The impact of single-phase grid-connected distributed photovoltaic systems on the distribution network using P-Q and P-V models

• Published in: International journal of electrical power & energy systems 2017-10, Vol.91, p.20-33
• Main Authors: Emmanuel, Michael, Rayudu, Ramesh
• Format: Article
• Language: English
• Subjects: Equipment loading; Grid-connected; Photovoltaic; Voltage unbalance
• ISSN: 0142-0615; 1879-3517
• DOI: 10.1016/j.ijepes.2017.03.001

•Impacts of distributed single-phase PV systems have been analysed.•The performance of different DG models have been compared for the PV system.•Impacts on equipment loading, power losses and voltage unbalance have been evaluated.•PV model reduced equipment loading and power losses than the PQ model.•Under heavy load condition, the PV model performs better than the PQ model. The gradual emergence of photovoltaic (PV) systems as the most common distributed generation interconnected with the electric power system calls for a detailed power flow analysis with different models especially in the evolving unbalanced active distribution network. This paper is an extension of a previous study carried out on the performance evaluation of a 10kWp grid-connected PV system deployed in a school, with the grid providing a virtual storage and access to upstream markets. For increased adoption of such systems in the unbalanced distribution network, it is pivotal to understand the mode of operation and the type of connection to the system. This article presents an impact analysis of such utility interactive single-phase PV systems distributed on all the single-phase load nodes of the traditional IEEE-13 bus distribution test feeder. The PV distributed generation (PV-DG) can be modelled as constant P-Q or P-V nodes with varied impacts in power flow studies for the unbalanced active distribution network. Results from these models are compared in terms of their impacts on voltage profiles at load buses, voltage unbalance, equipment loading, power losses and the total number of iterations for a converged power flow solution.