KR101686352B1 - Method For Designing The Controller Of Lead Angle - Google Patents

Method For Designing The Controller Of Lead Angle Download PDF

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Publication number
KR101686352B1
KR101686352B1 KR1020150159503A KR20150159503A KR101686352B1 KR 101686352 B1 KR101686352 B1 KR 101686352B1 KR 1020150159503 A KR1020150159503 A KR 1020150159503A KR 20150159503 A KR20150159503 A KR 20150159503A KR 101686352 B1 KR101686352 B1 KR 101686352B1
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South Korea
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phase
phase angle
stator
angle
stators
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KR1020150159503A
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Korean (ko)
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공경철
이명석
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서강대학교산학협력단
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/28—Arrangements for controlling current
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/08—Arrangements for controlling the speed or torque of a single motor
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/34—Modelling or simulation for control purposes

Abstract

The present invention relates to a method for designing a phase angle controller capable of improving the efficiency and torque performance of a BLDC motor in a high speed region.

Description

{Method For Designing The Controller Of Lead Angle}

The present invention relates to a phase angle controller design method. More particularly, the present invention relates to a method for designing a phase angle controller capable of improving the efficiency and torque performance of a BLDC motor in a high speed region.

Brushless Direct Current (BLDC) motor is a motor that eliminates commutators and brushes that have mechanical contact structure in a conventional direct current motor and substitutes it with an electronic rectifier. The electromagnetic noise and mechanical noise And has a long life span.

At present, brushless DC motors have made remarkable progress due to high performance of devices, light and short life, longevity, and advancement of parts and materials centering on semiconductor technology, so that they can be used in home appliances, It is widely used in various fields.

Such a brushless DC motor generally has a rotor as a permanent magnet and a stator as a fixed account winding, in particular a three-phase stator, detects the position of the rotor by a position sensor such as a hall sensor, The brushless direct current (DC) motor is driven so that voltage application and release are repeated for each stator according to the position of the electron.

Here, when the rotor rotates and the brush-less DC motor is driven, an effect similar to the movement of the conductor is generated, and a back electromotive force, which is an electromotive force, is generated in each stator. Therefore, The winding current flows according to the voltage.

Therefore, in an ideal driving mode of the brushless DC motor, the signal of the hall sensor is detected and the voltage of the stator is applied and released, that is, the phase of the stator is switched. However, due to the influence of the winding inductance of the motor, In particular, when the inductance is large and the motor rotates at a high speed, the delay angle of the phase current increases, which may lead to problems such as reduction of the efficiency of the brushless DC motor and reduction of the torque performance.

In order to solve such a problem, in driving the brushless DC motor, the phase current switching must be performed at a higher angle than the phase change point by a certain angle (alpha), and the preceding angle alpha is referred to as a lead angle And the magnitude of alpha can be determined by the resistance and inductance of the motor, the rotation speed of the motor, and the like.

Conventionally, a method for controlling the phase angle is a method of controlling the phase angle of an output signal in accordance with the rotation speed of the electric motor by detecting the phase difference between the input signal and the output signal and controlling the voltage- However, in the case where disturbance acts on the motor, the phase angle at which the efficiency of the speed change is optimized can not be obtained. Alternatively, the phase angle can be obtained by using a phase locked loop (PLL) The method of implementing the phase angle control by removing the harmonics by implementing the differentiator through the circuit improves the efficiency performance of the motor at high speed, but has a problem that the efficiency of the motor is lowered at low speed.

Further, although there is a method of controlling the information about the phase angle by the phase angle prediction through the curve fitting, the curve fitting equation should be applied differently according to the characteristics of the motor and the characteristics of the system. Therefore, There was a problem.

Therefore, it is possible to guarantee the efficiency of the motor at high speed as well as at low speed without being affected by the disturbance which may be applied to the motor, and it is possible to improve the efficiency and torque performance of the motor through the step- It is urgently required to provide a technique for controlling the phase angle of the DC motor.

The present invention can eliminate the influence of the external environment on the phase angle control and can analyze the driving state in real time to derive the phase angle and control the phase angle through the phase angle estimation of the simplified procedure, And to provide a method of designing a phase angle controller capable of improving the efficiency and torque performance of the phase angle controller.

According to an aspect of the present invention, there is provided a phase angle controller designing method including a phase angle calculation unit, an encoder, and a phase current switching unit, the phase angle switching unit including a BLDC motor A target function derivation step of deriving an objective function that can be calculated according to a rotational speed of the BLDC electric motor based on the phase angle calculated by the phase angle calculation unit; Wherein the encoder counts the number of phase change pulses counted during the switching step and derives the number of phase advance angles, which is the number of pulses corresponding to the phase angle calculated through the objective function, A forward angle control time determination step of determining the control time point of the leading angle in the phase change step through the number of pulses, Calculating a phase angle from the target function derived from the phase derivation step, determining a control time point of the phase angle from the phase angle control time determination step, And a phase advance angle controller designing step of designating a phase advance angle controller to switch a phase current of the stator so as to compensate a delay in phase current switching for phase change of a plurality of the stator.

Here, the objective function deriving step may include: deriving a phase-voltage waveform of the BLDC motor using a Fourier series

Figure 112015110703563-pat00001
The above objective function can be derived from the above equation.

* ω e is the electrical angular velocity of the BLDC motor, b n is the coefficient of v (t)

Figure 112015110703563-pat00002
, v (t) is the sum of sine waves as a periodic function, and t is time.

In this case, the objective function deriving step derives the objective function represented by the phase angle of the first equation with respect to the magnitude and weight of the phase current delay for each term of v (t)

Figure 112015110703563-pat00003
- Formula 1

Figure 112015110703563-pat00004
- The second equation

The objective function may be curve fitted to simplify to the second equation.

ω e is the electrical angular velocity of the BLDC motor, L is the phase angle of the rotor due to the winding itself of the stator, c n / N is the weight, tan -1 (nLω e / R) is the phase delay of phase- inductance, R is resistance, and k1 and k2 are constants for determining a curve fitting, dθ is the fast each, dθ is a truth each showing a simplified dθ of the stator.

In the phase angle controller designing step, when the number of phase-change pulses counted by the encoder reaches the number of phases of phase-correcting angles, the phases of the plurality of stators The phase angle controller can be designed to switch the phase current so as to correct the driving of the BLDC electric motor with respect to the phase current delay.

The phase angle controller designing step may design the phase angle controller to switch the phase currents of the plurality of stators by controlling the application of current to the stator to be excited by the phase change through the phase current switching unit.

Here, the phase advance angle controller design step may include switching the phase currents of the plurality of stators through the phase current switching unit by a delay of phase current switching to the phase change point of time of the plurality of stators, The phase advance angle controller can be designed to switch the phase currents of the plurality of stator at the same time as the switching.

In this case, the phase angle control time determination step may include detecting a phase change completion of the plurality of stators through an electrical signal for sensing a magnetic pole of the rotor, the sensor signal being sensed by a hall sensor for sensing the magnetic pole of the rotor, The control point of time of the phase angle in the phase change step is determined through the encoder which counts the number of phase change pulses during the phase change step and derives the number of phase advance pulse on the basis of the phase change completion point of the stator .

In the phase angle controller designing step, the stator, to which a current is to be applied based on the electrical signal provided from the Hall sensor, is controlled to apply a current to the stator according to a predetermined truth table through the phase current switching unit, The phase advance angle controller can be designed to switch the phase current of the stator.

The phase angle control time determination step may include detecting the phase change completion of the encoder or the plurality of stators capable of counting the phase change pulse number by rotating with the rotor and detecting the rotation state of the rotor The rotation speed of the BLDC motor can be detected from the Hall sensor, and the control point of time of the leading angle according to the rotation speed of the BLDC motor can be determined through the encoder.

Here, when the phases of the plurality of stator are completely switched, the phase angle control time determination step determines, via the encoder, the phase angle corresponding to the phase angle corresponding to the rotational speed of the BLDC motor, The number of pulses can be derived again and the control point of the phase angle can be synchronized with the rotation speed of the BLDC motor after completion of the phase change.

When the phases of the plurality of stators are completed, the phase angle control time determining step counts the number of phase-change pulses in the initialized state through the encoder, It is possible to provide a reference of the control point of the phase angle.

According to one embodiment of the present invention, a phase angle controller capable of performing phase angle control at a more accurate phase angle control point by using an encoder capable of detecting the phase change step of the BLDC motor more precisely .

Also, it is possible to design the phase angle controller which can calculate the phase angle according to the rotation speed of the BLDC motor at a higher speed by deriving the phase angle using the simplified objective function.

Further, at the phase change step of the stator, the control phase of the phase angle is derived from the initialized information, and the influence of the external environment, which may affect the phase angle control point of the BLDC motor, is excluded. The controller can be designed to be able to do.

1 shows a driving system of a BLDC motor according to an embodiment of the present invention.
FIG. 2 illustrates the rotation of the rotor according to the phase change and phase change of the two-phase excitation type BLDC motor according to the embodiment of the present invention.
3 is a flowchart of a phase angle controller designing method according to an embodiment of the present invention.
4 shows the phase voltage waveform of the BLDC motor.
5 shows the phase voltage waveform of a BLDC motor developed with a Fourier series.
6 is a graph showing a delay angle of a BLDC motor according to an exemplary embodiment of the present invention as a control group.
Figure 7 shows an encoder in accordance with an embodiment of the present invention.
FIG. 8 shows a sequence chart of a phase angle controller according to an embodiment of the present invention.
9 shows a truth table for controlling phase current switching of a stator according to an embodiment of the present invention.
FIG. 10 shows a phase angle control circuit diagram for implementing phase angle control of a BLDC motor according to a truth table according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Like reference numerals designate like elements throughout the specification.

The present invention relates to a method of designing a phase angle controller for controlling a phase angle of a brushless direct current (BLDC) electric motor for rotating a rotor in accordance with a phase change step of a plurality of stators, Before explaining the method of designing the controller, the configuration and driving mode of the BLDC motor can be schematically illustrated for a better understanding of the present specification.

Hereinafter, the BLDC motor will be described as a three-phase BLDC motor having three stators based on one rotor for convenience of description.

However, it should be understood that the BLDC electric motor is applicable to the BLDC electric motor having more phases (for example, four phases).

FIG. 1 shows a driving system of a BLDC motor according to an embodiment of the present invention. FIG. 2 is a view illustrating a rotation of a rotor according to an embodiment of the present invention, Lt; / RTI >

The BLDC motor 10 may include a stator 11 and a rotor 12. The stators 11 of the three phases U, V and W may be arranged at intervals of 120 degrees, (N pole or S pole) depending on the direction of the current flowing in the stator 11.

The BLDC electric motor 10 according to the embodiment of the present invention may be constructed so that only two of the stator 11 of the three phase (U, V, W) are excited and the other phase is excited, The rotor 12 can be rotated.

2, a BLDC motor 10 according to an embodiment of the present invention selectively generates a potential difference between the stator 11 of two phases among the stator 11 of three phases (U, V, W) The rotor 12 can be rotated.

2, in the phase-change step 1 (a), a current is applied from the U-phase stator 11 to the W-phase stator 11, and because of the characteristics of the current flowing from the high potential to the low potential, U The stator 11 on the stator 11 and the stator 11 on the W phase can have a negative potential.

As a result, the stator 11 of the U phase attracts the S pole of the rotor 12, and the stator 11 of the W phase pushes the S pole of the rotor 12, 12 can rotate so that the S pole moves in the direction of the stator 11 from the stator 11 on the W phase.

2, the stator 11 of the V phase is connected to the stator 11 of the positive potential and the stator 11 of the W phase by applying a current from the stator 11 of the V phase to the stator 11 of the W phase, (11) can deviate from the potential.

Therefore, the stator 11 of the W phase attracts the N pole of the rotor 12, and the stator 11 of the V phase pushes the N pole of the rotor 12, Can be rotated so that the N pole moves in the direction of the stator 11 from the stator 11 of the V phase.

The rotor 12 can be rotated in the above-described manner also in the phase change steps 3 to 6 ((c) to (f) of FIG. 2) 1 to 6 ((a) to (f)).

As described above, the BLDC motor 10 controls the phase change of the stator 11 of three phases (U, V, W), that is, the stator 11 of three phases (U, V, W) By applying a current through the stator 11 on the stator 11 to excite the stator 11 and controlling the potential difference between the stator 11 of the two phases to be excited, So that the rotor 12 can be rotated.

The BLDC motor 10 is provided with the stator 11 of three phases (U, V, W) so that the stator 11 of three phases (U, V, W) The phase change step of the stator 11 may be changed in accordance with the number of the stator 11. The phase change step of the stator 11 may be changed according to the number of phases U +, U-, V +, V-, W +, W- . For example, when the stator 11 is provided in six phases, it is possible that the phase change of the stator 11 is composed of 12 steps.

The BLDC motor 10 may be driven by rotating the rotor 12 through a phase change of a plurality of the stators 11. The BLDC motor 10 may be driven by the rotor 12 The two stators 11 of the three phases (U, V, W) of the stator 11 must be energized in accordance with the rotation state of the rotor 12 so that the information on the rotation state of the rotor 12 must be clear There is a need.

More specifically, referring to FIG. 2, the rotor 12 (12) is connected between the stator 11 of the U phase of the U phase excited to the positive potential through the phase change step 1 When the stator 11 is switched to the phase switching step 2 (b) in a state in which the S pole of the rotor 12 is not accurately located, the rotor 12 may be configured to implement an irregular rotation form, It may be rotated.

Therefore, the BLDC motor 10 accurately grasps the rotation mode of the rotor 12, and after the rotation of the rotor 12 is completed, the plurality of stator 11 is switched to the next step The rotation of the rotor 12 can be continued.

Here, the BLDC motor 10 may include a position sensor for detecting the rotation state of the rotor 12 and realizing accurate rotation of the rotor 12 through the position sensor, (HA) capable of detecting magnetic poles of S-pole or N-pole formed on the rotor 12, for example, as long as it can detect the rotation state of the rotor 12, , HB, HC) can be mainly used.

The hall sensors HA, HB and HC may convert a signal of a magnetic pole sensed by the rotor 12 into an electric signal and transmit the electric signal to the inverter 20 which applies a current to the stator 11.

The hall sensors HA, HB, and HC may be designed to sense N poles or S poles among the poles of the rotor 12, The hall sensors HA, HB, and HC are designed to sense the N pole of the rotor 12 in order to simplify the explanation. In the present specification, for example, Can be explained.

Referring to FIG. 2, the Hall sensors HA, HB and HC may be provided between the stators 11 of three phases (U, V, W).

The present invention is characterized in that the Hall sensors HA, HB and HC are provided between the stator 11 of three phases (U, V, W) and the stator 11 of three phases (U, V, W) And the BLDC motor 10 may be provided as an example.

The rotor 12 is rotatable through a phase change of the stator 11 of three phases (U, V, W). In this case, a position opposite to the N pole of the rotating rotor 12 The hall sensors HA, HB, and HC can sense the N pole of the rotor 12.

2, in the phase change step 1 (a), the N pole of the rotor 12 faces the hall sensors HB and HC located on both sides of the stator 11 on the V phase, The Hall sensors HB and HC can sense the N pole of the rotor 12 and in the phase change step 2 (b), the N pole of the rotor 12 is connected to the stator 11 and / The Hall sensor HC can sense the N pole of the rotor 12 because the Hall sensor HC opposes the Hall sensor HC located between the stator 11 of the W phase.

The Hall sensors HA, HB and HC sense the N pole of the rotor 12 and sense the N of the rotor 12 from the Hall sensors HA, HB and HC, The inverter 20 can be switched to an electric signal and transmitted to the inverter 20. The inverter 20 can switch the phase of the plurality of the stator 11 according to the electrical signal, can do.

Therefore, the plurality of stator 11 are switched in phase current through the current applied from the inverter 20, so that the rotor 12 can rotate.

It can be understood that the detection of the N pole of the rotor 12 through the hall sensors HA, HB and HC detects the completion of the phase change of the plurality of stators 11.

That is, the rotor 12 rotates through a phase change of each phase of the stator 11 of three phases (U, V, W), and the N pole of the rotor 12, which rotates, It can be understood that the rotation of the rotor 12 in the phase change step is completed when the sensors HA, HB, and HC detect the phases, and then the phase change step is switched to the other phase change step The rotation of the rotor 12 can be continued by switching the phases of the plurality of stators 11 so that the N pole detection of the rotor 12 through the hall sensors HA, It is reasonable to understand that the phase change of the stator 11 of Fig.

Also, the hall sensors HA, HB, and HC can detect the rotational speed of the BLDC electric motor 10.

More specifically, the Hall sensors HA, HB and HC rotate the rotor 12 in accordance with the phase changing steps (a) to (f) of the stator 11 shown in FIG. 2 The Hall sensors HA, HB and HC may determine the rotation of the rotor 12 and the time required for the rotation of the rotor 12 so that the rotation speed of the rotor 12, that is, the rotation speed of the BLDC motor 10 The rotational speed can be easily detected.

The detection of the rotational speed of the rotor 12 through the hall sensors HA, HB, and HC is a general matter in the prior art, and thus the detailed description thereof can be omitted.

In order to continuously rotate the rotor 12, that is, to drive the BLDC electric motor 10 continuously, the inverter 20 drives the plurality of electric motors 10 through the electric signals provided from the hall sensors HA, HB, It is necessary to perform continuous phase current switching of the stator 11. To this end, the inverter 20 receives the electric signal, that is, the phase changeover completion signal of the stator 11, from the Hall sensors HA, And the rotor 12 is rotated by applying a current to the stator 11 to be excited to be excited while receiving the rotation of the stator 11, which is the ideal driving mode of the BLDC motor 10.

However, when a current is applied to the stator 11 to be excited to be excited by the inverter 20, the stator 11 to which the current is applied has an action of interfering with the change of the magnetic flux passing around the stator 11, , The inductance is generated, and the current application of the stator 11 to be excited, that is, the phase current switching is delayed.

Since the inductance increases as the frequency of the current increases, the delay of the phase current further increases as compared with the phase change point of the stator 11, and the delay of the phase current decreases the efficiency of the BLDC motor 10 And reduction in torque performance.

Therefore, in order to prevent the degradation of the performance of the BLDC motor 10 due to the delay of the phase current switching for the phase change of the stator 11, a lead angle control technique is introduced in the BLDC driving .

When the BLDC motor 10 is driven, the phase angle of the stator 11 is controlled through the phase angle control, , It is possible to sufficiently compensate the delay of the phase current with respect to the phase change between the stator (11).

In order to compensate the delay of the phase current switching for the phase change of the stator 11, the phase angle control method may be implemented by the phase angle controller 100 applied to the BLDC motor, A method for designing the phase angle controller 100 applied to the controller 10 will be described.

3 is a flowchart of a phase angle controller designing method according to an embodiment of the present invention.

The phase angle controller design method according to an embodiment of the present invention includes a phase angle calculation unit 110, an encoder 120 and a phase current switching unit 130. In accordance with the phase change step of the plurality of stators 11, The present invention relates to a method of designing a phase angle controller for controlling the phase angle of a BLDC motor 10 for rotating an electron 12. The phase angle calculator 110 calculates a phase angle of the rotor 12 based on the rotation angle of the BLDC motor 10 A target function derivation step (S100) of deriving an objective function that can be calculated according to a speed, a step of counting the number of phase change pulses counted during the phase change step, Phase angle control time determination step (step (b)) for determining the control time point of the leading angle in the phase change step through the phase change pulse number and the phase angle pulse number S2 00) and the objective function derived from the objective function deriving step (S100), determines the control point of the phase angle from the phase angle control time determination step (S200) The phases of the plurality of stators 11 are switched through the phase current switching unit 130 at the control point of each phase to compensate for the delay of phase current switching for phase switching of the plurality of stators 11, And a phase angle controller designing step S300 for designing a phase angle controller 100.

The phase angle calculation unit 110 can calculate the phase angle to compensate for the delay of the phase current change for the phase change of the stator 11.

Here, it is very important to design an algorithm for calculating the phase angle by the phase angle calculation unit 110. The algorithm for calculating the phase angle is based on the driving environment of the BLDC motor 10 to which the phase angle controller 100 is applied The phase angle computed by the phase angle computation unit 110 may provide a complement to the phase current delay of the BLDC motor 10 if the phase angle is not accurately derived according to the rotation speed of the BLDC motor 10 The efficiency of the BLDC electric motor 10 may be lowered.

Accordingly, the objective function deriving step S100 can derive the objective function that can be calculated according to the rotation speed of the BLDC electric motor 10 by the phase angle computed by the phase angle computing unit 110, The phase advance angle arithmetic unit 110 can derive the phase angle that can sufficiently compensate the drive of the BLDC motor 10 for phase current switching.

4 shows the phase voltage waveform of the BLDC electric motor 10. In Fig.

The voltage applied to the BLDC motor 10 is a square wave and can be represented graphically on the graph as shown in FIG.

4, there is a limit in analyzing the voltage applied to the BLDC motor 10 in the time domain, so that the phase current of the phase change of the stator 11 A problem may arise in deriving the phase advance angle in accordance with the phase change period of the stator 11 with a delay.

Accordingly, the objective function deriving step S100 may derive the objective function from the following Equation 1, which is a square wave form voltage applied to the BLDC motor 10, developed by a Fourier series.

Figure 112015110703563-pat00005

Here, ω e is the electrical angular speed, b n of the BLDC motor 10 as a function of v (t)

Figure 112015110703563-pat00006
, V (t) is the sum of sine waves as a periodic function, and t can be time.

5 shows the phase voltage waveform of the BLDC electric motor 10 developed in the Fourier series.

The phase voltage waveform of the BLDC motor 10 developed in the Fourier series through Equation (1) can be expressed as a sum v (t) of a plurality of harmonics as shown in FIG.

Here, the objective function deriving step S100 may derive the objective function represented by the phase angle of Equation (2) with respect to the magnitude and weight of the delay angle for each term of Equation (1).

Figure 112015110703563-pat00007

Here, c n / N are weight, tan -1 (nLω e / R ) is the electrical angular velocity, L the delay of the phase current of the switch, ω e is BLDC motor 10 for the switching timing between the plurality of stator 11 Is the self-inductance due to the winding of the stator 11, and d [theta] is the phase angle.

The phase voltage waveform of the BLDC motor 10 developed in the Fourier series of FIG. 5 can be expressed as a sum of a plurality of harmonics. The harmonics having a low order, such as a first order or a third order, The harmonic having a high order may have a small influence on the compensation for the delay of the phase current with respect to the phase change of the stator 11, although the compensation for the delay of the phase current with respect to the phase change of the stator 11 has a great influence.

Therefore, the weight expressed by c n / N can be applied as a coefficient capable of further highlighting the harmonics of the low order which may greatly affect the delay compensation for the phase current delay of the stator 11.

6 is a graph showing a delay angle of a BLDC motor 10 according to an exemplary embodiment of the present invention as a control group.

Referring to FIG. 6, the phase current delay of the BLDC motor 10 is smaller than that derived from the square wave form after the phase voltage of the BLDC motor 10 is expressed in the form of a sine wave through Equation (2) Can be confirmed.

6, in order to derive the phase angle according to the driving of the BLDC electric motor 10, the phase voltage of the BLDC electric motor 10 is developed by Fourier transform and the phase angle is derived therefrom The validity can be obtained.

Since the operation of Equation (2) is complicated, it may be unsuitable for calculating the true phase angle derived in real time to perform the true phase angle control in real time.

Accordingly, the objective function deriving step S100 can be expressed by the following Equation (3) by curve fitting Equation (2).

Figure 112015110703563-pat00008

Here, ω e is an electric angular velocity of the BLDC motor 10, L is a self inductance due to the winding of the stator 11, k 1 and k 2 are constants for determining curve fitting, and dθ a is a truth value Respectively.

As shown in FIG. 6, the curve fitting is represented by a graphical representation of Equation (2) on the graph, a plurality of coordinates on the generated line are set on the graph, and a new function is derived for the coordinates, Since the phase angle derived through the curve fitting and expressed by Equation (3), i.e., the objective function, is provided simpler than Equation (2), it is suitable to the present invention presented for controlling the phase angle in real time You can buy.

The objective function derived from the objective function deriving step S100 may provide information on the phase angle as shown in Equation 3. Accordingly, the phase angle controller 100 Can complement the driving of the BLDC motor 10 due to the phase current delay through the phase angle derived through the objective function.

Next, in the phase angle control time determination step S200, the number of phase change pulses counted during the phase change step is counted, and the number of pulses corresponding to the phase angle calculated through the objective function The encoder 120 that derives the number of phase-advance pulses can determine the control point of time of the phase-advance angle during the phase-change step through the number of phase-change pulses and the number of phase-advance angles.

In order to apply the phase angle that can be calculated through the objective function to the BLDC electric motor 10, the driving mode of the BLDC electric motor 10, that is, the phase of the stator 11, (12).

That is, in order for the phase angle calculated theoretically through the objective function to be applied to the BLDC electric motor 10, a reference of a time point at which the phase angle is applied during driving of the BLDC electric motor 10 should be provided.

Therefore, the step S200 of determining the phase angle control time may be performed by the encoder 120 through the encoder 120 to provide a reference of the control phase of the phase angle calculated through the objective function in each of the phase change steps The number of phase change pulses during the phase change step is counted and the number of phase advance angles calculated through the objective function is derived to determine the control phase of the phase advance angle in one phase change step.

Figure 7 illustrates an encoder 120 in accordance with one embodiment of the present invention.

The encoder 120 according to the embodiment of the present invention is configured such that the light beam projected from the light emitting element 124 passes through the slit 122 of the rotating disk 121 and then passes through the fixed slit plate 121, And passes through each of the fixed slits 126 of the light receiving element 125 and is detected by the light receiving element 127.

That is, the light emitted from the light emitting device 124 passes through the slit 122 of the rotating disk 121 and the fixed slit 126 of the fixed slit plate 125, And the pulse is repeatedly detected by the light receiving element 127 in a predetermined periodic pattern, so that the pulse can be generated.

The phase angle control time determination step S200 may include switching the phases of the encoder 120 or a plurality of the stators 11 capable of counting the number of phase change pulses rotated together with the rotor 12 Detects the rotational speed of the BLDC electric motor 10 from the hall sensors HA, HB and HC which can sense the rotational state of the rotor 12 and detects the rotational speed of the BLDC electric motor 10 through the encoder 120, It is possible to determine the control point of the leading angle according to the rotational speed of the motor 10.

The detection of the rotational speed of the BLDC electric motor 10 of the hall sensors HA, HB and HC has been described above. The encoder 120 is also capable of detecting the rotational speed of the BLDC electric motor 10 have.

Specifically, the encoder 120 is a position sensor separate from the BLDC motor 10, but rotates together with the rotor 12 of the BLDC motor 10 to generate the pulse, It is very general that the rotation speed of the BLDC motor 10 can be detected through the rotation of the rotary disk of the BLDC motor 10 or the number of pulses generated from the encoder 120. [

The rotor 12 of the BLDC motor 10 is connected to the stator 11 in accordance with the six steps of the stator 11, Phase rotation of the stator 11 is one revolution, the encoder 120 divides the generated phase angle pulse number by the number of phases of the stator 11 during the rotation of the rotating disk by one rotation, The number of pulses that can be counted through the encoder 120 during a predetermined period of time.

Also, the encoder 120 can derive the number of phases of the phase angle calculated through the objective function. For example, the phase angle of the phase change of the phase of the stator 11 through the equation (3) And the number of pulses that can be counted during one phase change step is 100 pulses, 90 pulses of 10 pulses after 100 pulses are output from the phase changeover Phase pulse number in the step.

Therefore, when the phase current of the stator 11 is switched through the control point of the phase angle determined through the phase angle control time determination step S200, the phase current of the stator 11 The control of the phase angle can be performed at the preceding point, so that the driving of the BLDC motor 10 due to the phase current delay can be sufficiently compensated.

For this purpose, the phase angle controller designing step S300 is a step of designing the phase angle controller so that, when the number of phase-change pulses counted by the encoder 120 reaches the number of phases of phase-correcting angles, The phase advance angle controller 100 may be designed to change the phase currents of the plurality of stator 11 and correct the drive of the BLDC motor 10 for the phase current delay prior to the phase change of the stator 11. [

That is, the phase angle controller 100 includes the phase angle calculation unit 110 and the encoder 120 described above, so that the rotation angle of the BLDC electric motor 10 The phase angle can be calculated according to the speed and the control phase of the phase angle can be determined through the encoder 120 according to the phase angle control time determination step S200, The phase currents of the plurality of stators 11 can be switched through the phase current switching unit 130 to compensate the drive of the BLDC motor 10 for the delay of phase current switching.

Specifically, the phase advance angle controller designing step S300 controls the application of a current to the stator 11 to be excited in accordance with the phase change through the phase current switching unit 130 so that a plurality of phase currents The phase angle controller 100 may be designed such that the phase current switching unit 130 compensates the phase current delay of the phase change of the stator 11 through the phase angle controller 100, The phase currents of the plurality of stators 11 may be switched prior to the delay of phase current switching of the plurality of stators 11 based on the phase change point of the stator 11. [

Thus, the phase angle controller 100 designed through the phase angle controller designing step S300 allows the plurality of stators 11 to be phase-switched at the same point in time as the phases of the plurality of the stators 11 are switched , It is possible to compensate the driving of the BLDC electric motor 10 with respect to the delay of the phase current switching.

FIG. 8 shows a sequence chart of phase angle controller 100 according to an embodiment of the present invention.

2 and 8, the number of phase-change pulses that can be counted in the phase-change step 1 (FIG. 2A) of the stator 11 is changed from the start point to the distance of FIG. 8B And the number of phase advancing pulses derived from the encoder 120 through the objective function is derived from the starting point to the distance of Figure 8 (a), the number of phase switching pulses counted by the encoder 120 The phase current switching unit 130 switches the phase of the W phase from the stator 11 of the V phase among the stator 11 of the three phases (U, V, and W) It is possible to control the phase current switching of the plurality of stators 11 so that current is applied in the direction of the stator 11. [

Accordingly, the inverter 20 can apply a current in the direction of the stator 11 from the stator 11 of the V-phase to the W-phase.

Here, the number of pulses of the encoder 120 between (a) and (b) in FIG. 8 may be a degree of delay in phase current switching for the phase change of the stator 11. In order to compensate the delay of the phase current, The encoder 120 can determine the time point of the phase angle control as the phase angle control point and the phase current application unit controls the phase current switching of the plurality of stators 11 at the time point a, ) Can be compensated for.

Also, the phase advance angle controller designing step S300 is a step of controlling the phases of the stator 11 to be supplied with current based on the electrical signals provided from the hall sensors HA, HB and HC through the phase current switching unit 130 The phase advance angle controller 100 may design the phase angle controller 100 to control the current application to the stator 11 according to a predetermined truth table so as to switch the phase currents of the plurality of the stator 11.

9 shows a truth table for controlling the phase current switching of the stator 11 according to an embodiment of the present invention.

The truth table is a switching function for indicating all possible combinations of 0 and 1, which are variable values indicating false and true, and values of related functions for these, as 0 and 1 as an operation table for logical operation. In one embodiment, the Hall sensor detects a variable for sensing the N pole of the rotor 12 and a variable for voltage formation according to the current application of the stator 11 of three phases (U, V, W) As a table predicting the driving mode of the BLDC on the basis of FIG.

FIG. 10 shows a phase angle control circuit for implementing phase angle control of a BLDC motor according to a truth table according to an embodiment of the present invention.

The phase angle control of the BLDC electric motor 10 through the truth table can be explained through the phase angle control circuit diagram for realizing the truth table.

9 and 10, an N-pole sense signal of the rotor 12 of the Hall sensors HA, HB, HC (FIG. 10A) , 10 (a)) may be applied to a multiplexer (FIG. 10 (b)), and the output signal of the multiplexer (FIG. 10 (U +, U-, V +, V-, W +, W-) of the stator 11 and the electric signals of the stator 11, HB, HC, To the demultiplexer (Fig. 10 (d)) that generates the demultiplexer.

The phase current switching unit 130 (FIG. 10 (c)) for switching the phase currents of the plurality of stators 11 at the control point of the leading angle angle provided in accordance with the counting of the number of pulses of the encoder 120, The phase current switching unit 130 (Fig. 10 (c)) may be connected to the demultiplexer (Fig. 10 (d)) through the demultiplexer The phase change signals of the plurality of stators can be applied to the stator.

The BLDC motor 10 according to an embodiment of the present invention includes three Hall sensors HA, HB, HC and FIG. 10 (a), and the three phases (U, V, W) 10 (d)) since the start or the non-start of the phase current switching through the phase current switching unit 130 (Fig. 10 (c)) can be selected, As shown in FIG. 9, it is possible to generate the number of twelve cases for whether or not the phase current switching unit 130 starts switching the phase current and the voltage state of the stator 11.

Therefore, the NAND logic gate (FIG. 10 (e)) for determining the phase voltage state of the plurality of stator 11 according to the truth table can be realized by the number of twelve cases of the demultiplexer (FIG. 10 (HA, HB, HC, Figure 10 (a)) and the phase current switching unit 130 (Figure 10 (c)) The phase voltage state of the stator 11 can be determined.

For example, in the phase change step 1, the electric signals of the hall sensors (HA, HB, HC, Fig. 10A) and the voltage states of the plurality of stator 11 are expressed as an equation: HC / HB / HA / U_HIGH / U_LOW / V_HIGH / V_LOW / W_HIGH / W_LOW = 1/1/0/1/0/0/0/0/1 (1 in FIG. 9).

Accordingly, the S pole of the rotor 12 can be rotated from the stator 11 to the stator 11 of the U-phase on the W phase, and the S pole of the rotor 12 can be rotated A phase change to the phase change step 2 may be generated through an electrical signal of the hall sensor HC.

In this case, the phase changeover switching unit 130 (Fig. 10 (c)) changes the phase of the stator 11 to be phase-switched and excited in the phase change step 2 before the phase change to the phase- The current application signal can be applied to the demultiplexer (Fig. 10 (d)).

10 (a)) according to the truth table according to the phase current switching start of the phase current switching unit 130 (Fig. 10 (c)). U_HIGH / U_LOW / V_HIGH / V_LOW / W_HIGH / W_LOW = 1/1/0/0/0/1/0/0 The electric signal of the stator 11 and the formulas of the voltage states of the plurality of stator / 1, the potential of the stator 11 on the V-phase is a plus pole and the potential of the stator 11 on the W-phase is a minus pole (2) in Fig. 9).

Accordingly, in the process of switching from the phase-change step 1 to the phase-change step 2, the delay of the phase current switching to the phase-change time points of the plurality of the stators 11 can be compensated.

The phase current switching unit 130 may switch the phase of the stator 11 based on the number of phase change pulses counted by the encoder 120 and the number of phase advance pulses calculated through the objective function, .

Here, if the number of phase change pulses counted during the phase change step is accumulated and recorded every time the phase change step is switched, a problem may arise in providing the reference for the phase advance angle control time point.

The phase angle is calculated according to the rotation speed of the BLDC motor 10 through the objective function. If the phase angle pulse number is continuously applied to all of the phase change steps, the BLDC motor 10 is driven by the external force The rotational speed of the current BLDC motor 10 does not correspond to the number of leading angular pulses that are currently applied when the rotational speed is changed according to a power condition or a user control condition for controlling the BLDC motor 10, A problem may arise in compensation of the phase current delay for the phase change between the stator 11.

Therefore, when the phases of the plurality of stators 11 are completely switched, the phase angle control time determination step S200 determines whether or not the phases of the stator 11 and the stator 11 of the BLDC motor 10, which are calculated by the objective function, It is possible to derive the number of phase angle pulses corresponding to the phase angle corresponding to the rotational speed and to re-arrange the control phase of the phase angle according to the rotational speed of the BLDC motor 10 after completion of the phase change.

When the phases of the plurality of stators 11 are completed, the phase angle control time determination step S200 may count the number of phase-change pulses in the initialized state through the encoder 120 have.

Accordingly, the phase angle according to the rotational speed of the BLDC motor 10 can be derived at each phase changeover step of the plurality of stators 11 through the phase angle control time determination step S200, The control unit 100 can more accurately control the control point of the leading angle with respect to the rotational speed of the BLDC motor 10. [

According to the method for designing the phase angle controller 100 according to the embodiment of the present invention, in order to compensate the drive of the BLDC motor 10 for the phase current switching delay, the phase change step of the BLDC motor 10 can be more accurately The phase angle of the phase angle can be derived using the encoder 120 which can be detected, and therefore, the phase angle of the phase angle of the stator (11) The controller 100 can be designed.

Further, since the simplified objective function is used in deriving the phase angle, the phase angle controller (hereinafter referred to as " phase angle controller "), which can calculate the phase angle corresponding to the rotational speed of the BLDC motor 10 at a higher speed, 100) can be designed.

Further, in deriving the control point of time of the phase angle, the control point of time of the phase angle is derived from the initialized information at each phase change step of the stator 11, It is possible to design the phase angle controller 100 capable of switching the phase currents of a plurality of the stators 11 at a more accurate phase angle control timing by dispensing disturbances that may affect the phase angle controller.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. . It is therefore to be understood that the modified embodiments are included in the technical scope of the present invention if they basically include elements of the claims of the present invention.

10: BLDC motor 11: stator
12: Rotor 110:
120: Encoder 130: Phase current switching unit
HA, HB, HC: Hall sensors

Claims (11)

A phase advance angle controller design method for controlling a phase angle of a BLDC motor for rotating a rotor in accordance with a phase change step of a plurality of stators, including a phase angle operation unit, an encoder and a phase current switching unit,
An objective function derivation step of deriving an objective function that can be calculated according to the rotational speed of the BLDC electric motor at the phase angle calculated by the phase angle calculation unit;
Wherein the encoder counts the number of phase change pulses counted during the phase change step and derives the number of phase advance angles that is the number of pulses corresponding to the phase angle calculated through the objective function, A forward phase angle control time determining step of determining the phase angle of the leading phase angle in the phase switching step through the number of phase angle pulses; And
Calculating the phase angle through the objective function derived from the objective function deriving step, determining the control time point of the phase angle from the phase angle control time determination step, And a phase advance angle controller designing step of designating a phase advance angle controller to switch the phase currents of the plurality of stators so as to compensate for the delay of the phase current switching for phase change of the plurality of stators,
The objective function deriving step may include deriving a phase voltage waveform of the BLDC motor using a Fourier series
Figure 112016111039062-pat00009
Wherein said target function is derived from said target function.
* ω e is the electrical angular velocity of the BLDC motor, b n is the coefficient of v (t)
Figure 112016111039062-pat00010
, v (t) is the sum of sine waves as a periodic function, and t is time. delete The method according to claim 1,
The objective function derivation step derives the objective function expressed by the phase angle of the first equation with respect to the magnitude and weight of the phase current delay for each term of v (t)
Figure 112016111039062-pat00011
- Formula 1
Figure 112016111039062-pat00012
- The second equation
Wherein the objective function is subjected to curve fitting to simplify to the second equation.
ω e is the electrical angular velocity of the BLDC motor, L is the phase angle of the rotor due to the winding itself of the stator, c n / N is the weight, tan -1 (nLω e / R) is the phase delay of phase- inductance, R is resistance, and k1 and k2 are constants for determining a curve fitting, dθ is the fast each, dθ is a truth each showing a simplified dθ of the stator. The method according to claim 1,
Wherein the phase angle controller designing step includes switching the phase currents of the plurality of stators prior to the phase change of the plurality of stators through the phase current switching unit when the number of phase change pulses counted by the encoder reaches the number of phase- Wherein the phase angle controller is designed to correct the driving of the BLDC motor with respect to the phase current delay. 5. The method of claim 4,
Wherein the phase angle controller designing step designates the phase angle controller to switch the phase currents of the plurality of stators by controlling the application of a current to the stator to be excited by the phase change through the phase current switching unit, Design method. 6. The method of claim 5,
Wherein the phase angle controller designing step includes switching the phase currents of the plurality of stator through the phase current switching unit by a delay of phase current switching to a phase change point of time of the plurality of stator phases, Wherein the phase angle controller is designed to switch the phase currents of the plurality of stators at a time point. The method according to claim 1,
The step of determining the phase angle control time may include detecting phase transition completion of a plurality of the stators through an electrical signal for detecting a magnetic pole of the rotor provided from a hall sensor for sensing a magnetic pole of the rotor, And the control point of time of the phase angle in the phase change step is determined through the encoder which counts the number of phase change pulses during the phase change step on the basis of the completion of switching and derives the number of phase advance angles The method of designing each phase controller. 8. The method of claim 7,
Wherein the phase angle controller designing step controls the current to be applied to the stator according to a predetermined truth table by the stator to which current is applied based on the electrical signal provided from the hall sensor through the phase current switching unit, Wherein the phase angle controller is designed to switch phase currents. 8. The method of claim 7,
Wherein the phase angle control time determination step comprises:
And a controller for detecting the phase change completion of the encoder or a plurality of the stators capable of counting the phase change pulse number by rotating with the rotor to detect the rotation state of the rotor, Wherein the controller determines the control point of the leading angle according to the rotation speed of the BLDC motor through the encoder by detecting the rotation speed. 8. The method of claim 7,
When the phase switching of the plurality of stators is completed,
Wherein the step of determining the phase angle control point re-derives the phase angle pulse number corresponding to the phase angle corresponding to the rotational speed of the BLDC motor calculated by the objective function through the encoder, And the control point of the phase angle is synchronized with the rotation speed. 8. The method of claim 7,
When the phase switching of the plurality of stators is completed,
Wherein the phase advance angle control time determination step counts the number of phase change pulses to an initialized state through the encoder to provide a reference of the phase angle control phase in the phase change step after completion of phase change, Each controller design method.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20180067029A (en) * 2016-12-12 2018-06-20 현대자동차주식회사 Lead angle controller
KR20200110747A (en) * 2018-03-07 2020-09-25 광동 메이디 컨슈머 일렉트릭스 매뉴팩쳐링 컴퍼니 리미티드 Food processor and control method and apparatus for increasing the rotational speed of the food processor
CN117477996A (en) * 2023-12-26 2024-01-30 深圳曦华科技有限公司 Motor control method, apparatus, computer device, and storage medium
CN117477996B (en) * 2023-12-26 2024-04-30 深圳曦华科技有限公司 Motor control method, apparatus, computer device, and storage medium

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20090082595A (en) * 2008-01-28 2009-07-31 삼성전자주식회사 Method for driving BLDC motor

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20090082595A (en) * 2008-01-28 2009-07-31 삼성전자주식회사 Method for driving BLDC motor

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Bon-Gwan Gu 외 2명. Simple Lead Angle Adjustment Method for Brushless DC Motors. Journal of Power Electronics, Vol. 14, No. 3, pp. 541-548, May 2014* *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20180067029A (en) * 2016-12-12 2018-06-20 현대자동차주식회사 Lead angle controller
KR102654914B1 (en) 2016-12-12 2024-04-03 현대자동차주식회사 Lead angle controller
KR20200110747A (en) * 2018-03-07 2020-09-25 광동 메이디 컨슈머 일렉트릭스 매뉴팩쳐링 컴퍼니 리미티드 Food processor and control method and apparatus for increasing the rotational speed of the food processor
KR102319867B1 (en) * 2018-03-07 2021-10-29 광동 메이디 컨슈머 일렉트릭스 매뉴팩쳐링 컴퍼니 리미티드 Control method, apparatus for increasing the rotation speed of food processing machine and food processing machine
CN117477996A (en) * 2023-12-26 2024-01-30 深圳曦华科技有限公司 Motor control method, apparatus, computer device, and storage medium
CN117477996B (en) * 2023-12-26 2024-04-30 深圳曦华科技有限公司 Motor control method, apparatus, computer device, and storage medium

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