JP4455960B2 - DC brushless motor control device - Google Patents

Description

  The present invention relates to a control device for a DC brushless motor having a function of detecting a rotor angle of a DC brushless motor without using a position detection sensor.

  In order to obtain a desired torque by driving the DC brushless motor, it is necessary to apply a voltage to the armature at an appropriate phase corresponding to the electrical angle of the rotor having magnetic poles (hereinafter referred to as the rotor angle). Therefore, a DC brushless motor is generally provided with a position detection sensor that detects a rotor angle.

  However, when the position detection sensor is provided, it is necessary to provide not only the position detection sensor but also a circuit for inputting a detection signal output from the position detection sensor on the driving device side of the DC brushless motor. Wiring between the position detection sensor and the driving device is also required. Therefore, a method for detecting the rotor angle without using the position detection sensor has been proposed in order to reduce the cost of the DC brushless motor and the driving device by omitting the position detection sensor.

As such a method, the rotor angle is detected at a cycle of 180 degrees based on the detected value of the armature current when the high-frequency voltage for detecting the rotor angle is superimposed on the driving voltage of the DC brushless motor, and the so-called dq coordinate is used. The rotor angle is detected at a period of 360 degrees by detecting the direction of the magnetic pole of the rotor based on the detected value of the armature current when the magnetic pole direction discrimination current is supplied to the q-axis armature (the armature in the field direction). A method has been proposed (see, for example, Patent Document 1).
JP 2002-320398 A

  The rotor magnetic pole direction discrimination processing according to the background art method described above may be performed once at the start of rotor angle detection. In order to increase the responsiveness of the change in the armature current to the supply of the magnetic pole direction discrimination current to the q-axis armature and reduce the time required to determine the rotor magnetic pole direction, the command value for the q-axis armature is It is conceivable to set a large gain in feedback control for following the current. However, when the present inventors perform feedback control of torque current that causes the actual current to follow the command value for the d-axis armature of the DC brushless motor by setting the gain to be large in this way, the rotor magnet is reduced. It was found that magnetism might be promoted.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a DC brushless motor control device that reduces the time required for rotor magnetic pole direction discrimination processing and suppresses the demagnetization of the rotor magnet when torque current feedback control is executed. .

The present invention has been made in order to achieve the above object, and a DC brushless motor has a q-axis armature on the q-axis which is the magnetic flux direction of the field of the motor, and a d-axis orthogonal to the q-axis. The current detection means for detecting the current flowing through the armature of the motor, the current value detected by the current detection means, and the rotor angle of the motor An actual current calculation means for calculating a q-axis actual current flowing in the q-axis armature and a d-axis actual current flowing in the d-axis armature, and a q-axis which is a command value of the current flowing in the q-axis armature Q-axis current deviation which is a deviation between the command current and the q-axis actual current, and d-axis current deviation which is a deviation between the d-axis command current which is a command value of the current flowing through the d-axis armature and the d-axis actual current Of the voltage applied to the d-axis armature A command voltage determining means for determining a d-axis command voltage which is a value and a q-axis command voltage which is a command value of a voltage to be applied to the q-axis armature, and the d-axis command voltage and the q-axis command voltage Determining a driving voltage to be applied to the armature of the motor, and energizing control means for controlling energization of the motor; and when the rotational speed of the motor is less than a predetermined value, the driving voltage is used for detecting the rotor angle. A rotor angle detection process for detecting the rotor angle of the motor at a cycle of 180 degrees based on the current value detected by the current detection means when the high frequency voltage is superimposed, and the magnetic pole direction discrimination current in the q-axis command current Is performed on the basis of the current value detected by the current detection means when the motor is superimposed, and the rotor magnetic pole direction determination process is performed to determine the magnetic pole direction of the rotor of the motor. Detected at 60 ° period, when the rotational speed of the motor is the predetermined value or more, without the superposition of the high frequency voltage, for detecting the rotor angle of the motor by back electromotive force generated in the armature of the motor The present invention relates to an improvement in a control device for a DC brushless motor including rotor angle detection means for performing rotor angle detection processing for a high rotation range .

When the rotor magnetic pole direction determination process is executed, the command voltage determination unit determines the q-axis command voltage by multiplying the q-axis current deviation by a first gain, and the rotor magnetic pole direction determination process. When the rotor angle detection process for the low rotation region is executed after the application of the d-axis command current is started and the d-axis command current is started , the q-axis current deviation is smaller than the first gain. The q-axis command voltage is determined by multiplying the gain.

  According to the present invention, the command voltage generating means switches the gain used when determining the q-axis command voltage between the first gain and the second gain. When the rotor magnetic pole direction discrimination processing is executed, when the magnetic pole discrimination current is superimposed by determining the q-axis command voltage using the first gain set relatively large The response time of the change in the armature current of the motor can be improved, and the time required for the rotor magnetic pole direction discrimination processing can be shortened. On the other hand, after the application of the d-axis command voltage is started, the command voltage generation means determines the q-axis command voltage using the second gain set relatively small, so that the rotor When a detection error of the rotor angle by the angle detection means occurs, the level of the q-axis command voltage determined based on the detection error is suppressed. Therefore, it is possible to prevent the rotor magnet of the motor from being demagnetized by applying a drive voltage corresponding to the q-axis command voltage.

  The motor is mounted on a vehicle that uses the motor as a source of driving force for the drive shaft, and at the start of operation of the vehicle, the rotor angle detection means performs the rotor angle estimation processing and the rotor magnetic pole direction detection processing. After the rotor angle of the motor can be detected at a cycle of 360 degrees, application of the d-axis command current for controlling the torque current of the motor is started.

  According to the present invention, by switching the first gain and the second gain described above to shorten the time required for the rotor magnetic pole direction discrimination processing, the motor at a cycle of 360 degrees at the start of operation of the vehicle The rotor angle can be detected and the d-axis command voltage is applied, and the time until the vehicle can travel can be shortened.

  An example of an embodiment of the present invention will be described with reference to FIGS. 1 is a configuration diagram of a DC brushless motor, FIG. 2 is a control block diagram of a control device that controls the operation of the DC brushless motor shown in FIG. 1, FIG. 3 is an operation flowchart of the control device shown in FIG. FIG. 5 is a graph showing the timing of switching the current feedback gain and the timing of superimposing the magnetic pole direction discriminating current. FIG. 5 compares the responsiveness of the change in the q-axis current when the current feedback gain is changed and the magnetic pole direction discriminating current is superimposed. FIG. 6 is a graph comparing the magnitude of the q-axis current when the d-axis command voltage is applied while changing the current feedback gain.

  The DC brushless motor control device 10 (hereinafter simply referred to as the control device 10) shown in FIG. 2 is a hybrid vehicle (this book) including the DC brushless motor 1 (hereinafter simply referred to as the motor 1) and the engine 2 shown in FIG. It is mounted on a vehicle using the inventive motor as a source of driving force for the driving shaft. In the hybrid vehicle, the drive shaft of the motor 1 and the engine 2 is directly connected, and the motor 1 and the engine 2 cooperate to rotate the drive shaft (not shown). Further, the engine 2 is cranked by the motor 1 when the engine 2 is started. In addition, an ignition switch 13 is provided for switching the hybrid vehicle between a driving state and a stopped state.

  The control device 10 performs feedback control of the current flowing through the armatures 3, 4 and 5 of the motor 1 shown in FIG. It is converted into an equivalent circuit using a dq coordinate system having a shaft armature and a d-axis armature on a d-axis orthogonal to the q-axis.

  Then, the control device 10 determines a current flowing through the d-axis armature (hereinafter referred to as a d-axis current) according to the d-axis command current Id_c and the q-axis command current Iq_c applied according to the driving state of the hybrid vehicle. Feedback control is performed on a current flowing through the q-axis armature (hereinafter referred to as a q-axis current).

  In addition, the control device 10 determines the voltage applied to the d-axis armature (hereinafter referred to as d-axis voltage Vd) and the voltage applied to the q-axis armature (hereinafter referred to as q-axis voltage Vq) as U, A dq / 3-phase converter 20 that converts drive voltages Vu_c, Vv_c, and Vw_c to be applied to three-phase armatures V and W, and high-frequency voltages vu, vv, A high frequency superimposing unit 21 for superimposing vw, and a plurality of switching elements so as to apply voltages Vu, Vv, Vw corresponding to the drive voltages Vu_c, Vv_c, Vw_c to the armatures of the U, V, W phases of the motor 1 Are provided with a power drive unit 22 composed of an inverter circuit bridge-connected.

  Further, the control device 10 detects a current flowing through the U-phase armature of the motor 1 (corresponding to the current detection means of the present invention), and a current flowing through the W-phase armature of the motor 1. According to the detected W-phase current sensor 24 (corresponding to the current detecting means of the present invention), the detected current value Iu_s of the U-phase current sensor 23, the detected current value Iw_s of the W-phase current sensor 24, and the rotor angle θ of the motor 1. Thus, a three-phase / dq converter 26 for calculating a d-axis actual current Id_s that is a detected value of the d-axis current and a q-axis actual current Iq_s that is a detected value of the q-axis current (corresponding to the actual current calculating means of the present invention). A rotor angle detector 25 (corresponding to the rotor angle detector of the present invention) that detects the rotor angle θ of the motor 1, and a process for canceling the influence of the speed electromotive force that interferes between the d axis and the q axis. A non-interference calculating unit 27 is provided.

  Then, the control device 10 subtracts the d-axis command current Id_c and the d-axis actual current Id_s by the first subtractor 28 according to the following formula (1), and PI (29) Proportional integration) processing is performed, the non-interference component is added by the first adder 30, and the d-axis command voltage Vd_c corresponding to the deviation (Id_c-Id_s) between the d-axis command current Id_c and the d-axis actual current Id_c is determined. . In this case, if the non-interference component is ignored, Vd_c is expressed by the following equation (1).

  However, Kp: proportional gain, Ki: integral gain, S: integral symbol.

  Similarly, the control device 10 subtracts the q-axis command current Iq_c and the q-axis actual current Iq_s by the second subtractor 31, performs a PI process on the subtraction result by the second PI operation unit 32, A non-interference component is added by the two adder 33 to determine a q-axis command voltage Vq_c corresponding to a deviation (Iq_c−Iq_s) between the q-axis command current Iq_c and the q-axis actual current Iq_s. In this case, if the non-interference component is ignored, the q-axis command voltage Vq_c is expressed by the following equation (2).

  Then, the control device 10 inputs the d-axis command voltage Vd_c and the q-axis command voltage Vq_c to the dq / 3-phase conversion unit 20. Thus, the three-phase voltages VU, VV, VW that reduce the deviation between the d-axis command current Id_c and the d-axis actual current Id_s and the deviation between the q-axis command current Iq_c and the q-axis actual current via the power drive unit 22. Is applied to the armature of the motor 1, and the current flowing through the armature of the motor 1 is feedback controlled.

  The first subtractor 28, the first PI operation unit 29, the first adder 30, the second subtractor 31, the second PI operation unit 32, and the second adder 33 determine the command voltage of the present invention. Means are configured. Further, the dq / 3-phase converter 20 and the power drive unit 22 constitute the energizing means of the present invention.

  Here, when the dq / 3-phase converter 20 converts the d-axis command voltage Vd_c and the q-axis command voltage Vq_c into three-phase command voltages VU_c, VV_c, VW_c, the rotor angle θ of the motor 1 (see FIG. 1). )Is required. Also, when the detected current value Iu_s of the U-phase current sensor 23 and the detected current value Iw_s of the W-phase current sensor 24 are converted into the d-axis actual current Id_s and the q-axis actual current Iq_s by the three-phase / dq conversion unit 26, The rotor angle θ of the motor 1 is required.

  And the angle detection part 25 detects rotor angle (theta), without using position detection sensors, such as a resolver. The angle detector 25 receives the high-frequency voltages vu, vv, vw_c, and the three-phase command voltages VU_c, VV_c, and VW_c via the third adder 34, the fourth adder 35, and the fifth adder 36 by the high-frequency voltage superimposing unit 21. The sine reference value Vs is calculated by the following equation (3) according to the detected current value Iw_s of the U-phase current sensor 23 and the detected current value Iw_s of the W-phase current sensor 24 when vw is superimposed. The cosine reference value Vc is calculated from (4).

  However, K: calculation gain, Δl: variation of U, V, W phase self-inductance l.

  However, K: calculation gain, Δl: variation of U, V, W phase self-inductance l.

  And the angle detection part 25 calculates rotor angle (theta) by the following formula | equation (5).

  Here, the rotor angle calculated by the above formulas (4) to (5) has a cycle of 180 degrees, and in order to detect the rotor angle at a cycle of 360 degrees, it is necessary to determine the direction of the magnetic poles of the rotor. . Therefore, the angle detection unit 25 calculates the following equation based on the sine reference value Vs according to the above equation (3) and the cosine reference value Vc according to the above equation (4) when the magnetic pole direction discrimination current is superimposed on the q-axis command current Iq_c. The magnetic pole discrimination value A is calculated by (6) to discriminate the direction of the magnetic pole of the rotor.

  Here, when a magnetic field is generated in the q-axis direction (the magnetic flux direction of the magnet of the rotor 2) by superimposing the magnetic pole determination current on the q-axis current command Iq_c, the direction of the magnetic field generated by the magnetic pole determination current and the rotor 2 When the magnetic field generated by the magnet is in the same saturation state, the fluctuation amount Δl of the self-inductance increases. On the other hand, when the magnetic field generated by the magnetic pole discrimination current and the magnetic field generated by the magnet of the rotor 2 are in the non-saturated state, Δl is small.

  Therefore, the magnetic pole discriminating value A value calculated by the above formula (6) from the sine reference value Vs and the cosine reference value Vc that change depending on the value of Δl changes. Therefore, the direction of the magnetic pole of the rotor 2 can be determined by changing the direction (positive / negative) of the magnetic pole determination current and determining the saturated state and the non-saturated state.

  Next, according to the flowchart shown in FIG. 3, the operation of the control device 10 when the ignition switch 13 (see FIG. 2) of the hybrid vehicle is turned on will be described. When the ignition switch 13 is turned ON in STEP1, the process proceeds to STEP2, and in STEP2, the proportional gain Kp and the integral gain Ki in the first PI calculation unit 29 and the second PI calculation unit 32 (the above formulas (1) and (2) ), Which corresponds to the feedback gain of the present invention, is set to “large”. Here, the proportional gain Kp and the integral gain Ki are set by the following equations (7) and (8), and the magnitudes of the proportional gain Kp and the integral gain Ki are changed by changing the value of the variable τ. .

  Where L is a constant corresponding to the inductance of the armature of the motor 1, and τ is a variable for gain setting.

  Where R is a constant corresponding to the resistance of the armature of the motor 1, and τ is a variable for gain setting.

  The proportional gain Kp and the integral gain Ki set to “large” correspond to the first gain of the present invention.

  Then, the rotor angle detection unit 25 starts “rotor angle detection processing” in which the high-frequency voltage is superimposed as described above to detect the rotor angle at a cycle of 180 degrees as described above, and the magnetic pole is detected as described above at STEP 4. A “rotor magnetic pole direction determining process” for determining the direction of the magnetic pole of the rotor 2 by superimposing the direction determining current is started.

In the next STEP 5 , when the “rotor magnetic pole direction determination process” is completed and the rotor angle θ in a period of 360 degrees is determined, the process proceeds to STEP 6, where the first PI calculation portion 29 and the second PI calculation unit 32 The proportional gain Kp and the integral gain Ki are switched to “small” which is smaller than the “large” setting in STEP2.

  Then, in subsequent STEP 7, application of the d-axis command current Id_c, which is a torque command current, is started, whereby the control device 10 uses the proportional gain Kp and the integral gain Ki set to “small” and the d-axis command voltage Vd_c. Is calculated.

FIG. 4A is a graph showing the switching timing of the proportional gain Kp and the integral gain Ki and the switching timing of the rotor angle detection process. The vertical axis is set to the rotational speed N of the motor 1, and the horizontal axis Is set at time t. And a in the figure has shown transition of the rotation speed N of the motor 1. FIG. In the figure, t _{10 to} t ₁₅ correspond to the processing from STEP 2 to STEP 5 in the flowchart of FIG. 3, and the proportional gain Kp and the integral gain Ki are set to “large”.

Further, t ₁₅ corresponds to the process of STEP6~STEP7 in the flowchart of FIG. 3, the proportional gain Kp and the integral gain Ki in t ₁₅ the application of d-axis command current Id_c is started is set to "small" . As a result, the motor 1 starts rotating speed N increases, at t ₁₆ the rotational speed N reaches N1, from the accompanying superposition of high frequency voltage corresponding to the low-speed region "rotor angle detection process" Then, switching to the rotor angle detection process for the high rotation region in which the rotor angle is detected by the counter electromotive voltage generated in the armature of the motor 1 without superimposing the high frequency voltage.

FIG. 4B shows in detail the execution timing of the “rotor angle detection process” and the “rotor magnetic pole direction determination process” from t ₁₀ to t ₁₅ in FIG. 4A. The “rotor angle detection process” is started at t ₁₀ in the figure. Further, in t ₁₁ ~t ₁₂ positive pole determination current is superimposed on the q-axis command current Iq_c, negative pole determination current in t ₁₃ ~t ₁₄ is superimposed on the q-axis command current Iq_c.

  In this manner, the positive / negative magnetic pole discrimination current is superimposed on the q-axis command current Iq_c, and the three-phase / dq conversion unit 26 and the dq / are determined by the rotor angle having a cycle of 180 degrees detected by the “rotor angle detection process”. Conversion processing by the three-phase conversion unit 20 is performed to apply drive voltages VU, VV, VW to the armature of the motor 1, and the magnetic pole discrimination value A is calculated by the above equation (6). Then, the rotor angle detection unit 25 determines the direction of the magnetic pole of the rotor 2 from the detection result of the saturation state / non-saturation state based on the direction (positive / negative) of the magnetic pole determination current and the magnetic pole determination value A.

Next, in FIGS. 5 and 6, as described above, the magnitudes of the proportional gain Kp and the integral gain Ki are set to “large” when the “rotor magnetic pole discrimination process” is executed, and the application of the d-axis command current Id_c is started. The rest is a graph showing the effect of switching to “small”.

First, FIGS. 5A and 5B are graphs in which the vertical axis is set to the q-axis current Iq and the horizontal axis is set to the time t, and d in FIG. 5A is the proportional gain Kp. The change of the q-axis current Iq is shown when the integral gain Ki is set to “large” and the superposition of the magnetic pole direction discrimination current is started at t ₂₀ . In this case, the time required from the start of the superposition of the magnetic pole facing discrimination current to the q-axis current Iq to peak value I ₂₀ is the t ₂₀ ~t _21.

On the other hand, e in FIG. 5B shows a change in the q-axis current Iq when the proportional gain Kp and the integral gain Ki are set to “small” and the superposition of the magnetic pole direction discrimination current is started at t _30. ing. In this case, the time required for the q-axis current Iq to reach the peak value I ₂₀ after the superposition of the magnetic pole direction determination current is t ₃₀ to t ₃₁ , and t ₂₀ to t shown in FIG. Longer than ₂₁ .

  Therefore, by setting the proportional gain Kp and integral gain Ki to “large” when executing the “rotor magnetic pole discrimination processing”, the response of the change in the q-axis current when the magnetic pole orientation discrimination current is superimposed becomes faster. Since the time for waiting for the rise of the q-axis current can be set short, the time required for the “rotor magnetic pole discrimination process” can be shortened.

  FIG. 6A and FIG. 6B are graphs in which the vertical axis is set to the rotor angle θ and the phase current, and the horizontal axis is set to time t. FIG. 6A shows the case where the proportional gain Kp and the integral gain Ki are set to “large” and the d-axis torque command current Id_c is applied. In FIG. 6, f indicates the transition of the rotor angle θ. The middle g indicates the transition of the phase current.

Here, when the d-axis command current Id_c that is the torque command current is applied, the q-axis command current Iq_c that is the field command current is normally set to 0, but the q-axis command current is set according to the rotor angle detection error Δθ. Deviation occurs between the current Iq_c and the q-axis actual current Iq_s. Then, the q-axis command voltage Vq_c corresponding to the deviation is calculated and a phase current is generated. In FIG. 6A, the magnitude (peak to peak) of the phase current is I _{10 to} I ₁₁ .

On the other hand, FIG. 6B shows a case where the proportional gain Kp and the integral gain Ki are set to “small” and the d-axis torque command current Id_c is applied. In the figure, h shows the transition of the rotor angle θ. i indicates the transition of the phase current. In FIG. 6B, the magnitude (peak to peak) of the phase current is smaller than I _{10 to} I ₁₁ in FIG.

  Here, the q-axis current Iq has a function of demagnetizing the magnet of the rotor 2. For this reason, after the “rotor magnetic pole direction discrimination processing” is completed, the proportional gain Kp and the integral gain Ki are set to “small” to reduce the q-axis current Iq as shown in FIG. Demagnetization of the magnet of the rotor 2 can be suppressed.

  In this embodiment, the settings of the proportional gain Kp and the integral gain Ki are switched between “large” and “small”. However, only the setting of the proportional gain Kp may be switched between “large” and “small”. Good.

  In the present embodiment, the DC brushless motor control device 10 of the present invention is mounted on a hybrid vehicle. However, the embodiment of the present invention is not limited to this, and the magnetic pole direction determination processing of the rotor is performed. The present invention can be widely applied to DC brushless motor control devices.

The structural diagram of a DC brushless motor. The control block diagram of the control apparatus which controls the action | operation of the DC brushless motor shown in FIG. The operation | movement flowchart of the motor control apparatus shown in FIG. The graph which showed the timing which superimposes the timing which switches a current feedback gain, and a magnetic pole direction discriminating current. The graph which compared the change of the responsiveness of the q-axis current when the current feedback gain is changed and the magnetic pole direction discrimination current is superimposed. The graph which compared the magnitude | size of the q-axis current when changing a current feedback gain and applying a d-axis command current.

  DESCRIPTION OF SYMBOLS 1 ... DC brushless motor, 2 ... Rotor, 3 ... U-phase armature, 4 ... V-phase armature, 5 ... W-phase armature, 10 ... DC brushless motor control device, 11 ... Engine, 20 ... dq / 3 phase conversion unit, 21 ... high frequency superposition unit, 22 ... power drive unit, 23 ... U phase current sensor, 24 ... W phase current sensor, 25 ... angle detection unit, 26 ... 3 phase / dq conversion unit, 27 ... non-interference Calculation unit

Claims (2)

A DC brushless motor is handled by converting it into an equivalent circuit having a q-axis armature on the q-axis that is the magnetic flux direction of the field of the motor and a d-axis armature on the d-axis orthogonal to the q-axis. ,
Current detection means for detecting a current flowing in the armature of the motor;
Actual current calculation means for calculating a q-axis actual current flowing in the q-axis armature and a d-axis actual current flowing in the d-axis armature from the current value detected by the current detection means and the rotor angle of the motor. When,
A q-axis current deviation which is a deviation between a q-axis command current which is a command value of a current flowing through the q-axis armature and a q-axis actual current, and a d-axis command current which is a command value of a current which flows through the d-axis armature And a d-axis command voltage which is a command value of a voltage applied to the d-axis armature and a voltage applied to the q-axis armature so as to reduce a d-axis current deviation which is a deviation between the d-axis actual current and the d-axis actual current. Command voltage determining means for determining a q-axis command voltage which is a command value;
An energization control means for determining a drive voltage to be applied to the armature of the motor based on the d-axis command voltage and the q-axis command voltage and performing energization control of the motor;
When the rotational speed of the motor is less than a predetermined value, the rotor angle of the motor is determined based on the current value detected by the current detection means when a high-frequency voltage for rotor angle detection is superimposed on the drive voltage. The rotor of the motor is detected based on a rotor angle detection process for a low rotation range detected at a cycle of 180 degrees and a current value detected by the current detection means when a magnetic pole direction determination current is superimposed on the q-axis command current. The rotor magnetic pole direction discrimination process for discriminating the magnetic pole direction of the motor is detected , the rotor angle of the motor is detected at a cycle of 360 degrees, and the superposition of the high-frequency voltage is performed when the rotational speed of the motor is not less than the predetermined value. without, Bei a rotor angle detection means for performing a high rpm rotor angle detection process for detecting the rotor angle of the motor by back electromotive force generated in the armature of the motor The control device of the DC brushless motor has,
The command voltage determination means determines the q-axis command voltage by multiplying the q-axis current deviation by a first gain when the rotor magnetic pole direction determination processing is executed, and the rotor magnetic pole direction determination processing ends. When the rotor angle detection processing for the low rotation range is executed after the application of the d-axis command current is started , the second gain smaller than the first gain is added to the q-axis current deviation. To determine the q-axis command voltage. DC brushless motor control device. It is mounted on a vehicle that uses the motor as a source of driving force for the drive shaft,
At the start of operation of the vehicle, after the rotor angle estimation process and the rotor magnetic pole direction detection process are executed by the rotor angle detection means, the rotor angle of the motor can be detected at a cycle of 360 degrees. 2. The control apparatus for a DC brushless motor according to claim 1, wherein application of the d-axis command current for controlling the torque current of the motor is started.

Images