【摘要】 针对对等结构的微网系统,提出了一种在联网运行模式和孤岛运行模式下平滑切换的控制策略。首先,微网中储能逆变器在两种运行模式下均采用下垂控制方法,孤岛发生时逆变器无需切换控制算法,减小了两种运行模式切换过程中的暂态响应。其次,提出基于分层控制和电压频率恢复控制的微网预同步控制方法,实现了微网系统由孤岛运行模式向联网运行模式的平滑切换。给出了微网逆变器、微网系统二次电压频率恢复控制和预同步控制算法的详细理论分析,最后通过实验验证了所提方法的可行性和有效性。更多还原

【Abstract】 By taking the peer-to-peer structure microgrid as the research object,a seamless transfer control method for primary control and secondary control is proposed.In the primary control part,the microgrid inverters are controlled in droop mode in both microgrid island mode and grid connected mode.The transient response can be reduced since there’s no need to switch the control algorithm during the microgrid mode transfer period.In the secondary control part,agrid synchronization method based on hierarchical control is proposed,which allows droop-controlled inverters to adjust the frequency,phase,and amplitude of their output voltages to synchronize with the grid,realizing smooth transition from islanded mode to grid connected mode.The inverter control algorithm,frequency restoration and pre-synchronization control algorithm are analyzed in detail,experimental test results presented to validate the effectiveness of the proposed method.更多还原