JP2008029122A - Controller of sensorless brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller of a sensorless brushless motor which controls deterioration of the number of rotations, and can speedily restore the motor in a normal state when a position of a magnet rotor cannot be detected. <P>SOLUTION: A pump controller 30 is provided with a sensorless signal circuit 36 for driving a pump motor 19, a driving signal generating circuit 37, an inverter part 31, a rotor position detecting circuit 32 detecting a rotation position of the magnet rotor 20, a rotation number detecting circuit 33 detecting the number of rotations of the magnet rotor 20, and an abnormality detecting circuit 35 detecting whether abnormality occurs or not based on a detection signal from the rotor position detecting circuit 32. When abnormality is not detected by the abnormality detecting circuit 35; conduction timing to respective phase coils 21 to 23 is switched in accordance with a detection result of the rotor position detecting circuit 32, and the pump motor 19 is driven without a sensor. When abnormality is detected by the abnormality detecting circuit 35, the pump motor 19 is compulsorily driven by the prescribed number of rotations. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device for controlling a sensorless brushless motor including a magnet rotor and a multi-phase armature coil. More specifically, the present invention relates to a sensorless brushless motor control device capable of suppressing a decrease in the number of rotations and quickly returning to a normal state when the position of the magnet rotor cannot be detected.

  Brushless motors that are suitable for long-term driving without friction consumption due to the absence of brushes and commutators are widely used as on-vehicle motors (cooling water pumps, fuel pumps, etc.), for example. Among such brushless motors, there is a sensorless motor (sensorless brushless motor) that is driven without using a sensor. In this sensorless brushless motor, the induced voltage generated in the three-phase armature coil on the stator core side is measured to detect the rotational position of the magnet rotor, determine the energization timing to the three-phase armature coil, and perform sensorless drive. Is going. In general, the rotational position detection detects the position of the magnet rotor by detecting the zero cross point of the generated electromotive force.

  However, in sensorless driving, noise may occur in the detected position signal, and the rotation cycle may change abruptly due to load fluctuations. In such a case, since a correct rotation position and rotation cycle cannot be detected, an appropriate drive signal cannot be sent, and sensorless drive will step out. And when sensorless drive stepped out, the motor was stopped once and then started again, but this caused a problem that it took a very long time to return to the normal state (sensorless drive state). It was.

  In order to solve this problem, in Patent Document 1, when an abnormality occurs in the rotational position information (sensorless driving is out of step), this is determined by the abnormality determining means, and the armature coil is detected by the rotational drive stopping means. The rotation of the magnet rotor is stopped by stopping the generation of the rotating magnetic field, rotating the magnet rotor by inertia, and detecting the rotational position information again from the induced electromotive force by the inertia rotation of the magnet rotor by the redrive control means. It has been proposed to resume stable sensorless driving by accurately detecting the position and regenerating a rotating magnetic field in the armature coil based on this rotational position information. In other words, according to the technique described in Patent Document 1, it is possible to return to the normal state (sensorless drive state) without stopping the rotation of the magnet rotor when an abnormality occurs.

JP 2005-57922 A

  However, in the technique described in Patent Document 1, when detection of the rotor position becomes impossible, energization to all phases of the armature coil is turned off, and the magnet rotor is rotated by inertia, which occurs at that time. After detecting the position of the magnet rotor again from the induced electromotive force, the energization to each phase of the armature coil is resumed. For this reason, there has been a problem that a delay time occurs because the rotational speed of the motor decreases before the motor returns to a normal state (sensorless driving state).

  Accordingly, the present invention has been made to solve the above-described problems, and when the position of the magnet rotor cannot be detected, the decrease in the rotational speed is suppressed and the normal state is quickly restored. It is an object of the present invention to provide a control device for a sensorless brushless motor that can be used.

  A control device for a sensorless brushless motor according to the present invention made to solve the above problems is a control device for controlling a sensorless brushless motor including a magnet rotor and a multi-phase armature coil. Drive means for driving a motor; rotor position detection means for detecting the rotational position of the magnet rotor based on an induced electromotive force generated in the armature coil; and rotation speed detection means for detecting the rotation speed of the magnet rotor; An abnormality detecting means for detecting whether or not an abnormality has occurred based on a detection signal from the rotor position detecting means, and the driving means detects the rotor when no abnormality is detected by the abnormality detecting means. Depending on the detection result of the position detection means, the energization timing to the armature coils of each phase is switched to detect the brushless motor. And less drive, when an abnormality is detected by the abnormality detecting means may be forced driving the brushless motor at a predetermined rotational speed.

In this sensorless brushless motor control device, the rotor position detecting means detects the rotational position of the magnet rotor based on the induced electromotive force generated in the armature coil. Then, the drive means switches the energization timing to the armature coils of each phase according to the detection result of the rotational position of the magnet rotor, and the brushless motor is driven sensorlessly.
Here, during the sensorless drive, noise may be generated in the position signal detected by the rotor position detecting means, or the rotation period of the magnet rotor may change abruptly due to a load change of the motor. In such a case, the waveform of the induced electromotive force generated in the armature coil has a pattern different from that in the normal state. Then, when the waveform pattern of the induced electromotive force at the normal time and the waveform pattern of the induced electromotive force from the rotor position detecting means are compared by the abnormality detection means, and a waveform pattern different from the waveform pattern at the normal time is detected It is detected that the rotational position of the magnet rotor has not been accurately detected, that is, an abnormality has occurred in the brushless motor.

When an abnormality is detected by the abnormality detecting means, the brushless motor is controlled by the driving means from the sensorless driving to the forced driving at a predetermined rotational speed. Specifically, for example, the brushless motor is forcibly driven at a rotational speed of about 60 to 80% of the rotational speed immediately before the occurrence of abnormality. That is, in the control device according to the present invention, the brushless motor is forcibly driven at a predetermined rotational speed without turning off the energization to all phases of the armature coil as in the technique described in Patent Document 1.
Thereby, it is possible to prevent a decrease in the rotational speed of the magnet rotor when an abnormality is detected, and to shorten the time until the motor returns to a normal state (sensorless driving state).

  Here, in the technique described in Patent Document 1, in order to return to normal when an abnormality is detected, the power to the brushless motor is turned off and then turned on again, resulting in motor noise and motor vibration. . On the other hand, in the control device according to the present invention, since the energization to the brushless motor is not turned off in order to return to normal when an abnormality is detected, it is possible to prevent the generation of motor noise and motor vibration. Can do.

  In the sensorless brushless motor control device according to the present invention, the drive means determines the predetermined rotational speed according to the rotational speed detected by the rotational speed detection means immediately before the abnormality detection means detects an abnormality. It is desirable to decide.

  As a result, when an abnormality is detected in the position detection of the magnet rotor, the brushless motor is forcibly driven at the number of revolutions determined according to the number of revolutions detected by the revolution number detection means immediately before that. The reduction can be suppressed and the normal state (brushless drive state) can be promptly restored.

  In the sensorless brushless motor control apparatus according to the present invention, the driving means may be configured to set the predetermined rotational speed to a rotational speed detected by the rotational speed detection means immediately before the abnormality detection means detects an abnormality. It is desirable that the rotation speed be 1/2 or more and larger than the rotational speed in forced driving at the time of startup.

  As a result, when an abnormality is detected in the position detection of the magnet rotor, the rotational speed is more than 1/2 of the rotational speed detected by the rotational speed detection means immediately before that and larger than the rotational speed in the forced drive at startup. The brushless motor is forcibly driven. For this reason, since it can prevent that the rotation speed of a magnet rotor becomes smaller than 1/2 of rotation speed just before abnormality detection, the fall of rotation speed can be suppressed reliably. In addition, since the rotational speed to be forcibly driven is larger than the rotational speed at startup, it is possible to reliably shorten the time until the motor returns to the normal state (sensorless driving state).

  In the sensorless brushless motor control apparatus according to the present invention, when the abnormality is detected by the abnormality detection means after the control means forcibly drives the brushless motor at the predetermined rotational speed, It is desirable to perform forced driving.

When an abnormality is detected by the abnormality detection means, usually, the rotational position of the magnet rotor cannot be detected due to a sudden change in the rotation period due to noise or load fluctuation. However, even when the brushless motor stops for some reason, the abnormality is detected by the abnormality detection means. In such a case, even if the brushless motor is forcibly driven at a predetermined rotational speed, it is difficult to restart it. If such a state continues, an extra load is applied to the brushless motor (power is supplied). There is a risk of damage.
If an abnormality is detected by the abnormality detection means even after the abnormality is detected by the abnormality detection means and the brushless motor is forcibly driven at a predetermined rotational speed, the brushless motor is likely to be stopped. Therefore, in such a situation, the forced drive at the predetermined rotation speed is stopped and the forced drive at start-up is performed to prevent the brushless motor from being damaged and surely return to the normal state (sensorless drive state). Can be made.

  According to the sensorless brushless motor control device of the present invention, as described above, when the position of the magnet rotor can no longer be detected, it is possible to quickly return to the normal state by suppressing the decrease in the rotational speed. it can.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a most preferred embodiment that embodies a control device for a sensorless brushless motor according to the present invention will be described in detail with reference to the drawings. In the present embodiment, the present invention is applied to an automobile fuel supply system. That is, in the present embodiment, the present invention is applied to a pump controller that controls a fuel pump including a sensorless brushless motor.

  The fuel supply system will be described with reference to FIG. FIG. 1 is a diagram showing a schematic configuration of a fuel supply system to which a control device of the present invention is applied. The fuel supply system 10 supplies fuel to injectors 11, 12, 13, and 14 provided in intake ports that lead to a combustion chamber of an engine (not shown). In the fuel supply system 10, fuel supplied from the fuel tank 15 to the injectors 11 to 14 via the fuel pump 16 and the fuel pipe 17 is injected and supplied to the intake port. The electric fuel pump 16 includes a pump motor 19 and is built in the fuel tank 15. The pump motor 19 is a sensorless brushless motor, and a U-phase coil 21, a V-phase coil 22, and a W-phase coil 23 are star-connected to the magnet rotor 20 (see FIG. 2). The fuel pump 16 pumps up the fuel stored in the fuel tank 15, discharges it to the fuel pipe 17, and pumps it to the injectors 11 to 14. The fuel pump 16 is provided with a fuel filter 18, and the fuel sucked into the fuel pump 16 is filtered by the fuel filter 18.

  Here, a pump controller 30 is connected to the fuel pump 16. The pump controller 30 controls the drive of the fuel pump 16 (pump motor 19), and controls the rotation speed of the pump motor 19 so as to achieve the target fuel pressure. Then, the drive control of the fuel pump 16 is performed by the pump controller 30, whereby the fuel in the fuel tank 15 passes through the fuel filter 18, the fuel pump 16, the fuel pipe 17, and the like to the injectors 11 to 14 at the target fuel pressure. Pumped. The fuel pressure-fed to the injector 14 is injected into the intake port as the injectors 11 to 14 are operated, forms a combustible air-fuel mixture with the intake air, and is taken into the combustion chamber.

  As shown in FIG. 2, the pump controller 30 includes an inverter unit 31, a rotor position detection circuit 32, a rotation speed detection circuit 33, a current value detection circuit 34, an abnormality detection circuit 35, and a sensorless drive signal circuit. 36 and a drive signal generation circuit 37 are provided. Here, the inverter unit 31, the sensorless drive signal circuit 36, and the drive signal generation circuit 37 correspond to the “drive means” of the present invention. FIG. 2 is a block diagram showing the configuration of the pump controller 30.

  The inverter unit 31 supplies drive power to the pump motor 19. A DC power supply 39 is connected to the inverter unit 31 and includes six transistors Tr1 to Tr6. In the inverter unit 31, the transistors Tr <b> 1 to Tr <b> 6 are switched at a predetermined timing based on the signal from the drive signal generation circuit 37, thereby controlling the rotational drive of the pump motor 19.

  The rotor position detection circuit 32 detects the rotational position of the magnet rotor 20. The rotor position detection circuit is connected to the U-phase coil 21, the V-phase coil 22, and the W-phase coil 23, detects the induced voltage generated in each phase, and magnet rotor 20 based on the detected timing of the induced voltage. Is detected (estimated). Specifically, the rotor position detection circuit 32 detects the rotational position of the magnet rotor 20 by detecting a zero cross point of the generated electromotive force. Then, the rotor position detection circuit 32 inputs the detected rotation position information to the rotation speed detection circuit 33 and the sensorless signal circuit 36.

  The rotation speed detection circuit 33 detects the rotation speed of the magnet rotor 20. The rotation speed detection circuit 33 is connected to the rotor position detection circuit 32 and detects the rotation speed of the magnet rotor 20 from the rotation position information detected by the rotor position detection circuit 32. The rotational speed detection circuit 33 inputs the detected rotational speed information and the rotational position information detected by the rotor position detection circuit 32 to the abnormality detection circuit 35.

  The current value detection circuit 34 detects a current value flowing through the pump motor 19. The current value detection circuit 34 is connected to the inverter unit 31 and detects a current value supplied to the pump motor 19 by a current detection resistor 38. Then, the current value detection circuit 34 inputs the detected current value to the abnormality detection circuit 35 and the sensorless signal circuit 36.

  The abnormality detection circuit 35 detects an abnormality of the pump motor 19 (the rotation position of the magnet rotor 20 can no longer be detected). In the abnormality detection circuit 35, the waveform pattern of the induced electromotive force in the normal state (see FIG. 3) is compared with the waveform pattern of the induced electromotive force from the rotor position detection circuit 32, and is different from the waveform pattern in the normal state. When the waveform pattern (see FIG. 4) is detected, that is, when the rotational position of the magnet rotor 20 cannot be detected, it is detected that an abnormality has occurred in the pump motor 19.

  Specifically, the normal waveform pattern of the induced electromotive force generated in the U-phase coil 21 of the pump motor 19 has a waveform as shown in FIG. On the other hand, for example, when the energization timing is delayed by 30 °, the waveform is as shown in FIG. FIG. 3 is a diagram showing a normal waveform pattern of the induced electromotive force generated in the U-phase coil. FIG. 4 is a diagram showing a waveform pattern when the induced electromotive force generated in the U-phase coil is abnormal (when the energization timing is delayed by 30 °).

In the energization of the U-phase coil 21, in the period (1), the transistor Tr1 is turned off and the transistor Tr2 is turned on. In the period (2), both the transistors Tr1 and Tr2 are turned off. In the period (3), the transistor Tr1 is turned on and the transistor Tr2 is turned off. In the period (4), both the transistors Tr1 and Tr2 are turned off. Thereafter, after the period (5), switching of the transistors Tr1 and Tr2 is repeatedly performed as in the periods (1) to (4). Then, during normal operation, as shown in FIG. 3, in the period (2) (6)..., A voltage value that is ½ of the voltage of the DC power supply 39 is straddled from the low voltage side to the high voltage side. The waveform has a voltage value that is ½ of the voltage of the power supply 39 from the high voltage side to the low voltage side. On the other hand, when the energization timing is delayed by 30 °, as shown in FIG. 4, in the periods (2), (4), (6). As described above, when an abnormality occurs in the pump motor 19, the waveform of the induced electromotive force generated in each phase coil 21 to 23 becomes a pattern different from the waveform at the normal time. Can be detected.
In the present embodiment, the abnormality detection circuit 35 takes into account the rotational speed of the magnet rotor 20 and the current value flowing through the pump motor 19 in addition to the waveform pattern of the induced electromotive force generated in each phase coil 21 to 23. An abnormality of the motor 19 is detected.

  The sensorless signal circuit 36 generates a sensorless signal for driving the pump motor 19. In the sensorless signal circuit 36, three types of sensorless signals are generated. That is, a signal for sensorless driving of the pump motor 19 (sensorless driving signal), a signal for performing forced driving at the time of abnormality (forced driving signal at abnormal time), and a signal for performing forced driving at startup (forced driving at startup) Signal) is generated. Specifically, a sensorless drive signal is generated based on the rotational position information from the rotor position detection circuit 32 until an abnormality signal is input from the abnormality detection circuit 35. When an abnormal signal is input from the abnormality detection circuit 35, an abnormal time forced drive signal is generated. Further, when the pump motor 19 is started, a forced driving signal at the time of starting is generated. Furthermore, in the present embodiment, since the detection result (current value) is input from the current value detection circuit 34 to the sensorless signal circuit 36, the sensorless signal circuit 36 performs a drive signal for performing constant current control as necessary. Can also be generated.

  The drive signal generation circuit 37 generates a signal for controlling the operation of the transistors Tr1 to Tr6 of the inverter unit 31. The drive signal generation circuit 37 generates an operation signal for the transistors Tr1 to Tr6 based on the sensorless signal input from the sensorless signal circuit 36, and controls the switching operation of the transistors Tr1 to Tr6.

  The pump controller 30 is connected to a controller (ECU) 40 that performs overall control of the engine. Various signals output from various sensors 41 such as an air flow meter are input to the controller 40. Then, the controller 40 controls the injectors 11 to 14 in order to execute fuel injection control based on these input signals. The fuel injection control is to control the fuel amount (fuel injection amount) injected from the injectors 11 to 14 and the injection timing thereof according to the operating state of the engine. Further, the controller 40 outputs control signals to various actuators 42 such as a throttle based on these input signals. Further, the controller 40 outputs a drive request / stop request for the fuel pump 16 to the pump controller 30.

  The controller 40 has a known configuration, that is, a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a backup RAM, an external input circuit, an external output circuit, and the like. The controller 40 constitutes a logical operation circuit formed by connecting a CPU, a ROM, a RAM, a backup RAM, an external input circuit, an external output circuit, and the like through a bus. The ROM stores in advance a predetermined control program related to control in the engine. The RAM temporarily stores the calculation result of the CPU. The backup RAM stores data stored in advance. The CPU executes various controls according to a predetermined control program based on detection values of various sensors input via an input circuit.

  Next, drive control of the fuel pump 16 (pump motor 19) by the pump controller 30 having the above-described configuration will be described with reference to FIG. FIG. 5 is a flowchart showing the processing contents of drive control of the fuel pump 16 (pump motor 19) by the pump controller 30.

  First, the pump controller 20 supplies power to the pump motor 19 in response to a drive request from the controller 40 to drive the pump motor 19, and stops supplying power to the pump motor 19 in response to a stop request from the controller 40. 19 is stopped. Specifically, when a drive request is input to the pump controller 20, the sensorless signal circuit 36 generates a forced drive signal at startup. Then, the drive signal generation circuit 37 generates operation control signals for the transistors Tr1 to Tr6 based on the forcible start-up drive signal input from the sensorless signal circuit 36, and the inverter unit 31 (transistors Tr1 to Tr6) is generated based on the operation control signal. ) Is activated, and the pump motor 19 is activated.

  Thereafter, the rotational position of the magnet rotor 20 is detected by the rotor position detection circuit 32, and a sensorless drive signal is generated by the sensorless signal circuit 36 based on the position detection information. The drive signal generation circuit 37 generates operation control signals for the transistors Tr1 to Tr6 based on the sensorless drive signal input from the sensorless signal circuit 36, and the inverter unit 31 (transistors Tr1 to Tr6) is generated by the operation control signal. In operation, the pump motor 19 is driven sensorlessly.

  Then, during sensorless driving, it is determined whether the rotational position of the magnet rotor 20 can be detected, in other words, whether an abnormality is detected by the abnormality detection circuit 35 (S1). If no abnormality is detected by the abnormality detection circuit 35 (S1: YES), the pump motor 19 is driven by normal control, that is, sensorless driving (S6).

  On the other hand, when an abnormality is detected by the abnormality detection circuit 35 (S1: NO), it is considered that the sensorless drive has stepped out, and therefore the pump motor 19 is driven by the abnormal-time forced drive control (S2). Specifically, the sensorless signal circuit 36 generates an abnormal-time forced drive signal for forcibly driving the pump motor at a predetermined rotational speed. Then, the drive signal generation circuit 37 generates an operation control signal for the transistors Tr1 to Tr6 based on the abnormal forced drive signal input from the sensorless signal circuit 36, and the inverter unit 31 (transistors Tr1 to Tr6) is generated by the operation control signal. The pump motor 19 is forcibly driven at a predetermined rotational speed. If the rotation position signal is noisy due to this forcible driving, or if the rotation cycle changes suddenly due to load fluctuations (if the pump motor 19 is rotating when an abnormality is detected), the rotation of the magnet rotor 20 The position can be detected.

  When the rotational position of the magnet rotor 20 is detected by the forced driving of S2, in other words, when no abnormality is detected by the abnormality detection circuit 35 (S3: YES), the pump motor 19 is driven by normal control, that is, sensorless driving ( S6). Therefore, the pump motor 19 can be returned to the normal state (sensorless drive state) without turning off the energization of the phase coils 21 to 23. As described above, when the abnormality is detected, the pump motor 19 is forcibly driven at a predetermined rotational speed without turning off the energization of the pump motor. Therefore, the rotational speed of the magnet rotor 20 can be prevented from being lowered, and the pump motor 19 is operating normally. The time until returning to the state (sensorless driving state) can be shortened. Further, since energization to the pump motor 19 is not turned off, generation of motor noise and motor vibration can be prevented.

  Here, the predetermined rotational speed for forcibly driving the pump motor 19 at the time of abnormality is more than 1/2 of the rotational speed detected by the rotational speed detection circuit 33 immediately before the abnormality detection, and the rotational speed for forced driving at the time of startup. Is also set larger. Therefore, at the time of abnormality, the rotational speed of the magnet rotor 20 does not become smaller than 1/2 of the rotational speed immediately before the abnormality detection, so that a decrease in the rotational speed can be reliably suppressed. In addition, since the rotational speed for forced driving is larger than the rotational speed at startup, the time until the pump motor 19 returns to the normal state (sensorless driving state) can be reliably shortened.

  On the other hand, if the pump motor 19 is stopped due to foreign matter being caught when an abnormality is detected, the pump motor 19 may not be returned to a normal state (sensorless drive state) by the process of S2. . Therefore, in such a case, the rotational position of the magnet rotor 20 is not detected even after the forced driving of S2, in other words, an abnormality is detected by the abnormality detection circuit 35 (S3: NO). The pump motor 19 is started (S4). Thereby, it can prevent that the pump motor 19 is damaged by continuing the process of S2, and can return to a normal state (sensorless drive state) reliably.

  Specifically, the sensorless signal circuit 36 generates a forcible start-up drive signal for forcibly driving the pump motor 19 at the start-up rotation speed. Then, the drive signal generation circuit 37 generates operation control signals for the transistors Tr1 to Tr6 based on the forcible start-up drive signal input from the sensorless signal circuit 36, and the inverter unit 31 (transistors Tr1 to Tr6) is generated based on the operation control signal. ) Is activated, and the pump motor 19 is forcibly driven at the starting rotational speed. By this forced driving at the time of starting, the rotational position of the magnet rotor 20 can be detected (S5: YES), and the pump motor 19 is driven by normal control, that is, sensorless driving (S6). Thus, even if the pump motor 19 is stopped when an abnormality is detected, the pump motor 19 can be reliably returned to the normal state (sensorless drive state).

  As described above in detail, in the pump controller 30 according to the present embodiment, the abnormality detection circuit 35 uses the waveform pattern of the induced electromotive force generated in each phase coil 21 to 23 in the normal state and the rotor position detection circuit 32. When the waveform pattern of the induced electromotive force in each of the detected phase coils 21 to 23 is compared and a waveform pattern different from the normal waveform pattern is detected, the rotational position of the magnet rotor 20 is accurately detected. In other words, it is detected that an abnormality has occurred in the pump motor 19. Then, the sensorless signal circuit 36, the drive signal generating circuit 37, and the inverter unit 31 are controlled by switching the pump motor 19 from the sensorless drive to the forced drive at the time of abnormality. That is, the pump motor 19 is forcibly driven at a rotational speed greater than or equal to 1/2 of the rotational speed detected by the rotational speed detection circuit 33 immediately before the abnormality detection and larger than the rotational speed in the forced driving at the time of startup. For this reason, since the rotation speed of the pump motor 19 does not become smaller than ½ of the rotation speed immediately before the abnormality detection, a decrease in the rotation speed can be reliably suppressed. In addition, since the rotational speed for forced driving is larger than the rotational speed at startup, the time until the pump motor 19 returns to the normal state (sensorless driving state) can be reliably shortened. Further, in the pump controller 30 according to the present embodiment, when the abnormality is detected, the power supply to the pump motor 19 is not turned off when returning to normal, so that the generation of motor noise and motor vibration is prevented. be able to.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the present invention is applied to drive control of the pump motor 19 provided in the fuel pump 16, but the present invention is driven by a sensorless brushless motor (for example, a pump motor provided in a water pump). Can be widely applied to control.

  In the embodiment described above, the rotation speed detection circuit 33 detects the rotation speed of the magnet rotor 20 from the position detection information detected by the rotor position detection circuit 32, but the magnet rotor is detected from the current flowing through the pump motor 19. The number of rotations of 20 can also be detected. This is because the rotational speed of the magnet rotor 20 is proportional to the current value supplied to the pump motor 19.

It is a figure which shows schematic structure of the fuel supply system to which the control apparatus of this invention is applied. It is a block diagram which shows the structure of a pump controller. It is a figure which shows the waveform pattern at the time of the normal of the induced electromotive force which generate | occur | produces with a U-phase coil. It is a figure which shows the waveform pattern in the time of the abnormality of the induced electromotive force which generate | occur | produces with a U-phase coil (when energization timing delays 30 degrees). It is a flowchart which shows the processing content of the drive control of the fuel pump (pump motor) by a pump controller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fuel supply system 11, 12, 13, 14 Injector 15 Fuel tank 16 Fuel pump 17 Fuel piping 19 Pump motor 20 Magnet rotor 21 U phase coil 22 V phase coil 23 W phase coil 30 Pump controller 31 Inverter part 32 Rotor position detection circuit 33 Rotational Speed Detection Circuit 35 Abnormality Detection Circuit 36 Sensorless Signal Circuit 37 Drive Signal Generation Circuit 39 DC Power Supply 40 Controller (ECU)

Claims (4)

In a control device for controlling a sensorless brushless motor having a magnet rotor and a multi-phase armature coil,
Drive means for driving the brushless motor;
Rotor position detecting means for detecting a rotational position of the magnet rotor based on an induced electromotive force generated in the armature coil;
A rotational speed detection means for detecting the rotational speed of the magnet rotor;
An abnormality detection means for detecting whether an abnormality has occurred based on a detection signal from the rotor position detection means;
The driving means includes
When no abnormality is detected by the abnormality detection means, the brushless motor is sensorlessly driven by switching the energization timing to the armature coils of each phase according to the detection result of the rotor position detection means,
2. A sensorless brushless motor control device, comprising: forcibly driving the brushless motor at a predetermined rotational speed when an abnormality is detected by the abnormality detecting means. In the control apparatus of the sensorless brushless motor according to claim 1,
The control unit for a sensorless brushless motor, wherein the driving unit determines the predetermined rotation number according to a rotation number detected by the rotation number detection unit immediately before the abnormality detection unit detects an abnormality. . In the control device for the sensorless brushless motor according to claim 2,
The driving means has the predetermined rotational speed equal to or more than ½ of the rotational speed detected by the rotational speed detecting means immediately before the abnormality detecting means detects an abnormality, and the rotational speed in forced driving at startup. A sensorless brushless motor control device characterized in that it is also enlarged. In the control device for any one of the sensorless brushless motors according to claim 1,
The control means forcibly drives the brushless motor at the predetermined number of revolutions, and then, when an abnormality is detected by the abnormality detection means, performs forced driving at start-up. apparatus.

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