双端柔性直流系统无通信时的改进直流电压裕度控制

摘要

In order to solve DC voltage control problem of two-terminal VSC-HVDC system without communication,on the basis of detailed analysis of existing control modes,an improved DC voltage margin control strategy is proposed in this paper.The proposed controller realizes the exchange of different control modes before PI controller by constructing an error function and weigh coefficient of quadratic function.Compared with traditional DC voltage margin control priciple,the proposed strategy can simplify the controller structure,and meanwhile it can greatly reduce the limit level of DC voltage during fault-ride-through and power reversal.Simulation results prove the effectiveness of the proposed method.%为了解决双端柔性直流输电系统之间无通信时的直流电压控制问题,在详细分析现有控制方式存在问题的基础上,提出了一种改进的直流电压裕度控制策略.所提控制器通过构造误差函数和二次函数权衡系数在PI控制器之前实现不同控制方式的切换.相比于传统的电压裕度控制原理,该策略在简化控制器结构的同时,能够大大降低故障穿越期间和潮流翻转时直流电压的越限水平.仿真结果表明了本文所提方法的有效性.