摘要
微电网具有并网运行与离网运行两种运行模式,为保证用电安全及系统稳定性,要求在微电网运行模式切换过程中实现并网/离网平滑切换。针对微电网中储能变流器(PCS)在并网与离网切换时产生的电流冲击与电压波动等问题,提出一种基于逐波限流的并网/离网平滑切换控制策略,通过比较PCS输出电流峰值是否超出限制值进而改变电流内环控制方式,以降低切换时的电流冲击。在离网切换至并网时提出一种相位、频率双闭环同步控制策略,采用频率内环调节器与相位外环调节器实现并网过程中锁定电网相位和频率,实现快速并网,同时降低并网时的电压振荡。最后通过PSIM仿真验证了上述控制方法的可行性,在并网/离网切换时实现了系统电压、电流的平滑过渡。
Grid-connection and off-grid operation are the two operation modes of microgrid.In order to ensure the safety of power application and stability of microgrid operation,it is required to realize the seamless switching between grid-connection and off-grid during the switching of microgrid operation modes.In view of the current shock and voltage fluctuation generated in the grid-connection and off-grid switching of power converter system(PCS)in the microgrid,a seamless switching control strategy based on wave-by-wave current limiting is proposed.In the strategy,the current inner loop control method is changed by judging whether the peak value of the PCS output current exceeds the limit value,so as to reduce the current impact during mode switching.When switching off-grid to grid-connection,a phase and frequency double closed-loop synchronization control strategy is proposed.The frequency inner-loop regulator and phase outer-loop regulator are used to lock the grid phase and frequency during grid-connection,so as to achieve rapid grid-connection and reduce the voltage oscillation.The feasibility of the above-mentioned control method is verified by PSIM(power simulation).The results show that it can realize smooth transition of the PCS voltage and current during the grid-connection and off-grid switching.
作者
陈兆岭
周炼
吴振飞
娄金山
CHEN Zhaoling;ZHOU Lian;WU Zhenfei;LOU Jinshan(School of Electrical and Information Engineering,Jiangsu University,Zhenjiang 212013,China;Jiangsu Zhen’an Power Equipment Co.,Ltd.,Zhenjiang 212100,China)
出处
《现代电子技术》
2022年第7期102-106,共5页
Modern Electronics Technique
基金
江苏省重点研发计划(BE2019009-2)
江苏大学高级人才基金(1291140044)。
