Hierarchical Stability Control Strategy of DC Micro-Grid Considering Constant Power Load Performance
Xie Wenqiang1, Han Minxiao1, Yan Wenli2, Wang Chao1, Yuan Dong3
1. School of electrical and Electronic Engineering North China Electric Power University Beijing 102206 China; 2. School of Mathematics and Physics North China Electric Power University Beijing 102206 China; 3. State Grid Jiangsu Electric Power Co. Ltd Nanjing 210000 China
Abstract The stability research of DC micro grid mainly focuses on the controller design of all components, and lacks adequate analysis at the system level. With the high proportion penetration of constant power load, the negative resistance characteristic cannot be ignored. Therefore, this paper established an equivalent model of large capacity DC micro grid system with droop control suitable for parallel connection of multiple energy storage converters, and discussed the stability of the system. Considering the nonlinearity of the system, this paper firstly determined the stability of the system equilibrium point. Secondly, the influence of constant power load and system parameters on the stability of the system was analyzed, and the load carrying capacity of the system under different system parameters was quantified and verified by simulation. Finally, a hierarchical stability control strategy was designed according to the results of theoretical analysis, including three aspects: initial parameter selection, virtual resistance adjustment and load adjustment. The simulation and experimental verification were carried out.
Xie Wenqiang,Han Minxiao,Yan Wenli等. Hierarchical Stability Control Strategy of DC Micro-Grid Considering Constant Power Load Performance[J]. Transactions of China Electrotechnical Society, 2019, 34(16): 3430-3443.
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2019, Vol. 34 
