<![CDATA[Distributed Cooperative Secondary Control (DCSC) is a critical layer in the hierarchical control architecture of islanded microgrids, responsible for eliminating steady-state voltage and frequency deviations introduced by primary droop control. However, conventional linear DCSC strategies suffer from four fundamental limitations: (i) asymptotic convergence with settling times dependent on initial conditions, (ii) continuous communication requirements that consume excessive bandwidth, (iii) vulnerability to abrupt topology changes during Plug-and-Play (PnP) operations, and (iv) performance degradation under communication time delays. This paper proposes a unified Finite-Time Event-Triggered DCSC (FT-ET-DCSC) framework that simultaneously addresses all four challenges. A nonlinear signed-power consensus protocol guarantees exact voltage synchronization within a strict, calculable finite time bound that is independent of initial conditions. A state-dependent event-triggered communication mechanism reduces bandwidth utilization by over 98% relative to a continuous-transmission baseline while provably excluding Zeno behavior. Rigorous Lyapunov-based stability analysis proves finite-time convergence, and a Lyapunov–Krasovskii functional approach establishes delay-dependent robustness, with stable operation under time-varying communication delays confirmed in simulation up to 500 ms. Furthermore, the framework maintains absolute stability under switching communication topologies induced by PnP events via a common Lyapunov function argument. Comprehensive simulations of a heterogeneous 4-DG microgrid validate the theoretical claims, demonstrating up to a 4.28× convergence speedup over linear methods, seamless recovery during dynamic DG disconnection and reconnection, and stable operation under severe network delays.]]>
