The Research Of "One Driving Two" Induction Heating Power Supply Based On DSPIC

Induction Heating Technique has been widely applied in the fields such as metal melting, forging, surface heat treatment, solar heat-transparent and brazing. Due to its own characteristics of cleanness, energy saving, high performance, non-pollution.etc, its control technology changes quickly with the quickening pace of industrialization. Focusing on the power and control problems of traditional Induction Heating Technique, the paper introduces a design,"one driving two"half bridges in series Induction Heating Circuit, which has advantages such as low consumption, safety and flexibility. And with DSPIC30F digital chips as control core, the whole system are researched and designed in this article.Firstly, this paper introduces the structure of"one- pull- two"Induction Heating Power Supply, analyses the working principle of Half Bridges Inverter Power Source in Series and the design selection of the related circuit element and describes the power modulation way suit for this control system based on the dates measured in test. This expounding is based on the object of a single furnace body after comparative analysis of several traditional power modulation ways, accord to the power source structure discussed in this paper, take into account of the demand for power under the melting and heat preservation two kinds of situations and giving consideration to problems such as load matching. Secondly, according to the demand, this paper chooses DSPIC30F3010 produced by Mimochip company which has 28 pins as main control chip. It is mainly used in high performance and precision control area. Meanwhile, considering the dynamicity of induction heating load, in order to realize the frequency tracking and complete the real-time control to induction heating load and ensure this system work in resonant condition to reduce the power consumption and get optimal power output, focusing on the problem that traditional phase-locked has disadvantages such as bad stability and not quick enough dynamic response, this paper establishes the model, realizes Software Phase Lock Loop Technique and makes its simulation experiment using high-performance digital chip DSPIC based on the analysis of traditional phase lock loop work principle. This design is based on the algorithm which is bonding of PI control algorithm and gradually approaching algorithm.At last, this paper introduces a driving circuit formed of ULN2003AN, explains the peripheral circuit such as Protection Circuit and Signal Handling Unit and designs a system monitoring interface which has better interaction.