State-space-method based stable analysis of DC distribution network

Nowadays, with the rapid development of distributed sources and application of renewable energy, systems based on microgrids have been widely used. To connect AC and DC networks, a type of microgrid called Hybrid Microgrid has been introduced thanks to its advantage of decreasing the energy loss compared to classic microgrids. In this paper, a hierarchical control strategy is chosen to regulate the voltage and the active power in the system. Based on this control strategy, an algorithm that deduces the steady-state stability of the DC network is analyzed in detail. With this algorithm, we are able to use certain symbolic variables to characterize different parameters influencing the stability. In the end, a linear radial DC network with one load and two controlled sources model is established in Matlab/Simulink platform to verify the algorithm. The result of the simulations demonstrates that the algorithm deduces the stability of network accurately.