SOLID-STATE TRANSFORMER IN ISOLATED BIDIRECTIONAL DC/DC CONVERTER EXTENDED UNDER PHASE SHIFT VIRTUAL CURRENT CONTROL STRATEGY|固态变压器中隔离双向 DC/DC 变换器扩展移相下虚拟电流控制策略

In this paper，a virtual current control strategy under extended phase shift is proposed，which focuses on the isolated bidirectional DC/DC converter of solid-state transformer. By analyzing the phase shift relationship of the post-stage converter under the extended phase shift transmission power，the optimal solution of the minimum current stress is obtained to improve the transmission efficiency of the converter and reduce the device loss. At the same time，the virtual current control idea is used to estimate the transmission power online to improve the dynamic response performance of the system and reduce the use of current sensors. Finally，the experimental comparison between the virtual current control and the extended phase shift control under the extended phase shift is carried out. It is verified that the virtual current control strategy under the extended phase shift has the advantages of reducing the current stress and significantly improving the dynamic response of the converter.