Crowbar技术在双馈风电机组低电压穿越的应用

Application of Crowbar Technology in Double-fed Induction Generators

对双馈风电机组运行及并网技术等方面进行了研究,针对电网电压波动时,有源Crowbar技术在风电并网中的应用进行了深入的分析。通过针对主动式和被动式两种电路结构和控制方式的建模仿真和90 k W双馈电机实验系统,得出主动式Crowbar电路比较适合我国风电并网技术。然后利用理论研究和软件仿真,得出有源Crowbar保护电路的相关参数。研究技术最终应用与东北某风厂,单机3 MW风机并网系统。通过现场结论分析,得出双馈风电机组并网时,采用有源Crowbar保护电路可以解决电网电压波动时造成的电机过电流和变流器直流侧过电压问题,使双馈风电机组完成低电压穿越运行。

This paper discusses DFIG operation and grid connection techniques, and presents a detailed analysis on the application of active Crowbar in wind power grid connection. Modeling and simulation of active/passive circuitry structures and control modes, as well as 90kW double-fed motor experiment show that active Crowbar circuitry is more suitable for wind power grid connection techniques in China. Furthermore, through theoretical research and software simulation, we obtain related parameters of active Crowbar protection circuitry. The techniques are finally applied to a 3 MW per unit wind turbine grid connection system in a wind power plant in Northeast China. As seen from the conclusions drawn on the site, adoption of active Crowbar protection circuitry for DFIG grid connection can solve the problems of motor over-current and over-voltage on the converter DC side in case of grid voltage fluctuations, so that DFIG may perform its LVRT operation.