Development Of Controlling System For Submerged Arc Furnace Of Low Voltage Reactive Compensation

The Submerged Arc Furnace has low power factor,but reactive power is high.That let to decrease of efficiency for power supply and affected the economic benefit.Contraposingthis High energy-consuming equipment,Development of automatic controlling system for low-voltage reactive compensation based on PLC and MCGS touch screen.This system can achieve the automatic control of Reactive Compensation on the situation, improve transformer output power,improve electrode potential position and the product quality was assured.The subject was elaborated low voltage reactive power compensation principle.Then it compares the advantages and disadvantages of the existing reactive power compensation devices.Finally,developed a test control system of low voltage reactive power compensation basis on submerged arc furnace itself situation, proposed a throw-cut of the capacitor method for raise capacitor life span.This system is comprised of two designed parts, such as the MCGS touch-screen upper computer system and PLC lower computer system,the transformer primary side power network data collection come from PDM,and the secondary distribution network data collection come from intelligent voltmeter,PLC using RS485bus for collected these data.Using these data,PLC can throw-cut capacitor by automatic control policy.These also transmit for HIM by using RS232.The MCGS HIM can display the primary side power and the secondary distribution network data.At same time,PLC will loading automatic control system real-timely, setting parameters and recording the task data.PLC also can monitoring cooling water temperature of the copper pipe wire based on RS485bus,if the temperature is too high, the capacitor will cut in turn and trigger off emergency situation for operation staff.In order to solve reactive compensation system insufficient,the capacitor can check in or out by cyclically policy for raise capacitor life span;According to the different material properties and product design three throw-cut policy,it can adjust parameters reasonable and raise equipment life span;Using RS232、RS485at link layer, it can solved the equipment caused by ac earth damage effectively.At present,this system apply to many company,such as sichuan wenchuan calcium carbide refinery, wenshan in yunnan, henan and so on. The results show that this controlling system enhancing power factor, balance three phases power and increase production quantity.Enterprises will save money nearly one million each year.