A Solid-State High-Voltage RF Oscillator With CLLC-Type Resonant Topology and Its Parameter Optimization

As the voltage driver of megavolt power supply in Dynamitron accelerator, RF oscillator largely determines the whole system performance. A solid-state RF oscillator scheme with four elements resonant network in CLLC configuration was proposed in this article. By analyzing the operation principle of this CLLC resonant topology, three operation modes and the optimization target of resonant network parameters were discussed. The equivalent circuit model of resonant tank was built with taking the transformer parameter into account. In order to achieve optimal design, the impacts of resonant parameters on the system performance were investigated. The results indicate that larger secondary capacitance can improve system performance but may bring undesirable harmonic issue. Increasing inductance ratio of transformer would bring higher voltage output while lowering the power capability. Then, a parameter optimization method is proposed to achieve a high output voltage, while keeping the power loss and resonant current low. The feasible zone under given set of resonant parameters was determined. Finally, a prototype of RF oscillator applied in Dynamitron accelerator was developed, with a voltage of ∼79 kV and a frequency of ∼100 kHz. The influences of resonant parameters on the system performance were also verified through experiments.