Research On The Situation Awareness And Evaluation Of The Smart Distribution Network

With the access of the large amount of renewable energy sources,energy storage devices and multiple loads,the safe operation of the distribution network is faced with severe challenges.Meanwhile,a large number of operating and monitoring data have been collected in the distribution network with the development of smart terminals.In order to evaluate and predict the operation state of distribution network and realize the active management and prevention of the distribution network,the situational awareness of distribution network based on monitoring data is studied in this paper.The situational awareness of distribution network is an important method to obtain the operation state of distribution network.By adopting this method,various factors which affect the operation of active distribution network can be recognized and comprehended in certain space and time scope.What’s more,the safe operation state of distribution network can be predicted accurately and effectively.The situational awareness model of distribution network can be divided into awareness layer,comprehension layer and prediction layer.The main research contents of this paper are developed according to this progressive relationship.The main work of this paper is as follows:Firstly,the real-time monitoring solution for buses and branches of distribution network is proposed by using phasor measurement unit(PMU).A multi-stage distribution system hybrid state estimation method is proposed utilizing real-time measurement extracted from PMU.Thus the perception of real-time operation state can be realized in the distribution system.Secondly,considering N-1 branch outages and short-term fluctuations of loads,the system of distribution network for evaluating operation status is constructed with the requirements of security,power supply reliability and economy.Then,the security risk assessment of distribution network based on risk theory is studied,and the real-time evaluation method of the maximum power supply capacity of distribution network based on the repeated power flow is proposed.Furtherly,taking the power quality index as an example,the method of early warning of distribution network operation index is studied.Thirdly,a load ultra-short-term prediction method based on least squares support vector machine is proposed by taking ultra-short-term load forecasting as the core,and prediction errors are corrected.On the basis of state estimation,the safety state prediction of distribution network is studied for predicting the future states of bus voltages.Finally,according to the actual operation data of the regional distribution network in Qingdao,Shandong Province,the network is comprehensively analyzed and evaluated by employing the proposed method,and the situational awareness scheme proposed in this paper is also verified.