Research On Distributed Optimal Operation And Control Technology Of Active Distribution Network

Driven by the "30·60" target,China is undergoing a profound transformation of its energy structure.With the large-scale integration of distributed generations represented by wind power and photovoltaics,the system structure and the operation main bodies of distribution network has become increasingly complex.The distribution network has gradually evolved into active distribution network(ADN)which is capable of flexible and proactive power regulation.In this context,the disadvantages of traditional centralized regulation methods of distribution network such as high communication requirements and poor robustness have become increasingly prominent.As a result,the centralized regulation methods cannot meet the safe and stable operation requirements of the distribution network any more.In contrast,the distribute regulation method doesn`t require the overall coordination of the regulation center.It can overcome the bottleneck of centralized regulation in terms of computing and communication efficiency through local communication and parallel computing,which is more adaptable to the large-scale access of distributed generations and provides new ideas for the improvement of the safe and economic operation of ADN.However,as the system resources of ADN become more and more abundant,the operating characteristics of ADNs are becoming more and more complex.Besides,the significant uncertainty of various distributed generations also brings severe challenges to the reliable operation of ADNs at various regulatory scales.Therefore,it`s urgent to conduct in-depth research on the distributed optimal operation and control technology of ADN facing the background of large-scale access of distributed power sources and the trend of new load terminal access,which is of vital importance for the improvement of distributed power consumption capacity as well as the safe and economic operation of ADN.The main research contents of this paper are as follows:In view of the distributed optimal operation and control architecture of ADN,an overall regulation framework for the key issues of distributed optimal operation and control of ADN is established.First,three key issues of the distributed optimal regulation of ADN are analyzed.Then,the overall regulation framework of the distributed optimal regulation of ADN is established.On this basis,for the self-dispatching problem of micro-integrated energy system(MIES)connected to ADN,a self-dispatching architecture which considers the overall coordination of multiple regulatory resources by the energy hub operator is proposed.For the distributed optimal scheduling problem of ADN,a distributed optimal schedule architecture for regional autonomy and inter-regional coordination of ADN is built basd on the grid partition theory.For the distributed optimal control in sub-regions of ADN,a distributed control architecture oriented to the collaborative control of control unit in sub-regions of ADN is established based on the multi-agent theory.The above research results will provide a regulatory framework and operating system basis for the further research on the distributed optimal regulation of ADN.Aiming at the self-dispatching problem of the MIES connected to ADN,a self-dispatching operation strategy of the MIES which takes into account the characteristics of combined heat and power storage/supply of the advanced adiabatic compressed air energy storage(AA-CAES)is proposed.First,the system structure and operating principle of a typical MIES which contains AA-CAES are analyzed.Then,the detailed scheduling model for the applications of combined heat and power storage/supply of AA-CAES is established.On this basis,taking into account the coordinated operation of dispatching resources such as gas turbines and voltage source converters,a self-dispatching model of the studied MIES is established with the optimization goal of minimizing the system operating costs.The simulation results have verified that the proposed scheduling strategy can effectively improve the operating economy,flexibility and renewable energy consumption capacity of the micro integrated energy system containing AACAES.For the distributed optimal scheduling of ADN,a distributed optimal scheduling strategy of ADN based on the alternating direction multiplier method with dynamic step size is proposed.First,an adjustable robust scheduling model for ADN based on the improved uncertainty boundaries is established.Then,the optimization method for the conservative parameter of the robust scheduling model is proposed to optimize the economy of the scheduling strategy while maintaining its robustness.On this basis,a distributed robust optimal dispatching model of ADN is proposed based on the alternating direction multiplier method with dynamic step size considering the distributed scheduling architecture built before.Finally,the efficient solution of the proposed model is achieved through simulation examples.The simulation results verify the effectiveness of the proposed distributed optimization scheduling strategy and the conservative parameter optimization method of the robust scheduling model.For the distributed optimal control in sub-regions of ADN,a distributed optimal control strategy considering event trigger mechanism is proposed.First of all,for the power fluctuation suppression and real-time power balance of the sub-regions of ADN,a distributed coordinated control strategy based on consensus control algorithm is proposed to realize the economic allocation of active power and the proportional distribution of reactive power among the control units.On this basis,an event trigger mechanism for communication control among distributed generator agents is designed.This event trigger mechanism can realize the information exchange of control units when the system is disturbed and reduce redundant communication during stable operation of the system.Finally,simulations are carried out to verify the effectiveness of the proposed control strategy and event trigger mechanism.