Characteristics Of Asynchronous Motors

1. Small and lightweight.

2. It is easy to realize high-speed rotation with a speed exceeding 10 000r/min.

3. High operating efficiency at high speed and low torque.

4. High torque at low speed and wide speed control range.

5. High reliability (solid).

6. Low manufacturing cost.

7. Simplification of the control device.

The basic feature of an asynchronous motor is that the rotor winding does not need to be connected to other power sources, and its stator current is directly taken from the AC power system; compared with other motors, the asynchronous motor has a simple structure, is convenient to manufacture, use and maintain, and has high operational reliability. Light weight and low cost. Taking a three-phase asynchronous motor as an example, compared with a DC motor with the same power and speed, the weight of the former is only half of the latter, and the cost is only one-third. Asynchronous motors are also easy to derive various series of products according to the requirements of different environmental conditions.

It also has a load characteristic of close to constant speed, which can meet the requirements of most industrial and agricultural production machinery. Its limitation is that its speed has a fixed slip with the synchronous speed of its rotating magnetic field (see asynchronous motor), so the speed regulation performance is poor, and it is required to have a wider range of smooth speed regulation. , windlass, large machine tools, etc.), not as economical and convenient as DC motors. In addition, when the asynchronous motor is running, it draws reactive power from the power system for excitation, which will cause the power factor of the power system to deteriorate. Therefore, in high-power, low-speed occasions (such as drag ball mills, compressors, etc.), it is not as reasonable to use a synchronous motor.

Due to the large production volume and wide application of asynchronous motors, it is required that they must have various varieties, specifications and various mechanical matching. Therefore, the design and production of asynchronous motors should pay special attention to standardization, serialization and generalization. Among all kinds of series products, the three-phase asynchronous motor series with the largest output and the most widely used is the basic series; in addition, there are several derivative series (series derived from the basic series by making some changes), special series (for special needs designed series with special structure).