In the future power grid scenario, large-scale renewable energy based power plant will be one of the main generations. Among renewable based power plant types, large-scale photovoltaic (PV) plant becoming more popular as they could provide zero-emission and sustainable energy. However, even though PV plants could contribute a positive impact on the environment, they could also contribute negatively to the power system. Large-scale PV generation came with a different dynamic and zero inertia characteristic due to the application of the power electronics devices. Furthermore, the PV plant has also a drawback in terms of intermittent power output due to the uncertainty of the sources. Those handicaps could deteriorate the stability performance of the power system especially oscillatory stability. Adding a power system stabilizer (PSS) to the systems is one of the ways for handling the oscillatory stability. However, with the integration of PV plants in the systems, PSS alone is not enough to handle the oscillatory problems coming from various sources such us from PV plant dynamic. Hence, utilizing wide-area power oscillation damping (POD) as a PV plant additional controller is inevitable. Hence, this paper proposed simultaneous parameter tuning between PSS and wide-area POD in PV plant using an imperialist competitive algorithm as the optimization method. The two-area power system is used to evaluate the performance of PSS and POD using FPA. From the results, it is found that the proposed method could enhance the oscillatory stability of the systems.