IET Renewable Power Generation最新文献

Zhang, J., et al.: The impact of lightning strike to multi-blade on the lightning overvoltage and stresses of arresters in offshore wind farm. IET Renew. Power Gener. 15, 2814–2825 (2021).

In Section 2.5, the unit of Table 2 was incorrect, and the authors have modified Table 2 as follows:

The authors apologize for this error.

Large-scale energy storage solutions are crucial to ensure grid stability and reliability in the ongoing energy transition towards a low-carbon, renewable energy based electricity supply. This article presents the evaluation of a novel low-head pumped hydro storage system designed for coastal environments and shallow seas. The proposed system addresses some of the challenges of low-head pumped hydro storage including the need for larger flow rates and reservoirs as well as the requirement of machinery with high efficiencies across a wide operating range to accommodate larger changes in gross head during storage cycles. It includes several units of contra-rotating reversible pump-turbines connected to axial-flux motor generators within a ring dike, as well as dedicated machine- and grid-side control. The technology allows for independent control of each runner, making it possible to adapt to the specific operating conditions of low-head systems. In this work, a numerical approach is used to simulate the system's performance and dynamic behaviour under various operational conditions, including energy generation, storage, and grid support of a 1 GW system with 4 GWh of storage capacity. The potential system performance for energy balancing cycles is evaluated, and a sensitivity analysis is conducted to assess the influence of scaling the motor-generators on performance and footprint of the plant. Additionally, the capability and limitations of the system to respond to grid demand fluctuations and provide frequency regulation services are assessed. The results demonstrate that the low-head pumped hydro storage system is a viable large-scale energy storage solution, capable of round-trip efficiencies above 70% across a wide operating range. By increasing the maximum power of the electric machines, the maximum head range of the whole system is increased which correlates with a threefold increase in energy density per unit area. The dynamic simulations further show that the system can rapidly change its power output allowing it to provide frequency regulation services. Allocating 20% of its nominal power as a reserve, the new power setpoints can be reached within a maximum of 5 s independent of its initial state of charge.

To address the impact of distributed generation (DG) access on the traditional protection configuration methods of distribution networks (DNs) and to facilitate the swift and effective protection of lines by protection devices under fault conditions, an adaptive current protection method for three-phase short-circuit faults in active distribution networks (ADNs), based on local information, is proposed. Initially, the applicability issues of traditional protection are examined, and the limitations of the existing protection scheme in ADNs are highlighted. Subsequently, the fault characteristics of ADNs are analysed, taking into account the output characteristics of DGs under short-circuit faults, which form the foundation for the proposed protection method. Following this, an adaptive current protection method based on local information is introduced, utilizing a dual criterion of phase and magnitude to adjust line protection, with a specific implementation strategy for the protection scheme provided. Finally, the proposed protection scheme is validated using PSCAD/EMTDC simulation software, with results demonstrating that the scheme enables rapid and efficient protection action under fault conditions across the entire line.

Renewable energy sources generate power intermittently, which poses challenges in meeting power demand. The use of transient energy storage systems (TESSs) has proven to be an effective solution to this issue. Hence, it is crucial to understand the impact of TESS components design on sizing the power-train system during fast frequency response. While power-train systems have been extensively discussed, the impact of dc-link voltage on the TESS power-* train and associated power electronics specification requirements has not been evaluated. This study uses a sodium-nickel chloride (NaNiCl₂) battery-based TESS to assess different power-train options. Specifically, the research investigates the impact of variations in dc-link voltage due to battery regulation and state-of-charge (SoC) on the design of the TESS-connected power-train system, since these will be the major contributions to the power-train system performance envelope. This paper also compares the performance of TESS power-train systems with four different schemes. The power-train models include the detailed modelling of energy sources, power electronic converters, and transformers based on published parameters and testing data. Additionally, the study proposes a performance index to evaluate the superiority of the four schemes in terms of voltage and current rating, efficiency and battery size.

Transitioning to renewables is critical to address the Caribbean's vulnerability to imported fossil fuel price volatility and concerns about climate change. This study presents a first-of-its-kind comprehensive analysis of 17 illustrative pathways varying the impact of e-fuel imports, grid interconnections and an accelerated energy transition towards the Caribbean's carbon neutrality by 2050. The research method is based on techno-economic principles for designing a cost-optimal energy system. An optimisation tool is used, the LUT Energy System Transition Model, to analyse the various pathways. The study finds that high uptake of renewables in Caribbean energy systems significantly lowers costs and enhances reliability, crucial for building competitive and resilient economies. Renewable energy dominated pathways show 7–24% lower cumulative costs compared to alternatives, with grid integration reducing costs by 1–10%. Accelerated transition pathways incur 3–12% higher costs than complete defossilisation by 2050. Solar photovoltaics, wind power, batteries, and electrolysers are pivotal for achieving carbon neutrality by 2050. Importing e-fuels reduces system costs by 7–16% and supports local resource use. Offshore renewable energy overcome land limitations, driving sustainable development and a vibrant blue economy. High electrification levels with renewable energy, sector coupling, and Power-to-X solutions enhance system efficiency and flexibility. Given the dominance of solar photovoltaics, the Caribbean's energy transition could be more appropriately called a ‘Solar-to-X Economy’. This research contributes to the international perspective on sustainable energy transition for islands.

With the share of renewable generation increasing, considerable synchronous generators have been displaced. This trend results in the decline of system inertia and thus raises the frequency secure issue. Concurrently, electric vehicles (EVs) proliferate. Numerous EVs hold a huge potential of frequency regulation in case of contingency as EVs are able to achieve primary frequency responses (PFRs) via vehicle to grid chargers. However, the value of frequency responses from aggregated EVs has not fully exploited. This paper, proposes a chance constrained scheduling model incorporating the ability of PFRs from aggregated EVs. The proposed model characterizes uncertainties associated PFR capacities from aggregated EVs and wind power forecast errors by the Wasserstein-metric ambiguity sets, which do not rely on distributional assumption, and then formulates uncertainties-related constraints as distributionally robust (DR) chance constraints. These DR chance constraints are reformulated as tractable linear programs. Consequently, the proposed model leads to a mixed-integer linear program. Numerical results on a modified IEEE 39-bus system show that incorporating PFR from EVs can reduce total costs from $4,540,396 to $4,431,233, which is reduced by 2.4%. The proposed model also achieves better reliability compared to traditional methods, demonstrating the distributionally robust optimization in enhancing electricity scheduling and rising renewable integration.

Microgrids integrating inverter based resources face challenges like stability issues during voltage fluctuations and reliance on diesel generators in islanded mode. This paper presents a novel control strategy for photovoltaic and wind-integrated microgrids to enhance reliability and efficiency. The strategy utilizes a modified phase-locked loop with droop control for seamless synchronization in grid-connected and islanded modes. Central to this approach is the localized autonomous controller with a socket protocol interfaced communication layer, dynamically managing operations based on real-time conditions such as generation, load, and battery state of charge. By integrating battery storage systems, the strategy reduces diesel generator dependency during grid outages. Comprehensive simulations and controller hardware-in-the-loop testing validate its effectiveness, demonstrating improved stability and decreased reliance on diesel generators. The socket protocol enhances real-time communication, monitoring, and optimization of microgrid operations, ensuring optimal battery storage system utilization and minimal diesel usage. The proposed strategy addresses critical microgrid challenges, offering significant advancements in enhancing system resilience.

In modern power systems, the integration of inverter-based renewable energy sources has significantly reduced system inertia, leading to heightened frequency fluctuations and potential instability within multi-area interconnected microgrids. To counter this, a virtual inertia and damping controller utilizing battery energy storage, leveraging the virtual synchronous generator concept is proposed in this paper. This controller supplements inertia by modulating active power flow, thus stabilizing frequency during high renewable energy source penetration periods. Additionally, to enhance load frequency control, a cascaded controller combining adaptive neuro-fuzzy inference system-assisted fractional-order PID with a nonlinear FOPI controller is introduced. It should be noted that improper controller parameters can worsen frequency deviations and system stability. Hence, a whale optimization algorithm optimizes control parameters using the integral time absolute error based objective function. Simulation studies on a modified IEEE 10-generator 39-bus power system, considering various disturbances like stochastic load-generation, nonlinear generation behaviours, and time delay, validate the effectiveness of the proposed controller. Comparative analysis demonstrates the superior resilience of the cascaded control approach in managing contingencies within low-inertia power systems, with a remarkable performance improvement of 87.9811% compared to existing control methods.

Wind farm flow control (WFFC) is an emerging technology involving coordinated operation of wind turbines within a wind farm to achieve collective goals. To design and evaluate controllers, wind farm flow models are used that capture the key aerodynamics of the system whilst remaining computationally efficient for iterative controller design. This review article reveals considerable heterogeneity in the potential wind farm flow models to study WFFC. Lack of consensus is problematic as differences in results from separate studies are attributable to both controller and model effects, making it hard to draw comparative conclusions. Hence, an expert elicitation is completed surveying WFFC practitioners. Two key contributions are presented. First, a guide to available software for WFFC, which, combined with results from an expert elicitation on flow model requirements, facilitates selection of suitable software for investigating WFFC problems. Secondly, critical future research areas are identified. Research into high fidelity wind direction models (particularly transient effects) and wake meandering models for fatigue load investigations are identified as critical to the field. A lack of consensus regarding the importance of atmospheric boundary layer effects, wake induced turbulence, and lateral wind correlation identifies the requirement of sensitivity studies in these areas.

With the development of distributed energy resources and intelligent energy management technologies, park-level integrated energy systems (PIESs) are essential for multi-energy flow conversion and utilization. However, coordinating the upstream energy sources, internal energy stations, distribution networks, and downstream loads within the PIES framework remains a challenge. Developing a station-network coordinated planning scheme for PIES confronts challenges, such as overly complex models that are difficult to solve and the difficulty of implementing standard methods for medium and long-term planning. This paper proposes a multi-stage coordinated planning approach for PIES, containing energy stations, multi-energy networks, and load aggregation nodes. The energy equipment and energy networks are precisely modelled to enhance the reliability of the planning scheme. The chance-constrained programming (CCP) method is adopted to address uncertainties arising from renewable energy generation. Additionally, the improved big-M method and second-order cone (SOC) relaxation technique are utilized to manage non-linear elements, transforming the model into a mixed-integer second-order cone programming (MISOCP) form to enhance solution efficiency. A case study illustrates that the proposed method enables effective allocation of equipment and networks, outperforming single-stage planning by reducing investment costs, enhancing facility utilization rates, and facilitating renewable energy integration.