【摘要】 为简化阀组在线投入的顺控操作流程,特高压柔性直流输电系统要求柔直阀组具备在直流侧短接状态下完成在线投入的能力。首先,阐述基于混合型MMC特高压柔直阀组的在线投入过程,分析过程中的关键技术难点;然后,结合混合型MMC阀组控制特性及直流侧等效回路,对在线投入过程的关键策略进行详细分析,提出基于直流调制度的特高压柔直阀组在线投入策略实现方案,该策略方案在直流侧短接状态下可实现柔直阀组平稳解锁、直流电流快速转移、旁路开关可靠分断以及子模块均压等关键目标;最后,通过实时数字仿真平台试验,验证所提策略具有良好的控制性能。更多还原

【Abstract】 To simplify the sequence control process,voltage source converter based high voltage direct current transmission system requires that VSC valve group has the ability to complete online entry process when direct current( DC) side is on the short-circuit condition. For this requirement,the key points of online entry for voltage source converter based high voltage direct current valve group based on hybrid MMC are described firstly. Secondly,the key strategies of valve group online entry are analyzed by the control characteristics and DC side equivalent circuit of hybrid MMC,and an implemental scheme based on DC modulation degree is proposed. On the short-circuit condition of DC side,control objectives can be realized including smooth converter deblock,fast DC current transfer,reliable bypass switch breaking and effective sub-module voltage balance. Finally,the effecs of valve group online entry strategies are verified by real-time digital simulations.更多还原