A Calculation Method for PVs’ Safe and Economic Carrying Capacity that Consider Transmission and Distributed Network Coordination

[Objective] In view of the problem that the traditional calculation method for distributed photovoltaic （PV） capacity cannot comprehensively consider the energy absorption capacity of the transmission network and the operational safety of network equipment， this study proposes a method for constructing and optimally solving the distributed PV capacity interval considering the coordination between the transmission and distribution networks. [Methods] First， at the transmission network level， considering different provincial new energy utilization rates and energy storage configuration ratios， the distributed PV capacity interval was constructed based on a time-series simulation of production. Subsequently， at the distribution network level， to optimize the investment economy of the distribution network， a method for optimally solving the distributed PV capacity and checking the interval was proposed， considering the power flow of transmission and distribution networks， power quality， and energy storage charging and discharging constraints. Finally， case studies were conducted in provinces of different regions in China. [Results] The results show that the distributed PV capacity interval and the optimal solution of the distributed PV capacity can constrain each other， which can meet both the new energy absorption demand of the transmission network and the reliable operation demand of the transmission and distribution networks. [Conclusions] The proposed method incorporates distributed PV into the provincial supply-demand calculation， considers the impact of the absorption space of all power sources on capacity calculation， scientifically evaluates the accessible margin of the power grid， and provides an important reference for guiding the rational layout of distributed PV.