Study On Optimal Operation Strategies For Grid With High Penetration Of New Energy In Electricity Market Environment

New energy power generation(NPG)industry is developing rapidly.This development can mitigate problems of conventional power source shortage and environmental pollution;however,due to volatility and randomness of the NPG,it also brings some troubles to peak modulation,frequency modulation and spinning reserve configuration of the integrated power system.To realize optimized allocation of large scale energy assets and ensure safety,reliability and efficiency of the power system,in recent years,China government put forward an overall request to build a unified,open,competitive and orderly electricity market nationwide.This thesis aims to mitigate problems of peak modulation,frequency modulation and spinning reserve configuration,on the basis of China's electricity market reform,optimized operation methodologies and strategies of NPG high-penetrated system are studied.Main contents of this thesis are as follows:(1)Most of the existing spinning reserve configurations take the conventional power generation as the only support of the spinning reserve,and the new electric equipments such as energy storage and flexible loads were rarely considered.Aiming at this limitation,Concept of power grid generalized spinning reserve is proposed.Referring to serialization modeling and Copula function that can describe the dependent structure of random variable values,mathematical models of power grid equivalent loads(i.e.difference between power grid original load and NPG output power at the same time)fluctuation quantity and predictive deviation are established.Considering characteristics of system frequency response(SFR)and aiming for minimum NPG acquisition cost,blackout lost and NPG curtailment,an optimized spinning reserve configuration methodology for NPG high-penetrated power grid is proposed.According to actual operating data of a regional NPG high-penetrated power grid in Xinjiang,feasibility of the proposed methodology is verified through simulation.(2)According to the virtual power plant(VPP)technology,multiple power sources can be built-up to promote new energy consumption;it is a good idea to mitigate problems of peak modulation and frequency modulation.Therefore,calculation models of NPG output power predictive deviation and fluctuation suppression are established.Furthermore,considering time-and-space complementary characteristics of wide area NPG output power,an orderly grouping methodology of NPG aims to minimize systematic peak modulation and frequency modulation cost is proposed.This orderly grouping methodology replaces NPG individual dispatching with orderly grouped power sources dispatching,which can lower dispatching difficulty and realize high-efficiency operation of NPG integrated power system.Taking an NPG high-penetrated power grid in Northwestern China as an example,feasibility of the proposed methodology is verified.(3)The “benchmark pricing” can hardly accurately match the influence of NPG output power randomness and volatility on ancillary service cost(ASC)increasing.Calculation model of regional NPG caused ASC is established.Considering relationship between NPG output power fluctuation and regional power system comprehensive NPG output power fluctuation,cost allocation model of NPG caused ASC is established.Furthermore,based on benchmark price partly reflects static investment and operation cost of power system,a calculation model of NPG integration price based on ASC allocation is established,which can provide references for NPG selection,dispatch plan formation and NPG output power optimization and control in electricity market circumstance.Based on an NPG high-penetrated power grid in Northwestern China,feasibility of the proposed methodology is verified.(4)On the basis of NPG orderly dynamic grouping,referring to overall structure of China ' s power system dispatching and control methodology of virtual power plant(s)participating power system dispatching,a basic structure of NPG high-penetrated integration power system bi-level optimized dispatching is established.Furthermore,taking reasons for ASC into account,a bi-level optimized dispatching model considering NPG integration ASC is established.The upper-level dispatching model aims to minimize the sum of power system generation cost and ASC;it can be used on daily or hourly optimized dispatching of NPG integrated power system.The lower-level aims to make NPG orderly grouping output power positively correlate to upper-level dispatching plan;it can realize real-time optimized dispatching of NPG integrated power system.On the basis of an NPG high-penetrated power grid in Northwestern China,feasibility of the proposed methodology is verified.Results of this thesis can provide theoretic and technology references for reducing ASC and realizing high-efficiency operation of NPG high-penetrated power system.