Maximizing Hosting Capacity of Uncertain Photovoltaics by Coordinated Management of OLTC, VAr Sources and Stochastic EVs

Abstract

The interest in maximizing the hosting capacity of photovoltaics is recently being enlarged globally. This paper proposes a novel stochastic approach for maximizing the hosting capacity of photovoltaics in distribution systems. The proposed approach is based on a coordinated management scheme of control devices in distribution systems, i.e. transformer taps and VAr sources. It also considers the promising electrical vehicles with their stochastic nature and comprehensive model, including the arriving and departing times, and initial and preset conditions of their batteries state of charge. Further, the planning model of photovoltaics considers the reactive power support of the photovoltaic inverter based on the recently released IEEE 1547:2018 standard. Compared to existing approaches, the unique merit of the proposed approach is its ability to maximize the hosting capacity of photovoltaics by simultaneous optimization of the different control variables. To accurately solve this stochastic optimization model, a double-layer metaheuristic optimizer is developed for maximizing the hosting capacity of photovoltaics and addressing all constraints. The inner level of the optimizer optimizes the charging/discharging power of electric vehicles, transformer taps, and reactive power support while the outer one maximizes the sizes of photovoltaics. To assess the effectiveness of the proposed approach, various scenarios are performed on the IEEE 69-bus distribution system. The proposed approach can maximize the hosting capacity of photovoltaics while optimally managing transformers, VAr sources, and electric vehicles in a coordinated manner.