针对孤岛不平衡负载下模块化多电平变换器(MMC)串联结构微电网系统中微源输出功率波动,引起的相间功率不平衡及运行不稳定问题,研究了一种基于有功功率修正(Active Power Correction,APC)的相间功率平衡控制策略.基于系统孤岛模式等效电路,对系统输出功率进行了数学建模,并分析了相间功率流动模式.在三相输出电压对称的前提下,根据微源功率及负载功率确定需要修正的功率,设计了环流控制器,对直流环流控制实现相间功率互济.通过仿真验证,该策略能使相间功率自适应动态调节,达到相间功率平衡的目的.
Phase-to-phase Power Balance Control Strategy of MMC Series Micro Grid Based on Active Power Correction
A phase to phase power balance control strategy based on APC is studied for the phase to phase power imbalance and operational instability caused by the microsource output power fluctuation in the MMC series structure microgrid system under islanded unbalanced load.Based on the system islanding mode equivalent circuit,the system output power is modeled mathematical-ly and the inter-phase power flow pattern is analyzed.On the premise of symmetrical three-phase output voltage,the power to be corrected is determined according to the micro-source power and load power,and a circulating current controller is designed to achieve inter-phase power mutualization using control of the DC circulating current.The strategy has been proven to enable adaptive dynamic adjustment of the three-phase power and eventually make the power balance between phases.
island modepower correctionDC circulationpower balance between phases
国家科技期刊平台
NSTL
万方数据
