Synchronous Generator Stability Investigation in Power System with High-Penetration Photovoltaics Under Varying Solar Irradiances

This study aims to analyze the stability response of the synchronous generators that work in parallel with photovoltaic (PV) power plants in a power system. The synchronous generator stability aspects measured are: rotor angle, rotor speed, active and reactive power, terminal current response, excitation current response in the generator, and PV generator responses. All aspects of the stability are simulated based on six conditions of daily solar irradiation, namely 200 W/m2, 400 W/m2, 600 W/m2, 800 W/m2, 1000 W/m2, and the condition of the power system without PV generation. The non-battery PV generator of 10 MWp connected with a transmission line uses an inverter in one of the substations. This research on electricity transmission lines is modeled in a single-line diagram of 7-buses. The existing transmission lines are supplied from two synchronous generator capacities, 100 MVA and 25 MVA. This result of this study shows that the high-penetration level of PV generator is able to increase the attenuation of the power oscillations in the synchronous generators. However, the high-penetration of the PV power is depended on the level of the solar irradiances affecting on any change of the synchronous generator stability.