The integration of photovoltaic (PV) systems into power grids has become a popular way to provide sustainable, low-cost energy. However, the lack of internal inertia in PV systems, as well as the continuous operation of PV plants at maximum power point, might pose challenges for grid stability and frequency control. The commonly employed method to participate in the frequency control is to operate the PV plant in a deloading mode at reduced power. As a result, a virtual inertial and primary frequency control can be provided. However, operation in a deloading mode may require complex algorithm and sensors for irradiation and temperature measurement. In addition, the virtual inertia reliability is dependent on power electronics, processors, and control. This paper presents two alternative techniques for dealing with frequency control. The first one combines simplicity and the absence of irradiance and temperature sensors by using a novel power reserve control (PRC) technique based on PV voltage variation. It has a two-mode cycle, with the first mode being used to calculate and reach the MPPT point and the second mode being used to provide the appropriate power reserve. The cycle continues in PRC mode until a triggering event is generated by an implanted device that captures the PV system’s voltage change. In this study, the PRC approach is applied to offer primary frequency control (PFC) and virtual inertia (VIC). The second technique addresses the lack of real rotational inertia in PV systems. In this paper, we suggest incorporating a synchronous generator into the PV plant without providing active power. Its main role is to offer an intrinsic real inertial response. In addition, a hybrid approach based on virtual and real inertial response is investigated and discussed. To model and simulate the entire system in an isolated and interconnected power grid, Matlab software is employed. Both proposed approaches are tested and validated in the presence of climate changes and large perturbations affecting the grid.