Feasibility study of power engineering secondary equipment protection methods from static electricity

The paper presents feasibility study of power engineering secondary equipment protection methods from static electricity basing on calculation and experimental procedure. Method was applied for newly constructed objects and modernized objects as well. The procedure includes calculation of expected electrostatic potential at human body considering environment characteristics (relative humidity, dimensions and electrophysical characteristics of flooring and footwear). Calculated potential was compared to acceptable value. Acceptable value represents immunity test level of secondary equipment (relay protection and automation, communication equipment, PCs) presented in standards [1], [2], [3], [4] and [5]. In calculations electrostatic charging current density j0 = 10 μA/m2 was taken as in domestic applications. Calculation result analysis showed optimal methods to limit human electrostatic charge accumulation for designed objects and objects in operation.