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

Claim 11:
12. The insulation monitoring device of claim 9, wherein the control unit is
configured to:
calculate the time constant according to whether the calculated slope ratio is equal to or greater than a preset threshold value, and
reset the initial sampling interval based on the calculated time constant and Equation below when the time constant is calculated, to perform the second tuning process based on the reset initial sampling interval,
perform the second tuning process based on the initial sampling interval when the time constant is not calculated according to a result of comparing the calculated slope ratio and the threshold value, and
when the calculated slope ratio is less than the preset threshold value, calculate a 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 the starting time point of the primary tuning and a point of time that the initial sampling interval has elapsed from the starting time point

tn=−ln(1−0.01)×τ  [Equation]

where tn denotes the reset initial sampling interval and τ denotes the time constant.