【摘要】 针对直流微网中微源常规下垂控制方案下功率均分与电压质量不能兼顾的不足,文中考虑各微源容量不尽相同,以各微源负载率相同为功率均分目标,设计了基于低速通信的改进下垂控制方案,以功率补偿的PI控制保证功率均分,以电压补偿的PI控制保证电压质量。建立该控制方案下的多微源网状系统模型,进行了静态稳定分析。为防止可能发生的个别微源下垂系数设置不合理引发的问题,引入满载微源连锁停发功率信号的机制以保证微网系统可正常运行。在MATLAB/Simulink中模拟搭建了3电源6母线直流微网系统进行了热插拔实验、下垂系数设置不合理致某一微源满载运行的实验,验证了该系统在可能出现的上述工况下均能保持系统稳定、功率均分和电压质量。更多还原

【Abstract】 The disadvantage of the conventional droop control scheme of DC micro-grid is that it should compromise between the reasonable load share and voltage regulation. In order to achieve the same load ratio among the microsources of different capacities,an improved droop control approach is proposed based on the low-bandwidth communication( LBC),in which the load share accuracy and reasonable voltage deviation are achieved by load share compensation and voltage deviation compensation respectively. The multi-source DC network with the improved droop control approach is modeled to analyze its small-signal stability. The mechanism of stopping sending power signal from the over-loaded sources because of the miss setting of droop coefficients is introduced to ensure the micro-system operation.A 3-source 6-bus DC micro grid is built in MATLAB/Simulink to check the overall behavior of the proposed approach.The hot swap and the scenario of some micro sources over-loaded with others at lower load rate due to improper setting of droop coefficients is simulated. The simulations verify that the stability,the power share accuracy and the voltage deviation quality can be achieved by the proposed approach.更多还原