JP2006033946A - Controller of brushless motor and vehicle fan motor apparatus and control method of brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller of a brushless motor for stably activating the brushless motor even if power is supplied from a power supply and fluctuated. <P>SOLUTION: The controller 30 of the brushless motor 20 rotates a rotor 22 without a sensor, and is provided with a power detecting means 39 for outputting a power detection signal Ed corresponding to power supplied from the power supply 40, and motor control means 30B, 30C for detecting a power fluctuation in the power supply 40 based on the power detection signal Ed outputted from the power detecting means 39, varying PWM duty ratios of drive signals Sup-Swn if power supplied from the power supply 40 is fluctuated when the permanent magnet rotor 22 is compulsorily rotated, and maintaining fixed power supplied to stator windings 21u, 21v, 21w. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a brushless motor control device, a vehicle fan motor device, and a brushless motor control method, and more particularly, to a sensorless brushless motor control device, a vehicle fan motor device, and a brushless motor control method.

  Conventionally, the rotational position of the rotor is detected not by using a rotational position detector such as a Hall element, but by detecting an induced voltage induced in the stator winding during the steady rotation of the rotor. A sensorless brushless motor device is known (see, for example, Patent Document 1).

  For example, in the example described in Patent Document 1, an induced voltage induced in a stator winding during steady rotation of a rotor is detected by an induced voltage detector, and based on an induced voltage signal output from the induced voltage detector. Thus, the switching signal is generated to control the rotor speed.

  By the way, in the above-described sensorless type brushless motor device, since the induced voltage is not induced in the stator winding in a state where the rotor is stopped, it is impossible to detect the rotational position of the rotor.

Therefore, in the example described in Patent Document 1, the switching signal generated based on the synchronization signal is applied to the inverter circuit to forcibly drive the rotor and then induced in the stator winding. A switching signal is generated based on the induced voltage to switch to sensorless driving for controlling the speed of the rotor.
JP-A-5-219784 (page 3-4, FIG. 1)

  However, the so-called sensorless type brushless motor device as described above can start up stably under a situation where the power supply is stable, but for example, under a situation where the power supply fluctuates like a vehicle. Then, there is a possibility that it cannot start stably. That is, if there is not enough power supply, it may not be able to start, and if the power supply is excessive, an excessive current may flow through the brushless motor and the stator windings may be damaged.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a brushless motor in a control device for controlling a so-called sensorless brushless motor even when the power supplied from the power supply device fluctuates. It is an object of the present invention to provide a brushless motor control device capable of stably starting a motor.

  Another object of the present invention is to stabilize the brushless motor even when the power supplied from the vehicle power supply battery fluctuates in a vehicle fan motor device equipped with a so-called sensorless brushless motor mounted on a vehicle. An object of the present invention is to provide a fan motor device for a vehicle that can be started up.

  Furthermore, another object of the present invention is a control method for controlling a so-called sensorless brushless motor, which can stably start the brushless motor even when the power supplied from the power supply device fluctuates. Another object of the present invention is to provide a control method for a brushless motor.

  According to the brushless motor control device of the first aspect, the problem is that the permanent magnet rotor is forcibly rotated by sequentially generating a drive magnetic field in the stator winding based on the synchronization signal when the brushless motor is started. And a brushless motor in which the permanent magnet rotor is rotated in a sensorless manner by sequentially switching the driving magnetic field of the stator winding based on the induced voltage induced in the stator winding during steady rotation of the brushless motor. A motor control device that detects power supplied from a power supply device and outputs a power detection signal corresponding to the detected power, and based on the power detection signal output from the power detection device A power supply fluctuation is detected in the power supply device, and the power supplied to the stator windings when the permanent magnet rotor is forcibly rotated is unified. Further comprising a motor control means for holding the, is solved by.

  As described above, the brushless motor control device according to the present invention detects the power supplied from the power supply device and outputs a power detection signal corresponding to the detected power, and the power detection means outputs the power detection signal. Motor control means for detecting power fluctuations in the power supply device based on a power supply detection signal, and maintaining constant power supplied to the stator windings when the permanent magnet rotor is forcibly rotated Therefore, even if the power supplied from the power supply device fluctuates when the permanent magnet rotor is forcibly rotated, the power supplied from the power supply device is kept constant. And can be supplied to the stator winding. Therefore, the power supplied to the stator windings when the permanent magnet rotor is forcibly rotated is constant.

  In the present invention, when the permanent magnet rotor is forcibly rotated, when the permanent magnet rotor is forcibly started in addition to when the permanent magnet rotor is continuously rotated, It is a concept that also includes

  According to a second aspect of the present invention, more specifically, the motor control means includes an inverter circuit connected to the stator winding and a plurality of switching elements and rectifier elements being bridge-connected, and a stator winding. A switching signal generation circuit that outputs a switching signal to the inverter circuit based on an induced voltage induced in the wire, and the switching signal generation circuit supplies the stator winding by changing the PWM duty ratio of the switching signal The power supply to be held is kept constant. With such a configuration, even when the power supplied from the power supply device fluctuates, the power supplied to the stator winding can be reliably held constant. Further, since the power supply is corrected by changing the PWM duty ratio output to the inverter circuit in which the switching element and the rectifying element are bridge-connected, the power supply is compared with the structure in which the power supply is corrected by a power supply regulator or the like. Loss can be kept low.

  Further, as described in claim 3, before the motor control means forcibly rotates the permanent magnet rotor, a predetermined phase of the stator winding is energized to rotate the permanent magnet rotor in advance. If it is configured to rotate to the position, the permanent magnet rotor can be forcibly started in a state where the phases of the permanent magnet rotor and the stator are matched. Thereby, it becomes possible to start the permanent magnet rotor smoothly.

  Further, as described in claim 4, when the motor control means forcibly rotates the permanent magnet rotor, the period of energizing the stator winding is gradually shortened to rotate the permanent magnet rotor. When the number is increased, the phase of the induced voltage signal induced in the stator winding is changed to the phase of the synchronization signal for sequentially generating a magnetic field in the stator winding when the permanent magnet rotor is forcibly started. It is possible to make the state close to or coincide with each other. As a result, when the permanent magnet rotor is forcibly activated, the phase of the synchronization signal for sequentially generating a magnetic field in the stator winding is close to or coincident with the phase of the induced voltage signal induced in the stator winding. Thus, it is possible to shift from forced driving to sensorless driving.

  In addition, as described in claim 5, when the motor control means forcibly rotates the permanent magnet rotor and the rotational speed of the permanent magnet rotor exceeds a predetermined value, the stator winding When the permanent magnet rotor is configured to rotate in a sensorless manner by sequentially switching the driving magnetic field of the stator winding based on the induced voltage, the stator winding is It is possible to shift from forced driving to sensorless driving in a state in which the phase of the synchronization signal for generating the magnetic field sequentially approaches or matches the phase of the induced voltage signal induced in the stator winding. This makes it possible to smoothly transition from the forced drive state to the sensorless drive state without causing problems such as step-out and motor stop.

  According to a sixth aspect of the present invention, a fan motor including a brushless motor, a fan that rotates as the fan motor rotates, a controller that drives the fan motor, and a vehicle power supply battery that supplies power to the controller, In the vehicular fan motor apparatus comprising the above, it is preferable to use the brushless motor control apparatus according to any one of claims 1 to 5 as the controller.

  Thus, the vehicle fan motor device of the present invention uses the brushless motor control device according to any one of claims 1 to 5 as a controller for driving the fan motor. When the permanent magnet rotor is forcibly rotated, the power supplied to the stator windings can be kept constant even if the power supplied from the vehicle power supply battery fluctuates.

  Further, according to the brushless motor control method according to claim 7, the subject is a stator having a stator winding for generating a driving magnetic field, and a drive having a permanent magnet and generated from the stator winding. An initial position for energizing a predetermined phase of the stator winding to rotate the permanent magnet rotor to a predetermined rotational position. And a step of generating a driving magnetic field sequentially in the stator winding based on the synchronization signal to forcibly rotate the permanent magnet rotor and detecting the power supplied from a power supply device to detect the stator. A forcible driving step for maintaining a constant power supply to be supplied to the winding; and the fixed magnet when the rotational speed of the permanent magnet rotor exceeds a predetermined value by forcibly rotating the permanent magnet rotor. It is provided with a sensor-less driving step of sequentially switching the driving magnetic field of the stator winding based on the induced voltage induced in the windings is rotated by the sensorless system of the permanent magnet rotor, and is solved by.

  As described above, in the brushless motor control method of the present invention, before the permanent magnet rotor is forcibly rotated, a predetermined phase of the stator winding is energized to set the permanent magnet rotor to a predetermined rotational position. Therefore, the permanent magnet rotor can be forcibly started in a state where the phases of the permanent magnet rotor and the stator are matched. Thereby, it becomes possible to start the permanent magnet rotor smoothly.

  In the present invention, even if the power supplied from the power supply device fluctuates when the permanent magnet rotor is forcibly rotated, the power is supplied to the stator winding by correcting it to a constant power. Can be supplied. Therefore, the power supplied to the stator windings when the permanent magnet rotor is forcibly rotated is constant.

  Further, according to the present invention, when the rotation speed of the permanent magnet rotor exceeds a predetermined value by forcibly rotating the permanent magnet rotor, it is based on the induced voltage induced in the stator winding. Since the permanent magnet rotor is rotated in a sensorless manner by sequentially switching the driving magnetic field of the stator winding, the phase of the synchronization signal for generating a magnetic field in the stator winding at the time of forced activation of the permanent magnet rotor is fixed to the stator. It is possible to shift from forced driving to sensorless driving in a state close to the phase of the induced voltage signal induced in the winding. As a result, the brushless motor can be smoothly shifted from the forced drive state to the sensorless drive state.

  Thus, according to the present invention, even when the power supplied from the power supply device fluctuates when the permanent magnet rotor is forcibly rotated, the power supplied to the stator winding is constant. Therefore, the brushless motor can be started stably. As a result, it is possible to prevent a problem that the brushless motor cannot be started or a problem that an excessive current flows through the brushless motor and the stator windings are damaged.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be noted that members, arrangements, and the like described below do not limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention.

  FIG. 1 to FIG. 5 are diagrams showing an embodiment of the present invention, FIG. 1 is an explanatory view showing the configuration of the vehicle fan motor device, FIG. 2 is a flowchart showing the operation flow of the vehicle fan motor device, FIG. Is an explanatory diagram showing an induced voltage signal induced in the brushless motor, FIG. 4 is an explanatory diagram showing a rotational position detection signal and a drive signal, and FIG. 5 is an explanatory diagram showing a voltage supplied to the brushless motor.

First, the configuration of a vehicle fan motor device according to an embodiment of the present invention will be described with reference to FIG.
A vehicle fan motor device S according to an embodiment of the present invention shown in FIG. 1 is preferably used as a cooling device that cools a radiator of an engine provided in a vehicle (not shown), for example. And a fan motor 20, a controller 30 as a control device, a vehicle power supply battery 40 as a power supply device, and a host controller 50.

  The fan 10 is disposed in the vicinity of an engine radiator provided in a vehicle (not shown), and includes a blade 11 and a rotating shaft 12. The blades 11 are formed radially on the rotary shaft 12, and the rotary shaft 12 is connected to the rotor 22 of the fan motor 20. The fan 10 of this example can rotate as the fan motor 20 is driven.

  The fan motor 20 includes a stator 21 that generates a driving magnetic field and a rotor 22 that rotates by the driving magnetic field generated from the stator 21. The stator 21 is provided with U-phase, V-phase, and W-phase stator windings 21u, 21v, and 21w connected in a Y-shape, and the rotor 22 has an N pole and an S pole. A permanent magnet (not shown in FIG. 1) provided with one pole is provided.

  The controller 30 is supplied with power from the vehicle power supply battery 40 and drives the fan motor 20 and is constituted by, for example, a one-chip electric circuit, a small control device, or the like. The controller 30 of this example includes an inverter circuit 30A, a driver circuit 30B, a motor control circuit 30C, a rotational position detection circuit 30D, a filter circuit 30E, and a power supply detector 30F as main components. Yes.

  The inverter circuit 30A, the driver circuit 30B, and the motor control circuit 30C constitute a motor control unit according to the present invention, and the driver circuit 30B and the motor control circuit 30C constitute a switching signal generation circuit according to the present invention. .

  The inverter circuit 30A is configured by a so-called full-wave drive circuit in which an upper arm and a lower arm are bridge-connected. That is, the upper arm of the inverter circuit 30A is composed of switching elements 33a, 33b, 33c and diodes 34a, 34b, 34c, and the lower arm is composed of switching elements 33d, 33e, 33f and diodes 34d, 34e, 34f. Yes.

  The switching elements 33a to 33f are configured by n-channel MOSFETs, and are bridge-connected between the anode power supply line 35a and the cathode power supply line 35b in three phases of U phase, V phase, and W phase. The drains of the switching elements 33a, 33b, and 33c are connected to the anode power supply line 35a, and the sources of the switching elements 33d, 33e, and 33f are connected to the cathode power supply line 35b.

  The gates of the switching elements 33a to 33f are respectively connected to the output terminal of the driver circuit 30B. The intermediate part of each bridge connection between the switching elements 33a, 33b, 33c and the switching elements 33d, 33e, 33f is the controller 30. Are connected to the stator windings 21u, 21v, and 21w via the external output terminals 32u, 32v, and 32w, respectively.

  Switching elements 33a, 33b and 33c switch the flow of current from anode power supply line 35a to stator windings 21u, 21v and 21w based on a switching signal applied to the gate. The switching elements 33d, 33e, and 33f switch the flow of current from the stator windings 21u, 21v, and 21w to the cathode power supply line 35b based on a switching signal given to the gate.

  The diodes 34a to 34f are for releasing a surge voltage generated by switching of the switching elements 33a to 33f. The diodes 34a to 34f in this example are connected in parallel to the switching elements 33a to 33f, respectively, and are wired so as to be in the opposite direction to the current flow from the anode power supply line 35a to the cathode power supply line 35b. . The diodes 34a to 34f are built in the switching elements 33a to 33f made of MOSFETs, respectively.

  Neutral potential generating resistors 36a and 36b are connected in series between the anode power supply line 35a and the cathode power supply line 35b. The neutral potential generating resistors 36a and 36b are for generating a neutral potential of the induced voltage generated in the stator windings 21u, 21v, and 21w. Intermediate connection portions of the neutral potential generation resistor 36a and the neutral potential generation resistor 36b are connected to comparators 38u, 38v, and 38w of a rotational position detection circuit 30D, which will be described later, via signal lines, respectively.

  The driver circuit 30B is for switching the switching element switching elements 33a to 33f, and according to the drive signals Sup, Svp, Swp, Sun, Svn, Swn (see FIG. 4) output from the motor control circuit 30C. A predetermined switching signal is generated, and the switching signal is output to the gates of the switching elements 33a to 33f.

  The motor control circuit 30C is configured by, for example, a microcomputer, and includes a calculation unit 37a, a buffer memory 37b, and a timer 37c. The calculation unit 37a performs a predetermined calculation based on the control signal Sa output from the host controller 50 and is output from the rotation position detection signals Eu, Ev, Ew output from the rotation position detection circuit 30D or the timer 37c. Based on the synchronization signal, six-phase drive signals Sup, Svp, Swp, Sun, Svn, and Swn are generated (see FIG. 4).

  As will be described in detail later, the buffer memory 37b has an area for storing the voltage correction value (PWM duty ratio) calculated by the calculation unit 37a and an area for setting a flag indicating the driving state of the fan motor 20. Is formed. There are three types of driving states of the fan motor 20 in this example: a stopped state, a forced driving state, and a sensorless driving state. These states are stored in the storage area of the buffer memory 37b. The timer 37c receives the control signal Sa from the host controller 50 and outputs a synchronization signal to the calculation unit 37a. Details of the operation of the motor control circuit 30C will be described later.

  The rotational position detection circuit 30D detects an induced voltage induced in the stator windings 21u, 21v, and 21w according to the rotation of the rotor 22, and includes comparators 38u, 38v, and 38w. It is configured. The induced voltage signals Eu ', Ev', Ew '(see Fig. 3) generated in the stator windings 21u, 21v, 21w are input to one input terminals of the comparators 38u, 38v, 38w, respectively. Further, the reference voltage signal Es at the intermediate connection portion of the neutral potential generating resistor 36a and the neutral potential generating resistor 36b is input to the other input terminals of the comparators 38u, 38v, and 38w. The comparators 38u, 38v, 38w compare the magnitudes of the induced voltage signals Eu ′, Ev ′, Ew ′ and the reference voltage signal Es (see FIG. 3 above) to generate a zero cross signal, which is used as a rotational position detection signal. It outputs to the motor control circuit 30C as Eu, Ev, Ew (see FIG. 4).

  The filter circuit 30E includes an inductor L1 and capacitors C1 and C2. The inductor L1 and the capacitors C1 and C2 are for suppressing the noise current generated in the anode power supply line 35a and the cathode power supply line 35b from flowing to the vehicle power supply battery 40 due to the switching operation of the inverter circuit 30A. . In the controller 30 of this example, the filter circuit 30E can prevent other devices connected to the vehicle power supply battery 40 from malfunctioning due to switching noise of the inverter circuit 30A.

  The controller 30 is provided with power terminals 31n and 31p, and a cathode power line 42 and an anode power line 41 connected to the vehicle power battery 40 are connected to the power terminals 31n and 31p, respectively. The anode power line 35a in the controller 30 is connected to a power detector 30F as a power detector. The power supply detector 30F is configured to output a power supply detection signal Ed corresponding to a change in power supply in the vehicle power supply battery 40 to the motor control circuit 30C.

  The vehicle power supply battery 40 is configured by an in-vehicle DC storage battery, and is configured to supply predetermined power (for example, an output voltage of 12 V) to the fan motor 20 and the controller 30.

  The host controller 50 is composed of an arithmetic processing circuit including a CPU, a memory, and the like, and inputs an output signal from a cooling water temperature sensor or a vehicle speed sensor disposed in a radiator (not shown). Then, the control signal Sa indicating the command rotational speed is generated. The control signal Sa from the host controller 50 is input to the motor control circuit 30C through the signal line and the input terminal 31a.

  The host controller 50 and the vehicle power supply battery 40 are connected to each other via an ignition switch 64 and a fuse 65 provided in a vehicle (not shown), and an anode power supply that connects the controller 30 and the vehicle power supply battery 40. The line 41 is provided with a fuse 66 for preventing overcurrent.

Next, the operation of the vehicle fan motor apparatus S configured as described above will be described with reference to FIGS.
1. Regarding the process of starting the initial position from the stop state and then shifting to the forced drive First, in the calculation unit 37a of the motor control circuit 30C provided in the controller 30, it is determined whether or not the rotational speed of the fan motor 20 is 0 rpm. (Step S1). Here, the calculation unit 37a counts the synchronization signal output from the timer 37c.

  When the rising edge or falling edge of the rotational position detection signals Eu, Ev, Ew (see FIG. 3) is detected before the count value becomes constant, the rotational speed of the fan motor 20 exceeds 0 rpm. Judgment is made. On the other hand, if the count value overflows before the rising edge or the falling edge of the rotational position detection signals Eu, Ev, Ew (see FIG. 3) is detected, it is determined that the rotational speed of the fan motor 20 is 0 rpm. To do.

  Here, when it is determined that the rotation speed of the fan motor 20 is 0 rpm (step S1: NO), it is determined whether or not the current stage state is a forced drive state (step S2). Here, the calculation unit 37a determines the driving state of the fan motor 20 by checking whether or not the flag indicating the forced driving state is set in the storage area of the buffer memory 37b.

  In the initial state, a flag indicating a stop state is set as a default in the storage area of the buffer memory 37b. Therefore, in the first routine process, it is determined in step S2 that the flag indicating the forced drive state is not set in the storage area of the buffer memory 37b (step S2: NO).

  If it is determined in the process of step S2 that the flag indicating the forced drive state is not set in the storage area of the buffer memory 37b (step S2: NO), a stop state is set in the storage area of the buffer memory 37b. The flag shown is set (step S3). Since the flag indicating the stop state is already set in the storage area of the buffer memory 37b as a default, in the first process, the process proceeds to the process of step S4 substantially without performing the process of step S3.

  In the process of step S4, it is determined whether or not there is a command rotational speed (control signal Sa) from the host controller 50 (step S4). If it is determined that there is a command rotational speed from the host controller 50 (step S4: YES), it is determined whether or not the current stage state is a sensorless drive state (step S5). Here, the computing unit 37a determines the driving state of the fan motor 20 by checking whether or not the flag indicating the sensorless driving state is set in the storage area of the buffer memory 37b.

  In the initial state, as described above, the flag indicating the stop state is set as the default in the storage area of the buffer memory 37b. Therefore, in step S5, the sensorless drive state is indicated in the storage area of the buffer memory 37b. It is determined that the flag is not set (step S5: NO).

  Subsequently, the rotational speed of the fan motor 20 is detected, and it is determined whether the rotational speed of the fan motor 20 is equal to or lower than a predetermined limit rotational speed (step S6). Since the rotation speed is zero when the fan motor 20 is stopped in the first process (the state where there is no idling or the like), the rotation speed of the fan motor 20 is set to a predetermined limit rotation in the process of step S6. It is determined that the number is less than or equal to the number (step S6: YES).

  Then, it is determined whether or not the fan motor 20 is in a forced drive state (step S7). Here, as described above, since the flag indicating the stop state is already set in the storage area of the buffer memory 37b as a default, the flag indicating the forced drive state is set in the storage area of the buffer memory 37b in the process of step S7. It is determined that it is not set (step S7: NO). Subsequently, an initial position is set to position the rotor 22 of the fan motor 20 at a predetermined rotational position (steps S8 to S11).

  To perform the initial position setting, first, the motor output initial value is set in the calculation unit 37a. At this time, the calculating part 37a detects the output voltage from the vehicle power supply battery 40 by detecting the power supply detection signal Ed output from the power supply detector 30F. And the PWM duty ratio from which the voltage supplied to the fan motor 20 becomes a predetermined voltage initial value (eg, 3.6 V; see FIG. 5) with respect to the output voltage from the vehicle power supply battery 40 is calculated. This is the motor output initial value.

  For example, when the output voltage of the vehicle power supply battery 40 is 12V, the motor output initial value (PWM duty ratio) is set to 30%. Thereby, the motor voltage supplied to the fan motor 20 can be 3.6V. Then, the motor output initial value set as described above is used as a voltage correction value (step S8), and this voltage correction value is stored in the buffer memory 37b (step S9).

  Subsequently, the calculation unit 37a sets the voltage correction value (in this case, PWM duty ratio 30%) stored in the buffer memory 37b as the motor output value (step S10). In this example, PWM chopping having a PWM duty ratio represented by the motor output value is superimposed on the drive signals Sup, Svp, Swp, Sun, Svn, Swn. Then, the drive signals Sup, Svp, Swp, Sun, Svn, Swn on which the PWM chopping is superimposed are output to the driver circuit 30B. At this time, drive signals Sup, Svp, Swp, Sun, Svn, Swn are output so as to energize a predetermined phase of the fan motor 20.

  As a result, a driving magnetic field is generated in the rotor 22, and the rotor 22 is positioned at a predetermined rotational position so that the phases of the rotor 22 and the stator 21 coincide with each other. As described above, in this example, the initial position is determined by positioning the rotor 22 at a predetermined rotational position so that the phases of the rotor 22 and the stator 21 coincide with each other. When the initial position is set in this way, the rotor 22 can be forcibly started in a state in which the phases of the rotor 22 and the stator 21 coincide with each other, as will be described later. Accordingly, it is possible to smoothly start the rotor 22.

  Further, in this example, even when the output voltage supplied from the vehicle power supply battery 40 varies when performing the initial position adjustment, as described above, it is corrected to a constant voltage and this is fixed to the stator winding. 21u, 21v, 21w can be supplied. Therefore, even when a power supply fluctuation occurs when the initial position of the rotor 22 is performed, the voltage supplied to the stator windings 21u, 21v, and 21w can be made constant. Therefore, the initial position of the rotor 22 can be surely performed.

  Then, it is determined whether or not the initial position of the rotor 22 has been finished (step S11). Whether or not the initial position adjustment has been completed is determined by counting the synchronization signal output from the timer 37c in the calculation unit 37a and elapse of a predetermined time. If it is determined that the initial position adjustment has been completed (step S11: YES), the fan motor 20 is shifted to the forced drive state (steps S12 to S15). At this time, first, a flag indicating the forced drive state is set in the storage area of the buffer memory 37b (step S12).

  Next, the motor output initial value is set in the calculation unit 37a, and this is set as a voltage correction value (step S13). In the first routine processing, as described above, the motor output initial value (PWM duty ratio 30%) used when the initial position adjustment is performed is used as the voltage correction value. Subsequently, the voltage correction value is stored in the buffer memory 37b (step S14). Here, the motor output initial value (PWM duty ratio 30%) used when the initial position adjustment is performed is stored in the buffer memory 37b as a voltage correction value.

  Then, the calculation unit 37a sets the voltage correction value (in this case, PWM duty ratio 30%) stored in the buffer memory 37b as the motor output value (step S15). In this example, PWM chopping having a PWM duty ratio represented by the motor output value is superimposed on the drive signals Sup, Svp, Swp, Sun, Svn, Swn (see FIG. 4). Then, the drive signals Sup, Svp, Swp, Sun, Svn, Swn on which the PWM chopping is superimposed are output to the driver circuit 30B. At this time, the PWM chopping is superimposed on one or both of the drive signals Sup, Svp, Swp and the drive signals Sun, Svn, Swn. Note that the drive signals Sup, Svp, Swp, Sun, Svn, and Swn during forced driving are generated in synchronization with the synchronization signal output from the timer 37c.

  In this way, when the drive signals Sup, Svp, Swp, Sun, Svn, Swn on which PWM chopping is superimposed are output from the motor control circuit 30C to the driver circuit 30B, the gates of the switching elements 34a to 34f are output by the driver circuit 30B. A switching signal is output. Thereby, the switching elements 34a to 34f are sequentially switched.

  When the switching elements 34a to 34f are sequentially switched, a current flows through the stator windings 21u, 21v, and 21w in a predetermined order. Among the stator windings 21u, 21v, and 21w, the stator that has a current flowed. A driving magnetic field is generated from the winding, and forced driving of the fan motor 20 is started. At this time, since the switching elements 34a to 34c of the upper arm or the switching elements 34d to 34f of the lower arm are PWM chopped, the apparent voltage output to the fan motor 20 is maintained at 3.6V.

  As described above, in this example, even when the output voltage supplied from the vehicle power supply battery 40 varies during forced driving, as described above, the output voltage is corrected to a constant voltage and this is fixed to the stator winding 21u, 21v and 21w can be supplied. Therefore, even when a power supply fluctuation occurs when the rotor 22 is forcibly started, the voltage supplied to the stator windings 21u, 21v, 21w can be made constant, so that the fan motor 20 can be stably operated. Can be activated.

  In this example, the PWM duty ratio output to the inverter circuit 30A in which the switching elements 33a to 33f and the diodes 34a to 34f are bridge-connected is varied to be supplied to the stator windings 21u, 21v, and 21w. Since the configuration is such that the voltage is corrected, for example, the power loss can be reduced compared to a configuration where the voltage is corrected by a power regulator or the like.

  Subsequently, the switching timing of the drive signals Sup, Svp, Swp, Sun, Svn, Swn is subtracted based on the synchronization signal from the timer 37c (step S16). That is, the cycle of the drive signals Sup, Svp, Swp, Sun, Svn, Swn is set and updated to a value obtained by subtracting a predetermined subtracted value from the cycle of the currently output drive signals Sup, Svp, Swp, Sun, Svn, Swn. To do. As a result, the timing of energizing the stator windings 21u, 21v, 21w is advanced, and the rotational speed of the fan motor 20 is increased. Then, the process proceeds to step S1.

2. About processing at the time of forcible driving When the stator 21 of the fan motor 20 is forcibly rotated as described above, the rotor 22 starts to rotate. In the state where the rotor 22 is forcibly rotating in this way, the rotational speed of the fan motor 20 exceeds 0 rpm. Thus, the rotational speed of the fan motor 20 is increased in the process of step S1. It is determined that it exceeds 0 rpm (step S1: YES).

  Subsequently, the presence / absence of a command rotational speed from the host controller 50 is determined (step S4). Here, when there is no command rotation speed from the host controller 50, it is determined that there is no command rotation speed from the host controller 50 (step S4: NO), and the voltage correction value (NO in step S4) is stored in the buffer memory 37b. The PWM duty ratio is cleared (step S17). Then, a flag indicating a stop state is set in the storage area of the buffer memory 37b (step S18), and the process proceeds to step S1.

  On the other hand, if the command rotational speed from the host controller 50 continues, it is determined that there is a command rotational speed from the host controller 50 (step S4: YES). Subsequently, it is determined whether or not a flag indicating a sensorless driving state is set in the storage area of the buffer memory 37b (step S5). At this time, in the state where the drive of the fan motor 20 is forcibly started as described above, a flag indicating the forced drive state is set in the storage area of the buffer memory 37b in step S12. Therefore, in the process of step S5, it is determined that the flag indicating the sensorless driving state is not set in the storage area of the buffer memory 37b (step S5: NO).

  Subsequently, the rotational speed of the fan motor 20 is detected, and it is determined whether the rotational speed of the fan motor 20 is equal to or lower than a predetermined limit rotational speed (step S6). Here, in a state where the fan motor 20 is forcibly driven, if it is determined that the rotation speed of the fan motor 20 is equal to or less than a predetermined limit rotation speed (step S6: YES), the fan motor 20 is forced. It is determined whether or not it is in a driving state (step S7). At this time, since the flag indicating the forced drive state is set in the storage area of the buffer memory 37b in the process of step S12, the flag indicating the forced drive state is set in the storage area of the buffer memory 37b in the process of step S7. (Step S7: YES).

  And the voltage correction value is set in the calculating part 37a (step S19). That is, the arithmetic unit 37a detects the output voltage from the vehicle power supply battery 40 by detecting the power supply detection signal Ed output from the power supply detector 30F. And the PWM duty ratio from which the voltage supplied to the fan motor 20 becomes a predetermined voltage initial value (eg, 3.6 V; see FIG. 5) with respect to the output voltage from the vehicle power supply battery 40 is calculated. This is the voltage correction value.

  For example, when a load or the like is applied to the vehicle power supply battery 40 and the voltage output from the vehicle power supply battery 40 is reduced from 12 V to 6 V, the voltage correction value (PWM duty ratio) is set to 60%. . Thereby, the apparent motor voltage supplied to the fan motor 20 can be maintained at 3.6V. Then, the voltage correction value set as described above is stored in the buffer memory 37b (step S14).

  Then, the calculation unit 37a sets the voltage correction value (in this case, the PWM duty ratio 60%) stored in the buffer memory 37b as the motor output value (step S15). In this example, PWM chopping having a PWM duty ratio represented by the motor output value is superimposed on the drive signals Sup, Svp, Swp, Sun, Svn, Swn (see FIG. 4). Then, the drive signals Sup, Svp, Swp, Sun, Svn, Swn on which the PWM chopping is superimposed are output to the driver circuit 30B. At this time, the PWM chopping is superimposed on one or both of the drive signals Sup, Svp, Swp and the drive signals Sun, Svn, Swn. Thereby, the voltage supplied to the fan motor 20 is maintained at 3.6 V, and the forced drive of the fan motor 20 is continued.

  As described above, in this example, even when the output voltage supplied from the vehicle power supply battery 40 varies during forced driving, as described above, the output voltage is corrected to a constant voltage and this is fixed to the stator winding 21u, 21v and 21w can be supplied. Therefore, even when the power supply fluctuates when the rotor 22 is forcibly rotated, the voltage supplied to the stator windings 21u, 21v, 21w can be made constant, so that the fan motor 20 is stabilized. And can be rotated.

  Subsequently, the switching timing of the drive signals Sup, Svp, Swp, Sun, Svn, Swn is subtracted based on the synchronization signal from the timer 37c (step S16). As a result, the timing of energizing the stator windings 21u, 21v, 21w is advanced, and the rotational speed of the fan motor 20 further increases. And it transfers to the process of said step S1, and performs the process which concerns on the forced drive of said step S1, step S4-step S7, step S19, step S14-step S16 again. At this time, until the rotational speed of the fan motor 20 exceeds a predetermined limit rotational speed in step S6, the process related to the forced drive in steps S1, S4 to S7, step S19, and steps S14 to S16 is performed. .

3. Regarding the process of shifting from forced drive to sensorless drive The number of revolutions in the forced drive of the fan motor 20 can be determined by repeatedly performing the process related to forced drive in the above-described step S1, step S4 to step S7, step S19, and step S14 to step S16. If it rises, the rotation speed of the fan motor 20 will eventually exceed a predetermined limit rotation speed. The limit rotational speed is such that the phase difference between the rotational position detection signals Eu, Ev, Ew output from the rotational position detection circuit 30D and the drive signals Sup, Svp, Swp, Sun, Svn, Swn is less than a predetermined value (or phase). Is the predetermined number of revolutions.

  Next, while repeatedly performing the process related to the forced drive in the above-described step S1, step S4 to step S7, step S19, and step S14 to step S16, the rotational speed of the fan motor 20 is determined in advance in step S6. If it is determined that the number has been exceeded (step S6: NO), it is determined whether or not the fan motor 20 is in a forced drive state (step S20). Here, as described above, since the flag indicating the forced drive state is set in the storage area of the buffer memory 37b in step S12, it is determined in the process of step S20 that the forced drive state is set (step S20: YES).

  If it is determined in the process of step S20 that the motor is in the forced drive state (step S20: YES), the fan motor 20 is shifted to the sensorless drive state (steps S21 to S22). As described above, in this example, the phase of the synchronization signal (output from the timer 37c) for sequentially generating a magnetic field in the stator windings 21u, 21v, 21w when the rotor 22 is forcibly started is set to the stator windings 21u, 21v. , 21 w can be shifted from forced drive to sensorless drive in a state close to or in agreement with the phases of the induced voltage signals Eu, Ev, Ew. Therefore, it is possible to smoothly shift from the forced drive state to the sensorless drive state without causing problems such as step-out and motor stoppage.

  If it is determined in step S20 that the forced drive state is set (step S20: YES), first, a flag indicating the sensorless drive state is set in the storage area of the buffer memory 37b (step S21). Subsequently, the calculation unit 37a sets the output offset value as the motor output value. The output offset value at this time is a voltage correction value (for example, PWM duty ratio 60%; see FIG. 5) stored in the buffer memory 37b in the last routine process of the forced drive state immediately before shifting to the sensorless drive state. .

  In this example, PWM chopping having a PWM duty ratio represented by the motor output value is superimposed on the drive signals Sup, Svp, Swp, Sun, Svn, Swn (see FIG. 4). Subsequently, the drive signals Sup, Svp, Swp, Sun, Svn, Swn on which PWM chopping is superimposed are output to the driver circuit 30B. At this time, the PWM chopping is superimposed on one or both of the drive signals Sup, Svp, Swp and the drive signals Sun, Svn, Swn. Note that the drive signals Sup, Svp, Swp, Sun, Svn, Swn during sensorless driving are generated in synchronization with the rotational position detection signals Eu, Ev, Ew output from the rotational position detection circuit 30D.

  In this way, when the drive signals Sup, Svp, Swp, Sun, Svn, Swn on which PWM chopping is superimposed are output from the motor control circuit 30C to the driver circuit 30B, the gates of the switching elements 34a to 34f are output by the driver circuit 30B. A switching signal is output to Thereby, the switching elements 34a to 34f are sequentially switched.

  When the switching elements 34a to 34f are sequentially switched, a current flows through the stator windings 21u, 21v, and 21w in a predetermined order. Among the stator windings 21u, 21v, and 21w, the stator that has a current flowed. A driving magnetic field is generated from the winding, and sensorless driving of the fan motor 20 is started. At this time, since the switching elements 34a to 34c of the upper arm or the switching elements 34d to 34f of the lower arm are PWM chopped, the apparent voltage output to the fan motor 20 is maintained at 3.6V.

  Thus, in this example, even when the output voltage supplied from the vehicle power supply battery 40 fluctuates when shifting to sensorless driving, the voltage is corrected to a constant voltage and fixed as described above. It can supply to the child windings 21u, 21v, 21w. Therefore, even when the power supply fluctuates when the rotor 22 is forcibly rotated, the voltage supplied to the stator windings 21u, 21v, 21w can be made constant, so that the fan motor 20 is stabilized. Thus, it is possible to shift to sensorless driving. Then, the PWM duty ratio is gradually increased from this state. As a result, the voltage supplied to the fan motor 20 increases and the torque of the fan motor 20 increases (see FIG. 5).

  Subsequently, the rotational speed of the fan motor 20 is detected based on the rotational position detection signals Eu, Ev, Ew output from the rotational position detection circuit 30D, and the detected rotational speed and a command rotational speed from the host controller are proportionally calculated. Based on the calculated value, control is performed so as to keep the rotational speed of the fan motor 20 constant (step S23). Then, the process proceeds to step S1.

4). Processing at the time of sensorless driving As described above, in the state where the sensorless driving of the fan motor 20 is performed, the flag indicating the sensorless driving state is set in the storage area of the buffer memory 37b in the processing of step S21. Therefore, in the process of step S5, it is determined that the fan motor 20 is in the sensorless driving state (step S5: YES).

  Subsequently, the calculation unit 37a detects the rotational speed of the fan motor 20 based on the rotational position detection signals Eu, Ev, and Ew output from the rotational position detection circuit 30D, and the detected rotational speed and the upper controller 50 The command rotational speed is proportionally calculated, and control is performed so as to keep the rotational speed of the fan motor 20 constant based on the calculated value (step S23). And it transfers to the process of said step S1, and performs the process regarding the sensorless drive of said step S1, step S4, step S5, and step S23 again. At this time, the processing related to sensorless driving in step S1, step S4, step S5, and step S23 is performed until there is no command rotation speed from the host controller in step S4.

  Although not specifically shown in FIG. 2, when the sensorless drive of the fan motor 20 is performed, the output voltage from the vehicle power supply battery 40 is detected by detecting the power supply detection signal Ed output from the power supply detector 30F. Of course, the voltage supplied to the fan motor 20 may be corrected to a predetermined value with respect to the output voltage from the vehicle power supply battery 40.

  When the command rotational speed from the host controller 50 is lost while the processes related to the sensorless drive in steps S1, S4, S5, and S23 are repeated, the command rotational speed from the host controller 50 is It is determined that there is no voltage (step S4: NO), and the voltage correction value (PWM duty ratio) stored in the buffer memory 37b is cleared (step S17). Subsequently, a flag indicating a stop state is set in the storage area of the buffer memory 37b (step S18), and the process proceeds to step S1.

5. 5-1 Regarding Other Processes 5-1 Transition Process from the State in which the Fan Motor 20 Spins Due to External Force to the Sensorless Drive State When a traveling wind (not shown) travels and receives the traveling wind, the fan motor 20 and the fan 10 are Idle. In this way, even if the fan 10 and the fan motor 20 are idling due to the running wind, the fan motor 20 is not actively controlled to rotate, so the storage area of the buffer memory 37b is not stored. The flag indicating the stop state remains set.

  Here, when the traveling speed of the vehicle increases, the amount of traveling wind hitting the fan 10 increases, so that the rotational speeds of the fan 10 and the fan motor 20 gradually increase. When the rotational speed of the fan motor 20 increases in this way, the rotational speed of the fan motor 20 shifts from forced driving to sensorless driving while the flag indicating the stop state remains set in the storage area of the buffer memory 37b. It may exceed the limit rotational speed that is the threshold.

  In this example, when the fan motor 20 is idling due to an external force and the idling speed exceeds the limit rotation number, the fan motor 20 is forcibly driven and is stopped from the idling state (idling state). Transition to the sensorless drive state at once. Hereinafter, a process of shifting from the stop state (idle state) to the sensorless drive state while omitting the forced drive will be described.

  When the fan 10 and the fan motor 20 are idled by receiving the traveling wind, it is determined that the rotational speed of the fan motor 20 exceeds 0 rpm in the process of step S1 (step S1: YES). Subsequently, the presence / absence of a command rotational speed from the host controller 50 is determined (step S4). As described above, when the command motor speed is output from the host controller 50 when the fan motor 20 is idling due to an external force such as traveling wind, the command rotation from the host controller 50 is performed in step S4. It is determined that there is a number (step S4: YES). In this case, it is subsequently determined whether or not the current state is a sensorless driving state (step S5).

  Here, as described above, even when the fan 10 and the fan motor 20 are idling by receiving the traveling wind, the fan motor 20 is not actively controlled to rotate. The flag indicating the stop state is still set in the storage area 37b. Therefore, in the process of step S5, it is determined that the flag indicating the sensorless driving state is not set in the storage area of the buffer memory 37b (step S5: NO).

  Subsequently, the rotational speed of the idling fan motor 20 is detected based on rotational position detection signals Eu, Ev, and Ew output from the rotational position detection circuit 30D, and the rotational speed of the fan motor 20 is set to a predetermined limit rotational speed. It is determined whether the following is true (step S6). If it is determined in step S6 that the rotation speed of the fan motor 20 has exceeded a predetermined limit rotation speed (step S6: NO), it is determined whether the fan motor 20 is in a forced drive state (step S6). S20). Here, as described above, since the flag indicating the stop state is set in the storage area of the buffer memory 37b, it is determined that the forced drive state is not established in the process of step S20 (step S20: NO).

  Then, the process proceeds to step S24, and a flag indicating the sensorless driving state is set in the storage area of the buffer memory 37b (step S24). Subsequently, the calculation unit 37a sets an offset value (PWM duty ratio). To set the offset value, first, the power supply detection signal Ed output from the power supply detector 30F is detected, and the output voltage from the vehicle power supply battery 40 is detected. Next, the PWM duty ratio is calculated such that the voltage supplied to the fan motor 20 becomes a predetermined voltage initial value (eg, 3.6 V; see FIG. 5) with respect to the output voltage from the vehicle power supply battery 40. . The calculated duty ratio is used as an offset value. For example, when the voltage output from the vehicle power supply battery 40 is 9 V, the offset value (PWM duty ratio) is set to 40%. This offset value is set as an output offset value (step S25).

  Subsequently, PWM chopping having a PWM duty ratio represented by the output offset value (in this case, 40% PWM duty ratio) is superimposed on the drive signals Sup, Svp, Swp, Sun, Svn, Swn (see FIG. 4). ). Then, the drive signals Sup, Svp, Swp, Sun, Svn, Swn on which the PWM chopping is superimposed are output to the driver circuit 30B. At this time, the PWM chopping is superimposed on one or both of the drive signals Sup, Svp, Swp and the drive signals Sun, Svn, Swn. Thereby, the voltage supplied to the fan motor 20 is maintained at 3.6 V, and sensorless driving of the fan motor 20 is started.

  Thus, in this example, when the fan motor 20 is idling due to an external force and the idling speed exceeds the limit rotational speed, the forcible drive of the fan motor 20 is omitted, and the sensorless from the stopped state (idling state) is performed at once. Transition to the driving state. Then, after shifting to sensorless driving, the rotational speed of the fan motor 20 is detected based on the rotational position detection signals Eu, Ev, Ew output from the rotational position detection circuit 30D, and the detected rotational speed and the host controller 50 are detected. The command rotational speed is proportionally calculated, and control is performed so as to keep the rotational speed of the fan motor 20 constant based on the calculated value (step S23). Then, the process proceeds to step S1.

5-2 Processing when the rotational speed of the fan motor 20 decreases in the forced drive state or the sensorless drive state In the vehicle fan motor device S of this example, when the rotational speed of the fan motor 20 is 50 rpm or less, the rotational position detection signal The count value is set to overflow before the rising edge or falling edge of Eu, Ev, Ew is detected. Therefore, when the rotational speed of the fan motor 20 is reduced due to the influence of disturbance or the like in the forced driving state or the sensorless driving state, and the rotational speed of the fan motor 20 becomes 50 rpm or less, the rotation of the fan motor 20 is performed in the calculation unit 37a. It is determined that the number is 0 rpm (step S1: NO).

  Here, when the rotational speed of the fan motor 20 decreases while in the forced drive state, the flag indicating the forced drive state is set in the storage area of the buffer memory 37b, so the forced drive is performed in the process of step S2. The state is determined (step S2: YES). In this case, thereafter, the process related to the forced drive in steps S4 to S7, step S19, and steps S14 to S16 is performed as described above.

  On the other hand, when the rotational speed of the fan motor 20 decreases in the sensorless drive state, the flag indicating the sensorless drive state is set in the storage area of the buffer memory 37b. (Step S2: NO). In this case, a flag indicating the stop state is set in the storage area of the buffer memory 37b, and thereafter, the processing related to the stop state in steps S4 to S18 is performed as described above.

As described above, according to the present embodiment, the following effects are obtained.
(A) According to the present embodiment, even when the output voltage supplied from the vehicle power source battery 40 during the forced driving is changed, the output voltage is corrected to a constant voltage and this is fixed to the stator windings 21u, 21v, 21w. Can be supplied to. Therefore, even when the power supply fluctuates when the rotor 22 is forcibly rotated, the voltage supplied to the stator windings 21u, 21v, 21w can be made constant, so that the brushless motor can be stabilized. Can be activated. As a result, it is possible to prevent a problem that the brushless motor cannot be started or a problem that an excessive current flows through the brushless motor and the stator windings are damaged.

  (B) According to the present embodiment, the stator windings 21u, 21v, and 21w are changed by varying the PWM duty ratio that is output to the inverter circuit 30A in which the switching elements 33a to 33f and the diodes 34a to 34f are bridge-connected. Therefore, for example, the power loss can be kept low compared to a configuration in which voltage is corrected by a power regulator or the like.

  (C) According to the present embodiment, before the rotor 22 is forcibly activated, the initial position is set so that the phases of the rotor 22 and the stator 21 coincide with each other. The rotor 22 can be forcibly activated with the phases matched. Accordingly, it is possible to smoothly start the rotor 22.

  (D) According to the present embodiment, the phase of the synchronization signal (output from the timer 37c) for sequentially generating a magnetic field in the stator windings 21u, 21v, 21w when the rotor 22 is forcibly started is set to the stator winding 21u. , 21v, 21w can be shifted from forced driving to sensorless driving in a state close to or in agreement with the phases of the induced voltage signals Eu, Ev, Ew. Therefore, it is possible to smoothly shift from the forced drive state to the sensorless drive state without causing problems such as step-out and motor stoppage.

The embodiment of the present invention can be modified as follows.
That is, in the above embodiment, the inverter circuit 30A is configured by a full-wave drive circuit, but the present invention is not limited to this. In addition, the inverter circuit 30A may be configured with a half-wave drive circuit.

The technical ideas other than the claims that can be grasped from the above embodiments will be described below.
In a brushless motor device comprising a brushless motor and a controller for driving the brushless motor,
A brushless motor device using the brushless motor control device according to any one of claims 1 to 5 as the controller.

  Thus, when the controller according to any one of claims 1 to 5 is used as a controller for driving the brushless motor, the permanent magnet rotor of the brushless motor is forcibly rotated. Sometimes, the power supplied to the stator winding can be kept constant even when the power supplied from the power supply device fluctuates.

It is explanatory drawing which shows the structure of the fan motor apparatus for vehicles which concerns on one Embodiment of this invention. It is a flowchart which shows the flow of operation | movement of the fan motor apparatus for vehicles which concerns on one Embodiment of this invention. It is explanatory drawing which shows the induced voltage signal induced by the brushless motor which concerns on one Embodiment of this invention. It is explanatory drawing which shows the rotational position detection signal and drive signal which concern on one Embodiment of this invention. It is explanatory drawing which shows the voltage supplied to the brushless motor which concerns on one Embodiment of this invention.

Explanation of symbols

10 fan, 11 blade, 12 rotating shaft, 20 brushless motor (fan motor), 21 permanent magnet stator (stator), 21u, 21v, 21w stator winding, 22 rotor, 30 brushless motor control device (controller) ), 30A inverter circuit, 30B driver circuit, 30C motor control circuit, 30D rotational position detection circuit, 30E filter circuit, 31a input terminal, 31n, 31p power supply terminal, 32u, 32v, 32w external output terminal, 33a, 33b, 33c, 33d, 33e, 33f Switching element, 34a, 34b, 34c, 34d, 34e, 34f Rectifier element (diode), 35a Anode power line, 35b Cathode power line, 36a, 36b Neutral potential generating resistor, 37a arithmetic unit, 37b buffer Memory, 37c Thailand , 38u, 38v, 38w comparator, 39 power detector, 40 vehicle power battery, 41 anode power line, 42 cathode power line, 50 host controller, 64 ignition switch, 65 fuse, 66 fuse, C1, C2 capacitor, L1 Inductor, S Fan motor for vehicle

Claims (7)

When the brushless motor is started, a driving magnetic field is sequentially generated in the stator winding based on the synchronization signal to forcibly rotate the permanent magnet rotor, and is induced in the stator winding during steady rotation of the brushless motor. A control device for a brushless motor in which a driving magnetic field of the stator winding is sequentially switched based on an induced voltage to rotate the permanent magnet rotor in a sensorless manner,
Power detection means for detecting the power supplied from the power supply device and outputting a power detection signal corresponding to the detected power;
Based on a power detection signal output from the power detection means, the power supply in the power supply device is detected, and the power supplied to the stator winding when the permanent magnet rotor is forcibly rotated Motor control means for maintaining a constant value;
A control apparatus for a brushless motor, comprising: The motor control means is connected to the stator winding, an inverter circuit in which a plurality of switching elements and rectifying elements are bridge-connected,
A switching signal generation circuit that outputs a switching signal to the inverter circuit based on an induced voltage induced in the stator winding, and
The brushless motor control according to claim 1, wherein the switching signal generation circuit is configured to maintain a constant power supply to the stator winding by varying a PWM duty ratio of the switching signal. apparatus.   The motor control means is configured to energize a predetermined phase of the stator winding and rotate the permanent magnet rotor to a predetermined rotational position before forcibly rotating the permanent magnet rotor. The brushless motor control device according to claim 1, wherein the control device is a brushless motor control device.   The motor control means increases the rotational speed of the permanent magnet rotor by gradually shortening the period of energizing the stator winding while forcibly rotating the permanent magnet rotor. The brushless motor control device according to any one of claims 1 to 3, wherein the brushless motor control device is provided.   The motor control means generates an induced voltage induced in the stator winding when the rotation speed of the permanent magnet rotor exceeds a predetermined value by forcibly rotating the permanent magnet rotor. 5. The brushless motor according to claim 1, wherein the permanent magnet rotor is rotated in a sensorless manner by sequentially switching a driving magnetic field of the stator windings based on the magnetic field. Control device. A fan motor consisting of a brushless motor;
A fan that rotates as the fan motor rotates;
A controller for driving the fan motor;
In a vehicle fan motor device comprising: a vehicle power supply battery that supplies power to the controller;
A fan motor device for a vehicle, wherein the controller of the brushless motor according to any one of claims 1 to 5 is used for the controller. A method for controlling a brushless motor comprising a stator having a stator winding for generating a driving magnetic field, and a rotor having a permanent magnet and rotating by a driving magnetic field generated from the stator winding,
An initial position step of energizing a predetermined phase of the stator winding to rotate the permanent magnet rotor to a predetermined rotational position;
Based on the synchronization signal, a driving magnetic field is sequentially generated in the stator winding to forcibly rotate the permanent magnet rotor, and the power supplied from the power supply device is detected and supplied to the stator winding. A forced drive step to keep the power supply to be constant,
When the rotational speed of the permanent magnet rotor exceeds a predetermined value by forcibly rotating the permanent magnet rotor, the stator winding is based on an induced voltage induced in the stator winding. A sensorless driving step of sequentially switching the driving magnetic field of the line to rotate the permanent magnet rotor in a sensorless manner;
A method for controlling a brushless motor, comprising:

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