摘要
针对直流微电网中变换器阻抗特性及稳定性问题,从系统级高度将变换器的输出阻抗作为研究对象,对适用于光伏系统中的连续导电模式(CCM)下Boost型变换器进行小信号建模,得到变换器的开环输出阻抗。分析了变换器在下垂控制方式下的闭环输出阻抗的小信号模型及其影响因素,总结出规律性结论,便于对直流微电网的稳定性进行分析。最后,根据阻抗比判据,分析了线路中不同寄生电容对系统稳定性的影响。仿真结果验证了上述分析的正确性。
For the impedance characteristics of the converters and its stability problems in DC microgrid, the output impedance of converter was investigated from system-level height. Moreover, in order to obtain the open-loop output impedance, small signal modeling of the Boost type DC-DC converter in CCM was derived. Based on analysis of the small signal model and effect factors for the closed-loop output impedance under droop control some conclusion were drawn to analyze the stability of DC microgrid. Finally, according to impedance ratio criterion,the stability of the system which was influenced by parasitic capacitance was analyzed. Simulation results are also given to demonstrate the correctness of the analysis.
出处
《低压电器》
2013年第4期26-31,共6页
Low Voltage Apparatus
基金
电气设备电气绝缘国家重点实验室开放基金(EIPE12209)
陕西省重点学科建设专项资金资助项目(00X901)
国家自然科学基金(50977078)
关键词
直流微电网
输出阻抗
下垂控制
寄生电容
DC microgrid
output impedance
droop control
parasitic capacitance
