JP2008312383A - Position detecting device for rotator and position detecting method of rotator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position detecting device for rotator which improves the detection accuracy of rotator position, while suppressing the number of magnetic sensors. <P>SOLUTION: In the position detecting device, a first comparator 1, to which first output voltage HUP and first inverted output voltage HUM which a first Hall element HU outputs, are inputted outputs a first position detection signal HUs. A second comparator 2, to which second output voltage HVP and second inverted output voltage HVM which a second Hall element HV outputs, are inputted outputs a second position detection signal HVs. A third comparator 3, to which first inverted output voltage HUM that the first Hall element HU outputs and second output voltage HVP that the second Hall element HV outputs are inputted, outputs a third position detection signal HWs. Thus, three position detection signals can be obtained from the two Hall elements, and the resolution is improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a position detection device that detects the position of a rotor of a motor.

  2. Description of the Related Art Conventionally, a brushless DC motor for a fan of an air conditioner detects the rotor position by detecting the magnetic flux of the rotor with three magnetic sensors, and based on the detected rotor position information, the stator winding Stable operation is enabled by controlling the energization to.

  By the way, from the viewpoint of cost reduction, it is required to reduce the number of sensors for position detection.

  However, when the number of sensors is reduced, it is difficult to obtain accurate position information of the rotor, and there is a drawback that instability of motor operation is likely to be caused.

Thus, a technique for stably driving a motor (Patent Document 1 (Patent No. 3484740)) has been proposed even if the number of sensors is reduced. However, there is a problem that a special sensor is required and control is complicated. there were.
Japanese Patent No. 3484740

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rotor position detection device capable of improving the detection accuracy of the rotor position without requiring a special sensor or complicated control while suppressing the number of magnetic sensors. There is.

In order to solve the above-described problems, a rotor position detection device according to the present invention detects a magnetic flux of a rotor and has a first output signal corresponding to the detected magnetic flux and a first output signal having a phase opposite to that of the first output signal. A first magnetic sensor that outputs an inverted output signal of 1;
A second magnetic sensor that detects a magnetic flux of the rotor and outputs a second output signal corresponding to the detected magnetic flux and a second inverted output signal having a phase opposite to that of the second output signal. ,
The first output signal and the second output signal are out of phase by a predetermined electrical angle,
A first comparator to which the first output signal and the first inverted output signal are input;
A second comparator to which the second output signal and the second inverted output signal are input;
And a third comparator to which the first inverted signal and the second inverted output signal or the first inverted output signal and the second output signal are input.

  According to this invention, the first comparator outputs the first position detection signal based on the first output signal and the first inverted output signal input from the first magnetic sensor. The second comparator outputs a second position detection signal based on the second output signal input from the second magnetic sensor and the second inverted output signal. The third comparator receives the first output signal input from the first magnetic sensor and the second inverted output signal input from the second magnetic sensor, or input from the first magnetic sensor. A third position detection signal is output based on the first inverted output signal and the second output signal input from the second magnetic sensor.

  Therefore, according to the present invention, the first to third position detection signals can be obtained from the signals output by the first and second magnetic sensors. Therefore, according to the present invention, it is possible to increase the number of position detection signals while suppressing the number of magnetic sensors and improve the detection accuracy of the rotor position without requiring a special sensor or complicated control. .

The rotor position detection device according to an embodiment detects a magnetic flux of the rotor and outputs a first output signal corresponding to the detected magnetic flux;
A second magnetic sensor for detecting a magnetic flux of the rotor and outputting a second output signal corresponding to the detected magnetic flux;
A third magnetic sensor that detects a magnetic flux of the rotor and outputs a third output signal corresponding to the detected magnetic flux;
The first, second, and third output signals are out of phase with each other,
A first comparator to which the first output signal and the second output signal are input;
A second comparator to which the second output signal and the third output signal are input;
The third output signal and a third comparator to which the first output signal is input.

  According to this embodiment, the first comparator outputs the first position detection signal based on the first and second output signals input from the first and second magnetic sensors, and the second comparator A second position detection signal is output based on the second and third output signals input from the second and third magnetic sensors. The third comparator outputs a third position detection signal based on the third and first output signals input from the third and first magnetic sensors.

  That is, according to this embodiment, each of the first to third comparators outputs the first to third position detection signals based on output signals from two different magnetic sensors. Therefore, according to this embodiment, when a phase shift of the output signals of the first to third magnetic sensors occurs due to displacement of the rotor or the like, the position is determined from the output signal and the inverted output signal of the same magnetic sensor. Compared with the case where the detection signal is generated, the phase shift amount of the position detection signal due to the phase shift of the output signal can be reduced. Therefore, according to this embodiment, when the phase shift of the output signal of the magnetic sensor occurs, it is possible to suppress the phase shift amount of the position detection signal and improve the position detection accuracy of the rotor.

In the rotor position detection device according to one embodiment, the first magnetic sensor outputs the first output signal and a first inverted output signal having a phase opposite to that of the first output signal,
The second magnetic sensor outputs the second output signal and a second inverted output signal having a phase opposite to that of the second output signal,
The third magnetic sensor outputs the third output signal and a third inverted output signal having a phase opposite to that of the third output signal,
The first, second, and third output signals are 120 ° out of phase with each other,
A fourth comparator to which the first output signal and the first inverted output signal are input;
A fifth comparator to which the second output signal and the second inverted output signal are input;
A sixth comparator to which the third output signal and the third inverted output signal are input;

  According to this embodiment, the first, second, and third output signals are 120 ° out of phase with each other. The first comparator outputs a first position detection signal based on the first and second output signals input from the first and second magnetic sensors. The second comparator outputs a second position detection signal based on the second and third output signals input from the second and third magnetic sensors. The third comparator outputs a third position detection signal based on the third and first output signals input from the third and first magnetic sensors.

  The fourth comparator outputs a fourth position detection signal based on the first output signal and the first inverted output signal. The fifth comparator outputs a fifth position detection signal based on the second output signal and the second inverted output signal. The sixth comparator outputs a sixth position detection signal based on the third output signal and the third inverted output signal.

  According to this embodiment, the position of the rotor can be detected with the resolution of the electrical angle of 30 ° by the first to sixth position detection signals. Further, by using the first to sixth position detection signals obtained in this embodiment, the motor can be driven and controlled by 120 ° energization and 150 ° energization.

  The rotor position detection device according to an embodiment includes the first, second, and third position detection signals output from the first, second, and third comparators, and the fourth, fifth, and fifth positions. The fourth, fifth, and sixth position detection signals output from the six comparators are input, and the first, second, and third position detection signals are output, but the fourth, fifth, and fifth position detection signals are output. The first state in which the position detection signal 6 is not output, and the second state in which the fourth, fifth, and sixth position detection signals are output but the first, second, and third position detection signals are not output. It has a switching part that can be switched to a state.

  According to this embodiment, each position detection signal can be advanced by an electrical angle of 30 ° by switching the switching unit from the first state to the second state. Moreover, each position detection signal can be delayed by an electrical angle of 30 ° by switching the switching unit from the second state to the first state. Thereby, since the position detection information of the rotor based on the position detection signal can be shifted, it is possible to control to shift the phase angle of the rotor. Therefore, for example, the phase angle of the rotor can be adjusted to two load points of high load or low load of the motor, and the efficiency of the motor can be improved.

  A motor driving apparatus according to an embodiment includes the rotor position detection device, and sets the switching unit to the first state and energizes a stator winding for driving the rotor by 150 °. And a control unit capable of performing a first energization control and a second energization control for setting the switching unit to the second state and energizing the stator winding by 120 °.

  According to this embodiment, the control unit performs the first energization control for 150 ° energization at a high load, while the second energization control for 120 ° energization with a switching loss smaller than the 150 ° energization is performed at a low load. Sometimes can be done. When the load is low, the ratio of the switching loss to the circuit loss is larger than the steady loss. Therefore, the control unit controls the fluctuation of the switching loss between the high load and the low load. , Improve efficiency.

  According to the rotor position detection device of the present invention, the first to third position detection signals can be obtained from the signals output from the first and second magnetic sensors. Therefore, according to the present invention, it is possible to increase the number of position detection signals while suppressing the number of magnetic sensors and improve the detection accuracy of the rotor position without requiring a special sensor or complicated control. .

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

(First embodiment)
FIG. 1 is a circuit diagram of a first embodiment of a rotor position detecting apparatus according to the present invention. The first embodiment includes a first Hall element HU as a first magnetic sensor, a second Hall element HV as a second magnetic sensor, and first to third comparators 1 to 3. In the first and second Hall elements HU, HV, one voltage terminal is connected to the power source of the power supply voltage Vcc via the resistor R1, and the other voltage terminal is connected to the ground via the resistor R2.

  The first Hall element HU has an output terminal connected to the non-inverting input terminal of the first comparator 1 and an inverting output terminal connected to the inverting input terminal of the first comparator 1. The first Hall element HU outputs the first output voltage HUP to the output terminal and outputs the first inverted output voltage HUM to the inverted output terminal according to the magnetic flux penetrating the first Hall element HU. . The first output voltage HUP and the first inverted output voltage are in opposite phases. The first output voltage HUP is a first output signal, and the first inverted output voltage HUM is a first inverted output signal.

  On the other hand, the second Hall element HV has an output terminal connected to the non-inverting input terminal of the second comparator 2 and an inverting output terminal connected to the inverting input terminal of the second comparator 2. The second Hall element HV outputs the second output voltage HVP to the output terminal and the second inverted output voltage HVM to the inverted output terminal in accordance with the magnetic flux penetrating the Hall element HV. The second output voltage HVP and the second output voltage are in opposite phases. The second output voltage HVP is a second output signal, and the second inverted output voltage HVM is a second inverted output signal.

  The third comparator 3 has a non-inverting input terminal connected to the inverting output terminal of the first Hall element HU, and an inverting input terminal connected to the output terminal of the second Hall element HV.

  The first Hall element HU is attached to, for example, a brushless DC motor having a structure shown in FIG. In FIG. 3, 31 is a shaft, 32 and 33 are bearings, 35 is a yoke, 36 is a magnet, 37 is a stator winding, 38 is a core, and 40 is a circuit board. The yoke 35 and the magnet 36 constitute a rotor 41, and the coil 37 and the core 38 constitute a stator 42. The first Hall element HU is attached to the circuit board 40. Although not shown in FIG. 3, the second Hall element HV outputs a second output voltage HVP whose phase is delayed by 120 ° compared to the first output voltage HUP of the first Hall element HU. As shown, the circuit board 40 is attached.

  Next, the upper column A of the waveform diagram of FIG. 2 shows the waveform of the first output voltage HUP output from the first Hall element HU as the HU-phase Hall element signal waveform input to the first comparator 1. The waveform of the 1st inversion output voltage HUM is shown. Further, as the HV phase Hall element signal waveform input to the second comparator 2, the waveform of the second output voltage HVP and the waveform of the second inverted output voltage HVM of the second Hall element HV are shown. The waveform of the second output voltage HVP of the second Hall element HV and the first inverted output voltage HUM of the first Hall element HU are used as the HW-phase Hall element signal waveform input to the third comparator 3. The waveform is shown. In the lower column B of the waveform diagram of FIG. 2, the signal waveform of the first position detection signal HUs output from the first comparator 1 and the signal of the second position detection signal HVs output from the second comparator 2 are displayed. The waveform and the signal waveform of the third position detection signal HWs output from the third comparator 3 are shown. In FIG. 2, the vertical axis represents amplitude and the horizontal axis represents electrical angle (phase).

According to the first embodiment, the first output voltage HUP, the first inverted output voltage HUM, the second output voltage HVP, the second output from the first and second Hall elements HU, HV are output. From the inverted output voltage HVM, first to third position detection signals HUs, HVs, and HWs are obtained. Therefore, according to the first embodiment, since the three position detection signals HUs, HVs, HWs can be obtained from the two Hall elements HU, HV, the number of position detection signals can be reduced while suppressing the number of magnetic sensors. As a result, the position detection accuracy of the rotor 41 can be improved without requiring a special sensor or complicated control. More specifically, with the two Hall elements HU and HV, the resolution when n = 2 is obtained in the following equation (1).
360 ° / (n (n + 1)) (1)

  Therefore, according to the above embodiment, the resolution for detecting the position of the stator 41 is 60 ° in electrical angle. On the other hand, in the conventional example in which two position detection signals are obtained from two Hall elements, the resolution is (360 ° / 2n) = 90 ° in electrical angle. Therefore, according to this embodiment, the resolution is 30 °. Can be improved.

  Therefore, this embodiment is effective for detecting the position of the rotor of a motor used under conditions with a lot of disturbances, for applications that require torque during startup, for applications that require reliable startup, and the like. In particular, this is effective for detecting the position of the rotor of a motor used in an outdoor unit of an air conditioner.

  In the first embodiment, the inverted output voltage HUM of the first Hall element HU is input to the non-inverting input terminal of the third comparator 3, while the output voltage HVP of the second Hall element HV is set to the third level. Although input to the non-inverting input terminal of the comparator 3, the output voltage HUP of the first Hall element HU is input to the inverting input terminal of the third comparator 3, while the inverted output voltage HVM of the second Hall element HV is 3 may be input to the non-inverting input terminal of the comparator 3. In the first embodiment, as shown in the waveform diagram of FIG. 2, the phase of the output voltage HUP of the first Hall element HU is 120 ° ahead of the phase of the output voltage HVP of the second Hall element HV. However, the phase difference between the output voltage HUP of the first Hall element HU and the output voltage HVP of the second Hall element HV is not limited to 120 °.

(Second embodiment)
Next, FIG. 4 shows a circuit diagram of a second embodiment of the rotor position detection apparatus of the present invention. The second embodiment includes a first Hall element HU1, a second Hall element HV1, a third Hall element HW1, and first to third comparators 11 to 13. The first, second, and third Hall elements HU1, HV1, and HW1 are first, second, and third magnetic sensors, respectively.

  Each of the first, second, and third Hall elements HU1, HV1, and HW1 has one voltage terminal connected to the power supply of the power supply voltage Vcc through the resistor R11 and the other voltage terminal connected through the resistor R12. Connected to ground.

  In the first comparator 11, the first output voltage HUP1 of the first Hall element HU1 is input to the non-inverting input terminal, and the second output voltage HVP1 of the second Hall element HV1 is input to the inverting input terminal. Entered. In the second comparator 12, the second output voltage HVP1 of the second Hall element HV1 is input to the non-inverting input terminal, and the third output voltage HWP1 of the third Hall element HW1 is input to the inverting input terminal. Is entered. The third comparator 13 receives the third output voltage HWP1 of the third Hall element HW1 at the non-inverting input terminal, and the first output voltage HUP1 of the first Hall element HU1 at the inverting input terminal. Is entered.

  In FIG. 4, HUM1, HVM1, and HWM1 are inverted output voltages as inverted output signals output from the first, second, and third Hall elements HU1, HV1, and HW1, respectively. The inverted output voltages HUM1, HVM1, and HWM1 are in opposite phases to the output voltages HUP1, HVP1, and HWP1, respectively.

  The first, second, and third Hall elements HU1, HV1, and HW1 are attached to, for example, a brushless DC motor having a structure shown in FIG. The first to third Hall elements HU1, HV1, and HW1 are attached to the circuit board 40 so as to output output voltages HUP1, HVP1, and HWP1 that are 120 ° out of phase with each other. As an example, the first, second, and third Hall elements HU1, HV1, and HW1 are attached to the circuit board 40 as shown in FIG.

  Next, in the upper column of the waveform diagram of FIG. 5, the waveform of the output voltage HVP1 of the second Hall element HV1, the waveform of the output voltage HUP1 of the first Hall element HU1, and the position where the first comparator 11 outputs. The waveform of detection signal HUs1 is shown. Further, in the middle column of the waveform diagram of FIG. 5, the waveform of the output voltage HVP1 of the second Hall element HV1, the waveform of the output voltage HWP1 of the third Hall element HW1, and the position detection output by the second comparator 12 are displayed. The waveform of signal HVs1 is shown. In the lower part of the waveform diagram of FIG. 5, the waveform of the output voltage HUP1 of the first Hall element HU1, the waveform of the output voltage HWP1 of the third Hall element HW1, and the position detection output by the third comparator 13 are displayed. The waveform of signal HWs1 is shown. In FIG. 5, the vertical axis represents amplitude, and the horizontal axis represents electrical angle (phase).

  Incidentally, the position detection signals HUs1, HVs1, and HWs1, which are pulse signals shown in FIG. 5, are advanced in phase by 30 ° compared to the position detection signals HU ′, HV ′, and HW ′ according to the conventional method shown in the upper column of FIG. 6A. . In FIG. 6A, the vertical axis represents amplitude and the horizontal axis represents electrical angle (phase).

  Here, in this conventional system, the output voltage HUP1 ′ and the inverted output voltage HUM1 ′ of the first Hall element HU1 ′ are input to the non-inverting input terminal and the inverting input terminal of the first comparator 11, respectively. The output voltage HVP1 ′ and the inverted output voltage HVM1 ′ of the second Hall element HV1 ′ are input to the non-inverting input terminal and the inverting input terminal of the second comparator 12, respectively, and the output voltage HWP1 of the third Hall element HW1 ′ is input. ', The inverted output voltage HWM1' is input to the non-inverting input terminal and the inverting input terminal of the third comparator 13, respectively. FIG. 12 shows output voltages HUP1 ′, HUM1 ′, position detection signal HU ′, output voltages HVP1 ′, HVM1 ′, position detection signal HV ′, and output voltages HWP1 ′, HWM1 ′, position detection in this conventional method. The waveform of signal HW 'is shown. In FIG. 12, the vertical axis represents amplitude and the horizontal axis represents electrical angle (phase).

  For this reason, in the second embodiment, the mounting positions of the three Hall elements HU1, HV1, and HW1 are set so that the position detection signals HUs1, HVs1, and HWs1 shown in the lower column of FIG. 6A are delayed by 30 ° in electrical angle. It is shifted from the arrangement position of the three Hall elements in the conventional system.

  Here, in the above-described conventional method, the mounting position of the second Hall element HV1 ′ is deviated from the prescribed position, and the phases of the output signals HVP1 ′ and HVM1 ′ of the second Hall element HV1 ′ are delayed by 30 °. Signal waveforms of the position detection signals HUs1 ′, HVs1 ′, and HWs1 ′ are shown in the upper column of FIG. 6B. 6B, the phase difference between the position detection signal HUs1 ′ and the position detection signal HVs1 ′ is 30 °, and the phase difference between the position detection signal HVs1 ′ and the position detection signal HWs1 ′ is 90. °, the phase difference between the position detection signal HWs1 ′ and the position detection signal HUs1 ′ is 60 °. That is, the phase difference between the position detection signals varies greatly.

  Incidentally, if the number of magnetic poles of the rotor 41 is n, the mounting position deviation of 1 ° mechanical angle corresponds to (n / 2) times the electrical angle, so the larger the number of magnetic poles n, the larger the electrical angle due to the mounting position deviation. Deviation increases. For example, in the case of an 8-pole motor, a mounting position shift of 1 ° in mechanical angle becomes a shift of 4 ° in electrical angle.

  On the other hand, in the second embodiment, the mounting position of the second Hall element HV1 deviates from a specified position (for example, in the direction of arrow Z in FIG. 10), and the output signals HVP1, HVM1 of the second Hall element HV1. 6 is delayed by 30 °, the signal waveforms of the position detection signals HUs1, HVs1, and HWs1 are as shown in the lower column of FIG. 6B. That is, the phase difference between the position detection signal HUs1 and the position detection signal HVs1 is 60 °, the phase difference between the position detection signal HVs1 and the position detection signal HWs1 is 75 °, and the position detection signal HWs1 and the position detection signal HUs1 The phase difference between is 45 °. Therefore, according to the second embodiment, it is possible to suppress variation in phase difference between the position detection signals when the mounting position of the Hall element is shifted as compared with the conventional method.

  That is, according to the second embodiment, when the phase shift of the output signal of the Hall element occurs, the amount of phase shift of the position detection signal is suppressed without requiring a special sensor or complicated control. The position detection accuracy of the rotor can be improved. Therefore, it is possible to reduce the vibration and noise caused by the mounting position shift of the Hall element.

  In the second embodiment, the phase difference between the output voltage HUP1 of the first Hall element HU1 and the output voltage HVP1 of the second Hall element HV1, the output voltage HVP1 of the second Hall element HV1 and the third Hall. Although the phase difference from the output voltage HWP1 of the element HW1 is 120 °, the phase difference is not limited to 120 °.

(Third embodiment)
Next, a third embodiment of the rotor position detection apparatus of the present invention will be described with reference to the circuit diagram of FIG. 7 and the waveform diagram of FIG. The third embodiment differs from the second embodiment described above in the following points (i) and (ii).

(i) The point provided with the 4th-6th comparators 14-16 in addition to the 1st-3rd comparators 11-13.
(ii) In the second embodiment described above, the mounting positions of the three Hall elements HU1, HV1, and HW1 so that the position detection signals HUs1, HVs1, and HWs1 shown in the lower column of FIG. 6A are delayed by 30 ° in electrical angle. Is shifted from the arrangement position of the three Hall elements in the conventional method, but in the third embodiment, the arrangement position of the Hall elements is not shifted.

  In the third embodiment, the first output voltage HUP1 and the first inverted output voltage HUM1 of the first Hall element HU1 are input to the non-inverting input terminal and the inverting input terminal of the fourth comparator 14, respectively. Further, the second output voltage HVP1 and the second inverted output voltage HVM1 of the second Hall element HV1 are input to the non-inverting input terminal and the inverting input terminal of the fifth comparator 15, respectively. Further, the third output voltage HWP1 and the third inverted output voltage HWM1 of the third Hall element HW1 are input to the non-inverting input terminal and the inverting input terminal of the sixth comparator 16, respectively.

  Therefore, in the third embodiment, as shown in the upper column of FIG. 8, the fourth comparator 14 outputs the fourth position detection signal HUs0, and the fifth comparator 15 outputs the fifth position detection signal HVs0. The sixth comparator 16 outputs a sixth position detection signal HWs0. Further, the first comparator 11 outputs the first position detection signal HUs1, the second comparator 12 outputs the second position detection signal HVs1, and the third comparator 13 outputs the third position detection signal HWs1. Output. 8 shows data values of the position detection signals HUs0, HVs0, HWs0 and HUs1, HVs1, HWs1. In FIG. 8, the vertical axis represents amplitude, and the horizontal axis represents electrical angle (phase).

  As shown in the upper waveform diagram of FIG. 8, the fourth position detection signal HUs0 is 120 ° ahead of the fifth position detection signal HVs0, and the fifth position detection signal HVs0 is the sixth position detection signal HVs0. The phase is 120 ° ahead of the position detection signal HWs0, and the sixth position detection signal HWs0 is 120 ° ahead of the phase of the fourth position detection signal HUs0.

  Further, the first position detection signal HUs1 has a phase advance of 120 ° with respect to the second position detection signal HVs1, and the second position detection signal HVs1 has a phase advance of 120 ° with respect to the third position detection signal HWs1. Therefore, the phase of the third position detection signal HWs1 is advanced by 120 ° with respect to the first position detection signal HUs1.

  According to the third embodiment, the first, second, third, fourth, fifth, and sixth position detection signals HUs1, HVs1, HWs1, HUs0, HVs0, and HWs0 have a resolution of an electrical angle of 30 °. Accordingly, the position of the rotor 41 can be detected. Therefore, according to the third embodiment, the position of the rotor can be detected without increasing the number of Hall elements, increasing the number of position detection signals, and requiring a special sensor or complicated control. The accuracy can be improved.

  Further, by using the first to sixth position detection signals obtained in this embodiment, the output signals U, V, W and the output signal X for driving control by 150 ° energization as shown in the lower part of FIG. , Y, Z can be obtained, and the brushless DC motor of FIG. 3 can be driven and controlled with 150 ° energization. For example, as shown in FIG. 11, the first output voltage HUP1, the first inverted output voltage HUM1, the second output voltage HVP1, the second inverted output voltage HVM1, and the like from the three Hall elements HU1, HV1, and HW1. The third output voltage HWP1 and the third inverted output voltage HWM1 are input to the comparator unit 71 including the first to sixth comparators 11-16. The first to sixth position detection signals HUs 1, HVs 1, HWs 1, HUs 0, HVs 0, HWs 0 output from the comparator 71 are input to the position estimation unit 72. The position estimation unit 72 detects the position signal modes 0 to 11 based on the table shown in the middle part of FIG. 8, and the logic unit 73 creates a signal corresponding to the detected position signal modes 0 to 11. In the driver unit 74, the signal input from the logic unit 73 is converted into a voltage for driving the transistors Q1 to Q6, and output from the control unit 75 as output signals U, V, W and output signals X, Y, Z. , Input to the transistors Q1 to Q6. Thereby, the transistors Q1 to Q6 are on / off controlled. That is, the output signals U, V, and W are input as control signals to the transistors Q1, Q3, and Q5, respectively, and the output signals X, Y, and Z are input as control signals to the transistors Q2, Q4, and Q6, respectively. . As a result, the drive coils Lu, Lv, and Lw can be energized 150 °. In FIG. 11, 77 is an AC power source, 78 is a rectifier, and 79 is a smoothing capacitor.

(Fourth embodiment)
Next, FIG. 9 shows a fourth embodiment of the rotor position detection apparatus of the present invention. The fourth embodiment differs from the third embodiment described above in that a switching unit 51 and a position estimation unit 52 are provided. Therefore, in the fourth embodiment, differences from the third embodiment will be mainly described.

  In the fourth embodiment, the first, second, and third position detection signals HUs 1, HVs 1, and HWs 1 output from the first, second, and third comparators 11, 12, and 13 are sent from the signal line 53. The signal is input to the contact 51B of the switching unit 51. On the other hand, the fourth, fifth, and sixth position detection signals HUs0, HVs0, and HWs0 output from the fourth, fifth, and sixth comparators 14, 15, and 16 are connected from the signal line 55 to the contact of the switching unit 51. It is input to 51A.

  The switching unit 51 connects the contact 51A shown in FIG. 9 to the output line 57, but does not connect the contact 51B to the output line 57, and connects the contact 51B to the output line 57 but outputs the contact 51A. Switching to the first switching state not connected to the line 57 is possible.

  In the first switching state, the switching unit 51 outputs the first, second, and third position detection signals HUs1, HVs1, and HWs1 to the output line 57, but the fourth, fifth, and sixth The position detection signals HUs0, HVs0, and HWs0 are not output. On the other hand, the switching unit 51 outputs the fourth, fifth, and sixth position detection signals HUs0, HVs0, and HWs0 to the output line 57 in the second switching state, but the first, second, and third The position detection signals HUs1, HVs1, and HWs1 are not output.

  Therefore, when the switching unit 51 is set to the second switching state, the position estimation unit 52 receives the fourth, fifth, and sixth position detection signals HUs0, HVs0, The position of the rotor 41 can be estimated by HWs0, and 120 ° energization control of the stator winding 37 can be performed.

  On the other hand, when the switching unit 51 is set to the first switching state, the position estimation unit 52 receives the first, second, and third position detection signals HUs1 and HVs1 with an advance angle of 30 ° input from the switching unit 51. , HWs1 makes it possible to estimate the position of the stator 41 and perform 120 ° energization control of the stator winding 37.

  Therefore, according to the fourth embodiment, by switching between the position estimation of the rotor 41 with the advance angle of 0 ° and the position estimation of the rotor with the advance angle of 30 ° according to the load point of the motor, the low load The estimated position of the rotor can be changed according to the two load points near and near the high load, and it is possible to cope with load fluctuations and improve efficiency.

(Fifth embodiment)
Next, a fifth embodiment as a motor driving apparatus of the present invention will be described. The fifth embodiment is different from the above-described fourth embodiment in that a switching control unit 58 shown in FIG. 9 is provided. Therefore, the fifth embodiment will mainly describe differences from the above-described fourth embodiment.

  In the fifth embodiment, the switching control unit 58 includes a first energization control for setting the switching unit 51 in the first switching state during energization of the stator winding 37, and the switching unit 51 as described above. It is possible to switch to the second energization control in the second switching state.

  Therefore, in the fifth embodiment, if the switching control unit 58 places the switching unit 51 in the second switching state, the fourth, fifth, and sixth position detection signals are sent from the switching unit 51 to the position estimating unit 52. HUs0, HVs0, and HWs0 are input, and the position estimating unit 52 can estimate the position of the rotor 41 at an advance angle of 0 °, and 120 ° energization control of the stator winding 37 can be performed.

  When the switching control unit 58 switches the switching unit 51 to the first switching state during the 120 ° energization control, the switching unit 51 transfers the first advance of 30 ° to the position estimation unit 52. , Second and third position detection signals HUs1, HVs1, and HWs1 are input, the position estimating unit 52 can estimate the position of the rotor 41 at an advance angle of 30 °, and 150 ° energization control of the stator winding 37 is performed. It becomes possible.

  Therefore, according to the fourth embodiment, the position estimation of the rotor 41 having the advance angle of 0 ° and the position estimation of the rotor having the advance angle of 30 ° can be switched according to the load point of the motor. Therefore, for example, 120 ° energization is performed in the vicinity of a low load, while 150 ° energization is performed in the vicinity of a high load, so that it is possible to cope with load fluctuations and improve efficiency.

  In the first to fifth embodiments, the magnetic sensor is a Hall element, but the magnetic sensor may be a Hall IC.

1 is a circuit diagram of a first embodiment of a rotor position detection device according to the present invention; FIG. It is a wave form diagram which shows each signal waveform in the said 1st Embodiment. It is typical sectional drawing which shows the structure of a brushless DC motor. It is a circuit diagram of 2nd Embodiment of the position detection apparatus of the rotor of this invention. It is a wave form diagram which shows each signal waveform in the said 2nd Embodiment. It is a wave form diagram which shows the waveform of position detection signal HU ', HV', HW 'by a conventional system, and the waveform of each position detection signal HUs1, HVs1, HWs1 by the said 2nd Embodiment. It is a wave form diagram which shows a waveform when the phase of position detection signal HV 'is delayed by 30 degrees in the conventional method, and a waveform when the phase of position detection signal HVs1 is delayed by 30 degrees in the second embodiment. It is a circuit diagram of 3rd Embodiment of the position detection apparatus of the rotor of this invention. It is a wave form diagram which shows each signal waveform in the said 3rd Embodiment. It is a circuit diagram of 4th, 5th embodiment of this invention. 3 is a diagram schematically showing an example of attachment of first, second, and third Hall elements HU1, HV1, and HW1 to a circuit board 40. FIG. It is a figure which shows the control part 75 and switching circuit for energizing drive coil Lu, Lv, Lw 150 degrees using the 1st-6th position detection signal obtained in the said 3rd Embodiment. It is a wave form diagram which shows each signal waveform in the said conventional system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 1st comparator 2,12 2nd comparator 3,13 3rd comparator 14 4th comparator 15 5th comparator 16 6th comparator 31 Shaft 32,33 Bearing 35 Yoke 36 Magnet 37 Stator winding Line 38 Core 40 Circuit board 41 Rotor 42 Stator 51 Switching unit 52 Position estimation unit 53, 55 Signal line 58 Switching control unit HU, HU1 First Hall element HV, HV1 Second Hall element HUP, HUP1 First Output voltage HUM, HUM1 First inverted output voltage HVP, HVP1 Second output voltage HVM, HVM1 Second inverted output voltage HUs, HUs1 First position detection signal HVs, HVs1 Second position detection signal HWs, HWs1 Position detection signal 3 HW1 3rd Hall element HWP1 3rd output voltage HWM1 3rd inversion Power voltage HUs0 fourth position detection signals HVs0 fifth position detection signal HWs0 sixth position detection signals of the

The present invention relates to a position detection device that detects the position of a rotor of a motor and a position detection method of the rotor .

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rotor position detection device and a rotor capable of improving the detection accuracy of the rotor position without requiring a special sensor or complicated control while suppressing the number of magnetic sensors. It is to provide a position detection method .

  The present invention relates to a position detection device that detects the position of a rotor of a motor and a position detection method of the rotor.

  2. Description of the Related Art Conventionally, a brushless DC motor for a fan of an air conditioner detects the rotor position by detecting the magnetic flux of the rotor with three magnetic sensors, and based on the detected rotor position information, the stator winding Stable operation is enabled by controlling the energization to.

  By the way, from the viewpoint of cost reduction, it is required to reduce the number of sensors for position detection.

  However, when the number of sensors is reduced, it is difficult to obtain accurate position information of the rotor, and there is a drawback that instability of motor operation is likely to be caused.

Thus, a technique for stably driving a motor (Patent Document 1 (Patent No. 3484740)) has been proposed even if the number of sensors is reduced. However, there is a problem that a special sensor is required and control is complicated. there were.
Japanese Patent No. 3484740

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rotor position detection device and a rotor capable of improving the detection accuracy of the rotor position without requiring a special sensor or complicated control while suppressing the number of magnetic sensors. It is to provide a position detection method.

In order to solve the above-described problem, a rotor position detection device according to a reference example of the present invention detects a magnetic flux of a rotor, and the first output signal corresponding to the detected magnetic flux and the first output signal are: A first magnetic sensor that outputs a first inverted output signal of opposite phase;
A second magnetic sensor that detects a magnetic flux of the rotor and outputs a second output signal corresponding to the detected magnetic flux and a second inverted output signal having a phase opposite to that of the second output signal. ,
The first output signal and the second output signal are out of phase by a predetermined electrical angle,
A first comparator to which the first output signal and the first inverted output signal are input;
A second comparator to which the second output signal and the second inverted output signal are input;
And a third comparator to which the first inverted signal and the second inverted output signal or the first inverted output signal and the second output signal are input.

According to this reference example , the first comparator outputs a first position detection signal based on the first output signal and the first inverted output signal input from the first magnetic sensor. The second comparator outputs a second position detection signal based on the second output signal input from the second magnetic sensor and the second inverted output signal. The third comparator receives the first output signal input from the first magnetic sensor and the second inverted output signal input from the second magnetic sensor, or input from the first magnetic sensor. A third position detection signal is output based on the first inverted output signal and the second output signal input from the second magnetic sensor.

Therefore, according to this reference example , the first to third position detection signals can be obtained from the signals output from the first and second magnetic sensors. Therefore, according to this reference example , while suppressing the number of magnetic sensors, the number of position detection signals can be increased, and the detection accuracy of the rotor position can be improved without requiring a special sensor or complicated control. I can plan.

Further, the rotor position detection device of the present invention detects a magnetic flux of the rotor and outputs a first output signal corresponding to the detected magnetic flux,
A second magnetic sensor for detecting a magnetic flux of the rotor and outputting a second output signal corresponding to the detected magnetic flux;
A third magnetic sensor that detects a magnetic flux of the rotor and outputs a third output signal corresponding to the detected magnetic flux;
The first, second, and third output signals are out of phase so that the position of the rotor can be detected ,
Further, a first comparator you outputting said first output signal and the first position detection signal a second output signal is input,
A second comparator you outputting said second output signal and the second position detection signal is the third output signal is input,
E Bei a third comparator you output the third output signal and the first output signal is inputted to the third position detection signal,
The position of the rotor is detected from a combination of signal levels of the first, second, and third position detection signals.

According to the present invention , the first comparator outputs the first position detection signal based on the first and second output signals input from the first and second magnetic sensors, and the second comparator The second position detection signal is output based on the second and third output signals input from the second and third magnetic sensors. The third comparator outputs a third position detection signal based on the third and first output signals input from the third and first magnetic sensors.

That is, according to the present invention , each of the first to third comparators outputs the first to third position detection signals based on the output signals from two different magnetic sensors. Therefore, according to the present invention, when a phase shift of the output signals of the first to third magnetic sensors occurs due to a displacement of the rotor or the like, the position is detected from the output signal and the inverted output signal of the same magnetic sensor. Compared with the case of generating a signal, the amount of phase shift of the position detection signal due to the phase shift of the output signal can be reduced. Therefore, according to this embodiment, when the phase shift of the output signal of the magnetic sensor occurs, it is possible to suppress the phase shift amount of the position detection signal and improve the position detection accuracy of the rotor.

In the rotor position detection device according to one embodiment, the first magnetic sensor outputs the first output signal and a first inverted output signal having a phase opposite to that of the first output signal,
The second magnetic sensor outputs the second output signal and a second inverted output signal having a phase opposite to that of the second output signal,
The third magnetic sensor outputs the third output signal and a third inverted output signal having a phase opposite to that of the third output signal,
The first, second, and third output signals are 120 ° out of phase with each other,
Further, a fourth comparator you outputting said first output signal and the first inverted output signal is input to the fourth position detection signals,
A fifth comparator you outputting said second output signal and the second inverted output signal is input to the fifth position detection signal,
A sixth comparator that receives the third output signal and the third inverted output signal (HWM1) and outputs a sixth position detection signal ;
The position of the rotor is detected from a combination of signal levels of the first to sixth position detection signals.

  According to this embodiment, the first, second, and third output signals are 120 ° out of phase with each other. The first comparator outputs a first position detection signal based on the first and second output signals input from the first and second magnetic sensors. The second comparator outputs a second position detection signal based on the second and third output signals input from the second and third magnetic sensors. The third comparator outputs a third position detection signal based on the third and first output signals input from the third and first magnetic sensors.

  The fourth comparator outputs a fourth position detection signal based on the first output signal and the first inverted output signal. The fifth comparator outputs a fifth position detection signal based on the second output signal and the second inverted output signal. The sixth comparator outputs a sixth position detection signal based on the third output signal and the third inverted output signal.

  According to this embodiment, the position of the rotor can be detected with the resolution of the electrical angle of 30 ° by the first to sixth position detection signals. Further, by using the first to sixth position detection signals obtained in this embodiment, the motor can be driven and controlled by 120 ° energization and 150 ° energization.

  The rotor position detection device according to an embodiment includes the first, second, and third position detection signals output from the first, second, and third comparators, and the fourth, fifth, and fifth positions. The fourth, fifth, and sixth position detection signals output from the six comparators are input, and the first, second, and third position detection signals are output, but the fourth, fifth, and fifth position detection signals are output. The first state in which the position detection signal 6 is not output, and the second state in which the fourth, fifth, and sixth position detection signals are output but the first, second, and third position detection signals are not output. It has a switching part that can be switched to a state.

  According to this embodiment, each position detection signal can be advanced by an electrical angle of 30 ° by switching the switching unit from the first state to the second state. Moreover, each position detection signal can be delayed by an electrical angle of 30 ° by switching the switching unit from the second state to the first state. Thereby, since the position detection information of the rotor based on the position detection signal can be shifted, it is possible to control to shift the phase angle of the rotor. Therefore, for example, the phase angle of the rotor can be adjusted to two load points of high load or low load of the motor, and the efficiency of the motor can be improved.

  A motor driving apparatus according to an embodiment includes the rotor position detection device, and sets the switching unit to the first state and energizes a stator winding for driving the rotor by 150 °. And a control unit capable of performing a first energization control and a second energization control for setting the switching unit to the second state and energizing the stator winding by 120 °.

  According to this embodiment, the control unit performs the first energization control for 150 ° energization at a high load, while the second energization control for 120 ° energization with a switching loss smaller than the 150 ° energization is performed at a low load. Sometimes can be done. When the load is low, the ratio of the switching loss to the circuit loss is larger than the steady loss. Therefore, the control unit controls the fluctuation of the switching loss between the high load and the low load. , Improve efficiency.

  According to the rotor position detection device of the present invention, the first to third position detection signals can be obtained from the signals output from the first and second magnetic sensors. Therefore, according to the present invention, it is possible to increase the number of position detection signals while suppressing the number of magnetic sensors and improve the detection accuracy of the rotor position without requiring a special sensor or complicated control. .

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

( Reference example )
FIG. 1 is a circuit diagram of a reference example of a rotor position detecting apparatus according to the present invention. This reference example includes a first Hall element HU as a first magnetic sensor, a second Hall element HV as a second magnetic sensor, and first to third comparators 1 to 3. In the first and second Hall elements HU, HV, one voltage terminal is connected to the power source of the power supply voltage Vcc via the resistor R1, and the other voltage terminal is connected to the ground via the resistor R2.

  The first Hall element HU has an output terminal connected to the non-inverting input terminal of the first comparator 1 and an inverting output terminal connected to the inverting input terminal of the first comparator 1. The first Hall element HU outputs the first output voltage HUP to the output terminal and outputs the first inverted output voltage HUM to the inverted output terminal according to the magnetic flux penetrating the first Hall element HU. . The first output voltage HUP and the first inverted output voltage are in opposite phases. The first output voltage HUP is a first output signal, and the first inverted output voltage HUM is a first inverted output signal.

  On the other hand, the second Hall element HV has an output terminal connected to the non-inverting input terminal of the second comparator 2 and an inverting output terminal connected to the inverting input terminal of the second comparator 2. The second Hall element HV outputs the second output voltage HVP to the output terminal and the second inverted output voltage HVM to the inverted output terminal in accordance with the magnetic flux penetrating the Hall element HV. The second output voltage HVP and the second output voltage are in opposite phases. The second output voltage HVP is a second output signal, and the second inverted output voltage HVM is a second inverted output signal.

  The third comparator 3 has a non-inverting input terminal connected to the inverting output terminal of the first Hall element HU, and an inverting input terminal connected to the output terminal of the second Hall element HV.

  The first Hall element HU is attached to, for example, a brushless DC motor having a structure shown in FIG. In FIG. 3, 31 is a shaft, 32 and 33 are bearings, 35 is a yoke, 36 is a magnet, 37 is a stator winding, 38 is a core, and 40 is a circuit board. The yoke 35 and the magnet 36 constitute a rotor 41, and the coil 37 and the core 38 constitute a stator 42. The first Hall element HU is attached to the circuit board 40. Although not shown in FIG. 3, the second Hall element HV outputs a second output voltage HVP whose phase is delayed by 120 ° compared to the first output voltage HUP of the first Hall element HU. As shown, the circuit board 40 is attached.

  Next, the upper column A of the waveform diagram of FIG. 2 shows the waveform of the first output voltage HUP output from the first Hall element HU as the HU-phase Hall element signal waveform input to the first comparator 1. The waveform of the 1st inversion output voltage HUM is shown. Further, as the HV phase Hall element signal waveform input to the second comparator 2, the waveform of the second output voltage HVP and the waveform of the second inverted output voltage HVM of the second Hall element HV are shown. The waveform of the second output voltage HVP of the second Hall element HV and the first inverted output voltage HUM of the first Hall element HU are used as the HW-phase Hall element signal waveform input to the third comparator 3. The waveform is shown. In the lower column B of the waveform diagram of FIG. 2, the signal waveform of the first position detection signal HUs output from the first comparator 1 and the signal of the second position detection signal HVs output from the second comparator 2 are displayed. The waveform and the signal waveform of the third position detection signal HWs output from the third comparator 3 are shown. In FIG. 2, the vertical axis represents amplitude and the horizontal axis represents electrical angle (phase).

According to this reference example , the first output voltage HUP, the first inverted output voltage HUM, the second output voltage HVP, and the second inverted output output from the first and second Hall elements HU and HV. First to third position detection signals HUs, HVs, and HWs are obtained from the voltage HVM. Therefore, according to this reference example , three position detection signals HUs, HVs, and HWs can be obtained from the two Hall elements HU and HV, so that the number of position detection signals can be increased while suppressing the number of magnetic sensors. The position detection accuracy of the rotor 41 can be improved without requiring a special sensor or complicated control. More specifically, with the two Hall elements HU and HV, the resolution when n = 2 is obtained in the following equation (1).
360 ° / (n (n + 1)) (1)

Therefore, according to the above reference example , the resolution for detecting the position of the stator 41 is 60 ° in electrical angle. On the other hand, in the conventional example in which two position detection signals are obtained from two Hall elements, the resolution is (360 ° / 2n) = 90 ° in electrical angle. Therefore, according to this embodiment, the resolution is 30 °. It can be improved.

Therefore, this reference example is effective for detecting the position of the rotor of a motor used under conditions with a lot of disturbances, for applications that require torque during startup, for applications that require startup reliably, and the like. In particular, this is effective for detecting the position of the rotor of a motor used in an outdoor unit of an air conditioner.

In the above reference example , the inverted output voltage HUM of the first Hall element HU is input to the non-inverting input terminal of the third comparator 3, while the output voltage HVP of the second Hall element HV is input to the third comparator 3. The output voltage HUP of the first Hall element HU is input to the inverting input terminal of the third comparator 3, while the inverted output voltage HVM of the second Hall element HV is input to the third non-inverting input terminal. You may input into the non-inverting input terminal of the comparator 3. FIG. In the reference example , as shown in the waveform diagram of FIG. 2, the phase of the output voltage HUP of the first Hall element HU is 120 ° ahead of the phase of the output voltage HVP of the second Hall element HV. However, the phase difference between the output voltage HUP of the first Hall element HU and the output voltage HVP of the second Hall element HV is not limited to 120 °.

(First Embodiment)
Next, FIG. 4 shows a circuit diagram of a first embodiment of the rotor position detection apparatus of the present invention. The first embodiment includes a first Hall element HU1, a second Hall element HV1, a third Hall element HW1, and first to third comparators 11-13. The first, second, and third Hall elements HU1, HV1, and HW1 are first, second, and third magnetic sensors, respectively.

  Each of the first, second, and third Hall elements HU1, HV1, and HW1 has one voltage terminal connected to the power supply of the power supply voltage Vcc through the resistor R11 and the other voltage terminal connected through the resistor R12. Connected to ground.

  In the first comparator 11, the first output voltage HUP1 of the first Hall element HU1 is input to the non-inverting input terminal, and the second output voltage HVP1 of the second Hall element HV1 is input to the inverting input terminal. Entered. In the second comparator 12, the second output voltage HVP1 of the second Hall element HV1 is input to the non-inverting input terminal, and the third output voltage HWP1 of the third Hall element HW1 is input to the inverting input terminal. Is entered. The third comparator 13 receives the third output voltage HWP1 of the third Hall element HW1 at the non-inverting input terminal, and the first output voltage HUP1 of the first Hall element HU1 at the inverting input terminal. Is entered.

  In FIG. 4, HUM1, HVM1, and HWM1 are inverted output voltages as inverted output signals output from the first, second, and third Hall elements HU1, HV1, and HW1, respectively. The inverted output voltages HUM1, HVM1, and HWM1 are in opposite phases to the output voltages HUP1, HVP1, and HWP1, respectively.

  The first, second, and third Hall elements HU1, HV1, and HW1 are attached to, for example, a brushless DC motor having a structure shown in FIG. The first to third Hall elements HU1, HV1, and HW1 are attached to the circuit board 40 so as to output output voltages HUP1, HVP1, and HWP1 that are 120 ° out of phase with each other. As an example, the first, second, and third Hall elements HU1, HV1, and HW1 are attached to the circuit board 40 as shown in FIG.

  Next, in the upper column of the waveform diagram of FIG. 5, the waveform of the output voltage HVP1 of the second Hall element HV1, the waveform of the output voltage HUP1 of the first Hall element HU1, and the position where the first comparator 11 outputs. The waveform of detection signal HUs1 is shown. In the middle column of the waveform diagram of FIG. 5, the waveform of the output voltage HVP1 of the second Hall element HV1, the waveform of the output voltage HWP1 of the third Hall element HW1, and the position detection output by the second comparator 12 are displayed. The waveform of signal HVs1 is shown. In the lower part of the waveform diagram of FIG. 5, the waveform of the output voltage HUP1 of the first Hall element HU1, the waveform of the output voltage HWP1 of the third Hall element HW1, and the position detection output by the third comparator 13 are displayed. The waveform of signal HWs1 is shown. In FIG. 5, the vertical axis represents amplitude, and the horizontal axis represents electrical angle (phase).

  Incidentally, the position detection signals HUs1, HVs1, and HWs1, which are pulse signals shown in FIG. 5, are advanced in phase by 30 ° compared to the position detection signals HU ′, HV ′, and HW ′ according to the conventional method shown in the upper column of FIG. 6A. . In FIG. 6A, the vertical axis represents amplitude and the horizontal axis represents electrical angle (phase).

  Here, in this conventional system, the output voltage HUP1 ′ and the inverted output voltage HUM1 ′ of the first Hall element HU1 ′ are input to the non-inverting input terminal and the inverting input terminal of the first comparator 11, respectively. The output voltage HVP1 ′ and the inverted output voltage HVM1 ′ of the second Hall element HV1 ′ are input to the non-inverting input terminal and the inverting input terminal of the second comparator 12, respectively, and the output voltage HWP1 of the third Hall element HW1 ′ is input. ', The inverted output voltage HWM1' is input to the non-inverting input terminal and the inverting input terminal of the third comparator 13, respectively. FIG. 12 shows output voltages HUP1 ′, HUM1 ′, position detection signal HU ′, output voltages HVP1 ′, HVM1 ′, position detection signal HV ′, and output voltages HWP1 ′, HWM1 ′, position detection in this conventional method. The waveform of signal HW 'is shown. In FIG. 12, the vertical axis represents amplitude and the horizontal axis represents electrical angle (phase).

For this reason, in the first embodiment, the mounting positions of the three Hall elements HU1, HV1, and HW1 are set so that the position detection signals HUs1, HVs1, and HWs1 shown in the lower column of FIG. 6A are delayed by 30 degrees in electrical angle. It is shifted from the arrangement position of the three Hall elements in the conventional system.

  Here, in the above-described conventional method, the mounting position of the second Hall element HV1 ′ is deviated from the prescribed position, and the phases of the output signals HVP1 ′ and HVM1 ′ of the second Hall element HV1 ′ are delayed by 30 °. Signal waveforms of the position detection signals HUs1 ′, HVs1 ′, and HWs1 ′ are shown in the upper column of FIG. 6B. 6B, the phase difference between the position detection signal HUs1 ′ and the position detection signal HVs1 ′ is 30 °, and the phase difference between the position detection signal HVs1 ′ and the position detection signal HWs1 ′ is 90. °, the phase difference between the position detection signal HWs1 ′ and the position detection signal HUs1 ′ is 60 °. That is, the phase difference between the position detection signals varies greatly.

  Incidentally, if the number of magnetic poles of the rotor 41 is n, the mounting position deviation of 1 ° mechanical angle corresponds to (n / 2) times the electrical angle, so the larger the number of magnetic poles n, the larger the electrical angle due to the mounting position deviation. Deviation increases. For example, in the case of an 8-pole motor, a mounting position shift of 1 ° in mechanical angle becomes a shift of 4 ° in electrical angle.

On the other hand, in the first embodiment, the mounting position of the second Hall element HV1 deviates from the specified position (for example, in the direction of arrow Z in FIG. 10), and the output signals HVP1, HVM1 of the second Hall element HV1. 6 is delayed by 30 °, the signal waveforms of the position detection signals HUs1, HVs1, and HWs1 are as shown in the lower column of FIG. 6B. That is, the phase difference between the position detection signal HUs1 and the position detection signal HVs1 is 60 °, the phase difference between the position detection signal HVs1 and the position detection signal HWs1 is 75 °, and the position detection signal HWs1 and the position detection signal HUs1 The phase difference between is 45 °. Therefore, according to the first embodiment, it is possible to suppress variation in the phase difference between the position detection signals when the mounting position of the Hall element is shifted as compared with the conventional method.

That is, according to the first embodiment, when a phase shift of the output signal of the Hall element occurs, the amount of phase shift of the position detection signal is suppressed without requiring a special sensor or complicated control. The position detection accuracy of the rotor can be improved. Therefore, it is possible to reduce the vibration and noise caused by the mounting position shift of the Hall element.

In the first embodiment, the phase difference between the output voltage HUP1 of the first Hall element HU1 and the output voltage HVP1 of the second Hall element HV1, the output voltage HVP1 of the second Hall element HV1 and the third Hall. Although the phase difference from the output voltage HWP1 of the element HW1 is 120 °, the phase difference is not limited to 120 °.

(Second Embodiment)
Next, a second embodiment of the rotor position detection apparatus of the present invention will be described with reference to the circuit diagram of FIG. 7 and the waveform diagram of FIG. The second embodiment is different from the first embodiment in the following points (i) and (ii).

(i) The point provided with the 4th-6th comparators 14-16 in addition to the 1st-3rd comparators 11-13.
(ii) In the first embodiment described above, the mounting positions of the three Hall elements HU1, HV1, and HW1 so that the position detection signals HUs1, HVs1, and HWs1 shown in the lower column of FIG. 6A are delayed by 30 degrees in electrical angle. Is shifted from the arrangement positions of the three Hall elements in the conventional method, but in the second embodiment, the arrangement positions of the Hall elements are not shifted.

In the second embodiment, the first output voltage HUP1 and the first inverted output voltage HUM1 of the first Hall element HU1 are input to the non-inverting input terminal and the inverting input terminal of the fourth comparator 14, respectively. Further, the second output voltage HVP1 and the second inverted output voltage HVM1 of the second Hall element HV1 are input to the non-inverting input terminal and the inverting input terminal of the fifth comparator 15, respectively. Further, the third output voltage HWP1 and the third inverted output voltage HWM1 of the third Hall element HW1 are input to the non-inverting input terminal and the inverting input terminal of the sixth comparator 16, respectively.

Therefore, in the second embodiment, as shown in the upper column of FIG. 8, the fourth comparator 14 outputs the fourth position detection signal HUs0, and the fifth comparator 15 outputs the fifth position detection signal HVs0. The sixth comparator 16 outputs a sixth position detection signal HWs0. Further, the first comparator 11 outputs the first position detection signal HUs1, the second comparator 12 outputs the second position detection signal HVs1, and the third comparator 13 outputs the third position detection signal HWs1. Output. 8 shows data values of the position detection signals HUs0, HVs0, HWs0 and HUs1, HVs1, HWs1. In FIG. 8, the vertical axis represents amplitude, and the horizontal axis represents electrical angle (phase).

  As shown in the upper waveform diagram of FIG. 8, the fourth position detection signal HUs0 is 120 ° ahead of the fifth position detection signal HVs0, and the fifth position detection signal HVs0 is the sixth position detection signal HVs0. The phase is 120 ° ahead of the position detection signal HWs0, and the sixth position detection signal HWs0 is 120 ° ahead of the phase of the fourth position detection signal HUs0.

  Further, the first position detection signal HUs1 has a phase advance of 120 ° with respect to the second position detection signal HVs1, and the second position detection signal HVs1 has a phase advance of 120 ° with respect to the third position detection signal HWs1. Therefore, the phase of the third position detection signal HWs1 is advanced by 120 ° with respect to the first position detection signal HUs1.

According to the second embodiment, the first, second, third, fourth, fifth, and sixth position detection signals HUs1, HVs1, HWs1, HUs0, HVs0, and HWs0 have a resolution of an electrical angle of 30 °. Accordingly, the position of the rotor 41 can be detected. Therefore, according to the second embodiment, the position of the rotor can be detected without increasing the number of Hall elements, increasing the number of position detection signals, and requiring a special sensor or complicated control. The accuracy can be improved.

  Further, by using the first to sixth position detection signals obtained in this embodiment, the output signals U, V, W and the output signal X for driving control by 150 ° energization as shown in the lower part of FIG. , Y, Z can be obtained, and the brushless DC motor of FIG. 3 can be driven and controlled with 150 ° energization. For example, as shown in FIG. 11, the first output voltage HUP1, the first inverted output voltage HUM1, the second output voltage HVP1, the second inverted output voltage HVM1, The third output voltage HWP1 and the third inverted output voltage HWM1 are input to the comparator unit 71 including the first to sixth comparators 11-16. The first to sixth position detection signals HUs 1, HVs 1, HWs 1, HUs 0, HVs 0, HWs 0 output from the comparator 71 are input to the position estimation unit 72. The position estimation unit 72 detects position signal modes 0 to 11 based on the table shown in the middle part of FIG. 8, and the logic unit 73 creates a signal corresponding to the detected position signal modes 0 to 11. In the driver unit 74, the signal input from the logic unit 73 is converted into a voltage for driving the transistors Q1 to Q6, and output from the control unit 75 as output signals U, V, W and output signals X, Y, Z. , Input to the transistors Q1 to Q6. Thereby, the transistors Q1 to Q6 are on / off controlled. That is, the output signals U, V, and W are input as control signals to the transistors Q1, Q3, and Q5, respectively, and the output signals X, Y, and Z are input as control signals to the transistors Q2, Q4, and Q6, respectively. . As a result, the drive coils Lu, Lv, and Lw can be energized 150 °. In FIG. 11, 77 is an AC power source, 78 is a rectifier, and 79 is a smoothing capacitor.

( Third embodiment)
Next, FIG. 9 shows a third embodiment of the rotor position detection apparatus of the present invention. The third embodiment is different from the second embodiment described above in that a switching unit 51 and a position estimation unit 52 are provided. Therefore, in the third embodiment, differences from the second embodiment will be mainly described.

In the third embodiment, the first, second, and third position detection signals HUs 1, HVs 1, and HWs 1 output from the first, second, and third comparators 11, 12, and 13 are transmitted from the signal line 53. The signal is input to the contact 51B of the switching unit 51. On the other hand, the fourth, fifth, and sixth position detection signals HUs0, HVs0, and HWs0 output from the fourth, fifth, and sixth comparators 14, 15, and 16 are connected from the signal line 55 to the contact of the switching unit 51. It is input to 51A.

  The switching unit 51 connects the contact 51A shown in FIG. 9 to the output line 57, but does not connect the contact 51B to the output line 57, and connects the contact 51B to the output line 57 but outputs the contact 51A. Switching to the first switching state not connected to the line 57 is possible.

  In the first switching state, the switching unit 51 outputs the first, second, and third position detection signals HUs1, HVs1, and HWs1 to the output line 57, but the fourth, fifth, and sixth The position detection signals HUs0, HVs0, and HWs0 are not output. On the other hand, the switching unit 51 outputs the fourth, fifth, and sixth position detection signals HUs0, HVs0, and HWs0 to the output line 57 in the second switching state, but the first, second, and third The position detection signals HUs1, HVs1, and HWs1 are not output.

  Therefore, when the switching unit 51 is set to the second switching state, the position estimation unit 52 receives the fourth, fifth, and sixth position detection signals HUs0, HVs0, The position of the rotor 41 can be estimated by HWs0, and 120 ° energization control of the stator winding 37 can be performed.

  On the other hand, when the switching unit 51 is set to the first switching state, the position estimation unit 52 receives the first, second, and third position detection signals HUs1 and HVs1 with an advance angle of 30 ° input from the switching unit 51. , HWs1 makes it possible to estimate the position of the stator 41 and perform 120 ° energization control of the stator winding 37.

Therefore, according to the third embodiment, the load estimation of the rotor 41 with the advance angle of 0 ° and the position estimate of the rotor with the advance angle of 30 ° are switched according to the load point of the motor. The estimated position of the rotor can be changed according to the two load points near and near the high load, and it is possible to cope with load fluctuations and improve efficiency.

( Fourth embodiment)
Next, a description will be given of a fourth embodiment as a motor driving apparatus of the present invention. The fourth embodiment differs from the third embodiment described above in that it includes a switching control unit 58 shown in FIG. Therefore, this 4th Embodiment mainly demonstrates a different point from the above-mentioned 3rd Embodiment.

In the fourth embodiment, the switching control unit 58 includes a first energization control for setting the switching unit 51 in the first switching state during energization of the stator winding 37, and the switching unit 51 as described above. It is possible to switch to the second energization control in the second switching state.

Therefore, in the fourth embodiment, if the switching control unit 58 places the switching unit 51 in the second switching state, the fourth, fifth, and sixth position detection signals are sent from the switching unit 51 to the position estimating unit 52. HUs0, HVs0, and HWs0 are input, and the position estimating unit 52 can estimate the position of the rotor 41 at an advance angle of 0 °, and 120 ° energization control of the stator winding 37 can be performed.

  When the switching control unit 58 switches the switching unit 51 to the first switching state during the 120 ° energization control, the switching unit 51 transfers the first advance of 30 ° to the position estimation unit 52. , Second and third position detection signals HUs1, HVs1, and HWs1 are input, the position estimating unit 52 can estimate the position of the rotor 41 at an advance angle of 30 °, and 150 ° energization control of the stator winding 37 is performed. It becomes possible.

  Therefore, according to the fourth embodiment, the position estimation of the rotor 41 having the advance angle of 0 ° and the position estimation of the rotor having the advance angle of 30 ° can be switched according to the load point of the motor. Therefore, for example, 120 ° energization is performed in the vicinity of a low load, while 150 ° energization is performed in the vicinity of a high load, so that it is possible to cope with load fluctuations and improve efficiency.

In the first to fourth embodiments, the magnetic sensor is a Hall element, but the magnetic sensor may be a Hall IC.

It is a circuit diagram of the reference example of the position detection apparatus of the rotor of this invention. It is a wave form diagram which shows each signal waveform in the said reference example . It is typical sectional drawing which shows the structure of a brushless DC motor. 1 is a circuit diagram of a first embodiment of a rotor position detection device according to the present invention; FIG. It is a wave form diagram which shows each signal waveform in the said 1st Embodiment. It is a wave form diagram which shows the waveform of position detection signal HU ', HV', HW 'by a conventional system, and the waveform of each position detection signal HUs1, HVs1, HWs1 by the said 1st Embodiment. It is a wave form diagram which shows a waveform when the phase of position detection signal HV 'is delayed by 30 degrees in the conventional method, and a waveform when the phase of position detection signal HVs1 is delayed by 30 degrees in the first embodiment. It is a circuit diagram of 2nd Embodiment of the position detection apparatus of the rotor of this invention. It is a wave form diagram which shows each signal waveform in the said 2nd Embodiment. It is a circuit diagram of 3rd , 4th embodiment of this invention. 3 is a diagram schematically showing an example of attachment of first, second, and third Hall elements HU1, HV1, and HW1 to a circuit board 40. FIG. It is a figure which shows the control part 75 and switching circuit for energizing drive coil Lu, Lv, Lw 150 degrees using the 1st-6th position detection signal obtained in the said 2nd Embodiment. It is a wave form diagram which shows each signal waveform in the said conventional system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 1st comparator 2,12 2nd comparator 3,13 3rd comparator 14 4th comparator 15 5th comparator 16 6th comparator 31 Shaft 32,33 Bearing 35 Yoke 36 Magnet 37 Stator winding Line 38 Core 40 Circuit board 41 Rotor 42 Stator 51 Switching unit 52 Position estimation unit 53, 55 Signal line 58 Switching control unit HU, HU1 First Hall element HV, HV1 Second Hall element HUP, HUP1 First Output voltage HUM, HUM1 First inverted output voltage HVP, HVP1 Second output voltage HVM, HVM1 Second inverted output voltage HUs, HUs1 First position detection signal HVs, HVs1 Second position detection signal HWs, HWs1 Position detection signal 3 HW1 3rd Hall element HWP1 3rd output voltage HWM1 3rd inversion Power voltage HUs0 fourth position detection signals HVs0 fifth position detection signal HWs0 sixth position detection signals of the

Claims (5)

The magnetic flux of the rotor (41) is detected, and a first output signal (HUP) corresponding to the detected magnetic flux and a first inverted output signal (HUM) having an opposite phase to the first output signal are output. A first magnetic sensor (HU);
The magnetic flux of the rotor (41) is detected and a second output signal (HVP) corresponding to the detected magnetic flux and a second inverted output signal (HVM) having an opposite phase to the second output signal are output. A second magnetic sensor (HV) that
The first output signal (HUP) and the second output signal (HVP) are out of phase by a predetermined electrical angle,
A first comparator (1) to which the first output signal (HUP) and the first inverted output signal (HUM) are input;
A second comparator (2) to which the second output signal (HVP) and the second inverted output signal (HVM) are input;
A third comparator (to which the first output signal (HUP) and the second inverted output signal (HVM) or the first inverted output signal (HUM) and the second output signal (HVP) are input ( And 3) a rotor position detecting device. A first magnetic sensor (HU1) for detecting the magnetic flux of the rotor (41) and outputting a first output signal (HUP1) corresponding to the detected magnetic flux;
A second magnetic sensor (HV1) for detecting the magnetic flux of the rotor (41) and outputting a second output signal (HVP1) corresponding to the detected magnetic flux;
A third magnetic sensor (HW1) for detecting the magnetic flux of the rotor (41) and outputting a third output signal (HWP1) corresponding to the detected magnetic flux;
The first, second, and third output signals (HUP1, HVP1, HWP1) are out of phase with each other,
Further, a first comparator (11) to which the first output signal (HUP1) and the second output signal (HVP1) are input,
A second comparator (12) to which the second output signal (HVP1) and the third output signal (HWP1) are input;
A rotor position detecting device comprising: the third output signal (HWP1) and a third comparator (13) to which the first output signal (HUP1) is inputted. The rotor position detection device according to claim 2,
The first magnetic sensor (HU1) outputs the first output signal (HUP1) and a first inverted output signal (HUM1) having a phase opposite to that of the first output signal,
The second magnetic sensor (HV1) outputs the second output signal (HVP1) and a second inverted output signal (HVM1) having a phase opposite to that of the second output signal,
The third magnetic sensor (HW1) outputs the third output signal (HWP1) and a third inverted output signal (HWM1) having a phase opposite to that of the third output signal,
The first, second, and third output signals (HUP1, HVP1, HWP1) are out of phase with each other by 120 °.
A fourth comparator (14) to which the first output signal (HUP1) and the first inverted output signal (HUM1) are input;
A fifth comparator (15) to which the second output signal (HVP1) and the second inverted output signal (HVM1) are input;
A rotor position detecting device comprising: a sixth comparator (16) to which the third output signal (HWP1) and the third inverted output signal (HWM1) are inputted. The rotor position detection device according to claim 3,
The first, second, and third position detection signals (HUs1, HVs1, and HWs1) output from the first, second, and third comparators (11, 12, and 13), and the fourth, fifth, and fifth signals. The fourth, fifth, and sixth position detection signals (HUs0, HVs0, HWs0) output from the six comparators (14, 15, 16) are input, and the first, second, and third positions are input. The first state in which the detection signals (HUs1, HVs1, HWs1) are output but the fourth, fifth, and sixth position detection signals (HUs0, HVs0, HWs0) are not output, and the fourth, fifth, and fifth states. 6 is a switching unit capable of switching to a second state in which position detection signals (HUs0, HVs0, HWs0) are output but the first, second and third position detection signals (HUs1, HVs1, HWs1) are not output. (51) A rotor position detecting device characterized by comprising: The rotor position detecting device according to claim 4,
A first energization control for energizing the stator winding (37) for driving the rotor (41) by 150 ° while setting the switching unit (51) to the first state, and the switching unit (51) A motor drive circuit comprising a control unit (58) capable of performing the second energization control in which the stator winding (37) is energized 120 ° in the second state.

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