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In cases, when there are electrically weak areas in solid dielectric materials (most often gaseous or liquid inclusions), partial discharges (PD) can be measured when voltage is applied. Partial discharges cause degradation in insulated materials. The investigation of insulated material behavior under electrical stress and the data obtained from PD measurements provide the possibility to predict dielectric breakdown. PD measurements are affected by electrode arrangements and by measuring circuits (MC). It is very important to investigate the relation between experimental PD data, electrode arrangement and the elements of measuring circuits applying computer mode Is The present paper considers PD behavior of polyethylene voids. Various models have been built using special software tools for analogue design and simulation. The results obtained have been analyzed and discussed i n order to assess the influence of various types of measurement circuits. The data obtained from the model have been compared with the experimental results from polyethylene samples with artificially introduced cylindrical voids subjected to PD. The electrode configuration used is plane-plane, and electrodes are parallel to the cylinder ends of the void. The parameters of the models correspond to the parameters of the experimental set-up.

An approach is proposed to automatic testing of analog electronic circuits using PSpice-like general purpose circuit simulators based on parameterized models of the faulty elements. Using time domain response parameters that well characterize the faults, the set of typical faulty variants of the circuit is simulated. Using post-processing of the obtained results and macro-definitions in the graphical analyzer Probe, a diagnosis of parametric faults in the circuit is performed. The models of the faulty elements are defined in the form of parameterized library components for the Cadence PSpice simulator. Examples are given illustrating the proposed approach.

In the present paper, a generalized SPICE simulation model of photovoltaic modules is developed, valid for operating conditions of solar irradiance and temperature different from nominal conditions. An extraction procedure for model parameter determination is proposed using datasheet characteristics of the modules. In order to improve the model accuracy, the values of the voltage V mp and the current I mp corresponding to the maximum power point MPPT, are also used as input data. The computer realization is performed in the Cadence Capture and Cadence PSpice environment. The description of the computer model is presented. The verification of the developed SPICE simulation model of PV modules confirms its validity and accuracy.

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