应用于海上风电接入的VSC-HVDC系统主网侧交流故障穿越的新型直流耗能装置拓扑

直流耗能装置用于海上风电系统主网侧交流故障时吸收风场注入的盈余功率。该文将现有直流耗能装置拓扑归纳为集中式和分布式电阻技术路线,并总结其电路结构、工作机理和控制策略。在此基础上,提出一种混合式耗能装置拓扑,它将2种现存的主流拓扑结合,兼具二者优点却避免了各自的缺点。新拓扑具有功率控制精度高、系统扰动小、子模块内部集成电阻功率低和开关器件损耗小等优点。其具有良好的EMI特性,并且子模块内分布式电阻的功耗降低了75%。最后,通过PSCAD/EMTDC仿真对比和RT-LAB实验证明了上述内容的正确性,同时也验证了所提控制策略的有效性。

A Novel DC Chopper Topology for Grid Side Fault Ride Through in VSC-HVDC Based Offshore Wind Power Connection

DC Chopper is widely used in offshore wind power connection to absorb excess power injected by wind farm during grid side network fault. In this paper, the existing DC chopper topologies were classified into two categories and their circuit structures, working principles and control strategies are summarized. On this basis, a novel DC chopper topology was proposed. It can be regarded as a combination of two mainstream topologies and has the advantages of both but avoids their respective shortcomings. In this way, it has the advantages of high power control accuracy, small system disturbance, low power losses in SM integrated resistors and switching devices. The proposed topology achieves good EMI performance and the maximum power dissipation of the distributed resistor in SM is reduced by 75%. Finally, the correctness of the above content and the effectiveness of the proposed control strategies were verified by PSCAD/EMTDC simulation and RT-LAB based real-time control hardware in the loop(HIL) test.