用于串联型风电转换系统的电流馈电式双有源桥变换器及其电流源侧启动方法

The series-connected offshore wind energy conversion system (WECS) removes the need for bulky and costly offshore substations. In this system, a current-fed bidirectional isolated DC-DC converter such as the hybrid dual active bridge (HDAB), is essential to supply power from the onshore grid to the wind farm’s local load when there is no wind. However, the reverse-blocking bridge arms on the current-source (CS) side of the HDAB remain off if the auxiliary power supply (APS) is unavailable, preventing the WECS from starting when wind turbines are idle. Moreover, a clamp circuit is needed on the CS side to suppress voltage spikes. This paper presents an improved clamp circuit configuration for HDAB, integrating the CS-side APS with the clamp circuit to provide charging path from the CS-side bus to the APS input. Additionally, a CS-side start-up strategy for HDAB is proposed. The proposed method suppresses voltage spikes and make it possible to power up the APS by the CS-side bus, even without a power source on the voltage side. Simulation and experimental results verify the correctness of the proposed method.