A test system with wide frequency response designed to measure pulse shape of partial discharge was introduced in this paper.The measuring impedance was tested by square wave with very steep trailing edge and the corona in air under DC voltage was detected

all of which proved the whole system meet the specification.According to the analysis of defects in oil-paper insulation of the converter transformer

five corresponding PD models were designed.With using the UWB detection system

plenty of the PD pulses were obtained to get the typical pulse shapes in oil-paper insulation under DC voltage.The results show that the PD pulse shapes of the defects in oil under DC voltage are non-oscillatory

and have no overshoot.The feature parameters of the pulse shapes extracted by shape in time domain

self-correlation

AR model and Renyi information methods differ with different discharge models.All these will be help for the research of the mechanism of PD in oil-paper insulation system

the spectral characteristic of on-filed monitoring system and the identification of different PD pulse shapes under DC voltage.