文档介绍：摘要
随着变频调速技术的应用日益广泛,应用水平的不断提高,对变频调速控制系统的精度要求也越来越高。目前,许多变频调速装置属于开环控制方式,不能满足较高精度的要求。为提高调速系统的精度,一般都需要进行闭环控制。交流异步电机因其价格低廉,经久耐用,易于维修,适合在恶劣的环境中使用等优点已得到广泛的应用。但交流电机的数学模型和运算较为复杂,其控制特性会受对象内部参数变化的影响,因而用固定的调节器去控制时,往往难以得到较理想的静动态特性。
采取可靠的PLC和变频器控制交流异步电机方法,把变频器V/F控制方式引入到控制系统中,提高了系统的静动态特性。本文结合异步电动机速度闭环控制,提出了一种基于PLC和变频器共同控制实现方法。首先对控制变频调速系统进行总体设计,然后对PLC、变频器与上位机通信程序设计。在此基础上,论述了系统如何安装,调试及系统设备维护等问题。所开发的系统将PLC与变频器相结合,克服了传统的调节器超调大的缺点,充分发挥了PLC控制灵活、编程方便、适应性强的优点,提高了控制的精确度。
实验结果表明,该系统能对电机转速实现精确控制,实用性强,具有一定的推广价值。
关键词:电动机;PLC;变频器。
Abstract
With the increasing applications of variable frequency speed control technology ,the ac
curacy of variable frequency speed control system is required higher than ever . At present, many variable frequency speed control system general require closed loop -onous control moors have been widely used due to their cheep price, being easy to maintain and suitable for use in harsh environments. However, the asynchronous motors models are plex , and its control identity will be subject to the impact of change in internal paraments paraments,thus it is often difficult to obtain better conditions dynamic character by using fixed regulator to control.
Hence a speed control system with PLC based on control is provited. In this paper , a control methed with V/F of inverter applied to the system PLC is present and the control alg-orithm to be realized with PLC is given according to conditions of variable frequency speed. we firstly reseach into the design of variable frequency speed control system, and - munication between PLC puter and munication between inventer and PLC are discussed .The system s weakness of traditional regulator, it has advantages flex-ible ,programming convenient,adaptable,increases the accuracy of the system.
The results show the sytem has good performance and applicable value.
Key words:motor,PLC ,Variable frequency speed regulation.
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摘要 I
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