A Techno-Economic Approach for Increasing the Connectivity of Photovoltaic Distributed Generators

Abstract

High penetration of distributed generation (DG) results in technical problems as voltage rise, voltage unbalance, substation reverse power, and transformer overloading. These problems adversely affect the connectivity of DGs either in the planning stage by decreasing the number of connected DGs, or in the operation stage by applying DGs' active power curtailment (APC). This paper presents a techno-economic approach for the enhancement of photovoltaic (PV) DGs connectivity. The proposed approach first employs a probabilistic economic technique for determining the non-curtailable portion of the PV DG power that ensures profitable DG investment. This portion is integrated, as an economic constraint, in the planning phase of the proposed approach that aims to maximize the number of PV DGs connected to the system. In the operation phase, the proposed approach utilizes the capabilities of the existing equipment on the system, i.e., regulators, capacitors, DGs reactive power, and DGs APC to mitigate all technical problems. The overall objective of this stage is to minimize the total DGs APC while fulfilling all technical and economic constraints. The proposed approach is tested on the modified IEEE 123-bus feeder. The results clarify the efficiency of the proposed techniques in increasing the connectivity of PV DGs while maintaining profitable DG project.