Risk Assessment Of Power Grid Dispatching Decision Considering Photovoltaic Systems Penetration

In view of the increasing consumption of traditional fossil energy and environmental pollution,photovoltaic,as a renewable and environmentally friendly new energy,has attracted wide attention from the energy and power industry.In recent years,the capacity of photovoltaic power plants has been increasing,and the scale of photovoltaic grid-connected has increased with each passing year.However,the randomness,fluctuation and uncertainty of photovoltaic power output make the decision-making of power grid dispatching more complex,and also have a certain impact on the risk of power grid dispatching decision-making.Therefore,it is very important to study the risk assessment of grid dispatching decision-making with photovoltaic generation.The work done in this paper is as follows:Firstly,the risk sources of grid dispatching decision-making for photovoltaic power generation are analyzed,and the basic steps of power system risk assessment are introduced.The fault models of components in power system are studied,and the fault parameters of components are elaborated;The distribution characteristics of load forecasting error and photovoltaic forecasting error are studied and fitted respectively;Then,two kinds of methods for selecting the system state in estimation are analytic method and simulation method,and their characteristics and applicable objects are introduced respectively.Because of the large amount of calculation and time-consuming of risk assessment for dispatching decision-making,starting with the fast calculation method of power flow distribution in power system,based on some existing research results,the definitions of node transfer distribution factor and line outage distribution factor are introduced,and their calculation formulas are deduced;This paper establishes the risk index system from four aspects: line overload risk,reserve shortage risk,load shedding risk and light abandonment risk,defines two-level indexes according to the characteristics of four kinds of risk indexes,gives the calculation method based on Monte Carlo simulation method,and establishes the risk assessment model for optimal dispatching decision-making of power grid with photovoltaic generation based on Monte Carlo simulation method.The evaluation process of the model is listed in detail.Taking the IEEE RTS-79 power system with photovoltaic access as an example,according to the optimal scheduling model considering photovoltaic access,the optimal scheduling decisions with different photovoltaic acceptance levels are generated.The risk assessment model established in this paper is used to analyze the risk assessment of the above dispatching decisions,and four kinds of risk indicators are calculated respectively;Through the comparative analysis of different dispatching decision-making risk indicators,the accuracy and practicability of the risk assessment model established in this paper are verified,which has certain reference significance for the formulation and selection of power system dispatching decision-making.