The Design And Research Of Electro-hydraulic Servo System Used In Mould Oscillation Of Continuous Caster

The hydraulic non-sine oscillation of mould is one of the key techniques of modern high efficiency continuous caster.Some metallurgy equipment manufacturers,take SMS,VAI and Danieli for example,they have been researching the technique of hydraulic nonlinear oscillation of mould for a long time,and they already have many success applications in slab continues caster,billet continues caster and bloom caster.In our country many big iron and steel companies mainly buy continuous caster with the high technology from abroad,put little emphases on the research of the key techniques.The paper is based on the project from a domestic metallurgy company,whose purpose is to research the hydraulic non-sine oscillation of mould,to improve the level of the continuous caster.The paper is focused on the electro-hydraulic control system of non-sine oscillation of mould used on the bloom continuous caster.In the beginning of the paper,the non-sine oscillation of mould is introduced,including several non-sine oscillation curve,which is applied in continuous caster to improve the surface of the bloom.It is a quiet meaningful project,the emphasis of the paper comprises three parts.The first part is specific design of hydraulic servo system which provides power source to drive non-sine oscillation of mould.According the request of the project,through calculation of the hydraulic system,main hydraulic components are selected,for instance,hydraulic pump and electrical motor,hydraulic servo valve,hydraulic cylinder and other components,then and the mathematic model of hydraulic servo system is established,from which transfer function is derived.More than this,the electrical control system is designed and researched in this paper,improved PID control model is used in the control system to meet the control requirement.At last,simulation software AMESim is used to simulate the hydraulic system and electrical control system.Compare with other simulation software,the modeling of AMESim is based on the physical layer,it has a very comprehensive library,including mechanical,hydraulic,electrical and other libraries.The simulation of the system constructed by AMESim reduces the error which is caused by calculation of transfer function,while other simulation software mainly depends on this way in some academic assumption.We can easily get the static and dynamic characteristics of the hydraulic servo system with simulation software AMESim.Because AMESim is almost the same as the actual system,it can provide an exact simulation result through a humanized GUI(graphical user interface).According to the result of simulation,some changes can be used to improve accuracy of mould non-sine oscillation electro-hydraulic control system.