DC motors cannot be started directly
2016-09-02 17:49:36 来源: 永磁直流电机_博山直流电机厂-淄博市博山广联电机厂 Hits: 2186 2016-09-02 17:49:36 Source: Permanent magnet DC motor_Boshan DC Motor Factory-Zibo Boshan Guanglian Motor Factory
DC motors cannot be started directly. In what way do we generally start DC motors? Let's take a look at how its machinery starts. 1. Because the armature circuit resistance and inductance of the DC motor are small, and the rotating body has a certain mechanical inertia, when the DC motor is connected to the power, the armature speed and the corresponding back-EMF at the beginning of the startup are small, and the starting current is very Big. Up to 15-20 times the rated current. This current causes disturbances to the power grid, mechanical shock to the unit, and sparks from the commutator. Therefore, direct-closing start is only suitable for motors with a power not greater than 4 kW. 2. There are three ways to start the DC motor: direct-closing start, string resistance start and voltage drop start. 3. In order to limit the starting current, the starting control of DC motors often adopts the method of step-down starting or armature circuit series starting resistance. For example, city trams are often started. In order to simplify equipment, reduce weight, and facilitate operation and maintenance, a string resistance start method is usually used. The above is the starting method of the DC motor. We must carefully read the above content. Mastering the correct starting method is the key.
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