Simulator of UHF Signal of the Partial Discharge

Nuclear power plants are one of the largest producers of electricity. To remotely transmit this energy, they use the transformation of electrical voltage to higher levels using power transformers. Decommissioning such a transformer result in very high financial losses. One of the influences affecting the life and function of transformers is the activity of so-called partial discharges (PD). One of the electrical allocutions of partial discharges is the emission of broadband electromagnetic signals in the ultra-high frequency (UHF) band. This specific manifestation of partial discharge is used by the UHF method of partial discharge detection, which is very useful in terms of evaluating the state of insulation. In this paper we present methods for simulating partial discharges in transformer oil. Very thin cannulas and gas with lower electrical strength than air was used to develop the bubbles to reduce the voltage required to form PD. A simulation device for the generation of partial discharges has been proposed, realized in a vessel filled with transformer oil, in which gas bubbles with lower electrical strength are formed, in which the discharge activity will be initiated by means of electrodes with a spherical cross-section. This arrangement is supplemented by measuring apparatus for sensing, recording and subsequent analysis of signals emitted by PD. In the simulation program Ansys Maxwell, simulations of the gas bubble between the electrodes in the transformer oil were performed. The work also deals with the comparison of the achieved results for different antennas in the time and frequency domain.