Permanent magnet motor 'tall' mainly reflects in what respect?
form a complete set of necessary and effect analysis of permanent magnet motor
equipment form a complete set of permanent magnet motor power core change if that is not simple, common power supply for controllable power supply must be updated accordingly, and permanent magnet motor ontology together form the system of permanent magnet motor. Compared with the conventional motor system, permanent magnet motor system by frequency conversion variable pressure power electronic converter, the motor output shaft speed and power can be adjusted wide range smoothing, itself a revolutionary upgrade equipment performance, namely along with the change of the load, adaptive adjustment of equipment and economic operation, energy-saving effect is very significant.
the permanent magnet motor with ordinary motor
ordinary motor differentiation of two kinds of step motor and synchronous motor. 70% ~ 80% of the equipment using asynchronous motor, a handful of big torque and low speed device using the synchronous motor.
'the origin of the asynchronous and synchronous
ac motor speed is closely related to the armature rotating magnetic field. Synchronous motor rotor speed and the armature magnetic strictly synchronous rotation, speed constant. And rotational speed asynchronous motor speed is always lower than that of rotating magnetic field, rotor winding closed loop under the effect of rotating magnetic field induced current, rotor current-carrying coil in the magnetic field by the magnetic field of electromagnetic force continues to function, to drive the rotor rotation, so have the asynchronous induction motor and the said.
when the difference between the synchronous motor and induction motor
when synchronous machine, rotor speed and a constant relationship between the grid frequency, n = ns = 60 f/p, which is suitable for power grid frequency, f p for motor logarithm, ns called speed of a rotating magnetic field or synchronous speed. Induction motor slip problems, speed close to synchronous speed, slightly lower than the synchronous speed.
look from the motor structure, the squirrel-cage asynchronous motor rotor or rotor and the stator winding, and for the three-phase symmetric winding. For convex concentrated winding excitation synchronous motor rotor or distributed winding excitation, excitation power supply for dc.
permanent magnet motor
permanent magnet motor points two categories, permanent magnet dc motor and permanent magnet ac motor.
permanent magnet dc motor including permanent magnet motor and permanent magnet brushless dc motor commutator or permanent magnet electronic motor commutator. Permanent magnet ac motor is commonly referred to as permanent magnet synchronous motor, the structure and the permanent magnet brushless dc motor, driving principle and control methods.
the permanent magnet synchronous motor and synchronous motor
working principle of the permanent magnet synchronous motor and synchronous motor is the same, the difference is that: by permanent magnet excitation permanent magnet synchronous motor, no exciting winding, there is no loss of excitation; Synchronous motor for electric field, the field winding loss and fever were often is the weak link of ventilation cooling system.
advantage of permanent magnet synchronous motor
the permanent magnet synchronous motor compared with the synchronous motor and induction motor, there is no electric field and the corresponding loss, permanent magnet rotor is not hot, can choose high electricity load, and small volume, high power density.
as the new type of motor control theory and the rapid development of rare earth permanent magnet materials, permanent magnet synchronous motor to further enhance performance, compared with the ordinary motor, there are many unique advantages.
high efficiency and energy saving. Because of excitation magnetic field is provided by permanent magnet and don't need permanent magnet rotor excitation, efficiency can be as high as above 90%. Compared with asynchronous motor, wide speed range operation with high efficiency, energy saving is obvious. Especially in the low speed running, advantage is more obvious.
low low temperature. No electrical excitation means no heat loss, therefore, permanent magnet motor temperature rise is low in general.
low starting performance is good. Since the start permanent magnet synchronous motor in general, using asynchronous starting way. Work properly when the permanent magnet synchronous motor rotor winding, permanent magnet motor rotor winding can be designed to fully meet the requirements of high starting torque, such as starting torque ratio by 1. Eight times to 2. 5 times or more.
low impact on power grid operation. Asynchronous motor to absorb a large number of reactive current from the power grid, power grid caused by power transmission and transformation system has a large number of reactive current, thus lowered the quality factor of the grid, the increase of power transmission and transformation equipment and power equipment load. At the same time, the reactive current in power grid transmission system consumes part of electricity, power grid operation caused by inefficient, and low efficiency of induction motor, from the situation of the grid to absorb more energy superposition, electric energy loss, power grid load has increased.
in the permanent magnet motor rotor excitation without electricity, the unique advantages of high power factor, help to improve the grid quality factor or no longer need to install compensator in the grid.
low permanent magnet motor has the characteristics of wide range of efficient operation, widely used in the field of new energy vehicles.
small volume, light weight. Super high-performance permanent magnetic material application, makes the permanent magnet motor sharply reduce the volume and weight, and power density at least 1 for ordinary three-phase asynchronous motor. More than 5 times.