摘要
为了探讨大规模新能源与半波长交流输电系统（HWACTS）中并网系统（GCS）的谐振特性，以风电场的典型拓扑结构为基础，结合较精确的半波长输电线路和变压器谐波模型，建立了大规模风电场与半波长交流输电线路并网的拓扑模型及其等效分析电路。运用模态分析方法对并网系统的谐振特性进行研究，分析并网系统各节点的谐振参与因子及其元件的归一化灵敏度值，确定并网系统的谐振中心。最后，考察不同线路长度和逆变器参数变化及运行工况对并网系统谐振特性的影响，总结出不同参数对应的谐振频率范围，并给出不同运行工况相对于理想工况的谐振点频率偏差。仿真结果表明：35kV母线是并网系统的谐振中心，半波长输电线路长度变化对并网系统的谐振影响主要集中在低频（间）谐波。此外，低压等级线路的长度变化、逆变器的网侧电感、滤波电容和外环比例系数以及特高压交流电网的短路容量对并网系统的谐振也有较大的影响。
In order to discuss the resonance characteristics of grid-connected system（GCS） of large-scale new energy and half-wavelength AC transmission system（HWACTS）, combining accurate harmonic models of half-wavelength AC transmission line and transformer, we built a topology model and equivalent circuit of grid-connected of large-scale wind farms and HWACTS based on the typical topological structure of wind farms. Morever, we adopted the modal analysis method to study the resonant characteristics of the system and analyze the resonant participation factor of each node and every element＇s normalized sensitivity of GCS, whose resonance center was also determined. Finally, we summarized the resonant frequency ranges corresponding to the changes of different kinds of line length, inverter parameter, and operation mode by investigating the influences of different parameters on the resonant characteristics of the system, and put forward the relatively ideal operation condition and the frequency deviations of resonance points of different operation modes. The simulation results show that the 35 kV bus is the resonant center of GCS, the resonant effect of the length change of HWTL on GCS is mainly concentrated in the low frequency（inter） harmonics. In addition, the length changes of low voltage level line, the grid-side inductance, the filter capacitor, the outer loop scale coefficient of the inverter, and the short-circuit capacity of UHV AC grid have remarkable influences on the resonance of GCS.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2018年第1期90-98,共9页
High Voltage Engineering
基金
国家电网公司科技项目(SGRI–DL–71–15–012)~~
