JP4486195B2 - Position sensorless motor controller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a position sensorless motor control device that smoothly starts a brushless motor without using a position sensor, and in particular, position sensorless motor control that can smoothly start a brushless motor even when the rotor is in a rotating state. Relates to the device.
[0002]
[Prior art]
The brushless motor is highly efficient because it uses a permanent magnet for the field, and has excellent maintainability because it does not use a mechanical commutation mechanism. Therefore, brushless motors are used for various purposes such as fans and pumps.
However, the brushless motor needs to pass a current through the phase winding of the stator in synchronization with the rotation of the rotor.
In a conventional motor control device that controls the drive of such a brushless motor, the rotor angle information is obtained using a position sensor such as a Hall element, a resolver, or an optical encoder attached to the brushless motor. Therefore, since it is necessary to provide such a position sensor, the conventional brushless motor has been increased in cost and increased in size.
[0003]
As a conventional position sensorless motor control device that realizes cost reduction and miniaturization by omitting such a position sensor, the Institute of Electrical Engineers of Japan, Vol. 117, No. 1, 1997, p. 98-104. Those described in the page, and those described in the Institute of Electrical Engineers of Japan, Semiconductor Power Conversion Study Group, SPC-97-7, pages 37-42 are known. Hereinafter, these conventional position sensorless motor control devices will be described.
[0004]
The former conventional position sensorless motor control device estimates the angle of the rotor of the brushless motor during rotation at a certain speed.
This conventional position sensorless motor control device first detects a phase current flowing through a phase winding, and performs coordinate conversion of these phase current values to create a γ-axis current value iγ and a δ-axis current value iδ. Next, motor constants are applied to the d-axis and q-axis voltage equations indicating the model of the brushless motor to create a γ-axis current model value iγm and a δ-axis current model value iδm. Furthermore, a γ-axis current error value Δiγ and a δ-axis current error value Δiδ, which are errors between these current values and current model values, are created. Then, the estimated angle and the estimated induced voltage are corrected based on these current error values. Using the estimated angle thus created, a predetermined current is passed through the phase winding to rotate the rotor in a predetermined direction.
[0005]
On the other hand, the latter conventional position sensorless motor control device estimates the angle of the rotor of a brushless motor having a saliency when stopped or at a low speed.
This conventional position sensorless motor control device first applies a voltage pulse to the γ-axis. Next, the current response of the phase current due to this voltage pulse is detected, and the current response of these phase currents is transformed to create a γ-axis current response Δiγ and a δ-axis current response Δiδ. By the way, the inductance of the brushless motor having saliency changes in accordance with the rotation of the rotor. Therefore, an estimated angle is created based on the γ-axis current response Δiγ and the δ-axis current response Δiδ using the fact that the current response changes due to the inductance. Using the estimated angle thus created, a current is passed through the phase winding to rotate the rotor in a predetermined direction.
[0006]
Moreover, in order to rotate the motor stopped at the time of starting at high speed, it drives by the following method.
First, the system is activated by the method used in the latter conventional position sensorless motor control device. Next, the system is appropriately switched to the method used in the former conventional position sensorless motor control device, and accelerated to high speed and rotated.
[0007]
[Problems to be solved by the invention]
When a brushless motor is used for a fan or the like, when a strong wind is blowing at the time of startup, the motor may rotate due to the influence of the wind. In this way, when the motor is rotating at the time of start-up, as with the case where the motor is stopped at the time of start-up as described above, if it is started by the method used in the latter conventional position sensorless motor control device, it starts smoothly I couldn't make it.
An object of the present invention is to realize a position sensorless motor control device capable of smoothly starting a brushless motor even when the rotor is rotating at the time of startup.
[0008]
[Means for Solving the Problems]
  To achieve the above object, according to the present invention.Of the first viewpointThe position sensorless motor control devicePosition sensorless motor control apparatus for controlling a brushless motor having a rotor in which a permanent magnet is disposed and rotatably supported, a stator disposed in the vicinity of the rotor, and a phase winding wound around the stator Because
  Drive means for applying a voltage based on a voltage command value representing a command value of the voltage applied to the phase winding;
  SaidA plurality of activation means for activating the brushless motor;
  A current zero control unit for creating a voltage command value for controlling the current flowing in the phase winding to zero;
  Created the current zero control unitSelecting means for selecting one starting means from the plurality of starting means based on the voltage command value;And
  The starting means selected by the selecting means is configured to calculate the angle and speed of the rotor based on the voltage command value that makes the current flowing through the phase winding zero.
  With this configuration,The position sensorless motor control device of the first aspect isA position sensorless motor control device that smoothly starts a brushless motor even when the rotor is rotating is realized by selecting and operating an appropriate starting unit according to the magnitude of the voltage command value when the current is controlled to zero. be able to.In addition, the position sensorless motor control device according to the first aspect can realize a position sensorless motor control device that does not generate torque by controlling the current to zero during the startup period.
[0009]
  Second aspect of the present inventionThe position sensorless motor control device ofThe plurality of activation means in the first aspect are:First activation means for activating the brushless motor at high speed, and second activation means for activating the brushless motor at low speed,Have
  The selection means includes the phase windingCurrent flowing throughTo zeroWhen controllingSaidSelecting the first starting means when the voltage command value is greater than the threshold value;Said phase windingCurrent flowing throughTo zeroThe second activation means is selected when the voltage command value when controlled to be smaller than a threshold valueIs configured as.
  With this configuration,The position sensorless motor control device of the second aspect isRealizing a position sensorless motor control device that can always select the optimal starting part even if the induced voltage changes due to temperature change, etc., by selecting the starting part according to the voltage command value equivalent to the induced voltage Can do.
[0010]
  Third aspect of the present inventionThe position sensorless motor control device ofYou may comprise the said 2nd starting means in a said 2nd viewpoint so that the change of the inductance accompanying rotation of the rotor of the said brushless motor may be utilized. With this configuration, it is possible to realize a position sensorless motor control device that does not generate torque by controlling the current to zero during the startup period.
[0011]
  In the position sensorless motor control apparatus according to the fourth aspect of the present invention, the second starting means according to the second aspect may be configured to utilize magnetic flux saturation.With this configuration, it is possible to realize a position sensorless motor control device that does not generate torque by controlling the current to zero during the startup period.
[0012]
  Fifth aspect of the present inventionThe position sensorless motor control device ofIn the second aspectThe first starting means has a current flowing through the phase winding.To zeroControlling the voltage command value so as to calculate the angle and speed of the rotor based on the voltage command value,
  The second starting means has a current flowing through the phase winding.To zeroAnd calculate the angle and speed of the rotor using the change in inductance caused by the rotation of the rotor.Is configured as.
  With this configuration, position sensorless motor control that smoothly starts the brushless motor even when the rotor is rotating by selecting and operating the appropriate starting unit according to the magnitude of the voltage command value when the current is controlled to zero An apparatus can be realized. In addition, this configuration realizes a position sensorless motor control device that always selects the optimum starting part even if the induced voltage changes due to temperature change, etc., by selecting the starting part with a voltage command value equivalent to the induced voltage. can do. Furthermore, with this configuration, it is possible to realize a position sensorless motor control device that does not generate torque by controlling the current to zero during the startup period.
[0013]
  Sixth aspect of the present inventionThe position sensorless motor control device ofIn the second aspectThe first activation means,Current flowing in the phase windingTo zeroControlling the voltage command value so as to calculate the angle and speed of the rotor based on the voltage command value,
  The second starting means,Current flowing in the phase windingTo zeroAnd calculate the rotor angle and speed using magnetic flux saturation.Is configured as.
  With this configuration, position sensorless motor control that smoothly starts the brushless motor even when the rotor is rotating by selecting and operating the appropriate starting unit according to the magnitude of the voltage command value when the current is controlled to zero An apparatus can be realized. In addition, this configuration realizes a position sensorless motor control device that always selects the optimum starting part even if the induced voltage changes due to temperature change, etc., by selecting the starting part with a voltage command value equivalent to the induced voltage. can do. Furthermore, with this configuration, it is possible to realize a position sensorless motor control device that does not generate torque by controlling the current to zero during the startup period.
  In a seventh aspect of the position sensorless motor control device according to the present invention, the first starting means in the second aspect estimates an induced voltage based on the voltage command value, and calculates an angle and a speed of the rotor. You may comprise so that it may calculate.
  According to an eighth aspect of the position sensorless motor control device of the present invention, the second starting means according to the second aspect is configured to determine the angle and speed of the rotor based on a current response when a voltage pulse is applied. You may comprise so that it may calculate.
  In the position sensorless motor control apparatus according to the ninth aspect of the present invention, the current zero control unit (60) according to the second aspect is configured such that the current value (id, iq) flowing through the phase winding is zero. The position sensorless motor control device according to claim 2, wherein the voltage command value is generated by using proportional integral control so that the command value (id *, iq *) is obtained.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific examples which are one embodiment of a position sensorless motor control device according to the present invention will be described with reference to the accompanying drawings.
[0015]
Example 1
A position sensorless motor control apparatus that is Embodiment 1 of the present invention will be described below. The position sensorless motor control apparatus according to the first embodiment selects and operates one of the high-speed starter and the low-speed starter based on the magnitude of the voltage when the current is controlled to zero.
[0016]
First, the configuration of the position sensorless motor control apparatus according to the first embodiment will be described. FIG. 1 is a block diagram illustrating the configuration of the position sensorless motor control apparatus according to the first embodiment.
The brushless motor 1 includes a stator (not shown) made of an electromagnetic steel plate, phase windings 2u, 2v, and 2w made of coated copper wire through which a phase current flows and wound around the stator. And a rotor 3 arranged close to each other. Here, the phase windings 2u, 2v, 2w are Y-connected (connection in which one end of each phase winding 2u, 2v, 2w is connected at one point). The rotor 3 includes a rotor yoke 4 made of an electromagnetic steel plate, a permanent magnet 5 disposed inside the rotor yoke 4, and a shaft 6 having the same center of rotation as the rotor yoke 4. The rotor 3 is rotatably supported, and the rotor 3 is rotated by the interaction between the magnetic flux generated by the phase current and the magnetic flux generated by the permanent magnet 5.
[0017]
The position sensorless motor control apparatus according to the first embodiment detects an analog u-phase current value iua and an analog v-phase current value by detecting a phase current flowing in a microcomputer (hereinafter simply referred to as a microcomputer) 10 and phase windings 2u and 2v. current sensors 8u and 8v for outputting iva, and a drive unit 9 for controlling voltages applied to the phase windings 2u, 2v and 2w when switching command signals guh, ul, gvh, gvl, gwh and gwl are input. It has.
[0018]
An analog u-phase current value iua and an analog v-phase current value iva are input to the microcomputer 10, and an ADC (analog / digital converter) 11 u and an ADC 11 v that respectively output the u-phase current value iu and the v-phase current value iv. Is provided. Further, the microcomputer 10 receives the u-phase current value iu and the v-phase current value iv and outputs a u-phase voltage command value vu *, a v-phase voltage command value vv *, and a w-phase voltage command value vw *. PWM that outputs the switching signals guh, gul, gvh, gvl, gwh, and gwl when the control unit 12 receives the u-phase voltage command value vu *, the v-phase voltage command value vv *, and the w-phase voltage command value vw *. And a control unit 13.
[0019]
The motor control unit 12 is functionally composed of a selection unit 20, a high speed start unit 30, a low speed start unit 40, an operation unit 50, and a zero current control unit 60. The motor control unit 12 is composed of a CPU, a ROM, a RAM, a timer, a port, a bus connecting these, and the like in hardware.
[0020]
FIG. 2 is a circuit diagram illustrating a configuration of the drive unit 9 according to the first embodiment. As shown in FIG. 2, the drive unit 9 includes a power source 91, an upper IGBT (insulated gate bipolar bipolar transistor) whose collector is connected to the positive electrode of the power source 91, and whose emitter is connected to the phase windings 2u, 2v, and 2w, respectively. Transistors) 92u, 92v, 92w, and upper flywheel diodes 93u, 93v, 93w connected in reverse parallel to the upper IGBTs 92u, 92v, 92w, respectively. The drive unit 9 includes lower IGBTs 94u, 94v, and 94w whose collectors are connected to the stator windings 2u, 2v, and 2w and whose emitters are connected to the negative electrode of the power source 91, and the lower IGBTs 94u, 94v, The lower flywheel diodes 95u, 95v, 95w connected in reverse parallel to 94w, and the gate voltages and lower IGBTs 94u of the upper IGBTs 92u, 92v, 92w, respectively, based on the switching command signals guh, ul, gvh, gvl, gwh, gwl, respectively. , 94v and 94w are provided with a pre-drive device 96 for controlling the gate voltages.
[0021]
Next, the operation of the position sensorless motor control apparatus according to the first embodiment will be described.
The motor control unit 12 in the microcomputer 10 shown in FIG. 1 is a feature of the present invention, and performs start-up control and operation control of the brushless motor 5. Details of this operation will be described later.
[0022]
Current sensors 8u and 8v detect currents flowing through phase windings 2u and 2v, respectively, and generate analog u-phase current value iua and analog v-phase current value iva. The created analog u-phase current value iua and analog v-phase current value iva are input to the ADC 11u and the ADC 11v.
The ADC 11 u and ADC 11 v convert the analog u-phase current value iua and analog v-phase current value iva, which are analog values, into digital phase u-phase current value iu and v-phase current value iv, respectively.
[0023]
The PWM controller 13 in the microcomputer 10 performs pulse width modulation (PWM) on the u-phase voltage command value vu *, the v-phase voltage command value vv *, and the w-phase voltage command value vw *. The PWM control unit 13 generates a triangular wave having a certain set frequency and amplitude, and compares this triangular wave with the u-phase voltage command value vu *. When the u-phase voltage command value vu * is larger, the switching signal guh is set to H and the switching signal ul is set to L. On the other hand, when the u-phase voltage command value vu * is smaller, the switching signal guh is set to L and the switching signal ul is set to H. Note that when the states of the switching signals guh and ul transition, a short time is set for both of the switching signals guh and ul to be L (this short time is called a dead time). Similarly, for the v phase and the w phase, the switching signals gvh and gvl and the switching signals gwh and gwl are created based on the v phase voltage command value vv * and the w phase voltage command value vw *, respectively.
[0024]
The drive unit 9 applies the voltages represented by the switching signals guh, ul, gvh, gvl, gwh, gwl to the phase windings 2u, 2v, 2w.
The power source 91 supplies power to the drive unit 9.
The pre-drive unit 96 controls the gate voltage of the upper IGBT 92u so that the upper IGBT 92u is energized when the switching signal guh is H and the upper IGBT 92u is de-energized when the switching signal guh is L. On the other hand, the gate voltage of the lower IGBT 94u is controlled so that the lower IGBT 94u is energized when the switching signal ul is H and the lower IGBT 94u is not energized when the switching signal ul is L. Similarly, for the v-phase and the w-phase, the gate voltages of the upper IGBTs 92v and 92w and the lower IGBTs 94v and 94w are controlled based on the switching signals gvh, gvl, gwh, and gwl.
[0025]
Next, the principle of operation of the position sensorless motor control apparatus according to the first embodiment will be described.
First, it will be explained that it is necessary to switch the starting method depending on the magnitude of the induced voltage.
When the brushless motor 1 rotates, an induced voltage is induced. Therefore, at high speed, the induced voltage is used and the angle is estimated using the model equation of the motor.
On the other hand, since a sufficient induced voltage is not induced at a low speed as well as at a stop time, a method similar to that at a high speed cannot be used. The brushless motor 1 is a motor having a saliency in which a permanent magnet 5 is embedded in a rotor yoke 4. Therefore, when the rotor 3 rotates, the inductance changes. Therefore, the angle is estimated using the change in inductance.
Thus, it is necessary to switch the angle estimation method at the time of startup depending on the magnitude of the induced voltage. Therefore, when the induced voltage is large at the time of start-up, the start-up is performed by a high-speed method. On the other hand, when the induced voltage is small at the start-up, the start-up is performed by a low-speed method.
[0026]
Next, how to determine the magnitude of the induced voltage will be described.
First, the current command value is set to 0, and the voltage command value is controlled using proportional integral control so that the current becomes 0. Then, a voltage represented by this voltage command value is applied to the phase windings 2u, 2v, 2w by the drive unit 9.
Here, since the current is controlled to 0, the applied voltage is equal to the induced voltage. Therefore, the voltage command value when the current is controlled to 0 represents the induced voltage.
For these reasons, the starting method is switched depending on the magnitude of the voltage command value when the current is controlled to zero. That is, when the magnitude of the voltage command value is large, the system is activated by a high-speed method. On the other hand, when the magnitude of the voltage command value is small, the system is started by a low speed method.
[0027]
Next, the detail of operation | movement of the motor control part 12 of Example 1 is demonstrated.
First, the flow of operation will be described.
As shown in FIG. 1, first, the motor control unit 12 operates the selection unit 20. Next, the selection unit 20 selects which of the high-speed activation unit 30 and the low-speed activation unit 40 is to be operated. Next, the selected one of the high speed starter 30 and the low speed starter 40 is operated. Next, the operating unit 50 is operated. The zero current control unit 60 is executed in the selection unit 20 and the high speed start unit 30 or the low speed start unit 40.
[0028]
The operation when the motor control unit 12 specifically selects the high speed start unit 30 or the low speed start unit 40 will be described below.
First, when the high speed activation unit 30 is selected, the high speed activation unit 30 is selected by operating the selection unit 20. Next, the high speed start-up unit 30 is operated, and then the driving unit 50 is operated.
On the other hand, when the low speed activation unit 40 is selected, first, the selection unit 20 is operated to select the low speed activation unit 40. Next, the low speed starting unit 40 is operated, and then the driving unit 50 is operated.
[0029]
[Operation of Selection Unit 20]
Next, the operation of the selection unit 20 will be described.
The selection unit 20 controls the current to 0, and determines the magnitude of the voltage command value after a predetermined time has elapsed. Then, when the magnitude of the voltage command value is larger than the threshold value, the high speed starter 30 is selected. On the other hand, when the magnitude of the voltage command value is smaller than the threshold value, the low speed starter 40 is selected.
[0030]
FIG. 3 is a flowchart illustrating the operation of the selection unit 20 according to the first embodiment.
First, in step S201, the operation of the selection unit 20 is started.
Next, step S202 is executed. In step S202, the counter i is set to zero.
Next, step S203 is executed. In step S203, the zero current control unit 60 is operated. Details of this operation will be described later.
[0031]
Next, step S204 is executed. In step S204, 1 is added to the counter i.
Next, step S205 is executed. In step S205, when the counter i is smaller than a set value i020, next, step S203 is executed. In this way, the operation of the zero current control unit 60 in step S203 is repeated i020 times.
On the other hand, when the counter i is greater than or equal to a set value i020 in step S205, step S206 is executed. Thus, in step S205, the process branches depending on the value of the counter i.
[0032]
In step S206, a square value v2 of the voltage command value is created. As shown in the following equation (1), the square sum of the d-axis voltage command value vd * and the q-axis voltage command value vq * is defined as the square value v2 of the voltage command value. Here, the d-axis voltage command value vd * and the q-axis voltage command value vq * are obtained by the current zero control unit 60.
[0033]
v2 = vd * .vd * + vq * .vq * (1)
[0034]
Next, step S207 is executed.
In step S207, one of the activation units is selected depending on the magnitude of the square value v2 of the voltage command value. When the square value v2 of the voltage command value is larger than a set value v020, step S208 is executed to select the high-speed activation unit 30.
In step S207, when the square value v2 of the voltage command value is equal to or less than v020, step S209 is executed in order to select the low speed activation unit 40.
[0035]
In step S208, the operation of the selection unit 20 is terminated. Next, Step S301 is executed to start the operation of the high-speed startup unit 30.
On the other hand, in step S209, the operation of the selection unit 20 is terminated. Next, step S401 is executed to start the operation of the low speed activation unit 40.
[0036]
Next, the zero current control unit 60 of the motor control unit 12 in the first embodiment will be described.
The zero current control unit 60 creates a voltage command value for controlling the current to zero. The control routine is shared by setting the angle and the current command value to 0 and performing normal current control.
[0037]
[Configuration of Current Zero Control Unit 60]
First, the configuration of the zero current control unit 60 will be described.
FIG. 4 is a block diagram illustrating a configuration of the zero current control unit 60 according to the first embodiment. As shown in FIG. 4, the zero current control unit 60 generates a temporary angle creation unit 61 that outputs a temporary angle θt, and a current command value creation that outputs a d-axis current command value id * and a q-axis current command value iq *. Part 62. In addition, the zero current control unit 60 includes a three-phase two-phase conversion unit 63, a voltage command value creation unit 64, and a two-phase three-phase conversion unit 65.
The three-phase to two-phase converter 63 receives the angle θt, the u-phase current value iu, and the v-phase current value iv, and outputs a d-axis current value id and a q-axis current value iq. The voltage command value creation unit 64 receives the d-axis current command value id *, the q-axis current command value iq *, the d-axis current value id, and the q-axis current value iq, and receives the d-axis voltage command value vd * and the q-axis. The voltage command value vq * is output. The two-phase / three-phase converter 65 receives the temporary angle θt, the d-axis voltage command value vd *, and the q-axis voltage command value vq *, and inputs the u-phase voltage command value vu *, the v-phase voltage command value vv *, and the w-phase. The voltage command value vw * is output.
[0038]
[Operation of Zero Current Control Unit 60]
Next, the operation of the zero current control unit 60 will be described. The zero current control unit 60 operates each component in the order of a temporary angle creation unit 61, a current command value creation unit 62, a three-phase two-phase conversion unit 63, a voltage command value creation unit 64, and a two-phase three-phase conversion unit 65. Let
The temporary angle creation unit 61 sets the temporary angle θt to 0 as shown in the following formula (2). This is to share the normal current control and control routine. In the zero current control unit 60, the angle is always set to 0 °, and calculation is performed in the three-phase two-phase conversion unit 63 and the two-phase three-phase conversion unit 65 as described later.
The current command value creation unit 62 sets the d-axis current command value id * and the q-axis current command value iq * to 0 as in the following formulas (3) and (4).
[0039]
θt = 0 (2)
id * = 0 (3)
iq * = 0 (4)
[0040]
The three-phase to two-phase converter 63 converts a u-phase current value iu and a v-phase current value iv, which are values on a coordinate system fixed to the stator, into a d-axis current value id and a q-axis current. Convert to value iq. Usually, the angle of the rotor 3 is obtained, and the dq axis is converted as a coordinate system fixed to the permanent magnet 5 of the rotor 3, but here, the conversion is performed using the temporary angle θt = 0. Therefore, in this three-phase to two-phase conversion, the three-phase value is substantially only converted into the two-phase value. Specifically, conversion is performed as in the following formulas (5) and (6). In the following formula, the square root of a is expressed as √ (a).
[0041]
id = {√ (2)} · {iu · sin (θt + 60 °) + iv · sinθt}
... (5)
iq = {√ (2)} · {iu · cos (θt + 60 °) + iv · cosθt}
... (6)
[0042]
The voltage command value creation unit 64 controls the d-axis voltage command value vd * using proportional-integral control (PI control) so that the d-axis current value id becomes the d-axis current command value id *. Further, the q-axis voltage command value vq * is controlled using proportional integral control so that the q-axis current value iq becomes the q-axis current command value iq *.
As shown in the following equation (7), the difference between the d-axis current command value id * and the d-axis current value id multiplied by the proportional gain KPD and the difference between the d-axis current command value id * and the d-axis current value id The result obtained by adding the integrated value multiplied by the integral gain KID is defined as a d-axis voltage command value vd *.
Further, as shown in the following formula (8), the difference between the q-axis current command value iq * and the q-axis current value iq is multiplied by the proportional gain KPQ, and the q-axis current command value iq * and the q-axis current value iq The result obtained by adding the integral of the difference multiplied by the integral gain KIQ is defined as a q-axis voltage command value vq *.
[0043]
vd * = KPD · (id * −id) + KID · Σ (id * −id) (7)
vq * = KPQ · (iq * −iq) + KIQ · Σ (iq * −iq) (8)
[0044]
The two-phase / three-phase conversion unit 65 is a u-phase voltage command value that is a value on a coordinate system in which a d-axis voltage command value vd * and a q-axis voltage command value vq * that are values on the dq axis are fixed to the stator. It converts into vu *, v phase voltage command value vv *, and w phase voltage command value vw *. Usually, the angle of the rotor 3 is obtained, and the dq axis is converted as a coordinate system fixed to the permanent magnet 5 of the rotor 3, but here, the conversion is performed using the temporary angle θt = 0. Therefore, in this two-phase three-phase conversion, the two-phase value is only converted into a three-phase value. Specifically, conversion is performed as in the following formulas (9), (10), and (11).
[0045]
vu * = {√ (2/3)} · {vd * · cos θt−vq * · sin θt}
... (9)
vv * = {√ (2/3)} · {vd * · cos (θt−120 °)
−vq * · sin (θt−120 °)} (10)
vw * = {√ (2/3)} · {vd * · cos (θt + 120 °)
−vq * · sin (θt + 120 °)} (11)
[0046]
As described above, the zero current control unit 60 of the motor control unit 12 in the first embodiment controls the voltage command value so that the current becomes zero.
As described above, the selection unit 20 in the motor control unit 12 performs the above operation to select the high-speed starter 30 when the voltage command value is large, and to select the low speed when the voltage command value is small. The activation unit 40 is selected.
[0047]
[Operation of High-Speed Starter 30]
Next, the operation of the high speed starter 30 of the motor controller 12 in the first embodiment will be described.
The high-speed starter 30 is a start-up method for when the induced voltage is large, and creates an estimated angle θm and an estimated speed ωm based on a voltage command value when the current is controlled to 0.
FIG. 5 is a flowchart illustrating the operation of the high-speed activation unit 30 according to the first embodiment.
First, in step S301, the operation of the high-speed startup unit 30 is started. Next, step S302 is executed. In step S302, the counter i is set to zero.
[0048]
Next, step S303 is executed. In step S303, the zero current control unit 60 is operated. Since the current zero control unit 60 performs the above-described operation, the description thereof is omitted.
Next, step S304 is executed. In step S304, an estimated angle θm is created. The voltage command value when the current is controlled to 0 represents the induced voltage. FIG. 6 is a waveform diagram showing a change in the voltage command value when the current is controlled to be zero by the high speed starter 30 in the first embodiment. As shown in FIG. 6, when the angle θ (indicating the actual rotor angle) changes, the d-axis voltage command value vd * and the q-axis voltage command value vq * are shifted by 90 ° and change in a sine wave shape. Therefore, the angle is estimated from this relationship. Specifically, the estimated angle θm is obtained using an arctangent function atan (arc tangent) as in the following formula (12). Here, the estimated angle θm is shifted by 180 ° according to the sign of the d-axis voltage command value vd *.
[0049]
θm = atan (vd * / vq *) (when vd * ≦ 0)
θm = atan (vd * / vq *) + 180 ° (when vd *> 0)
(12)
[0050]
Next, step S305 is executed. In step S305, an estimated speed ωm is created. As shown in the following equation (13), the estimated angle θm is subtracted, and a value obtained by applying a low-pass filter is defined as an estimated speed ωm. In Equation (13), KW30 is a low-pass filter coefficient. The KW30 is a positive value of 1 or less. The smaller the KW30, the greater the action of the low-pass filter. Θm (i) is the estimated angle θm created at step S304 this time, and θm (i−1) is the estimated angle θm created at step S304 last time. Furthermore, ΔT30 is a cycle for operating step S305.
[0051]
ωm = KW30 · {θm (i) −θm (i−1)} / ΔT30
+ (1-KW30) · ωm (13)
[0052]
Next, step S306 is executed. In step S306, 1 is added to the counter i.
Next, step S307 is executed. In step S307, when the counter i is smaller than a set value i030, next, step S303 is executed. In this way, the operation of the zero current control unit 60 in step S303, the creation of the estimated angle θm in step S304, and the creation of the estimated speed ωm in step S305 are repeated i030 times.
On the other hand, when the counter i is equal to or larger than a set value i030 in step S307, step S308 is executed. Thus, in step S307, the process branches depending on the value of the counter i. In step S308, the operation of the high-speed activation unit 30 is terminated.
[0053]
Next, step S501 is executed and the operation of the driving unit 50 is started. The brushless motor 1 is driven by the method used in the former position sensorless motor control device described in the section of the prior art described above, using the estimated angle θm and the estimated speed ωm obtained in the high-speed starter 30 as initial values. .
[0054]
[Operation of Low-Speed Starter 40]
Next, the operation of the low speed activation unit 40 of the motor control unit 12 in the first embodiment will be described. The low-speed starter 40 is a start-up method for when the induced voltage is small, and creates the estimated angle θm and the estimated speed ωm by using the fact that the inductance changes as the rotor 2 rotates.
FIG. 7 is a flowchart illustrating the operation of the low speed activation unit 40 according to the first embodiment.
First, in step S401, the operation of the low speed activation unit 40 starts. Next, step S402 is executed. In step S402, the counter i is set to zero.
Next, step S403 is executed. In step S403, the counter j is set to zero. Next, step S404 is executed. In step S404, the zero current control unit 60 is operated. Since the zero current control unit 60 performs the same operation as described above, the description thereof is omitted.
[0055]
Next, step S405 is executed. In step S405, 1 is added to the counter j.
Next, step S406 is executed. In step S406, when the counter j is smaller than a set value j040, next, step S404 is executed. In this way, the operation of the zero current control unit 60 in step S404 is repeated j040 times.
On the other hand, when the counter j is greater than or equal to a certain set value j040 in step S406, step S407 is executed. Thus, in step S406, the process branches depending on the value of the counter j.
In step S407, an estimated angle θm is created. Details of the operation in step S407 will be described later.
[0056]
Next, in step S408, an estimated speed ωm is created. As shown in the following equation (14), the estimated angle θm is subtracted, and a value obtained by applying a low-pass filter is defined as an estimated speed ωm. In Equation (14), KW40 is a low-pass filter coefficient. This KW40 is a positive value of 1 or less, and the smaller the KW40, the greater the action of the low-pass filter. Θm (i) is the estimated angle θm created at step S407 this time, and θm (i−1) is the estimated angle θm created last time at step S407. Furthermore, ΔT40 is a cycle for operating step S408.
[0057]
ωm = KW40 · {θm (i) −θm (i−1)} / ΔT40
+ (1-KW40) · ωm (14)
[0058]
Next, step S409 is executed. In step S409, 1 is added to the counter i.
Next, step S410 is executed. In step S410, when the counter i is smaller than a set value i040, next, step S403 is executed. In this way, the creation of the estimated angle θm in step S407 and the creation of the estimated speed ωm in step S408 are repeated i040 times.
On the other hand, when the counter i is greater than or equal to a set value i040 in step S410, step S411 is executed. Thus, in step S410, the process branches depending on the value of the counter i.
In step S411, the polarity is determined. Details of the operation in step S411 will be described later.
[0059]
Next, step S412 is executed. In step S412, the operation of the low speed activation unit 40 is terminated.
Next, step S502 is executed and the operation of the driving unit 50 is started. The brushless motor 1 is driven by the method used in the latter position sensorless motor control device described in the section of the prior art described above, using the estimated angle θm and the estimated speed ωm obtained in the low speed starting unit 40 as initial values. .
[0060]
Next, the operation of step S407 for creating the estimated angle θm will be described.
First, the principle of the operation in step S407 for creating the estimated angle θm will be described.
FIG. 8 is a waveform diagram showing the relationship between the voltage pulse and the current response in the first embodiment. Since the induced voltage is small, the d-axis voltage command value vd * and the q-axis voltage command value vq * are small. Here, the pulse voltage is superimposed on the d-axis voltage command value vd *. This superposition changes the d-axis current value id by the d-axis current response Δid in response to the pulse voltage. Further, the q-axis current value iq changes by the q-axis current response Δiq. Note that the angle in the calculation is fixed as the temporary angle θt = 0.
[0061]
FIG. 9 is a waveform diagram showing the relationship between the angle and the current response in the first embodiment. Since the brushless motor 1 has saliency, when the angle θ (indicating the actual rotor angle) changes, the inductance changes. Therefore, when the angle θ changes, the d-axis current response Δid and the q-axis current response Δiq change. The estimated angle θm is obtained from this relationship. Since the change in inductance has a period of 180 °, the estimated angle θm is only obtained in the range of 0 to 180 °.
[0062]
  Next, details of the operation in step S407 for creating the estimated angle θm will be described.
  FIG. 10 is a flowchart showing the operation of step S407 for creating the estimated angle θm in the low speed activation unit 40 according to the first embodiment.
  First, in step S701, the operation of step S407 for creating the estimated angle θm is started.
  Next, step S702 is executed. In step S702, the temporary angle θt is set to zero. Next, step S703 is executed. In step S703, the positive pulse portion of the voltage pulse is applied, and this state is held for a set time. As in the following formulas (15), (16), and (17),d-axis voltage command value vd *Voltage pulses are superimposed on the two-phase and three-phase converted to u-phase voltage command value vu *, v-phase voltage command value vv *, and w-phase voltage command value vw *. This state is held for a set time.
[0063]
vu * = {√ (2/3)} · {(vd * + ΔV) · cos θt
−vq * · sin θt} (15)
vv * = {√ (2/3)} · {(vd * + ΔV) · cos (θt−120 °)
−vq * · sin (θt−120 °)} (16)
vw * = {√ (2/3)} · {(vd * + ΔV) · cos (θt + 120 °)
-Vq * · sin (θt + 120 °)} (17)
[0064]
Step S704 is executed after a set time has elapsed since the u-phase voltage command value vu *, the v-phase voltage command value vv *, and the w-phase voltage command value vw * have been set.
In step S704, the u-phase current value iu and the v-phase current value iv are stored as a u-phase current response Δiu and a v-phase current response Δiv, respectively.
[0065]
  Next, step S705 is executed. In step S705, the negative pulse portion of the voltage pulse is applied, and this state is held for a set time. As in the following formulas (18), (19), (20),d-axis voltage command value vd *Voltage pulses are superimposed on the two-phase and three-phase converted to u-phase voltage command value vu *, v-phase voltage command value vv *, and w-phase voltage command value vw *. This state is held for a set time.
[0066]
vu * = {√ (2/3)} · {(vd * −ΔV) · cos θt
−vq * · sin θt} (18)
vv * = {√ (2/3)} · {(vd * −ΔV) · cos (θt−120 °)
−vq * · sin (θt−120 °)} (19)
vw * = {√ (2/3)} · {(vd * −ΔV) · cos (θt + 120 °)
−vq * · sin (θt + 120 °)} (20)
[0067]
Thereafter, the u-phase voltage command value vu *, the v-phase voltage command value vv *, and the w-phase voltage command value vw * are set to the voltage pulses set by the above-described equations (9), (10), and (11), respectively. Return to the value before applying.
Next, step S706 is executed. In step S706, the u-phase current response Δiu and the v-phase current response Δiv that are values on the coordinate system fixed to the stator are converted into a d-axis current response Δid and a q-axis current response Δiq that are values on the dq axis. To do. Here, the q-axis current response Δiq is further multiplied by −1 after the conversion. Usually, the angle of the rotor 3 is obtained, and the dq axis is converted as a coordinate system fixed to the permanent magnet 5 of the rotor 3. However, here, the temporary angle θt = 0 is converted. Therefore, in this three-phase to two-phase conversion, the three-phase value is substantially only converted into the two-phase value. Specifically, conversion is performed as shown in the following formulas (21) and (22).
[0068]
Δid = {√ (2)} · {Δiu · sin (θt + 60 °)
+ Δiv · sin θt} (21)
Δiq = − {√ (2)} · {Δiu · cos (θt + 60 °)
+ Δiv · cos θt} (22)
[0069]
Next, step S707 is executed. In step S707, the estimated angle θm is calculated. The relationship shown in FIG. 9 is related to the angle θ (the actual angle of the rotor 3) and the current response. Therefore, the estimated angle θm is obtained using an arctangent function atan (arc tangent) as shown in the following equation (23). Here, the range of the estimated angle θm is limited to 0 to 180 °.
[0070]
θm = atan (Δiq / Δid) / 2 (when Δiq ≧ 0)
θm = {atan (Δiq / Δid) / 2} + 90 ° (when Δiq <0)
(23)
[0071]
Next, step S708 is executed. In step S708, the operation of step S407 for creating the estimated angle θm is terminated.
[0072]
Next, the operation of step S411 for determining polarity will be described.
First, a voltage pulse is applied to the position of the estimated angle θm and a position shifted from this position by 180 °. By applying the voltage pulse in this way, the magnitude of the current response at the two positions differs due to the influence of magnetic saturation. Therefore, the polarity is determined from this size.
[0073]
FIG. 11 is a flowchart illustrating the operation in step S411 for determining the polarity in the low speed activation unit 40 according to the first embodiment.
In step S801, the operation of step S411 for determining polarity is started.
Next, step S811 is executed. In step S811, the counter i is set to zero. Next, step S812 is executed. In step S812, the zero current control unit 60 is operated. Since this zero current controller 60 operates in the same manner as described above, its description is omitted.
[0074]
Next, step S813 is executed. In step S813, 1 is added to the counter i.
Next, step S814 is executed. In step S814, when the counter i is smaller than a set value i080, next, step S812 is executed. In this way, the operation of the zero current control unit 60 in step S812 is repeated i080 times.
On the other hand, when the counter i is greater than or equal to a set value i080 in step S814, step S821 is executed. Thus, in step S814, the process branches according to the value of the counter i.
In step S821, the provisional angle θt is set as the estimated angle θm. Next, step S822 is executed. In steps S822 to S824, the same contents as in steps S703 to S705 described above are executed. Therefore, the description of the execution contents is omitted here by using the description from step S703 to step S705 described above.
[0075]
Next, step S825 is executed. In step S825, the u-phase current response Δiu and the v-phase current response Δiv that are values on the coordinate system fixed to the stator are converted into a d-axis current response Δid that is a value on the dq axis. This conversion is the same as that performed in step S706 described above, and a description thereof will be omitted.
[0076]
Next, step S826 is executed. In step S826, the d-axis current response Δid is stored as the first d-axis current response Δid1. Next, step S831 is executed. In step S831, the counter i is set to zero. Next, step S832 is executed. In step S832, the zero current control unit 60 is operated. Since the operation of the zero current control unit 60 is the same as that described above, the description thereof is omitted.
[0077]
Next, step S833 is executed. In step S833, 1 is added to the counter i.
Next, step S834 is executed. In step S834, when the counter i is smaller than a set value i080, next, step S832 is executed. In this way, the operation of the zero current control unit 60 in step S832 is repeated i080 times.
[0078]
On the other hand, in step S834, when the counter i is greater than or equal to a set value i080, step S841 is executed. Thus, in step S834, the process branches depending on the value of the counter i.
In step S841, the provisional angle θt is set to the estimated angle θm + 180 °.
Next, step S842 is executed. In steps S842 to S845, the same contents as in steps S822 to S825 described above are executed. For this reason, description of the execution contents is omitted.
[0079]
In step S846, the d-axis current response Δid is stored as the second d-axis current response Δid2. Next, step S851 is executed. In step S851, the first d-axis current response Δid1 is compared with the second d-axis current response Δid2, and the process branches. When the first d-axis current response Δid1 is greater than or equal to the second d-axis current response Δid2, step S852 is executed. In step S852, the estimated angle θm is set as the estimated angle θm. Next, step S861 is executed.
[0080]
On the other hand, when the first d-axis current response Δid1 is less than the second d-axis current response Δid2 in step S851, step S853 is executed. In step S853, the estimated angle θm is set to the estimated angle θm + 180 °. Next, step S861 is executed.
In step S861, the operation of step S411 for determining polarity is terminated.
As described above, the position sensorless motor control apparatus according to the first embodiment is configured and operated, so that the brushless motor 5 can be smoothly started even when the rotor 2 is rotating.
[0081]
Next, the effect of the position sensorless motor control apparatus according to the first embodiment will be described.
In the conventional position sensorless motor control device, as described in the above-mentioned section of the prior art, the rotor 3 is stopped and started by the method used in the latter conventional position sensorless motor control device. And it switched to the system currently used with the former conventional position sensorless motor control apparatus suitably, and accelerated to high speed.
Therefore, when the rotor 3 is rotating immediately before starting, if it is stopped at the time of starting as described above, if it is started by the method used in the latter conventional position sensorless motor control device, it cannot start smoothly. was there.
[0082]
The position sensorless motor control apparatus according to the first embodiment first controls the current to zero. Since the voltage command value at this time is equivalent to the induced voltage, the starting method is selected according to the magnitude of the voltage command value. That is, when the magnitude of the voltage command value is large, the high-speed starter that estimates the angle and speed based on the voltage command value is operated. On the other hand, when the magnitude of the voltage command value is small, the low-speed starter that estimates the angle and speed using the change in inductance accompanying the rotation of the rotor 3 is operated.
As described above, the position sensorless motor control apparatus according to the first embodiment selects and operates an appropriate starter according to the magnitude of the voltage command value when the current is controlled to zero, so that the rotor 3 rotates. Smooth start-up of the brushless motor 1 is realized.
[0083]
Next, consider selecting an activation method according to the number of rotations. The induced voltage has individual differences due to manufacturing variations of the brushless motor 1. Further, when the temperature of the permanent magnet 5 changes, the magnitude of the induced voltage changes. For this reason, when selecting an activation method based on the number of rotations, the optimum activation unit cannot always be selected.
The position sensorless motor control apparatus according to the first embodiment first controls the current to zero. Since the voltage command value at this time is equivalent to the induced voltage, the starting method is selected according to the magnitude of the voltage command value.
As described above, the position sensorless motor control apparatus according to the first embodiment always selects the starting unit based on the voltage command value equivalent to the induced voltage, so that even if the induced voltage changes due to a temperature change or the like, Realize the selection.
[0084]
Next, let us consider flowing a current during the startup period. During the startup period, the angle cannot be estimated accurately. For this reason, even if a certain current command value is given to cause a certain current to flow, the current cannot be caused to flow according to this current command value. For this reason, if a current is passed during the start-up period, an improper current flows, and vibration and noise may occur.
In the position sensorless motor control apparatus according to the first embodiment, the selection unit 20 controls the current to zero and does not generate torque. Further, the current is controlled to zero in the high-speed starter 30 so that no torque is generated. Similarly, the current is controlled to zero in the low speed starter 40, and no torque is generated. As described above, the position sensorless motor control apparatus according to the first embodiment has a configuration in which torque is not generated by controlling the current to zero during the startup period. For this reason, the position sensorless motor control apparatus according to the first embodiment does not cause an abnormal current to flow even when a current is passed during the start-up period, and the occurrence of vibrations and noise is prevented.
[0085]
Example 2
Next, a position sensorless motor control apparatus according to a second embodiment of the present invention will be described with reference to the accompanying drawings.
In the above-described position sensorless motor control apparatus of the first embodiment, the low speed starter 40 estimates the angle and the speed by using the change in inductance accompanying the rotation of the rotor 3. In the position sensorless motor control apparatus according to the second embodiment, the low speed starter 2040 estimates the angle and the speed by using the saturation of the magnetic flux.
The position sensorless motor according to the first embodiment is configured to control an embedded magnet type motor in which the permanent magnet 5 is embedded in the rotor yoke 4. The position sensorless motor according to the second embodiment controls a surface magnet type motor in which a permanent magnet 2005 is disposed on the surface of a rotor yoke 2004.
[0086]
Hereinafter, the configuration of the position sensorless motor control apparatus according to the second embodiment will be described. FIG. 12 is a block diagram illustrating a configuration of the position sensorless motor control device according to the second embodiment.
The brushless motor 2001 according to the second embodiment includes a stator (not shown) made of an electromagnetic steel plate, phase windings 2u, 2v, 2w wound on a stator made of coated copper wire and flowing a phase current, A rotor 2003 is provided so as to face and be close to the stator. The phase windings 2u, 2v, 2w are Y-connected. The rotor 2003 includes a rotor yoke 2004 made of an electromagnetic steel plate, a permanent magnet 2005 disposed on the surface of the rotor yoke 2004, and a shaft 2006 having the same rotation center as the rotor yoke 2004. The rotor 2003 is rotatably supported, and the rotor 2003 is rotated by the interaction between the magnetic flux generated by the phase current and the magnetic flux generated by the permanent magnet 2005.
[0087]
Of the configurations included in the position sensorless motor control device of the second embodiment, the microcomputer 2010 is different from the first embodiment. Among the configurations included in the microcomputer 2010, the motor control unit 2012 is different from the first embodiment. Of the configurations included in the motor control unit 2012, the low-speed activation unit 2040 is different from the first embodiment. Since the other configuration is the same as that of the first embodiment, the description of the configuration and operation thereof is omitted in the second embodiment by using the description of the first embodiment.
[0088]
Next, the operation of the low speed activation unit 2040 in the second embodiment will be described.
The low-speed starter 2040 is a start-up method for when the induced voltage is small, and creates the estimated angle θm and the estimated speed ωm using the saturation of the magnetic flux.
First, the principle of operation of the low speed activation unit 2040 will be described.
As shown in FIG. 8, since the induced voltage is small, the d-axis voltage command value vd * and the q-axis voltage command value vq * are small. Here, when a pulse voltage is superimposed on the d-axis voltage command value, the d-axis current value id changes by the d-axis current response Δid in response to the voltage pulse. Note that the angle in the calculation is fixed as the temporary angle θt = 0.
[0089]
FIG. 13 is a waveform diagram showing the relationship between the angle (horizontal axis) and the current response (vertical axis) in Example 2. When the angle θ (the actual angle of the rotor 2003) is 0, a magnetic flux is generated in a direction in which the magnetic flux generated by the permanent magnet 2005 is strengthened by a voltage pulse. When magnetic flux is generated in this way, magnetic flux saturation occurs in the stator, and the current response increases. Therefore, when the current response becomes the largest, the estimated angle θm = 0 may be set.
[0090]
Next, details of the operation of the low-speed activation unit 2040 will be described.
FIG. 14 is a flowchart illustrating the operation of the low speed activation unit 2040 according to the second embodiment.
In step S2401, the operation of the low speed activation unit 2040 is started.
Next, step S2402 is executed. In step S2402, the value of the counter i is set to zero. Next, step S2403 is executed. In step S2403, the value of the counter j is set to zero.
Next, step S2404 is executed. In step S2404, the zero current control unit 60 is operated. Since the operation of the zero current control unit 60 is the same as the operation of the zero current control unit 60 in the first embodiment, the description thereof is omitted.
[0091]
Next, step S2405 is executed. In step S2405, 1 is added to the counter j.
Next, step S2406 is executed. In step S2406, when the counter j is smaller than a certain set value j02040, next, step S2404 is executed. In this way, the operation of the zero current control unit 60 in step S2404 is repeated j02040 times.
On the other hand, when the counter j is greater than or equal to a set value j02040 in step S2406, step S2407 is executed. Thus, in step S2406, the process branches depending on the value of the counter j.
From step S2407 to step S2410, the same content as the operation from step S702 to step S705 in the first embodiment shown in FIG. 10 is executed. For this reason, description of the execution contents is omitted.
[0092]
In step S2411, the u-phase current response Δiu and the v-phase current response Δiv that are values on the coordinate system fixed to the stator are converted into a d-axis current response Δid that is a value on the dq axis. This conversion is the same as the operation in step S825 in the first embodiment, and a description thereof will be omitted.
Next, step S2412 is executed. In step S2412, it is determined whether or not the d-axis current response Δid is maximal. When the d-axis current response Δid is maximum, step S2413 is executed. On the other hand, when the d-axis current response Δid is not maximal, step S2403 is executed. When the slope of the d-axis current response Δid changes from positive to negative, it is determined that the d-axis current response Δid is maximal. In this way, the calculation of the d-axis current response Δid in step S2411 is repeated until the d-axis current response Δid reaches a maximum.
[0093]
In step S2413, the estimated angle θm is set to zero. Next, step S2414 is executed. In step S2414, an estimated speed ωm is created. Step S2414 is executed every 360 ° in electrical angle. Therefore, the speed is 360 ° divided by the time interval at which step S2414 is executed. Then, an estimated speed ωm is obtained by applying a low-pass filter to the division result. Specifically, the following equation (24) is used. In Equation (24), KW2040 is a low-pass filter coefficient. This KW2040 is a positive value of 1 or less, and the smaller the value, the greater the action of the low-pass filter. ΔT2040 is the time from when the previous step S2414 was executed until this time step S2414 is executed.
[0094]
ωm = KW2040 · 360 ° / ΔT2040
+ (1-KW2040) · ωm (24)
[0095]
Next, step S2415 is executed. In step S2415, 1 is added to the counter i.
Next, step S2416 is executed. In step S2416, when the counter i is smaller than a set value i02040, next, step S2403 is executed. In this manner, the creation of the estimated angle θm in step S2413 and the creation of the estimated speed ωm in step S2414 are repeated i02040 times.
On the other hand, if it is determined in step S2416 that the counter i is greater than or equal to a set value i02040, step S2417 is executed. Thus, in step S2416, the process branches depending on the value of the counter i. In step S2417, the operation of the low speed activation unit 2040 is terminated.
[0096]
Next, step S503 is performed and the operation | movement of the driving | operation part 50 is started. For example, the brushless motor 2001 is driven by the method used in the position sensorless motor control device disclosed in Japanese Patent Application No. 10-329049, using the estimated angle θm and the estimated speed ωm obtained by the low speed starting unit 2040 as initial values. To do.
[0097]
As described above, by configuring and operating the position sensorless motor control apparatus according to the second embodiment, the brushless motor 2001 can be smoothly started even when the rotor 2003 is rotating at the time of startup.
Further, the position sensorless motor control device of the second embodiment has the same operation as that of the position sensorless motor control device of the first embodiment, and can achieve the same effects as those of the first embodiment.
[0098]
In the first embodiment, an example of a configuration in which the embedded magnet type motor (brushless motor 1) is controlled, and in the second embodiment, the surface magnet type motor (brushless motor 2001) is controlled. However, the configuration may be such that the surface magnet type motor is controlled by the method of the first embodiment and the embedded magnet type motor is controlled by the method of the second embodiment.
In general, the surface magnet type motor has a small change in inductance accompanying the rotation of the rotor. However, some specific surface magnet type motors are relatively rich in inductance changes. In such a surface magnet type motor, the system of the first embodiment is more effective than the system of the second embodiment.
In general, an embedded magnet type motor has a large change in inductance with the rotation of the rotor. However, there are certain embedded magnet type motors in which the change in inductance is poor. In such an embedded magnet type motor, the method of the second embodiment is more effective than the method of the first embodiment.
[0099]
In the low speed start-up units 40 and 2040 of the above-described embodiment, a method of applying a voltage pulse is used. However, the present invention is not limited to this method. For example, a method may be used in which a high frequency voltage or a high frequency current is superimposed and the angle is estimated based on the current response or voltage response. Further, the angle may be estimated from the current response in the PWM carrier.
Similarly, the high-speed start-up unit 30 of the above-described embodiment is not limited to the method of the first embodiment, and any configuration may be used as long as the current is controlled and the voltage command value at this time is used. Included in the invention.
[0100]
Furthermore, the present invention is not limited to the case of normal rotation at the time of activation, and may be the case of reverse rotation at the time of activation.
When rotating at a low speed in the reverse direction at the time of startup, the position sensorless motor control device of the present invention operates as follows in order to rotate at a high speed in the normal direction.
First, the selection unit 20 operates to select the low-speed activation units 40 and 2040, and the low-speed activation units 40 and 2040 operate. The low speed activation units 40 and 2040 create an estimated angle θm and a negative estimated speed ωm, and the driving unit 50 operates based on these. Then, the driving unit 50 performs angle estimation for low speed, and generates a positive torque. Eventually, what was rotating in the reverse direction starts to rotate in the normal direction. Furthermore, the angle estimation for high speed is performed as appropriate to accelerate to high speed.
[0101]
On the other hand, the position sensorless motor control device of the present invention operates as follows in order to rotate at high speed in the forward direction when rotating at high speed in the reverse direction at startup.
First, the selection unit 20 operates to select the high-speed activation unit 30 and operate the high-speed activation unit 30. The high-speed activation unit 30 creates an estimated angle θm and a negative estimated speed ωm, and the driving unit 50 operates based on these. Then, the driving unit 50 performs angle estimation for high speed and generates torque in a positive direction. Eventually, the vehicle is decelerated, the angle estimation for low speed is performed as appropriate, and the object that has been rotated in the reverse direction starts to rotate in the normal direction. Furthermore, the angle estimation for high speed is performed as appropriate to accelerate to high speed.
In the current zero control unit 60, the temporary angle θt is set to 0, but other angles may be used. In this case, it is necessary to appropriately change the creation of the estimated angle θm in step S304 of the high speed activation unit 30.
[0102]
【The invention's effect】
As described above, according to the present invention, the brushless motor can be smoothly operated even when the rotor is rotating by selecting and operating an appropriate starting unit according to the magnitude of the voltage command value when the current is controlled to zero. It is possible to realize a position sensorless motor control device that is activated at the same time.
Further, according to the present invention, the position sensorless motor control device that always selects the optimum starting part even if the induced voltage changes due to a temperature change or the like by selecting the starting part based on a voltage command value equivalent to the induced voltage. Can be realized.
In addition, according to the present invention, it is possible to realize a position sensorless motor control device that does not generate torque and can be smoothly started by controlling the current to zero during the startup period.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a position sensorless motor control apparatus according to a first embodiment of the present invention.
FIG. 2 is a circuit diagram illustrating a configuration of a drive unit according to the first embodiment.
FIG. 3 is a flowchart illustrating an operation of a selection unit according to the first embodiment.
FIG. 4 is a block diagram illustrating a configuration of a zero current control unit according to the first embodiment.
FIG. 5 is a flowchart illustrating the operation of the high-speed activation unit according to the first embodiment.
6 is a waveform diagram showing a change in voltage command value when the current is controlled to be zero by the high-speed start-up unit in Embodiment 1. FIG.
FIG. 7 is a flowchart illustrating the operation of the low speed activation unit according to the first embodiment.
FIG. 8 is a waveform diagram showing the relationship between voltage pulses and current response in Example 1.
9 is a waveform diagram showing the relationship between the angle and the current response in Example 1. FIG.
FIG. 10 is a flowchart illustrating an operation of a step of creating an estimated angle in the low speed activation unit according to the first embodiment.
FIG. 11 is a flowchart showing the operation of the step of determining the polarity in the low-speed startup unit in the first embodiment.
FIG. 12 is a block diagram illustrating a configuration of a position sensorless motor control device according to a second embodiment of the present invention.
13 is a waveform chart showing the relationship between the angle and the current response in Example 2. FIG.
FIG. 14 is a flowchart illustrating the operation of the low speed activation unit according to the second embodiment.
[Explanation of symbols]
1 Brushless motor
2u, 2v, 2w phase winding
3 Rotor
5 Permanent magnet
8u, 8v current sensor
9 Drive unit
10 Microcomputer
12 Motor controller
20 Selector
30 Starter for high speed
40 Low speed starter

Claims (9)

Position sensorless motor control apparatus for controlling a brushless motor having a rotor in which a permanent magnet is disposed and rotatably supported, a stator disposed in the vicinity of the rotor, and a phase winding wound around the stator Because
Drive means for applying a voltage based on a voltage command value representing a command value of the voltage applied to the phase winding;
A plurality of activation means for activating said brushless motor,
A current zero control unit for creating a voltage command value for controlling the current flowing in the phase winding to zero;
Selecting means for selecting one starting means from the plurality of starting means based on the voltage command value created by the current zero control unit ,
A position sensorless motor control device configured to calculate an angle and a speed of the rotor based on the voltage command value that makes the current flowing through the phase winding zero in the starting means selected by the selection means . The plurality of activation means includes first activation means for activating the brushless motor at a high speed, and second activation means for activating the brushless motor at a low speed ,
It said selection means, the phase the voltage command value when controlling the current to zero flowing through the windings to select the first activating means is greater than the threshold, to zero the current flowing in the phase windings The position sensorless motor control device according to claim 1, wherein the second starter is selected when the voltage command value when controlled is smaller than a threshold value. The position sensorless motor control device according to claim 2 , wherein the second activation unit is configured to use a change in inductance accompanying rotation of a rotor of the brushless motor. The position sensorless motor control device according to claim 2 , wherein the second activation unit is configured to use magnetic flux saturation. The first activation means controls said voltage command value to zero the current flowing through the phase windings, calculates the angle and speed of the rotor based on the voltage command value,
It said second activation means, the phase current flowing in the windings is controlled to be zero, by utilizing the change in inductance caused by the rotation of the rotor is configured for calculating the angle and speed of the rotor The position sensorless motor control device according to claim 2 . The first activation means controls said voltage command value to zero the current flowing through the phase windings, calculates the angle and speed of the rotor based on the voltage command value,
Said second activation means controls so as to zero the current flowing through the phase windings, according to claim 2 configured to utilize the magnetic flux saturation calculating the angle and speed of the rotor position sensorless motor control apparatus. The position sensorless motor control device according to claim 2, wherein the first starting unit is configured to estimate an induced voltage based on the voltage command value and to calculate an angle and a speed of the rotor. The position sensorless motor control device according to claim 2, wherein the second starting unit is configured to calculate an angle and a speed of the rotor based on a current response when a voltage pulse is applied. 3. The position sensorless device according to claim 2, wherein the current zero control unit is configured to create a voltage command value using proportional integral control so that a current value flowing through the phase winding becomes a current command value indicating zero. Motor control device.

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