Probabilistic Load Flow Analysis And Risk Assessment For Power Systems With Wind Power Integration Considering The Dispatching Strategy

With the intensification of the energy crisis and environment pollution,humans have to seek for clean and renewable energies.Wind power,as one of the most technology-mature renewable energy,has been attracting increasing attention and is being developed rapidly around the world.Meanwhile,the intermittency and uncertainty of wind power brings more uncertainties to the power system,which results in great challenges to the safe operation of power system.Probabilistic load flow(PLF)considers uncertain factors to obtain the probabilistic distributions of nodal voltage and branch power flow,which is a powerful tool to revel the operating characteristics.Thus,this paper mainly studies the calculation method of probabilistic load flow and its applications in risk assessment with the background of wind power integration.The main work is as follows:(1)This paper proposes a novel probabilistic load flow model for power systems integrated with large-scale wind power,which considers the multi-time scale dispatching features.The ramp limitations of the units have been considered for the entire duration of the study period.Thus,the coupling of the system operation states at different time sections has been taken into account.For each time section,the automatic generation control(AGC)strategy is considered,which overcomes the defect that all variations are compensated by the slack bus alone.(2)This paper proposes a risk assessment method for power systems integrated with large-scale wind power,which considers the multi-time scale dispatching features.This method utilizes utility theory to define the risk indicators for nodal voltage and branch power flow in both component-level and system-level.Based on the high-risk period identification and weak link recognition,this method can comprehensively assess the risk level and direct the operation.Test results on the IEEE RTS-79 system validate the correctness and effectiveness of the proposed approaches.Therefore,the paper can provide instructive information for the power system operators.