The method of determining characteristics of elements for over-voltage protection of low-voltage systems

The aim of this work is to develop an original method and equipment for testing and characterization of relevant characteristics of non-linear over-voltage protection elements on low-voltage level. The equipment we have constructed and our original method enables us to reliably and quickly record volt-ampere characteristics, volt-ohmic characteristics, coefficient of non-linearity, and characteristics of breakdown voltages of over-voltage diodes and varistors. Impulse characteristics of the gas filled surge arresters (GFSA) were determined by using the surface law thus the obtaining of impulse characteristics of GFSA was considerable speeded up. Using this method one can determine the characteristics more precisely, since there is no possibility of making an error due to warning up of the analyzed element, caused by longer impact of electric current. A statistical method for analyses measurements result was also developed and presented in this work. Results obtained by these method are comparable to results obtained by classical methods.