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

Claim 2:
3. The method according to claim 1, wherein the instantaneous comparison voltage value is calculated by:, {
    
      
        
          
            
              u
              
                
                  q
                  ⁢
                  _
                  ⁢
                  p
                  ⁢
                  1
                  ⁢
                  p
                  ⁢
                  2
                
                ⁢
                
                  _
                  ⁢
                  k
                
              
            
            =
            
              
                u
                
                  p
                  ⁢
                  1
                  ⁢
                  p
                  ⁢
                  2_
                  ⁢
                  k
                
              
              -
              
                (
                
                  
                    R
                    ·
                    
                      i
                      
                        p
                        ⁢
                        1
                        ⁢
                        p
                        ⁢
                        2_
                        ⁢
                        k
                      
                    
                  
                  +
                  
                    L
                    ·
                    
                      
                        di
                        
                          p
                          ⁢
                          1
                          ⁢
                          p
                          ⁢
                          2_
                          ⁢
                          k
                        
                      
                      dt
                    
                  
                
                )
              
            
          
        
      
      
        
          
            
              u
              
                
                  q
                  ⁢
                  _
                  ⁢
                  p
                  ⁢
                  1
                
                ⁢
                
                  _
                  ⁢
                  k
                
              
            
            =
            
              
                u
                
                  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, respectively, 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.