Patent ID: 11959976
Assignee: SOUTH CHINA UNIVERSITY OF TECHNOLOGY
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G  H  Y | IPC G  H

Claim 2:
3. The DC converter valve state detection method based on temporal features of converter terminal currents according to claim 1, wherein the step S3 comprises:
S31. defining a ratio of the valve conducting current to the valve current base value as a valve current relative relationship SVT1, SVT2, SVT3, SVT4, SVT5 and SVT6 according to the following formula:, S
      
       V
       ⁢
       T
       ⁢
       m
      
     
     =
     
      
       i
       HVTm
      
      
       i
       
        b
        ⁢
        a
        ⁢
        s
        ⁢
        e
       
      
     
    
   
   
    
     (
     4
     )
    
   
  
 

where SVTm represents the valve current relative relationship SVT1, SVT2, SVT3, SVT4, SVT5 and SVT6, m=123456 iHVTm represents the valve conducting current, and ibase represents the valve current base value;
S32. calculating a valve current duty cycle of the valve current relative relationship SVTm through a single-phase comparator, and defining the valve current duty cycle being greater than K as the valve conducting state SVTm according to the following formula:

SHVTm=SVTm;SVTm>K  (5)

where SHVTm is the valve conducting state, and K is a critical value considering calculation errors; and
S33. according to the step S32, calculating a valve conduction time interval of the valve conducting state in each power frequency cycle with an integrator according to the following formula:

tHVTm=∫−T0SHVTmdt  (6)

where tHVTm is the valve conduction time interval, and T is the time interval of a power frequency cycle.