CONTROL METHOD OF ELECTRICAL RESISTANCE OF INSULATION AND PROTECTIVE DISCONNECTION OF ELECTRICAL EQUIPMENT Russian patent published in 2011 - IPC G01R27/18 

FIELD: electricity.

SUBSTANCE: method is based on measurement of leakage current from auxiliary source of measuring voltage in the form of periodic sequence of pulses; measurement of leakage current I₁ in time range T<t≤2T and leakage current I₂ in range 3T<t≤4T by integration of voltage drop on reference resistance over a period of supply mains, calculation of insulation resistance by formula recording of n last values of insulation resistance; calculation as per these values of expected values of insulation resistance in the current measurement range r_e and further range comparison of values r_ins, r_e, with allowable range R₀ and in case r_ins<R₀; r_e<R₀ disconnection of electrical equipment; in case r_ins<R₀; r_e>R₀ repeated comparison in the next range and in case of repetition of the case r_ins<R₀ the disconnection of electrical equipment.

EFFECT: increasing quick action of monitoring of insulation and reliability of protection of electrical equipment.

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