CN1054690A - Vector analysing microcomputer control system of double-feedback motor - Google Patents

Abstract

The invention belongs to wire wound asynchronous motor AC-AC frequency conversion doubly-fed adjustable speed field.It can be sought best efficiency point certainly or three kinds of methods are done multiple combination because of the meritorious and idle component of main motor rotor current being controlled the high linearity of obtaining rotational speed regulation respectively and can being regulated as required power of electric motor factor or reactive power.It has the change procedure of related parameter with specific computing method with regulation, it have sinusoidal wave form and with the microcomputer signal through power amplifier triggering each silicon controlled device, it is all by the system of computer operation.Whether it is divided into＜plain edition because of needing to regulate at a high speed〉and＜high-speed type〉two types.

Description

Vector analysing microcomputer control system of double-feedback motor

The invention belongs to wire wound asynchronous motor AC-AC frequency conversion doubly-fed adjustable speed field.

AC-AC frequency conversion doubly-fed adjustable speed technology is not subjected to motor capacity restriction, can regulates power factor, can supersynchronous rotating speed operation, rotor current can form sine wave, little, the efficient advantages of higher of frequency inverter capacity.At the equipment that only needs near speed governing with leg speed such as blower fan, water pump, interchange milling train ... at the place, have than more superior technology, the economic index of all methods of other modern speed governing.

In the doubly-fed adjustable speed technology of AC-AC frequency conversion, yet exist and remain improvements, mainly inventing the people with the present invention is the inventor's, number of patent application be 86105697-3's " digital control type AC-AC frequency conversion microcomputer control system of double-feedback motor " just mainly be to establish for solving the nonlinear problem that this class technology medium speed regulates, also establish for replacing analog circuit with microcomputer technology.The present invention then is after adopting those some basic principles and method aspect two, with the real component I to rotor current _ZPWith idle component I _ZQThe two is controlled to be main developing respectively, wherein to I _ZPControl in order to obtain the high linearity of rotational speed regulation, to I _ZQControl then in order to obtain the freedom that power factor or reactive power are regulated; Obtain and move and obtain freedom quiet to the zone, that dynamic reactive compensates automatically automatically by best efficiency point.The place that on technology, needs, even can be with above-mentioned work as multiple combination.

Do not see domestic and international data, report along this way exploration.

Following merogenesis explanation relevant issues

One, handles the principle explanation of several technical issues

1, the control of shaft torque

The basic representation of shaft torque can be reduced to

Mz∝ I ^′ _ZCOSφ ^′ _Z（1）

This is could set up under the constant condition of utmost point magnetic flux, and formula (1) is also identical with the stressed principle in conductor energising back in the stabilizing magnetic field.The rotor current of doubly-fed motor removes and is subjected to rotor-side slip electromotive force SE ₂Influence also be subjected to the control of all adjustable frequency conversion electromotive force of amplitude, phase place outward.This is the following main contents that we analyze.

In formula (1), with I ¹ ₂, φ ^' _ZStill reduction comes to rotor-side, just becomes:

Mz∝I _ZCOSφ _Z＝Izp （2）

The influence that counts utmost point magnetic flux then becomes

Mz∝E ₂I _ZP（3）

2, rotor-side active current I _ZPReactive current I _ZQControl respectively and usage

The output of the speed regulator that proportional and integral controller is made takes advantage of a coefficient as I _ZPUse, then torque and speed regulator are output into direct ratio and have guaranteed high linearity.

Now from several ways explanation I _ZQThe control method:

A, to require the power factor of unit (contain main motor and frequency converter, down with) to stabilize to the meritorious and reactive power measured value that COS φ ɡ establishes unit this moment be P _fAnd Q _fEarlier COS φ ɡ is scaled t ɡ φ ɡ, then unit should produce reactive power

Qɡ＝P _ftɡφɡ （4）

The reactive power that main motor produces is 3I _ZQE _Z, the reactive current of order main motor this moment is I _ZQ, then the reactive current after regulating should be

I _ZQɡ＝（Qɡ-Qf）/3E _Z+I _ZQ（5）

Formula does not count I in (5) _ZChange from the reactive current of frequency converter during variation, the latter is little because of frequency inverter capacity, influence also for a short time, and regulates the back continuously several times and just can eliminate error, θ among the figure one after the adjusting ₃Will for

θ ₃＝tɡ ^-1I _ZQɡ/I _ZP（6）

B, require the reactive power of unit to stabilize to Q ɡ

Q ɡ in the formula (4) is a set-point, and this kind adjusting method can be from formula (4).

C, to require the unit gross efficiency be peak η m

In the unit from I _ZQThe adjusting internal loss that can influence mainly be copper loss, and total copper loss W _TFor:

W _T＝〔（I _o-I ^′ _ZQ） ²+I ^′ _ZP ²〕r ₁+（I ² _ZP+I ² _ZQ）r ₂（7）

Order

I ^' _ZP=K ₃I _ZPI ^' _ZQ=K ₃I _ZQAnd dWT/dI _ZQ=0 (8)

After the arrangement

I _ZQ＝K ₃Ior ₁/（K ² ₃r ₁+r ₂）＝K ₂I _o（9）

So make I _ZQOften remain K ₂I _oCan make unit operation in η m point, consider I _oItself also becomes with stator side voltage, should proofread and correct.

D, requirement are carried out quiet, dynamic compensation to regional reactive power content

Formula (5) if in Q _fChange, then compensation rate also changes, and has carried out quiet, dynamic compensation simultaneously naturally.

Problem is whether the compensation ability of unit can satisfy regional needs, to this, can requirement be taken advantage of to send in the formula (5) behind the adjustable coefficient with proportional controller again and go.

E, to the selection and the combination of above-mentioned the whole bag of tricks

(1) as technological requirement based on energy-conservation, then with η m point method.

(2) serve as that main then the employing specified COS φ ɡ or specified Q ɡ method as technological requirement to transfer COS φ or to transfer Q ɡ.

(3) more meaningfully, can also get up above-mentioned three kinds of combination of effects, for example: a, about Q with diverse ways _fControl, establish the zone average reactive power be Q _f, wherein the reactive power truth of a matter (the very not frequent minimum reactive power amount that occurs in the reactive power fluctuation) is Q ₂Then the dynamic reactive power amount is Q ₃=Q ₁-Q ₂, with the proportional controller of two adjustable ratio respectively with Q ₁, Q ₃Turn to Q ^' ₁, Q ^' ₃, with Q ^' ₁+ Q ^' ₃The Q that forms _fAs total feedback quantity.Then can handle regulated quantity quiet, dynamic reactive power respectively, and for example, can be with reactive power amount Q ₂Upper and lower at its mean value greater than specified amount △ Q ₂Part just as Q _fUse, promptly stipulate one and allow fluctuation range.B, this Qf be still delivering to [8] original computational process place for well, because of as deliver to Q ɡ place will be Q ɡ, Qf all in drastic change, be unfavorable for adjusting.The specific mode of c, original COS φ ɡ, Q ɡ and η m is still constant, so we just can do quietly as required, still can look after the benefit of one of three kinds of designation methods during dynamic passive compensation.Usually should be to operate to the master with selection η m, improving COS φ ɡ again be the compensatory zone reactive power, should be to consider that according to the lower limit of this requirement dynamic reactive power is the control area voltage fluctuation, △ Q ₂Should be to consider that by the upper limit of allowance this is the combination of another aspect.GPRS related parameter is arranged, it is easy handing over MICROCOMPUTER PROCESSING again, the target of combined treatment reactive power content, method all are flexible, various in a word, add the application of microcomputer technology, make that we are easier to reach multiple purpose.

3, frequency conversion electromotive force E ₃And to rotor electromotive force E ₂Electric angle θ ₂Calculating.

From the vector relations of figure one rotor-side, can get

$E_2\sqrt{{\left({\mathrm{sx}}_2\right)}^2+{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="901084530\_DRIMG2.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2}---\left(10\right)$

E＝I _ZE _Z（11）

θ ₅＝tɡ ^-1sx ₂/r ₂（12）

θ ₄＝θ ₃+θ ₅（13）

E ₃sinθ ₂＝Esinθ ₄（14）

E ₃cosθ ₂＝Ecosθ ₄-SE ₂（15）

E ₃＝Esinθ ₄/sinθ ₂（16）

θ ₂＝tɡ ^-1Esinθ ₄/（ECOSQ ₄-SE _Z） （17）

θ in the formula (17) ₂Be calculated value, the θ that will reach after promptly this time regulating ₂Value is hereinafter referred to as θ _{Z ɡ}

θ among the figure one ₂In the time of＜90 °, frequency converter runs on rectification state.As θ ₂＞90 ° promptly run on inverter mode.This moment, the relation of each vector changed figure two, wherein θ into ₃, θ ₄, θ ₅Relation constant, θ ₂＞90 ° then the denominator of formula (17) be negative, θ ₂Tangent value for negative, formula (15)～(17) three formulas are still set up.

When main motor runs on when supersynchronous, the rotor-side vector is as figure three, its SE _ZFor negative, its stator rotating magnetic field and the counter-rotating of the cut direction between the rotor winding are so E lags behind I _Z, θ ₅Be negative value, θ ₄=θ ₃-| θ ₅|, as θ ₄For negative, θ then ₂Also lag behind E _Z, consider these after, still set up formula (15)～(17).

When speed regulator is output as when negative, expression needs electrodynamic braking, but blower fan, water pump type load are not needed electrodynamic braking to accelerate moderating process and regain that kinetic energy, will make frequency inverter capacity strengthen, make in the long-time running loss to rise because prepare braking condition, and the way of replacement is to allow I _ZPBe 0, θ ₃Be 0, promptly motor power output not allows load torque force its reduction of speed, when must electrodynamic braking, extends down by the derivation mode of front, also can look for answer.

4, θ ₂Measurement and control

Figure four shows fixed, and the rotor winding is one by one to magnetic field in the punctual magnetic field half-wave and the relative position between winding, and phase angle difference is ∝, then E between order magnetic field this moment and winding ₁, E ₂All be directly proportional with sin ∝, thus the time two windings equal cutting magnetic fields under the same magnetic potential angle of same magnetic field sine wave, therefore the electric angle relation between the stator and rotor vector could be set up in omnidirectional's amount of this moment figure one, so following relational expression is arranged:

θU ₁t-θ ₁-180＝θE ₂t （18）

θE ₃t-θE _Zt＝θE ₃t-θu ₁t+θ ₁+180＝θ ₂（19）

θ ₂＝θE ₃t-θu ₁t+θ ₁+180 （20）

The θ of formula (20) ₂The θ that gets for measuring and calculating ₂Actual value, call θ in the following text _Zf

θ u in the formula (20) ₁T is the rotor U to recording on time one by one ₁Electric angle, U ₁The U of t for recording simultaneously ₁Transient voltage, and U ₁Effective value be

$U_1={\mathrm{<figure-callout\; id="1"\; label="U"\; filenames="901084530\_DRIMG2.png"\; state="\{\{state\}\}">U</figure-callout>}}_{1\mathrm{<figure-callout\; id="2"\; label="tj"\; filenames="901084530\_DRIMG2.png"\; state="\{\{state\}\}">tj</figure-callout>}}\sqrt{\sqrt{2}\sin {\mathrm{\&theta;}}_{\mathrm{ult}}}--\left[21\right]$

Also can get from figure one:

13＝I ₁Z ₁Z ₁＝Nx ₁ ²+r 2 ₁（22）

12＝I ₁Z ₁sin（φ-4） （23）

₂₃＝I ₁Z ₁COS（φ-4） （24）

θ ₁＝sin ^-112/U ₁（25）

E ₁＝U ₁cosθ ₁- 23＝E ₂/K ₃（26）

I in figure one ₁Be ahead of (E ₁) time, φ is for negative, with substitution formula (23)～(26) can get corresponding θ ₁And E ₁

△θ ₂＝θ _zɡ-θ _zf（27）

△ θ in the formula _ZPromptly require E ₃Sine wave and E ₂The regulated quantity of electricity difference between sine wave, the method for adjusting be calculate △ θ ₂The back is from representing E ₃Take out instantaneous value in the cyclic-digit code of electric angle , with △ θ ₂Addition is inserted total in the cyclic-digit code immediately.Principle is seen figure five, the E among the figure ₃Sine wave moves to the P point, and (electric angle is θ _P) time θ _PThe waveform height at place is immediately because of adding △ θ ₂And reduce to θ _P+ △ θ ₂The height at place, and wave band changes the E among the figure into ₃(+△ θ ₂), as subtract △ θ ₂Then become E ₃(△ θ ₂) the indication wave band.

5, calculating and the utilization of corresponding clock pulse amount Ms of rotational speed N f, frequency f 1, frequency ratio f/f1 revolutional slip s and the every degree electric angle of rotor slip electromotive force sE2 etc.

The present invention is at first at blower fan, water pump class lotus.This type load scarcely needs high sensitivity, and only need mostly in 0.8～1.1 synchronous speed, to move, once there is related parameter can meet the demands so only regulate, so just can when each aligning of rotor winding, sends a signal pulse M in 360 ° of electric angle measuring and calculating of the every rotation of rotor _N1, the power supply phase voltage is sent a signal pulse by negative to 0 of positive mistake at every turn simultaneously, and two quantity of aiming between the pulse of establishing with 1 megahertz clock step-by-step counting are n ₂, two mistake 0 interpulse quantity are n ₁, then:

n ₂（1-s ₁）＝n ₁，（1-s ₁）＝n ₁/n ₂，s ₁＝1-n ₁/n ₂（28）

Make n ^' _ZBe the value that is directly proportional with actual speed, then n ^' _Z=n ₂(1-s ₁) ²=n ² ₁/ n ₂, be scaled the actual speed n of the motor of p number of pole-pairs again _f(rev/min) then:

$\mathrm{nf}={\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="901084530\_DRIMG2.png"\; state="\{\{state\}\}">n</figure-callout>}}_2^{\&prime;}\&times;3000/20000p={\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="901084530\_DRIMG2.png"\; state="\{\{state\}\}">n</figure-callout>}}_2^{\&prime;}3/20p=\frac{3}{20p}\&CenterDot;\frac{{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="901084530\_DRIMG2.png"\; state="\{\{state\}\}">n</figure-callout>}}_1^2}{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="901084530\_DRIMG2.png"\; state="\{\{state\}\}">n</figure-callout>}}_2}$

Rotor slip electromotive force SE ₂The clock pulses number of per 1 ° of electric angle is:

Ms＝n ₁/360s ₁（30）

Above n in various ₁, s ₁Get by surveying, calculating, with its actual frequency f by name ₁, then under three and the specified power frequency f between due n, s etc. conversion relation be:

n ₁/ 360s ₁So=n/360s is n ₁/ n=s ₁/ s, s=s ₁N/n ₁(31)

First formula is to get according to the constant viewpoint of Ms before and after converting in the formula (31), and second formula is by the first formula conversion, and the 3rd formula is by the second formula conversion, is inversely proportional to because of the clock pulse amount in frequency and the cycle again:

n ₁/n＝f/f ₁（32）

N=2 * 10 in various ⁴(clock pulse frequency is 10 * 10 ⁵)

The S of formula (31) is in order to calculate the f/f of rotor reactance, formula (32) ₁In order to being scaled umber of pulse under the actual frequency corresponding to the clock pulses number of each controllable silicon trigger angle α, β under the specified power frequency.

6, sinusoidal wave formation

If one is the main cyclic-digit code generator that constitutes with the forward-backward counter,, then number can be represented E as period is decided to be 1-360 ₃The digital every conversion one all E of sinusoidal wave electric angle ₃A cycle also turns round, even count when clock pulse is every that cyclic code adds (subtracting) 1 Ms the time, subtraction during the supersynchronous computing of main frame, whenever after reducing to 1, subtract again and do add operation when 1 self-purchased number is the operation of 360 main frame metasynchronism, whenever adding 1 self-purchased number after being added to 360 again is 1, and cyclic-digit code itself is promptly represented an electric angle, with the SIN function of electric angle E on duty ₃Effective value take advantage of again

Be E ₃Instantaneous value E _3t, electric angle of unnecessary every change is promptly calculated once, the experience explanation, and 15 ° of calculations once also can period itself be got the high accuracy that every degree one change is to obtain angle value, and the precision Controlling Source is at △ θ ₂

7, the processing of rotating speed and current regulation loop

The front has been mentioned speed regulator and has been made of proportional and integral controller, its output and I _ZPBe directly proportional to obtain high linearity, make the integration time constant τ and the proportionality coefficient K of adjuster again _PFor adjustable, then can improve sensitivity and can suppress overshoot again.

As for current regulation loop, because electric current is I _ZP, I _ZQForm, the two all has specific target should not transfer again, and blower fan, water pump type load are not had the high request of sensitivity, does not also need to transfer, so cancelled electric current loop again.

8, about voltage compensation

Voltage compensation comprises: a, stator exciting curent I _oWill be with U ₁Non-linearly increase, subtract and preferably grasp its rule and obtain I with look-up table _oActual value, to go out actual value, b, E with approximate algorithm computation at least ₂Change, it is also not only with U ₁And become, also with μ ₁With E ₁Between angle and becoming, but its all total and E ₁Be directly proportional, so we calculate E ₁After take advantage of a coefficient with E ₂E ₂, be to calculate I more exactly ₂, E ₃Deng required, from E ₁The E that calculates ₂Will arrive next computing cycle just can use.

9, about directly triggering controllable silicon through power amplifier with the microcomputer signal.

Front [E ₁Sinusoidal wave formation] the described E that has solved a frequency conversion phase (a phase) of a joint _3taThe sinusoidal variations problem, now with E _3taBe scaled its due trigger angle α, β and be scaled the clock pulse amount M corresponding again with α, β ^' _C1～2(α, β itself represents a supply voltage by the time of bearing after just crossing at 0, and this time is measured with the clock pulse amount again, M ^' _C1Corresponding to α angle, M ^' _C2Should be in the β angle) same, α, β and the M of frequency conversion phase b, c ^' _C3～6Can be by the E of b phase ₃Tb hysteresis E ₃Ta120 ° of electric angle, E ₃Tc hysteresis E ₃Ta240 ° of electric angle calculated and got.On the other hand, establish three counter JA-C again three phase mains is lighted counting from negative to just crossing 0, this phase moment electric angle is all represented in the output of each counter, establish a comparator at each controllable silicon place again, more than two kinds of umber of pulses send into separately comparator respectively, when two kinds of umber of pulses equate, send this silicon controlled triggering signal, trigger controllable silicon through power amplifier, see accompanying drawing eight and explanation thereof for details.

10, to the measuring and calculating, regulating cycle requirement

All be to establish therefrom and can see above: the E that is converted into to regulating the very not high blower fan of rate request, water pump type load ₂Will arrive following one-period and just can use, the reactive power of frequency converter itself changes the following cycle that will arrive and just can compensate; These once just can not eliminated the effects of the act, and because of following one-period may also have new error to occur, in the time of secondly need doing dynamic reactive power compensation, or to band frequent impact load place, the general requirements response time is very short, takes following measure for this reason:

At the rotor winding one by one to sending pulse M on time _N1Also when whenever advancing 60 ° of electric angles (giving an example), sends rotor a P-pulse M outward, _N2, (contain M at per two adjacent pulses _N2Between and M _N1With M _N2Between) in 6 times of clock pulse amount be n in the scheme ₂The n of former scheme ₁The usage of the method that measures constant original [9] only makes the following changes: do not send Ms+ and Ms-pulse, but whenever send SE one time through 60 ° of electric angles ₂The electric angle of advancing is counted △ θ E ₃, deliver to [6], original [2]-[4] and [7]-[10] are at M _N1And M _N2One of all once work as M when arriving according to former scheme computing _N1[5] computing once during arrival.And with I ^' ₁₀, E ₂And θ _2fSend original each frame, when [5] computing, [6] obtain △ θ E ₃, θ _2f, θ _{2 ɡ}After make following formula and calculate:

θE3t+θ _2ɡ1+△θE ₃-θ _2f＝θ′ _E3t（33）

θ E3t takes from [1] at that time in the formula (33) cyclic-digit code, the pin number "/" among θ 2 ɡ 1 show the θ 2 ɡ signals that obtain for the first time after the new registration signal, obtain inserting immediately behind θ ' E3t in [1] interior cyclic-digit code

As any M _N2During arrival, does not work [5], and the computing of [6] is

θE3t+△θE3+θ2ɡn+1-θ2ɡn＝θ′E3t （34）

In the formula (34) θ 2 ɡ n+1-θ 2 ɡ n be after once θ 2 ɡ deduct previous θ 2 ɡ, the difference that is about to twice θ 2 ɡ counts among new θ ' E3t, new θ ' E3t still inserts in [1] interior cyclic-digit code.

The signal that operates to supersynchronous or inferior step state is sent by [9], during metasynchronism, and △ θ _E3For on the occasion of, in formula (33), (34), do add operation, work as θ ² _E3tInserted △ θ ' when supersynchronous after should therefrom subtracting 360 at＞360 o'clock again _E3For negative, subtraction in (33), (34) is as θ ' _E3tShould add 360 when negative inserts again.

The computing method of △ θ E3: stator field is to the rotation speed n of stator _o, the rotating speed of rotor winding (1-s) n _oStator field is to the rotating speed sn of rotor winding _oTriangular relational expression is:

n ₀＝（1-s）n ₀+sn ₀（35）

Being decided to be then to the anglec of rotation of stator the stator field in any time slot, formula (35) becomes

θ _o＝（1-S）θ _o+Sθ _o（36）

Top (1-s) θ of 60 ° of electric angle substitution formulas (36) of usefulness for example _oItem is △ θ then _E3Be S θ _oAnd

△θ _E3＝60×s/1-s （37）

S herein can use S ₁Generation, then 1-s ₁=n ₁/ n ₂, n wherein ₂=6n ₃, n ₃For with 60 ° of clock pulse amounts that electric angle is corresponding, take advantage of 6 to be with n ₃N when being scaled 360 ° of rotor rotations ₂After the arrangement.Formula (37) becomes

△θ _E3＝60×n ₁/（6n ₃-n ₁） （38）

This calculating can be changed to △ θ with Ms in figure nine tables [9] _E3, still obtaining by tabling look-up, formula (36) can be in order to converse any when one by one the electric angle of any point in paracycle being concerned that P-pulse is spaced apart 60 °, as S=0.2, then [9] △ θ E3 of at every turn sending is 15 °, and regulating cycle is 4.17ms, as s=-0.1 △ θ then _E3Be 5.45 °, regulating cycle is 3ms, and three indexs are arranged here: 1. △ θ _E3Should not be greater than 15 ° to satisfy E ₃The little requirement of sinusoidal wave distortion.2 regulate the accent phases is not more than 6.7ms, and can (three phase mains take turns commutation) time meet the demands with the interior 3 Microcomputer Calculation times of size that can change next trigger angle so that the average commutation of rectification.

With 60 ° of angles of rotor rotation is the cycle, means the per second scalable more than 240 times, should be able to satisfy band frequent impact load as the requirement of milling train.

With the blower fan that the front is narrated, the control system of water pump type load contrasts, and claims that now the former is that [plain edition] this section is described for [high-speed type]

Two, system controlled by computer theory diagram and major loop

Adapt with top described each situation; major loop tie lines such as figure six have been proposed; it is three-phase zero a formula inverse parallel reciprocal circuit; as be other main junctions; can do suitable adjustment; transplant and use; symbol is except that general person among the figure; ask for an interview [symbol description], the rotor-side outer meeting resistance is used for starting process, does filtering during half the winding energising of the centre tap reactor of each frequency conversion phase and uses; reactance value increases to 4 times during two mid-series; in order to limit circulation, detect the sense of current to block circulation with Hall element in the frequency conversion output circuit, detect size of current and use to do overcurrent protection.

Figure seven is the system controlled by computer theory diagram, wherein:

[1] is " cyclic-digit code generator ", its inside is mainly forward-backward counter, when getting period when being 1～360, the digital electric angle number of degrees of promptly representing the E3 sine wave, the Ms+ pulse that it is sent here by [9] makes it to do+1 computing, after adding to 360, coming the promptly self-purchased number of Ms+ pulse again is 1, as what send here be that Ms-then does-1 computing, comes Ms-then to purchase number by oneself again after reducing to 1 is 360.

[2] be " table of natural sines ", in order to look into the Sin θ value of θ.

[3] be " E _3tCalculator ", the E3 work that the Sin θ that it comes with [2] is next with [7]

E ₃Sin θ=E _3taCalculating, calculate E then _3tb, E _3tc; Calculate corresponding to E _3taThe trigger angle a of～c～c α (β); Calculate corresponding to the clock pulse M under a～c α (β) power frequency ^' _C1～6; Multiply by K α more respectively must be corresponding to the clock pulse amount M under the actual frequency _C1～6, because this a kind of computational process can calculate earlier and be stored in the table, so from obtaining E _3taRise until obtaining M ^' _C1～6The table (3) that all can do in the line chart nine is for future reference, common form " the E3 sinusoidal waveform apparatus for converting " in [1]～[3].

[4] see figure eight for " controllable silicon trigger equipment " its principle, wherein OA～c is that the voltage of three power supply phases is by the negative pulse signal that sends during to positive zero crossing, it makes the counter JA～c clear 0 of its back, the restatement number, so counting Mya～c of JA～c represents its electric angle respectively, their electric angle amount is delivered to three corresponding comparators of frequency converter of a～c again respectively, Mc1～6 are just being represented three frequency conversion phases respectively, the clock pulse amount of negative group silicon controlled trigger angle α (β), when two kinds of pulsed quantities that enter each comparator equate, promptly send the silicon controlled triggering signal of this comparator correspondence, trigger controllable silicon through power amplifier.

[5] be " E2, θ _2fCalculation element ", it has following column count content: 1. by the U that surveys _1t, θ U _1tDeng calculating: U ₁=U _1t/

Sin θ _U1t, I ₀=K ₁U ₁ =I ₀K ₂This batch total is calculated and can be replaced with the table [5] 1 of looking into figure nine.2, by I ₀, I ^' _ZP([10] are come), I ^' _ZQ([8] come), etc. calculating: I _1Q=I ₀-I ^' _ZQ, I _1P=I ^' _ZP $I=\sqrt{I_{\mathrm{IQ}}^2+I_{\mathrm{LP}}^2}$ , φ=tg ^-1I _1Q/ I _1P12=I ₁Z ₁Sin(φ-4), 23=I ₁Z ₁Cos(φ-4) this batch total is calculated and is being obtained I _1QAfter can be with the table of looking into figure nine (5) ₂Replace.3, by U ₁, 12 calculate: θ ₁=sin ^-112/U ₁, U ₁Cos θ ₁, this batch total is calculated can be by the table (5) of figure nine ₃Replace.4, by 23, U ₁Cos θ ₁Calculate E ₁=U ₁COS θ ₁-23,

=K ₃E ₁5, by θ U ₁T, θ _E3t([1] is come) calculated:

=θ _E3t-θ _U1t+ θ ₁+ 180(5) output signal has (below be added with etc.): I ^' ₁₀(to [8]), θ 2f(is to [6]), E ₂(to [7] and [8]).

[6] be θ 2 adjusting devices

, it is with θ _{2 ɡ}([7] are come), θ 2f([5] come), θ _E3tCalculating such as ([1] are come):

=θ _E3t+ θ _{2 ɡ}-θ _2f, its output θ ^' _E3tSend [1].

Right

High-speed type , [6] have two kinds of computing methods: the θ that it is obtained ₂Signal is θ _{2 ɡ 1}The time, use θ _E3t([1] is come), θ _{2 ɡ 1}([7] are come, △ θ _E3([9] are come), θ _2f([5] are come) calculated: θ _E3t+ θ _{2 ɡ 1}+ △ θ _E3-θ _2f=θ ^' _E3tOutput θ ^' _E3t(to [1]), it obtains signal is θ _{2 ɡ}, use θ E at 2～6 o'clock ₃T([1] come), θ _{2 ɡ n+1}, θ _{2 ɡ n}(all from [7]), △ θ _E3([9] are come) calculated: θ _E3t+ θ _{2 ɡ n+1}+ △ θ _E3-θ _{2 ɡ n}=θ ^' _E3tOutput θ E ^' _3t(to [1]).

[7] be " E3, θ 2 ɡ calculation elements ", it has following column count content: 1, by S([9] come) calculate: $E_2=\sqrt{{\left({\mathrm{sx}}_2\right)}^2+r_2^2}$ 、θ ₅＝tɡ ^-1sx ₂/r ₂。This batch total is calculated and can be replaced by table among the figure nine [7] 1.2, by Z ₂, I ₂(being come by [8]) calculates E=I ₂Z ₂3, by θ ₅, θ ₃([8] come) calculate θ 4=θ 3+ θ 5, and look into function table and get sin θ ₄And cos θ ₄4, by E.sin θ ₄Cos θ 4 calculates ESin θ 4ECos θ 4 these batch totals and calculates and can replace 5, be come by [9] by S(by looking into figure nine tables [7] 2), E2([5] come) calculate SE ₂6, by SE ₂, Esin θ ₄.Ecos θ ₄Calculate:

=tg ^-1(Esin θ ₄)/(Ecos θ ₄-S _E2), E ₃=Esin θ ₄/ sin θ _{2 ɡ}So this batch total is calculated owing to there has been ESin θ 4 just can get ECos θ 4, has had θ 2 ɡ that Sin θ 2 ɡ are just arranged can be by looking into (7) 3 replacements of figure nine tables, and the output of [7] has E3(to [3]), θ _{2 ɡ}(to [6]).

[8] be " I _2QControl device " it has 4 simulation signal generators: 1, the reactive power feedback quantity Q of unit _fBecome digital quantity through analog to digital conversion.2, the active power feedback quantity P of unit _fAlso become digital quantity.3, the powerfactorcos ɡ of appointment also becomes digital quantity after being changed to t ɡ φ ɡ, and 4, the reactive power Q of appointment _{ɡ Z}Be changed to digital quantity, control method: a: by P by specifying cos φ ɡ operation to calculate content _f, t ɡ φ ɡ calculates θ _{ɡ 1}=P _fT ɡ θ ɡ is by θ _{ɡ 1}, θ _f, E ₂([5] are come), I _ZQ(depositing) [annotated and whenever calculated I one time _ZQAfter all deposit a memory ready in, number add [depositing] word table from the numeral of wherein taking out with pin and show, insert in the memory with former poke of generation with it again after calculating next time], calculate (Q _{ɡ 1}-Q _f)/3E ₂+ I _ZQ(depositing)=I _ZQ, =K ₃I _ZQBy I _ZP([10] are come), I _ZQCalculate I ₂=√ I ² _ZP+ I ² _ZQ, θ ₃=t ɡ ^-1I _ZQ/ I _ZPThis two formula can replace output signal, I with figure nine tables (8) ^' _ZQ(to [5]), I ₂, θ ₃(to [7]).

B, by specifying θ _{ɡ 2}Content is calculated in operation: compare cancellation θ with top a bar _{ɡ 1}Calculating, in the calculating afterwards with θ _{ɡ 2}For Q _{ɡ 1}C, press the computing method content of best efficiency point operation: by I ^' ₁₀([5] are come, and it is I _ZQDesignated value), I _ZP([10] are come) calculates I ₂θ ₃Process and two of a, b with, output signal I ^' _ZQ(to [5]), θ ₃.I ₂(to [7]).

[9] be " parameter calculation apparatus " its calculating content: by the n that measures ₁, n ₂Calculate

, output signal Ms ± (pulse signal) (to [1]), s(to ([7]), Nf(to [10]), Kd(is to [4])

" high-speed type " do not included Ms, and M does not bother to see me out ^{+ S} _-SSignal, but calculate △ θ _E3=60 (n ₁)/(6n ₃-n ₁) send [6].

[10] be " proportional and integral controller " its calculating content: △ N=N ɡ-Nf

U _SC=Kp △ N+ (KP)/(τ) △ Ndt, I _2P=K ₄U _SC, I ^' _2P=I _1PSignal output I _2P(to [8]), I ^' _2P(to [5])

Three, applicating and exploitation

The frequency changer circuit frequency-changing speed-regulating technology of doubly-fed motor to only needing near the load of speed governing synchronous speed, has than the obvious superior technical-economic index of all methods of other modern speed governing.The objective of the invention is on its existing level, to improve again as much as possible.

The present invention has three main targets: 1, be directly proportional with the rotor current real component with the output of speed regulator and obtain the high linearity of rotational speed regulation.2, by technology to the difference requirement of reactive power Changing Pattern and control the idle component of rotor current independently.3, control system all adopts microcomputer technology.It is also never to attempt for the people in (just known to the inventor) existing this class speed regulation method that the three integrates many in all benefits that can bring into play.

The present invention also is in the conceptual level, but has prepared necessary condition, can launch further work, microcomputer technology itself, and we have also done some parallel work, think to develop.

This paper only stresses and the patent application related content, and the corresponding problem of routine techniques then conforms to the principle of simplicity, from economizing.

The wire wound asynchronous motor still uses in a lot of places, the almost completely blower fan that captures for the cage type motor, water pump type load, consider speed governing to need and use the wire wound motor instead to adopt the doubly-fed adjustable speed method more also be favourable, especially it serves as right accounting for the big part of factory (workshop) internal loading proportion with the buncher capacity, cause can be so as to making quiet, the dynamic passive compensation in the factory (workshop), and the running status of buncher self all improves and saves energy.And cost does not rise.

Four symbol descriptions

AA+～cC-＜controllable silicon trigger equipment〉in＜comparator numbering.A, b, c be frequency conversion mutually number, A, B, C are power phase ,+,-, positive and negative group of controllable silicon.

A α (β)～c α (β)-a, b, c be frequency conversion mutually number, α (β) is phase shifting angle (inversion angle)

The power factor E of Cos φ .-given (requirement) ₁-stator-induced electromagnetic gesture

E ₂-rotor open phase electromotive force E ₁-frequency conversion electromotive force effective value

-rotor induction gesture rated value E-rotor loop SE ₂With E ₃Synthetic

-frequency conversion electromotive force instantaneous value, the pin electromotive force

A～c shows three frequency conversion phase f-power frequencies

f ₁The actual frequency I of-system ₀-stator A phase exciting current

-stator A phase rated exciting current I ₁-stator A phase current

I _1P-I ₁Real component I ₁₀-I ₁Idle component

I _2P-I ₂Real component I _2Q-I ₂Idle component

I ¹ ₂-reduction is to the I of stator side ₂I ¹ _2P-I ¹ ₂Real component

I ¹ _2Q-I ¹ ₂Idle component JA, JB, JC-counter (see figure

k ₁-k ₁=I / U ₁₀Eight and the explanation)

k ₂-k ₂=

r ₁/ k ² ₃r ₁+ r ₂k ₃-with I ₂Reduction is returned to stator side

k ₄-I _2PCalculate coefficient with the pi regulator output valve

Ratio K _PThe proportionality coefficient of-pi regulator

-=f/f ₁M _01～6-send to and trigger six groups of SCR

-stator winding is the clock pulse amount to sending on time one by one

Signal pulse M _N2The pulse of-rotor-position signal

M ₂-SE ₂The clock of per 1 ° of electric angle correspondence

-A～C three phase mains is by negative

Pulsed quantity to just cross 0 light with the time

The impulse clock pulsed quantity counting representative that send to [1]-S＞0 o'clock [9]

The electric angle of signal

M _3-The pulse M that send to [1]-S＜0 o'clock [9] _Z-shaft torque

Signal N ɡ-rotational speed setup

I ₂One in the pairing electrical network of-rotor current n-power frequency

The clock pulse amount of cycle

n ₁-power supply A phase voltage every adjacent twice by negative to n ₂-every adjacent twice stator and rotor

Between clock pulse amount winding between the positive zero crossing is being aimed at one by one the time

n ¹ ₂-be with n ₂Turning to actual speed becomes positive clock amount (to change with reality

The rapid-result inverse ratio of value behind the ratio)

-＜high-speed type〉N in the burst length of adjacent position _f-with n ¹ ₂It is extremely right for P to change calculation

Clock pulse amount number under rotating speed (rev/min)

The input active power P of-unit actual measurement ₂The shaft power of-main motor

The reactive power of-given (requirement)

-by specifying Cos φ ɡ method to calculate

-by appointment

The θ ɡ amount of the θ ɡ amount that directly obtains

The input reactive power Υ of-unit actual measurement ₁-stator loop resistance

Υ ₂The resistance S of-rotor loop (containing frequency converter) ₁-with n ₁Revolutional slip for benchmark

S-S ₁The time of integration of the revolutional slip τ-pi regulator of reduction to the power frequency is normal

U ₁The effective value number of-power supply A phase voltage

U _IeThe specified effective value U of-power supply A phase voltage _It-aligning samples constantly one by one

W ₁The U of total copper loss of-unit ₁Instantaneous value

X ₁The reactance X in-stator loop ₂-rotor loop (containing frequency converter)

Z ₁Impedance=the reactance in-stator loop

X ² ₁+ r ² ₁Be constant Z ₂-rotor loop (containing frequency converter)

η _mThe peak efficiency impedance=(sx of-unit operation ₂) ²+ r ² ₂

θ ₁-U ₁With-E ₁Angle theta ₂-E ₁With E ₂Angle

θ ₄-E and E ₂Angle theta ₅-E and I ₂Angle

-θ ₂Required value -θ ₂Actual value

θ _Ult-aligning samples φ-I constantly one by one ₁With-E ₁Angle

U ₁Moment electric angle ψ-I ₁r ₁With I ₁Z ₁Angle

ZB-rectifier transformer JD-alternating current motor

-starting resistance θ _ES-the period of taking out from [1]

θ ¹ _E3T-θ _E3T in [6] with △ θ ₂Code value

Value M after the addition _C1～6Triggering under the-practical frequency

M ¹ _C1-8The clock pulse amount at the clock angle of the trigger angle the under-power frequency

Pulsed quantity △ θ ₂-θ ₂Regulated quantity=

△ θ _E3SE when-rotor advances 60 ° of electric angles ₂Before

The electric angle of advancing

Claims (3)

1, a kind of vector analysing microcomputer control system of double-feedback motor, it special little at what:

(1) it has a speed regulator that makes with proportional and integral controller, and the coefficient motor rotor electric current I of deciding is taken advantage of in the output of speed regulator ₂Real component I _2p＜I _2pControl device 〉;

(2) it has one independently to control main motor rotor current I by technological requirement ₂Idle component I _2Q＜I _2QControl device 〉;

(3) it has one to use I _2p, I _2QRotor slip electromotive force SE ₂Go out frequency conversion electromotive force E etc. calculation of parameter ₁And and E ₂Between electric angle θ ₂Desired value θ ₂＜E ₃,

Calculation element 〉;

(4) it has one to constitute with cyclic-digit code, sinusoidal function memory, multiplier, data storage etc., draws three frequency conversions with clock pulse amount M _C1-6The representative respectively organize controllable silicon trigger angle α, signal beta＜E ₁Sinusoidal waveform apparatus for converting 〉;

(5) it has one to use M _C1-6With three power supplys mutually with the clock pulse scale show its electric angle variable signal＜the controllable silicon trigger equipment;

(6) it has a steel I _2p, I _2Q, stator excitation power supply I _o, a pair of stator that records on time of stator and rotor winding specifies the voltage u of phase ₁T, electric angle θ ₀₁T, E ₁Electric angle θ _E3T etc. are to calculate θ ₂Actual value θ _2fAnd E ₂＜θ _2f, E ₂Calculation element 〉;

(7) it has one to use θ _2o, θ _2fThe θ that calculates ₂Regulated quantity △ θ ₂, and with it＜add go into to represent E ₃The cyclic-digit code instant value θ of the sinusoidal wave electric angle of voltage _E3Among the t and finish adjustment process＜θ ₂Adjusting device 〉;

(8) it has a mensuration, calculates speed feedback N _f, revolutional slip S, SE ₂The clock pulse amount M of every degree electric angle correspondence ₃, power frequency f and practical frequency f1 ratio k a=(f/f ₁) wait＜parameter calculation apparatus 〉;

(9) it is finished internal calculation, the external relation of above-mentioned each device and unifies operation process with microcomputer technology and forms＜Control System of Microcomputer 〉, this system, do not require that at the overwhelming majority quick, high-precision blower fan, pump type load can be one＜plain editions〉system, and at being with impact load or the load that regional dynamic reactive is compensated requirement being arranged, also can be one＜high-speed type system.

2, a kind of vector analysing microcomputer control system of double-feedback motor according to claim 1, it special little at what:

(1) described＜I _2PControl device〉in the integration time constant τ of proportional and integral controller and proportionality coefficient kp all can change with △ N, under defined terms, change automatically;

(2) described＜I _2QControl device〉be by the power factor (PF) Cos φ ɡ of technological requirement or reactive power Q ɡ operation or requirements operation what best efficiency point, even by the myriad combinations mode operation of three kinds of requirements etc. and through corresponding calculated, control procedure realization;

(3) described＜high-speed type〉system is by increasing rotor position determination, changing and follow digital formation and θ ₂Measures such as angle control method, shortening calculating and regulating cycle form.

3, according to claim 1,2 described a kind of vector analysing microcomputer control system of double-feedback motor, it special little: its both available what three-phase zero formula attitude stream inverse parallel main junction system, also portable what three-phase bridge main junction system at what.

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