To provide a reference for the selection of measurement parameters in on-line monitoring system of electrical equipment based on Brillouin optical fiber distributed sensing

the pseudo-Voigt model and the noise model are validated by the measured Brillouin spectra with different incident light pulse widths and average times. Thereafter

on the basis of considering the deviation of frequency sweep span

the influences of frequency sweep span deviation

frequency sweep span

linewidth

signal-to-noise ratio

number of sweeps and ratio of gain peak value on the Brillouin frequency shift error are systematically investigated based on a large number of numerically generated and measured Brillouin spectra. The results reveal that the Brillouin frequency shift error increases with increasing deviation of frequency sweep span and the acceleration also increases with it. If the number of sweeps is fixed

the Brillouin frequency shift error decreases first and then increases as the frequency sweep span increases. If the frequency sweep span ranges from 1.5 to 3 line widths

the error will negligibly change. If the number of sweeps and the ratio of frequency sweep span to line width are fixed

the Brillouin frequency shift error is proportional to line width. If the frequency step and the ratio of frequency sweep span to line width are fixed

the Brillouin frequency shift error is proportional to line width. The Brillouin frequency shift error reduces exponentially with signal-to-noise ratio increasing. If the ratio of frequency sweep span to the line width is fixed

the Brillouin frequency shift error reduces as a power of number of sweeps. The Brillouin spectrum shape has no remarkable influence on the Brillouin frequency shift error. Finally

the suggestions for the selection of measurement parameters in on-line monitoring system of electrical equipment based on Brillouin optical fiber distributed sensing are discussed.