基于模态分析的宽频带振荡区域定位研究

Study on Wide-band Oscillation Region Location Based on Modal Analysis

伴随化石能源的枯竭和我国能源转型战略的推进,新能源发电系统上网电量不断增加。电力系统“双高”特性日益显著,系统运行面临更为复杂的挑战,其中电力电子装置引发的宽频带振荡备受关注。因此,针对新能源系统宽频带振荡产生的机理,提出一种基于模态分析的宽频带振荡区域定位方法,用于新能源系统振荡频率和振荡区域定位。根据逆变器、线路阻抗和电网阻抗等系统参数,建立不同型号逆变器并联系统的高阶导纳矩阵。对矩阵进行等效变换,通过绘制模态阻抗随频率变化的曲线,得到系统可能的谐振频率。通过节点参与因子计算,定位振荡的区域。通过仿真验证,模态分析方法可以实现宽频谐振的精准频率定位和区域定位,可为新能源场站接入评估和事故定位提供依据。

With the depletion of fossil energy and the promotion of China's energy transformation strategy,the power of new energy power generation system is increasing.The"double high"characteristics of power system are becoming more and more obvious,and the operation of the system is facing more complex challenges.Among them,the wide-band oscillation caused by power electronic devices has attracted much attention.A wide-band oscillation region positioning method based on modal analysis was proposed by analyzing the mechanism of broadband oscillation in new energy system,which is used to locate the oscillation frequency and oscillation region of new energy system.According to the system parameters such as inverter,line impedance and grid impedance,the high-order admittance matrices of different types of inverter parallel systems were established.The equivalent transformation of the matrix was carried out,and the possible resonance frequency of the system was obtained by drawing the curve of modal impedance changing with frequency.Through the calculation of node participation factor,the oscillation area was located.The modal analysis method was verified by simulation,which can achieve accurate frequency positioning and regional positioning of broadband resonance,and can provide a basis for access assessment and accident location of new energy stations.