摘要
多逆变器并联组网运行时,针对传统下垂控制中一次调频和调压能力有限而导致的频率和电压越限问题,提出了一种具有自愈能力的改进下垂控制策略。该策略通过适当提高空载角频率和空载电压,将逆变器实际输出功率与预期功率的差值通过积分环节来调整下垂系数大小,从而实现频率和电压的自愈。在此基础上,分析了下垂系数对功率分配的影响,通过基准逆变器功率变化信息的共享,按容量比设置积分系数,控制不同逆变器下垂系数大小时刻成比例,实现了频率和电压自愈的同时有功和无功功率在多台不同容量逆变器之间的精确分配。建立了系统小信号建模,通过根轨迹法分析了控制器参数变化时对系统稳定性的影响。最后,通过实验和仿真结果验证了所提策略的可行性和有效性。
When multiple inverters are connected in parallel,in order to solve the problem of frequency and voltage overstepping caused by the limited capacity of primary frequency and voltage regulation in traditional droop control,an improved droop control strategy with self-healing ability was proposed.By properly increasing the no-load frequency and no-load voltage,the difference between the actual output power and the expected power of the inverter was used to adjust the droop coefficient through the integral link,so as to realize the self-healing of frequency and voltage.On this basis,the influence of droop coefficient on power distribution was analyzed.By sharing the power change information of the reference inverter and setting the integral coefficient according to the capacity ratio,the droop coefficient of different inverters was controlled to be proportional at different times,and the precise distribution of active and reactive power among inverters with different capacities was realized while the frequency and voltage self-heal was realized.The small signal modeling of the system was established,and the influence of the controller parameters on the system stability was analyzed by the root locus method.Finally,simulation and experimental results verify the feasibility and effectiveness of the proposed strategy.
作者
刘勇
刘鹏
盘宏斌
阳建
贺生国
雷延科
LIU Yong;LIU Peng;PAN Hongbin;YANG Jian;HE Shengguo;LEI Yanke(College of Information Engineering,Xiangtan University,Xiangtan 411105,Hunan,China;Shenghong Shenzhen Electric Co.,Ltd.,Shenzhen 518000,Guangdong,China)
出处
《电气传动》
北大核心
2020年第12期83-87,共5页
Electric Drive
关键词
多逆变器并联
下垂控制
下垂系数
自愈能力
小信号模型
multiple inverters in parallel
droop control
droop coefficient
self-healing ability
small signalmodel
