Patent ID: 11885843
Assignee: HITACHI ENERGY LTD
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 7:
8. The system according to claim 6, wherein the instantaneous comparison voltage value is calculated by:, {
    
      
        
          
            
              u
              
                res
                ⁢
                
                  
                
                ⁢
                _
                ⁢
                
                  
                
                ⁢
                p
                ⁢
                
                  
                
                ⁢
                1
                ⁢
                p
                ⁢
                
                  
                
                ⁢
                2
                ⁢
                
                  
                
                ⁢
                _
                ⁢
                
                  
                
                ⁢
                k
              
            
            =
            
              
                R
                ·
                
                  i
                  
                    p
                    ⁢
                    
                      
                    
                    ⁢
                    1
                    ⁢
                    p
                    ⁢
                    
                      
                    
                    ⁢
                    2
                    ⁢
                    
                      
                    
                    ⁢
                    _
                    ⁢
                    
                      
                    
                    ⁢
                    k
                  
                
              
              +
              
                L
                ·
                
                  
                    di
                    
                      p
                      ⁢
                      
                        
                      
                      ⁢
                      1
                      ⁢
                      p
                      ⁢
                      
                        
                      
                      ⁢
                      2
                      ⁢
                      _
                      ⁢
                      
                        
                      
                      ⁢
                      k
                    
                  
                  dt
                
              
            
          
        
      
      
        
          
            
              u
              
                res
                ⁢
                
                  
                
                ⁢
                _
                ⁢
                
                  
                
                ⁢
                p
                ⁢
                
                  
                
                ⁢
                1
                ⁢
                
                  
                
                ⁢
                _
                ⁢
                
                  
                
                ⁢
                k
              
            
            =
            
              
                R
                ·
                
                  (
                  
                    
                      i
                      
                        p
                        ⁢
                        
                          
                        
                        ⁢
                        1
                        ⁢
                        _
                        ⁢
                        
                          
                        
                        ⁢
                        k
                      
                    
                    +
                    
                      
                        
                          k
                          R
                        
                        ·
                        3
                      
                      ⁢
                      
                        i
                        
                          0
                          ⁢
                          
                            
                          
                          ⁢
                          _
                          ⁢
                          
                            
                          
                          ⁢
                          k
                        
                      
                    
                  
                  )
                
              
              +
              
                L
                ·
                
                  
                    d
                    ⁡
                    
                      (
                      
                        
                          i
                          
                            p
                            ⁢
                            
                              
                            
                            ⁢
                            1
                            ⁢
                            _
                            ⁢
                            
                              
                            
                            ⁢
                            k
                          
                        
                        +
                        
                          
                            
                              k
                              L
                            
                            ·
                            3
                          
                          ⁢
                          
                            i
                            
                              0
                              ⁢
                              
                                
                              
                              ⁢
                              _
                              ⁢
                              
                                
                              
                              ⁢
                              k
                            
                          
                        
                      
                      )
                    
                  
                  dt
                
              
            
          
        
      
      
        
          
            
              k
              R
            
            =
            
              
                
                  R
                  0
                
                -
                
                  R
                  1
                
              
              
                3
                ⁢
                
                  R
                  1
                
              
            
          
        
      
      
        
          
            
              k
              L
            
            =
            
              
                
                  L
                  0
                
                -
                
                  L
                  1
                
              
              
                3
                ⁢
                
                  L
                  1
                
              
            
          
        
      
    
  

wherein p1 and p2 represent the first and second phases of the three-phase transmission line of the power transmission system, ures_p1p2_k represents the instantaneous comparison voltage value between phase p1 and phase p2 at instant k, ip1p2_k represents the sampled value of the current between phase p1 and phase p2 at the measurement point at instant k, ip1_k represents the sampled value of the current of phase p1 at the measurement point at instant k, R and L, respectively, represent the resistance value of the resistor and the inductance value of the inductor in the time-domain lumped parameter model,, di
    
      p
      ⁢
      
        
      
      ⁢
      1
      ⁢
      p
      ⁢
      
        
      
      ⁢
      2
      ⁢
      _
      ⁢
      
        
      
      ⁢
      k
    
  
  dt, represents the differential value of the current ip1p2_k,, d
    ⁡
    
      (
      
        
          i
          
            p
            ⁢
            
              
            
            ⁢
            1
            ⁢
            _
            ⁢
            
              
            
            ⁢
            k
          
        
        +
        
          
            
              k
              L
            
            ·
            3
          
          ⁢
          
            i
            
              0
              ⁢
              
                
              
              ⁢
              _
              ⁢
              
                
              
              ⁢
              k
            
          
        
      
      )
    
  
  dt, represents the differential value of the value ip1_k+kL·3i0_k, R0 represents the zero sequence resistance of the three-phase transmission line, R1 represents the positive sequence resistance of the three-phase transmission line, L0 represents the zero sequence inductance of the three-phase transmission line, L1 represents the positive sequence inductance of the three-phase transmission line, and i0_k represents the zero sequence current at instant k.