JP2020018151A - Motor controller - Google Patents

Abstract

To provide a motor controller capable of accurately correcting the rotational position of a rotor detected by a Hall sensor, while rotating the motor smoothly.SOLUTION: A micro computer 32 brings coils of all phases into non-energization, when the rotational speed of a started motor 52 reaches an angle correction rotational speed, and a sensor signal correction amount calculation part 72 calculates a correction amount of the rotational position of a rotor 12 detected by a Hall sensor 12B on the basis of the rotational position of the rotor based on the induction voltages of a U-phase coil 14U, a V-phase coil 14V and a W-phase coil 14W, detected by an induction voltage detector 70. The micro computer 32 controls an inverter circuit 40 to generate such a voltage as having a phase corresponding to the rotational position corrected by the calculated correction value, and rotating the motor 52 at a target rotational speed matched to the current actual rotational speed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a motor control device.

  2. Description of the Related Art A drive device of a brushless DC motor (hereinafter, abbreviated as "motor") used for a blower motor or the like of a vehicle air conditioner is an inverter circuit using a FET (field effect transistor) as a switching element with a phase voltage corresponding to a rotor position. And the generated voltage is applied to the coil of the motor.

  In detecting the position of the rotor, the magnetic field of the rotor or a sensor magnet provided coaxially with the shaft of the motor for detecting the position of the rotor is detected by a Hall sensor using a Hall element which is a semiconductor. However, if the mounting position of the Hall sensor is displaced, the position of the rotor cannot be accurately detected, and the rotation of the motor becomes irregular.

  Patent Document 1 discloses that a position of a rotor is calculated based on an induced voltage generated in each coil in a non-energized state after power supply to each coil of a motor is stopped for a predetermined time, and a Hall sensor is calculated based on the calculated position of the rotor. Discloses an invention of a control device for a permanent magnet synchronous motor that corrects the position of a rotor detected by the controller.

JP-A-9-47066

  FIG. 9 is a schematic diagram showing an example of a change in rotation speed after starting a motor in a control device of a permanent magnet type synchronous motor described in Patent Document 1. In FIG. 9, after the motor is started, the actual rotation speed 102 of the motor is increased to the angle correction rotation speed in the first acceleration stage 104. Then, when the actual rotation speed 102 reaches the angle correction rotation speed, the switch provided between the inverter circuit and the motor is turned off, or the FET of the inverter circuit is turned off to stop energizing the coil of the motor. Then, the process proceeds to the angle correction step 106 for idling the motor.

  In the angle correction step 106, the induced voltage generated in the coil of each phase that has been de-energized is detected, the rotor position is calculated based on the detected induced voltage, and the rotor position detected using the Hall sensor is detected. Is calculated. Then, the correction amount of the rotor position detected by the Hall sensor is calculated.

  In the second acceleration stage 108 of FIG. 9, the rotor position detected by the Hall sensor is corrected based on the correction amount calculated in the angle correction stage 106, and the FET of the inverter circuit is operated to generate a voltage to be applied to the coil of the motor. Then, the actual rotation speed 102 is increased to the target rotation speed 100.

  However, in the control device of the permanent magnet type synchronous motor described in Patent Document 1, the actual rotation speed 102 is reduced by the motor being de-energized and idling in the angle correction stage 106, and as a result, the actual rotation speed 102 is reduced. And the speed difference between the target rotation speed 100 that is constant as described above and the angle correction rotation speed tends to increase.

  If control is performed to bring the actual rotation speed 102 close to the target rotation speed 100 in a state where the actual rotation speed 102 is greatly reduced with respect to the target rotation speed 100, the rotation of the motor is rapidly accelerated, which is temporary. However, as shown in FIG. 9, there is a problem that the actual rotation speed 102 hunts largely, and as a result, the motor startup noise becomes loud.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a motor control device capable of accurately correcting a rotational position of a rotor detected by a Hall sensor while smoothly rotating a motor. .

  In order to solve the problem, the motor control device according to claim 1 detects a magnetic field of a magnet attached to a rotating shaft of a rotor of the three-phase motor, and detects a rotor of the three-phase motor based on the detected magnetic field. A magnetic field rotational position detecting unit that detects the rotational position and actual rotational speed of the three-phase motor, and an induced voltage that detects the rotational position of the rotor of the three-phase motor based on an induced voltage generated in a coil of a non-energized phase of the three-phase motor. A rotation position detection unit, an inverter circuit that generates a voltage to be applied to each phase coil of the three-phase motor, and a rotation position detected by the magnetic field rotation position detection unit, and a rotation position detected by the induced voltage rotation position detection unit. A calculating unit for calculating a correction value for equalizing the position, and controlling the inverter circuit so that a voltage for increasing the actual rotation speed is supplied to the three-phase motor when the three-phase motor is started. When the rotation speed of the three-phase motor reaches a predetermined rotation speed, the controller controls the inverter circuit so as to turn off the energization of all the three-phase coils to idle the rotor. The arithmetic unit is controlled to calculate the correction value based on the rotation position detected by the induced voltage rotation position detection unit with the generated induced voltage, and when the arithmetic unit calculates the correction value, A voltage having a phase corresponding to the rotation position obtained by correcting the rotation position detected by the magnetic field rotation position detection unit with the correction value, and rotating the three-phase motor at a target rotation speed that matches the current actual rotation speed; And a control unit that controls the inverter circuit to generate

  According to this motor control device, the rotation position of the rotor detected based on the magnetic field of the rotor is determined by the rotation position of the rotor detected based on the induced voltage generated by stopping the power supply to the motor and causing the rotor to idle. After calculating the correction value to be corrected, the target rotation speed is made to coincide with the current actual rotation speed when the energization is restarted, thereby preventing sudden acceleration of the motor. As a result, it is possible to accurately correct the rotational position of the rotor detected by the Hall sensor while rotating the motor smoothly.

  The motor control device according to claim 2 is the motor control device according to claim 1, wherein the control unit starts supplying a voltage in a state where the target rotation speed matches the current actual rotation speed. Setting the target rotation speed to the predetermined rotation speed, and generating a voltage for rotating the three-phase motor so as to eliminate a deviation between the set target rotation speed and the actual rotation speed; When the predetermined rotation speed is reached, the inverter generates a voltage for rotating the three-phase motor so as to eliminate a deviation between the target rotation speed input from a higher-level control device and the actual rotation speed. Control the circuit.

  After the energization is resumed, the target rotation speed is switched to the predetermined rotation speed, which is the target rotation speed before the energization is stopped.However, the feedback control that eliminates the deviation between the target rotation speed and the actual rotation speed causes the motor to rapidly accelerate after the energization is resumed. This prevents the motor from rotating smoothly.

  According to a third aspect of the present invention, in the motor control apparatus according to the first or second aspect, the deviation between the target rotation speed and the actual rotation speed is eliminated by proportional (P) control and proportional integral (PI) control. And proportional integral derivative (PID) control.

  This motor control device uses one of proportional (P) control, proportional integral (PI) control, and proportional integral derivative (PID) control for feedback control for eliminating a deviation between a target rotational speed and an actual rotational speed. In addition, it is possible to prevent the motor from suddenly accelerating after re-energization, and to smoothly rotate the motor.

  The motor control device according to claim 4 is the motor control device according to any one of claims 1 to 3, wherein the calculation unit executes the calculation of the correction value in each phase a predetermined number of times, and The control unit calculates the average value of the calculated correction values, and corrects the rotation position of the rotor detected by the magnetic field rotation position detection unit with the average value of the correction values in each phase.

  According to this motor control device, the average value of the correction values of the rotational position of the rotor calculated a plurality of times is used for correcting the rotational position of the rotor, so that the rotational position of the rotor detected by the Hall sensor is accurately corrected. be able to.

It is a schematic diagram showing the composition of the motor unit using the motor control device concerning an embodiment of the invention. It is a figure showing the outline of the motor control device concerning an embodiment of the invention. In the motor control device according to the embodiment of the present invention, the terminal voltage of each phase when the motor is rotating at the angle correction rotation speed, an example of each of the position signal based on the induced voltage and the Hall sensor signal on the same time axis. It is the figure which contrasted. FIG. 4 is a schematic diagram illustrating an example of a change in rotation speed after starting the motor in the motor control device according to the embodiment of the present invention. 5 is a flowchart illustrating an example of control of the rotation speed of the motor in the motor control device according to the embodiment of the present invention. 5 is a flowchart illustrating an example of an angle correction process of the motor control device according to the embodiment of the present invention. 9 is a flowchart illustrating an example of control of a rotation speed of a motor in a motor control device according to a modification of the embodiment of the present invention. FIG. 11 is a schematic diagram showing an example of a change in rotation speed after starting a motor in a motor control device according to a modification of the embodiment of the present invention. It is the schematic which showed an example of the rotation speed change after the motor start in a brushless motor control apparatus.

[First Embodiment]
FIG. 1 is a schematic diagram showing a configuration of a motor unit 10 using a motor control device 20 according to the present embodiment. The motor unit 10 according to the present embodiment shown in FIG. 1 is a so-called blower motor unit used as an example for blowing air from a vehicle air conditioner.

  Motor unit 10 according to the present embodiment relates to a three-phase motor having an outer rotor structure in which rotor 12 is provided outside stator 14. The stator 14 is an electromagnet in which a conductive wire is wound around a core member, and constitutes three phases of a U phase, a V phase, and a W phase. Each of the U-phase, V-phase, and W-phase of the stator 14 generates a so-called rotating magnetic field by switching the polarity of the magnetic field generated by the electromagnet under the control of the motor control device 20 described later.

  A rotor magnet is provided inside the rotor 12 (not shown), and the rotor magnet rotates the rotor 12 by corresponding to a rotating magnetic field generated by the stator 14. The rotor 12 is provided with a shaft 16 and rotates integrally with the rotor 12. Although not shown in FIG. 1, in the present embodiment, a multi-blade fan such as a so-called sirocco fan is provided on the shaft 16, and the multi-blade fan rotates together with the shaft 16, so that air blowing in the vehicle air conditioner is reduced. It becomes possible.

  Stator 14 is attached to motor control device 20 via upper case 18. The motor control device 20 includes a substrate 22 of the motor control device 20, and a heat sink 24 that dissipates heat generated from elements on the substrate 22. The lower case 60 is attached to the motor unit 10 including the rotor 12, the stator 14, and the motor control device 20.

  FIG. 2 is a diagram schematically illustrating the motor control device 20 according to the present embodiment. The inverter circuit 40 switches the power supplied to the coils of the stator 14 of the motor 52. For example, the inverter FETs 44A and 44D perform switching of power supplied to the U-phase coil 14U, the inverter FETs 44B and 44E perform switching of power supplied to the V-phase coil 14V, and the inverter FETs 44C and 44F perform switching of power supplied to the W-phase coil 14W.

  The drains of the inverter FETs 44A, 44B, 44C are connected to the positive electrode of a vehicle-mounted battery 80 via a noise removing choke coil 46. The sources of the inverter FETs 44D, 44E, and 44F are connected to the negative electrode of the battery 80 via the reverse connection prevention FET 48.

  In the present embodiment, the Hall sensor 12B detects the magnetic field of the rotor magnet 12A or the sensor magnet provided coaxially with the shaft 16 as the magnetic field indicating the rotational position of the rotor 12. The microcomputer 32 detects the rotation speed and the position (rotation position) of the rotor 12 based on the magnetic field detected by the Hall sensor 12B, and controls the switching of the inverter circuit 40 according to the rotation speed and the rotation position of the rotor 12. .

  A control signal including a speed command value related to the rotation speed of the rotor 12 is input to the microcomputer 32 from an air conditioner ECU 82 which is a higher-level control device for the microcomputer 32 and controls the air conditioner in response to a switch operation of the air conditioner. Further, the microcomputer 32 is connected with a voltage dividing circuit 54 composed of a thermistor 54A and a resistor 54B, and a current detecting unit 56 provided between the inverter circuit 40 and the negative electrode of the battery 80.

  Since the resistance of the thermistor 54A constituting the voltage dividing circuit 54 changes in accordance with the temperature of the circuit board 22, the voltage of the signal output from the voltage dividing circuit 54 changes in accordance with the temperature of the circuit board 22. The microcomputer 32 calculates the temperature of the substrate 22 based on a change in the voltage of the signal output from the voltage dividing circuit 54.

  The current detection unit 56 includes a shunt resistor 56A having a resistance of about 0.2 mΩ to several Ω and an amplifier 56B that amplifies a potential difference between both ends of the shunt resistor 56A and outputs a voltage value proportional to the current of the shunt resistor 56A as a signal. And the signal output from the amplifier 56B is input to the temperature protection control unit 62 of the microcomputer 32. Temperature protection controller 62 calculates the current of inverter circuit 40 based on the signal output from amplifier 56B.

  In the present embodiment, the signal from the voltage dividing circuit 54 including the thermistor 54A, the signal output from the current detection unit 56, and the signal output from the Hall sensor 12B are input to the temperature protection control unit 62 in the microcomputer 32. . The temperature protection control unit 62 calculates the temperature of the element on the substrate 22, the current of the inverter circuit 40, the rotation speed of the rotor 12, and the like based on the input signals. A battery 80 as a power supply is connected to the temperature protection control unit 62, and the temperature protection control unit 62 detects the voltage of the battery 80 as a power supply voltage value.

  A control signal from the air conditioner ECU 82 is input to a speed control unit 64 in the microcomputer 32. The signal output from the Hall sensor 12B is also input to the speed control unit 64. The speed control unit 64 performs PWM (Pulse Width Modulation) control related to switching control of the inverter circuit 40 based on a control signal from the air conditioner ECU 82 and a rotation speed and a rotation position of the rotor 12 based on a signal from the hall sensor 12B. Calculate the duty ratio.

  A signal indicating the duty ratio calculated by the speed control unit 64 is input to the PWM output unit 66 and the temperature protection control unit 62. The temperature protection control unit 62 corrects the duty ratio calculated by the speed control unit 64 based on the temperature of the element on the substrate 22, the rotation speed of the rotor 12, and the load of the motor 52 and the circuit of the motor control device 20. Then, feedback is provided to the speed control unit 64. The load of the motor and the circuit is, for example, the current of the inverter circuit 40, the power supply voltage, or the duty ratio of the voltage generated by the inverter circuit 40. In the present embodiment, the duty ratio of the voltage generated by the inverter circuit 40 is the same as the duty ratio of the voltage generated by the inverter circuit 40 by the PWM output unit 66. As shown in FIG. 2, the signal indicating the duty ratio of the voltage generated by the PWM output unit 66 in the inverter circuit 40 is also input to the temperature protection control unit 62.

  Further, a memory 68 as a storage device is connected to the temperature protection control unit 62. The memory 68 stores a limit value for limiting the duty ratio when the motor 52 and the circuit are overloaded.

  The speed control unit 64 feeds back the correction by the temperature protection control unit 62 to the duty ratio calculated by itself, for example, by PI control or the like, and outputs a signal indicating the duty ratio for which the feedback was performed to the PWM output unit 66. The PWM output unit 66 controls switching of the inverter circuit 40 so as to generate a voltage having a duty ratio indicated by the input signal.

  In the present embodiment, an induced voltage detection that detects an induced voltage generated in each of the U-phase coil 14U, the V-phase coil 14V, and the W-phase coil 14W and outputs a position signal of the rotor 12 calculated based on the detected induced voltage. A section 70 is provided.

  In the present embodiment, the Hall sensor 12B compares the position signal of the rotor 12 detected by the Hall sensor 12B with the position signal of the rotor 12 calculated based on the induced voltage by the induced voltage detector 70. And a sensor signal correction amount calculation unit 72 for calculating the correction amount of the position signal of the rotor 12. The correction amount calculated by the sensor signal correction amount calculation unit 72 is input to the speed control unit 64 described above. The speed control unit 64 calculates the duty ratio by correcting the signal from the Hall sensor 12B with the correction amount described above.

  FIG. 3 shows an example of each of the terminal voltage of each phase, the position signal based on the induced voltage, and the Hall sensor signal when the motor 52 is rotating at the angle correction rotation speed in the motor control device 20 according to the present embodiment. It is the figure compared on the same time axis. The time axis in FIG. 3 is represented by an electrical angle.

  The induced voltage detector 70 detects the U-phase terminal voltage 110U, the V-phase terminal voltage 110V, and the W-phase terminal voltage 110W shown in FIG. The U-phase terminal voltage 110U, the V-phase terminal voltage 110V, and the W-phase terminal voltage 110W have a non-conducting section 116 where no voltage is applied. In the non-conducting section 116, not a small rectangular wave shape by PWM control but a slope shape. The voltage is changing. The change in the voltage in the non-energized section 116 is based on the induced voltage.

  In the present embodiment, the voltage of non-energized section 116 is U-phase reference voltage 112U when U-phase terminal voltage 110U, V-phase reference voltage 112V when V-phase terminal voltage 110V, and W-phase terminal voltage. In the case of 110 W, a point at which the voltage reaches the W-phase reference voltage 112 W is defined as a zero cross point 114. In the present embodiment, the position of the rotor 12 is detected based on the zero cross point 114. The reference voltage of each phase is an intermediate value between the high level and the low level of the terminal voltage, and is not necessarily 0 V, but may be conceptually defined as 0 V. Is referred to as a zero cross point as described above.

  The position signal in FIG. 3 is obtained by extracting a terminal voltage of each phase shown in FIG. 3 as a high-level signal by a circuit such as a comparator in the induced voltage detection unit 70, which is higher than a reference voltage of each phase. In the position signal shown in FIG. 3, a rectangular wave having a duty ratio larger than that of the rectangular wave by the PWM control changes from a low level to a high level (hereinafter, referred to as “rising”) and from a high level to a low level. A point that changes (hereinafter, referred to as “falling”) can be extracted as the zero cross point 114.

  The reference voltage, which is a threshold for a circuit such as a comparator to extract a high-level signal, is a U-phase when the coils of each phase of the motor 52 are Y-connected (star-connected) as shown in FIG. The voltage at the neutral point 14N (FIG. 2) where the coil 14U, the V-phase coil 14V, and the W-phase coil 14W are connected to one point is adopted. If the coils of each phase of the motor 52 are delta-connected, the reference voltage is specifically determined through modeling using a computer and testing on an actual machine.

  FIG. 3 shows a U-phase Hall sensor signal 120U, a V-phase Hall sensor signal 120V, and a W-phase Hall sensor signal 120W. In the present embodiment, the position error of the Hall sensor 12B is calculated based on the above-described position signal of each phase and the Hall sensor signal of each phase. The calculation of the error is performed as follows as an example.

  First, in FIG. 3, the electrical angle 360 degrees time 124 is measured based on the W-phase Hall sensor signal 120W. The electrical angle 360 degrees time 124 is the time from when the Hall sensor signal falls to the next time the Hall sensor signal falls. Alternatively, the time from when the Hall sensor signal rises to when the Hall sensor signal rises next may be set as the electrical angle 360 degrees time 124.

Next, as described in the following equation (1), the measured electrical angle of 360 degrees time 124 is divided by 12 to calculate the ideal electrical angle of 30 degrees time 122.
Ideal electrical angle 30 degree time = electrical angle 360 degree time / 12/12 (1)

Next, as shown in the following equation (2), the actual electrical angle 30 degrees time 126 including the Hall sensor positional deviation error 128 is calculated.
Actual electrical angle 30 degree time = W phase zero cross point time-W phase Hall sensor signal fall time (2)

  In Expression (2), the fall time of the W-phase Hall sensor signal is the time when the fall of the W-phase Hall sensor signal 120W is detected immediately after the zero-cross point 114 is detected in the W-phase.

Then, the Hall sensor position deviation error 128 is calculated using the following equation (3).
Hall sensor displacement error = ideal electrical angle 30 degree time-actual electrical angle 30 degree time (3)

  In the present embodiment, the correction amount of the Hall sensor signal is determined based on the Hall sensor positional deviation error 128 calculated as described above. For example, if the Hall sensor displacement error 128 is a positive value, the Hall sensor signal needs to be retarded from the Hall sensor displacement error 128, and if the Hall sensor displacement error 128 is a negative value, the Hall sensor The signal needs to be advanced by the Hall sensor displacement error 128. Therefore, in the present embodiment, the correction amount to be added to the Hall sensor signal is the Hall sensor position shift error 128.

  In the present embodiment, the electrical angle 360 degree time 124 is measured, but the time from when the Hall sensor signal falls to the next rise of the Hall sensor signal, or when the Hall sensor signal rises The time from when the Hall sensor signal falls to the next time may be measured as an electrical angle of 180 degrees.

When the electrical angle 180 degree time is measured, the ideal electrical angle 30 degree time 122 is calculated by dividing the measured electrical angle 180 degree time by 6 as described in the following equation (4).
Ideal electrical angle 30 degree time = electrical angle 180 degree time / 6 (4)

  After calculating the ideal electrical angle 30 degree time 122 using the above equation (4), the Hall sensor position error 128 is calculated using the above equations (2) and (3). In the above description, the calculation of the Hall sensor positional deviation error 128 in the W phase has been described. However, the Hall sensor positional deviation errors in the U phase and the V phase can be calculated in the same manner, and a detailed description is omitted.

  FIG. 4 is a schematic diagram showing an example of a change in rotation speed after starting the motor in motor control device 20 according to the present embodiment. As shown in FIG. 4, the target rotation speed 100 is set to an angle correction rotation speed when the motor is started. In a first acceleration stage 104 shown in FIG. 4, the actual rotation speed 102 of the motor 52 is increased to an angle correction rotation speed that is the target rotation speed 100.

  When the actual rotation speed 102 of the motor 52 reaches the angle correction rotation speed, all the FETs of the inverter circuit 40 are turned off, and the process proceeds to an angle correction step 106 in which energization of the coil of the motor 52 is stopped. In the angle correction step 106, the rotor 12 is idled by stopping the power supply to the coil, and the target rotation speed 100 matches the current actual rotation speed 102 (hereinafter, abbreviated as “actual rotation speed 102”) of the rotor 12 that idles. Let it. The actual rotation speed 102 of the rotor 12 is detected by the Hall sensor 12B, and the microcomputer 32 sets the detected actual rotation speed 102 to the target rotation speed 100.

  In the angle correction step 106, in a state where the target rotation speed 100 is made to coincide with the actual rotation speed 102, the induced voltages generated in the coils of the U, V, and W phases are detected, and the rotor 12 is detected based on the detected induced voltages. , And the displacement of the position of the rotor 12 detected using the Hall sensor 12B is calculated for each of the U-phase, V-phase, and W-phase. Then, a correction amount for making the rotational position of the rotor 12 detected by the Hall sensor 12B equal to the rotational position of the rotor 12 calculated based on the induced voltage is calculated for each of the U, V, and W phases.

  In the second acceleration step 108 of FIG. 4, the rotor position detected by the Hall sensor 12B is corrected based on the correction amount calculated in the angle correction step 106. Then, in a state where the target rotation speed 100 is made to coincide with the actual actual rotation speed 102, the FET of the inverter circuit 40 is operated to start generating a voltage having a phase corresponding to the corrected rotor position. Is applied to the coil of the motor 52.

  If the difference between the target rotation speed 100 and the actual actual rotation speed 102 at the start of energization is large, the actual rotation speed 102 of the motor 52 is rapidly accelerated and hunting is likely to occur. When energization is resumed in a state where 100 is set to the actual actual rotation speed 102, sudden acceleration of the rotation speed of the motor 52 is prevented, and the hunting is suppressed. Since the target rotation speed 100 and the actual actual rotation speed 102 need to be matched at the time of restart of energization, the target rotation speed 100 is made to match the actual rotation speed 102 in the second acceleration stage 108 in FIG. Is also good. However, it may take some time for the process to match the target rotation speed 100 with the actual rotation speed 102. In the present embodiment, the target rotation speed 100 is made to coincide with the actual rotation speed 102 in the angle correction step 106 in order to surely resume power supply in a state where the target rotation speed 100 is made to match the actual rotation speed 102.

  After the power supply to the motor 52 is restarted, the target rotation speed 100 is made to coincide with the angle correction rotation speed that is the target rotation speed 100 at the time of startup, and the deviation between the target rotation speed 100 and the actual actual rotation speed 102 is eliminated. By changing the rotation speed of the motor 52, the actual rotation speed 102 follows the target rotation speed 100 at the time of starting. After the actual actual rotational speed 102 reaches the target rotational speed 100 at the time of startup, rotation control for causing the actual rotational speed 102 of the motor 52 to follow the target rotational speed 100 indicated by the control signal input from the air conditioner ECU 82 is started. .

  The process of causing the actual rotation speed 102 to follow the angle correction rotation speed in the second acceleration stage 108 is performed by a proportional control (Proportional Controller, hereinafter abbreviated as “P control”). In the second acceleration stage 108, the voltage applied to the coil of the motor 52 is changed in proportion to the deviation between the actual rotation speed 102 and the target rotation speed 100, ie, the angle correction rotation speed. For example, when accelerating the actual rotation speed 102 to the angle correction rotation speed, the inverter circuit 40 is controlled so as to generate a voltage whose duty ratio is increased in proportion to the deviation between the actual rotation speed 102 and the angle correction rotation speed. I do.

  The target rotation speed 100 is made equal to the actual rotation speed 102 to prevent the motor 52 from suddenly accelerating at the start of energization, and the actual rotation speed 102 is reduced in the second acceleration stage 108 by the P control. Although slight hunting is observed, the rotation speed is accelerated to the angle correction rotation speed more smoothly than the case shown in FIG.

  FIG. 5 is a flowchart illustrating an example of control of the rotation speed of the motor in the motor control device 20 according to the present embodiment. In step 500, the target rotation speed 100 is input. The target rotation speed 100 is an angle correction rotation speed as described above.

  In step 502, the rotation of the motor 52 is started. There are various methods for starting the rotation of the motor 52. For example, the position of the rotor 12 is detected by the Hall sensor 12B, and then a voltage corresponding to the rotor position is applied to the coils of each phase. Then, the rotation of the motor 52 is started by gradually increasing the voltage applied to the coils of each phase.

  In step 504, it is determined whether or not the actual rotation speed 102 of the motor 52 has reached the angle correction rotation speed that is the target rotation speed 100. If the actual rotation speed 102 has reached the angle correction rotation speed, the procedure is performed. Move to step 506. If the actual rotation speed 102 does not reach the angle correction rotation speed, the process waits until the actual rotation speed 102 reaches the angle correction rotation speed. Steps 500 to 504 correspond to the first acceleration step 104 shown in FIG.

  In step 506, all the FETs of the inverter circuit 40 are turned off, and the rotor 12 is idled. Then, in step 508, the target rotation speed 100 is made to match the actual rotation speed 102.

  In step 510, an angle correction process described later with reference to FIG. 6 is performed to calculate a correction amount of the Hall sensor position error.

  In step 512, it is determined whether or not the calculation of the correction amount of the Hall sensor position error has been completed. If the calculation of the correction amount has been completed, the procedure proceeds to step 514. If the calculation of the correction amount has not been completed, the procedure moves to step 508. Steps 506 to 512 correspond to the angle correction step 106 shown in FIG.

  In step 514, the rotor position detected by the Hall sensor 12B is corrected based on the correction amount calculated in step 510. Then, in a state where the target rotation speed 100 is made to coincide with the actual actual rotation speed 102, the FET of the inverter circuit 40 is operated to start generating a voltage having a phase corresponding to the corrected rotor position. Is applied to the coil of the motor 52.

  In step 516, the motor is adjusted so that the target rotation speed 100 is made to coincide with the angle correction rotation speed that is the target rotation speed 100 at the time of starting, and the deviation between the target rotation speed 100 and the actual actual rotation speed 102 is eliminated by the P control. The processing is ended by changing the rotation speed of 52 and causing the actual rotation speed 102 to follow the target rotation speed 100 at the time of startup. Steps 514 to 516 correspond to the second acceleration stage 108 shown in FIG. After the actual rotation speed 102 has caught up with the target rotation speed 100 at the time of startup, rotation control for causing the actual rotation speed 102 of the motor 52 to follow the target rotation speed 100 indicated by the control signal input from the air conditioner ECU 82 is started.

  FIG. 6 is a flowchart illustrating an example of the angle correction process of the motor control device 20 according to the present embodiment. In step 600, while the motor 52 is idling, the electrical angle 360 degrees time 124 shown in FIG. 3 is measured.

  In step 602, the ideal electrical angle 30 degree time 122 shown in FIG. 3 is calculated by using the electrical angle 360 degree time 124 and the above-described equation (1) while the motor 52 is idling. In step 604, the actual electrical angle 30 degrees time 126 shown in FIG. 3 is calculated using the equation (2) while the motor 52 is idling.

  In step 606, while the motor 52 is idling, the ideal electrical angle 30 degree time 122, the actual electrical angle 30 degree time 126, and the Hall sensor position deviation error 128 are calculated using the above equation (3). The amount of error correction is calculated based on the position error 128, and the process returns.

  Note that the angle correction process is executed for each of the U-phase, V-phase, and W-phase, and calculates the correction amount of the Hall sensor positional deviation error for each of the U-phase, V-phase, and W-phase. The calculation of the correction amount may be performed two or more times in each phase, or the average value of the correction amounts calculated a plurality of times may be used as the determined correction amount and used for correcting the Hall sensor signal.

  As described above, according to the present embodiment, in order to calculate the correction amount of the Hall sensor position deviation error 128, the power supply to the coils of each phase of the motor 52 is turned off, and the rotor 12 is idled. In this case, the target rotation speed 100 is made to coincide with the actual actual rotation speed 102 of the rotor 12. As a result, when the energization of the coils of each phase is resumed after the calculation of the correction amount, the deviation between the target rotation speed 100 and the actual actual rotation speed 102 does not exist theoretically, or even if it exists, the deviation is small. The behavior in which the motor 52 rapidly accelerates the rotation so that the actual rotation speed 102 matches the target rotation speed 100 is suppressed.

  After the energization is started, the actual rotation speed 102 is gradually made closer to the target rotation speed 100 by the P control, so that the rotation of the motor 52 is stabilized and the startup noise of the motor 52 can be suppressed.

  The above-described rotation control in the present embodiment can be realized by changing the software of the microcomputer 32. Therefore, a motor control that can accurately correct the rotational position of the rotor detected by the Hall sensor while smoothly rotating the motor at low cost without changing the hardware configuration of the existing motor control device. An apparatus can be provided.

[Modification of First Embodiment]
Subsequently, a modified example of the first embodiment will be described. This modification is different from the second acceleration stage 108 shown in FIG. 4 in that the actual rotation speed 102 of the motor 52 approaches the target rotation speed 100 using PI control (Proportional-Integral Controller) instead of P control. This is different from the first embodiment. However, since the PI control can be realized by changing the control method by software, the configuration of the motor control device 20 according to the present modification as hardware is the same as that of the first embodiment. Therefore, a detailed description of the configuration is omitted.

  FIG. 7 is a flowchart illustrating an example of control of the rotation speed of the motor in the motor control device 20 according to the modification of the present embodiment. The procedure from step 700 to step 706 in FIG. 7 is the same as the procedure from step 500 to step 506 in FIG. Steps 700 to 704 correspond to the first acceleration stage 104 shown in FIG.

  In step 708, the actual rotational speed 102 of the rotor 12 when all the FETs of the inverter circuit 40 are turned off is stored. The stored actual rotation speed 102 is used in integration control described later.

  In step 710, the target rotation speed 100 is made to match the actual rotation speed 102. Then, in step 712, the angle correction processing described above with reference to FIG. 6 is performed, and the correction amount of the Hall sensor position error is calculated.

  In step 714, it is determined whether or not the calculation of the correction amount of the Hall sensor positional deviation error has been completed. If the calculation of the correction amount has been completed, the procedure proceeds to step 716. If the calculation of the correction amount has not been completed, the procedure moves to step 710. The steps 706 to 714 correspond to the angle correction step 106 shown in FIG.

  In step 716, the rotor position detected by the Hall sensor 12B is corrected based on the correction amount calculated in step 712. Then, in a state where the target rotation speed 100 is made to coincide with the actual actual rotation speed 102, the FET of the inverter circuit 40 is operated to start generating a voltage having a phase corresponding to the corrected rotor position. Is applied to the coil of the motor 52.

  In step 718, the actual rotation speed 102 stored in step 708 is compared with the current actual actual rotation speed 102. In step 720, the integral gain, which is a constant that is multiplied by the integral term of the deviation between the actual rotational speed 102 and the target rotational speed 100, is calculated by using the actual rotational speed 102 acquired in step 718 by the actual rotational speed 102 stored in step 708. Calculate as the divided quotient. The larger the deviation between the actual rotation speed 102 when the energization is turned off stored in step 708 and the actual rotation speed 102 when the energization is restarted, the smaller the integral gain calculated in step 720 becomes.

  When the integral gain is large, the contribution of the integral control in the PI control increases and the deviation is corrected quickly. However, when the contribution of the integral control is excessive, the actual rotational speed 102 exceeds the target rotational speed 100 (overshoot). In some cases. In this modification, the larger the deviation between the actual rotation speed 102 at the time of energization OFF stored at step 708 and the actual rotation speed 102 at the time of restarting energization, the smaller the integral gain calculated at step 720 is, Problems such as the above-mentioned overshoot are suppressed.

  In step 722, the motor is controlled so that the target rotation speed 100 is made equal to the angle correction rotation speed that is the target rotation speed 100 at the time of starting, and the deviation between the target rotation speed 100 and the actual rotation speed 102 is eliminated by PI control. The processing is ended by changing the rotation speed of 52 and causing the actual rotation speed 102 to follow the target rotation speed 100 at the time of startup. The steps 716 to 722 correspond to the second acceleration stage 108 shown in FIG. After the actual rotation speed 102 catches up with the target rotation speed 100, rotation control for causing the actual rotation speed 102 of the motor 52 to follow the target rotation speed 100 indicated by the control signal input from the air conditioner ECU 82 is started.

  FIG. 8 is a schematic diagram illustrating an example of a change in rotation speed after starting the motor in the motor control device 20 according to the present modification. As shown in FIG. 8, in the second acceleration stage 108, no trouble such as hunting is observed, and the rotation is accelerated to the angle correction rotation speed more smoothly than in the case of FIG.

  As described above, in the present modification, the actual rotation speed 102 is gradually approached to the target rotation speed 100 by the PI control, so that the rotation of the motor 52 is more stable than in the case of only the P control, and the startup noise of the motor 52 is reduced. Can be suppressed. In addition to the PI control, the actual rotation speed 102 may be gradually approached to the target rotation speed 100 by PID control (Proportional-Integral-Differential Controller).

  The above-described rotation control in this modification can be realized by changing the software of the microcomputer 32. Therefore, a motor control that can accurately correct the rotational position of the rotor detected by the Hall sensor while smoothly rotating the motor at low cost without changing the hardware configuration of the existing motor control device. An apparatus can be provided.

Reference Signs List 10: motor unit, 12: rotor, 12A: rotor magnet, 12B: hall sensor, 14: stator, 14N neutral point, 14U: U-phase coil, 14V: V-phase coil, 14W: W-phase coil, 16: shaft, 18 upper case, 20 motor controller, 22 board, 24 heat sink, 32 microcomputer, 40 inverter circuit, 44A, 44B, 44C, 44D, 44E, 44F inverter FET, 46 choke coil, 48 Reverse connection prevention FET, 52 motor, 54 voltage divider circuit, 54A thermistor, 54B resistor, 56 current detector, 56A shunt resistor, 56B amplifier, 60 lower case, 62 temperature protection controller, 64 ... Speed control unit, 66 ... PWM output unit, 68 ... Memory, 70 ... Induced voltage detection unit, 72 ... Sensor signal correction amount Outlet, 80: battery, 82: air conditioner ECU, 90: target rotation speed, 92: rotation speed, 94: first acceleration stage, 96: angle correction stage, 98: second acceleration stage, 100: target rotation speed, 102 ... Actual rotation speed, 104 ... First acceleration stage, 106 ... Angle correction stage, 108 ... Second acceleration stage, 110U ... U-phase terminal voltage, 110V ... V-phase terminal voltage, 110W ... W-phase terminal voltage, 112U ... U-phase Reference voltage, 112V: V-phase reference voltage, 112W: W-phase reference voltage, 114: Zero cross point, 116: No-current section, 120U: U-phase Hall sensor signal, 120V: V-phase Hall sensor signal, 120W: W-phase Hall sensor Signal, 122: ideal electrical angle of 30 degrees, 124: electrical angle of 360 degrees, 126: actual electrical angle of 30 degrees, 128: Hall sensor position error

Claims (4)

A magnetic field rotation position detection unit that detects a magnetic field of a magnet attached to a rotation shaft of a three-phase motor rotor, and detects a rotation position and an actual rotation speed of the three-phase motor rotor based on the detected magnetic field;
Based on an induced voltage generated in a coil of a non-energized phase of the three-phase motor, an induced voltage rotational position detecting unit that detects a rotational position of a rotor of the three-phase motor,
An inverter circuit that generates a voltage to be applied to each phase coil of the three-phase motor;
A calculation unit that calculates a correction value for making the rotation position detected by the magnetic field rotation position detection unit equal to the rotation position detected by the induced voltage rotation position detection unit.
At the time of starting the three-phase motor, the inverter circuit is controlled so that a voltage for increasing the actual rotation speed is supplied to the three-phase motor, and when the rotation speed of the three-phase motor reaches a predetermined rotation speed, Controlling the inverter circuit so as to turn off the energization of all three phases of coils, causing the rotor to idle, and the rotational position detected by the induced voltage rotational position detection unit with an induced voltage generated during the idle rotation of the rotor. Controlling the calculation unit to calculate the correction value based on the correction value, and when the calculation unit calculates the correction value, the rotation position detected by the magnetic field rotation position detection unit is corrected by the correction value. A control unit that has a phase corresponding to a rotation position, and controls the inverter circuit to generate a voltage that rotates the three-phase motor at a target rotation speed that matches the current actual rotation speed.
A motor control device including:   The control unit sets the target rotation speed to the predetermined rotation speed after the start of voltage supply in a state where the target rotation speed matches the current actual rotation speed, and sets the target rotation speed to the target rotation speed. A voltage for rotating the three-phase motor so as to eliminate a deviation between the speed and the actual rotation speed, and when the actual rotation speed reaches the predetermined rotation speed, a target input from a higher-level control device. The motor control device according to claim 1, wherein the inverter circuit is controlled to generate a voltage for rotating the three-phase motor so as to eliminate a deviation between a rotation speed and the actual rotation speed.   3. The motor control according to claim 1, wherein the deviation between the target rotation speed and the actual rotation speed is eliminated by using one of proportional (P) control, proportional integral (PI) control, and proportional integral derivative (PID) control. 4. apparatus. The calculation unit, in each phase, while performing the calculation of the correction value a predetermined number of times, calculates an average value of the correction value calculated a predetermined number of times,
4. The motor control device according to claim 1, wherein the control unit corrects the rotation position of the rotor detected by the magnetic field rotation position detection unit using an average value of correction values in each phase. 5.