摘要
为提高直驱式变速恒频风电系统的故障穿越能力,采用直流侧过压保护(crowbar)电路,使电网电压跌落时风力机能够保持正常运行,故障消除后系统快速恢复至额定输出。基于对几种常用直流侧crowbar方案的分析比较,选择卸荷负载作为crowbar电路,对网侧变换器和卸荷负载的控制原理及其配合进行了详细说明,对采用和不采用crowbar电路时变换器的跌落特性进行了仿真分析和对比。仿真结果显示采用卸荷负载控制简单,容易实现与网侧变换器的配合,可有效增强直驱式风电系统的低电压穿越能力。
To improve fault ride-through capability of direct-drive variable-speed constant of requency（VSCF） wind power system,DC-link crowbar circuit is adopted to make wind turbine keep normal when grid voltage sags and to help the system rapidly recover to rated output after fault clearance. Based on the analysis of several common DC-link crowbar schemes,damp load is selected as crowbar circuit. The control principle and cooperation of grid-side converter and damp load are explained in detail, then the sag performances without crowbar and with crowbar are analyzed and compared by simulation. The results show the control circuit is simple by adopting damp load and can easily cooperate with grid-side converter, which may effectively strengthen the low voltage ride-through capability of direct-drive wind power system.
出处
《电力系统及其自动化学报》
CSCD
北大核心
2008年第3期118-123,共6页
Proceedings of the CSU-EPSA
基金
中国博士后科学基金项目(20060390092)
关键词
变速恒频
直驱式风电系统
电网电压跌落
低电压穿越
CROWBAR
卸荷负载
varible-speed constant-frequency （VSCF）
direct-drive wind power system
grid voltage sags
low voltage ride-through（LVRT）
crowbar circuit
damp load
