From the analysis of four 2.5 MVA transformers in the solar plant in the time span of 1 year, it has been found that the PV has huge impact on the transformer performance, which is influenced by the load on transformer, the level of PV penetration and the rating of transformers.
Energy policies worldwide are mandating large-scale integration of solar panel (SP) generators with inverters on distribution systems. This causes several SPs to be connected to a distribution transformer. The SP and its interfacing inverter alter the performance characteristics of the transformer.
But the harmonics effects caused by the solar panel have negative impact on performance of transformers. Reversal of power is also one of the negative impacts of PV penetration. Furthermore, the frequency of working of OLTC increased by 45% due to solar integration, which may increase the risk of failure of transformers.
A PV plant has various impacts on performance parameters of transformers. The working of on-load tap changer is also affected by the presence of PV. The main cause behind the altered performance of transformer in the presence of solar panel is its associated inverters that are used to supply linear loads.
It discussed the impact of solar panel on the distribution system and transformer and concluded that as the number of PV panels increases, distortion in voltage and current increases, as does the losses and the temperature. The effect of solar panel on the transformer sizing is obtained by the Freitas et al. ( 2018) in 2015.
The study shows that the ageing of the transformer may be reduced if continuous solar power is generated—as from the data given in Table 9, \ ( F_ {aa} \) reduces by 70% with the installation of solar panel. The negative effect of solar panel on the transformer can be found in terms of harmonics and the OLTC.