基于非对称故障的海上风电接入柔性直流换流站控制策略  

Control Strategy of Offshore Wind Power Connected to Flexible HVDC Converter Station Based on Asymmetric Fault

作　　者：李道洋 杨美娟 吴庆范[2] 宋延涛 范雪峰 LI Dao-yang;YANG Mei-juan;WU Qing-fan;SONG Yan-tao;FAN Xue-feng(Xi'an XJ Power Electronics Technology Co.,Ltd.,Xi'an 710075 China;Xuji Group Corporation,Xuchang 461000 China)

机构地区：[1]西安许继电力电子技术有限公司,陕西西安710075 [2]许继集团有限公司,河南许昌461000

出　　处：《自动化技术与应用》2022年第7期21-25,共5页Techniques of Automation and Applications

基　　金：国家自然科学基金资助项目(5729264);江苏省自然科学基金资助项目(sk277054);广东省科技厅科技项目(2014b0048)。

摘　　要：近年来海上风电场通过柔性直流输电接入大电网的系统方案越来越受到业界重视。传统的柔性直流输电系统在应对非对称故障时均采用将负序电流限制为0的控制策略,然而连接风电孤岛的海上换流站若采用该策略,将无法起到支撑交流电压的作用,从而引起风机脱网。为解决这一问题,文中提出一种基于正负序电压独立控制的孤岛柔性直流换流站控制策略,在非对称故障期间输出部分负序电流以提升故障相的电压,降低风机脱网概率,同时避免桥臂过流导致的换流阀闭锁,实现故障穿越,有一定的参考价值。In recent years,the solutions for offshore wind farms to connect to large power grids through flexible HVDC transmission receive increasing attention from the industry.The traditional HVDC flexible transmission system adopts the control strategy of limiting the negative sequence current to 0 under asymmetric faults.However,if the offshore converter station connected to the wind power island adopts this strategy,it can't play the role of supporting the AC voltage,which causes wind turbines to disconnect from the grid.In order to solve this problem,the article proposes a control strategy for island flexible HVDC converter based on independent control of positive and negative sequence voltages.During an asymmetric fault,part of the negative sequence current is output to increase the voltage of the faulty phase and reduce the probability of wind turbine disconnection.At the same time,it avoids the blocking of the converter valve caused by the bridge arm overcurrent,and realizes the fault ride-through.

关 键 词：海上风电接入 柔性直流输电 非对称故障穿越 控制策略 

分 类 号：TP18[自动化与计算机技术—控制理论与控制工程]