization pattern to each phase of the child winding, wherein the control unit delays until the rotor advances by a predetermined angle after the third signal changes, thereby changing the energization pattern. Since the switching and the power supply delay angle are provided, the power supply timing to the stator winding can be set at an arbitrary timing, whereby the motor can always be operated near the maximum efficiency.

(2) In addition to the configuration of the means (1) for solving the above-mentioned problem, a current detecting means for detecting a current flowing through the stator winding or a DC current supplied from a DC voltage is provided. Since a control unit for changing the energization delay angle in accordance with the current is provided, in addition to the effect of the above (1), it is possible to prevent the motor efficiency from actually deteriorating due to the load fluctuation, and to always maintain the The motor can be operated nearby.

(3) In addition to the configuration of the means (1) for solving the above-mentioned problem, a voltage detecting means for detecting a DC voltage and a current detecting means for detecting a DC current supplied from the DC voltage are provided. And a control unit for detecting power consumption from the voltage and the current and changing the power supply delay angle in accordance with the power consumption is provided. Can prevent the motor efficiency from deteriorating due to the fluctuation of the motor, and can always operate the motor near the maximum efficiency.

(4) In addition to the configuration of means (1) for solving the above-mentioned problem, the DC voltage is a DC voltage obtained by rectifying an AC voltage, and the AC current supplied from the AC voltage is detected. And a control section for changing the conduction delay angle in accordance with the current is provided. In addition to the effect of (1), the motor efficiency is actually reduced by the load fluctuation. Thus, the motor can always be operated near the maximum efficiency.

(5) In addition to the configuration of the means (1) for solving the above-mentioned problem, the DC voltage is a DC voltage obtained by rectifying an AC voltage, and a voltage detecting means for detecting the AC voltage; A current detection unit for detecting an alternating current supplied from an alternating voltage is provided, and a control unit that detects power consumption from the voltage and the current and changes a conduction delay angle in accordance with the power consumption is provided. Therefore, in addition to the effect of the above (1), it is possible to prevent the motor efficiency from actually deteriorating due to the load fluctuation, and to always operate the motor near the maximum efficiency.

(6) In addition to the configuration of means (1) and (2) and (3) and (4) and (5) for solving the above-mentioned problem, a third output from the position detection circuit is provided. Since the control unit for detecting the rotation speed of the rotor from the signal cycle or frequency and changing the energization delay angle according to the rotation speed is provided, in addition to the effect of (1), the load is actually In addition, it is possible to prevent the motor efficiency from deteriorating due to fluctuations in the rotational speed and the number of revolutions, and to always operate the motor near the maximum efficiency.

(7) Means for solving the above-mentioned problem (1) and (2) and (3) and (4) and (5) and (6) is a position detecting circuit, which is a negative potential of DC voltage. A voltage divider that converts the voltage level of the back electromotive force as an input with the back electromotive force of each phase induced in the stator winding based on the reference, and an AC coupling unit that removes the DC component of the back electromotive force A back electromotive force detection circuit having: a voltage of each phase output from the back electromotive force detection circuit, an integration circuit that integrates and performs a phase shift, and a voltage of each phase output from the integration circuit. , And a comparison circuit for comparing each output with the remaining two-phase combined voltages different from each other, so that the above (1), (2), (3), (4), (5), and ( In addition to the effect of 6), the amount of phase shift is
It is easier to set the angle to the leading side than 90 ° or 30 ° , and it is possible to delay the energization timing from the input of the third signal and correct it to the optimum point.

(8) Means for Solving the Problems (1) and (2) and (3) and (4) and (5) and (6) and (7) are constituted by a microcomputer. (1) and (2) and (3)
In addition to the effects of (4), (5), (6), and (7), the energization delay angle can be changed by software, which makes it easy to drive different motors. And an inexpensive configuration.

(9) The third signal output from the position detection circuit of the means (8) for solving the above problem is
Since the signal is input to the external interrupt terminal of the microcomputer, software processing becomes easy in addition to the effect (8).

(10) Means for solving the above-mentioned problem (1) and (2) and (3) and (6) and (7) and (8) and (9) Is supplied from a battery mounted on the electric vehicle, and the electric compressor motor for air-conditioning the electric vehicle is controlled and driven. Therefore, the above (1), (2), (3) and (3) In addition to the effects of 6) and (7), and (8) and (9), the mileage of the electric vehicle can be extended.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of one embodiment of the present invention.

FIG. 2 is a diagram showing waveforms and energization timings of respective parts according to an embodiment of the present invention.

FIG. 3 is a conventional basic circuit block diagram.

FIG. 4 is a diagram showing waveforms and energization timings of conventional parts.

FIG. 5A shows an input / output response waveform (high frequency ) of an integrating circuit.
H) (B) output response waveform of the integrating circuit (at low frequency)

FIG. 6 is a phase terminal voltage waveform diagram at the time of phase shift.

FIG. 7 is a characteristic diagram showing a relationship between a rotational speed, a motor current, and a phase shift.

FIG. 8 is a characteristic diagram showing a relationship between a rotation speed, power consumption, and a phase shift.

FIG. 9A is a control flowchart in the control unit of the present invention, and FIG.

FIG. 10 is a motor efficiency comparison diagram of the present invention and a conventional system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Switching element 2 Stator winding 3 Diode (for surge absorption) 4 Battery 5 Commercial power supply 6 Diode bridge 7 Permanent magnet rotor 8 Voltage divider 9 AC coupling part 10 Integration circuit 11 Comparison circuit 12 Control part (microcomputer) 13 Current sensor 14 voltage sensor 15 counter electromotive force detecting circuit _{V U,} V V, V _W phases terminal voltage V _U1, V _V1, V _W1 first signal V _U2, V _V2, V _W2 second signal V _U3, V _V3, V _W3 third signal a _D energization delay angle a _S phase shift angle _{U H, V H, W H} , U L, V L, W L phase current supply transistor E DC voltage value

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02P 6/02

Claims (11)

(57) [Claims] An angular position of a rotor is detected by detecting a back electromotive force induced in each phase of a three-phase connected stator winding, and accordingly, each of the stator windings is detected. A control and driving device for a sensorless DC brushless motor for switching an energizing pattern to a phase, wherein in each phase, a first signal in which the phase of the back electromotive force is shifted and the first signal in the other two phases have different resistance values. By partial pressure
Obtained by comparing the second signal formed, the back EMF absolute value phase shift also advanced side than 90 ° relative to the phase of the
Amount, a position detection circuit for outputting a third signal digitized, as a trigger a change in the third signal, and a control unit for switching the energization pattern to the respective phases of the stator windings, A control and driving device for a sensorless DC brushless motor, comprising: a control unit for switching the power supply pattern by providing a power supply delay angle that delays until the rotor advances by a predetermined angle after the third signal changes. And a current detecting means for detecting a current flowing through the stator winding or a DC current supplied from a DC voltage, wherein a current-carrying delay angle is changed in accordance with the detected current value. The control and driving device for a sensorless DC brushless motor according to claim 1. 3. A voltage detecting means for detecting a DC voltage, and a current detecting means for detecting a DC current supplied from the DC voltage, wherein a power consumption value obtained from the detected voltage value and the current value is provided. 2. The control and driving device for a sensorless DC brushless motor according to claim 1, wherein the energization delay angle is changed accordingly. 4. The method according to claim 1, wherein the DC voltage is a DC voltage obtained by rectifying an AC voltage, and comprises a current detecting means for detecting an AC current supplied from the AC voltage. The control and driving device for a sensorless DC brushless motor according to claim 1, wherein the angle is changed. 5. The apparatus according to claim 1, wherein the DC voltage is a DC voltage obtained by rectifying an AC voltage, and comprises voltage detecting means for detecting the AC voltage; and current detecting means for detecting an AC current supplied from the AC voltage. 2. The control and driving device for a sensorless DC brushless motor according to claim 1, wherein the energization delay angle is changed according to a value of power consumption obtained from the detected voltage value and current value. 6. The power supply delay angle according to claim 1, wherein the energization delay angle is changed according to the rotation speed of the rotor obtained from the cycle or frequency of the third signal. Control drive device for sensorless DC brushless motor. 7. A position detecting circuit comprising: a voltage divider for converting a voltage level of a back electromotive force by inputting a back electromotive force of each phase induced in a stator winding with reference to a negative potential of a DC voltage as an input; A back electromotive force detection circuit having a unit and an AC coupling unit for removing a DC component of the back electromotive force, and an integration for integrating and phase-shifting the voltage of each phase output from the back electromotive force detection circuit. 7. A circuit according to claim 1, comprising: a circuit; and, in each phase, a comparison circuit that compares a voltage output from the integration circuit with a composite voltage of the other two-phase voltages output from the integration circuit. A control and driving device for a sensorless DC brushless motor according to any one of the preceding claims. 8. The control and driving device for a sensorless DC brushless motor according to claim 1, wherein the control unit is constituted by a microcomputer. 9. The control and driving device for a sensorless DC brushless motor according to claim 8, wherein the third signal is input to an external interrupt terminal of the microcomputer. 10. The control and driving device for a sensorless DC brushless motor according to claim 1, wherein a DC voltage is supplied from a battery. 11. The control and driving device for a sensorless DC brushless motor according to claim 1, wherein the device drives and controls an electric compressor motor for performing air conditioning for an automobile.