A Co-Simulation Platform for Microgrid Integration into Transmission System - Power Quality Study

Microgrids open up a new arena of power generation, distribution, and consumption. Microgrids have the ability to deliver reliable and clean power. It enhances grid reliability through its ability to isolate from the utility grid under any abnormal conditions and work in standalone mode, then reconnect and synchronize again with the grid without load interruption. The growing installation of renewable energy resources creates higher interactions between transmission and distribution systems, which increases fears of the impact of power electronics devices on the stability and power quality metrics of the utility grid. Such studies require complete modeling and simulation of the power electronics interfacing microgrids with the power system. This paper presents a co-simulation framework for a microgrid connection with a transmission system. The framework uses Power System Simulator for Engineering (PSS/E) as a power system analysis tool and electromagnetic transient simulator (PSCAD) which is used to model the microgrid system and its control. The paper also investigates the impact of a large-scale microgrid on the power quality of the grid network. The total harmonic distortion (THD) in the current and voltage at the point of common coupling (PCC) is investigated and the obtained results are compared with the limits specified by the international standards. The co-simulation results are aimed to show that the inclusion of Distributed Energy Resources (DERs) in the transmission system works within the allowed limits and standards.