JP3856020B2 - Brushless motor control device and equipment using this motor - Google Patents

Description

  The present invention relates to a control device that controls the rotational speed of a brushless motor to a desired rotational speed, and an air conditioner and compressor that control the brushless motor for driving a compressor and a blower by using the control device to perform indoor air conditioning. The present invention relates to a refrigerator that performs refrigeration by controlling a brushless motor for driving a fan and a blower, and a washing machine that performs laundry washing by controlling a brushless motor for driving a stirring blade and a dewatering tank.

  Brushless motors combining permanent magnet rotors and stator windings are used in air conditioners, refrigerators, washing machines, etc. for ease of maintenance.

  The drive control of this brushless motor needs to be performed by closely relating the magnetic pole position of the rotor and the position of the stator winding to be energized. For detecting the magnetic pole position of the rotor, a rotor position detection sensor such as a Hall element is not used, and the rotor is utilized by utilizing a counter electromotive voltage induced in the stator winding by interaction with the rotor magnetic pole. A sensorless position detection method for detecting the magnetic pole position is employed.

  As a brushless motor driving device employing such a rotor position detection method, for example, there is a brushless motor driving device described in Japanese Patent Laid-Open No. 7-147793. This brushless motor driving device supplies a DC voltage output from a DC power source to a stator winding of a brushless motor via an inverter circuit. The terminal voltage detector divides the terminal voltage of the stator winding of the brushless motor, takes it out as a detection voltage, and inputs this to the comparison circuit. The comparison circuit compares the detected voltage with a reference voltage and outputs a phase signal.

  The control device latches by the latch timing signal generation circuit so that the latch operation is performed after the timing when the PWM signal PS changes from on to off based on the PWM signal PS from the pulse width modulation (PWM) signal generation circuit. The timing signal LS is generated, and even when vibration occurs in the terminal voltage of the stator winding, the phase signal from the comparison circuit is latched by the latch circuit without being affected by the vibration and the position detection signal is obtained. Is.

JP-A-7-147793

  In such a conventional brushless motor driving apparatus, the output signal of the latch circuit is delayed by the time tdD from the phase signal output from the comparison circuit, and the detected position of the rotor magnetic pole obtained based on this is the rotation This is a significant deviation from the actual position of the child pole.

  As described above, when the detection timing of the position detection signal is greatly deviated, the commutation (energization) phase of the stator winding current of the brushless motor is delayed, the current rise is delayed, and immediately before the switching of the winding current. As the current jumps up, the current capacity of the circuit element needs to be increased due to the decrease in efficiency and the burden on the drive circuit due to the current jump, leading to an increase in cost, or the output signal of the comparison circuit due to disturbance noise at the latch timing If the noise is superimposed on the motor, the phase signal that is greatly deviated from the original position detection signal is latched, and the brushless motor cannot be driven normally and vibrates or stops. .

  Further, in such a conventional brushless motor driving device, since the latch operation is performed after the timing when the PWM signal PS changes from on to off, when the conduction ratio in PWM control is 100%, There is a problem that the gate signal of the latch circuit cannot be defined, or that the gate signal at 100% conduction rate such as so-called PAM control cannot be defined.

  One object of the present invention is to provide a control device for a brushless motor, which has high magnetic pole position detection accuracy of a rotor and can perform accurate control with respect to a brushless motor.

  Another object of the present invention is to reduce position detection errors due to noise.

  It is still another object of the present invention to provide a brushless motor control device that can reduce energization malfunction due to noise.

  Still another object of the present invention is to provide a control device for a brushless motor capable of extending the control range.

  Still another object of the present invention is to provide a control device that can control the operation of a brushless motor with an emphasis on efficiency or control the operation with an emphasis on high speed.

  Still another object of the present invention is to provide a control device for a brushless motor having a wide control range.

  Still another object of the present invention is to provide a control device for a brushless motor capable of performing good control without stopping the brushless motor even when the period during which the circulating current flows after switching of energization is very long. There is.

  Still another object of the present invention is to provide an apparatus using a brushless motor controlled as described above as a power source, particularly an air conditioner, a refrigerator, and a washing machine.

  One feature of the present invention is a brushless motor control device that detects the position of a magnetic pole of a rotor based on a terminal voltage of a stator winding of each phase and controls energization to the stator winding. The on / off period of the PWM signal is extracted based on the comparison result information signal obtained by comparing the detection voltage corresponding to the terminal voltage with the reference voltage.

  Another feature of the present invention is that the comparison result information signal is directly output as a phase signal during the on period of the PWM signal extracted based on the terminal voltage of the stator winding, and the comparison immediately before being turned off during the off period. The result information signal is held and output as a phase signal.

  Another feature of the present invention resides in that the position of the rotor is detected based on the comparison result information signal pattern of the terminal voltages of the stator windings of a plurality of phases.

  Another feature of the present invention resides in that the energization pattern to the stator winding is determined based on the pattern of the comparison result information signal of the terminal voltages of the stator windings of a plurality of phases.

  Another feature of the present invention is to detect a period during which a circulating current flows after switching of energization based on a comparison result information signal pattern of terminal voltages of a plurality of stator windings.

  Another feature of the present invention resides in that a process of updating a phase signal pattern to be collated for position detection is performed after the circulating current after switching of energization disappears.

  Another feature of the present invention resides in that a process of updating a phase signal pattern to be collated for position detection is performed when a predetermined time has elapsed after switching of energization.

  Another feature of the present invention is that the rotor position is detected based on the pattern of the comparison result information signal, and the energization phase is switched according to the energization phase information stored in the memory or the phase control command from the outside.

  Another feature of the present invention resides in that phase control with emphasis on operating efficiency is performed in the PWM control region, and control for advancing the energization phase is performed in the high-speed rotation emphasis control region.

  Still another feature of the present invention resides in an air conditioner, a refrigerator, or a washing machine that uses a brushless motor controlled by the control device as described above as a power source.

  Still another feature of the present invention is a brushless motor system having a brushless motor and a controller for controlling the brushless motor, the controller based on the voltage of the stator winding of the brushless motor. The purpose is to detect the rotor position.

  According to the present invention, the magnetic pole position detection accuracy of the rotor is high and accurate control can be performed on the brushless motor.

  Also, position detection errors and power-on malfunctions due to noise can be reduced, and the control range can be expanded.

  In addition, since the operation of the brushless motor can be controlled with the efficiency-oriented characteristic or the high speed-oriented characteristic, the brushless motor can be controlled over a wide range.

  A high-performance air conditioner, refrigerator, and washing machine can be realized by using the brushless motor controlled by the control device described above as a power source.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a brushless motor control device according to the present invention and an apparatus using a brushless motor driven and controlled by the control device will be described below with reference to FIGS.

  FIG. 1 is a block diagram showing an embodiment of a brushless motor driving apparatus according to the present invention. The brushless motor driving device includes a rectifying circuit 2 that rectifies an AC voltage from an AC power source 1, a smoothing circuit 3 that smoothes the rectified output voltage to a DC voltage, and converts the DC voltage into an AC voltage having an arbitrary pulse width. An inverter circuit 4 that rotates the brushless motor 5 by converting it and supplying it to the stator winding of the brushless motor 5, and a control circuit (one-chip microcomputer) that performs control processing of the brushless motor 5 according to the speed command signal SV Alternatively, the hybrid IC) 6, the driver 7 that drives the inverter circuit 4 according to the control circuit 6, and the terminal voltage (= counterelectromotive force) of each phase of the stator winding of the brushless motor 5 obtained from the terminal voltage detector 8. The control circuit 6 generates a phase signal 9a which is positional information of the magnetic poles of the rotor of the brushless motor 5 based on the detection voltage 8a corresponding to And a phase signal generation circuit 9 supplies.

  The phase signal generation circuit 9 basically outputs the comparison result information signal 10b from the comparison circuit 10 for the detection voltage 8a corresponding to the terminal voltage of each phase of the brushless motor 5 when the PWM signal is on. When the PWM signal is off, it is a circuit means for holding the comparison result information signal 10b immediately before the PWM signal is turned off and outputting it as a phase signal 9a. The phase signal generation circuit 9 compares the detection voltage 8a corresponding to the terminal voltage of each phase of the stator winding of the brushless motor 5 with a reference voltage, and each output from the comparison circuit 10. A delay circuit 11 for delaying the phase comparison result information signal 10b, a selection holding circuit 12 for outputting a phase signal 9a generated based on the output signal 11a from the delay circuit 11 to the control circuit 6, and the selection holding circuit 12 includes a gate signal generation circuit 13 that generates a gate signal 13a for controlling the operation characteristics of 12 based on the comparison result information signal 10a output from the comparison circuit 10.

  The comparison circuit 10 is a circuit that compares the detection voltage 8a corresponding to the terminal voltage of each phase of the stator winding of the brushless motor 5 with a reference voltage, and outputs comparison result information signals 10a and 10b for each phase. . Here, the reference voltage used for the comparison is a neutral point voltage of the stator winding of the brushless motor 5 or a voltage that is ½ of the DC voltage output from the smoothing circuit 3.

The gate signal generation circuit 13 extracts an on period or an off period of the PWM control by logical processing based on the comparison result information signal 10a output from the comparison circuit 10, and the selection holding circuit 12 detects the time at that time. It has a function of creating and outputting a gate signal 13a for selecting whether to output a phase signal reflecting the voltage 8a or to hold a signal level before the PWM signal is turned off and to output it as a phase signal. . When the voltage level of the detection voltage 8a is at a level that can be processed by a general logic circuit, a gate signal can be created directly from the detection voltage 8a.

  The delay circuit 11 is a functional unit that delays the comparison result information signal 10b of each phase output from the comparison circuit 10 so as to match the operation timing when the signal is selected and held by the selection holding circuit 12. . Specifically, the delay circuit 11 is for adjusting the timing of the signal 11a input to the selection holding circuit 12 and the operation of the selection holding circuit 12 (gate signal 13a). The comparison result information signal 10b and the gate signal 13a are matched in consideration of the circuit constants of the signal generation circuit 13, and can be omitted.

  The selection holding circuit 12 outputs the output signal 11a from the delay circuit 11 as the phase signal 9a as it is according to the gate signal 13a given from the gate signal generation circuit 13, or the gate signal 13a This is a functional means for selecting whether the signal level before the change is held and output as the phase signal 9a.

  FIG. 2 is a block diagram illustrating a specific configuration of the gate signal generation circuit 13. The illustrated gate signal generation circuit 13 is configured by a combination of logic elements, inputs the comparison result information signal 10a of each phase as Vu, Vv, Vw, and outputs the logical processing result (output X) of the logical expression (Equation 1). The gate signal 13a is output. Therefore, any logic circuit satisfying (Equation 1) can be used in the same manner even in other configurations.

  FIG. 3 shows signal waveforms in the control circuit 6 and the phase signal generation circuit 9. In FIG. 3, (a) is a PWM signal output from the control circuit 6. On the other hand, (b) shows the detected voltage waveform of the terminal voltage of the stator winding of the brushless motor 5 reflecting the delay of tdON at the rise and tdOFF at the fall due to the influence of the driver 7 and the inverter circuit 4. . (C) is comparison result information signals 10a and 10b output from the comparison circuit 10, and (d) is a gate signal 13a created by the gate signal creation circuit 13 based on the comparison result information signal 10a.

  As shown in (e), the selection holding circuit 12 reflects the output signal 11a of the delay circuit 11 when the signal 13a is at a high level according to the gate signal 13a, and the signal immediately before the low level when the signal 13a is at a low level. A phase signal 9a having a waveform having a level is output.

FIG. 4 shows an example of internal processing of the control circuit 6 for the phase signal 9a. Process 41 is a main process of motor control including speed control of a brushless motor. The process 42 is a signal process related to the rotor position detection, the process 43 is a drive process that determines the switching operation of the inverter circuit 4 according to the rotor position determined by the process 42, and the process 44 is based on the position detection process. The preparation flag clear process related to the drive process, process 45, is a match flag clear process for determining whether the phase signal pattern matches twice. Here, the drive process of process 43 is a process in which energization can be switched after a lapse of a predetermined time adjusted by phase correction.

  The process 42 is a process of periodically reading the phase signal 9a and detecting (determining) the rotor position based on the phase signal 9a. The detection of the rotor position is performed by checking the pattern of the phase signal 9a with a predetermined signal pattern because the phase signal 9a exhibits a predetermined signal pattern depending on the position of the rotor.

  The process 42a performs signal processing related to rotor position detection during an electrical angle of 30 degrees, during an electrical angle of 60 degrees, during an electrical angle of 120 degrees, during an electrical angle of 360 degrees, during a mechanical angle of 360 degrees, etc. It is a count process for managing how many times it has been performed. In addition, it is a count process that can manage the passage of a predetermined time.

  The process 42b is a process for reading the phase signal 9a of each phase. At this time, in order to know the timing at which the phase signal 9a is read, it is effective to confirm the operation of the control device by outputting a signal of HI level or LOW level from the control circuit 6.

  The process 42c is a process for determining whether or not a predetermined time has elapsed after the medium power switch, and the determination is made from an internal timer or a count value obtained by the process 42a or the like.

  The process 42d is a branch process for determining whether or not a predetermined signal pattern necessary for the next energization control process is set.

  The process 42e is a process of updating / setting a predetermined signal pattern for the next energization control process when it is determined in the process 42d that a predetermined signal pattern necessary for the next energization process is not set. is there. The process 42e is a process for setting a preparation flag indicating that a predetermined signal pattern has been updated, and the process 42f is a process for clearing a flag used when determining whether or not the positioned signal pattern is the first time. It is processing.

  The process 42h collates the pattern of each phase signal 9a read in the process 42b with a predetermined signal pattern determined by the rotor position.

  The process 42i proceeds to the process 42k when the signal patterns match, and jumps to the process 42j when the signal patterns do not match.

  The process 42j performs a process of clearing a flag used when determining whether or not the matched signal pattern is matched twice.

  The process 42k is a branch process for determining whether or not the matched signals are matched twice. The process 421 is a process for turning on the match flag when the match flag is off and the signal patterns match. The process 42m is a branch process for determining whether or not a predetermined signal pattern necessary for the next energization control process is set.

  The process 42n is a process of updating / setting a predetermined signal pattern for the next energization control process when it is determined in the process 42m that a predetermined signal pattern necessary for the next energization process is not set. is there. The process 42o is a process for setting a preparation flag indicating that a predetermined signal pattern has been updated, and the process 42p is a clearing of a flag used when determining whether or not the matched signal pattern is the first time. It is processing. That is, when a predetermined signal pattern is updated in the process 42e or 42n and the signal pattern of the phase signal 9a read in the process 42b matches twice, an appropriate energization pattern is determined for this rotational position. Then, the drive process 43 is performed.

  Here, since the processes 42d to 42g and the processes 42n to 42p are equivalent, the increase in the program is minimized by making a subroutine, and at the same time, the brushless motor can be satisfactorily performed even when the circulation period after the energization switching is long. Can be controlled.

  FIG. 5 shows the detection 8a of the terminal voltage of each phase (U, V, W phase) of the stator winding of the brushless motor 5 when the conduction rate is less than 100% in the PWM control, the PWM signal, and the comparison circuit. The comparison result information signal of each phase to be output, the information signal pattern when PWM is read by the control circuit 6, and the position detection information recognized inside the control circuit are shown.

When the control process using the algorithm shown in FIG. 4 is performed with reference to FIG. 5, even if a phase signal equivalent to t2 and t4 appears immediately after switching of the energization pattern as shown by t1 and t3 in FIG. The determination can be prevented, and the phase signal can be obtained satisfactorily and the energization switching can be performed satisfactorily without being affected by the circulating current that flows immediately after the energization pattern switching.

  Further, when the signal vibrates in the vicinity of the reference point as shown in FIG. 3B after the signal pattern is updated in the processing 42e and the processing 42n described with reference to FIG. 4, the processing shown in FIG. As shown in FIG. 3, when the vibration signal is output and the process 41 shifts to the periodic process 42, the process 42 is performed at the timing shown in FIG. 3D, and the process 42b is performed at the timing (e). In step 42h, the signal pattern is verified, and in step 42i, the process proceeds to step 42k due to pattern matching. At this time, during the current energization period, the pattern match is the first time and the match flag is off, so the process branches from the process 42k to the process 42l. Thereafter, the process 42b is performed again at the timing of (g) td in FIG. 3. After the process 42h is performed, the process 42i branches to the process 42j because the signal pattern does not match, and the match flag is cleared. Return to process 41.

  Further, when moving from the process 41 to the periodic process 42, the process 42b is performed at the timing tc in FIG. 3C, and similarly to the above, the process 42l is performed, and the td in FIG. Processing 42b to processing 42k are executed at the timing, and since the coincidence flag is ON, the processing proceeds to processing 43 through processing 42m, and drive processing suitable for the rotor position is performed.

  By using the phase signal generation circuit 9 and the position detection algorithm, it is possible to detect the rotor position satisfactorily even when pulsed noise occurs and to perform good motor control. Further, in this embodiment, the condition that the pattern matching of the phase signal 9a is advanced to the drive process is a condition that is advanced to the drive process. Even if it is omitted by suppressing the appearing noise and vibration, it is effective.

FIG. 6 shows the detection voltage 8a of the terminal voltage of the stator winding of the brushless motor 5 when the duty ratio is 100% or the pulse amplitude modulation (PAM) control in the PWM control, and is output from the comparison circuit 10. The comparison result information signals 10a and 10b, the gate signal 13a output from the gate signal generation circuit 13, and the phase signal 9a output from the selection holding circuit 12 are shown.

When this phase signal generation circuit 9 is used, when the PWM signal is on, the comparison result information signal 10b is reflected as it is in the phase signal 9a. The same phase signal 9a can be obtained regardless of whether or not the chopping operation is being performed, and good motor control is possible even in PAM control.

In this embodiment, even in the configuration using the output voltage variable type rectifier circuit 2, the reference voltage of the comparison circuit 10 varies according to the output voltage at that time, so that PWM control and PAM control or PWM / In any PAM switching control, an equivalent phase signal can be obtained, and good motor control can be realized.

  FIG. 7 shows the terminals of the stator windings of the brushless motor 5 when the duty ratio is 100% in the PWM control or in the PAM control, the period during which the circulating current flows after switching the energization is longer than that in FIG. A voltage detection voltage 8a, a comparison result information signal output from the comparison circuit, and one phase of position detection information inside the control circuit are shown.

  Since the process 42e is provided for determining whether a predetermined time has elapsed after the switching of energization, even if the information signal does not change in the vicinity of the reference voltage as shown in FIG. Therefore, good motor control is possible without stopping the motor.

  When such a phase signal generation circuit 9 is used, the PWM signal on-period and off-period are extracted from the voltage (terminal voltage) actually applied to the stator winding of the brushless motor 5. This eliminates the need for external timing adjustment and correction operations, and can generate a phase signal for performing excellent rotational position detection processing even when the circuit constants for determining the delay time change. Incidentally, since a delay time due to operation delay occurs between the PWM signal generated in the control circuit 6 and the voltage actually applied to the stator winding of the brushless motor 5, the PWM signal is converted into the PWM signal in the control circuit 6. Accordingly, if it is attempted to accurately detect the rotor position from the motor terminal voltage, timing adjustment between the two is necessary.

  The control circuit 6 detects (determines) the rotor position based on the phase signal pattern corresponding to the terminal voltage (detected voltage) of the stator winding of each phase of the stator winding at a certain time (timing). As a result, erroneous detection due to noise can be reduced.

  In addition, since the control circuit 6 can determine the next energization pattern from the rotor position and the current energization pattern to the stator winding, it is possible to reduce malfunction due to noise.

  In the rotational position detection by edge interrupt processing as in the conventional control device, it is necessary to provide a phase signal reading prohibition section in order to avoid a malfunction due to a spike voltage that occurs immediately after commutation. Since such a phase signal reading prohibition section is unnecessary, the time during which the circulating current flows (timing at which the circulating current disappears) can be estimated by measuring the spike voltage period, and this can be used for phase control. A wide range of control can be realized by utilizing it.

  As shown in FIG. 8, the operation efficiency of the brushless motor changes depending on the energization phase with respect to the counter electromotive force, and thus the energization phase is a very important factor. Therefore, the brushless motor can be operated with high efficiency by controlling the energization phase using information stored in the RAM or ROM in advance so that the maximum efficiency is obtained when the motor is started.

  Further, if the energization phase can be controlled from the outside, the brushless motor can be operated at the energization phase matched to the motor on the user side. As the control terminal for external control, an A / D conversion terminal, a communication terminal, an input port, or the like of the control circuit 6 can be used.

  In brushless motor speed control, PWM control, which performs speed control by pulse width control of the terminal voltage supplied to the stator winding, will rotate beyond that when the conduction ratio reaches the maximum value (100%). It is not possible to perform control to increase Further, in PAM control in which speed control is performed by controlling the height of the terminal voltage supplied to the stator winding, when the terminal voltage reaches the maximum value, control for further increasing the rotation speed may be performed. Can not. However, as shown in FIG. 9, the rotational speed can be changed by changing the energization phase while maintaining the terminal voltage supplied to the stator winding at the same value. And control of this energization phase is realizable using a phase signal.

  Therefore, the rotation speed of the motor can be controlled over a wider range by performing energization phase control in addition to PWM control and / or PAM control of the stator winding current of the brushless motor. For example, when the conduction ratio does not reach the maximum value in the PWM control or the supply voltage does not reach the maximum value in the PAM control, the control is performed at the energization phase so that the motor efficiency is maximized. After the flow rate or supply voltage reaches the maximum value, control is performed to advance the energization phase beyond the maximum efficiency point. It can be advanced to achieve high speed operation control characteristics.

  Such a control device is configured as a hybrid IC in which the control circuit 6 and the phase signal generation circuit 9 are integrated or an intelligent power module in which the inverter circuit 4, the control circuit 6, the driver 7, and the phase signal generation circuit 9 are integrated. The number of parts can be reduced and the control device can be easily handled.

  Since the air conditioning output of the heat pump type air conditioner changes depending on the rotation speed of the compressor, as described above, a brushless motor that is controlled in energization phase in addition to PWM control and / or PAM control is used as the compressor and / or By using it as a drive source for a blower, an air conditioner with high air conditioning capability can be realized. In addition, an energy-saving air conditioner can be obtained by performing operation control with emphasis on efficiency in a normal operation region.

  Similarly, a brushless motor controlled using this control device can be used as a drive source for driving a compressor and / or a blower of a refrigerator, thereby realizing a refrigerator having an excellent refrigerating capacity.

  Furthermore, when a washing machine that rotates a stirring blade and a dewatering tub using a brushless motor controlled by this control device as a power source is configured, a washing machine having excellent controllability can be obtained. In particular, it is effective in realizing energy saving and high-speed dehydration.

  In addition, when the phase signal generation circuit according to the present invention is used, it is not necessary to use an electrolytic capacitor having a large capacity, and in addition, the control circuit has a function of holding the signal level. Can be used to detect the rotor position of the brushless motor, and by integrating with the inverter circuit and driver circuit, a small and inexpensive inverter control circuit can be realized. By configuring the refrigerator and the washing machine, it is possible to realize a small, inexpensive and air-conditioning machine, a refrigerator, and a washing machine that are excellent in controllability.

It is a block diagram which shows one Embodiment of the brushless motor drive device which becomes this invention. FIG. 2 is a block diagram of a gate signal generation circuit in the brushless motor driving apparatus according to the present invention shown in FIG. 1. It is each signal waveform in connection with the position detection circuit in the brushless motor drive device according to the present invention shown in FIG. It is a process flowchart which the control circuit in the brushless motor drive device which becomes this invention shown in FIG. 1 implements. FIG. 4 is a signal waveform when the PWM control conduction rate of the position detection circuit in the brushless motor driving apparatus according to the present invention shown in FIG. 1 is less than 100%. FIG. 3 is a PWM control duty ratio 100% related to the position detection circuit in the brushless motor driving apparatus according to the present invention shown in FIG. 1 and signal waveforms during PAM control. The figure which shows each signal waveform when the period when the circulating current after energization switching flows is long. It is a driving efficiency characteristic figure of a brushless motor. It is a speed characteristic figure of a brushless motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... AC power source, 2 ... Rectifier circuit, 3 ... Smoothing circuit, 4 ... Inverter circuit, 5 ... Brushless motor, 6 ... Control circuit, 7 ... Driver, 8 ... Terminal voltage detector, 8a ... Detection voltage, 9 ... Phase signal Generation circuit, 9a ... phase signal, 10 ... comparison circuit, 10a, 10b ... comparison result information signal,
DESCRIPTION OF SYMBOLS 11 ... Delay circuit, 12 ... Selection holding circuit, 13 ... Gate signal preparation circuit, 13a ... Gate signal.

Claims (13)

A voltage detection means for generating a detection voltage corresponding to a terminal voltage of a plurality of stator windings of a brushless motor, a reference voltage generation means for generating a reference voltage, and a comparison result comparing the detection voltage and the reference voltage A comparison means for outputting an information signal; a control means for detecting the rotational position of the rotor of the brushless motor based on the comparison result information signal; and generating an energization signal for the stator winding in accordance with the rotational position; In a position sensorless control device for a brushless motor comprising output means for energizing the stator winding based on the energization signal,
A position sensorless control apparatus for a brushless motor, characterized in that the control means creates a gate signal indicating a timing at which the inverter circuit is actually turned on or off based on the comparison result signal. In claim 1,
A position sensorless control device for a brushless motor, wherein the control means creates a phase signal from the comparison result information signal and the gate signal. In claim 1,
The position sensorless control apparatus for a brushless motor, wherein the control means creates the phase signal from a signal obtained by delaying the comparison result information signal and the gate signal. In claim 1,
The control means outputs the comparison result information signal as a phase signal as it is when the gate signal is on, and outputs the comparison result information signal immediately before it is turned off as a phase signal when the gate signal is off. A position sensorless control device for a brushless motor. In claim 1,
The control means outputs a signal obtained by delaying the comparison result information signal as a phase signal when the gate signal is on, and delays the comparison result information signal immediately before turning off when the gate signal is off. A position sensorless control device for a brushless motor, wherein the signal is output as a phase signal. In any of claims 2 to 5,
A position sensorless control device for a brushless motor, wherein the control means detects a rotational position of a rotor of the motor from the phase signal. In any one of Claims 1 thru | or 6,
A position sensorless control apparatus for a brushless motor, wherein the control means performs phase control with emphasis on driving efficiency in the PWM control region, and performs control to advance the energization phase in the high-speed rotation emphasis control region. In any one of Claims 1 thru | or 6,
A position sensorless control device for a brushless motor, wherein the control means is constituted by a microcomputer having a plurality of input / output ports. In any one of Claims 1 thru | or 6,
A position sensorless control device for a brushless motor, wherein the control means is composed of a hybrid IC having a plurality of input / output ports.   An air conditioner comprising a compressor and / or a blower that uses a brushless motor that is controlled by the brushless motor control device according to any one of claims 1 to 6 as a power source.   A refrigerating machine comprising a compressor and / or a blower that uses a brushless motor controlled by the brushless motor control device according to any one of claims 1 to 6 as a power source.   A washing machine comprising a brushless motor that is controlled by the brushless motor control device according to any one of claims 1 to 6 as a power source. A device that is controlled by the brushless motor control device according to any one of claims 1 to 6.

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