Study Of High Frequency High Voltage Transformers And Its Application In Repetitive High Magnetic Field System

High frequency high voltage transformers (HFHV transformers) are widely used inCapacitor Charging Power System (CCPS), pulsed high magnetic field system, etc. Thehigh energy density developing trend of power electronic equipment further promotes thecontinuous development of HFHV transformers. However, its development is impeded byloss and distributed parameters. Repetitive pulsed high magnetic field (RPHMF) is appliedin some essential areas, such as neutron diffraction, THz Radiation. As one of RPHMFsystem’ core elements, HFHV transformers greatly influence the characteristics of RPHMFsystem. This thesis focuses on the design procedure of HFHV transformers and topology ofRPHMF system, the main work is concluded as follows:Fe-based nanocrystalline is chosen to be the magnetic core of HFHV transformers, anew design procedure for HFHV transformers is proposed based on the specificcharacteristic of the nanocrystlline. This procedure is guided the actual winding process andcan improve the utilization rate of the core window。The proposed procedure is described indetail, a10kV,20kW,15kHz transformer serving as an example. Some HFHV transformersare fabricated and epoxy-encapsulation and oil encapsulation are tried. Distributedparameters of HFHV transformer is measured based on the selected equivalentmathematical modeling of HFHV transformer. A CCPS is built to test the quality of HFHVtransformer under its true application environment, repetitive charging experiments showthe fabricated HFHV transformer can meet the design requirement and it is reliable andstable to some degree.A new RPHMF system is proposed in this paper, based on capacitors in seriesdischarging, resonant energy feedback and over-damped energy dissipation. There is noreverse voltage on the self-healing metal film energy storage capacitors, benefiting theapplication of high frequency resonant CCPS and high energy density metal film capacitors,also energy feedback is achieved. The components, such as CCPS and magnet, and theoperation process of the RPHMF system are introduced, further, the efficiency andrepetitive frequency of the whole system is analyzed. A RPHMF system equipment with a Bitter magnet as the load is built, experimental process is explained. At last,8T,1.2HzRPHMF is generated, proving the advantages of the proposed RPHMF system, and also thereliability of the above mentioned HFHV transformers in the application of RPHMFsystem.