Enhancing the Transient Stability of PV-Hydro Microgrid using Virtual Synchronous Machine (VSM)

Abstract

Renewable energy sources such as solar, wind, and biomass are being integrated into electrical networks in order to meet demand while reducing dependency on non-renewable sources such as petroleum products, coal, and natural gas are attracting a great deal of attention. The bulk of distributed generators (DGs) are linked to the utility grid through power electronics-based converters, which have either extremely little or no spinning mass and damping property, reducing total system inertia and transient stability. It would cause a significant change in the frequency of the system if large load changes in the system. This may be improved by using a Virtual Synchronous Machine (VSM) to simulate the inertial and damping properties of a real generator. A VSM is a power electronics device that stores short-term energy and has a dispatching mechanism that allows it to operate like a synchronous generator. VSM simulates the inertial and damping qualities of a synchronous machine, and it may either inject or absorb power into or from the grid in a manner similar to the injection or absorption of kinetic energy in synchronous generators. This study investigates the possibility of using VSM to increase grid stability under transient conditions. Unlike many previous efforts, this study proposes a way of regulating VSM operation utilizing power angle control. An angle controller is built using a small signal model of the swing equation that is linearized round the operating point. The suggested power angle control method has been implemented in the VSM and the system was simulated in MATLAB/Simulink. A system under this study considers the hydro of 150kVA capacity which has been connected with the PV of 10 kW. The substantial load is switched on so that the frequency deviation increases beyond the normal range. The transient stability was then improved by implementing the VSM by improving the frequency deviation from 19% to 7%.