LF炉精确配料控制系统的设计

电子秤精度比较高， 但只能解决称量系统静态误差， 若把电子秤与PLC 结合， 用PLC 控制给料设备的启停和给料速度， 即可控制系统的动态精度， 达到精确称量的目的。利用此原理， 使用S7- 300， 设计了LF 炉铁合金微调称量控制系统。该系统配置包括电子秤和PLC， 其电子秤由称重传感器和称重变送器组成，通过PLC 的输出控制变频器的频率以实现精确加料，用WinCC 完成界面设计，以S7- 300 通信模块CP544
与连铸机DCS 系统Net90 通讯， 在上位机VAX 上进行数据处理。
关 键 词 ：PLC； 称量控制； 电子秤
Abstract: Though electronic scales have a higher accuracy, it can only decrease static error. If
electronic scales are combined with PLC to control start and stop, and feeding speed of feeding equipment, the dynamic accuracy of the system would be controlled and the goal for precision weighing would be achieved too. According to this theory, a precision batching control system for the LF furnace is designed with PLC S7-300. The configuration of the control system includes PLC, electronic scales etc. The electronic scale consists of weighing sensor and weighing transmitters. According as the signal output of PLC, the frequency of frequency converter is controlled to realize precision feeding material. The interface is designed with WinCC, The batching control system communicates with the DCS Net90 of continuous casting machine by CP544 intelligent modular unit of S7-300, and then the data is processed in the second computer VAX.
Key Words: PLC; Control of weighing; Electronic scale