| The penetration rate of the distributed energy resources（DERs）in distribution systems is increasing,which promotes the transformation of traditional distribution systems into active distribution systems（ADS）.ADS can flexibly regulate DERs and provide active support for the transmission system by participating in the energy and reserve market on the basis of meeting its own load demand.It not only realizes the bidirectional power flow between the transmission system and the ADS,but also enhances the information interaction between the transmission system operator（TSO）and the distribution system operator（DSO）.Therefore,it is urgent to propose a novel energy and reserve market clearing mechanism to meet the interaction between energy and information between new transmission and distribution systems.DSO can to adopt suitable market bidding and clearing strategies to improve the economics of its own scheduling operation and reduce the impact of new energy uncertainties on the operation of the transmission system by providing reserve resources,so as to achieve the optimal allocation of resources and the economic operation of the whole system.Based on the above background analysis,The main research work of this dissertation is as follows.1)The scheduling operation scheme and market-oriented hierarchical management mode of transmission and distribution collaborative power system are expounded.Taking into account the network parameters and operating characteristics of the transmission system and the distribution system,the DC optimal power flow（DCOPF）model of the transmission system and the AC optimal power flow（ACOPF）model of the distribution system are presented.Based on the operation characteristics of DERs,the operation model of various distributed energy sources is constructed.2)Considering the cooperative operation relationship of transmission and distribution systems,a clearing mechanism for the energy market in the power system is established.Taking into account the multi-period operation characteristics of the DERs,a centralized energy market clearing model in the transmission and distribution collaborative power system is proposed.The second-order cone relaxation method is used to transform the convex optimization problem to facilitate the solution.A test system coupled with the transmission and distribution system is used to verify the validity of the energy market clearing model.The numerical results show that the above model can reduce the total operating cost of the transmission and distribution system,the consumption of fossil fuels and the locational marginal price of each system after energy market clearing,so as to realize the economic operation of the whole system.3)From the perspective of DSO,the optimal bidding and energy management strategy behavior of DSO and TSO in energy and reserve markets is simulated.Taking into account the clearing process of energy market,reserve market and distribution market,a novel market operation mechanism of DSO as price maker is proposed.Considering the TSO-DSO interaction and the uncertainties of DERs,a stochastic bi-level convex optimal model of ADS participating in energy and reserve market is established.Based on the Karush–Kuhn–Tucker（KKT）condition,strong duality theory and Big-M method,the above nonlinear bi-level mode is transformed into a single-layer mixed integer second-order cone programming（MISOCP）model.The effectiveness of the proposed stochastic bi-level optimization model is verified by example analysis.Numerical results prove that DSO’s participation in the energy and reserve market joint clearing mechanism as a price maker can effectively reduce its own operating costs and the reserve cost of the reserve capacity of the transmission system.At the same time,it can increase the enthusiasm of the DSO to participate in the electricity market and the consumption of new energy by the system. |
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