With development of power electronic technology, the paralleled current-controlled voltage source converters (CCSs) and virtual synchronous generators (VSGs) system has advantages in providing power and voltage/frequency regulation at the same time in rural area or remote island. However, the paralleled system faces great challenges in safe and stable operation due to their limited thermal capacity and weak anti-disturbance ability, especially during fault periods. This paper focuses on transient stability and stability-oriented control design of the paralleled CCS-VSG system. First, mathematical model of the paralleled system is established and then the effect of two kinds of CCSs’ current injection angle (active current and reactive current) on VSG’s transient stability has been revealed through extended equal area criterion. Based on the theoretical analysis results, transient stability improvement control is put forward by controlling the CCS to track the VSG’s frame. Compared with the conditions that only active-or reactive current is provided by the CCS, the system can achieve the best transient performance when the proposed control is adopted. Moreover, the effect of CCS’s capacity on transient stability of the VSG has also been discussed. Finally, both Lyapunov’s method and simulation/experimental results are provided to validate the correctness of theoretical analysis.

Satellite Internet as a representative of 6G offers a globally resilient service of communication, navigation, timing and remote sensing at multiple temporal and spatial scales. Facing the 6G era, the next generation smart grid (NGSG) will be constructed with the assistance of a unified space-ground network. This accounts for the unified network’s attributions of wide coverage, large base of sources and loads, and the complex environment. Hence, an integrated satellite-terrestrial network (ISTN) framework is proposed in this letter. It aims at empowering the NGSG under the massive renewable energy sources integration, which includes conditions of an intelligent urban grid, a reliable remote area grid, and a resilient grid to emergency. Heterogeneous data such as remote sensing and navigation signals are aggregated and leveraged in the proposed ISTN framework. Information entropy theory is used to coordinate the space- and ground-based networks elaborately, maximizing the utilization of network resources pointedly and efficiently. A cyber-physical platform is used based on an actual LEO satellite Internet test constellation to validate the proposed ISTN, which reveals the superiority and promising future.

The safety of grid-connected voltage-controlled inverter is threatened by transient angle instability due to fault. The impact of different active power control (APC) and reactive power control (RPC) on the inverter's transient angle stability hasn't been fully investigated. To fill this gap, firstly, a unified model of the voltage-controlled inverter considering different APC and RPC is put forward. Based on the proposed unified model, the effect of different APC and RPC loops on the inverter's transient angle stability are qualitatively analyzed by using equal area criterion (EAC). Then, the TS multimodeling method which is based on the Lyapunov function is applied to evaluate the effect of control parameters on the inverter's transient angle stability quantificationally. Finally, the above analysis is verified based on an experiment. It is found that lowering inertia improves the inverter's global stability but decreases the inverter's first swing stability. Transient stability of the inverter can be improved by increasing damping component of the inverter. Transient angle stability of the inverter is influenced by the RPC loop. With the increase of the output voltage of the RPC loop, reference reactive power, and output voltage of the inverter, transient angle stability of the inverter can be improved.

The grid-forming converters would integrate battery energy storage systems (BESSs) in islanded microgrids for smoothing out the uncertain fluctuations of renewable energy resources. However, gird-forming converters would pose transient instability risks under large disturbances, which could require fast and accurate stability assessment methods in such challenging and uncertain cases. In this work, a hierarchical time-series assessment and control (HTSAC) framework is proposed for assessing the transient stability of grid-forming converters in islanded microgrids. The proposed HTSAC framework offers a gated recurrent unit (GRU) neural network alternative for an intuitive and accurate trajectory prediction in early post-fault stages. Subsequently, an emergency ride-through control (ERC) strategy is proposed which leverages the proposed neural network approach for enhancing the prediction results in real-time assessments of microgrid transient stability. The initial input horizon of GRU is optimized to avoid intense trial-and-error design burdens incurred in conventional data-driven assessment methods. Simulation and experimental results are presented to validate the effectiveness of the proposed HTSAC on an islanded microgrid in south China. The results also point out that the GRU of the prediction layer with a quantile loss function would ensure a timely ERC in the proposed HTSAC approach to renewable energy-based converter operations.

Disruptions in ground communications during disasters significantly impede unmanned aerial vehicle (UAV)-based power line inspections, slowing down fault localization and threatening system secure operation. This paper proposes a spatiotemporal precise routing strategy for the integrated satellite-terrestrial network, focusing on achieving stable communication and balanced energy consumption among the UAV swarm under signal fluctuations. Here, satellite internet and flying ad-hoc network (FANET) are fully utilized concurrently, which is tailored to practical demand of post-disaster power line inspections and overcomes communication collapse. The proposed strategy features superior flexibility and resilience in various complex and hostile environments. The simulation results demonstrate that the proposed strategy outperforms traditional routing algorithms, supporting stable signal transmission for multi-UAV-based power line inspections, extending cluster operational time, and enhancing the speed of post-disaster power system recovery.

Grid-forming converters not only provide voltage and frequency support for remote islanded microgrids but also induce increasing instability risks during disturbances caused by typhoons, rainstorms, etc. With the assistance of LEO satellite internet, a data-driven predictive control (DPC) strategy is proposed to enhance the stability and resilience of remote islanded microgrids against widespread and frequent disturbances. Owing to the high-speed and wide-bandwidth communication services provided by the LEO satellite internet, the proposed DPC can establish timely and reliable data interaction among participating converters with acceptable latency, and then a two-layer gate recurrent unit (GRU) neural network is applied to predict the converters' dynamics precisely despite the parameter mismatch drawbacks of mathematic models. Furthermore, the proposed DPC achieves the derived consensus dynamically among converters such that the coherence and consistency are guaranteed effectively. Extensive case studies on practical remote islanded microgrids have been conducted to validate the effectiveness of the proposed DPC in coping with various types of disturbances and oscillations, effectively ensuring the system stability with considering the delays induced by the LEO satellite internet