Startup mode of single-phase asynchronous motor
Because the output power is small motor, rotor general single-phase asynchronous motor are used the cage rotor, the stator has a set of working winding, called the primary winding, it is in the air gap of motor, can produce positive, negative alternatingpulsating magnetic field, can produce a rotating magnetic field, therefore, will cannot generate starting torque. In order to make the motor air gap can produce a rotating magnetic field, also need to have a set of auxiliary winding, called the secondary winding, the secondary winding and the main winding and the magnetic field generated by the magnetic field in air gap in the synthesis of AC motor to produce a rotating magnetic field, the motor turn to produce torque, therefore, the rotor of the electric machine can automatically rotate.
Capacitor start type
It with a resistance start motor is basically the same, in the stator is also the main phase, vice into 90 electrical degrees of the two sets of winding. The secondary winding and an external capacitor centrifugal switch, and connected with the main winding together, and access to power, in synchronous speed of 75% ~ 80%, the subsidiary winding is cut away, become a single-phase motor. The motor power is 120W ~ 750W.
Shaded pole type
It is a kind of asynchronous motor has the advantages of simple structure, the general use of salient pole stator, the main winding is a concentrated winding, and pair ofphase winding is a single turn short-circuit ring, known as the cover and secondary coils. The poor performance of the motor, but because the firm structure, cheap price,so the production of this motor is great, but the output power is generally not more than 20W.
Resistance starting type
The stator is embedded with a main winding and secondary phase winding, twowinding and the axis in the space into 90 electrical degrees. The subsidiary winding is generally a series of external resistance after centrifugation at the beginning, with the main winding and connected together, and access to power. When the motor is started to speed reaches the synchronous speed of 75% ~ 80%, the centrifuge is opened, the centrifugal switch piece contact power.
Single-phase capacitor start and run asynchronous motor
The motor in the secondary phase windings in access of two capacitors, wherein acapacitor through a centrifugal open
Off, cut off the power supply in the start after; another is always involved in the secondary winding of the work. The two capacitor, a starting capacitor capacity, andthe capacity of small capacitance. The single-phase capacitor starting and running ofmotor, the integrated capacitor start single-phase capacitor running motor andadvantages, so the motor has better starting performance and operatingperformance, in the same frame size, power can be increased by 1 ~ 2 levels of capacity, power can reach 1.5 ~ 2.2kW.
Capacitor running type
The stator winding of the motor is also two sets of windings, and the structure isessentially the same, motor running capacitor run motor technical indicators thanother forms of better before operation. Although there are running performance is better, but the starting performance is poor, that is, the starting torque is low, and themotor capacity is more big, the ratio of starting torque and rated torque is small.Therefore, capacitor start motor capacity do not, generally less than 180W within thescope of.
