CN2532614Y - Sound frequency switch type ac inductive motor - Google Patents

Abstract

Disclosed is a switch AC inductive motor. The stator and the rotor iron core of the utility model are made of soft magnetic material punched sheet with corresponding frequency characteristics or ferrite materials; the rotor has a rat cage structure; a stator magnetic pole adopts the switch exciting technology with an exciting voltage of pulse width voltage within the range of audio frequency and ultra-audio frequency or of a range modulating voltage. Under the condition of the same output power, the volume and weight of the motor can be reduced by a plurality of times to a dozen of times. Besides, the utility model has low cost and can realize continuous stepless speed regulation from thousands times of rotating per minute to zero speed while maintaining good mechanical performance.

Description

Audio Switch type AC induction motor

Technical field

The utility model relates to a kind of novel motor, more precisely a kind of Switch type AC induction motor in audio frequency and superaudio scope.

Background technology

Existing induction alternating current (AC) motor mainly is a squirrel-cage alternating current asynchronous inductor motor, for the brush DC motor is arranged, have simple in structure, cost is low and output torque bigger advantage.This motor adopts usually has the two-phase of 90 ° of phase differences, or the continuous sine voltage of the three-phase with 120 ° of phase differences is excitatory, produce continuous sinusoidal wave rotating magnetic field in the air-gap between stator and rotor, thereby make the cage rotor rotation, its rotating speed can be calculated by following formula: n=60*f1/p, wherein p is the magnetic pole logarithm of motor stator, and f1 is excitatory ac frequency.As seen, after the structure of motor was determined, mainly by frequency f 1 decision, the effective way of therefore controlling its rotating speed was to change excitatory ac frequency f1 to its rotating speed.For example, establish motor magnetic pole logarithm p=2, when excitatory ac frequency f1=50 hertz, its per minute rotation speed n=1500r/min; When the f1=40 hertz, its rotation speed n=1200r/min, or the like.For this reason; people have created frequency control; the method of various control speed such as vector control speed governing; but because the operating rate of actual needs is general all far below the running speed of motor; and owing to reasons such as the impedance operator of the field winding of motor and torque requests; on the low side as the torque of AC asynchronous motor when the low cruise; often can not obtain lower rotating speed by the excitatory ac frequency f1 of unrestricted reduction; therefore; usually also need to adopt simultaneously gear graduation as mechanical system etc.; to satisfy various needs in actual use; so; increased the volume of use cost and equipment undoubtedly again; weight, and its effect and unsatisfactory.

Over nearly two, 30 years, people's invention has also been used widely such as brushless, permanently excited direct current motor, stepping motor and switched reluctance motor etc., can be referred to as electronic motor or electric motor, its operation logic mostly is alternately to utilize the attraction that produces between the opposite pole by control technology, makes the rotor rotation.Though this type of motor has tangible improvement at aspects such as speed governing, size and weight, aspects such as its manufacturing cost, speed adjustable range, output torque still can not satisfy the more high performance requirement that increases day by day.

Summary of the invention

Technical problem to be solved in the utility model is:

One is that this kind novel motor should have bigger power density, and under the condition of equal power output, this kind motor is than existing motor in other words, and its volume and weight can reduce several times to tens times.

They are two years old, be that this kind novel motor has bigger speed adjustable range than existing motor, its output speed can be adjustable to continuous stepless between zero rotating speed in the rated speed of the thousands of commentaries on classics of per minute, cheaper manufacturing cost, add very little size, weight, and can under the situation of permanent torque, realize the gearless speed change.

The utility model solves the problems of the technologies described above the technical scheme that is adopted:

This kind motor is to adopt switching frequency to realize at the alternating electromagnetic induction technology of audio frequency and superaudio scope, therefore, can be described as audio frequency and superaudio Switch type AC induction motor.This kind motor, by support, stator and rotor are formed, stator core is the garden tubular, its inner surface has the stator tooth by the angle same distribution that radially inwardly stretches, it between tooth and tooth the stator slot that connects vertically, field winding is put in the stator slot, and the quantity Z of its stator slot or tooth is determined by following formula: Z=2*M*P*Q, and wherein, M is the number of phases of excitation voltage, P is the logarithm of magnetic pole of the stator, Q is the quantity of the groove or the tooth of every extremely every phase, and motor rotor adopts cage-shaped structure, and the quantity K of the parallel electrically conductive bar in the metal inductor of rotor upper cage structure should equal 2 times of magnetic pole of the stator logarithm P, be K=2P, and be spacedly distributed along rotor outer surface.The excitation mode of stator field winding, adopt the excitatory technology of switch AC pulsed, excitation voltage is that its effective value and frequency equate, and have the two-phase of 90 ° of phase differences, or have the continuous sine voltage of three-phase of 120 ° of phase differences, can be described as modulated sinusoid voltage, pulse square wave voltage with audio frequency or superaudio scope, can be described as modulated square wave voltage, make the pulse modulation voltage after pulse width modulation or the pulse amplitude modulation, can be described as sinusoidal wave pulse modulation excitation voltage.The version of stator field winding when Q=1, adopts the centralized winding of 1/M pole span or whole pole span, and distributed winding is adopted in Q＞1 o'clock.The iron core of stator and rotor, should and do to be overrided to form vertically after the surperficial insulation processing by the soft magnetic material punching of the corresponding frequencies characteristic that satisfies audio frequency and superaudio scope, also can make by the mode of whole or segmentation vertically by the Ferrite Material with corresponding frequencies characteristic etc.

The related the most essential innovation of novel motor of the utility model be excitatory technology innovation, promptly adopt at the sinusoidal wave pulse modulation voltage of audio frequency or superaudio scope excitatory, after the field winding in the stator is energized, produce needed pulsation alternation formula rotating magnetic field in the air-gap between stator and rotor, in epitrochanterian bus, produce induced current, and be subjected to the effect of the electromagnetic torque of this pulsation alternation formula rotating magnetic field, make the rotor rotation of motor.If the frequency of modulated sinusoid voltage is F1, the frequency of modulated square wave voltage is F2, in the operation process of motor, the rotary speed of pulsation alternation formula rotating magnetic field only is decided by the frequency F1 of modulated sinusoid voltage, and irrelevant, thereby just can realize the speed governing of motor by the frequency F1 that control circuit changes modulated sinusoid voltage with the frequency F2 of modulated square wave voltage.Because the pulse frequency of sinusoidal wave pulse modulation excitation voltage, promptly the pulsation alternative frequency of rotating magnetic field equals the frequency F2 that its value is in the modulated square wave voltage of audio frequency or superaudio scope, much larger than the frequency F1 of modulated sinusoid voltage.By the basic principle of electromagnetic theory as can be known, the impedance of motor field winding is directly proportional with frequency F2, and irrelevant with the frequency F1 of modulated sinusoid voltage, F2 exceedes height, and the volume of motor stator and rotor core and winding, weight just exceed little.As long as the relative fixed of holding frequency F2, even when making F1 near zero frequency in order to obtain extremely low rotating speed, also can guarantee the stable of motor output torque, thereby can be under the condition of good mechanical properties, the rated speed that is implemented in the thousands of commentaries on classics of per minute is adjustable to continuous stepless between zero rotating speed.Because motor size reduces, consumptive material also can be saved in a large number, and its stator and rotor core can adopt cheap soft magnetic material, so can reduce cost of manufacture greatly.

Description of drawings

Fig. 1 is the stator of 4 pairs of utmost point two-phase motors of 16 grooves and the transverse cross-sectional view of rotor.

Fig. 2 is the 1/2 pole span field winding in the motor shown in Figure 1 and the connection diagram of excitation voltage.

Fig. 3 is the centralized field winding expanded view of 1/2 pole span in the motor shown in Figure 2.

Fig. 4 is a motor sinusoidal wave pulse modulation excitation voltage waveform schematic diagram shown in Figure 1.

Fig. 5 A, 5B are pulsating rotating magnetic field and the rotor operation schematic diagrames that excitation voltage shown in Figure 4 produces.

Fig. 6 A～8B is the centralized field winding expanded view of several whole distance in the motor shown in Figure 1.

Fig. 9 is the transverse cross-sectional view of 24 groove 4 pairs of utmost point threephase motors stators and rotor.

Figure 10 is the centralized field winding expanded view of 1/3 pole span in the motor shown in Figure 9.

Figure 11 is a motor sinusoidal wave pulse modulation excitation voltage waveform schematic diagram shown in Figure 9.

Figure 12, the 13rd, pulsating rotating magnetic field and rotor operation schematic diagram that excitation voltage shown in Figure 11 produces.

Figure 14 A～16B is several centralized field winding expanded view of motor shown in Figure 9.

Figure 17, the 18th, the excitation control circuit block diagram of motor shown in Figure 9.

Embodiment

Figure 1 shows that the transverse cross-sectional view of 16 groove 4 pairs of utmost point two-phase motors stators and rotor, among the figure, " 010 " is the stator core of hollow garden tubular, " 101 " are the stator slot that connects vertically, " 102 " are stator yoke, " 103 " are the stator tooth by the angle same distribution that radially inwardly stretches, stator slot and stator ring gear stator inner surface are alternately, " 020 " is for there being the rotor of garden cylinder surface, the bus that is parallel to each other that " 104 " are spacedly distributed for the garden cylinder surface along the motor rotor iron core, bus and the conducting ring (figure does not draw) that is arranged on two end faces of Cylinder are fused into the metal inductor that is similar to cage-shaped structure, " 105 " are rotor core, " 106 " are armature spindle, " 107 " are the air-gap between rotor and the stator, and armature spindle is supported by the rotor bearing (figure does not draw) that is arranged on the support that fuses with stator core.At the quantity Z one of stator slot or tooth regularly, if the stator slot or the number of teeth Q=1 of every extremely every phase, can increase the bus number in magnetic pole logarithm and the corresponding rotor thereof, to obtain bigger output torque.In the embodiment shown in fig. 1, because the number of phases M=2 of excitation voltage, the quantity Z=16 of stator slot [101] or tooth [103], when Q=1, magnetic pole logarithm P=Z/ (2*M*Q)=4 has 8 buss in the rotor, is 2 times of magnetic pole logarithm.

As previously mentioned, to the related excitation voltage of the utility model is by the two-phase modulated sinusoid voltage with 90 ° of phase differences, or have a three-phase modulations sine voltage of 120 ° of phase differences, carry out the pulse excitation voltage that pulse width modulation or amplitude modulation(PAM) produce with modulated square wave voltage in audio frequency or superaudio scope.Can be called A phase, B phase and C modulated sinusoid voltage mutually for modulated sinusoid voltage.For convenience of description, can claim to be A phase excitation voltage by the excitation voltage of A phase modulated sinusoid voltage pulse modulated generation; The excitation voltage that is produced by B phase modulated sinusoid voltage pulse modulated is for B phase excitation voltage etc.Shown in Figure 4, Ur is a modulated square wave voltage, and its waveform is the symmetrical square wave that 50% occupation efficiency is arranged.Uas is an A phase modulated sinusoid voltage, and Ubs is a B phase modulated sinusoid voltage, and 90 ° of angles of the leading Ubs of Uas.Uwa, Uwb are respectively A, B phase width modulated excitation voltage, and Uma, Umb are respectively A, B phase amplitude modulation(PAM) excitation voltage.Just as known, for the excitation voltage of pulse width modulation, the pulse amplitude of this excitation voltage is fixed, its pulse duration with constantly the amplitude sampling value of modulation sine voltage is directly proportional in that each of modulated square wave voltage is corresponding.Among the figure, the back edge of each pulse in the excitation voltage of pulse width modulation is fixed on the rising edge or the trailing edge of modulated square wave voltage, and its forward position is variable, helps improving the efficient of motor like this, reduces noise; For the excitation voltage of pulse amplitude modulation, its pulse duration is fixed, pulse amplitude with constantly the amplitude sampling value of modulation sine voltage is directly proportional in that each of modulated square wave voltage is corresponding.As seen from the figure, be for the polarity orientation principle of the pulse amplitude of the excitation voltage of pulse width modulation or pulse amplitude modulation: when the amplitude of its modulated sinusoid voltage and modulated square wave voltage in the same way when (just promptly be all or be all negative), get on the occasion of, be positive pulse; When the amplitude of its modulated sinusoid voltage and modulated square wave voltage incorgruous (promptly one for just, one for negative) time, get negative value, be negative pulse.And the pulse amplitude of same phase excitation voltage is except that the zero point of modulated sinusoid voltage, always positive and negative alternate along time shaft.

Fig. 2 show the half-shadow square of motor shown in Figure 1 or 1/2 polar moment centralized field winding and with the connection diagram of excitation voltage, this winding is that independently field winding is all arranged separately on each stator tooth, therefore also can be described as free-standing field winding.For the centralized field winding of 1/2 polar moment, describe more convenient with stator tooth.As seen from Figure 2, with its 16 stator tooths, the numeral order according to 1～16, per two adjacent teeth are formed a magnetic pole, form first magnetic pole as 1,2 teeth, and 3,4 teeth are formed second magnetic pole, and 5,6 teeth are formed the 3rd magnetic pole, and the rest may be inferred, totally 8 magnetic poles; Every two adjacent magnetic poles are a pair of magnetic pole, form first pair of magnetic pole as first, second magnetic pole, and the 3rd, the 4th magnetic pole is formed second pair of magnetic pole, and the rest may be inferred, totally 4 pairs of magnetic poles.Like this, comprise two stator tooths and two stator slots in each magnetic pole, thereby two independently field windings are arranged, and insert a phase in the two-phase excitation voltage respectively by certain phase sequence.In Fig. 2, the odd number tooth in each magnetic pole, as 1,3,5,7 etc., its field winding inserts A phase excitation voltage; The even number tooth, as 2,4,6,8 etc., its field winding inserts B phase excitation voltage.The leading-in end of the excitation voltage shown in the figure for A phase excitation voltage, is respectively A1, A2 end; For B phase excitation voltage, be respectively B1, B2 end.And agreement, when excitation voltage is positive pulse, ' 1 ' end of each phase excitation voltage, i.e. A1, B1, the inflow end for exciting curent is called head end; Its ' 2 ' end, promptly A2, B2 are the outflow end of exciting curent, are called tail end.The making parameter of each field winding is all identical, and agreement, when excitation voltage is direct impulse, if by stator tooth that winding twined when the magnetomotive force that is excited on the end face of rotor is the N utmost point, then exciting curent always flows into from the head end of this winding, flow out from the tail end of winding, promptly claim the electric current inflow end of winding to be head end, the electric current outflow end is a tail end.Like this, the annexation of two field windings in each magnetic pole and excitation voltage should be able to guarantee that when the two-phase excitation voltage was all direct impulse, this magnetic pole was the N utmost point; When the two-phase excitation voltage was all negative-going pulse, this magnetic pole was the S utmost point.Each is to the antithesis magnetic pole each other of two magnetic poles in the magnetic pole, in the antithesis magnetic pole by the excitatory winding of same phase excitation voltage and by the stator tooth of its winding antithesis winding and antithesis stator tooth each other.The antithesis winding around to and should be able to guarantee always opposite each other that with the annexation of excitation voltage promptly one when being the N utmost point, then another is the S utmost point by the polarity of its excitatory stator tooth.Normally will be with the antithesis winding in a pair of magnetic pole, the winding of 1,3 teeth in the first pair of magnetic pole for example, winding of 2,4 teeth or the like, by first to head, or tail is connected into a pair of even component road to the mode of tail.Then, the antithesis branch road by equal number is connected into the parallel branch in parallel with excitation voltage again, equates that with the impedance that guarantees each parallel branch for example, the parallel branch of each phase excitation voltage is counted α=4 among Fig. 2.Fig. 3 is the expanded view of the 1/2 polar moment centralized field winding corresponding with Fig. 2, among the figure in each field winding the end with round dot ' ' be expressed as head end, the end with round dot is not expressed as tail end, each antithesis branch road is as a parallel branch, like this, the parallel branch of every phase is counted α=Z/2*M=4, uses (1), (2), (3), (4) expression respectively.If will A2, B2 in (1) end is connected with A1, B1 end in (2) respectively, the A2 in (3), B2 hold respectively with (4) in A1, B1 hold and be connected, then can make the parallel branch number of every phase reduce to α=2; If these two parallel branches two, two are together in series by the same manner again, can make the parallel branch number reduce to α=1.By basic electromagnetic theory as can be known, when field winding inserts the excitation voltage of sine wave pulse width modulated or pulse amplitude modulation, winding around to and determine with the annexation of excitation voltage after, the direction of the exciting curent that is produced in its winding is decided according to the positive and negative polarity of each excitatory pulse constantly, the amplitude of its electric current pulse duration or the pulse amplitude with excitation voltage respectively is relevant, and produces corresponding magnetomotive force on the stator tooth that winding twined.Obviously, increase the parallel branch number and can obtain bigger exciting curent, the needs of bigger power output are arranged to satisfy motor.

In Fig. 5 A, Fm represents to point out this magnetomotive maximum intensity by the magnetomotive force of modulation excitation voltage generation roughly with the quantity of the magnetic line of force, represents this magnetomotive polarity with the arrow of the magnetic line of force.Among the figure, press the connected mode of Fig. 2, field winding shown in Figure 3 and excitation voltage, the magnetomotive polarity that is encouraged by the excitatory pulse of forward on the stator tooth of correspondence is N, and the magnetic line of force points to rotor by stator tooth, represents with downward arrow; The magnetomotive polarity that is encouraged by the excitatory pulse of negative sense is S, and the magnetic line of force points to stator tooth by rotor, represents with arrow upwards.Because excitation voltage is the pulse of positive and negative alternation, so the magnetic field of Chan Shenging also is the pulsating magnetic field of positive and negative alternation therefrom.

Below, to the rotation status in the pulsating magnetic field of this positive and negative alternation and the operation logic of motor, with motor shown in Figure 1 is example, excitatory with sinusoidal wave pulse modulation excitation voltage shown in Figure 4, press the connected mode of Fig. 2, field winding shown in Figure 3 and excitation voltage, and illustrated referring to Fig. 5 A, Fig. 5 B.Be made up of left and right sides two parts shown in Fig. 5 B, (1) of left part is classified as and the width of cloth of corresponding modulated sinusoid voltage U as, the Ubs of Fig. 4 schematic diagram mutually, and its coordinate transverse axis is represented the amplitude of modulated sinusoid voltage, and the longitudinal axis is a time shaft; Right part is a plurality of components, divide (2), (3) two row are arranged along y direction and are formed, the structure of each component is identical, expression is with motor stator shown in Figure 1 and cross section of rotor, cut from A-A ' line, and the part of the expanded view after cutting open along the stator inner surface clockwise direction, hatching line with stator inner surface is a transverse axis, its origin of coordinates is positioned at the intersection point place of A-A ' line and stator inner surface, to illustrate corresponding to the several particular moments shown in Fig. 4, by the magnetomotive force of field winding generation and the running status of rotor, with the corresponding relation of modulated sinusoid voltage in this amplitude sampling value constantly.If all have tight in time adjacent positive and negative correspondingly with it to excitatory pulse for the sampling value of each particular moment, (2) row are corresponding with direct impulse among the figure, and (3) are listed as corresponding with negative-going pulse.Linking and dot in time between left and right two parts of figure.

Referring to Fig. 2, Fig. 3, as previously mentioned, excitation voltage is excitatory mutually with B mutually by A shown in Figure 4 respectively with the field winding of even number tooth for odd number tooth in each magnetic pole of the stator, as 1,3,5,7 teeth etc. is that A phase width modulated excitation voltage Uwa (or amplitude modulation(PAM) excitation voltage Uma) is excitatory, and 2,4,6,8 teeth etc. are that B phase width modulated excitation voltage Uwb (or amplitude modulation(PAM) excitation voltage Umb) is excitatory.Among the figure,, represent that with the magnetic line of force that is drawn on the stator tooth cross section each is engraved in magnetomotive force intensity and the direction that produces on this stator tooth when corresponding with the excitatory phase sequence that alphabetical A, B on the stator yoke represent corresponding stator tooth.Because the frequency F2 of modulated square wave voltage is much larger than the frequency F1 of modulated sinusoid voltage U as, Ubs, so for tight in time adjacent forward and negative-going pulse in the excitation voltage, can think and have approximate width (or amplitude) respectively, the magnetomotive force intensity that they produce in the stator tooth of correspondence is respectively also answered approximately equal, and its direction is then opposite.

Reach first row of (2), (3) row referring to (1) among Fig. 4 and Fig. 5 B row, when the time is the moment of t=00, as has maximum because of A phase modulated sinusoid voltage U, so forward and the negative-going pulse of excitation voltage Uwa also have maximum pwm value (forward of Uma and negative-going pulse also have maximum amplitude) mutually with pairing A of this moment; Bs is 0 value because of B phase modulated sinusoid voltage U, so no matter the pulsewidth (or amplitude of Uma) of pairing B phase excitation voltage Uwb of the moment is that forward or negative sense are 0 value therewith.So, by A phase excitation voltage excitatory No. 1 and No. 3 teeth maximum magnetomotive force intensity being arranged, each is represented with 4 magnetic lines of force.When excitation voltage was positive pulse, the magnetomotive force that produces at No. 1 tooth was the N utmost point, the arrow points rotor of the magnetic line of force, and the magnetomotive force that produces at No. 3 teeth is the S utmost point, the arrow points stator yoke of the magnetic line of force.Magnetomotive force intensity by No. 2 and No. 4 excitatory tooth generations of B phase excitation voltage is 0, so the quantity of its magnetic line of force also is 0.Suppose that the residing position of motor rotor just is the state shown in the figure, it is the centre that the bus that is numbered X1 and X2 in the rotor core is aimed at 1, No. 3 stator tooth just respectively, then for by the bus of X1 and X2 and and two end faces of rotor between the welding point of conducting ring part the closed galvanic circle formed jointly, can be described as the X1-X2 loop inductance, the stator segment that positive alignment is the center with No. 2 teeth.Like this, by shown in the unit of (2) row, in the X1-X2 loop inductance, the magnetic flux that flows into rotor by No. 1 stator tooth through air-gap with just equate through the magnetic flux that air-gap flows to No. 3 stator tooths by rotor core.Equally, shown in (3) row, in the X1-X2 loop inductance, the magnetic flux that flows into rotor core by No. 3 stator tooths through air-gap with also just equate through the magnetic flux that air-gap flows to No. 1 stator tooth by rotor core.Like this, because variation rate of magnetic flux is 0 in the X1-X2 loop inductance of flowing through this moment,, there is not electromagnetic force to act on X1 and X2 bus so in this closure loop inductance, can not produce induced current yet.As previously mentioned, because the consistency and the symmetry of the structure of motor stator and rotor, other all in rotor closed loop inductances also are in same state.Because all buss all are not subjected to the effect of any electromagnetic torque in the rotor, so rotor can not rotate.

And the time by t=00 through t=02 in the variation of t=04 crosses, situation is just different, in Fig. 5 B in (2) row and (3) column unit of two rows, show with (1) row t=02 constantly corresponding, by positive and negative to magnetomotive intensity and direction that excitatory pulse produced.As seen, the amplitude of A phase modulated sinusoid voltage U as when t=02 reduces to some extent than its amplitude when the t=00, the pulsewidth of Dui Ying excitation voltage Uwb (or amplitude of Uma) also has accordingly and reduces therewith, therefore, the magnetic line of force for the magnetomotive force intensity of No. 1 tooth of expression and No. 3 teeth in the unit of (2) row reduces to 3 by 4, and wherein No. 1 tooth arrow points rotor is the N utmost point, arrow points stator yoke on No. 3 teeth is the S utmost point; The amplitude of B phase modulated sinusoid voltage U bs when t=02 increases to some extent than its amplitude when the t=00, the pulsewidth of Dui Ying excitation voltage Uwb (or amplitude of Uma) also has corresponding increase therewith, therefore, the magnetic line of force for the magnetomotive force intensity of No. 2 teeth of expression and No. 4 teeth in the unit of (2) row is increased to 1 by 0, the arrow points rotor on No. 2 teeth wherein, be the N utmost point, the arrow points stator yoke on No. 4 teeth is the S utmost point.The position when if the closed loop inductance of the rotor of motor and X1-X2 thereof still is in t=00, so, because variation has taken place in the magnetomotive force that is excited on each stator tooth corresponding with it, in closed loop inductance X1-X2, by 1, No. 2 stator tooth flows to the magnetic flux of rotor core greater than the magnetic flux that is flowed to No. 3 stator tooths by rotor core through air-gap through air-gap, therefore, by the electromagnetic induction theorem as can be known, on the X1-X2 closed-loop path, can produce the induced current shown in the figure, its direction is that the electric current among the bus X1 relative with No. 1 stator tooth is outside, electric current among the bus X2 relative with No. 3 stator tooths is inside, like this, on X1 and two buss of X2, can be subjected to promptly clockwise electromagnetic force simultaneously to the right with respect to magnetic pole of the stator.Because the consistency and the symmetry of the structure of motor stator and rotor, also can be subjected to same electromagnetic force on the bus in rotor in all other closed loop inductance, thereby rotor can make clockwise direction with respect to stator and rotate, until the balance point that arrives moment.Almost at synchronization, in the unit shown in (3) row, if the width of its excitatory pulse (or amplitude) does not almost change, just direction is opposite, promptly become negative pulse by positive pulse, so the magnetic line of force quantity of expression magnetomotive force intensity does not become among the figure, but the direction of the magnetic line of force is compared opposite with (2) row.If the closed loop inductance of rotor and X1-X2 thereof is the balance point that of positive pulse has arrived moment constantly at excitation voltage, obviously, just do not have induced current in this closure loop inductance, rotor can not rotate yet; If the closed loop inductance of X1-X2 is the balance point that of positive pulse does not also arrive moment as yet fully constantly at excitation voltage, then can produce and the opposite induced current of direction during (2) are listed as at the closed loop inductance of X1-X2, but because the magnetomotive force corresponding with bus X1, X2 is also reverse, so its electromagnetic force can make the original direction of motion of this loop maintenance constant, until arriving balance point.Arrive t=04 situation constantly when the time, be shown in respectively in the unit of Fig. 5 B three row (2) row and (3) row, according to same principle, rotor also can be made clockwise direction equally with respect to stator and rotate, until the balance point that arrives new moment.Only otherwise change excitatory phase sequence, the pulsating rotating magnetic field of this alternation, and the direction of the electromagnetic torque that produces in each bus of its rotor can not become yet.

By Fig. 5 B as seen, when the t=00 when the time from figure changes to t=08, modulated sinusoid voltage has passed through the time in 1/4 cycle in the excitation voltage, bus X1, X2 are with one position from 1, No. 3 stator tooths of difference positive alignment of motor rotor, rotate to the position of 2, No. 4 stator tooths of positive alignment respectively, tooth that is turned over or groove number are 1.Can conclude that when modulated sinusoid voltage during through 1/2 cycle, tooth that motor rotor turned over or groove number are 2, are the space angle of a pole span (representing with τ among the figure).When modulated sinusoid voltage during through 1 cycle, then motor rotor just turns over the space angle of a pair of utmost point, be rotor rotation 1/P circle, the per minute rotating speed that can calculate this kind motor thus is: n=60*F1/P is identical with the rotating speed formula of aforesaid heritage induction motor.But for this motor, because the frequency F1 of its modulated sinusoid voltage can be infinitely near 0 value, so its rotating speed also can be infinitely near 0.Can see that when the excitatory phase sequence of exchange stator winding, the field winding that is about to odd number tooth 1,3,5,7 etc. changes into by B phase excitation voltage Uwb (or Umb) excitatory, change into A phase excitation voltage Uwa (or Uma) such as even number tooth 2,4,6,8 when excitatory; Perhaps, it is constant to keep original excitatory phase sequence, and arbitrary in the two-phase excitation voltage changed into the excitation voltage reverse with former excitation voltage (this reverse excitation voltage can be considered by this excitation voltage of producing of modulated sinusoid voltage and negative sense modulated square wave voltage modulated mutually) mutually, can make the rotation commutation of rotor.

Similar to traditional induction motor, the constituted mode of this novel motor field winding neither be unique.Fig. 6 A～8B shows motor shown in Figure 1, several whole constituted mode when Q=1 apart from field winding, wherein: Fig. 6 A is depicted as that A is whole mutually to connect into the schematic diagram of a parallel branch apart from single layer winding, and the field winding in this branch road is firstly connected to head to tail or tail by it.Fig. 6 B is the whole apart from the single layer winding connection diagram of A, B two-phase, and parallel branch is counted α=2 among the figure, uses (1), (2) expression respectively.If will A2, B2 in (1) end respectively with (2) in A1, B1 hold and be connected, then can make the parallel branch number of every phase reduce to α=1.This winding construction is simple, has only a circle limit in each stator slot, is fit to the motor of smaller power.Fig. 7 A illustrates by excitatory whole apart from chain type winding connection diagram of A phase excitation voltage, and each field winding is composed in series a parallel branch, i.e. α=1 to head or tail to the mode of tail by first among the figure.Fig. 7 B illustrates excitatory whole apart from chain type winding connection diagram by A, B two-phase excitation voltage, and two circle limits are all arranged in each stator slot, and the parallel branch of every phase is counted α=4 among the figure, uses (1), (2), (3), (4) expression respectively.If will A2, B2 in (1) end is connected with A1, B1 end in (2) respectively, with A2, B2 in (3) hold respectively with (4) in A1, B1 hold and be connected, then can make the parallel branch number of every phase reduce to α=2.Fig. 8 A illustrates by excitatory whole apart from the wave winding connection diagram of A phase excitation voltage, and the parallel branch among the figure is counted α=2.Fig. 8 B illustrates excitatory whole apart from the wave winding connection diagram by A, B two-phase excitation voltage, and the parallel branch number of every phase still is 2 among the figure, if the homophase field winding is connected according to the sense of current, can make the parallel branch number of every phase reduce to α=1.

Because these are whole identical in itself with the magnetic field that winding excited of 1/2 pole span apart from the magnetic field that field winding excited, so the front is suitable too for the analysis of the operation principle under the winding mode of 1/2 pole span.The utility model do not repel with more than the field winding enumerated other forms of field winding with equivalent function.

Figure 9 shows that the transverse cross-sectional view of 4 pairs of utmost point threephase switches of 24 grooves formula induction electric machine stator and rotor.Among the figure, " 010 " is stator core, " 101 " are stator slot, " 102 " are stator yoke, " 103 " are stator tooth, " 020 " is for there being the rotor of garden cylinder surface, " 104 " are bus, bus and the conducting ring (figure does not draw) that is arranged on cylindrical two end faces are fused into the metal inductor that is similar to cage-shaped structure, " 105 " are rotor core, " 106 " are armature spindle, and " 107 " are the air-gap between rotor and the stator, and armature spindle is supported by the rotor bearing (figure does not draw) that is arranged on the support that fuses with stator core.As seen from the figure, establish Q=1, the number of phases M=3 of the excitation voltage of motor, the quantity Z=24 of its stator slot [101] or tooth [103], magnetic pole logarithm P=Z/ (2*M*Q)=4 has 8 buss in the rotor, be 2 times of magnetic pole logarithm 4.

With 24 stator tooths among Fig. 9, the numeral order according to 1～24, per three adjacent teeth are formed a magnetic pole, form first magnetic pole as 1,2,3 teeth, and 4,5,6 teeth are formed second magnetic pole, and 7,8,9 teeth are formed the 3rd magnetic pole, and the rest may be inferred, totally 8 magnetic poles; Every two adjacent magnetic poles are a pair of magnetic pole, form first pair of magnetic pole as first magnetic pole and second magnetic pole, and the 3rd magnetic pole and the 4th magnetic pole are formed second pair of magnetic pole, and the rest may be inferred, totally 4 pairs of magnetic poles.Because each magnetic pole has three stator tooths, three stator slots and three independent winding, and be divided into three groups by its relative tertiary location in each magnetic pole, field winding as 1 among Figure 10,4,7,10,13,16,19,22 teeth is the 1st group, 2, the field winding of 5,8,11,14,17,20,23 teeth is the 2nd group, 3, the field winding of 6,9,12,15,18,21,24 teeth is the 3rd group, inserts the phase in the three-phase excitation voltage respectively.

Figure 11 is the waveform schematic diagram of the three-phase pulse excitation voltage of motor shown in Figure 9.Among the figure, Ur is a modulated square wave voltage, and Uas, Ubs, Ucs are A, B, C three-phase modulations sine voltage, and the leading Ubs120 of Uas ° angle, the leading Ucs hexagonal angle of Ubs, the leading Uas hexagonal angle of Ucs.As seen from the figure, for the polarity orientation principle of the pulse amplitude of the excitation voltage of pulse duration (or amplitude) modulation still as previously mentioned, promptly just get in the same way the time, get negative when incorgruous when the amplitude of its modulated sinusoid voltage and modulated square wave voltage.The pulse amplitude of same phase excitation voltage is except that the zero point of modulated sinusoid voltage, always positive and negative alternate along time shaft.

Figure 10 is the centralized field winding expanded view of 1/3 pole span in the motor shown in Figure 9, the leading-in end of its excitation voltage, and the definition of the head end of field winding and tail end and expression symbol are identical with the above.Among the figure, the field winding of each tooth during A phase excitation voltage Uwa (or Uma) inserts above-mentioned the 1st group, the field winding of each tooth during C phase excitation voltage Uwc (or Umc) inserts above-mentioned the 2nd group, the field winding of each tooth during B phase excitation voltage Uwb (or Umb) inserts above-mentioned the 3rd group, such phase sequence is rotated motor shown in Figure 9 in the direction of the clock, so be called clockwise excitatory phase sequence.If phase sequence exchange with any two-phase excitation voltage, as three-phase pulse modulation excitation voltage shown in Figure 11 is pressed Uwa (or Uma), Uwb (or Umb), Uwc (or Umc) phase sequence, insert the field winding of each tooth in above-mentioned the 1st, 2,3 group respectively, then can make motor counter rotation shown in Figure 9, so be called counter-clockwise excitatory phase sequence.Among the figure, all antithesis winding is adopted first to head, or tail is connected into an antithesis branch road to the mode of tail, and each bar antithesis branch road is all as a parallel branch, like this, the parallel branch number of every phase is α=Z/2*M=4, uses (1), (2), (3), (4) expression respectively.If will A2, C1 in (1), the B2 end is connected with A1, C2, B1 end in (2) respectively, the A2 in (3), C1, B2 hold respectively with (4) in A1, C2, B1 hold and be connected, then can make the parallel branch number of every phase reduce to α=2.If these two parallel branches two, two are together in series by the same manner again, can make the parallel branch number of every phase reduce to α=1.

Figure 12 illustrates the excitation voltage with Figure 11 institute formula, the pulsating rotating magnetic field and the rotor operation schematic diagram that produce when excitatory by above-mentioned clockwise excitatory phase sequence.Still be made up of left and right sides two parts shown in the figure, (1) of left part is classified the width of cloth phase schematic diagram of A, B among Figure 12, C phase modulated sinusoid voltage U as, Ubs, Ucs as, and its coordinate transverse axis is represented the amplitude of modulated sinusoid voltage, and the longitudinal axis is a time shaft; (2) of right part classify a plurality of components as, form along the y direction arrangement by row, the structure of each component is identical, expression is with motor stator shown in Figure 9 and cross section of rotor, cut from A-A ' line, and the part of the expanded view after cutting open along the stator inner surface clockwise direction, hatching line with stator inner surface is a transverse axis, its origin of coordinates is positioned at the intersection point place of A-A ' line and stator inner surface, to illustrate for the several particular moments shown in Figure 11, stator tooth that produce with running status magnetomotive force and rotor, with the corresponding relation of modulated sinusoid voltage in this amplitude sampling value constantly.Process is established for the sampling value of each particular moment and is had only the excitatory pulse of a forward or negative sense corresponding with it for simplifying the analysis, and alternately occurs by the time sequencing of sampling.Linking and dot in time between left and right two parts of figure, the symbol among the figure is used identical with above institute with the definition of expression way.As seen from the figure, when t=03, bus X1, X2 are respectively in the position of aiming at No. 3 and No. 6 stator tooths, when t=21, excitation voltage just experienced for 1/2 cycle, then bus X1, X2 rotate to the position of aiming at No. 6 and No. 9 stator tooths respectively together with rotor, have promptly turned over the space angle of a pole span (representing with τ among the figure).When modulated sinusoid voltage during through 1 cycle, then motor rotor just turns over the space angle of a pair of utmost point, i.e. rotor rotation 1/P circle, like this, for threephase motor shown in Figure 9, the computing formula of its rotating speed is identical with above-described two-phase motor.Figure 13 illustrates the excitation voltage with Figure 11 institute formula, the pulsating rotating magnetic field and the rotor operation schematic diagram that produce when excitatory by the excitatory phase sequence of above-mentioned inhour.As seen from the figure, the phase sequence change owing to excitation voltage makes the motor counter-rotating.

Figure 14 A～16B shows motor shown in Figure 9, several whole constituted mode when Q=1 apart from field winding, wherein: Figure 14 A is depicted as that A is whole mutually to connect into the schematic diagram of a parallel branch apart from single layer winding, and the field winding in this branch road is firstly connected to head to tail or tail by it.Figure 14 B is the whole apart from the single layer winding connection diagram of A, B, C three-phase, and parallel branch is counted α=2 among the figure, uses (1), (2) expression respectively.If will A2, C1 in (1), the B2 end respectively with (2) in A1, C2, B1 hold and be connected, then can make the parallel branch number of every phase reduce to α=1.This winding construction is simple, has only a circle limit in each stator slot, is fit to the motor of smaller power.Figure 15 A illustrates by excitatory whole apart from chain type winding connection diagram of A phase excitation voltage, and each field winding is composed in series a parallel branch, i.e. α=1 to head or tail to the mode of tail by first among the figure.Figure 15 B illustrates by excitatory whole apart from chain type winding connection diagram of A, B, C three-phase excitation voltage, and two circle limits are all arranged in each stator slot, and the parallel branch of every phase is counted α=4 among the figure, uses (1), (2), (3), (4) expression respectively.If will A2, C1 in (1), the B2 end is connected with A1, C2, B1 end in (2) respectively, with A2, C1 in (3), B2 hold respectively with (4) in A1, C2, B1 hold and be connected, then can make the parallel branch number of every phase reduce to α=2.If in the same way, can make the parallel branch number of every phase reduce to α=1.Figure 16 A illustrates by excitatory whole apart from the wave winding connection diagram of A phase excitation voltage, and the parallel branch among the figure is counted α=2.Figure 16 B illustrates by excitatory whole apart from the wave winding connection diagram of A, B, C three-phase excitation voltage, and the parallel branch number of every phase still is 2 among the figure, if the homophase field winding is connected according to the sense of current, can make the parallel branch number of every phase reduce to α=1.

Figure 17 is depicted as the pulse width modulation excitation control circuit block diagram of 4 pairs of utmost point threephase motors of 24 grooves shown in Figure 9.By the Synchronization Control pulse of clock signal generating unit [11] output, deliver to modulated square wave generating unit [12] and frequency conversion sine voltage generating unit [13] respectively among the figure.By the three-phase of frequency conversion rate sine voltage generating unit output, and have the modulated sinusoid voltage U as, Ubs, Ucs of the changeable frequency of 120 ° of phase differences and modulated square wave voltage U r each other and after the pulse width modulation of pwm unit [14] realization micropower, remove to drive device for power switching in the main switch unit [16] respectively through A, C, B three-phase drive unit [15] by the output of modulated square wave generating unit.The main switch unit is to form three groups of direct current semibridge system switching circuits jointly by 6 power field effect switching tubes and 6 electric capacity, and under the control of drive circuit, two switching tubes in each direct current semibridge system switching circuit take turns conducting and ending, thereby respectively by A1, A2; C1, C2; The excitation voltage of B1, B2 output three-phase pulse width-modulated gives the stator winding of motor excitatory.This circuit power device is few, and the circuit of control section can adopt analog form, or adopts digital form, also can be integrated into special circuit, and place in the motor with power device, with its overall dimension of further minimizing.The Dc low voltage power supply that high direct voltage that high and low pressure DC power supply generation unit [17] output main switch circuit needs and integrated circuit are used.

Figure 18 is depicted as the pulse amplitude modulation excitation control circuit block diagram of 4 pairs of utmost point threephase motors of 24 grooves shown in Figure 7.As seen from the figure, the characteristics of this circuit are under the synchronizing signal control of clock signal generating unit [21] output, modulated square wave voltage by modulated square wave generating unit [22] output directly promotes driver element [25], is exported modulated sinusoid voltage U as, Ubs, the Ucs of the three phase variable frequency with enough power and amplitude by the synchronous frequency conversion control unit of clock signal generating unit [23] control of conversion sine voltage generating unit [24].The modulated square wave of this modulated sinusoid voltage and driver element output in main switch unit [26] by form three groups of amplitude modulation(PAM)s that exchange the realization of semibridge system switching circuit to the power sine voltage jointly by 12 power field effect switching tubes and 6 electric capacity, again by its output terminals A 1, A2; C1, C2; B1, B2 export three-phase amplitude modulation(PAM) excitation voltage respectively.The Dc low voltage power supply that low-voltage dc power supply generation unit [27] output integrated circuit is used.

Obviously, can realize equally the pulse width modulation of 4 pairs of utmost point two-phase motors of 16 grooves shown in Figure 1 and the excitatory control of pulse amplitude modulation with aforesaid way.The present invention does not repel other control circuit with above-mentioned equivalent function.

Claims (4)

1. audio Switch type AC induction motor, by support, stator and rotor are formed, stator core is the garden tubular, its inner surface has the stator tooth by the angle same distribution that radially inwardly stretches, it between tooth and tooth the stator slot that connects vertically, the quantity Z of its stator slot or tooth is determined by following formula: Z=2*M*P*Q, wherein, M is the number of phases of excitation voltage, P is the logarithm of magnetic pole of the stator, Q is the quantity of the groove or the tooth of every extremely every phase, field winding is put in the stator slot, motor rotor adopts cage-shaped structure, the excitation mode that it is characterized in that the motor stator field winding, adopt the excitatory technology of switch AC pulsed, excitation voltage is that its effective value and frequency equate, and two-phase with 90 ° of phase differences, or the continuous sine voltage of the three-phase with 120 ° of phase differences, can be described as modulated sinusoid voltage, pulse square wave voltage with audio frequency or superaudio scope, can be described as modulated square wave voltage, make the pulse modulation voltage after pulse duration or the pulse amplitude modulation, can claim sinusoidal wave pulse modulation excitation voltage; The quantity K of parallel electrically conductive bar should equal 2 times of magnetic pole of the stator logarithm P in the metal inductor of rotor upper cage structure, and promptly K=2P is spacedly distributed along rotor outer surface.

2. motor according to claim 1 is characterized in that the structure of stator field winding forms, and as the quantity Q=1 of every extremely every phase groove or tooth, adopts the centralized winding of 1/M pole span or whole distance.

3. motor according to claim 1 is characterized in that the structure of stator field winding forms, and when quantity Q＞1 of every extremely every phase groove or tooth, adopts distributed winding.

4. according to claim 1 and 2 described motor, the iron core that it is characterized in that its stator and rotor is by the soft magnetic material punching of the corresponding frequencies characteristic that satisfies audio frequency and superaudio scope and do to be overrided to form vertically after the surperficial insulation processing, or the mode of or vertically segmentation whole by the ferrite material using with corresponding frequencies characteristic is made.

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