Behavior of a 10kVA Single-Phase Dry Transformer Under Diverse Lightning Impulses: A Simulation Approach

This paper presents a simulation-based model of a 10 kVA, 33 kV/415 V, single-phase dry transformer subjected to standard as well as non-standard lightning impulse voltages. The analysis of the transformer's subsequent responses is then described. Dry-type transformers are known for their safety, low maintenance requirements, lack of pollution, ease of installation, environmental friendliness, and fire protection features. However, non-standard lightning impulse voltages can have a detrimental impact on electrical insulation. For this reason, electrical equipment typically undergoes a lightning impulse voltage test using a standardized waveform (1.2 × 50 μs) after manufacturing. Recognizing that real-world lightning strikes often deviate from this standard waveform, a simulation model of a real-life 10 kVA, 33 kV/415 V single-phase dry transformer was developed to understand the behaviour of insulation under non-standard impulse voltages. This model was then used to analyze the transformer's response to both standard (SLI) and non-standard lightning impulse (NSLI) waveforms.