The last decade has seen an immense growth in solar PV systems (both large-scale solar PV systems and distributed solar PV systems). It is expected that this growth will continue due to environmental concerns. Since conventional generators are defined by their physics and control, and solar PV systems are defined solely by their control algorithms, this transition has brought with it challenges for preservation of power system stability. Presently, solar PV systems are not modelled in detail in the current dynamic grid model of TenneT. However, due to the flourishing of solar PV systems and lessening of synchronous generators, the role of solar PV systems on the dynamic behaviour of power systems keeps increasing hence an increased need for detailed modelling is necessary. In this thesis report, solar PV systems i.e. large-scale solar PV systems and aggregation of distributed solar PV systems, are modelled according to the requirements of the Dutch gridcode (netcode) and the European 'Requirements for Generators'. Additionally, a standard modelling approach, including proper selection of models and a default parameter set, for representation of large-scale and aggregated PV systems is developed. Following this, the analysis of transient- and voltage stability is firstly conducted on an IEEE 9 bus network with different PV penetration levels. In addition, several case studies are selected based on TenneT's investment plan scenario to determine the impact of a high penetration of PV systems on transient- and voltage stability in a larger, more extensive network.