Mixed State Estimation Method For Integrated Energy System Based On Data Preprocessing

The integrated energy system covers a variety of energy types,such as electricity,heat and gas,etc.,with complex operating states and diverse dynamic characteristics of equipment.Building an integrated energy system can not only increase the flexibility of the social energy supply system,but also reduce the environmental pollution caused by energy consumption,which is of great significance to improve energy efficiency.With the development of integrated energy system and data transmission system,the real-time monitoring of running status of integrated energy system is becoming more and more important.State estimation,as one of the important means of integrated energy system operating state monitoring,can not only master the actual situation of the integrated energy system,identify the bad data,but also provide reliable data support for the follow-up dispatching department.The main work is as follows:(1)The data processing method is used to clean and repair the measurement data of the comprehensive energy system,including the identification and correction of abnormal data and the filling of missing data.The correlation detection method of quantity measurement is used to identify the abnormal data.Lagrange interpolation algorithm is used to correct the abnormal data.Cubic spline interpolation algorithm is used as the filling algorithm of missing data.After data processing,the measured data has higher reliability,which provides an important data basis for subsequent state estimation.(2)A distributed state estimation model for individual heat network and power grid system is constructed,and a node degree search zoning method based on equilibrium region is proposed according to the correlation of quantity measurement.Weighted least square method is used to construct the state estimation model of each subsystem,and Newton method is used to solve the state estimation model,and the parallel state estimation of each subsystem is realized on the premise of ensuring the system observability.Compared with the traditional centralized state estimation algorithm,the system can shorten the period of state estimation and increase the accuracy of state estimation after the node degree search partition processing based on the equilibrium region.(3)A hybrid state estimation model for integrated energy system based on coupling equipment is established.A hybrid state estimation method for electricity-thermal-gas integrated energy systems is proposed,which includes a coupled state estimation model and a distributed state estimation model.The proposed hybrid state estimation algorithm improves the state estimation effect from two aspects.On the one hand,the coupling model can improve the measurement redundancy of the integrated energy system,thus increasing the accuracy of the state estimation.On the other hand,distributed state estimation is implemented in each energy subsystem,which improves the effect of state estimation again and reduces the time of state estimation.From the perspective of realizing comprehensive energy system state estimation,this paper focuses on the improvement of the accuracy of measurement data by data processing technology,the research of individual energy system state estimation algorithm and the innovation of state estimation model.The research results can provide reference value for the future work of state estimation and situational awareness of integrated energy system.