CN2205605Y

CN2205605Y - Double stator double magnetic loop squirrel-cage ac speed adjusting motor

Info

Publication number: CN2205605Y
Application number: CN 94238375
Authority: CN
Inventors: 王逸民
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-10-14
Filing date: 1994-10-14
Publication date: 1995-08-16
Anticipated expiration: 2004-10-14

Abstract

The utility model relates to an AC asynchronous speed-regulating motor, which solves the problems of the small regulating range and the poor natural characteristic of the existing AC motor. The utility model is composed of two groups of independent stator cores and the windings of the stator cores, wherein, the two groups of the independent stator cores and the windings of the stators together act on a group of rotors of a squirrel-cage motor; the windings of two groups of the stators are respectively connected with different power supplies; the phase angles of the windings of one group of the stators are changed by a phase shifter to reach the purpose of speed regulation. The utility model has all the advantages of an AC squirrel-cage motor, and the speed regulating range of the AC asynchronous speed-regulating motor can be smoothly regulated from 0 to rated rotation speed. The utility model has the good natural characteristic, and is one more ideal AC speed-regulating motor.

Description

Double stator double magnetic loop squirrel-cage ac speed adjusting motor

The utility model relates to a kind of ac induction motor speed, particularly a kind of cage ac governor motor having double stator double magnetic loop.

Since exchanging the asynchronous motor appearance, people go deep into extensive studies to the speed governing problem of AC induction motor always.Mouse cage AC motor particularly, to have a process manufacturing technology simple because of it, the reliability height of motor own, no electric contacts, the advantage that cost is low, and be widely used, but the speed governing problem of mouse cage AC motor does not obtain desirable solution in decades always.People's basic concept thinks that the governor control characteristics of AC asynchronous motor is not good at present, flatness with regard to its speed adjustable range and speed governing all can not be compared with DC motor, mechanical load as need speed governing in broad range, asynchronous motor just can not adopt, utilize dc motor speed regulating, though it has good natural external characteristic, but because direct current machine process manufacturing technology complexity, the reliability of motor own is low, electric contacts is arranged, the shortcoming that cost is high also is restricted on using.The speed regulating method of existing asynchronous motor is: change the frequency of power supply, change the number of pole-pairs of motor, change revolutional slip, though these speed regulating methods also can speed governing, applicable scope be limited.

The purpose of this utility model is to provide a kind of whole advantages with mouse cage AC motor to have again or very near the cage ac governor motor having double stator double magnetic loop of the governor control characteristics of direct current machine.

The utility model is finished with following mode: cage ac governor motor having double stator double magnetic loop, it is included in rotor core and winding 9 thereof is housed on the support 1, two groups of independently stator cores 2 and 3 are housed respectively in the support 1, on stator core 2, be embedded with three-phase stator winding 4, be embedded with three-phase stator winding 5 on stator core 3, rotor core and winding 9 thereof intert among stator core 2 and 3.Rotor core and winding 9 thereof are that two sections independently respectively corresponding two groups of stator cores 2 and 3 independently of rotor core 8 and 7 are housed in rotating shaft 6, at two sections setting-in one group rotor windings 9 on the rotor core 8 and 7 independently.

The utility model cage ac governor motor having double stator double magnetic loop is simple in structure, no electric contacts, and the reliability height, cost is low, because its structure and mouse cage AC electric machinery are seemingly, so it has all advantages of mouse cage AC motor.Its speed-regulating range width can be transferred to rated speed by 0 always, and the good stability of speed governing, has the performance near DC motor speed-regulating on governor control characteristics.Its power factor (PF) height, electrical network there is not any pollution, its natural characteristic can need be adjusted by using, adopt different parameters can obtain characteristics such as permanent commentaries on classics, short permanent power, permanent rotating speed, matching with control system can obtain and the similarly artificial characteristic of frequency control, and the utility model has wide application prospect aspect asynchronous motor drive.

Fig. 1 is the utility model structural representation

Fig. 2 is the utility model equivalent circuit diagram

Below in conjunction with accompanying drawing the utility model is described in further detail:

As shown in Figure 1, the utility model cage ac governor motor having double stator double magnetic loop is by arranging in support 1 two groups of independently stator cores 2 and 3 to be housed, rotor core and mouse cage winding 9 thereof intert at two groups independently among the stator core 2 and 3, on stator core 2, be embedded with three-phase stator winding 4, on stator core 3, be embedded with three-phase stator winding 5, rotor core and mouse cage winding 9 can be common squirrel-cage motor rotor structures, and be just long than common squirrel-cage motor rotor; Because of it will intert at two groups independently among the stator core 2 and 3 simultaneously, but adopt this structure will consume some materials undoubtedly more, also increase simultaneously some electric energy losses, so preferably adopt rotor structure as shown in Figure 1, promptly in rotating shaft 6, divide two sections installing rotor cores 8 and 7 corresponding stator core 2 and 3 respectively, one group of mouse cage winding 9 of installing on two-stage rotor iron core 8 and 7, between two-stage rotor iron core 8 and 7, use the insulating material filling, such rotor structure can not only be saved metal material, and can reduce electric energy loss, improve electric efficiency, rotating shaft 6 is contained in the bearing on support 1 two end cap.This motor and common squirrel-cage motor structure are very similar, just many one group of stator cores and three-phase stator winding, its threephase stator winding 4 power supply that gets access to grid, threephase stator winding 5 power supply that gets access to grid behind phase shifter can reach the purpose of speed governing by the phase place of regulating power supply in the stator winding 5.

The operation principle of the utility model cage ac governor motor having double stator double magnetic loop is:

In the mouse cage AC motor, air-gap field, exciting curent is provided by line voltage, and the exciting curent of stator produces rotating magnetic field in air gap, and the fundamental equation of mouse cage AC formula motor is:

From above-mentioned fundamental equation as seen, r ^' ₂And x ^' ₂It is all very little,

Approaching

, then motor will be operated under certain electrical power condition, and revolutional slip S must be very little, and promptly motor will move with leg speed approaching.

The utility model double stator double magnetic loop cage ac motor, possess two independently stator core and windings thereof simultaneously, epitrochanterian structure and common squirrel-cage motor are just the same, just iron core is divided into two sections, middle one section no iron core, the rotor winding has only one group, and is under two groups of stator cores and the winding thereof, two groups of stator winding are connected to power supply separately, and equivalent circuit diagram as shown in Figure 2.

Equivalent circuit diagram shown in Figure 2 is divided into A and B both sides with this motor, also is that stator core 2 and winding 4 are made as the A side, and stator core 3 and winding 5 are made as the B side, and the A side is powered by U1, and the B side is by U ₂Power supply:

＝U ₁sinw ₀t

＝U ₁sin（w ₀t＋θ）

They produce rotating magnetic field in separately stator and the air gap between the rotor, act on rotor winding 9.With the simplest mode action principle is described, the parameters such as air gap, voltage and winding coil of promptly getting two groups of stator cores are identical, be the phase place difference of voltage supplied, it is E1 and E2 that both sides produce electromotive force, obtains according to the above-mentioned equivalent electric circuit of magnetic potential transformation calculations:

The rotor circuit of these suitable two alternating current asynchronous squirrel-cage motors is cascaded, and thinks that temporarily both sides all are in motoring.

As mentioned above, work as A, when parameters such as B both sides stator core, coil, air gap, voltage magnitude are identical, then

, but phase place will be similar to poor θ angle, the i.e. phase angle of power supply.

If during imagination θ=180 °, then , do not have electric current in the rotor this moment.

If during imagination θ=0 °, then

This moment, suitable two coaxial asynchronous squirrel-cage motors changed the θ value, by following formula:

To cause as can be known

Change, and then cause electric current in the rotor winding Change.

Because two groups of stator winding of motor are respectively by external voltage power supply separately, the relation of load current I2 no longer is simple relevant with reactance and resistance value in the rotor loop, but the current conversion relation is still by the magnetic potential relation

, rotor current is relevant with the amplitude and the phase place of both sides electromotive force simultaneously, thereby

Phase place with

Or

Between angle may be at this moment greater than 90

Will occur

Value greater than

The situation of value, this side motor promptly moves opposite side in the generator mode and provide electric energy to generator one side simultaneously except that supplying with the rotating shaft output mechanical power at this moment, the operation principle of this generator both had been different from synchronous generator, be different from asynchronous generator again, can be referred to as to exchange excitation synchronous generator.

This machine is that with the difference of general synchronous generator it is by f ₁=Sf ₀AC power excitatory to rotor, produce n1=60(f at rotor surface ₀-f ₁) rotating magnetic field, this moment rotor with n ₀-n ₁Rotating speed operation, the real space rotating speed in magnetic field is n ₀, be the same leg speed of power supply, the synchronous speed of this machine depends on the frequency of exciting curent frequency and power supply simultaneously, except that armature reaction and synchronous machine have different, the characteristic of this machine and synchronous machine are very approaching.

This machine is with the difference of general asynchronous generator: the exciting curent of generator one side is provided by opposite side.

The interchange excitation synchronous generator of this machine has three kinds of operating states, phase angle θ is depended in the division of state, as previously mentioned, and when phase angle θ changes to 0 ° by 180 °, motor is that the B side becomes electric motor state by the generator state, exists certain special state in this period to be:

1 0=θ ₀The time, the A side direction rotating shaft of motor at this moment provides rotation speed n ₁Mechanical energy, providing frequency to the B of motor side again is f ₁Exciting curent, motor B side did not provide or absorbed active power to electrical network this moment, and provided or absorbing reactive power to electrical network, the B side of motor is as synchronous compensator usefulness, θ ₀Be referred to as the critical phase parallactic angle.

2. θ＜θ ₀The time, it is n that the A side direction rotating shaft of motor provides rotating speed ₁Mechanical energy P ₁, providing the interchange exciting curent to the B side simultaneously, the B side then provides P to rotating shaft ₂Mechanical energy, this moment, motor B side was moved as asynchronous interchange excited motor mode.

3. θ＞θ ₀＞0 o'clock, it was n that the A side direction rotating shaft of motor provides rotating speed ₁Mechanical output, simultaneously providing frequency to the B side is f ₁AC power, B side rotating speed is n ₁To electrical network feedback frequency of supply is f ₀This moment, the A side of motor was a motor, was again ac frequency convertor, and the B side of motor then is a generator.

By above-mentioned Working state analysis as can be known, the utility model has the conversion process of motor power to be: is P if establish motor A side from the energy that electrical network absorbs ₁, it is P that the B side feeds back to energy electrical network or that absorb from electrical network ₂, this motor is P from the gross energy that electrical network absorbs.

Then θ is by 180 ° of trend θ ₀The time, P ₁Increase, to the energy P of electrical network output ₂Reduce, P increases, and θ tended to P at 0 o'clock by θ 0 ₁Increase, from the energy P of electrical network absorption ₂Increase, P increases, and under the constant condition of moment, the size of output energy has determined to make this motor reach the purpose of speed governing by the height of rotating speed.

Regulate the θ angle and be actually the power angle of adjusting motor, no matter synchronous machine or asynchronous machine, power angle has determined the power output of motor, power angle is the generator state greater than zero the time, power angle is an electric motor state less than zero the time, because the utility model motor has the frequency conversion characteristic, so the output of power will depend on rotating speed, rather than frequency.

The method of regulating the θ angle has two kinds, and a kind of is automatically controlled, inserts a phase shifting transformer between B side stator winding and power supply.The 2nd, on B side stator, add a machinery rotation mechanism, this method can directly be regulated machine motor, has not only saved trouble but also can reduce the cost of whole governing system.

Claims

1, a kind of cage ac governor motor having double stator double magnetic loop, it is included in rotor core and winding [9] thereof is housed on the support [1], it is characterized in that in support [1], being equipped with respectively two groups of independently stator core [2] and [3], on stator core [2], be embedded with three-phase stator winding [4], be embedded with three-phase stator winding [5] on stator core [3], rotor core and winding thereof [9] intert among stator core [2] and [3].

2, according to the described ac adjustable speed motor of claim 1, it is characterized in that rotor core and winding thereof ［ 9 ］ are that two sections independently corresponding respectively two groups of independently stator core ［ 2 ］ and ［ 3 ］ of rotor core ［ 8 ］ and ［ 7 ］ are housed in rotating shaft ［ 6 ］, two sections independently rotor core ［ 8 ］ and ［ 7 ］ go up setting-in one group rotor winding ［ 9 ］, constitute two groups of magnetic loops and act on simultaneously on the rotor winding.