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 1:
2. The DC converter valve state detection method based on temporal features of converter terminal currents according to claim 1, wherein the step S2 comprises:
S21. obtaining valve currents iVT1, iVT2, iVT3, iVT4, iVT5 and iVT6 of the valve VT1, the valve VT2, the valve VT3, the valve VT4, the valve VT5, and the valve VT6 by calculating absolute values of the three-phase AC currents ia, ib and ic according to the following formula:, {
     
      
       
        
         
          
           i
           
            VT
            ⁢
            1
           
          
          =
          
           
            ❘
            "\[LeftBracketingBar]"
           
           
            i
            a
           
           
            ❘
            "\[RightBracketingBar]"
           
          
         
         ;
         
          
           i
           a
          
          <
          0
         
        
       
      
      
       
        
         
          
           i
           
            VT
            ⁢
            2
           
          
          =
          
           
            ❘
            "\[LeftBracketingBar]"
           
           
            i
            c
           
           
            ❘
            "\[RightBracketingBar]"
           
          
         
         ;
         
          
           i
           c
          
          >
          0
         
        
       
      
      
       
        
         
          
           i
           
            VT
            ⁢
            3
           
          
          =
          
           
            ❘
            "\[LeftBracketingBar]"
           
           
            i
            b
           
           
            ❘
            "\[RightBracketingBar]"
           
          
         
         ;
         
          
           i
           b
          
          <
          0
         
        
       
      
      
       
        
         
          
           i
           
            VT
            ⁢
            4
           
          
          =
          
           
            ❘
            "\[LeftBracketingBar]"
           
           
            i
            a
           
           
            ❘
            "\[RightBracketingBar]"
           
          
         
         ;
         
          
           i
           a
          
          >
          0
         
        
       
      
      
       
        
         
          
           i
           
            VT
            ⁢
            5
           
          
          =
          
           
            ❘
            "\[LeftBracketingBar]"
           
           
            i
            c
           
           
            ❘
            "\[RightBracketingBar]"
           
          
         
         ;
         
          
           i
           c
          
          <
          0
         
        
       
      
      
       
        
         
          
           i
           
            VT
            ⁢
            6
           
          
          =
          
           
            ❘
            "\[LeftBracketingBar]"
           
           
            i
            b
           
           
            ❘
            "\[RightBracketingBar]"
           
          
         
         ;
         
          
           i
           b
          
          >
          0
         
        
       
      
     
    
   
   
    
     (
     1
     )
    
   
  
 

where iVT1 is the valve current of the valve VT1, iVT2 is the valve current of the valve VT2, iVT3 is the valve current of the valve VT3, iVT4 is the valve current of the valve VT4, iVT5 is the valve current of the valve VT5, and iVT6 is the valve current of the valve VT6;
S22. calculating a maximum value of the absolute values of the three-phase AC currents ia, ib and ic as the valve current base value according to the following formula:, i
      
       b
       ⁢
       a
       ⁢
       s
       ⁢
       e
      
     
     =
     
      
       max
       ⁡
       (
       
        
         
          ❘
          "\[LeftBracketingBar]"
         
         
          i
          a
         
         
          ❘
          "\[RightBracketingBar]"
         
        
        ,
        
         
          ❘
          "\[LeftBracketingBar]"
         
         
          i
          b
         
         
          ❘
          "\[RightBracketingBar]"
         
        
        ,
        
         
          ❘
          "\[LeftBracketingBar]"
         
         
          i
          c
         
         
          ❘
          "\[RightBracketingBar]"
         
        
       
       )
      
      2
     
    
   
   
    
     (
     2
     )
    
   
  
 

where ibase presents the valve current base value, |ia|, |ib| and |ic| represent the absolute values of the three-phase AC currents, and max(|ia|,|ib|,|ic|) represents the maximum value of the absolute values of the three-phase AC currents; and
S23. defining the valve current being greater than the valve current base value as the valve conducting current according to the following formula:

iHVTm=iVTm;iVTm≥ibase  (3)

where m=123456, and iHVTm represents the valve conducting current.