Coordinated Optimal Dispatch Of The Power System Including Distributed Energy Resources

Recently, Chinese policies greatly promote the development of the grid-connected Distributed Energy Resource (DER) and the informational andinteractive smart grid. In this context, the cooperation dispatching of thepower grid including lots of DERs is a meaningful issue to eliminate theconflicts between the main grid and DERs (or consumers).It firstly aims on the optimization model and its solving method ofaggregating DERs based on the operation characteristics of virtual powerplant(VPP). A multi-objective optimization model with priority is proposed tospecify the technical and economic two-layer management mode of thevirtual power plant as the target functions with priority. The proposed modelis solved by decomposing it into two step optimization models based on thesatisfaction function. Then a joint optimization model of distribution networkincluding virtual power plants is established and solved by the approximatedynamic programming. With the joint optimization model, the networkperformance, such as frequency deviation, voltage deviation, power controlcan be improved because of the rapid control ability of virtual power plants.The second concerned point focuses on the cooperative dispatch of DERand the charging-discharging-storage integrative station(CDSIS) containingelectric vehicles (EV) and the second-use of electric vehicle batteries. Animproved dispatching model is proposed based on security constrainedoptimal power flow (SCOPF) to realize the temporal and spatial decoupling,with the power-transferring function of EVs and batteries. The improvedmodel firstly obtains the24-hour power outputs of traditional generators andthe total output of DERs and the CDSIS by treating them as a whole(represented by a VPP). Then it optimizes the DERs’ outputs considering thetopological structure of power grid to decouple the spatial correlation.Thirdly, an algorithm combining the interior point method and the update of the regulatory variables is proposed for the chance constrained stochasticoptimal power flow (S-OPF) model of power system including DERs. Theequivalent conditions of chance constraints are calculated based on cumulantsand Cornish-Fisher series. The regulatory variables are proposed to changethe chance constrained stochastic optimal power flow into a deterministicoptimal power flow (D-OPF) model. The update of the regulatory variablesis proposed to abtain iteratively the optimal solution of the S-OPF model. Theproposed method are tested on the IEEE14-bus and118-bus systems. Itsprecision, sensitivity and calculation are also analyzed in the case study.Lastly, a multi-controller interactive coordination scheduling model ispresented and applied to the dispatch problem of the power system includingmultiple renewable controllers. The optimal controller models the activeoptimization of the DERs’ controlling center. The traditional power griddispatch model is also considered as a controlling center. In the dispatchingmodel, a controlling center can plan its power output on its own according toits resources characteristics and multiple optimization objectives. Based onthe interactive coordination dispatching model, two optimal models(peer-to-peer and with priority) and two operating model (normal andabnormal) are also proposed. The detailed coordination rules are alsodesigned accordingly. The collaborative optimization method based onsatisfaction is applied to solve the proposed models. The coupling variable iscoordinated using collaborative optimization. The coordination of satisfactionis proposed to resolve the objective conflict between multiple optimal controlcenters in parallel optimization. The model and the method are validated inthe simulation example.