FIELD: measurement of equivalent insulation resistance of power networks. SUBSTANCE: measurement technique is based on alternate shorting-out of network poles by means of resistor, sequential measurement of instant voltages across this resistor at moment of shorting-out, and determination of equivalent insulation resistance values at equal time intervals as product of shorting-out resistor value by ratio of voltage of network under test to sum of steady-state voltage across shorting-out resistor reduced by one. When measuring instant voltages across shorting-out resistor, end-of-measurement moment is noted; to this end, differences between adjacent values of first three results of instant voltage measurement are determined, difference between results obtained ΔUij are found, and compared by modulo with first desired threshold ΔVth.; when this threshold is exceeded, measurements are ceased and when this value is below ΔVth., difference between last measurement result of instant voltage is compared by modulo with voltage at shorting-out moment with second desired threshold ΔVth. multiplied by number of time intervals; at value below second threshold ΔVth., measurements are ceased and last result of instant voltage measurement is considered as steady-state voltage; otherwise, measurements of voltage across shorting-out resistor are continued, but comparison is made between measurement results taken through double, triple, etc. time intervals until one of above-mentioned conditions is satisfied. EFFECT: improved measurement accuracy. 5 dwg
