Publish Time: 2022-11-03 Origin: Site
Earlier we discussed DC motors. During the operation of the DC motor, the excitation magnetic field is stationary relative to the stator. For example, a single-phase AC input to a series-excited motor creates a pulsating power twice the grid frequency, resulting in high torque ripple. This only applies to small motors with loose operating conditions. However, if a high-power and high-torque device is required, the disadvantages of DC motors are exposed.
Here is the list
Comparison of AC Motors and DC Motors
AC Motor Overview
What is the meaning of the AC motor stator?
Compared with the DC motor, the AC motor has a relatively simple structure because it does not have a commutator, and it is relatively firm in manufacture, and it is easy to manufacture a motor with high speed, high voltage, high current and large capacity. AC motor power covers a wide range, from a few watts to hundreds of thousands of kilowatts, or even millions of kilowatts. In the early 1980s, the largest steam turbine generator had reached 1.5 million kilowatts. The principle of an AC motor is very different from that of a DC motor. It introduces the concept of rotating magnetic fields. A rotating magnetic field requires at least three phases of current to form. Unless otherwise specified, the three-phase power supply and AC power supply mentioned below refer to the three-phase AC power supply that changes according to the sinusoidal law.
1 The basic structure of an AC motor
An AC motor (Drehfeldmaschine) is defined in German as a motor in which the surrounding air gap magnetic field rotates relative to a stationary stator, which is the literal meaning of the German "Drehfeld" - a rotating magnetic field. Symmetrical three-phase AC systems (Drehstromsystem) are often used to achieve time-invariant torque and power delivery. The stator of an AC motor usually consists of a laminated core and the AC windings of the stator. Due to the periodically changing alternating current in the windings, a constant, same-frequency rotating air-gap magnetic field is generated called synchronous revolutions (Synchrodrehzahl). So inspired. If the mechanical rotation of the rotor matches the rotation of the rotating magnetic field synchronously, it is called a synchronous motor, and if it does not match, it is called an asynchronous motor.
A three-phase electrical sequence refers to their three time-varying sinusoidal voltages, which are 120° apart in time, exactly dividing a cycle into three equal parts. Generally U, V, W. The laminated core (Blechpaket) coated with the motor-specific alloy coating on the stator of the AC motor is permanently welded or glued. Also, to minimise eddy currents, the laminations are made very thin (0.35-0.5mm) and painted for insulation. Grooves (Nuts) and slots (Nutschlitz) are punched in the laminations. In this way a bundle of AC windings can be wound.
Hangzhou New Hengli Electric Machine MFG. Co., Ltd. (Originally Hangzhou Hengli Electric Machine MFG. Co., Ltd.) was founded in 1954. Over 68 years of manufacturing experience in kinds of DC & AC Motors built up the customer-centered product development methodology and do under the special requirements of customers.