Coordinated Acitve-reactive Power Optimization Operation Method of Distribution Network with Distributed Flexible Resource Access

Photovoltaic（PV） and energy storage system（ESS） are important distributed flexible resources, can provide active and reactive power support for the distribution network, and a coordinated active-reactive power optimization operation method is proposed for the distribution network in combination with traditional reactive power optimization, which achieve the improvement of distribution network economy and stability. Firstly, the active and reactive power regulation capabilities of PV and ESS are fully considered, and an active-reactive distributed flexible resource model is established. Then, the active and reactive power coordinated optimization model of the distribution network is constructed with the optimization objective of minimising the total operating cost of the system. Among them, for the nonlinear term of the discrete reactive power optimisation device, the exact linear relaxation method is used to linearise it, and at the same time, in order to improve the model solution efficiency, the second-order cone constraints are “ε-relaxed” to realise the model from the mixed integer second-order cone programming（MISOCP） to mixed integer linear programming（MILP）. Finally, a case analysis is carried out on the improved IEEE 33 nodes system, and the results show that the proposed method can fully exploit the active and reactive power regulation capabilities of PV and ESS, effectively reduce the system operating cost and improve the reactive power regulation margin, and at the same time, it is verified that the MILP can effectively improve the model solving efficiency under the premise of guaranteeing the solving accuracy.