电动机转速的调节方法（Method for regulating motor speed）.doc

电动机转速的调节方法（Method for regulating motor speed） Method for regulating motor speed One is a direct current motor, the other is an alternating current motor. The most frequently used AC motor is an asynchronous motor (induction motor), instead of a squirrel cage induction motor. The two types of motors have different speed regulation methods: DC motor speed regulation The direct current motor means that the direct current is sent to the direct current, and the electric energy of the direct current motor is converted into mechanical energy. The first step here is to introduce how to convert AC from mains to dc. Prior to 60s, the generator motor system (F-D) was adopted, which was only possible when the power was supplied by a special generator. The other is the thyristor motor system (SCR-D). The principle of the two systems: 1. DC motor speed control is more convenient, you can by regulating the armature supply voltage, armature series resistance, excitation loop series resistance to achieve. It can be seen that there are three methods for DC motor speed regulation, and the method of regulating the armature supply voltage is easy to realize the requirements of smoothness, stepless, wide range and low loss. Although the performance of DC motor speed control, can be quite satisfied, but because of the complex structure of summer, big inertia, maintenance trouble, not suitable for operation in harsh environments, not easy to realize the large capacity, high pressure, high speed, and the price is expensive. 2. AC motor speed regulation The AC motor is just the opposite. The motor has the advantages of simple structure, little inertia, convenient maintenance, operation in harsh environment, easy realization of large capacity, high voltage, high speed, and low price. From the point of view of energy saving, the speed regulating device of AC motor can be divided into two categories: efficient speed regulating device and low speed governing device. The characteristics of an eff