Decentralized renewable energy resources have been identified as one of the promising ways to sustain the future energy demands. However, most of the energy produced by renewable energy resources, particularly the Photovoltaic (PV) system is intermittent in nature and often fluctuates. In this regard, this paper utilizes Malaysian Reference Networks model, with the aim to analyse the effects of solar PV integration with medium voltage (MV) network under various solar variability conditions. For validation, network losses and voltage profiles had been evaluated on various PV variability profiles using DIgSILENT power factory software. The impact of solar generation variability on transformer On-Load Tap Changer (OLTC) had been investigated through the utilization of five types of solar variability day in Malaysia; compiled as one-minute resolution. In addition, urban, sub-urban, and rural MV networks had been considered in this study. The results presented in this paper show that proper allocation of PV plants can help to reduce network losses and improve voltage profiles. Rural network incurred the highest number of tap changes in OLTC to control the voltage level, compared to urban and sub-urban networks.