Leader of work: dr.sci.tech. Kovalev Alexander Petrovich.
Research issue actuality. According to Ukraine health legislation providing of electrical safety at industrial objects is one of the most important problems in protection sphere. Analysis of MakNII statistics for the period of 1991-2007 shows that level of electric shock accidents in electrical installations over 1000 V occurred at Ukrainian mines is amount to 93% at that in cable networks – 35.5%, start-up and switch instrumentation – 37.5%, electrical motors – 20%. That's why researches, concerned with forecasting and probability of electric shock accident occurrence from different kinds of electrical equipment is actual scientific task.
Aim: formation of time dependence of electric shock on equipment condition,
crash protection system reliability, precaution period and behavior of a person; guidelines development for normalization of electrical s
afety level at electrical equipment. For the achievement of assigned tasks it is necessary to solve the following problems:
- Development of mathematical model of electric shock damage at equipment maintenance;
- Obtaining engineering formula for probability definition of electric shock damage for the case when
λi << μi; λiΘi<0.1;
- Development of structural equivalent scheme of probable cases of electric shock damage.
Using initial data and proposed mathematical model it is necessary to estimate probability of electric shock damage for the
time period t during maintenance shift.
Practical issue appliance lies in design procedure perfection that allows to define probability of electric shock occurrence at equipment maintenance and choose optimal leakage relay test terms in respect to safety.
Scientific novelty consists in development of more contemporary model of electric shock procedure that permits to estimate its average time and dispersion.
Master dissertation intended for mathematical model of electrical shock procedure development at equipment
maintenance in electrical networks under 1000 V.
In the basis of estimation of electrical safety at electrical equipment exploitation lies conception of electric shock damage as fortuitous
combination of several dangerous machinery and human elements.
At formation of mathematical model of electrical shock procedure following assumptions and statements were accepted:
- Source of damage appears every time when single-phase short circuit to ground takes place, when cores of electric
equipment under load or cable wires are unsealed;
- Electric shock damage at protection system intact is considered as rare event and is not taken into account in calculations;
- Leakage relay threat is detected only at precaution inspection.
Factors which influence on the electric shock procedure at equipment maintenance on coal mine area are also the subjects of research.