What is the slip rate of an asynchronous motor?

The basic condition for rotor rotation is that the rotating magnetic field generated by the stator cuts the rotor windings, so that the rotor windings obtain electromagnetic torque and rotate. Assuming that the rotational speed of the rotor is equal to the synchronous speed of the rotating magnetic field, i.e., there is no relative motion between the rotor and the rotating magnetic field, then the induced electromotive force of the rotor windings is equal to zero, and therefore the electromagnetic torque is equal to zero, then the motor will stop rotating. This shows that the asynchronous motor can only rotate when the rotor speed is less than the synchronous speed.

The difference between the rotor speed n and the synchronous speed n1 of rotation is called the speed difference, and the slip rate s is the degree of difference between n1 and n, that is.

The rated speed is 1442r min

Slip rate: 1> find the pole pair:

P 60F N 60 50 1442 2 (pair) 2 > synchronous speed:

N1 60F P 60 50 2 1500***3 > Slip Rate:

s＝(n1－n)/n1×100％＝(1500－1442)/1500×100％≈

The speed of the three-phase asynchronous motor refers to the speed of its rotor n, which is the rotating magnetic field (also known as synchronous magnetic field) generated after the three-phase alternating current is passed into the stator winding, and its speed is called synchronous speed is always lower than n1 (this is the origin of "asynchronous"), (n1-n) is called slip. The ratio of slip to synchronous speed is called slip rate s.

s=（n1-n）/n1

When the rotational speed n is lower than the synchronous rotational speed n1, that is, (n1-n) 0, the rotor conductor can cut the rotating magnetic field to generate an induced current, and this induced current can only generate electromagnetic torque and rotate under the action of the rotating magnetic field. Therefore, when the motor is in the electric working state, the slip rate s should be greater than zero and less than 1（0≤s≤1）。

The slip rate of the asynchronous motor, also known as the slip rate (slip), refers to the electric potential induced in the generator winding and the current generated in the generator winding due to the rotation of the rotating parts at the rated working voltage and frequency, and this current will generate electromagnetic force on the rotating parts to push the rotating parts to rotate. However, due to losses such as mechanical friction and air resistance, it is not possible to achieve a synchronous speed at the actual rotational speed. Due to the hailstorm, there is a relative speed difference between the magnetic field formed by the transistor and the magnetic field formed by the voltage of the three-phase AC power supply when the rotating parts rotate, which produces the slippage phenomenon of the motor.

The slip rate of the asynchronous motor refers to the relative deviation between the actual speed of the motor and the synchronous speed. Cracked potatoes are often expressed as percentages or decimals.

In the normal working process of the motor, the smaller the slip rate, the higher the efficiency of the motor and the greater the output power of the motor. When designing and selecting a motor, factors such as load size, starting mode, operating conditions, and protection policies also need to be considered to determine the appropriate slip rate range and the efficiency of the motor.

The slip rate of an asynchronous motor refers to the difference between the rotor speed and the synchronous speed of the rotating magnetic field during operation. The asynchronous electric machine is a rotating magnetic field that induces an electromotive force in the stator winding, which generates an electric current in the rotor from the fiber, and then generates torque to drive the load. When the load torque of the motor increases, the rotational speed of the rotor decreases slightly, which leads to the difference between the rotational speed and the synchronous speed of the rotating magnetic field.

The slip rate is the relative difference between the rotor speed and the rotational magnetic field synchronization velocity, usually expressed as a percentage. The greater the slip rate, the less efficient the motor will be, as more energy is used to generate torque rather than being mechanically converted into output power.

The asynchronous motor is a commonly used AC motor, and its working principle is to use the relatively wide collision motion of the rotor and the rotating magnetic field to generate induced electromotive force, so as to achieve rotation. However, due to the small resistance of the rotor, when the motor is started, the rotor is always at rest and cannot generate induced electromotive force, so it cannot rotate. Therefore, when the asynchronous motor is started, it is necessary to use other means to enable the rotor to generate induced electromotive force and rotate synchronously with the rotating magnetic field.

When the asynchronous motor starts, a power supply is applied to the given sub-windings, which generates a rotating magnetic field. Since the rotor is stationary, there is no magnetic flux inside the flux coil where its windings are located, and the induced electromotive force cannot be generated. However, if a bias voltage is added to the rotor windings to produce a certain current, a certain magnetic flux can be generated in the magnetic field, thereby generating an induced electromotive force, which will cause the current on the rotor to change, and finally the rotor will start to run.

This bias voltage is called the "slip voltage", and the slip rate of the asynchronous motor is the ratio of the slip voltage to the voltage of the main magnetic field.

Therefore, the asynchronous motor must have a slip rate, otherwise the rotor will not be able to generate induced electromotive force, and the rotating magnetic field and the rotation speed of the rotor cannot be synchronized and cannot work normally. At the same time, the slip rate of the asynchronous motor also directly affects the performance, efficiency and stability of the motor.