Energy Digest

The small-signal stability of an LFAC transmission line controlled by Droop Control Strategy can be determined using eigenvalue analysis, with system parameters such as droop gains, operating frequency, and transmission line characteristics affecting stability. The overall dynamic is influenced by the sum of AC/AC converter droop gains. System stability is affected by factors including line length, R/X ratio, operating frequency, and voltage.

A new power electronic converter modeling strategy is proposed for grid-connected inverters in asymmetrical power grids, extending existing blackbox models from dc-dc converters. The approach provides a sequence-domain representation of the dynamic behavior of commercial three-phase inverters under unbalanced conditions. Experimental tests validated the model's performance during an asymmetric voltage sag.

Equivalent DQ sequence-domain models of unbalanced three-phase passive impedances can generate second-order harmonic content due to differing phase impedance values, which hinders dq0 transformation advantages; Fortescue's theorem offers a solution by representing asymmetrical signals as linear combinations of symmetrical sequences. A novel equivalent model has been derived in the sequence domain, accounting for interaction between zero-sequence and positive/negative sequences, with experimental validation results.

Port-Hamiltonian theory is used to create a unified energy structure for dispatchable virtual oscillator control in grid-forming converters, allowing for the regulation of amplitude, synchronization, and power dispatch within a single framework. The formulation involves a dissipative Port-Hamiltonian system with a key property that enables an exact gradient decomposition compatible with quadratic energy storage. This leads to almost-global asymptotic stability and local exponential convergence, as well as control over the energy landscape.

The proposed adaptive stochastic spectral embedding (ASSE) method efficiently and accurately estimates probabilistic characteristics of AC-OPF solutions while minimizing power losses. It uses a Bayesian compressive sensing-based algorithm to enhance its performance and provides accurate and fast evaluations compared to Monte Carlo simulations. The ASSE method offers practical decision-making bounds for generator outputs and operating costs under uncertainty.

A new pricing rule minimizes demand payments and eliminates out-of-market (OOM) make-whole payments while preserving locational marginal prices (LMPs) and ensuring revenue adequacy. The rule achieves favorable generator profits, reduced price volatility, and a more transparent price signal. However, it increases demand payments to ensure the uniform allocation of ramping costs.

Decentralized power-system stability analysis and control is developed, focusing on the asymptotic stability of an equilibrium set rather than a single point, using input-output differential passivity (IODP) to analyze local requirements. The framework requires each bus to have sufficient IODP, quantified by an index, with a passivation controller compensating for shortfalls in IODP shortage. This approach provides a scalable solution for system-wide stability certification and control under highly variable operating conditions.

The article presents an open synthetic test system for the Jordanian transmission grid, assembled from public sources with a focus on high-renewable operation within small synchronous systems. The model replicates the annual energy mix at technology level and provides a benchmarking framework for various power system research topics, including resource adequacy, renewable integration, fuel-supply resilience, and interconnection studies. The dataset is released to support reproducible power system research in the Middle East region.

A dual-mode EV onboard charger has been proposed that can operate from both three-phase and single-phase supplies. This charger uses Active Power Decoupling (APD) to reduce the required DC link capacitance when charging from a single-phase supply, achieving more than an order of magnitude reduction. The proposed topology is verified through simulation under various conditions.

A modular IoT-enabled remote laboratory platform for hybrid energy system research and engineering education combines renewable energy emulators, battery storage, and programmable loads within a three-interface architecture. The platform uses a Talk2M VPN cloud to connect web HMI, TIA Portal, and MATLAB/Simulink interfaces with an industrial PLC and IoT gateway, supporting deterministic local control and secure remote access. The hierarchical energy-management algorithm validates the platform's performance under identical wind and irradiance profiles.