Patent ID: 11892495
Assignee: LS ELECTRIC CO., LTD.
Field: Measurement (Instruments)
Classification: CPC G | IPC G  H

Claim 17:
18. The insulation monitoring device of claim 17, wherein the control unit is configured to terminate the primary tuning when the difference between the first average voltage and the second average voltage is equal to or less than the preset first error as a result of the primary tuning,
determine at least one reference point based on a starting time point of the primary tuning, the initial sampling interval, and a termination time point of the primary tuning, and calculate a plurality of voltage slopes based on a voltage difference between voltages according to the determined at least one reference point, and
calculate a time constant based on a slope ratio according to the calculated voltage slopes, and determine the idle time based on the calculated time constant,
determine whether the time constant is calculated according to a result of comparing the calculated slope ratio with the preset threshold value, and
when the time constant is not calculated according to the comparison result, calculate the time constant according to an operation result of a natural logarithm (ln) with respect to a preset minimum slope ratio and a time interval between a starting time point of the primary tuning and a point of time that the initial sampling interval has elapsed from the starting time point.