The Intermediate Frequency Heating Power Supply Based On Soft Switching And Current Sharing In Parallel

With the development of social economy and induction heating technology,intermediate frequency induction heating power supply has been widely used in metal surface heat treatment processes such as quenching,smelting,welding,etc.due to its clean,efficient and safe features.The expansion of the application range not only brings huge social and economic benefits,but also puts forward higher requirements and brand-new requirements for the development and design of intermediate frequency induction heating power.In order to provide conditions for subsequent research,the hardware of the intermediate frequency induction heating power supply must be designed firstly.This article mainly analyzes and designs the hardware circuit from two parts: the main circuit and the control circuit.Because the main circuit part needs to work in a strong electrical environment,the selection of device parameters is the main content of the design,so parameter calculation is the main content of the main circuit design part.The control circuit part is mainly to realize the closed-loop control and function expansion of the power supply,so the specific circuit design will be completed according to the requirements.Because the intermediate frequency induction heating power supply sometimes needs to work without stopping for a long time,the accumulation of switching losses will continuously increase the IGBT temperature and affect the stable operation of the device.Therefore,this paper introduces soft switching technology to control switching losses.In this part of this article,the generation of soft switching technology and the principle of power consumption control are introduced firstly,and then several existing soft switching control methods are listed and analyzed.Finally,the temperature difference between the leading and lagging bridge arms in the current soft switching control method is analyzed.After improving the soft switching control method,the equal power consumption control of the IGBT during switching is realized.As a new requirement of intermediate frequency induction heating power supply,the realization of current sharing and parallel operation of intermediate frequency induction heating power supply is also one of the research contents of this paper.In this part of the article,the principle of current sharing technology is briefly introduced,and the characteristic droop control method is selected as the control method for the current sharing of the intermediate frequency induction heating power supply.Then,the droop characteristics of the characteristic droop control method are analyzed.After the impedance is introduced,the droop control coefficient is obtained.Finally,by compensating the phase synchronization signal,the current sharing and phase synchronization of multiple power supplies in parallel are achieved.In the research content of this article,the application of soft switching meets the requirements for higher efficiency of the intermediate frequency induction heating power supply,and the realization of current sharing and paralleling of multiple devices is a study to meet the new requirements.Therefore,the research content of this article has certain practical significance.