Yifan Li

Wildfire‐induced multi‐point faults seriously threaten the resilience of power electronics‐dominated power systems. To address this issue, this letter proposes a game‐theoretic resilience control strategy for wildfire scenarios by integrating a probabilistic tripping model, a topology‐aware structural criticality indicator, and a system‐level resilience metric. A non‐cooperative game framework is developed to coordinate local control actions while balancing tripping risk, load restoration, and control cost. Experimental results from a real‐time digital simulator‐based hardware‐in‐the‐loop platform demonstrate that the proposed strategy improves post‐fault recovery and enhances system resilience under extreme wildfire conditions.

Wind power integration challenges conventional emergency control methods for isolated power grids (IPGs). Phase Sequence Exchange (PSE) technology provides a new solution. By using power electronic devices to switch the three-phase sequence, the generator power angle can be reduced by 120°. In contrast to conventional PSE methods, this paper proposes an enhanced transient stability scheme for high wind power penetration IPGs based on PSE technology. First, a high-proportion wind power IPG model is constructed to derive the power angle characteristics. Then, the prerequisites for PSE is determined to improve transient stability and the optimal triggering time for PSE is defined. On this basis, a PSE control scheme based on these basic elements is proposed. Finally, the performance of the scheme is demonstrated by using the real-time digital simulator (RTDS). Tests results show that the proposed scheme can prevent system instability and achieve optimal control performance in multiple scenarios.

Power systems are severely threatened by wildfires, which can potentially trigger N–k cascading faults and lead to large‐scale blackouts. To mitigate these risks, this paper proposes a novel critical fault‐set identification model. First, an LSTM‐based framework is introduced to model the time‐series evolution of line states under varying load levels and external wildfire conditions. Meanwhile, a spatio‐temporal attention mechanism is introduced to account for both the topological connectivity among transmission lines and their temporal dependencies. This integrated model not only addresses the temporal continuity in cascading failures but also accounts for topological complexity in the grid. Experimental results show that the model achieves a high identification accuracy of 98.05% on the test set, surpassing the performance of baselines including Transformer‐based and CNN‐LSTM architectures. Furthermore, it demonstrates strong adaptability to different load conditions and wildfire intensities, underscoring its practical value in wildfire scenarios.

The integration of doubly‐fed induction generators (DFIGs) into wind farms presents significant challenges to current differential protection (CDP). In this study, an adaptive CDP principle for wind farms is proposed. By introducing the virtual restraint current, the restraint current is significantly reduced under low‐resistance faults. Additionally, a boundary model is constructed based on the complex relationship of current phasors. On this basis, the cosine compensation coefficient is formulated solely using the amplitudes and phases of the two‐terminal currents, which further enhances the ability to identify high‐resistance faults. The principle can also lock the restraint coefficient according to the current amplitude, thereby reducing false trips. Finally, the performance of the scheme is demonstrated by Hardware‐in‐the‐loop (HIL). Test results indicate that the proposed principle identifies faults more reliably and rapidly than the conventional CDP. The proposed principle is novel and feasible both in theory and practical applications.

Virtual synchronous generator (VSG) controlled isolated power grid has been widely concerned because of its advantages of voltage support. However, in the presence of significant disturbance, the system would face the risk of transient instability like conventional power grid. As a recently developed control method, phase sequence exchange (PSE) can not only stabilize the system but also avoid additional reduction in system capacity and inertia. Nonetheless, PSE increases redundant power electronic devices into the grid. Therefore, this paper establishes a transient model for VSG-controlled isolated power grid initially. Based on this, a control method is proposed to realize the effect of PSE by reducing the power angle of VSG through power electronic control in the inverter, named as virtual phase sequence exchange (VPSE). This control method effectively avoids the need for external PSE devices while improving the transient stability. Furthermore, this paper investigates the VPSE technology through the extended equal area criterion (EEAC) and modern control theory, with results indicating that compared to PSE, VPSE has better transient control effects. Finally, the proposed scheme is verified by physical experiments on the real-time digital simulation platform (RTDS).

Cascaded H‐bridge power electronic transformers (CHB‐PET) can efficiently connect AC/DC distribution networks, realizing power transmission and electric energy conversion. Once a pole‐to‐pole DC fault occurs on the low‐voltage direct current (LVDC) side of CHB‐PET, the fault current has a fast rise and high amplitude, which easily leads to the rapid blocking of power electronic devices and makes it difficult for DC line protection to obtain fault information. A stepwise blocking scheme of PET is proposed for LVDC network protection. When the fault on the LVDC side of PET is detected, cascaded H‐bridge and low‐voltage H‐bridge of dual‐active‐bridge are blocked first, and then high‐voltage H‐bridge of dual‐active‐bridge is blocked after a 5 ms delay. The stepwise blocking can provide fault information for DC line protection. On this basis, wavelet packet transform is employed to extract different frequency components of fault current. The energy of the specific frequency band corresponding to the switching frequency of DAB and the total energy of all frequency bands contained in the fault current is calculated; then their ratio can be utilized to construct the protection scheme. Finally, the PSCAD/EMTDC simulation results verify the feasibility and effectiveness of proposed protection scheme based on stepwise blocking of CHB‐PET.

An isolated power grid (IPG) is electrically weakly connected to the utility power grid, and intentional controlled islanding (ICI) can secure IPG from external faults. Phase sequence exchange (PSE) is a recently developed emergency control technology in which power electronic devices are used to switch the three-phase sequence, thereby reducing the power angle of the generator by 120° and preventing the system from losing stability. This article proposed a coordinated control scheme for PSE and ICI. After the system is disturbed, the local measurement of the interconnection line between IPG and the utility grid is used to assess the system's stability. PSE is adopted to adjust the power flow direction to reduce the transient energy of IPG. At the same time, using the internal measurement of IPG, the transient energy of IPG is calculated in real-time, and the critical energy is rolling refreshed based on offline information. After PSE reduces the energy of IPG to lower than the critical energy, IPG is safely disconnected from the utility grid. The proposed scheme needless to adjust the internal generator or load of IPG and is verified on the real-time digital simulator platform with a PSE prototype.

Power angle stability of power systems is one of the main factors which restricts the power transmission capacity. In order to prevent the power angle instability of power systems, phase sequence exchange (PSE) is a recently developed emergency control technique that reduces the power angle by 120°. This paper proposes a new phase sequence exchange technology based on a modular multi-level converter (MMC). In this paper, the concept of deceleration area ratio is proposed, that is used to characterize the power angle stability of the power system, and the phase sequence exchange theory based on an MMC is analyzed. A phase sequence exchange circuit based on a modular multilevel converter (MMC) is designed. In this paper, the system parameters of the MMC-based PSE are optimized. Finally, a model is developed on PSCAD. The simulation results show that the MMC-based phase sequence exchange technology can effectively improve the power angle stability of the power system.