A kind of anti-salient pole permanent magnet synchronous motor
Technical field
The present invention relates to a kind of permagnetic synchronous motor, particularly a kind of anti-salient pole permanent magnet synchronous motor.
Background technology
That permagnetic synchronous motor has is simple in structure, high power density, high efficiency advantage, because the excitation of magneto source is permanent magnet, motor itself simple in structure, the volume less, power density is higher, power factor is high, therefore, in driven by power and wind power generation field, is widely applied.Especially the permagnetic synchronous motor overload capacity that has saliency is strong, applies more extensive.
But, because the direct axis reluctance of the conventional permagnetic synchronous motor with saliency is greater than quadrature-axis reluctance, direct-axis synchronous reactance is less than quadrature axis synchronous reactance, it is negative value at the merit angle while spending that the reluctance torque component is less than 90, the merit angle of maximum electromagnetic torque is greater than 90 degree, and when load running, there is larger demagnetization danger in permanent magnet.In addition, when load running, the quadrature axis magnetic circuit is very saturated, and iron loss is large, and electric efficiency is not high.
Summary of the invention
Technical problem: the objective of the invention is the problem existed for prior art, provide a kind of compact conformation simple, avoid the permagnetic synchronous motor that demagnetization is dangerous, iron loss is little, have anti-saliency.
Technical scheme: for achieving the above object, anti-salient pole permanent magnet synchronous motor of the present invention comprises rotating shaft, be located at the rotor core in rotating shaft, the stator core matched with rotor core, be evenly equipped with a plurality of stator slots on the inner edge of stator core, be equipped with stator winding in a plurality of stator slots, be evenly equipped with a plurality of rotor slots on the outer rim of rotor core, be equipped with rotor conductor in a plurality of rotor slots, evenly be provided with even number in described rotor core and be around rotating shaft the permanent magnet trough that M shape is arranged, permanent magnet trough is positioned in rotor core symmetrical with respect to each rotor straight axis, be in the rotor core between the permanent magnet trough that M shape arranges and offer the triangle ventilation hole along rotor shaft direction, be in the permanent magnet trough that M shape arranges and be equipped with and be the permanent magnet that M shape is arranged.
Described triangle ventilation hole is the isosceles triangle be symmetrically distributed on rotor quadrature axis line, on one side isosceles triangle is triangle ventilation hole base by rotor slot, the side of isosceles triangle is triangle ventilation hole side.
Described to be around rotating shaft permanent magnet trough and the rotor core section between triangle ventilation hole side that M shape arranges be medial septal magnetic magnetic bridge, and the rotor core section between triangle ventilation hole base and rotor slot base is lateral septal magnetic magnetic bridge.
Beneficial effect: owing to having adopted technique scheme, the present invention has offered a triangle ventilation hole at rotor quadrature axis line position, makes quadrature axis synchronous reactance
x qbe less than direct-axis synchronous reactance
x d, motor has the electromagnetic property of anti-salient pole, has avoided the danger of demagnetization, has increased overload capacity and the stability of motor simultaneously.Dig the triangle ventilation hole in rotor quadrature axis iron core due to motor, air permeability is low, so the quadrature axis magnetic circuit reluctance is large, and magnetic circuit is difficult for saturated, has reduced iron loss.Ventilation hole can also facilitate the rotor heat radiation simultaneously, reduces temperature of rotor, the protection permanent magnet.Permanent magnet trough is the arrangement of M shape in addition, and the air gap flux density ripple that can make permanent magnet produce, closer to sine wave, has reduced higher harmonic content effectively, has improved electric efficiency.It is simple in structure, iron loss is little, have practicality widely.
The accompanying drawing explanation
Fig. 1 is the structure chart of anti-salient pole permanent magnet synchronous motor of the present invention.
Fig. 2 is the rotor structure figure of anti-salient pole permanent magnet synchronous motor of the present invention.
Fig. 3 is the power-angle curve figure of conventional salient pole permanent magnet synchronous motor.
Fig. 4 is the power-angle curve figure of anti-salient pole permanent magnet synchronous motor of the present invention.
In figure: the 1-stator core; The 2-stator slot; The 3-stator winding; The 4-rotor core; The 5-rotor slot; The 6-rotor conductor; The 7-permanent magnet trough; The 8-permanent magnet; 9-triangle ventilation hole; The 10-rotating shaft; 41-medial septal magnetic magnetic bridge; 42-lateral septal magnetic magnetic bridge; 71-permanent magnet trough base; 91-triangle ventilation hole base; 92-triangle ventilation hole side; D-rotor straight axis; Q-rotor quadrature axis line.
Embodiment
Below in conjunction with accompanying drawing, one embodiment of the present of invention are further described:
As depicted in figs. 1 and 2, the 4 extremely anti-salient pole permanent magnet synchronous motors of take are example, anti-salient pole permanent magnet synchronous motor comprises stator, rotor and rotating shaft 10, described stator comprises stator core 1, stator core 1 is provided with a plurality of stator slots 2, be equipped with stator winding 3 in each stator slot 2, described rotor comprises the rotor core 4 be located in rotating shaft 10, be evenly equipped with a plurality of rotor slots 5 on the outer rim of rotor core 4, be equipped with rotor conductor 6 in a plurality of rotor slots 5, evenly be provided with even number in described rotor core 4 and be around rotating shaft 10 permanent magnet trough 7 that M shape is arranged, the permanent magnet trough 7 that M shape is arranged as required can be 2, 4, 6 or 8, permanent magnet trough 7 is positioned in rotor core 4 symmetrical with respect to each rotor straight axis d, offer triangle ventilation hole 9 along rotating shaft 10 directions in the rotor core 4 between the permanent magnet trough 7 that is the arrangement of M shape, between the permanent magnet trough 7 that is the arrangement of M shape, each rotor quadrature axis line q position is dug a triangle ventilation hole 9 vertically, be in the permanent magnet trough 7 that M shape arranges and be equipped with and be the permanent magnet 8 that M shape is arranged.Described triangle ventilation hole 9 is for being symmetrically distributed in the isosceles triangle on rotor quadrature axis line q, isosceles triangle be triangle ventilation hole base 91 by rotor slot 5 on one side, close rotor slot 5 bottoms, triangle ventilation hole base 91 and vertically being divided equally by rotor quadrature axis line q; The side of isosceles triangle is triangle ventilation hole side 92.The permanent magnet trough base 71 and the rotor core section between triangle ventilation hole side 92 that are M shape arrangement permanent magnet trough 7 around rotating shaft 10 are medial septal magnetic magnetic bridge 41, and the rotor core section between triangle ventilation hole base 91 and rotor slot 5 bases is lateral septal magnetic magnetic bridge 42.
Operation principle: the electromagnetic torque with permagnetic synchronous motor of saliency
t emby basic torque component
t embwith the reluctance torque component
t asynthetic, its equation is:
Ⅰ
In the formula I,
θit is the merit angle;
t mit is the amplitude of basic torque component;
c tmoment coefficient,
x qquadrature axis synchronous reactance,
x dit is direct-axis synchronous reactance.
As shown in Figure 3, the quadrature-axis reluctance of conventional existing salient pole permanent magnet synchronous motor is less than direct axis reluctance, quadrature axis synchronous reactance
x qbe greater than direct-axis synchronous reactance
x d, therefore, it is negative value at the merit angle while spending that the reluctance torque component is less than 90, the merit angle that maximum electromagnetic torque is corresponding is greater than 90 degree.When motor load operation merit angle is greater than 90 while spending, the d-axis armature reacting field is contrary with rotor permanent magnet 8 magnetic directions, plays demagnetizing effect, the therefore larger demagnetization danger of existence.
As shown in Figure 4, anti-salient pole permanent magnet synchronous motor of the present invention is equipped with a triangle ventilation hole 9 in rotor quadrature axis line q position, and quadrature-axis reluctance is greater than direct axis reluctance, quadrature axis synchronous reactance
x qbe less than direct-axis synchronous reactance
x d, therefore, the reluctance torque component at the merit angle, be less than 90 while spending on the occasion of, the merit angle that maximum electromagnetic torque is corresponding is less than 90 degree.When motor load moves, the d-axis armature reacting field is identical with the rotor permanent magnet magnetic direction, plays the magnetic assist effect, therefore there is no the danger of demagnetization, has increased overload capacity and the stability of motor simultaneously.
In addition, because all there is a triangle ventilation hole 9 rotor quadrature axis line q position, increased the magnetic resistance of quadrature axis magnetic circuit, magnetic circuit is not easy saturated, has reduced iron loss.The existence of ventilation hole simultaneously can facilitate the rotor heat radiation, reduces temperature of rotor, protection permanent magnet 8.
Permanent magnet 8 is larger at the air gap flux density of rotor straight axis d, less away from the air gap flux density of rotor straight axis d, so the air gap flux density ripple that permanent magnet 8 produces reduced higher harmonic content effectively closer to sine wave, has improved electric efficiency.