The current global climate is complex with an increasing frequency of extreme weather events. The randomness, variability, and intermittency of new energy sources pose significant challenges for the balance between power generation and consumption in electricity grids. This challenge is particularly pronounced during extreme weather events such as cold waves, which aggravate the challenges of power supply stability. Accurate prediction of the wind power output can reduce the need for system backup capacity, ensuring the stable operation and reliability of the power system. However, current prediction models do not effectively consider the impact of extreme weather, leading to low prediction accuracy and large deviations. Additionally, the mechanisms by which extreme weather affects wind power differ from those under normal weather conditions. Extreme weather events such as cold waves are rare, and sample data are scarce, making it difficult to establish precise prediction models. To address these issues, this study proposes a wind power output prediction correction method based on time-series generative adversarial networks. First, a time-series generative adversarial network algorithm was used to generate samples from meteorological and power data, constructing an extreme weather meteorological and power database to effectively address the issue of sample scarcity. Second, the improved particle swarm algorithm (IPSO) and Bayesian optimization (BO) algorithm were used to optimize the parameters of single-prediction algorithms such as eXtreme gradient boosting (XGBoost) and least absolute shrinkage and selection operator (LASSO). Subsequently, by combining the algorithm performance and principle of maximum diversity, the optimal algorithm combination was determined using the evaluation indicators of the prediction error and Pearson correlation coefficients to construct an extreme weather power prediction model under the stacking ensemble learning framework, overcoming the limitations of single algorithms and effectively improving the prediction accuracy. Finally, Support Vector Regression (SVR) was used to construct a power prediction correction model for similar days, correcting the predictions. Through verification using an actual cold wave case study, the proposed method demonstrated significantly improved prediction accuracy and performance compared to single algorithms and conventional prediction models.
The mutual optimization of a multi-microgrid integrated energy system (MMIES) can effectively improve the overall economic and environmental benefits, contributing to sustainability. Targeting a scenario in which an MMIES is connected to the same node, an energy storage coordination control strategy and carbon emissions management strategy are proposed, and an adaptive step-size method is applied to improve the distributed optimization of MMIESs based on the alternating direction multiplier method (ADMM). Firstly, the basic framework of MMIESs is established, and a coordinated control strategy limiting the time of charge and the discharge of the battery storage system (BSS) is proposed. Then a multi-objective optimization model based on operating and environmental cost is formulated. Considering that different microgrids may be managed by different operators and a different convergence speed of multi-objective optimization iteration, an adaptive step-size distributed iterative optimization method based on ADMM is used, which can effectively reduce the cost and protect the privacy of each microgrid. Finally, a system composed of three microgrids is taken as an example for simulation analysis. The results of distributed optimization are accurate, and the proposed coordinated control strategy can effectively enhance the revenue of ESS, which verifies the effectiveness of the proposed method.
8 May 2024 in International Journal of Electrical Power & Energy Systems
Due to the anti-peak shaving characteristics of wind power under the operation mode of “power determined by heat”, a large number of wind power is abandoned at night. In order to solve the problem, this paper proposes a method of coordinated operation of ground source heat pump (GSHP) and combined heat and power (CHP) units. Through indirectly reducing the generation power of CHP units, the accommodation space of wind power in power grid is improved. A two-stage robust optimal scheduling model of regional integrated heat-power system (RIHPS) considering the uncertainty of wind power generation and power load is established. And a distributed solution method based on Alternating Direction Method of Multipliers (ADMM) method and column-and-constraint generation (C&CG) algorithm is designed. Then, the Locational marginal pricing strategy with the goal of guiding users to participate in wind power accommodation is analyzed. The numerical simulation results show that the wind power accommodation capacity of the integrated system under the operation mode of “power determined by heat” can be improved through installing GSHP at CHP units and using price signal guidance.
A large number of bubbles generated by the air agitation device in an external melting ice storage system can cause the disturbance of the ice–water mixture, which can enhance the heat transfer and contribute to the reduction in energy consumption. The structural design and optimization of the air agitation device in an external melting ice storage system is the key issue for energy savings. In this study, the influence of different orifice spacings and diameters on the distribution of the gas–liquid flow field, gas holdup, heat-transfer coefficient, and power consumption in the ice storage tank was investigated by numerical simulation. The simulated results showed that the heat-transfer coefficient of the ice–water mixture with air bubbles should be 3–5 times higher than the natural convection when the air superficial velocity is 0.03 m/s. The gas holdup was mainly affected by the orifice spacing, and the maximum varied from 5.0% to 8.2%. When the orifice spacing was less than 150 mm, the gas holdup changed a little in the horizontal direction, and the uniformity became worse when the orifice spacing was larger than 180 mm. An orifice diameter larger than 3 mm can improve the heat transfer and cause less air-compressing energy consumption, which decreased by approximately 1.62%.