CN1065083C

CN1065083C - AC motor rotor winding using circulating current removing technique and connecting method thereof

Info

Publication number: CN1065083C
Application number: CN94117445XA
Authority: CN
Inventors: 王雪帆; 张帮发
Original assignee: Yangtze River Shipping Corp Electric Machinery Factory; Huazhong University of Science and Technology
Current assignee: China Changjiang National Shipping Group Motor Factory
Priority date: 1994-12-12
Filing date: 1994-12-12
Publication date: 2001-04-25
Anticipated expiration: 2014-12-12
Also published as: CN1124882A

Abstract

The present invention relates to an ac motor rotor winding and a connection method thereof using a circulatory flow removal technique. Each winding coil has two sub coils with unequal numbers of turns, and two winding coils with a mechanical angle of alpha along the circumference of a rotor are in series connected into a branch with another sub coil with fewer turns according to a coil with multiple turn, wherein the sub coil with fewer tyrns is in series connected with another sub coil with multiple turn into a branck, and then two branches are in parallel connected into a coil pair. A phase winding uses a coil as a base unit and is formed by the parallel connection or the in series connection os the coils. The present invention is suitable for line winding type pole changing motors with a distal pole ratio, and can meet the requirements of heavy-load starting, frequent starting, creeping starting and targeting braking or accurate parking.

Description

A kind of ac pole-changing motor

The invention belongs to AC motor rotor winding attached method and structure.

Present pole-changing induction motor mostly is the cage modle motor greatly, because its rotor itself does not have definite number of poles, the number of poles of motor only is decided by stator, and when the stator winding number of poles changed, the rotor number of poles was capable of automatic changing.And common wound motor is not like this.The wound motor rotor has definite number of poles, and when the stator winding number of poles changed, the rotor number of poles can not change automatically thereupon, but must change the number of poles of rotor winding simultaneously, otherwise motor can not be worked.

The pole-changing of wound rotor winding generally can adopt the way similar with the stator winding pole-changing, and rotor winding at this moment needs 6 outlets to draw through slip ring at least.But, three slip rings generally only are housed on the common wound motor rotor, if 6 lines all will be drawn, must install three slip rings additional, so not only need to change rotor structure, and understand the frictional dissipation that increase between slip ring and brush meaninglessly, too much lead-out wire also can make the pole-changing transition apparatus complicated simultaneously.Therefore, but the wound motor of pole-changing also preferably only with three slip rings.Chinese patent No.92212670 just proposes " a kind of multipole proportion pole-changing-rotor winding ", makes three lead-out wires of its rotor winding only connect the scheme of three slip rings.

The objective of the invention is to propose a kind of new wound-rotor rotor winding coil connecting scheme, make the winding-type pole-changing induction motor that adopts this coil attachment to make only need three slip rings, wherein have under a kind of number of poles the same with common winding-type motor, rotor can seal in impedance, and other number of poles is next high starting torque and low starting current or good runnability.

Basic structure of the present invention is: the mechanical structure of each parts of motor is the same with common Wound induction motor, three slip rings are arranged on the rotor, stator adopts variable-pole winding, but the rotor winding coil adopts special construction, it adopts special arrangement in rotor, adopt special connection between coil, specific as follows.

1. rotor winding coil constituted mode

Each rotor winding coil constitutes (as shown in Figure 1) by two subcoils, and one of them subcoil number of turn is more, have n+m (n=1,2,3, M=0,1,2 ...) circle; Another subcoil number of turn is less, and the m circle is arranged, and each subcoil all has head, two lead-out wires of tail.Rotor coil also can constitute coil groups, and at this moment the connecting method (as shown in Figure 2) between the subcoil is in the coil groups, and multiturn is counted subcoil and counted subcoil with multiturn and be connected in series, and the formation multiturn is counted coil groups; Few number of turn subcoil is connected in series with few number of turn coil, constitutes few number of turn coil groups.

2. the method for attachment between the rotor winding coil

Is two coils of α along rotor circumference at a distance of mechanical angle, (α determines when design according to concrete motor requirement), and the connecting method between them is: the multiturn subcoil of a coil is connected with few circle subcoil of another coil, forms a branch road; Few circle subcoil then is connected with the multiturn subcoil of another coil, forms another branch road, and the number of turn of two branch roads is identical, and these two branch roads are connected in parallel again then, and it is right to form a coil, and coil is two (as shown in Figure 3) to lead-out wire.The rotor phase winding promptly with this coil with two parallel branches to carry out as elementary cell and or series connection constitute, accompanying drawing 4 for every phase winding with the example of coil to the three-phase winding coupling method that is connected in series.More than shown in coil or subcoil, also can be coil groups or subcoil group.

3. the rotor winding coil arrangement of coil side in rotor that comprise two subcoils can have multiple.When adopting the coiling of circle enamelled wire as coil, can be earlier and around the m of two subcoils circle, after finishing the m circle of few number of turn coil and multiturn subcoil, again separately around the n of multiturn subcoil circle, when in groove, placing, the m circle of the few number of turn coil of two subcoils can be placed on bottom, and multiturn is counted the n circle of subcoil and is placed on the upper strata; Also can be with the coiling respectively of two subcoils, placed apart or mixing placement in groove.When coil adopts square-section lead coiling, also can adopt with the above similar groove in laying method.

Basic principle of the present invention is described as follows: when stator adopts variable-pole winding, and switch when can produce number of pole-pairs respectively and being the rotating magnetic field of p and two kinds of numbers of poles of q by switching device, two coil design that constitute parallel branch as shown in Figure 3 in the rotor winding become: for p to the utmost point, induced electromotive force phase place wherein is identical, to the utmost point, induced electromotive force phase place wherein is opposite for q.Like this, as the induced electromotive force size of establishing multiturn subcoil wherein be E _N+m, the induced electromotive force size of few circle subcoil is E _m, E _N+m/ E _m, like this, p presses the equal and opposite in direction of the coil of connection shown in the accompanying drawing 3 to the synthetic induced electromotive force of the branch road in two parallel branches during to the utmost point, promptly is E _N+m+ E _m, phase place is identical, and coil is to the acyclic stream in inside, and the electric current that induced electromotive force produces in the rotor winding can only be by slip ring and the rotor impedance formation loop of connecting outward; Q is during to the utmost point, and coil reduces the synthetic induced electromotive force of the branch road in two parallel branches, but size still equates, promptly is E _N+m-E _m, and phase place is opposite, the electric current that induced electromotive force produces in the rotor winding can not form the loop by slip ring and rotor guest performer impedance, and can only closure circulate in the internal portion of coil parallel branch, forms and is surrounded on the circulation of coil to inside.Because stator field is when p changes to q to the utmost point to the utmost point, the size of rotor branch road induced electromotive force is from E _N+m+ E _mBe reduced to E _N+m-E _mPhase place is changed on the contrary by identical, will produce two effects when q is to the utmost point like this: 1) rotor winding effective turn reduces, each coil effective turn reduces to the n circle by original n+2m circle, because square being inversely proportional to the rotor parameter of converting stator of rotor winding effective turn, at this moment the rotor resistance of converting stator will enlarge markedly; 2) because the phase place of two branch road induced electromotive forces is opposite, article two, it is also opposite to flow through sense of current in the branch road, the sense of current that two sub-coil midstreams of formation rotor coil are crossed is opposite equally, arrange proper as the relative position of these two subcoils in rotor, can make most of counteracting of stray field of its generation, thereby the rotor leakage reactance is remained unchanged or reduce.According to the induction motor theory, these two effects will increase starting torque, reduce starting current simultaneously, the starting characteristic when significantly improving q to the utmost point.

The present invention is particularly suitable for designing the winding-type pole-changing induction motor of distal pole ratio, at this moment be typically designed at a high speed and can pass through slip ring guest performer impedance, to satisfy the manufacturing machine that drags the potential energy load or have high inertia, as railway car tipper etc., the requirement of Fraquent start and general speed governing, low speed then put in place or the requirement of accurate stopping in order to satisfy creep starting and the braking that the potential energy load transfers with high inertia manufacturing machine.The present invention also can be designed to the proximal pole ratio, and at this moment a kind of speed can be used as common Wound induction motor and equally uses, and another kind of speed then can be used as in particular cases overload and rises and employ.Because the present invention can have the height impedance at two kinds of number of poles lower rotor parts, therefore, no matter be, or at a high speed under operating modes such as the direct switchover operation of low speed, impulse current is all less in the high speed across-the-line starting or in the low speed across-the-line starting.

Accompanying drawing 1: two subcoils of rotor winding coil;

Accompanying drawing 2: two sub-coil groups of rotor winding coil;

Accompanying drawing 3: coil is right;

Accompanying drawing 4: by three phase windings of coil to being connected in series.

Claims

1, a kind of ac pole-changing motor is characterized in that, each rotor winding coil all contains two subcoils that two numbers of turn do not wait, and one of them subcoil number of turn is more, have n+m (n=1,2,3 ...: m=0,1,2 ...) circle; Another subcoil number of turn is less, the m circle is arranged, each subcoil all has head, two lead-out wires of tail, it is right to be at a distance of mechanical angle that two winding coils of α connect into coil along rotor circumference, with coil to being elementary cell, as adopting unicoil to make a kind of number of poles standard three phase windings of elementary cell, in parallel or series connection constitutes the rotor three-phase winding, and rotor three-phase winding lead-out wire is connected with epitrochanterian three slip rings; Stator winding can produce p and two kinds of numbers of poles of q, two coil design that constitute parallel branch in the rotor winding become: for p to the utmost point, induced electromotive force phase place wherein is identical, then coil is to the equal and opposite in direction of the synthetic induced electromotive force of the branch road in two parallel branches, phase place is identical, coil is to the acyclic stream in inside, and the electric current that induced electromotive force produces in the rotor winding can only be by slip ring and the rotor impedance formation loop of connecting outward; For q to the utmost point, induced electromotive force phase place wherein is opposite, coil is to the synthetic induced electromotive force equal and opposite in direction of the branch road in two parallel branches, phase place is opposite, the electric current that induced electromotive force produces in the rotor winding can not form the loop by slip ring and rotor guest performer impedance, can only in two parallel branches of the internal portion of coil, closure circulate, form and be surrounded on the circulation of coil inside.

According to the described ac pole-changing motor of claim 1, it is characterized in that 2, said coil is to being that few circle subcoil of the multiturn subcoil of a coil and another coil is in series, and forms a branch road; Few circle subcoil then is in series with the multiturn subcoil of another coil, forms another branch road, and the turns-in-series of two branch roads is identical, and these two branch roads are connected in parallel again then, and it is right to form a coil, and coil is two to lead-out wire.

3, according to the described ac pole-changing motor of claim 1, it is characterized in that, said rotor winding coil is a coil groups, and the multiturn that constitutes of coil groups is counted the subcoil multiturn that constitutes that is connected in series and counted the subcoil group, and few number of turn subcoil is connected in series and constitutes few number of turn subcoil group.

According to claim 1 or 3 described ac pole-changing motors, it is characterized in that 4, said coil is to being that few circle subcoil group of the multiturn subcoil group of a coil and another coil is in series, and forms a branch road; Few circle subcoil group then is in series with the multiturn subcoil group of another coil, forms another branch road, and the branch road turns-in-series of two branch roads is identical, and these two branch roads are connected in parallel again then, and it is right to form a coil, and coil is two to lead-out wire.