The Methods Of Reliability Analysis And Enhance For IH Electromagnetic Heaters

IH(Induction Heating)electromagnetic induction heating technology is a new energy utilization in the domestic and foreign recently,it has the characteristics of fast heating speed,high heating efficiency and heating material uniformity compared with the traditional heating methods,so IH electromagnetic heating technology has been widely used in electromagnetic oven,electric cooker,electric pressure cooker and other household appliances products.But at the same time,IGBT(Insulated Gate Bipolar Transistor)in the main control circuit of IH electromagnetic heating technology has problems of breakdown failure,switch chip failure,rectifier short-circuit,those problems lower product reliability and have become increasingly prominent,so the paper takes " the methods of reliability analysis and enhance For IH electromagnetic heaters" as a title,carries out reliability analysis research of failure analysis and root cause finding,circuit reliability design review,thermal test and finite element simulation of complete machine and key device,and optimization design technology research,those researches has important theoretical and practical significance to study reliability analysis research and improvement method of device.Based on the typical fault analysis of IH electromagnetic heater market products,the paper carries out key technology researches of the IH electromagnetic heater failure mode analysis,the main control circuit analysis,power analysis,based on the analysis of reliability,the lifting scheme of IH electromagnetic heater reliability is proposed,and the paper verified the feasibility of the lifting scheme.Main works include:(1)It carried out failure mode analysis research of IH electromagnetic heater.on the basis of the introduction and analysis of several commonly used failure analysis methods,the integrated application of failure component analysis and failure tree analysis method is used to analysis and research the main failure mechanism of IH electromagnetic heater,which leading to IH heater failure accounted for the highest incentives--failure component analysis of IGBT failure,it focuses on the study failure reason of IGBT failure,including heat to burn,over-current and over-voltage breakdown burned,morphology characteristics of each failure model and electric characteristics is studied deeply.(2)Review and analysis research of the main control circuit of IH electromagnetic heater.Through the basic topology and function analysis of electromagnetic heater,electromagnetic heater failure,electromagnetic heater operating characteristics,it determines the main control circuit design review,test focus and direction,it realizes the effective planning of circuit testing,and finished key signal test of the main control board in the electromagnetic heater under different load conditions,the correlation analysis between signal test data(circuit inducement)and three kinds of IGBT typical failure characteristics,some fundamental causes of IGBT failure are concluded.(3)The non contact thermal test and contact thermal measurement of IH electromagnetic heater are carried out,as well as the thermal simulation analysis research of IH electromagnetic heater.Through the research,it obtains effects of heat power problem of IH electromagnetic heater,such as the highest temperature point,temperature margin,blocking duct setting and the influence from air duct to the bridge temperature under some conditions.(4)A scheme to enhance the reliability of IH electromagnetic heater is proposed,and the feasibility of the scheme is verified in the new product development.Through the signal test and analysis research of the 2145 type electromagnetic oven circuit,the paper puts forward the improvement scheme of circuit,carry out heat dissipation optimization design of electromagnetic heater,this paper proposes a new air duct structure scheme of X2115 type electromagnetic oven,the flow field and temperature field of the device of the new scheme are obtain through thermal simulation,and it verified the effectiveness of the scheme;finally,by comparing the IGBT components specifications and performance parameters,and the tests of IGBT short-circuit current,conduction loss,turn off loss in short circuit and under the rated conditions,the IGBT selection recommendations is given.The paper use reliability analysis technology of failure analysis and root cause finding of product back part,circuit reliability design and review,thermal power test and finite element simulation of complete machine and key device,and with a certain type of IH electromagnetic heater as the object,it carries out research of product reliability analysis,improvement and validation of effectiveness,those research can provide important theoretical support and engineering application reference for reliability design,evaluation and improvement method of this type product.