基于VMD和主客观赋权的次同步振荡能量主导因素辨识

Identification of Dominant Factors of Sub-synchronous Oscillation Energy Based on VMD and Subjective and Objective Weighting

新型电力系统中次同步振荡能量特性与运行工况、控制参数、外部环境等息息相关,因此基于不同场景下的量测数据进行次同步振荡能量特性提取及主导因素辨识,可以有效解决实际工程中次同步振荡问题。提出一种数据驱动的次同步振荡能量特性影响因素辨识方法。首先,基于变分模态分解(variational mode decomposition, VMD)解决模态混叠问题,从而提取准确的次同步振荡模态;其次,推导基于端口能量的次同步振荡能量函数表达式,利用模态提取结果进行能量函数计算;最后,采用主客观赋权的方法综合考虑主客观权重建立评估模型,辨识次同步振荡能量特性的主导因素。基于PSCAD/EMTDC平台搭建的风电场并网次同步振荡仿真结果验证了所提方法的有效性。

The energy characteristics of sub-synchronous oscillations in new power systems are closely related to operating conditions,control parameters,and the external environment.Therefore,the extraction of the energy characteristics of sub-synchronous oscillations and the identification of the dominant factors based on the measured data under different scenarios can effectively solve the sub-synchronous oscillation problems in practical engineering.In this study,we propose a data-driven method to identify the factors influencing sub-synchronous oscillation energy characteristics.First,it solves the modal mixing problem based on the variational modal decomposition to extract the accurate sub-synchronous oscillation modes;second,it derives the expression of sub-synchronous oscillation energy function based on the port energy and uses the modal extraction results to calculate the energy function;finally,it uses the subjective and objective weighting to establish an evaluation model to identify the dominant factors of sub-synchronous oscillation energy characteristics by considering the subjective and objective weights.The simulation results of the wind farm grid-connected sub-synchronous oscillations built based on the PSCAD/EMTDC platform verified the effectiveness of the proposed method.