基于plc控制的异步电动机软起动器的应用（Application of asynchronous motor soft starter based on PLC control）.docVIP

基于plc控制的异步电动机软起动器的应用（Application of asynchronous motor soft starter based on PLC control） ? Application of asynchronous motor soft starter based on PLC control Li Chuanwei? (Weihai Vocational College, 264210) Abstract: This paper introduces the working principle, operation mode, running characteristics and control mode of soft starter, and introduces the application of PLC in soft starting of AC motor in detail Key words: asynchronous motor; soft starter; motor starting characteristic; PLC control CLC number: TM 571.6 + 1; TM 343. + 2, document identification code: B, article number: 1004- 0420 (2008) 06- 0055- 03 0 Introduction In the starting control of AC asynchronous motors, the full voltage is often used There are two ways to activate and start the buck, as the traditional way of starting. But in For some special occasions, are these traditional ways of starting? Little abuse. In recent years, due to the development of frequency conversion and soft start technology, it has been solved There are some difficult problems in motor control, especially the soft start technology It has outstanding function in solving the problem of motor starting of large and medium capacity A new technology for step-down startup. 1, the traditional way of starting and its defects 1.1, the defects of the traditional startup methods A start up to 7 times the starting current of 5~, resulting in motor windings Overheating caused by overheating, accelerated insulation aging; B. The voltage drop in the power supply network is too large, when the voltage is 0.85 U n The normal use of other equipment, especially under voltage protection; C. Energy loss at startup is too large to waste electrical energy, especially when frequent Startup time; D. It has a great impact on the driven equipment and shortens the equipment Service life affecting accuracy; E cause abnormal wear and tear of mechanical transmission parts and speed up the old equipment Shorten life; F contactor and other control equip