导　　师： 徐殿国

学科专业： 080804

授予学位： 博士

作　　者： ;

机构地区： 哈尔滨工业大学

摘　　要： 随着风电在电网中比例快速提高，具有随机性和间歇性特点的风电并网将给系统的无功电压稳定运行带来较大影响。2011年以来，中国西北、华北等大规模风电基地发生了多起风电机组连锁脱网事故。初步分析表明这几起大面积风电脱网事故与风电机组的低电压穿越能力、高电压穿越能力以及无功电压控制等密切相关。当前双馈风电机组（Doubly-Fed Induction Generator, DFIG）已成为世界上风电装机的主流机型，也是在系统故障时发生连锁脱网最多的机组类型。为研究机组连锁脱网原因和提出相应措施，本文研究了电网电压跌落下DFIG运行控制与保护技术，主要研究内容包括： 分析表明了在电网不对称电压跌落下提高DFIG控制能力是应对脱网的技术关键。提出了用于快速分离正负序分量的瞬时对称分量计算法，并将其扩展到分离转子中非工频的正负序分量。仿真对比表明大幅提高了不对称电压跌落下的控制响应速度。提出将DFIG电网电压跌落下的控制过程分为四个阶段，并给出了机//网侧变流器不同阶段相应的控制目标和控制策略。提出了以转子功率变化量为网侧控制前馈项的控制策略，实现了机网侧联合统一控制，仿真结果表明显著改善了电压深度跌落下DFIG的控制性能。 研究了电网电压恢复过程中DFIG连锁脱网重要原因。深入分析了电压跌落和恢复过程中的机端电压相角跳变机理及其对矢量定向控制的影响。提出了机端电压相角补偿控制原理，改进了现有的DFIG电压跌落下控制策略：正常运行及Crowbar退出阶段，采用定子磁链定向控制；在Crowbar投入阶段，封闭转子侧变流器的脉冲，网侧变流器保持正常工作；在电网电压恢复阶段采用相角补偿控制。仿真和动模试验结果表明电压恢复阶段，改进的控制策略能够有效抑制转子过电流，� With the increasing share of the wind power in the power system, the impact of its integration is becoming more widespread. Random and intermittence of wind has more and more influence on the stability of power system. Since2011, the cascad-ing disconnection failures of power system caused by disturbance frequently occur in large-scale wind power base of China's North and Northwest. The preliminary analysis shows that the cascading disconnection closely related to low voltage ride through /(LVRT/) and high voltage ride through /(HVRT/) capability of the wind pow-er generation system and its reactive power control system. Based on its merit, doubly-fed induction generator /(DFIG/) has become one of mainstream model of wind-driven generator which connected with grid directly, and also the most com-mon types in all of the cascading disconnection. In order to explore the causes, op-eration and protection technology under the grid voltage dip were proposed in view of the existing problems. The analysis states that improving the control ability of DFIG under the volt-age dip is the key to deal with cascading disconnection. The method of instaneous sequence component to get the positive and negative sequence was improved and expanded to non-power frequency. The simulation result shows that this algorithm is more effective and efficient compared with the traditional method. The imple-mentation is broken down into four phases, and different objectives and strategies are presented during the voltage dip. Base on the rotor power variation, a novel feed forward control strategy is proposed for DIFG. The simulation results show that the proposed strategy can significantly improve control performance and realize unified control of grid side and rotor side converter. The cascading disconnection was revealed in the grid voltage recovering peri-od. The sudden changes of the phase angle and its impact on the vector orientation under grid voltage dip and recover, was deeply analyzed. The phase angle compen-sation theory and

关 键 词： 双馈风电机组 低电压穿越 撬棒 无功控制 相角补偿

领　　域： [电气工程]