Online Measurement Approach of the Transformer Parasitics for the LCLC Resonant Converter in the Space TWTA Applications

The LCLC resonant converter is universally applied in the space travelling-wave tube amplifiers (TWTA). Normally, the open-loop control is utilized in the LCLC resonant converter, where the switching frequency and duty cycle are set to the exact values to achieve soft switching characteristics. However, since the switching frequency and duty cycle are calculated by the transformer parasitics, it is crucial to measure the real transformer parasitic parameters precisely. The classical way to measure the transformer parasitics is by an impedance analyzer, however, the transformer parasitics under real operating conditions may deviate from the offline measured results. In order to solve the above problem, an online measurement method is proposed in this paper. With this online measurement approach, all the real transformer parasitic values can be easily obtained in a low cost and simple implementation way. The proposed method is validated by the experiments as well.