双馈风电机组机电耦合与轴系稳定的分析与辨识  

Analysis and Identification for Electromechanical Coupling and Shaft Stability of Doubly-Fed Induction Generator

作　　者：郝正航[1,2] 余贻鑫[1] 

机构地区：[1]天津大学电力系统仿真控制教育部重点实验室,天津300072 [2]贵州大学电气工程学院,贵阳550003

出　　处：《电工技术学报》2011年第3期134-139,共6页Transactions of China Electrotechnical Society

基　　金：国家重点基础研究发展计划(973计划)资助项目(2004CB217904)

摘　　要：为了研究双馈风电机组的机电解耦条件,在转子电流控制策略中引入了前馈补偿系数。通过对线性化模型的推导,给出了机电解耦条件和机电耦合程度的量化指标。基于线性化模型的分析表明,在一定条件下,前馈补偿将引起电气负阻尼而诱发轴系扭振。还提出自然工况下轴系、电磁模式的在线辨识方案,引入子空间法进行系统辨识和振荡模式提取。算例分析表明,前馈补偿系数不仅决定了机电耦合程度,而且影响轴系稳定性,证实了理论分析的结论。算例还表明文中提出的振荡模式在线辨识法具有良好的精度,可作为机组安全监控的组成部分。In order to investigate the decoupling conditions for doubly-fed induction generator（DFIG）,the coefficient of feed forward compensation is defined for the control strategy of rotor current.Firstly,both conditions of electromechanical decoupling and a quantitative index of coupling are presented by deducing a linear dynamic model of the DFIG.Based on analysis of the linear model,it is shown that feed forward compensation can produce negative electrical damping and result in torsional oscillation of shaft.Then,an on-line identifying scheme for mechanical modes and electrical modes is developed,which employs subspace identification algorithm to extract the dominating modes under the natural operation conditions.Finally,a simulation case illustrates that the coefficient of feed forward compensation influences the degree of electromechanical decoupling as well as stability of shaft system.The case also demonstrates that the proposed on-line identification scheme of oscillation modes,featuring a satisfied precision,can develop a component of security monitor system for DFIG.

关 键 词：电力系统 风力发电 双馈电机 前馈补偿 在线辨识 小扰动稳定 

分 类 号：TM351[电气工程—电机]