计及Crowbar状态改进识别的双馈风电场等值建模方法

故障过程中双馈风机Crowbar投入与不投入的暂态响应特性差异明显，因而在风电场等值中场内机组Crowbar状态是一个良好的机群划分指标。然而，双馈风电场与单台机组间故障特性的差异性，使得现有采用单机模型来识别场内机组Crowbar状态的方法存在识别不准确的问题，从而降低风电场等值建模精度。为此，该文提出一种计及Crowbar状态改进识别的双馈风电场等值建模方法。通过分析风电场故障特性，构建Crowbar状态特征向量；收集风电场各工况下的样本数据，建立基于支持向量机(support vector machine,SVM)的识别模型。在新工况下，依次以Crowbar状态识别结果和输入风速为分群指标对场内机组进行机群划分，从而建立风电场等值模型。仿真算例结果表明，该文提出的基于SVM的Crowbar状态识别方法在各个故障场景下相较于传统方法均有较好的识别效果，所建立的等值模型与详细模型故障暂态特性十分吻合，等值方法合理有效。

An Equivalent Modeling Method of DFIG-based Wind Farm Considering Improved Identification of Crowbar Status

During the fault process,crowbar activated and deactivated DFIG have a significantly different transient response characteristics.The crowbar status of units is a good indicator for cluster division in the wind farm equivalent.However,the fault characteristics between the doubly-fed induction generator(DFIG)based wind farm and a single unit are clearly different,leading to inaccurate identification in existing literature methods by using a single-unit model to determine the crowbar status of the units in the farm,thereby reducing the accuracy of wind farm equivalent modeling.Therefore,this paper proposed an equivalent modeling method of DFIG-based wind farm considering improved identification of crowbar status.By analyzing the fault characteristics of wind farm,the crowbar status feature vector was constructed.And the sample data of wind farm under various conditions were collected to establish the identification model based on support vector machine(SVM).For new conditions,the identification results of crowbar status and the input wind speed were used as the clustering index to divide the units in the field in turn,so as to establish the equivalent model of wind farm.Finally,the simulation results showed that the SVM-based crowbar status judgment method proposed in this paper has higher identification results than the traditional method in various fault scenarios;the established equivalent model and detailed model fault transient characteristics are highly consistent;and the equivalent method is reasonable and effective.