一种改进型混合式直流耗能装置

An Improved Hybrid DC Energy Dissipation Valve

混合式直流耗能装置是一种技术经济性较高的抑制远海风电柔直送出系统受端交流故障直流母线过电压的技术方案。为解决典型混合式直流耗能装置投切工作过程中子模块向直流系统反馈能量问题,研究了一种投切过程具备子模块过电压可控自泄放的改进型混合式拓扑方案,分析了拓扑的工作原理,提出了控制逻辑和子模块电压均衡策略,明确了关键参数的设计方法,基于PSCAD仿真模型验证了所提控制策略和设计方法的正确性。最后研制了原理样机,搭建实验平台,验证了所提方案具备工程可实施性。

The hybrid DC energy dissipation valve is a technical and economical solution to suppress overvoltage on the DC bus during AC faults at the receiving end of the offshore wind power flexible direct transmission system.In order to solve the problem of neutron module feedback energy to DC system during switching of a typical hybrid DC energy dissipation valve,an improved hybrid topology scheme with sub-module overvoltage controllable self-bleed during switching is studied.The working principle of the topology is analyzed,the control logic and sub-module voltage equalizing strategy are proposed,and the design methods of key parameters are defined.The correctness of the proposed control strategy and design method is verified by PSCAD simulation model.Finally,the principle prototype is developed and the experimental platform is built to verify that the proposed scheme has engineering implementability.