Hengxu Zhang

The energy transition requires not only the deployment of low-carbon technologies, but also the organization of dispersed resources into forms of coordination that are operationally effective, institutionally legitimate, and socially durable. The existing transition frameworks explain institutions, niches, and system formation well, yet they are less explicit about how coordination intensifies across physical, digital, and social domains, why technically capable arrangements may remain socially fragile, and how aggregation redistributes authority and visibility. Building on Xue et al.’s Cyber–Physical–Social Systems in Energy (CPSSE) framework, this Perspective develops an interpretive elaboration of CPSSE to address that gap. Its main contribution is a shared analytical vocabulary that links uncertainty, staged coordination, and aggregation, and that recasts virtual power plants as socio-technical accomplishments rather than merely control architectures. Rather than proposing a measurement model, this article uses concepts drawn from information, coordination, and aggregation to examine what conditions render distributed energy governable, whose participation is stabilized or marginalized, and how legitimacy, accountability, and user acceptance become constitutive conditions of coordination. The Perspective contributes to energy social science by clarifying how cyber–physical capability interacts with governance conditions, participation, and institutional durability, while identifying an empirical agenda for studying how coordination is negotiated, stabilized, contested, and unevenly distributed across distributed energy systems.

Virtual power plants (VPPs) require compact aggregate parameters that remain usable across dispatch and stability timescales. This paper presents a multi-timescale VPP aggregation framework based on coupled principal component analysis (PCA) and Copula modeling. The framework outputs aggregate power, capacity bounds, regulation headroom, ramp limits, and reliability-qualified fast-response capacity for day-ahead, intraday, real-time, and electromechanical transient (DA/ID/RT/ET) applications, and it uses a parallel event-state channel to aggregate virtual synchronous machine (VSM) inertia and damping for transient studies. The PCA stage reduces the online dimension from O(N·d) to O(k), while the Copula stage preserves non-Gaussian dependence in forecast errors. Validation is conducted on reproducible fixed-seed synthetic VPP benchmarks with proxy dispatch, AGC, and frequency-event studies. In the reproduced Case 1 benchmark, out-of-sample uncertainty estimation error decreases from 94.13% under the independence assumption to 2.08%, with online aggregation latency of about 0.012 s at N=800. The event-state channel also improves frequency-response metrics relative to the no-ET baseline. The submission package includes materials for reproducing the synthetic benchmark results together with a reference PSS/E UDM specification.

Urban hybrid off-grid power systems (UHOGPS) face critical frequency stabilization challenges as renewable energy sources (RES) and electric vehicles (EVs) dominate modern grids, introducing complex nonlinearities, stochastic disturbances, and dynamic uncertainties. To address these limitations, this paper proposes a multi-stage extended state observer with generalized active disturbance rejection control (MSESO-GADRC), a novel framework that hierarchically decomposes disturbances into targeted frequency bands for precise mitigation. The key contribution lies in its multi-stage ESO architecture, which uniquely integrates two-, three-, and four-stage observer configurations with adaptive bandwidth tuning to isolate and suppress low-, medium-, and high-frequency disturbances while compensating for unmodeled dynamics. Simulations under renewable intermittency, EV charging transients, and load disturbances demonstrate the framework’s superiority: it achieves 43.40–85.71% smaller frequency deviations and 38.46–64.34% faster settling times compared to 1PD-DOP-3PID, SESO, FO-IMC, and SBL-PI controllers. These advancements validate the MSESO-GADRC’s robustness in UHOGPS with 70% RES/EV penetration, offering a critical pathway to stabilize decarbonized grids. By explicitly resolving the trade-off between disturbance rejection and system nonlinearity compensation, this work provides a foundational control paradigm for future high-renewable microgrids.

Residual current protection can detect and isolate the grounding (leakage) fault of low-voltage distribution networks in time, which is an essential technical measure to reduce electric shocks and fire accidents and improve power supply safety. This paper systematically analyzes the operating characteristics of low-voltage distribution networks and proposes a distributed residual current protection method based on closed sections. It utilizes the capabilities of a distribution IoT platform to provide comprehensive measurement information for the entire substation area. A method was introduced to divide the low-voltage distribution substation into different protection closed surfaces, defining the current phasor at the external contact point of the closed surface and the remaining current of the closed surface. A calculation method for the critical current based on the remaining current of the closed surface for fault detection was proposed. Case studies have shown that this method is less affected by the inherent current and can significantly improve the sensitivity of protection. For TN-C and TN-C-S systems, in the selection of closed surfaces, the repeated grounding point of the neutral line is excluded from the closed surface. This method can also overcome the impact of residual current changes when load switching, demonstrating the flexibility of the new principle.

With the increasing integration of renewable energy sources into the power grid via power electronic devices, the dynamics of the system became more complex, leading to a broadened frequency spectrum of the electrical signals. Therefore, wideband synchronous measurement has become an essential tool for panoramic information perception of the grid. Current protocols are designed for fundamental frequency data transmit, which is ineffective for the wideband frequency data. In this article, we propose a wideband communication protocol that encompasses a message frame construction and a real-time communication technique for variable-length wideband data. The communication procedure of the message frames remains fully compatible with the IEEE C37.118.2 and can simultaneously transmit harmonic, interharmonic, and fundamental frequency measurement data. The protocol is instantiated on hardware and a wideband monitoring system to validate its effectiveness, followed by the theoretical and practical analysis of communication performance. The field application of the wideband measurement for an electric vehicle charging station is demonstrated to validate the efficiency and practicability of the proposed communication protocol.

Fundamental phasor plays a prominent role in fault identification, location, and clearance. However, because of the transient process of fault transmission line and current transformer (CT), the fault current trends to contain decaying dc component (DDC). This makes it difficult for the precision of phasor estimation algorithm to meet the requirements of advanced applications based on fundamental phasor. In order to eliminate the adverse effects of DDC, a Full-cycle DFT(FCDFT)-based phasor estimation algorithm is proposed in this paper. The sum of four quarter-cycle samples at interval combinations are utilized to extract and remove frequency domain error terms introduced by DDC into the fundamental phasor. The algorithm is compared with existing techniques in MATLAB environment. The comparison results reveal the proposed technique can eliminate DDC interference with any decay time constant under noise with a small amount of additional computation based on traditional DFT. Moreover, the proposed algorithm has strong robustness to interferences.

Battery energy storage (BES) systems play an increasingly important part in power system operation because of their high efficiency and decreasing cost. This article proposes a mixed integer linear programming (MILP) model of battery degradation considering both depth of discharge (DoD) and state of charge (SoC), which can reflect the battery degradation mechanism. To improve computational efficiency for the economic scheduling of power system, a novel one-dimensional linearization is proposed to linearize this two-variable function, which significantly reduces computation burdens without loss of accuracy. Considering the battery degradation cost, a day-ahead economic scheduling model is built and a MILP algorithm is applied to solve it. The effectiveness of the MILP-based battery degradation model for economic scheduling is validated using the modified IEEE 30-bus system. For comparison, other existing battery degradation models are also implemented in the same system.

Circuit breakers are important components for removing short circuits in power systems and ensuring safe operation. The operation of circuit breakers may not be predicted and thus cause accidents, so there is an urgent need to innovate means to assess the operation status of power equipment and monitor the operation status of power grids in full real time, to improve the monitoring capability of major key equipment, and to study key technologies for the digital twin of circuit breakers to support the safe and stable operation of transmission networks and the digital transformation of energy systems. This paper establishes the multi-physics field coupling calculation model of the circuit breaker opening process, completes the simulation calculation of the circuit breaker opening process, gets the distribution and change trend of parameters such as electric field, pressure, temperature, density, and airflow speed inside the interrupting chamber, and analyzes the flow characteristics inside the interrupting chamber in different opening processes. We select the characteristic parameters and provide data support for the establishment of fault diagnosis based on the digital twin of the circuit breaker.

The transmission line parameters vary with the change of temperature, which has a significant impact on power system state estimation (SE). Based on the theory of electro-thermal coordination (ETC), this paper proposes two ETC-SE approaches with the consideration of transmission line temperature. The heat balance equation (HBE) is combined with the conventional weighted least square SE for establishing an ETC-SE model. Moreover, an augmented Jacobian ETC-SE approach is developed by integrating the HBE into pseudo measurements and the line temperature into state vectors. The Jacobian matrix is augmented correspondingly and the partial differential coefficients of measurements to line temperature are provided, which enables to calculate line temperature and voltage phasors simultaneously. Furthermore, in order to accelerate the solving process, an improved two-step ETC-SE algorithm is proposed, in which the SE and temperature estimation are decoupled and solved via alternate iteration. The effectiveness of the proposed ETC-SE approaches is verified by the IEEE 14-, 39-, and 118-bus systems. The results show that the proposed ETC-SE approach is effective to reduce the calculation errors and possesses good convergence performance with varying environmental circumstances and ill-conditioned branches.