摘要
由于微网中线路阻抗以及负荷分布不均等因素的影响,采用同步电压源控制的微网中各分布式电源的无功功率无法按照下垂系数进行均分。该文针对基于同步电压源控制的微电网,提出一种基于不同时间尺度的分层控制策略,在较短时间尺度内,利用增大下垂系数法的一次控制提高功率均分的精度;在较长时间尺度内,利用二次控制调整下垂特性曲线的空载频率和电压,从而提高系统的电压和频率质量。该文提出的控制算法能够在提高功率均分精度的同时,保证系统的电压和频率质量,且适用于各种拓扑结构的微电网。最后,通过PSCAD/EMTDC数字仿真验证了控制策略的有效性。
Due to the effect of line impedance and unequal load distribution, reactive power supplied by distributed power resources （DR） based on synchronous voltage source converter could not be shared according to their droop gains. A novel hierarchical control of micro-grid according to different time scales is proposed in this paper. In short time scale, larger droop gains is adopted to improve power sharing. In larger time scale, the no load frequency and voltage set points of droop characteristics are adjusted, improving the voltage and frequency quality. The proposed hierarchical control can both limit the reactive power sharing errors and improve the power quality, which can be applied in complex microgrid configurations. Finally, the performance of the proposed control strategy is verified by digital time-domain simulation in PSCAD/EMTDC software.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2013年第34期106-114,18,共9页
Proceedings of the CSEE
基金
国家高技术研究发展计划项目(863项目)(2011AA05A106
2011AA05A301)~~
关键词
微电网
同步电压源
无功功率均分
分层控制
下垂系数
microgrid
synchronous voltage sourceconverter
reactive power sharing
hierarchical control
droopgains
