摘要
为提高自治微网系统的容量和可靠性,多台分布式发电(distributed generation,DG)单元多并联运行。各DG输出电压幅值、频率、相位等微小的差异会在各DG间产生较大的环流,使其中的逆变器性能变差或损坏,因此必须对环流加以控制。分析了自治微网中多台DG并联运行时环流产生的原理,提出了用以抑制环流的等电压、等电流、等功率以及混合式4种主从控制策略。根据各DG采用的LCL接口电路,给出了相应的嵌套式逆变器控制结构。以含3台并联运行DG的自治微网为算例,用Matlab/Simulink进行仿真,分析了不同负载情况下的环流抑制效果,验证了上述策略的正确性和可行性。
To enhance the capacity of autonomous microgrid and improve its reliability, multi distributed generation （DG） units are always operating in parallel. The differences of voltage amplitudes, frequencies and phases among DG units will produce biggish circulating currents among DG units, it makes performance of inverters in DG system deteriorated or the inverters damaged, the circulating currents have to be restrained. The principle causing circulating currents in DG system is analyzed while multi DG units are parallel operated, and four master-slave control strategies, namely equal voltage control strategy, equal current control strategy, equal power control strategy and hybrid control strategy, are proposed. Based on interface circuit of LCL output filter adopted by DG units, corresponding control structure of nested voltage source inverter （VSI） is given. An autonomous microgrid consisting of three parallel-operated DG units is simulated by Matlab/Simulink, the effect of constraining circulating currents under different load conditions are analyzed, thus the correctness and feasibility of the proposed four master-slave control strategies are verified.
出处
《电网技术》
EI
CSCD
北大核心
2011年第4期143-148,共6页
Power System Technology
关键词
自治微网
分布式发电
逆变器
环流
主从控制
autonomous microgrid
distributed generation （DG）
inverter
circulating current
master-slave control
