Development Of Novel High Voltage DC Generator Based On Planar Insulated Core Transformer

As a technology-intensive, high yield and high value-added burgeoning industry,irradiation industry is widely used in industry, agriculture, medical science andenvironmental industry in recent decades. High-voltage linear electron accelerator isthe main technological equipment in irradiation industry, and has a booming numberwith the growth of irradiation industry. In recent years the market of low energy (lessthan1MeV) irradiation, such as surface curing, surface sterilization and rubbervulcanization, climbs sharply and promote the development of low-energy electronaccelerators. However, domestic study on low-energy electron accelerators is on earlystage and difficult to stay competitive.Having advantages over other kinds of high-voltage electron accelerators, such assimplicity in structure and high efficiency, insulated core transformer(ICT) isregarded as a suited type of apparatus used in0.1~1MeV energy region. However,ICT has several shortcomings because it operates on a low frequency, such as heavyand bulky volume and high stored energy, which limited its application. Moreover,the structure of ICT makes it difficult to raise its operating frequency.So our research group develops a novel high-voltage DC generator based onswitching power supply and planar transformer, which is called planar insulated coretransformer (PICT). Compared with the other kinds of high-voltage DC generatorusing double circuit and conventional line-frequency transformer, PICT has a lot ofadvantages: compact structure, low stored energy, excellent transient response, highefficiency, good fault tolerance and high reliability, which make it promising to use inDC power supply below1MV.First this paper analyses disadvantages of ICT and confirms the requisite of highoperating frequency, and then introduces the fundamental configuration and operatingprinciple are described. Formulas using to design PICT are derived and parameter isproposed on the basis of marketing research. Self-designed PICT apparatus isinstalled and preliminary experimental results are presented. Emphatically, magnetic leakage flux (MFL) giving rise to the output voltage drop is analyzed in detail boththeoretically and by finite element method (FEM). Showing good consistency withexperimental result, FEM simulation is considered to be practicable in physical designof PICT. To cancel out leakage inductance and improve the voltage uniformity,compensation capacitor is adopted and experimental verification is also presented. Allshows satisfactory results.