JP2006034049A - Brushless motor controller and brushless motor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brushless-motor controller capable of smoothly restarting a sensorless brushless motor. <P>SOLUTION: This sensorless brushless motor 10 controller 20 includes an inverter circuit 20A, an induced-voltage sampler 20B, a pseudo induced-voltage detector 20C, a pulse position signal detector 20D, a phase corrector 20E, and an energization logic control unit 20F. The induced-voltage sampler 20B is connected between an anode power line 25a and stator windings 11u, 11v, 11w, and includes bias resistors 23u, 23v, 23w for applying a bias voltage to each of voltage-dividing resistors 24u1 to 24w2 to output a full-wave induced-voltage signal from the voltage-dividing resistors 24u1 to 24w2, respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

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

  Hereinafter, a brushless motor device according to the related art configured in the same manner as Patent Document 1 will be described with reference to FIGS. 5 and 6 are diagrams showing a configuration of a brushless motor device according to the prior art, and FIGS. 7 and 8 are diagrams showing signal waveforms in the brushless motor device shown in FIG.

  The conventional brushless motor apparatus 201 includes an analog rotational position detection circuit A for estimating the rotational position of the rotor 212. The rotational position detection circuit A is output from an induced voltage sampling unit 220B (resistance voltage dividing circuit) for detecting the induced voltage induced in the stator windings 211u, 211v, and 211w and the induced voltage sampling unit 220B. A pseudo induced voltage detector 220C (low pass filter) that integrates the induced voltage signal, and a pulse position signal detector 220D (comparator) that compares the pseudo induced voltage signal output from the pseudo induced voltage detector 220C with a neutral potential. Is provided.

  In the conventional brushless motor apparatus 201, the rotation pulse position signal output from the rotation position detection circuit A is input to the microcomputer 220E, and the microcomputer 220E generates a commutation signal based on the rotation pulse position signal. ing. Further, the commutation signal generated by the microcomputer 220E is output to the inverter circuit unit 220A via the driver circuit 220F, and the stator windings 211u, Current sequentially flows through 211v and 211w. A driving magnetic field is generated by sequentially flowing current through the stator windings 211u, 211v, 211w, and the rotor 212 is rotated by this driving magnetic field.

  Incidentally, in the brushless motor device 201, when any abnormality occurs during the rotation of the rotor 212, all the switching elements 221a to 221f of the inverter circuit unit 220A are turned off. In order to restart the brushless motor 210 from this state, it is necessary to detect the rotational position of the rotor 212 before the inverter circuit unit 220A starts outputting the commutation signal. In other words, it is necessary to detect the rotational position of the rotor 212 and to pass current sequentially through the stator windings 211u, 211v, and 211w in accordance with the rotational position of the rotor 212.

  Here, even when all the switching elements 221a to 221f of the inverter circuit unit 220A are turned off due to some abnormality during the rotation of the rotor 212, when the rotor 212 rotates by inertia, the rotation As the child 212 rotates, an induced voltage is induced in the stator windings 211u, 211v, and 211w of the U, V, and W phases.

  At this time, the induced voltages induced in the stator windings 211u, 211v, and 211w of each phase of U, V, and W are all sine waves as shown in FIG. For example, at time t in FIG. 7, the induced voltage induced in the U-phase stator winding 211u and the induced voltage induced in the W-phase stator winding 211w become positive, and the V-phase stator winding The induced voltage induced by 211v is negative.

  When all the switching elements 221a to 221f of the inverter circuit unit 220A are turned off, the current flow in the stator windings 211u, 211v, and 211w of each phase at the time t is as shown in FIG. That is, if the current flowing through the U-phase stator winding 211u is Iu ′, the current flowing through the V-phase stator winding 211v is Iv ′, and the current flowing through the W-phase stator winding 211w is Iw ′, The relationship is Iu ′ + Iv ′ + Iw ′ = 0.

  At time t, as shown in FIG. 7, the induced voltage induced in the U-phase stator winding 211u and the induced voltage induced in the W-phase stator winding 211w are both positive. . Therefore, the current Iu ′ flowing through the U-phase stator winding 211u and the current Iw ′ flowing through the W-phase stator winding 211w are both positive. On the other hand, the current Iv ′ flowing through the V-phase stator winding 211v is in the negative direction. That is, Iv ′ = − (Iu ′ + Iw ′).

  If the current flowing through the voltage dividing resistors 224u1 and 224u2 is I1 'and the current flowing through the voltage dividing resistors 224w1 and 224w2 is I3', I1 '= Iu' and I3 '= Iw'. Further, the output voltage of the induced voltage signal output from the intermediate connection portion of the voltage dividing resistors 224u1 and 224u2 is Vu1 ′, and the output voltage of the induced voltage signal output from the intermediate connection portion of the voltage dividing resistors 224w1 and 224w2 is Vw1. Then, the output voltages of these induced voltage signals are Vu1 ′ = I1 ′ × R4 ′ and Vw1 ′ = I3 ′ × R6 ′. R4 'and R6' are resistance values of the voltage dividing resistors 224u2 and 224w2.

  On the other hand, when the current flowing through the voltage dividing resistors 224v1 and 224v2 is I2 ', I2' is as follows. That is, when the absolute value of the negative induced voltage at the V terminal is larger than the forward voltage (usually about 0.7 V) of the diode 222e, the diode 222e is turned on. In this case, the V-phase stator winding is turned on. The current flowing through the line 211v is Iv ′ = I5 ′ + I2 ′. Note that I5 'is a current flowing through the diode 222e. Therefore, in this case, the current flowing through the voltage dividing resistors 224v1 and 224v2 is I2 '= Iv'-I5'. Note that I5 'is very small compared to the current Iv' flowing through the stator winding 211v.

  When the absolute value of the negative induced voltage at the V terminal is smaller than the forward voltage of the diode 222e, the diode 222e is turned off, and in this case, I5 '= 0. That is, the current flowing through the voltage dividing resistors 224v1 and 224v2 is I2 '= Iv'.

  Therefore, when a negative induced voltage is generated at the V terminal, if the absolute value of the negative induced voltage at the V terminal is larger than the forward voltage of the diode 222e, the negative induced voltage at the V terminal is the forward voltage of the diode 222e. Clamped to directional voltage.

  When the induced voltage signal output from the intermediate connection portion of the voltage dividing resistors 224v1 and 224v2 is Sv1 ′, the induced voltage signal Sv1 ′ has a sine wave minus portion as a diode as shown in FIG. A constant value is obtained by clamping to the forward voltage of 222e. That is, the induced voltage signal Sv1 'is a half wave.

Subsequently, when this half-wave induced voltage signal Sv1 ′ is integrated by the pseudo-induced voltage detector 220C, a pseudo-induced voltage signal Sv2 ′ is obtained as shown in FIG. 8B. Further, when the output voltage of the pseudo induced voltage signal Sv2 ′ output from the V-phase output terminal of the pseudo induced voltage detector 220C is compared with the reference voltage Sc ′ in the pulse position signal detector 220D, as shown in FIG. 8C. In addition, a rectangular rotation pulse position signal Sv3 ′ is obtained. The reference voltage Sc ′ is formed by the reference voltage generating resistors 229u, 229v, and 229w.
Japanese Patent Laid-Open No. 2002-119084 (page 4-6, FIGS. 1 to 3)

  However, in the brushless motor apparatus 201 according to the above-described conventional technology, as described above, the induced voltage signal Sv1 'output from the induced voltage sampling unit 220B is a half wave. Therefore, since the subsequent pseudo-induced voltage detection unit 220C performs integration based on the half-wave induced voltage signal Sv1 ′, the amplitude of the pseudo-induced voltage signal Sv2 ′ output from the pseudo-induced voltage detection unit 220C is reduced ( (Refer FIG.8 (b)). Further, in the pulse position signal detection unit 220D, the rotation pulse position signal Sv3 ′ is generated based on the pseudo-inductive voltage signal Sv2 ′ having a small amplitude, so that the phase shift of the rotation pulse position signal Sv3 ′ becomes large (FIG. 8 (c)).

  Therefore, when the rotational pulse position signal Sv3 ′ has a large phase shift as described above, the microcomputer 220E cannot accurately estimate the rotational position of the rotor 212. Therefore, when the brushless motor 10 is restarted, In some cases, problems such as adjustment or the rotor 212 stopping may occur.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a brushless motor capable of smoothly restarting a brushless motor in a control device for controlling a so-called sensorless brushless motor. It is to provide a control device.

  Another object of the present invention is to provide a brushless motor device that can smoothly restart a brushless motor in a brushless motor device having a so-called sensorless brushless motor.

  According to the present invention, a plurality of switching elements are bridge-connected between an anode power supply line and a cathode power supply line, and a bridge connection portion between the plurality of switching elements is formed in a stator winding of a brushless motor. An inverter circuit unit connected, and a voltage dividing resistor connected between the stator winding and the cathode power supply line and outputting an induced voltage signal based on an induced voltage induced in the stator winding A brushless motor comprising: an induced voltage sampling unit configured to have; and a control circuit unit that outputs a commutation signal to the plurality of switching elements based on the induced voltage signal output from the induced voltage sampling unit. In the control device, the induced voltage sampling unit applies a bias voltage to the voltage dividing resistor connected between the anode power supply line and the stator winding. The bias resistor is provided, it is solved by.

  As described above, if the induced voltage sampling unit is provided with the bias resistor connected between the anode power supply line and the stator winding and applying the bias voltage to the voltage dividing resistor, the induced voltage is induced in the stator winding. Since a positive bias voltage can be added to the induced voltage, the induced voltage signal output from the induced voltage sampling unit can be made full wave.

  Here, it is preferable that the bias resistor is connected to an anode power supply line different from the anode power supply line to which the switching element of the inverter circuit unit is connected. That is, it is preferable that the power supply device that supplies power to the inverter circuit unit and the power supply device that supplies power to the bias resistor are different. In this case, even when power is supplied to the anode power supply line to which the switching element is connected, power is not supplied to the bias resistor in this state, so that it is possible to keep power consumption in a so-called standby state low. .

  In a brushless motor device comprising a control circuit for controlling the brushless motor, it is preferable that the brushless motor control device according to claim 1 or 2 is used for the control circuit.

  Thus, according to the present invention, since the induced voltage signal output from the induced voltage sampling unit can be a full wave, the phase of the rotation pulse position signal output to the control circuit unit as compared with the prior art. Deviation can be reduced. Thereby, since the rotational position detection accuracy of the rotor can be improved, it is possible to prevent problems such as step-out and rotation stoppage in the brushless motor.

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

  1 to 3 are diagrams showing an embodiment of the present invention, FIG. 1 is a diagram showing a configuration of a brushless motor device, FIG. 2 is a diagram showing a current flow in the brushless motor device, and FIG. 3 is a diagram of the brushless motor device. It is a figure which shows each signal waveform.

First, the configuration of a brushless motor device according to an embodiment of the present invention will be described with reference to FIG.
A brushless motor device 1 according to an embodiment of the present invention shown in FIG. 1 is preferably used for a cooling device that cools a radiator of an engine provided in a vehicle (not shown). The controller 20 is configured as a control device.

  The brushless motor 10 includes a stator 11 that generates a driving magnetic field and a rotor 12 that rotates by the driving magnetic field generated from the stator 11. The stator 11 is provided with U-phase, V-phase, and W-phase stator windings 11u, 11v, and 11w connected in a Y-shape, and the rotor 12 has a permanent magnet (reference numeral in FIG. 1). (Omitted) is provided.

  The controller 20 is supplied with power from the DC power supply device 30 and drives the brushless motor 10, and is constituted by, for example, a one-chip electric circuit, a small control device, or the like. The controller 20 of this example includes an inverter circuit unit 20A, an induced voltage sampling unit 20B, a pseudo induced voltage detection unit 20C, a pulse position signal detection unit 20D, a phase correction unit 20E, and an energization logic control unit 20F. Configured.

  The inverter circuit unit 20A is configured by a so-called full-wave drive circuit in which an upper arm and a lower arm are bridge-connected. That is, the upper arm of the inverter circuit unit 20A is configured by switching elements 21a, 21b, and 21c and diodes 22a, 22b, and 22c, and the lower arm is configured by switching elements 21d, 21e, and 21f and diodes 22d, 22e, and 22f. ing.

  The switching elements 21a to 21f are configured by n-channel MOSFETs, and are bridge-connected between the anode power supply line 25a and the cathode power supply line 25b in three phases of U phase, V phase, and W phase. The drains of the switching elements 21a, 21b, and 21c are connected to the anode power supply line 25a, respectively, and the sources of the switching elements 21d, 21e, and 21f are connected to the cathode power supply line 25b, respectively.

  Further, the gates of the switching elements 21a to 21f are respectively connected to the output terminals of the energization logic control unit 20F, and the intermediate connection unit U in each bridge connection of the switching elements 21a, 21b, 21c and the switching elements 21d, 21e, 21f. , V and W are connected to the stator windings 11u, 11v and 11w, respectively.

  The switching elements 21a, 21b, and 21c switch the current flow from the anode power supply line 25a to the stator windings 11u, 11v, and 11w based on the commutation signal given to the gate. The switching elements 21d, 21e, and 21f switch the flow of current from the stator windings 11u, 11v, and 11w to the cathode power supply line 25b based on the commutation signal given to the gate.

  The diodes 22a to 22f are for releasing a surge voltage generated by switching of the switching elements 21a to 21f. The diodes 22a to 22f of the present example are connected in parallel to the switching elements 21a to 21f, respectively, and are wired so as to be in the opposite direction to the current flow from the anode power supply line 25a to the cathode power supply line 25b. . The diodes 22a to 22f are built in the switching elements 21a to 21f made of MOSFET, respectively.

  The induced voltage sampling unit 20B is for detecting the induced voltage induced in the stator windings 11u, 11v, 11w according to the rotation of the rotor 12, and includes the bias resistors 23u, 23v, 23w, The piezoelectric resistors 24u1, 24u2, 24v1, 24v2, 24w1, 24w2 are provided.

  The bias resistors 23u, 23v, and 23w apply bias voltages to the U, V, and W terminals of the stator windings 11u, 11v, and 11w. The bias resistor 23u is connected between the stator winding 11u and the anode power supply line 25a so as to be in parallel with the switching element 21a. Similarly, the bias resistor 23v is connected between the stator winding 11v and the anode power supply line 25a so as to be parallel to the switching element 21b, and the bias resistor 23w is parallel to the switching element 21c. Thus, the stator winding 11w and the anode power supply line 25a are connected. The bias resistors 23u, 23v, and 23w all have the same resistance value (for example, 1 kΩ to 100 kΩ).

  The voltage dividing resistors 24u1 and 24u2 are for dividing the terminal voltage of the stator winding 11u. Similarly, the voltage dividing resistors 24v1 and 24v2 are for dividing the terminal voltage of the stator winding 11v, and the voltage dividing resistors 24w1 and 24w2 are for dividing the terminal voltage of the stator winding 11w. belongs to. The voltage dividing resistors 24u1, 24u2, 24v1, 24v2, 24w1, and 24w2 all have equal resistance values.

  The voltage dividing resistors 24u1 and 24u2 are connected in series between the stator winding 11u and the cathode power supply line 25b. Similarly, the voltage dividing resistors 24v1 and 24v2 are connected in series between the stator winding 11v and the cathode power supply line 25b, and the voltage dividing resistors 24w1 and 24w2 are connected to the stator winding 11w and the cathode power supply. The line 25b is connected in series.

  Further, an intermediate connection portion between the voltage dividing resistor 24u1 and the voltage dividing resistor 24u2 is connected to an input terminal of the pseudo-induced voltage detection unit 20C. Similarly, an intermediate connection portion between the voltage dividing resistor 24v1 and the voltage dividing resistor 24v2 and an intermediate connection portion between the voltage dividing resistor 24w1 and the voltage dividing resistor 24w2 are also connected to the input terminal of the pseudo-induced voltage detection unit 20C. Yes. With this configuration, the induced voltage sampling unit 20B can output the U-phase, V-phase, and W-phase induced voltage signals to the pseudo-induced voltage detection unit 20C.

  In the state where the switching elements 21a to 21f are all off and the rotor 12 is stopped, the bias voltage by the bias resistor 23u is applied to the resistance voltage dividing circuit including the U-phase voltage dividing resistors 24u1 and 24u2. Since the voltage is applied, the U-phase terminal voltage Vu becomes Vu = (R1 + R4) × Vb / (R10 + R1 + R4). R1 is a resistance value of the voltage dividing resistor 24u1, R4 is a resistance value of the voltage dividing resistor 24u2, Vb is an output voltage value of the DC power supply device 30, and R10 is a resistance value of the bias resistor 23u. The same applies to the V-phase terminal voltage Vv and the W-phase terminal voltage Vw. The U-phase terminal voltage Vu, the V-phase terminal voltage Vv, and the W-phase terminal voltage Vw are all equal. Furthermore, Vc = Vu = Vv = Vw is also established for the potential Vc at the Y connection center point of the stator windings 11u, 11v, 11w.

  The pseudo-induced voltage detection unit 20 </ b> C is configured by a low-pass filter (integration circuit) including a resistor 26 and a capacitor 27. The pseudo induced voltage detection unit 20C of this example integrates the induced voltage signals of the respective phases output from the induced voltage sampling unit 20B, and generates pseudo induced voltage signals of the U phase, the V phase, and the W phase. This is configured to be output to the pulse position signal detector 20D.

  The pulse position signal detection unit 20D includes a comparator 28 corresponding to each of the U phase, the V phase, and the W phase. Each phase comparator 28 receives the pseudo induced voltage signal of each phase output from the pseudo induced voltage detector 20C and the reference voltage signal generated by the reference potential generating resistors 29u, 29v, 29w. It has become. Further, the comparator 28 for each phase in this example compares the pseudo induced voltage signal output from the pseudo induced voltage detector 20C with the reference voltage signal generated by the reference potential generating resistors 29u, 29v, 29w. The zero cross signal is generated and output to the phase correction unit 20E as a rotation pulse position signal.

  The phase correction unit 20E delays the phase of the rotation pulse position signal output from the pulse position signal detection unit 20D until the commutation timing.

  The energization logic control unit 20F performs a predetermined calculation based on a control signal output from an external controller (not shown) and generates a six-phase commutation signal based on the rotation pulse position signal output from the phase correction unit 20E. This is output to the gates of the switching elements 21a to 21f.

Next, the operation of the brushless motor device 1 configured as described above will be described with reference to FIGS. 1 to 3.
When a control signal output from a host controller (not shown) is input to the energization logic control unit 20F, the energization logic control unit 20F outputs a commutation signal based on a synchronization signal output from a synchronization signal output circuit (not shown). This is generated and output to the inverter circuit unit 20A.

  When a commutation signal is input to the inverter circuit unit 20A, the switching elements 21a to 21f are sequentially switched. When the switching elements 21a to 21f are sequentially switched, a current flows through the stator windings 11u, 11v, and 11w in a predetermined order, and the stator in which a current flows among the stator windings 11u, 11v, and 11w. A driving magnetic field is generated from the winding, and forced driving of the brushless motor 10 is started.

  Subsequently, the speed of the rotor 12 is increased by shortening the synchronization signal switching cycle. Then, the forced drive is switched to the sensorless drive in a state where the switching period of the synchronization signal becomes a predetermined value. That is, the energization logic control unit 20F generates a commutation signal based on the rotation pulse position signal output from the pulse position signal detection unit 20D, thereby rotating the rotor 12 by a sensorless method.

  Here, in the brushless motor device 1 of this example, when any abnormality occurs during the rotation of the rotor 12, all the switching elements 21a to 21f of the inverter circuit unit 20A are turned off. As a result, the driving magnetic fields of the stator windings 11u, 11v, and 11w disappear, and the rotor 12 becomes free. As a result, the rotor 12 continues to rotate with inertia. Here, even when all of the switching elements 21a to 21f of the inverter circuit unit 20A are turned off due to some abnormality during the rotation of the rotor 12, when the rotor 12 rotates by inertia, the rotation As the child 12 rotates, an induced voltage is induced in the stator windings 11u, 11v, and 11w (see, for example, FIG. 7).

  Here, the current flowing through the stator windings 11u, 11v, 11w of each phase at time t in FIG. 7 will be described with reference to FIG. As shown in FIG. 2, if the current flowing through the U-phase stator winding 11u is Iu, the current flowing through the V-phase stator winding 11v is Iv, and the current flowing through the W-phase stator winding 11w is Iw. These relationships are Iu + Iv + Iw = 0.

  Further, currents flowing through the bias resistors 23u, 23v, and 23w are I10, I11, and I12, currents flowing through the voltage dividing resistors 24u1 and 24u2 are I1, currents flowing through the voltage dividing resistors 24v1 and 24v2 are I2, and voltage dividing resistors Assuming that the current flowing through the capacitors 24w1 and 24w2 is I3, I1 = I10 + Iu, I2 = I11−Iv, and I3 = I12 + Iw.

  Further, the output voltage of the induced voltage signal output from the intermediate connection portion of the voltage dividing resistors 24u1 and 24u2 is Vu1, the output voltage of the induced voltage signal output from the intermediate connection portion of the voltage divider resistors 24v1 and 24v2 is Vv1, When the output voltage of the induced voltage signal output from the intermediate connection portion of the voltage dividing resistors 24w1 and 24w2 is Vw1, the output voltage of the induced voltage signal of each phase is Vu1 = I1 × R4, Vv1 = I2 × R5, Vw1. = I3 × R6. R4, R5, and R6 are resistance values of the voltage dividing resistors 24u2, 24v2, and 24w2.

  As shown in FIG. 2, the flow of the resistance voltage dividing circuit in each phase at time t in FIG. 7 is I1 = I10 + Iu> 0, I2 = I11−Iv> 0, and I3 = I12 + Iw> 0. Thus, in any resistance voltage dividing circuit, the current flow is in the positive direction.

  In particular, for the V phase, unlike the induced voltage sampling unit (220B) according to the prior art, the diode 22e remains off and I2> 0 and Vv1> 0. Therefore, the induced voltage signal Sv1 output from the V phase of the induced voltage sampling unit 20B is a full wave as shown in FIG.

  Then, when this full-wave induced voltage signal Sv1 is integrated by the pseudo-induced voltage detection unit 20C formed of a low-pass filter, a pseudo-induced voltage signal Sv2 is obtained as shown in FIG. Further, when the output voltage of the pseudo induced voltage signal Sv2 output from the V-phase output terminal of the pseudo induced voltage detector 20C is compared with the reference voltage Sc in the pulse position signal detector 20D, as shown in FIG. A rectangular rotation pulse position signal Sv3 is obtained. The reference voltage Sc is formed by the reference voltage generating resistors 29u, 29v, 29w.

  Here, in FIG. 3, what are indicated by broken lines are the induced voltage signal Sv1 ′, the pseudo induced voltage signal Sv2 ′, and the rotation pulse position signal Sv3 ′ according to the prior art shown for comparison with the present invention. .

  In this example, since the induced voltage signal Sv1 output from the induced voltage sampling unit 20B is a full wave, the pseudo induced voltage signal Sv2 ′ is generated from the induced voltage signal Sv1 ′ that is a half wave as in the prior art. In comparison with FIG. 3, the amplitude of the pseudo-induced voltage signal Sv2 can be increased as shown in FIG.

  Further, in this example, the amplitude of the pseudo-induced voltage signal Sv2 output from the pseudo-induced voltage detection unit 20C is larger than that of the conventional one, so that it is compared with the conventional rotation pulse position signal Sv3 ′ as shown in FIG. Thus, the phase shift of the rotation pulse position signal Sv3 can be reduced. That is, ideally, the rotation pulse position signal Sv3 (Sv3 ′) rises when the phase of the induced voltage signal Sv1 (Sv1 ′) is 0 ° (time t0) to 90 ° (time t1). The phase of the position signal Sv3 ′ is shifted by −β.

  On the other hand, in this example, the phase shift of the rotation pulse position signal Sv3 remains at −α, which is smaller than the conventional one. Thus, in this example, the phase shift of the rotation pulse position signal Sv3 can be reduced as compared with the conventional rotation pulse position signal Sv3 '.

  The rotation pulse position signal Sv3 output from the pulse position signal detection unit 20D is delayed by a predetermined phase in the phase correction unit 20E. The reason for delaying the phase is to bring the rise time of the rotation pulse position signal Sv3 to the ideal rise time (time t1).

  Then, a six-phase commutation signal is generated based on the rotation pulse position signal Sv3 output from the phase correction unit 20E, and is output to the gates of the switching elements 21a to 21f. As a result, current flows through the stator windings 11u, 11v, and 11w in a predetermined order, and a driving magnetic field is generated from the stator winding through which the current flows among the stator windings 11u, 11v, and 11w. 10 is restarted.

  At this time, in this embodiment, since the phase shift of the rotation pulse position signal Sv3 is small, the rotation position detection accuracy of the rotor 12 can be improved. Therefore, the brushless motor 10 can be smoothly restarted without causing problems such as step-out and rotation stoppage.

As described above, according to the present embodiment, the following effects are obtained.
(A) According to the present embodiment, since the induced voltage signal Sv1 output from the induced voltage sampling unit 20B is a full wave, a pseudo induced voltage signal is generated from the induced voltage signal Sv1 ′ that is a half wave as in the prior art. Compared to the case of generating Sv2 ′, the amplitude of the pseudo-induced voltage signal Sv2 can be increased as shown in FIG.

  (B) According to the present embodiment, since the amplitude of the pseudo induced voltage signal Sv2 output from the pseudo induced voltage detection unit 20C is larger than that of the conventional case, as shown in FIG. Compared with Sv3 ′, the phase shift of the rotation pulse position signal Sv3 can be reduced.

  (C) According to the present embodiment, the phase shift of the rotation pulse position signal Sv3 can be reduced, so that the rotation position detection accuracy of the rotor 12 can be improved. Therefore, it is possible to prevent problems such as step-out and rotation stoppage in the brushless motor 10.

The embodiment of the present invention can be modified as follows.
That is, in the above embodiment, the bias resistors 23u, 23v, and 23w are connected to the anode power supply line 25a that is common to the inverter circuit unit 20A, but the present invention is not limited to this. In addition, for example, as in the brushless motor device 101 according to the modification shown in FIG. 4, the bias resistors 23u, 23v, and 23w are connected to the anode power supply line 25a to which the switching elements 21a to 21f of the inverter circuit unit 20A are connected. It may be connected to a different anode power line 125a. That is, the DC power supply 30 that supplies power to the inverter circuit unit 20A and the DC power supply 130 that supplies power to the bias resistors 23u, 23v, and 23w may be configured separately.

  Thus, when the DC power supply 30 that supplies power to the inverter circuit unit 20A and the DC power supply 130 that supplies power to the bias resistors 23u, 23v, and 23w are different, the anode to which the switching elements 21a to 21f are connected. Even if power is supplied to the power supply line 25a, power is not supplied to the bias resistors 23u, 23v, and 23w in this state, so that power consumption in a so-called standby state can be kept low. In FIG. 4, the members according to the above embodiment are shown using the same reference numerals.

It is a figure which shows the structure of the brushless motor apparatus which concerns on one Embodiment of this invention. It is a figure which shows the flow of the electric current in the brushless motor apparatus which concerns on one Embodiment of this invention. It is a figure which shows each signal waveform of the brushless motor apparatus which concerns on one Embodiment of this invention. It is explanatory drawing which shows the structure of the brushless motor apparatus which concerns on the modification of this embodiment. It is a figure which shows the structure of the brushless motor apparatus which concerns on a prior art. It is a figure which shows the flow of the electric current in the brushless motor apparatus which concerns on a prior art. It is a figure which shows the voltage waveform of the induced voltage in the brushless motor apparatus which concerns on a prior art. It is a figure which shows each signal waveform of the brushless motor apparatus which concerns on a prior art.

Explanation of symbols

1,101,201 Brushless motor device, 10,210 Brushless motor, 11 Stator, 11u, 11v, 11w, 211u, 211v, 211w Stator winding, 12,212 Rotor, 20 Controller, 20A, 220A Inverter circuit section , 20B, 220B induced voltage sampling unit, 20C, 220C pseudo induced voltage detection unit, 20D, 220D pulse position signal detection unit, 20E, 220E phase correction unit, 20F, 220F energization logic control unit, 21a, 21b, 21c, 21d, 21e, 21f, 221a, 221b, 221c, 221d, 221e, 221f Switching element, 22a, 22b, 22c, 22d, 22e, 22f, 222e Diode, 23u, 23v, 23w Bias resistor, 24u1, 24u2, 4v1, 24v2, 24w1, 24w2, 224u1, 224u2, 224v1, 224v2, 224w1, 224w2 Voltage divider resistor, 25a, 125a Anode power line, 25b Cathode power line, 26 Resistor, 27 Capacitor, 28 Comparator, 29u, 29v, 29w, 229u, 229v, 229w Reference voltage generating resistor, 30, 130 DC power supply

Claims (3)

An inverter circuit unit in which a plurality of switching elements are bridge-connected between an anode power source line and a cathode power source line, and a bridge connection part between the plurality of switching elements is connected to a stator winding of a brushless motor;
Induced voltage sampling comprising a voltage dividing resistor connected between the stator winding and the cathode power supply line and outputting an induced voltage signal based on the induced voltage induced in the stator winding. And
A control circuit unit that outputs a commutation signal to the plurality of switching elements based on the induced voltage signal output from the induced voltage sampling unit;
The induction voltage sampling unit includes a bias resistor connected between the anode power supply line and the stator winding for applying a bias voltage to the voltage dividing resistor. Control device. An inverter circuit unit in which a plurality of switching elements are bridge-connected between an anode power source line and a cathode power source line, and a bridge connection part between the plurality of switching elements is connected to a stator winding of a brushless motor;
Induced voltage sampling comprising a voltage dividing resistor connected between the stator winding and the cathode power supply line and outputting an induced voltage signal based on the induced voltage induced in the stator winding. And
A control circuit unit that outputs a commutation signal to the plurality of switching elements based on the induced voltage signal output from the induced voltage sampling unit;
The induced voltage sampling unit applies a bias voltage to the voltage dividing resistor connected between an anode power supply line connected to a power supply different from a power supply connected to the anode power supply line and the stator winding. A control device for a brushless motor, characterized in that a bias resistor is provided. In a brushless motor device comprising a control circuit for controlling a brushless motor,
A brushless motor device using the brushless motor control device according to claim 1 or 2 in the control circuit.

Images