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

Claim 18:
19. The insulation monitoring device of claim 18, wherein the control unit is configured to:
determine whether the time constant is calculated according to a result of comparing the calculated slope ratio with a preset threshold value, and
further calculate a value of leakage capacitance according Equation below based on the calculated time constant when the insulation resistance is calculated according to a steady-state voltage detected after the idle time determined according to the time constant has elapsed, C
      e
     
     =
     
      τ
      
       (
       
        
         R
         e
        
        ⁢
        
         
         
          R
          i
         
        
       
       )
      
     
    
   
   
    
     [
     Equation
     ]
    
   
  
 

where τ denotes the time constant, Re denotes a value of the insulation resistance, Ri denotes a value of internal resistance of the insulation monitoring device, and the threshold value denotes a minimum value of a calculation range in which the leakage capacitance can be calculated.