A novel multi-objective security-constrained power management for isolated microgrids in all-electric ships

Since isolated microgrids, such as all-electric ships (AES), have limited generation and finite inertia, frequency and voltage violations are prone to happen in these microgrids. Therefore, it is necessary to have a power management framework for optimal scheduling of microgrids while achieving stable real-time operation. This paper introduces a novel multi-objective security constrained power management (MO-SCPM) framework for AES, based on a computationally-efficient optimization technique, Pareto Concavity Elimination Transformation (PaCcET). PaCcET transforms a multi-objective space to a transformed objective space and then utilizes a single-objective optimizer to find all the non-dominated solutions of the original multi-objective space. The new framework efficiently integrates steady-state and dynamic security limits, such as power balance, active power generation, reactive power generation, voltage magnitude, line flows, frequency, and voltage transient in a unified framework. The new power management method is applied to a notional AES model to find the best compromise solution that not only minimizes the individual active power set-point adjustments but also minimizes voltage set-point adjustments while keeping the operating and security constraints satisfied. The results are then compared to the computationally-expensive multi-objective technique based on Non-dominated Sorting Genetic Algorithm II (NSGA-II) as a well-known multi-objective optimization benchmark.