GCN-LSTM spatiotemporal-network-based method for post-disturbance frequency prediction of power systems

Owing to the expansion of the grid interconnection scale,the spatiotemporal distribution characteristics of the frequency response of power systems after the occurrence of disturbances have become increasingly important.These characteristics can provide effective support in coordinated security control.However,traditional model-based frequencyprediction methods cannot satisfactorily meet the requirements of online applications owing to the long calculation time and accurate power-system models.Therefore,this study presents a rolling frequency-prediction model based on a graph convolutional network(GCN)and a long short-term memory(LSTM)spatiotemporal network and named as STGCN-LSTM.In the proposed method,the measurement data from phasor measurement units after the occurrence of disturbances are used to construct the spatiotemporal input.An improved GCN embedded with topology information is used to extract the spatial features,while the LSTM network is used to extract the temporal features.The spatiotemporal-network-regression model is further trained,and asynchronous-frequency-sequence prediction is realized by utilizing the rolling update of measurement information.The proposed spatiotemporal-network-based prediction model can achieve accurate frequency prediction by considering the spatiotemporal distribution characteristics of the frequency response.The noise immunity and robustness of the proposed method are verified on the IEEE 39-bus and IEEE 118-bus systems.

Research on heritage characteristics based on railway architectural heritage database in Jinzhou section of the Peking-Mukden Railway

This research interprets the background of Jinzhou section of the Peking-Mukden Railway,and puts forward 65 heritages as cases based on the scope definition and investigation.After the data collection,processing,and visualization,the database composed of 9 sub-databases,with B/S architecture mode,is constructed based on SQL server platform.The ArcGIS tool is used to analyze the distribution of the heritages,including spatial distribution characteristics,spatial agglomeration,and spatial equilibrium.“Image and model information database”and“text attribute information database”is used to analyze the architectural ontology features.The conclusions are drawn as follows:1)The integral distribution has the characteristics of“cohesion”,while the 5 medium types of heritages show obvious and different directions.2)The overall pattern of spatial agglomeration is characterized by high cohesion with a single high agglomeration point as the core.The low agglomeration area shows a point-line-point pattern.3)The integral heritages and three main types of buildings differ in distribution,and the equilibrium is low.The architectural ontology analysis shows that the image information can be used as the basis for ontology characteristics analysis,architectural form and style judgment,and architectural functional space analysis.