Design And Implementation Of Modular High-voltage High-frequency And High-power Power Supply

High-voltage,high-frequency and high-power supply is widely used in electrostatic dedusting,water quality improvement,medical X-ray,CT machine,subway security inspection machine and welding power source and other large-scale equipments.The conversion efficiency can be improved by using LCC resonant soft switch technology,while the power level and output voltage can be improved by using IPOS modular topology.Steady state models have been proposed only for stand-alone LCC converters in previous researches.The operation of the modular LCC resonant converter,however,is far more complex than that of a stand-alone module converter.The hardware parameters of each power supply in modular converter are slightly different,which will make them bear different loads,which leads to the different working state of each module after IPOS connection and the unbalanced output voltage of each module.In order to solve the above problems,the mathematical model and topology of LCC resonant IPOS module power supply are studied in this paper.A.The mathematical model and solving process of LCC resonant IPOS module power supply are given in this paper.The mathematical model takes into account all the operating conditions of the power supply,including no-load,light-load,heavy-load and short-circuit,and takes into account the influence of the variances of parameters such as series resonant inductance,series resonant capacitance,parallel resonant capacitance,transformer ratio and so on.The relationship between the total output voltage of the IPOS modular power supply and the output voltage of each modular converter can be obtained by using this mathematical model.In the model,the critical normalization method of modular converter is used to distinguish different working modes.The calculated results of the mathematical model are in good agreement with the results of the simulation.The mathematical model given in this paper is further simplified in order to facilitate the engineering design.In this paper,a prototype of three-module experiment is developed,the experimental results are in good agreement with the simulation results,and the correctness of the simplified mathematical model is verified.At the same time,the experimental results also show that each module is running in the ZCZVS working state.In addition,the output voltage ripple decreases obviously compared with the single power supply when the staggered control strategy is used in the experiment.B.A self-equalizing IPOS modular topology is proposed in this paper.The operating modes of the topology are analyzed,and a mathematical model is established to illustrate the principle of voltage equalization.The simulation and experimental verification are carried out for parameter difference,input voltage and load mutation.The topology is characterized by the cross-linking of the rectifier module.Even if the parameters of each module are different or the working conditions change abruptly,the uniform pressure can be obtained without using equal voltage control in this topology.A prototype of two-mode block experiment is developed.The new topology is compared with the traditional topology by changing the parallel resonant capacitance and transformer ratio of the two modules.The experimental results verify the effectiveness of the proposed topology.In addition,changing the input voltage and load,the output voltage follows well.