TWI222782B - Phase-locked speed control device of three-phase brushless DC motor and method thereof - Google Patents

Abstract

The present invention discloses a phase-locked speed control device of three-phase brushless DC motor and method thereof, wherein the feedback signal of motor speed and rotation speed command signal pass through the automatic frequency correction circuit and automatic phase correction circuit, and generate the frequency error and phase error respectively. Both errors are added by an adder, and are computed by loop filter to obtain a new control signal. The feedback signal of the rotation speed is processed by a frequency divider circuit, so as to avoid the feedback error of rotation speed. In addition, the loop filter generates a new control signal which passes through the pulse width modulator and sequencer to generate a switch signal, so as to control the armature voltage of motor for correcting the motor speed, thereby the motor speed can be controlled.

Description

12 meetings, one replacement

Amendment No. 92109668 V.—Day 1. [Technical Field to which the Invention belongs] The present invention relates to a control technology applied to Three-Phase Brushless DC Motors, especially to a two-phase brushless DC Motors. Phase-locked speed control device and method for brush DC motor. 2. [Previous technology] According to 'Brushless DC (BLDC) motor has the advantages of high efficiency and low price', it has been widely used in piezoelectric motors such as camera lens autofocus, voice coil motors of optical disk drive read heads, and optical disk drives. Information equipment such as spindle motors, home appliances, and electric vehicles. What is a brushless DC motor is the one that replaces the brush and commutator functions of the original DC motor with electronic circuits such as Hall elements. It has the advantages of DC motor and AC motor. The two-phase brushless DC motor uses the Hall sensor to feedback the rotor position of the motor, so only the feedback signals Hu, Hv, and HW from the Hall sensor can be used to estimate the speed of the motor for speed control. . However, the feedback signals HU: HV and HW are three square wave signals with a phase difference of 120 degrees. After passing through the x0R digital logic circuit, a three-frequency pulse wave signal can be obtained. This signal is generally called FG. The three conventional brushless DC motor control methods generally use a counter to count the pulse wave of the FG signal as the speed feedback signal. Its precision is quite poor, so the control effect is not good. Therefore, such as feeding; Processing FG signals to obtain higher speed feedback precision has become a development trend. ^ m For example, the estimation of the radial speed of the disc in Chinese Patent Bulletin No. 485339, which proposes a speed control method for a three-phase brushless DC motor. ^ The pre-patent case uses a counter to count the pulse wave width of the FG signal. , And the soil degree is determined by the reference clock of the counter. When applied to higher precision: page 5

In this case, the precision of the counter can be improved by increasing the reference clock of the counter. However, the pre-patent case No. 485339 only uses the frequency information of the FG signal for speed control. Once the frequency of the FG signal is the same as the speed command signal fr, the speed control is completed, but this control method does not guarantee that the motor is smooth, Stable operation, and when there is a sudden external force interference, it takes a long time to recover. Therefore, the present invention proposes a three-phase brushless DC motor phase-locked speed control device and a method thereof in order to overcome the above-mentioned problems, so as to effectively overcome the defects existing in the prior art. 3. [Content of the Invention] The main purpose of the present invention is to provide a three-phase brushless DC motor phase-locked speed control device and a method thereof, which use a special circuit to process the feedback signal of the Hall sensing 7C component to increase the rotation speed. The accuracy of feedback, combined with the phase-locked speed control technology, improves the precision and stability of the three-phase brushless DC motor speed control. Another object of the present invention is to provide a three-phase brushless DC motor phase-locked speed control device and method thereof, which can ensure that the motor runs smoothly and stably, and the signal does not drift arbitrarily. Another object of the invention is to provide a three-phase brushless DC degree control device and method thereof, which are used to detect a phase error in a digital phase-locked manner in the presence of external force interference. The detection method can more accurately and quickly detect the response of small speed changes. The stated purpose is to include a three-fold frequency decoding circuit.

: Under the same conditions, the degree control loop can achieve faster and faster speed compensation control action.

The hall sensing element feedback signal is sent to the pulse wave. An automatic frequency correction command is used to make the signal and the speed commutation controller use a wave filter according to whether the self-position error amount is activated. It is a control signal. Furthermore, the effect of the present invention can be easily understood below. 4. [The feedback signal of the embodiment is decoded into a pulse wave signal with a frequency of twice, and divided to obtain a frequency error of a turn circuit and an automatic phase correction feedback signal. The automatic frequency correction circuit generates a phase correction circuit. The motors are added to obtain a system for controlling the speed of the motor according to the total error amount. The embodiment is accompanied by the attached purpose, technical content, a sensor signal relative to the Hall, and a frequency-divided electric speed feedback signal. Then, the life and phase errors are respectively corrected by the positive circuit; and there is a lifetime frequency error amount, the output frequency error and the total phase error amount; and a calculation to generate a new purpose. The diagram explains in detail that when more features and the work achieved by the three-phase brushless DC motor, the Hall sensor element is used to detect the pole position, and then the motor speed is estimated based on the feedback signal from the Hall sensor element, and Compared with the speed command, speed control is performed; the method of estimating horse speed and the speed control method determine the level of control precision. There are two commonly used speed control methods in the mine. They are to use a counter to count the number of pulse waves and the pulse width of the pulse wave output by the frequency decoding circuit, estimate the i sub speed, and then compare it with the speed command for speed control. However, the control precision of this estimation method is not high, and the 3-degree lock control device and method proposed by the present invention will greatly improve the precision of the speed control, so as to solve the lack of the existing technology. The first picture shows the fighters of the phase-locked speed control device of the present invention.

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In the following, the method of the spot control of the speed control device of the present invention will be described in detail with reference to this figure. As shown in the first figure, a phase-locked speed control device 10 is connected to and controls the rotation speed of a three-phase brushless DC motor 30, and is estimated using the feedback signals (HU, HV, and HW) of the Hall sensing element. The rotation speed of the motor 30 is used for speed control. 'This phase-locked speed control device 10 includes a 3X decoder 12', which receives the feedback signal (HU, HV from the Hall sensing element). And HW), and decodes the feedback signal into a pulse wave signal with a frequency three times that of the feedback signal from the Hall sensing element; and a frequency divider 14 is connected to the triple frequency decoding circuit 1 2 'Frequency division circuit 1 4 Divides the pulse wave signal to obtain a speed feedback signal (FG), and because of this frequency division processing, the pulse wave signal is not subject to the error of the position of the Hall sensing element. And affect the pulse width of the pulse wave signal. Among them, the signal form of the speed feedback signal is ^ a pulse wave signal, which detects the position of the magnetic pole of the motor by the Hall sensing element, generates two square wave signals with a phase difference of 120 degrees, and passes through the three The frequency doubling decoding circuit 12 and the frequency dividing circuit 14 obtain this rotation speed feedback signal, and its frequency is one half of the frequency of the electrical angle change of the motor 30. The frequency dividing circuit 14 is connected to an automatic frequency correction circuit 16 and an automatic phase correction circuit 18. The two correction circuits 16, 18 except for receiving clock signals from the system In addition to (CLK) and speed command signal (FR), it also receives the speed feedback signal output by the frequency division circuit 14; among them, the automatic frequency correction circuit 16 corrects the command signal (FR) and speed feedback signal (FG) Frequency error to output a frequency error amount, and the automatic phase

Page 8 · mm,. ,,-;,. Amendment MM 92inQfifi «V. Description of the invention (5) 正 Position = ΓPosition The phase error of the command signal and the speed feedback signal U bit error [another commutation The controller ("itch bit correction is electrically connected to the automatic frequency correction circuit 16 and the automatic phase = the amount of frequency error generated to control whether the automatic phase correction is activated.") Then, an adder (adder) 22 is used to correct the automatic frequency correction. The frequency error amount output from 16 is added to the phase error amount output from the automatic phase correction circuit μ to obtain a total error #; and the total error amount of frequency and phase obtained by the adder 22 is passed through a loop filter (1 filter ) 24 to perform a calculation to generate a new control signal. The loop saver 24 generates a new control signal that can be passed through a pulse width modulator and sequencer 32 (PWM & seqUencer) 32 in order to Hall senses the three-phase signals fed back by the cow, and through its internal decoding circuit, it generates six switching signals to the motor controller 34, and then controls the voltage of the electrical frame voltage of the three-phase brushless DC motor 30 to achieve control. Motor 30 rpm After describing the structure and method of a complete phase-locked speed control device, the detailed structure of the above-mentioned automatic frequency correction circuit and automatic phase correction circuit will be described in succession. As shown in the second figure, this automatic frequency correction circuit It includes an edge trigger detection circuit (edge trigger) 162, which detects the occurrence time of the rising edge of the speed feedback signal (FG) and the command signal (FR); and then uses a frequency error judgment circuit (phase locked detector) 164 to determine whether it is within the set frequency error range; another debt measurement circuit 1 6 'is composed of a digital counter to detect the difference between the pulse width of the command signal and the speed feedback signal. This difference

92109668 Description of the invention (6) Month and month _correction It is the phase error under the same frequency condition. The automatic phase correction circuit 18 is shown in the third figure, which includes an edge trigger detection circuit 1 8 2 to detect the occurrence time of the speed feedback signal and the rising edge of the command signal; and then use a phase detection The test circuit 1 84 detects the relationship between the leading and trailing phase of the speed feedback signal and the command signal. The phase detection circuit 1 84 is composed of a D-type flip-flop; and a detection circuit 1 86 is used to detect Measure the phase error between the speed feedback signal and the command signal. The invention uses a three-fold frequency decoding circuit and a frequency division circuit to process, so that the frequency of the speed feedback signal is not affected by the position error of the Hall sensing element, so the accuracy of the speed feedback signal can be effectively improved; Phase-locked speed control technology 'improves the precision and stability of three-phase brushless DC motor speed control. In addition, when the rotation speed feedback signal and the rotation speed command signal are at the same frequency and in the same phase, the invention can ensure that the motor runs smoothly and stably, and the signal does not drift freely. When the external force interferes, the invention uses digital Phase-locking method detects phase error, which can detect the response of small speed changes more accurately and quickly than the conventional frequency error detection method. Therefore, under the same conditions, the speed control loop can achieve faster response to complete quickly. Action of speed compensation control. The above-mentioned embodiments are only for explaining the technical ideas and features of the present invention. The purpose is to enable those skilled in the art to understand the Uchiya of the present invention and implement the present invention. It should not be used to limit the present invention. The patent scope, that is, the equal changes or modifications made by Tuas in accordance with the spirit disclosed by the present invention, should still be covered by the patent scope of the present invention.

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B Modification Brief Description of the Drawings Description of the Drawings: The first drawing is a block diagram of a phase-locked speed control device of the present invention. The second figure is a schematic diagram of the structure of the automatic frequency correction circuit used in the present invention. The third figure is the schematic diagram of the structure of the automatic phase correction circuit used in the present invention. The figure illustrates: 14 frequency division circuit 162 edge trigger detection circuit 16 6 detection circuit 182 Edge trigger detection circuit 1 8 6 Detection circuit 22 Adder 10 Phase-locked speed control device 12 Triple frequency decoding circuit 16 Automatic frequency correction circuit 164 Frequency error judgment circuit 18 Automatic phase correction circuit 1 8 4 Phase detection circuit 20 Commutation controller 24 Loop filter 3 0 Three-phase brushless DC motor 32 Pulse width modulator and sequencer 34 Motor controller Page 11

Claims (1)

1222782 Rev. 92109668 dated June 6. Patent application scope 1. A three-phase brushless DC motor phase-locked speed control device that controls the rotation speed of a three-phase brushless DC motor and estimates it using the feedback signal of a Hall sensing element The rotation speed of the motor is used for speed control. The phase-locked speed control device includes: a three-fold frequency decoding circuit that decodes the feedback signal of the Hall sensing element into a feedback signal relative to the Hall sensing element. Pulse frequency signal of three times frequency; a frequency dividing circuit connected to the frequency doubling decoding circuit and frequency dividing the pulse wave signal to obtain a speed feedback signal; an automatic frequency correction circuit that corrects a command signal Frequency error with the speed feedback signal; an automatic phase correction circuit that corrects the phase error between the command signal and the speed feedback signal; a commutation controller that connects the automatic frequency correction circuit with the automatic phase f a positive circuit, and control whether to start the automatic phase correction circuit according to the frequency error generated by the automatic frequency correction circuit; The device is used to add an output error amount of the automatic frequency correction circuit and the automatic phase correction circuit to obtain a total error amount; and a loop wave waver, which performs calculations based on the total error amount to generate a new control signal To control the speed of the motor. 2.s The phase-locked speed control device as described in item 1 of the scope of patent application, the signal form of the § speed feedback signal is a pulse wave signal, and the position of the magnetic pole of the motor is detected by the Hall sensing element. Generate three phase 2 square wave signals, and pass through the three-fold frequency decoding circuit and the frequency-removal circuit Page 12 ::: At this speed feedback signal ’and its frequency is one half of the dagger neck rate of the electrical angle of the motor. The automatic frequency correction circuit in the phase-locked speed control device described in item 1 of the patent application scope of the order φ includes: a human-edge trigger detection circuit that detects the speed feedback signal and 7 the time when the rising edge of the signal occurs; two frequency error judging circuits to determine whether it is within the set frequency difference range; and the detection circuit 'detects the frequency of the speed feedback signal and the command signal and generates the two signals The amount of frequency error between. 1 The phase-locked speed control device as described in item 3 of the patent scope, wherein the detection circuit is constituted by a counter. 5 The phase-locked speed control device according to item 1 of the scope of the patent application, wherein the automatic phase correction circuit includes: an edge-triggered detection circuit that detects the rising edge of the speed feedback signal and the command signal Occurrence time; a phase detection circuit used to detect the relationship between the phase lead and backward of the speed feedback signal and the command signal; and a detection circuit 'which detects the speed feedback signal and the command signal The amount of phase error between. 6 'The phase-locked speed control device as described in item 5 of the scope of patent application, wherein the phase detection circuit is composed of a D-type flip-flop. 7. The phase-locked speed control device as described in item 5 of the scope of patent application, wherein the detection circuit is constituted by a digital counter to detect the command and amend 1 ^ 92109668. It is the same as the difference between the pulse width of the speed feedback signal and the phase error in this 8-frequency condition. According to the phase-locked speed control device described in the scope of application for patent application, the control signal can be generated by-pulse width: a sequencer, a switching signal, and then control the three-phase helmet brush straight k motor The armature voltage. …, 9 A two-phase brushless DC motor phase-locked speed control method, which is used to control the speed of the phase, brush, and DC motors, and use the return signal from the Hall sensor to estimate the motor speed for speed control The phase-locked control method includes the following steps: Decoding the feedback signal of the Hall sensing element into a pulse wave signal with a frequency three times the frequency of the feedback signal of the Hall sensing element; The wave signal is divided to generate a speed feedback signal; a command signal is received and the frequency error between the command signal and the speed feedback signal is corrected; based on the amount of the frequency error, it is determined whether to modify the command signal and the speed Phase error of the feedback signal; adding the frequency error to the phase error 1 to obtain a total error amount; and performing calculations based on the total error amount to generate a new control signal for controlling the speed of the motor. 10. The phase-locked speed control method according to item 9 of the scope of patent application, wherein the signal form of the speed feedback signal is a pulse wave signal, which detects the motor magnetic pole by the Hall sensing element Position, resulting in three phases M Page 14 12227¾ δ33 Shame number 92109668 The scope of patent application for the year + month day correction is a square wave signal with a difference of 120 degrees, and the speed feedback signal is obtained through the decoding and frequency division steps, and its frequency is two times the frequency of the electrical angle change of the motor. i. The phase-locked speed control method as described in item 9 of the scope of patent application, wherein the new control signal can be passed through a pulse width modulator and a sequencer, and the sequencer is based on the Hall sensing The three-phase signal fed back by the component generates f switching signals, and then controls the armature armature Liao Liuxiao of the three-phase brushless DC motor.