Research On High-frequency Parallel Resonant Inverter Power Supply

The research object of this topic is high frequency induction heating powersupply. Based on the development of induction heating power supply and its currentsituation in home and abroad, two kinds of resonant mode that applied to inductionheating power supply is analyzed respectively. According to the need of the topic,parallel resonance is chosen as the topology structure of the high frequency of thehigh frequency induction heating power supply. Then there is a brief introduction ofthe two kinds of working mode, i.e, voltage mode and the current mode. And throughcomparing, current mode is more proper for this topic. In addition, the control chip isused as the current model control chip and harmonic compensation techniques arealso modified on account of the actual need.Besides, there is an analysis of the working state of parallel resonant invertercircuit. Taking capacitive, resistive and inductive into consideration, the lose ofcapacitive turn out to be the best one. In the following part, the calculation andselection of the components of the main circuit are introduced. Moreover, concretecalculation and selection of the components, say, auxiliary power, matchingtransformer, current transformer, resonant inductance, are also given. In this project,the output power of the constant current source is3kW. In order to meet therequirements, the UC3846chip is being selected and based on which the synchronousend is designed, which realizes the synchronization control and frequency trackingsuccessfully. By analyzing the sweep circuit, the soft start is carried out.The final parts present the schematic and PCB layout drawing of the main circuitas well as the drive circuit. In the experiment, part of the actual waveforms areobtained. Seen from the final result, each part works perfectly. Finally completed thewhole machine commissioning. Confirmed by the experimental requirements, theproject has met the expected requirements.