Design Of The Power Supply Unit On The Medium-frequency Induction Heating Furnace Based On Bridge Rectifier

Silicon controlled medium-frequency power supply unit is a kind of semiconductor frequency conversion device to convert the 50Hz power frequency current into a certain frequency current by using silicon controlled rectifier,it cooperates with various types of loads;As a "cleanest" heating method,it has been applied widely with its advantages of high heating efficiency,fast speed,good controllability and being easy to realize automation,such as metal smelting,surface quenching,heating of forge piece and bent pipe,etc.According to the actual process production requirements,calculates the needed heating power of the heating furnace during the modified pitch production process.Considering the modified pitch production characteristics,designs a medium-frequency power supply unit which suitable for the modified pitch production process.This thesis discusses the following researches on the power supply unit of the medium frequency furnace as following:(1)According to the power of the heating furnace during the modified pitch production process and the related parameters of the heating medium,calculate the power of supply unit.(2)On the basis of the heating principle and also the characteristic and technical requirements of the heating medium,determine the structure of the system and the control strategy.(3)The detail design of the hardware circuit based on the system structure which uses anti-jamming and system protection to ensure the system operate reliably and steadily.And also the hardware circuit has meticulous debugging after completed.(4)Analyst the working principles,the function realization of related circuit,the hardware principles of the control loop and the control module and its solution of various circuits which consist of Three-Phase Full-Bridge Controlled Rectifier circuit,Rectifier trigger circuit,invert circuit,the system protection circuit.Analyst the equivalent model and choose the devices parameters of the main circuit in view of the working process of the whole system.(5)Analyst the various problems during the process of design,experiment,debugging and running about the medium-frequency power supply unit.The medium-frequency power supply unit in this thesis has approved to be reliable and stable by the online production which ensures the stable running and the products quality of the system.