摘要
基于下垂调节机制的孤立微电网分层控制体系中,底层控制存在电压调节性能和功率分配精度的固有矛盾,在组网分布式电源(distributed generation,DG)运行点变化时易造成母线电压频率、幅值的突变,需要二层控制在更长的时间尺度下对其进行补偿和修正,这将不利于系统的稳定运行。因此,该文提出一种新型的微电网分层控制体系:一层控制采用分散控制的方法,在系统稳态(如线路阻抗不匹配)或动态(如负荷突变、DG投切)情况下,能够同时满足电压调节质量和功率分配精度。引入权重系数以协调各台DG所承担的负荷比例,该权重系数可由二层控制通过分布式的方式计算生成,并且权重系数可在线调节,权重系数的改变并不影响系统电压稳定。所提分层控制动态响应迅速,有利于实现孤立微电网的功率灵活调控和稳定运行。理论分析和硬件在环实验结果均说明了该控制策略的可行性和有效性。
For the droop-based hierarchical control architecture, the primary control has the inherent tradeoff between superior voltage regulation and power sharing accuracy, frequency and amplitude deviation inevitably appears when deals with the operation point variation of the grid-forming distributed generations (DGs). Although the secondary control is commonly installed to avoid these problems in a relatively long time scale, which significantly affects the system stability. This paper proposed a novel hierarchical control architecture: a decentralized primary control was designed for achieving voltage regulation and accurate power sharing simultaneously in both steady-state (e.g., line impedance mismatch) and transient-state (e.g., loads variation, DG plug in/off). Meanwhile, a weight coefficient was introduced for proportional power sharing performance, which could be distributively calculated by the secondary control. Furthermore, the weight coefficient can be changed on-line and has no effect on the voltage regulation. Thus stable and flexible operation of the micro-grid can be ensured. Theoretical analysis and hardware-in-the-loop simulation results verified the effectiveness of the proposed approach.
作者
黄鑫
汪可友
李国杰
张征
HUANG Xin;WANG Keyou;LI Guojie;ZHANG Zheng(Key Laboratory of Control of Power Transmission and Conversion,Ministry of Education,Shanghai Jiao Tong University,Minhang District,Shanghai 200240,China;State Grid Shanghai Electric Power Company,Pudong District,Shanghai 200122,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2019年第13期3766-3775,共10页
Proceedings of the CSEE
基金
国家自然科学基金项目(51877133)
国家电网公司科技项目(52094017000Z)~~
关键词
孤立微电网
并联组网DG
电压调节
分层控制
负荷功率分配
islanded micro-grid
multi-parallel gridforming DGs
voltage regulation
hierarchical control
load power sharing
