Shevchenko O. Forecasting and prevention of danger of ignition in electrical networks of industrial and household objects.

The object - system of electrosupply, automatic switch, device of protective switching-off. The purpose - improvement of methods of estimation and forecasting of danger of ignition in electrical networks, development of new means of protection allowing to reduce number of fires from the spark discharges. Methods of research: the theory of probabilities, reliability, statistical methods. Scientific importance: the new mathematical model of forecasting of danger of ignition in electrical posting is developed; first the analytical dependencies of frequency of occurrence of ignitions on frequency of occurrence and duration of existence of short circuit currents, reliability of switching devices and terms of their preventive maintenance are established; the new mathematical model of the relay for spark protection is offered. Practical results: a technique of forecasting of danger of ignitions in electrical networks; The basic norms of reliability of protective switching devices and terms of their preventive maintenance, at which is provided normalized level of safety of a network; development of the requirements to the relay for spark protection and its basic circuits. A degree of introduction: mathematical model and formulas are accepted in a basis of four normative documents, the laboratory sample of the relay for spark protection is made. The results of work are expedient for using by UkrNIIPB of Ukraine for development of a technique of estimation of danger of ignition in network units, UrkNIIVE when designing of means of protection and determining its norms of reliability.