TW483231B - Brushless DC motor control method for adjusting phase-change timing based on the rotating speed - Google Patents

Abstract

The present invention relates to a brushless DC motor control method capable of adjusting the phase-change timing based on the rotating speed. Based on the motor rotating speed, the phase-change timing of the brushless DC motor is determined and adjusted. The change of the current phase of the motor generates phase advance and field weakening control effects. Therefore, the motor can output best torque at any rotating speed in a normal rated rotating speed range. To operate in a high rotating speed range, it is able to greatly increase the highest rotating speed limit of the motor without modifying the motor body and related driving hardware apparatus.

Description

483231 A7 B7 5. Description of the invention (The present invention relates to a brushless DC motor control method that adjusts the commutation timing according to the speed, especially a brushless DC motor as a control object, combined with a magnetic pole position sensor or other types. The position sensor is used for rotor position sensing and speed estimation, and in conjunction with pulse width modulation (PWM) switching technology and digital control technology, the brushless DC motor generates phase advance and field weakening effects, among which phase The advanced control can make the motor have ideal torque output in each speed range, and the field weakening control makes the motor have a larger speed range. Press to make the brushless motor have ideal torque output in various speed ranges, and Provide a larger speed range, which can be achieved by using phase advance and field weakening control technology. For example, brushless AC Motor or Permanent_Magnet Syschronous Motors (PMSM) are used in combination with precision position encoders. (Encoder) or Resolver for phase advance and field weakening control, but this method must use a precision rotor The sensing element is installed, so the implementation cost is high, and it is not suitable for the brushless DC motor driven by rectangular current. The specific technical background of the foregoing is described as follows. The brushless motor can be divided into the back-EMF waveform or the applied current method. : Permanent Magnet Synchronous Motor (permanent—Magnet Syschr 00us 〇〇〇α, PMSM) and Brushless DC Motor (Brushiess Dc Motor, blj) cm). Among them, the permanent magnet synchronous motor has a sine wave back electromotive force, and can cooperate with the sine wave stator current control to generate a constant torque; while the general brushless DC motor has a trapezoidal wave back electromotive force, a rectangular stator current is required to generate a constant torque. . And the permanent magnet synchronous motor is under the traditional a-b-c axis coordinate, its dynamic mode (please read the precautions on the back before filling this page) ------ Order ------ A7

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I! 483231 A7 B7 V. Description of the Invention ()) (Ksy

cos6 ^ sin cos cos (2πλ (2πλ Α-sin A- ^ 3) (Ύπ, (2πλ must + α sin V 3) ^ 3 J

Vq Second see q + + cosAd ν ^ ΚΙά + Ολά-ωλ where K ^ LdId K: Θ axis equivalent voltage vd: d axis equivalent voltage R: armature resistance per phase: Θ axis equivalent current Id : d-axis equivalent current D: Differential operator (々 治) ①s: Stator converter angular frequency: Θ-axis inductance Ld: d-axis inductance This paper is applicable to China National Standard (CNS) A4 (210 X 297 mm) ) (Please read the notes on the back before filling this page)

I! I 483231 A7 B7 V. Explanation of the invention (meaning) Λ Λ

.Rotor magnet to stator flux chain • 7 axis flux key ^ axis flux key Based on this, the torque equation of the motor is 3P

Te may be expressed as T 2 x m q and the dynamic equation of the motor is D (O, ^ < Te—TL—B 2

3P, Ld-Jq) (Please read the precautions on the back before filling this page) where Te: electromagnetic torque TL: load torque P • magnetic pole pair ①r • rotor speed [① • viscosity friction coefficient person: rotor inertia Ρων Order ------ j —— ^ 9. It can be seen from the torque equation that the allowable system is generated by the permanent magnet as a value of 疋 '. If the order = 〇, then the above formula shows that the electromagnetic torque is 7 ;proportional to. Under the dynamic control of Emperor Sun Shou ’control to zero, copper loss caused by no

U 483231 A7 V. Description of invention (Γ) rate. Adjusting the heart value can directly control the electromagnetic torque ^ to achieve the best transient torque response. At this time, 々 can be regarded as a torque current component, and &quot; can be regarded as a magnetic: current component. When the permanent magnet synchronous motor is operated within the rated speed, the key to torque holding is to make the d-axis component of the motor zero, that is, to reasonably allocate i ^ w and the electric drag current to make its composite vector ⑽ overlap. This: electromagnetic rotation Moment? ; The size is completely controlled by (to get the ideal torque control. However, when the permanent magnet synchronous motor wants to run above the rated speed, it must be achieved by field weakening technology. At this time, it must be controlled to make the overall magnetic The chain is reduced to achieve the purpose of "weakening magnetic field" control, and the permanent magnet synchronous motor has more electromagnetic torque to increase the speed at higher speeds. Regardless of the control / factory 0, the electromagnetic rotation The moment is optimally controlled, and the control / <0 achieves the field weakening effect, which makes the motor run at a higher speed. Li Li = wide: Bu, 7. The magnitude of the three-phase electrical frame current: conversion field, 0,?. However, this method is not applicable to brushless DC motors, mainly because the brushless DC motor has only two phases conducting at any moment, and the two-phase currents are equal, which is not feasible for the aforementioned control method that must be distributed at the same time. For a brushless DC motor, the back-EMF waveform is close to a wave, and the more suitable driving method is 12G. It is turned on and controlled in conjunction with the touch to: Generate a rectangular current waveform and obtain a fixed wheel output torque.% In Position sensing device Surface 'brushless DC motors-generally use Hall elements for rotor position sensing, the commutation sequence depends on the rotor position signal to the Hall element, the magnetic pole signal is amplified and the appropriate logic is scaled for China Standard (Please read the notes on the back before filling this page)

• nnnnnnn IIIIIII -nu VI '483231 A7 V. Description of the invention (6) circuit, output the relative commutation signal to the driver stage, and control the power-driving switching element of the rear stage; for a rectangular current drive system, there are two The two switching elements actuated to excite the two-phase coils in the motor stator, and then the coils are sequentially excited to generate a rotating magnetic field. Figure 9 shows a schematic diagram of a brushless DC motor (80) and its driving circuit. The switching elements n, T3, and T5 are generally referred to as the upper arms of the drive stage, and T2, T4, and T6 are the lower arms. Refer to the tenth figure for the operating sequence of each switching element and the corresponding direction of the rotating magnetic field of the stator. You can switch in the order of η and D4, U and T6, T3 and T6, T3 and T2 to obtain a rotating magnetic field in the clockwise direction (in the counterclockwise direction) , The switching sequence is the opposite), when switching, the upper arm (or lower arm) can do simple switching at the same time to control the current value. Under normal circumstances, the relationship between the electrical torque generated by the motor and the three-phase current and back-EMF waveforms is shown in Figure 11. As shown in the eleventh figure, it is the actual measurement result of the counter-EMF and Hall signal alignment waveforms of a high-speed electric motor vehicle. Based on the measurement results, the electromotive force wave 幵 / approximate trapezoidal wave is displayed, and the Hall signal is compared with Back electromotive_ found a fixed about 30 between the two. (Electrical angle) Phase Super rigid angle, that is, when the Hall signal transition is received, if the phase is changed immediately, it is equivalent to f 30. (Electrical angle) commutation. This makes the motor have a relatively high torque output in the middle and high speed regions. A code t ^ ^ ^ is an inductive i load, = when there is a voltage first, and then a current is generated, that is, the position of the excitement is broadcasted on the right, and the current angle is dredged by the j-angle meeting, A4 uu, .. i Current current counter 297 mm) (Please read the precautions on the back before filling this page) IIII · I--I — 111. 483231 A7 V. Description of the invention (. When the thunder phase is in phase, it can be the fullest m. When the thunder phase is ahead, the Pan current compensates for the backward ^ AjlAjl current and the anti-electrical current in the same phase. In the torque output speed zone, this phase of Ma Wei's solid state Zhao Qianjiao reduces the motor's wheel torque. Generally, after comparing the Hall signal of a non-high-speed motor with the back-EMF waveform, the voltage lead angles are all It is fixed (most of them are 0.), that is, when the 雈 尔 # is transferred to sadness, if the phase is changed immediately, the low and middle speed current is almost in phase with the voltage. At this time, there is a large torque output. However, as the As the motor speed increases, the more the phase of the current lags behind the voltage, the larger the phase difference between the current and the back-EMF waveform, and the torque output effect will change. . From this we can see that the timing of commutation is fixed (that is, the electric forward angle fixed at the DC horse stables can not be combined with high speeds. ”Higher ratchet moments. (Please read the precautions on the back first (Fill in this page again) ------- Order ---------, 'Two Return ,,,' The control methods of brushless motors described in the following can be summarized as follows:

Think-torque output! ^ Method taking into account low, medium and high speed

Method, can only make J company JS self-sufficient farmer ^ a weak Wei system, the torque can be thought of. 1 high shame speed man-shaped thunder current body. DC horse monument. Therefore, from the above, it can be known that 'there is a brushless motor control method and it is obvious that the paper size needs to be entered. This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 483231 A7 ______________B7__ 5. Description of the invention (y) Check the time 'and seek an effective improvement plan. Therefore, the main objective of the present invention is to provide a brushless DC motor control that can make phase brushless and field weakening effects without requiring precise position coding or angle resolver. Method, which can make the motor have better torque output in each speed range, and when a higher speed is needed, the maximum speed capability of the motor can be improved. The main technical means adopted to achieve the foregoing purpose is to control the commutation timing according to the motor speed. The specific method is: The control of the phase advance is at any speed within the rated speed of the motor. After the signal transitions, the phase commutation is delayed with an appropriate delay time (as shown in the fifth figure) to control the voltage phase (voltage lead angle) of the motor. Then, the current phase of the backward current can be controlled to be in phase with the back-EMF of the motor, so that the motor can produce a better torque output; while changing the commutation delay time, the voltage phase can be changed and the backward current phase can be driven to change. The field weakening control part is to make the motor have a wide speed range. It is mainly achieved when the motor is operated above the rated speed by making the current phase moderately ahead of the back-EMF phase by the aforementioned method. In order to make your reviewers better understand the foregoing objectives and the technical features of the present invention, detailed drawings are attached as follows: (1) Schematic part: The first figure: is a schematic diagram of the hardware structure of the present invention. The second figure is a schematic diagram of the motor speed estimation of the present invention. · 10 paper sizes are applicable to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page) -n ϋ n κ ϋ n- ^ OJI nn «ϋ dn i_i A7 B7 V. Explanation of the invention (?) The first picture is a comparison diagram of the signal of the back-EMF of the motor of the present invention. The fourth figure is a sequence diagram of the Huo Buboer signal and the exciting coil in the normal operation of the present invention. The fifth figure is a schematic diagram of the principle of voltage lead angle regulation of the present invention. Fig. 6 is a timing diagram of the _㈣ signal and the exciting coil when the present invention makes a large phase advance. Figure 7 is a phase control line chart of the present invention. The eighth diagram of the m permanent magnet synchronous motor adopts the d_q axis conversion method of the rotor coordinate diagram. / Can Picture 9: The conventional brushless DC motor and its picture. The tenth graph: is the comparison diagram of the brushless DC motor switching sequence and the stator rotating magnetic field. Figure 11: The relationship between electrical torque, three-phase voltage and back-EMF of a conventional brushless DC motor. The twelfth picture is a comparison diagram of the back-EMF and Hall signal of a conventional brushless DC motor. 〇 化 (二) Drawing No. part: (1 0) Motor (1 2) Rotor measured motor torque-speed relationship curve Schematic diagram of swing circuit Circuit (Please read the precautions on the back before filling this page}

T,. -N n n an n «I ^ I n til im m n ϋ aMmmam I (11) stator (2 0) drive circuit (3 0) digital signal processor (3 1) edge trigger signal acquisition order

Yuan (3 2) digital I / O (3 3) phase controller 11 This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)

V. Description of the invention (/) (34) pwm control unit (40) Hall element (35) timer (80) brushless DC motor The purpose of the effect to be achieved by the present invention is as described above, It mainly produces effects such as phase advance and field weakening control in the brushless DC motor. Among them, the control method of the phase advance is as follows: when the motor is running at the rated Korean speed, the license holder (30) will receive a trigger letter on the edge of the motor according to the speed of the motor). After the Hall signal is in the Korean state, the phase is also phased (voltage Zhao Qianjiao) with the appropriate Yanma time, and the #EMF is in phase. And changing the commutation delay time can change the phase of Ai voltage and drive the change of the backward current phase. Under the condition that the current phase and the back-EMF of the motor are in the same phase, the motor can produce a better torque output at any speed within its rated speed range. In addition, there is a wide range of ratchet speeds, which are for horse control. (3, the motor can be rotated at the rated speed. As for the hardware structure used to implement the foregoing method, please refer to the first figure, which includes: a brushless DC motor (10), Including the stator (11) with three-phase coil windings and the rotor with different magnetic poles (12y; 12) This paper size applies to China National Standard (CNS) A4 specifications (210x 297 public love) (Please read the precautions on the back before filling this page )

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V. Description of the invention (/; a drive circuit (20), read 彳!% 丄 口 ,, 过 ,, and group of electronic switches to control the current through the stator 1 respectively), in this% inconsistent yoke example, 6 The electronic opening relationship of the group is composed of transistors τ 1 ~ Τ 6;-the digital signal processor (30), the output end of which is a simple control sent by a simple signal to control the on and off of six groups of electronic switches in the drive circuit (20) ; Its input end is to obtain the position signal of the aforementioned rotor (1 2) through a -Hall element (4 Q), and calculate the motor speed with a timer (3 5). Wherein: the digital signal processor (30) includes at least an edge-triggered signal acquisition unit (31) connected to the output end of the Hall element (40), a digital I / O (3 2), and a timer (3 5 ),-The phase controller (3 3) and a control unit (3 4) that controls each electronic switch in the drive circuit (2 ◦). The output signal of the Hall element (40) is directly connected to the edge trigger signal acquisition unit (31) in the digital signal processor (30). The edge trigger signal acquisition unit (31) can The detection Hall element (4 0) sends trigger signals of positive and negative edges, and sends an interrupt signal. When the interrupt occurs, it indicates that the Hall element (4 0) detects the position change of the rotor (丄 2), and at this time Cooperate with a digital 1/0 (3 2), read the level of Hall's signal for correct commutation. And the digital signal processor (30) has a timer (3 5) built-in. , As the time reference of the edge trigger signal acquisition unit (3 1) to cooperate with the calculation of the motor speed and current phase control. In this embodiment, the timing frequency is set to 20M // Z / 128. Clock pulse wave count value (13 pieces of Xunyou factory, the scale of the scale is applicable to China National Standard (CNS) A4 specification (210 X 297 mm) ------------------ --Order --------- line ^^. (Please read the notes on the back before filling this page) 483231 A7 of which η CAP0 CAPn Tc V. Description of the invention (value), Will be recorded in the timing of crying (Dingkou's FIFO stack (First In

First Out Stack, FIFO stacks d, _ clCK), and set the corresponding interrupt flag, which indicates that the edge trigger signal capture mask Yashanshan "take early Fan (3 1) receive trigger signal interruption; and the FIFO stack right One layer of 'one layer' records the old count value in the upper layer 'and the new count value has been recorded in the lower layer s. Each time a person is read, the upper layer is read first, and the lower layer is automatically squeezed upward. Jin, #, τ ^ in the FIFO stack sale The difference between the two count values represents a time passing by the Hall transition # ^ Γ1 can be used as the basis for the speed estimation. The timing diagram of the speed estimation is as shown in the first-Le-diagram, three-phase four-pole The output signal of the Hall element (40) rotates twelve times for every revolution of the motor. In accordance with the inertia of the motor rotor and the load, the accuracy of the second speed sampling of each material is acceptable. Obtained: ^ — 60 ”-one (_) Motor speed (rpm) Count value when the old edge trigger signal is interrupted Count time when the new edge trigger signal is interrupted (6 · 4χ1〇_ό seconds) Or, the aforementioned phase control completed by software One of the functions of the controller (3 3) is to adjust the optimal phase advance angle according to the speed of the motor when the motor is running within the rated speed, so that the current phase can be in phase with the back-EMF. As for the comparison diagram of the motor's back-EMF and Hall signal, please refer to the third figure (please read the precautions on the back before filling this page) • nnnnnnn ^ OJff n I nn. 14 V. Description of the invention (丨) Example In the normal operating state, each set of coils of the motor stator is sequentially excited, and the voltage phase will be 'fixed ahead of the back EMF 30. (Electrical angle) (coordinated with the fourth figure), the phase of the current lagging voltage increases with the increase of the motor speed. If the speed is high, it is enough to make the current lag behind the voltage by 30. (At this time, the current and the back-EMF are in phase), the maximum torque effect will be produced. However, if the motor is running at a slower speed, the aforementioned fixed value is 30. Leading the angle will cause the current phase to lead the back EMF, but it will not be able to generate large torque. In order to solve the foregoing problem, the present invention utilizes an edge-triggered signal acquisition unit (3) of the digital signal processor (30) to adjust the delay inversion after receiving the Hall transition signal, in cooperation with the timer (3, 5). The timing of the commutation operation is such that the voltage lead angle of the motor in this embodiment is controlled to -30 as the motor speed changes. To 30. between. This is the main work of the phase controller (33). As shown in the fifth figure, it is a schematic diagram of the working principle of the phase controller. When commutation and excitation are delayed. In this case, it is equivalent to a voltage lead angle of 30. , Commutation and excitation delay 30. In this case, it is equivalent to a voltage lead angle of 0. The rest is the same. The better lead angle in each speed range can be summarized by the torque-speed and efficiency-speed characteristics of the measured results. According to the normal operation sequence of the fourth figure, and the delayed commutation of the digital signal processor (30), the voltage lead angle can be zero. To 30. If there is no step regulation, if a larger voltage lead angle is needed to cope with a faster motor speed, the commutation sequence of the sixth figure can be used instead (the excitation sequence of the coil windings is changed at the same time using the same delay principle to make the motor The voltage lead angle is controlled at 30. 15 V. Description of the invention (#) to 90. 'Phase can be made to a greater extent. When the seventh picture is not Duty = 1, change the voltage lead 旲 ...: torque A speed relationship curve, the solid line is the measurement--, ..! Is a programmable torque-speed relationship curve: The symbol of = should be shown in the figure. It can only be operated in the rated speed range. Its maximum angular electrical overshoot has not been increased due to the increase in voltage lead angle, that is, the maximum speed is about Γ7Γ. At this time, the load and friction are about 5kg_em. Taking the torque ', it can be found that when the speed is getting higher and higher, the voltage is over = maximum, and there is a significant increase. When it is called L◦, the voltage is increased by k ^ 'Ik, the speed of the current increases, and the current phase will start to lag behind. The maximum torque will decrease accordingly. At this time, if the voltage river angle is matched with the speed, the current phase will be driven. If the back-EMF is in phase, the maximum torque can be increased again. The results are shown in the first section, the head position is advanced, as shown in the part, and therefore the theory of the phase control is verified. ηRu seventh figure, when the voltage lead angle is 45. Began to increase to 70. It starts to increase significantly when it takes a large speed. It can be increased from the original 8 · rpm to 144GG coffee. If the voltage lead angle continues to increase, the maximum speed will also be affected by the aforementioned weak field control β. &quot; Then, you can check the effect * The effect of the present invention on the weak control of the brushless DC motor. It can be seen that the present invention is indeed feasible in terms of descriptions, and that such arrangements have at least the following advantages. · 16 (210 x 297 mm) 483231 2. A7 5. Description of the invention (/ Γ) Under the original motor structure and drive circuit, phase advance and field weakening control can be achieved through appropriate software planning to 'change different voltage lead angles.' By changing the voltage lead angle, the current phase is in phase with the back-EMF of the brushless motor to achieve phase lead control, which can increase the output torque of the motor and achieve the best torque effect at different speeds. H Conventional brushless straight drop fixed commutation timing | The method of humiliation takes into account the shortcomings of the best spines at low speeds. 3. By changing the voltage lead angle to make the current phase moderately lead the brushless motor back-EMF ', the field weakening effect can be achieved, and the motor speed can be reduced to the original rated speed. 4. The technology of the present invention to achieve field weakening control is different from the known skin magnetic @

It can be achieved without the use of a device or solution angle ^ AJLjL sine wave current medium difference synchronization horse jp. At the cost F. In summary, the present invention can indeed achieve the advantages as described above. Compared with the traditional brushless DC motor control method of fixed commutation timing, better torque output and efficiency can be obtained in different speed ranges, and when higher speed% is required, it can also provide output higher than the rated speed in a timely manner. , And does not need to change the original motor structure and drive-level circuit, so it has both industrial applicability and progress, and meets the requirements of invention patents, filed an application according to law. 1. For those who need to know, the above is a better and concrete implementation of the present invention. The paper size is applicable to the CNS A4 specification (G X 297).

(Please read the notes on the back before filling this page) -------- ^ --------- ^ 483231 A7

V. Explanation of the invention (4) The functions and effects produced by it shall still be within the scope of the present invention. If the changes made according to the concept of the present invention do not exceed the spirit covered by the description and illustration, they shall be shared with Chen Ming. 18 This paper size applies to China National Standard (CNS) A4 (210 X 297 public love)

Claims (1)

483231 Printed by the Consumers 'Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, and the date of printing is supplemented with 90.11 A8 B8 C8 D8 Patent Application Scope 1. A brushless DC motor control method that adjusts the commutation timing according to the speed.' When the motor is within the rated speed range , Indirectly controlling the current phase, so that it can be in phase with the motor's back-EMF, so that the motor can produce the maximum torque output at any speed within its rated speed range; that is, at high speeds, the motor is made the same way The current phase is moderately ahead of the back-EMF phase to achieve field weakening control, which allows the motor to run above the rated speed to expand the speed range. 2 · According to the brushless DC motor control method of adjusting the commutation timing according to the rotation speed as described in item 1 of the scope of the patent application, the current phase is controlled by adjusting the voltage overshoot angle, that is, calculating the rotation speed of the motor according to the Hall transition signal. After the Hall signal transitions, Asia commutates with a proper delay time to control the voltage phase of the motor; changing the commutation delay time can change the voltage phase 'and drive the current phase behind. 3 As described in the first or second item of the patent scope, the brushless DC motor control method of adjusting phase commutation Yin 2 according to the rotation speed. The range of this current phase change depends on the placement position of the element, and can generally reach 60. The electrical angle, the phase of this range, and the phase difference can be achieved by changing the coordination of the commutation timing. J4. The brushless DC motor control method for adjusting the commutation timing according to the rotation speed as described in item 1 or 2 of the scope of patent application. The use control device includes: 1. Drive circuit that controls the current flow through multiple sets of electronic switches. The coil windings of the motor stator; ★ The digital 仏 processor sends a P-lane signal at the output to control the on / off of each group of electronic switches in the fast circuit; its input terminal is to obtain the motor speed signal through the -Hall element; Among them ... (Please read the precautions on the back before filling in this page) n II 1 I -1 I nn 1 ----— 19 This paper rule is based on 483231 patent application scope Touch 1 The digital signal processor includes a connection The edge of the output end of the element, the poisonous ^ number extraction unit, the number # I / Q, — a timer, — a phase controller with a control voltage exceeding 4 angles, and an electronic PWM control unit that controls the drive circuit. 幵 关 之 5 Adjust the commutation timing according to the rotation speed as described in item 4 of the scope of patent application = brush DC motor control method, each group of electronic opening relationship is controlled by a transistor 6. Adjust the rotation speed as described in item 3 of the scope of patent application A brushless DC motor control method for commutation timing. The use control device includes: a driving circuit that controls current through each coil winding of a motor stator through a plurality of groups of electronic switches; ordering a digital signal processor whose output terminal Send a simple signal to control the on / off of each group of electronic switches in the drive circuit; its input end is to obtain the speed signal of the motor through the Hall element; where: the digital signal processor includes an edge trigger signal connected to the output end of the Hall element Operating unit, -magic / Q, -timer, a control unit [phase control s of super angle and PWM control unit that controls each electronic switch of the drive circuit. 7.Please refer to item 6 of the patent scope The brushless DC motor control method that adjusts the commutation timing according to the speed, each group of electronic opening relations is composed of a transistor.