摘要
传统无互联线微源"功率-电压-电流"三环下垂控制方法在微网系统中受到广泛关注,但其功率分配效果受线路阻感比的影响较为严重,文章分析了两种现有解决方案:利用参数调节使微源等效输出阻抗为感性的方法,其调节能力有限,优化效果不佳;利用虚拟阻抗串联改变微源输出阻抗的方法能大范围调节微源等效输出阻抗,但孤岛模式下微源输出端电压会出现明显跌落。为此本文在已有控制方法基础上,提出一种改进微源虚拟阻抗下垂控制策略,将虚拟阻抗等效为虚拟同步发电机电抗,利用虚拟阻抗压降实现微源输出电压的下垂特性,减小了微源的电压跌落。该策略无Q-V下垂控制外环,控制简单。最后通过仿真以及微源并联实验,对改进前后控制方法的性能进行了对比,证明了所提出方法的有效性。
The conventional microsource wireless droop control base on“power-voltage-current”close loop is widely used. The power sharing performance of this method is significantly affected by the resistive line impedance. This paper analyzes the effectiveness of two existing solutions： the adjustment method by choosing proper control parameters has limited regulating range, which means a poor performance; the virtual impedance control method has a wide range. But it has the problem of voltage sag, this paper provides an improved method with no Q-V power close loop. This method simulates the virtual impedance as the virtual synchronous generator inductance; uses the virtual impedance voltage to realize the microsource Q-V voltage droop characteristic, which can save the microsource voltage sag amplitude. Finally, simulation results and experimental results on the parallel inverter are provided to prove the performance of this new control method.
出处
《电工技术学报》
EI
CSCD
北大核心
2014年第2期145-152,184,共9页
Transactions of China Electrotechnical Society
基金
国家高技术研究发展计划(863计划)资助项目(2011AA05A306)
关键词
微网
分布式电源
下垂控制
虚拟阻抗
虚拟同步发电机
Microgrid
distributed source
droop control
virtual inductance
virtual synchronous generator
