To support the path-aware trading clearing of the inter-provincial electricity market in China, a uniform modeling method for the hybrid AC/DC transmission network is proposed in this paper. This method uses a radial ...
To support the path-aware trading clearing of the inter-provincial electricity market in China, a uniform modeling method for the hybrid AC/DC transmission network is proposed in this paper. This method uses a radial equivalent network to replace the AC network for trading path identification. The depth-first search method is then leveraged to enumerate all trading paths in the unified AC/DC network. To demonstrate the effectiveness of the proposed method in the inter-provincial market clearing, the path-aware market clearing model and the high-low matchmaking market clearing model are established. Case studies based on a 6-province test system verify the effectiveness of the proposed method and compare the differences between the two market clearing mechanisms.
In recent years, decay-like fracture has become the main fracture form of composite insulators, and the faults caused by it seriously threaten the safety and stability of the powersystem. In this paper, decay-like fr...
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With the increasing penetration rate of renewable generation, the challenges arising from its randomness and intermittent nature are becoming more pronounced. In particular, wind and photovoltaic power ramp events pos...
With the increasing penetration rate of renewable generation, the challenges arising from its randomness and intermittent nature are becoming more pronounced. In particular, wind and photovoltaic power ramp events pose a serious threat to the secure and stable operation of powersystems, and even lead to frequency instability and load shedding. Based on the long short-term memory neural networks (LSTM), this paper proposes a novel renewable power ramp events (RPREs) forecasting approach. First, filter the key tie-lines. Second, the LSTM network was driven by the known time series of wind, PV, load, and tie-line power to forecast the tie-line power for the next hour, thereby determining the adjustable capacity of the tie-line. Finally, the regulatory capability of the grid is considered to judge the occurrence of a power ramping event. Case study demonstrates that the proposed method can effectively predict power ramping events and meets the requirements of online assessment.
Accurate forecasting of day-ahead electrical load is a key to optimize the operation of the integrated energy system (IES) and a fundamental function of the cyber-physical system (CPS) of IES. Due to the characteristi...
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In order to cope with the impact of extreme weather on distribution network, a two-stage multi-objective game optimization-based method of energy storage configuration for distribution network resilience enhancement i...
In order to cope with the impact of extreme weather on distribution network, a two-stage multi-objective game optimization-based method of energy storage configuration for distribution network resilience enhancement is proposed in this paper. First, typical scenarios are generated based on N-k contingency as well as distributed photovoltaic (DPV) output characteristics, and evaluation indexes of resilience and economy are established. Then a two-stage multi-objective optimal configuration model is proposed, considering the operating state and resilience demand of distribution network before and after the power supply transfer. Finally, the model is solved by multi-objective particle swarm (MOPSO) and Nash game. simulation results on the modified IEEE33-node model demonstrate that the proposed method can achieve good equilibrium solution between resilience and economy.
To solve the problem of active power imbalance in distribution network with high penetrations of photovoltaic (PV) under extreme weather, the paper proposes a distributionally robust optimal allocation method of energ...
To solve the problem of active power imbalance in distribution network with high penetrations of photovoltaic (PV) under extreme weather, the paper proposes a distributionally robust optimal allocation method of energy storage considering extreme scenarios. Firstly, considering that the effect of energy storage on enhancing the resilience of distribution network is strongly related to its location, resilience indexes based on node evaluation are established to select the installation sites of energy storage. Secondly, in view of the correlation and randomness of PV output and load, the typical scenarios with the empirical probability distribution are generated based on Frank Copula joint probability distribution function. Then, Kullback-Leibler divergence is utilized to characterize the probability distribution ambiguity set of the typical scenarios. Based on the ambiguity set, a two-stage distributionally robust optimization model for energy storage capacity is established to minimize the cost of energy storage investment and distribution network operation. For further improving the resilience, an operational resilience index as a chance constraint considering extreme scenarios is embedded into the model. Finally, the case study shows that the proposed method can effectively improve PV accommodation capacity of distribution network and reduce load loss in extreme scenarios.
An optimal energy storage sizing method for integrated energy system (IES) considering carbon trading and demand response is presented in this paper. Firstly, to effectively limit carbon emissions, a reward-penalty la...
An optimal energy storage sizing method for integrated energy system (IES) considering carbon trading and demand response is presented in this paper. Firstly, to effectively limit carbon emissions, a reward-penalty laddered carbon trading model is designed to convert carbon emissions into system costs or revenues. Secondly, the integrated demand response (IDR) model for electrical-cold-heat loads is established based on time-of-use price to enhance the operational flexibility and economy. Then, based on these two sub-models, an optimal energy storage sizing model is built to minimize the total life cycle cost including investment, operation and carbon trading cost. Finally, the simulation results indicate that a successful balance between low-carbon and economy can be achieved by the proposed method.
To ensure the efficient operation and healthy development of photovoltaic power generation systems, reliable distributed photovoltaic power prediction is significant. However, the lack of modeling ability of existing ...
To ensure the efficient operation and healthy development of photovoltaic power generation systems, reliable distributed photovoltaic power prediction is significant. However, the lack of modeling ability of existing distributed photovoltaic power forecasting methods for dynamic spatiotemporal correlation of distributed photovoltaic power data limits the further improvement of prediction accuracy. Therefore, a distributed photovoltaic ultra-short-term power forecasting method based on spatial-temporal attention mechanism and graph convolutional networks is proposed in this paper. Firstly, distributed photovoltaic cluster is divided into sub-regions and graph structured data can be generated with each sub-region being a node on the graph. Then, spatial-temporal attention mechanism is used to adaptively capture spatiotemporal correlation information and dynamically update adjacency matrix. Finally, spatial-temporal convolution is used to extract deep spatiotemporal features of distributed photovoltaic power data and achieve regional power prediction. The validity and progressiveness of the model have been verified in real world data sets.
As the proportion of wind power in grid continues to increase, more and more newly built or expanded wind farms are facing problems such as lack of historical samples and insufficient training of prediction models. Wi...
As the proportion of wind power in grid continues to increase, more and more newly built or expanded wind farms are facing problems such as lack of historical samples and insufficient training of prediction models. With the increasing frequency of extreme weather events, most wind farms also face problems such as scarce samples of extreme weather scenarios and large power forecasting errors. In response to the above-mentioned issues, this paper proposes an wind power interval prediction method based on conditional generative adversarial networks (CGAN) and kernel extreme learning machines (KELM). With the historical samples of extreme weather scenarios, a large number of new samples are generated through CGAN. Based on KELM, an interval prediction model under extreme weather is constructed. Compared to point prediction, this model can provide richer probability information, and compared to other interval prediction methods, the results show an effective improvement in prediction performance.
The loss of electricity during transmission cannot be ignored, and a large number of power consumers are seeking flexible and affordable distributed generation methods to reduce electricity costs. However, a large num...
The loss of electricity during transmission cannot be ignored, and a large number of power consumers are seeking flexible and affordable distributed generation methods to reduce electricity costs. However, a large number of distributed photovoltaic (PV) connections pose challenges to electric power dispatch and the security of powersystem. Accurate PV power forecast can solve these problems, which requires a large amount of accurate historical data to build forecast model. This article proposes a spatiotemporal interpolation method to complement historical data of PV sites. Wavelet packet transform (WPT) is applied to decompose original time sequence to stable sequence and fluctuant sequence. To eliminate the fluctuations caused by cloud movement, dynamic time warping (DTW) is used to regularize fluctuant sequences of adjacent PV sites. Finally, through spatial interpolation, a precise historical data can be obtained. The case study shows that under cloudy conditions, proposed interpolation method reduces the NRMSE by 0.51% compared to the direct interpolation algorithm.
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