Fast distributed control design for DC linked microgrids

摘要

A centralized controller for a DC linked hybrid microgrid requires costly communication infrastructure. To minimize the costs, in this paper, a sparse distributed controller is formulized by introducing an l(1) penalty term to the cost function to enforce at most not more than neighbor-to neighbor links. This makes the design nonlinear which exhausts large amount of computation times. Therefore, by some transformations, the nonlinear cost function is converted to an approximate quadratic one; which has better optimization characteristics, i.e. fast convergence rate and unimodal. The proposed fast distributed controller Design (FDCD) algorithm is employed for a 3-bus and a 69-bus (consist of 7 hybrid microgrid) distribution systems controller design. The results indicate that the obtained sparse distributed controller performs well as if a centralized controller is in operation. It can successfully suppress various types of faults injected to the AC, DC, and DC link sides of the network. The algorithm convergence rate is substantially lower than some other contestant algorithms. A problem that is solved by FDCD in 5 min, it takes 10 min for the others to be completed.