TW200531423A - A sensorless technique for switched reluctance motors and dc brushless motors - Google Patents

Abstract

This invention proposes a sensorless technique for switched reluctance motors and dc brushless motors. By using a phase-locked loop circuit, the estimated rotor position and speed signals can be obtained. The method uses index signals and sends the signals to a phase-locked loop circuit to obtain the estimated rotor position and replace the position sensor. First, by using the self-inductance of the switched reluctance motor and the back emf of the dc brushless motor, the required indices can be generated. Then, the indices can be used to produce multiple high frequency clock signals. Next, the clock signals are sent into a counter. The data of the counter is feedback as the estimated rotor position angle through interfacing device. After that, the rotor speed can be computed by using the difference operating process.

Description

200531423 Description of the invention: [Technical field to which the invention belongs] Motor drive system for angle _ element; especially suitable for "magnetoresistive motor and DC brushless motor rotation shaft angle / speed estimation device. [Previous technology] Turning surface H In this paper, the non-excitation phase of the switched reluctance motor induced electric dust is used to obtain, for example, the non-linear relationship between the angle and the angle of the rotating shaft. ^ ^ Tenth Republic of China Patent Gazette No. 340991 The piezo- = type reluctance motor shaft angle estimation device is a non-excited phase voltage adjacent to the exciting phase. After simple waveform processing, we get-only the panel output voltage. The table method estimates the angle of the shaft.

[Summary of the invention] X The technical problem to be solved by the present invention ... The switch-type reluctance motor and the control of the Qinda · must produce a fixed size and input timing, and achieve the commutation and the angle of the closed-axis shaft side components The rotation of the motor is measured by the angle two and the speed of the rotating shaft is measured. -General light-made rider, with _ installed in _ using Hall element to fit a "permanent magnet installed on the shaft. It is also possible to detect the angle of the rotating shaft by ^ ⑽der) or resolver (resdver). However, the main object of the present invention is to provide a drive control device for estimating the angle of a switch-type magnetic shaft. Among them, the switching magnetoresistance "2" slope is used to estimate the self-inductance, which is obtained from the change in the estimated self-inductance—some > the test position E 'and the __circuit circuit will transfer this job to the second measured value , The most secret -_ New York estimation of financial law is complete, said the estimation of the turn ^ m 200531423 On the other hand, the drive control device for the estimation of the shaft angle of the DC brushless motor is based on an unexcited opposite electromotive force estimate 'obtained_ These zero-crossing point position signals are then converted into an estimate of the shaft angle by using a phase-locked loop circuit, and the estimated shaft angle is fed back to the final outline and the development of a closed-loop drive system is completed. The technical means for solving the problem of the present invention: The technical means adopted by the present invention to solve the problem of the conventional technology is to replace the pulse wave signal output from the shaft-side element with a pulse wave output from the phase-locked loop circuit as an estimated Shaft angle signal provides accurate estimation of motor shaft angle / speed. In this method, the self-monetization of the switched reluctance motor and the back-EMF change relationship of the DC brushless motor are respectively used to take the m fixed position signal of -㈣, and then send this-position signal to the phase-locked loop circuit to double it. Frequency processing 'Finally, the pulse wave signal output from the phase-locked loop circuit is sent to a counter to count the pulse wave signal. The data of this count n is fed back from the interface device to the rotation pumping angle estimator, and the rotation shaft angle a is estimated. For the rotation shaft angle, see the rotation speed of the motor obtained through differential calculation. The specific method and control process of the present invention will be further described by the following examples and attached drawings. [Embodiment] Firstly, referring to Fig. 1, it is a block diagram of the closed-loop speed control drive system of the primary shaft-less primary measuring element of the present invention. The Hall effect current detector detects the three-phase current signal of the motor, and the voltage-side components take out the three-phase motor and depend on it. Hang current / M signal through analog / digital miscellaneous ugly duty, _ interface device meets Weihe, using the self-inductance estimator to estimate the self-inductance of the feedback current signal, or will return The back-EMF estimator was used to estimate the back-EMF of the brushless DC motor. For the two types of horses, the angle side method uses the positioner to obtain the position pulse wave ring fixed by the motor. This position signal is first sent to the phase-locked loop circuit for frequency multiplication, and then the pulse wave output by this phase-locked loop circuit The signal is Gu-counting pulse signal. The data of this counter is fed back from the interface I to the rotation axis angle and the rotation angle is estimated. The angle of the shaft is calculated through the difference calculation to get the motor miscellaneous. The set Wei command < is subtracted from the estimated rotation speed% to the rotation difference Δ%, and the current required by the motor is obtained through the speed control operation. 200531423 = ^ current The command r cooperates with the estimated angle & to calculate the current of each phase. The command cc controls the write. Γ feedbacks Γ electric two-phase current signal /; and (together with the current wave width modulation far f 1 conversion $ or frequency conversion 11 ′ Generate the required electric current and current to drive the horse '70%-a closed-loop motor drive system without a rotating shaft and a measuring element. The principle of self-inductive estimation of a switched reluctance motor is as follows. The self-inductance is measured, and the estimation method is τ. Three electric switching modes are provided by the second ilw and the power translation concept 11. These three voltage cuts can generate two different slopes of the exciting current. If two different currents are used, The slant ^ conversion $ can be divided into two different estimation modes: method A and method B. Method A, '1 cooperation mode 0 and mode 2 cooperation mode 0's excitation current slope to estimate the self-inductance; Law B uses mode 丨Direct estimation of self-inductance with the slope of the exciting current in mode 2 Consider a phase where the motor winding when the phase voltage can be expressed as: v = ^ + - (Z /) dt

= iR + L .......... Formula (1) di. dL — + / — dtάθβ where V is the phase voltage of the stator coil winding, · is the phase current of the stator coil winding, and is The resistance of the stator coil windings, β is the differential operator, 4th, _, the self-inductance of the zirconium windings 纥 is the angle of the rotor motor, and% is the angular speed of the rotor motor. According to the phase voltage of the switched reluctance motor, the slope of the field current of the motor can be deduced as: di dt T (v ~ iR ~ ωα dL 1θ; Formula (2) When using method A, the motor self-estimation estimation is as follows. Conversion When the converter is operated under method a, the phase voltage of the motor has three values: 4 and 0. When the converter is switched to mode 0, the motor's phase voltage v = 0, and the formula (2) is substituted to obtain the mode. State current slope: 200531423 di ~ dt

modeO

L {-ίΚ ~ ^ Φ Equation (3) Similarly, when the converter is switched to the mode 1 state, the phase voltage of the motor is V = 4 at this time, and substituted into the formula (2), the current slope of the mode 1 state is obtained. di It model

j (Vdc-iR dL 7θ ~ Equation (4) In fact, the instantaneous current and back-EMF in equations (3) and (4) are not exactly the same. However, when the switching period of the converter is short, its current and back-EMF The average value of is almost the same, so it can be sighed that its back electromotive force and resistance voltage drop are the same. At this time, the estimated value of the motor's self-inductance can be derived from formula (3) and (sentence): dc rdi model di dt

modeO ····· ...... Equation (5) The relationship between self-inductance is estimated from formula (5). It can be seen that the self-inductance of the motor is only related to the winding phase voltage and the current slope of state mode 1 and The current slope of the switching state mode G is related. In the same way, § the converter is switched to the mode 2 state, the phase winding voltage of the motor can obtain the current slope of the mode 2 state: also substitute AiU2), di dt mode 2 ......... Formula (6) From formulas (3) and (6), the self-inductance of the motor can also be derived as L--vdc rdi mode 2 dt

modeO… Eq. (7) In method B, the converter operates in both mode 1 and mode 2 ... A similar derivation theory as in method A, when the converter voltage state of the motor is zero. The instantaneous values of the stator current and the back electromotive force reached are not endless; I; for the same purpose, the period is very short. In formulas (4) and (6), the estimated value of self-inductance can be obtained: the same as the resistance voltage drop. This 8 200531423

-2V fdi < ~ r dt mod el di dt mode2

dc I rdi K ~ dt model di dt model Formula (8) ^ Λ = (5), (7) and the self-inductance estimation method of the formula, it can be seen that only a large amount of feedback exciting current is required ^ In conjunction with the power conversion switching state And the size of the DC cake, the stator self-inductance of the closed reluctance motor can be estimated. The principle of the zero-crossing point estimation of the DC brushless motor back-EMF is as follows: The driving method of the DC brushless motor is generally two-phase conduction and one phase cutoff, that is, only two at a time = ^ on. The trapezoidal wave back electromotive force of the power converter is as shown in Figure 3 and Figure 3, and the corresponding current relationship is shown in the fourth figure: circle, *, 120 degrees. The fourth figure shows the process of changing the polarity of the back-EMF. The coil of the excitation phase obtains the back-EMF of the stable and then estimates the angle of the non-rotating shaft. The principle of estimation is as follows: According to the basic principle of the switched reluctance motor, if When the motor rotates for one turn, the stator self-inductance of each phase will be considered as f ^, and the number of sub-seconds will be found from one rotation of the reluctance motor. The minimum value is t Switch from DC brushless 4 basic considerations

When the motor rotates Han Yi® Φ right / 疋, and the number of rotor poles is K, the whole horse:,: = The electromotive force will change periodically once, from the zero point detection of a back electromotive force of zero Signal = The present invention uses a pre-measured switched reluctance motor phase loop multiplier technology to fix this fixed position ^ 200531423 pulse wave signals. 'Using this pulse wave signal to construct the rotation shaft angle estimation of the present invention ^. The phase-locked loop is equipped with a _frequency divider, which uses this phase-locked loop to input the signal at the input end to the frequency of the frequency multiplier. The architecture is shown in Figure 5. It is said that the system includes circuits such as phase frequency detection, low-pass filter control oscillator, and so on. It ’s convenient for Ma and 4 ^ 1 °. Assume that, when <== 8, when the switch-type magnetoresistive circuit-· circle ', there are 3 fixed position signals with the minimum value of self-inductance, as shown in the sixth figure. 1/8 clear, there are 3 fixed brain inverses with zero anti-Wei potential ^ \ = 7 of the six maps. When the stable position signals are made by the horse, from the micro-pulse signal to the input terminal of the lock circuit, the three position pulse signals are positioned ^. Because the position pulse wave domain only represents the motor rotation, a few simple phase-locked loop circuits will apply the principle of phase-locked loop in this paper, as shown in the figure below. If the position pulse wave signal of the Mango ™ frequency, the frequency multiplier is, then the counter rides the value C. The high frequency pulse wave signal will be sent to the counter for counting. The angle and rotation axis estimation angle M will be fed back to the microcomputer and estimated. Motor shaft ^ = c_360 ° _ ............... ................................... Equation (9) Rotary shaft estimation: Bismuth is obtained by differential calculation of the motor. The estimated diversion is as follows: ων = —il .......................... ............... Formula (10) where 4 is the mechanically estimated angular difference of the shaft, 1 micro-electric -Cap sampling period. Frequency 4 =; Analysis shows that when the motor speed per minute ", the input of the phase-locked loop /: rv ............... ............................................ Formula (11 ) 200531423 According to formula (11), it can be known that the output frequency of the phase-locked loop is: Formula (12) λ. N mNr ω · ω2 = Nω {= -——- ^ ............. ..... According to the formulas (11) and (I2), g can be used to calculate the input range and output frequency range of the phase-locked loop, which can be used to adjust the resistance of the low-pass ferrule. The value of the sum of the capacitors allows the phase-locked loop system response to meet the set requirements, and finally obtains a high-resolution shaft angular position. Experimental results: The present invention is actually used for a switched reluctance motor drive m. Several experimental results are described below. It is the position pulse wave signal amount lake. The eleventh figure is the position pulse wave octave signal measurement chart. The twelfth figure is the relationship between the estimated shaft angle and the actual motor shaft angle. [Schematic description] The figure is a block diagram for estimating the rotation angle / speed of the switched reluctance motor and the DC brushless motor according to the present invention. Schematic diagram of bridge scale converter. The second diagram is the conventional DC brushless motor or converter. The fourth diagram is the back-EMF and current waveform diagram of the straight alpha brushless motor. The fifth diagram is The schematic diagram of the phase-locked circuit is familiar. Chapter ', Figure ^ _ Measured the minimum value of the stator self-inductance of the switched reluctance motor to obtain a fixed position 7 tigers. The seventh figure is the present invention _Zhenzhen La brushless motor back EMF zero Schematic diagram of obtaining a fixed number. The eighth diagram of the position letter is a schematic diagram of the position pulse wave signal of the present invention. The ninth diagram is a schematic diagram of the multiplication of the mixed pulse wave of the present invention. The tenth diagram is a measurement diagram of the position pulse wave signal of the present invention. Figure 11 is the measurement chart of the position pulse wave octave signal of the present invention. Figure 12 is the relationship between the angle of the turn and the actual motor shaft angle estimated by the invention.

Claims (1)

200531423 Scope of patent application: 1. Open. The method of estimating the shaft angle / speed of the closed reluctance motor is to replace the output pulse signal of the shaft pick-up component with the pulse wave a of the phase-locked loop circuit, and use it as an estimated shaft angle to reach the shaft angle. / Accurate estimation of speed. The only method is to estimate the low value of the switch-type magnetoresistance ", ..., and is, to obtain a series of fixed position signals, and then apply this position signal to the phase-locking: ¾ circuit for frequency multiplication, and finally lock The wave output by the phase loop circuit = input—counter counts the pulse wave signal.—the counter data is fed back by the interface device = in the device, the shaft angle M is estimated, and the shaft angle bismuth is obtained by differential calculation: 2. According to the data The method of estimating the shaft angle / speed of a brushed reluctance motor according to item 丨 of the patent scope is to estimate the motor self-inductance from the combination of three different current slopes. 3_ According to the towel, please outline _2 the method, which Three kinds of single electricity materials ㈣ = power conversion miscellaneous supply generated by three different voltage switching modes. It is difficult to read in the mode ^ state 'At this time the phase voltage of the motor v = 〇, the current slope of the mode 〇 state can be obtained, di dt mode 0 L (one i R-ωβ i dL, .......... (l) t, · is the stator and winding phase cake '4 shirt of the stator coil 〃, 〃 is the differential transport heterodyne W Is time, Z is the self-inductance of the stator coil winding, meaning the angular velocity of the rotor motor and the child motor. When the converter Switch to the mode i state, at this time the horse's phase is turned ^ again, and the current slope of the mode 1 state can be obtained: V 一 · 'di mod e \ 7t The mode 2 state can be obtained. When the converter is switched to the mode 2 state, the motor The phase-to-phase voltage v = — &amp;, the slope of the current of the state is: ^ di 7t mode2 ^ Recognize ~ ........... The method of item 2 or item 3, two different current slopes are paired, and the switching of the converter can be divided into two different estimation modes, method A and method b. 2005 200523 A A is combined with mode 1 and mode 0 and The self-inductance is estimated by the slope of the exciting current in mode 2 and mode 0; the self-inductance is directly estimated by the slope of the exciting current in mode 1 and mode 2. 5. • According to the method in item 4 of the scope of patent application, method 8 of the motor The self-inductance estimation principle is that when the switching period of the converter is short, the average values of its current and back-EMF are almost the same, so it can be assumed that its back-EMF and resistance voltage drop are the same. At this time, it can be expressed by (1) and (2) , The derived self-inductance estimate of the motor is: dc rdi model di_ dt modeO ⑷ From equations (1) and (3), The self-inductance of the motor can be deduced as follows: rdi, Jt mode 2 di dt modeO (5) 6 ·. According to the method in the fourth scope of the patent, the method B of the motor is based on the principle of self-inductance estimation for the switching of the converter. At that time, the stator current and back-EMF instantaneous values of Chengda Motor are not the same, but their average values are almost the same. It can be assumed that the mode! The back-EMF and resistance voltage drop of the switching state of Mode 2 are the same. At this time, (2 ) And (3), the estimated value of self-inductance can be obtained: Method, estimate the lowest value of self-inductance of the Huguan-type reluctance motor, and obtain a series of fixed position signals. ~ 8.: A kind of DC brushless motor speed / speed estimation method, similar to—pulse signal collected by phase-locked loop circuit replaced by—pulse signal output from the shaft detection element, as an estimated horse, angle / speed An accurate estimate. However, this method is to estimate the back-EMF zero-crossing 'acquisition-string_fixed-position signal of the straight-line signal, and then to this-position signal to the phase-locked loop circuit for frequency multiplication, and finally a phase-locked loop The circuit inputs the pulse wave signal into the counter and counts the pulse wave signal. The data of a counter is calculated from the boundary = rotation shaft angle estimator, and the rotation angle correction is performed. The rotation shaft angle 差分 is differentially transmitted to the speed of the motor. 13 200531423 9. According to the method for estimating the shaft angle / speed of the DC brushless motor in item 8 of the patent application scope, estimate the back-EMF zero crossing point of the DC brushless motor to obtain a series of fixed position signals. 10 · According to the method of item 7 and item 9 of the scope of the patent application, the one position signal is sent to a phase-locked loop circuit for Y-fold frequency processing. η. According to the method for estimating the rotation angle / speed of a switched reluctance motor and a DC brushless motor according to item 10 of the scope of the patent application, the # multiple-frequency pulse signal output by a phase-locked loop circuit is a pulse signal. Heart t I2 · According to the hat-specific method, count-㈣ in the shaft angle estimator. I put it back to η. According to the method of item u in the scope of patent application, where the angle of rotation axis is estimated as N mN The count value ⑽ calculates the motor shaft angle. The estimated shaft angle is as follows: ⑺ The estimated shaft shaft angle θ of the counter: The estimated rotation speed of the motor after differential calculation. Where m is the number of motor phases, &lt; the number of rotor poles or magnetic poles, the degree difference, and Γ is the interrupt sampling period of the microcomputer. ’The relationship is ⑻ Δn is the mechanical estimation angle of the shaft 14