FIELD: control and measuring equipment.
SUBSTANCE: invention can be used to determine the initial stage of insulation breakdown to the housing (ground) and to control its development in the existing three-phase electric network with isolated neutral. A voltage sensor with high internal resistance is connected between one of the phases of the network and the housing — ground. Another voltage sensor is connected between the mains phase to which the first sensor is connected and to one of the other two phases. Signals proportional to voltages continuously measured by said sensors are converted into digital signals, from which signals of the first harmonics are extracted. Instantaneous values and vectors of signals of the first harmonics are used to identify states of breakdown of insulation of the network.
EFFECT: determination of the initial stage of insulation breakdown and control of its development to the final stage of its breakdown to the housing — ground in the operating three-phase electric network with isolated neutral.
1 cl, 4 dwg
