Homogeneous Polynomially Parameter-Dependent Fuzzy Switching Control of Nonlinear Cyber-Physical DC Microgrid System Against Multiple Malicious Attacks

This paper focuses on the design of homogeneous polynomial parameter-dependent (HPPD) fuzzy switching security controller for nonlinear cyber-physical DC microgrid systems under multiple malicious attacks. Firstly, for the multiple cyber attack scenario with both denial of service (DoS) and false data injection (FDI), an HPPD fuzzy switching controller is designed, which can cope with DoS attack and has FDI attack signal compensation, and the corresponding augmented error system model of the DC microgrid is established. In addition to observing unmeasured system states and unknown FDI attack signals, this model also introduces homogeneous polynomial method and multi-mode fuzzy switching mechanism (MMFSM) to achieve accurate estimation and relaxation control. The so-called MMFSM aims to re-divide the space spanned by the fuzzy membership function into a set of non-overlapping subspaces, which can also be called different modes, by introducing a weight coefficient. Then, by designing a pair of exclusive gain matrices for each mode, a co-design method of HPPD-type multi-mode fuzzy switching security controller and state observer is proposed. More importantly, an improved multi-mode fuzzy switching mechanism (IMMFSM) is proposed by introducing a pair of weight coefficients. Compared with the previously proposed co-design method, IMMFSM can achieve lower conservatism. Finally, the effectiveness and advantages of the proposed theoretical results are verified and analyzed in a nonlinear cyber-physical DC microgrid system.