Research On Economic And Resilience Improvements Of Distribution Networks With Participation-in-Depth Of Distributed Energy Resources

To promote the high proportion integration of distributed energy resources(DERs),the following two problems must be addressed: 1)the economic incentives for DER installations need to be improved.The existing methods cannot fully characterize the value of DERs in providing energy,capacity,congestion mitigation,loss reduction,voltage regulation,and other electricity services in the distribution networks.These lead to low returns of DER owners and hindering DER integrations;2)the integration of high proportion DERs leads to insufficient resilience of distribution networks.The existing methods are insufficient to cope with the energy and information uncertainties brought by DER integrations and thus it is difficult to ensure the security operation of distribution networks under accident condition.To address the above issues,this thesis focuses on the following research efforts.A weakly centralized distributed trading mechanism and a calculation method of network usage charge are proposed,which guarantees the security operation of distribution network and market liberalization.A two-layer model is established,with the optimal operation of distribution network in the upper layer and distributed trading in the lower layer.The proposed iterative algorithm based on the analytical target cascading shows the interaction process among the market entities.It is shown that the proposed method can realize distributed trading while ensuring operation security of distribution network,improve the profit of DER owners,and promote the DER integrations.A distribution network planning method considering multiple entities is proposed,where the DER values can be effectively represented and the income of DER owners is improved.A three-stage planning model is established,with the first stage being the planning model of the investors,the second stage being the system security assessment of the operators,and the third stage being the optimal operation model of the operators.The proposed iterative algorithm for solving the three-stage model integrates the interaction mechanism among the market entities.This allows the DERs to participate in both energy and capacity markets and investors to compete fairly after receiving the economic incentives from the operators.It is shown that the proposed method can provide a fair and efficient market mechanism for the multientity,promote the DER integrations,and improve the economics of distribution networks.A fast service restoration for distribution networks considering energy uncertainties is proposed,which can reduce the computation time and obtain a recovery solution that ensures operation security with less load shedding than those obtained by using existing methods.The service restoration based on the stochastic response surface method is proposed to handle the uncertainties of DERs.A network topology optimization method based on improved solution space and improved fireworks algorithm is proposed,which can eliminate inferior solutions,improve the solution efficiency,and obtain the restoration scheme after faults.It is shown that the proposed method can effectively handle the uncertainties of DERs,ensure operation security,reduce the load shedding after faults with less computation time,and thus improve the operation resilience of distribution networks under fault conditions.A distributed resilience control under information uncertainty is proposed,which does not need the assumed information uncertainty model.A three-stage resilience control is proposed,including distributed resilience control,communication network reconfiguration,and local control.A distributed resilience control model based on Hinfinity theory is established,and nonlinear matrix inequalities are built and solved by the homotopy method to obtain control parameters to resist false data injection(FDI)attacks and denial-of-service(Do S)attacks.A software-defined network-based communication network reconfiguration method and control switching method are proposed,which can avoid the additional risk of being attacked due to the introduction of a software-defined network.It is shown that the proposed method can mitigate the threats posed by multiple cyberattacks to the security operation of DERs without the hypothetical models of these attacks,and improve the resilience of distribution networks under the condition of information uncertainty.