Patent ID: 11888419
Assignee: JIANGSU UNIVERSITY
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 1:
2. The unified open-circuit fault-tolerant control method according to claim 1, wherein step 2) is implemented as follows, wherein
a magnetomotive force (MMF) of the five-phase permanent magnet fault-tolerant motor under normal operation is expressed as follows:

MMF1=NiA+ηNiB+η2NiC+η3NiD+η4NiE 

wherein, η=cos γ+j sin γ; N is a number of winding turns; iA, iB, iC, iD, and iE are currents of phases A, B, C, D, and E of the motor under normal operation;
when the phase A is open-circuited, the current of the faulty phase A is zero, so the MMF of the five-phase permanent magnet fault-tolerant motor is expressed as follows:

MMF2=ηNiB1+η2NiC1+η3NiD1+η4NiE1 

wherein, iB1, iC1, iD1, and iE1 are currents of the phases B, C, D, and E when the phase A is faulty;
based on a principle of equal MMF before and after the fault and equal fault-tolerant current amplitude and in consideration of the third harmonic current, current distribution of non-faulty phases except for the phase A is derived:, [
    
     
      
       
        i
        
         B
         ⁢
         1
        
       
      
     
     
      
       
        i
        
         C
         ⁢
         1
        
       
      
     
     
      
       
        i
        
         D
         ⁢
         1
        
       
      
     
     
      
       
        i
        
         E
         ⁢
         1
        
       
      
     
    
    ]
   
   =
   
    
     T
     p
    
    [
    
     
      
       
        i
        
         d
         ⁢
         1
        
        *
       
      
     
     
      
       
        i
        
         q
         ⁢
         1
        
        *
       
      
     
     
      
       
        i
        
         d
         ⁢
         3
        
        *
       
      
     
     
      
       
        i
        
         q
         ⁢
         3
        
        *
       
      
     
    
    ]
   
  
 

 
  wherein
  ,
   
  
   
    
     T
     p
    
    =
    
     1.38
     
      2
      [
      
       
        
         
          sin
          ⁢
            
          
           (
           
            θ
            -
            
             γ
             2
            
           
           )
          
         
        
        
         
          cos
          ⁢
            
          
           (
           
            θ
            -
            
             γ
             2
            
           
           )
          
         
        
        
         
          sin
          ⁢
            
          
           (
           
            
             3
             ⁢
             θ
            
            +
            γ
           
           )
          
         
        
        
         
          cos
          ⁢
            
          
           (
           
            
             3
             ⁢
             θ
            
            +
            γ
           
           )
          
         
        
       
       
        
         
          sin
          ⁢
            
          
           (
           
            θ
            -
            
             2
             ⁢
             γ
            
           
           )
          
         
        
        
         
          cos
          ⁢
            
          
           (
           
            θ
            -
            
             2
             ⁢
             γ
            
           
           )
          
         
        
        
         
          sin
          ⁢
            
          
           (
           
            
             3
             ⁢
             θ
            
            +
            
             4
             ⁢
             γ
            
           
           )
          
         
        
        
         
          cos
          ⁢
            
          
           (
           
            
             3
             ⁢
             θ
            
            +
            
             4
             ⁢
             γ
            
           
           )
          
         
        
       
       
        
         
          sin
          ⁢
            
          
           (
           
            θ
            +
            
             2
             ⁢
             γ
            
           
           )
          
         
        
        
         
          cos
          ⁢
            
          
           (
           
            θ
            +
            
             2
             ⁢
             γ
            
           
           )
          
         
        
        
         
          sin
          ⁢
            
          
           (
           
            
             3
             ⁢
             θ
            
            -
            
             4
             ⁢
             γ
            
           
           )
          
         
        
        
         
          cos
          ⁢
            
          
           (
           
            
             3
             ⁢
             θ
            
            -
            
             4
             ⁢
             γ
            
           
           )
          
         
        
       
       
        
         
          sin
          ⁢
            
          
           (
           
            θ
            +
            
             γ
             2
            
           
           )
          
         
        
        
         
          cos
          ⁢
            
          
           (
           
            θ
            +
            
             γ
             2
            
           
           )
          
         
        
        
         
          sin
          ⁢
            
          
           (
           
            
             3
             ⁢
             θ
            
            -
            γ
           
           )
          
         
        
        
         
          cos
          ⁢
            
          
           (
           
            
             3
             ⁢
             θ
            
            -
            γ
           
           )
          
         
        
       
      
      ]
     
    
   
   ;
  
 

based on the principle of equal MMF before and after the fault, fault-tolerant currents in case of open-circuit faults of two adjacent phases and two non-adjacent phases are calculated, respectively, wherein the five-phase permanent magnet fault-tolerant motor has no third harmonic current in case two phases are open-circuited, so the third harmonic current is ignored; and in case two non-adjacent phases (A, C) are open-circuited, the fault-tolerant currents are as follows:, {
  
   
    
     
      
       i
       
        B
        ⁢
        2
       
      
      =
      
       
        
         1
         .
         3
        
        ⁢
        8
        ⁢
        2
        ⁢
        
         i
         
          d
          ⁢
          1
         
         *
        
        ⁢
          
        cos
        ⁢
          
        
         (
         
          θ
          -
          γ
         
         )
        
       
       +
       
        
         1
         .
         3
        
        ⁢
        8
        ⁢
        2
        ⁢
        
         i
         
          q
          ⁢
          1
         
         *
        
        ⁢
          
        sin
        ⁢
          
        
         (
         
          θ
          -
          γ
         
         )
        
       
      
     
    
   
   
    
     
      
       i
       
        D
        ⁢
        2
       
      
      =
      
       
        
         -
         
          2
          .
          2
         
        
        ⁢
        3
        ⁢
        6
        ⁢
        
         i
         
          d
          ⁢
          1
         
         *
        
        ⁢
          
        cos
        ⁢
          
        θ
       
       -
       
        
         2
         .
         2
        
        ⁢
        3
        ⁢
        6
        ⁢
        
         i
         
          q
          ⁢
          1
         
         *
        
        ⁢
          
        sin
        ⁢
          
        θ
       
      
     
    
   
   
    
     
      
       i
       
        E
        ⁢
        2
       
      
      =
      
       
        
         2
         .
         2
        
        ⁢
        3
        ⁢
        6
        ⁢
        
         i
         
          d
          ⁢
          1
         
         *
        
        ⁢
          
        cos
        ⁢
          
        
         (
         
          θ
          +
          
           
            0
            .
            5
           
           ⁢
           γ
          
         
         )
        
       
       +
       
        
         2
         .
         2
        
        ⁢
        3
        ⁢
        6
        ⁢
        
         i
         
          q
          ⁢
          1
         
         *
        
        ⁢
          
        sin
        ⁢
          
        
         (
         
          θ
          +
          
           
            0
            .
            5
           
           ⁢
           γ
          
         
         )
        
       
      
     
    
   
  
 

wherein, iB2, iD2, and iE2 are currents of the phases B, D, and E when the phases A and C are open-circuited; and
in case two adjacent phases (A, B) are open-circuited, the fault-tolerant currents are as follows:, {
  
   
    
     
      
       i
       
        C
        ⁢
        3
       
      
      =
      
       
        
         2
         .
         2
        
        ⁢
        3
        ⁢
        6
        ⁢
        
         i
         
          q
          ⁢
          1
         
         *
        
        ⁢
          
        cos
        ⁢
          
        
         (
         
          θ
          -
          γ
         
         )
        
       
       +
       
        
         2
         .
         2
        
        ⁢
        3
        ⁢
        6
        ⁢
        
         i
         
          d
          ⁢
          1
         
         *
        
        ⁢
          
        sin
        ⁢
          
        
         (
         
          θ
          -
          γ
         
         )
        
       
      
     
    
   
   
    
     
      
       i
       
        D
        ⁢
        3
       
      
      =
      
       
        
         3
         .
         6
        
        ⁢
        18
        ⁢
        
         i
         
          q
          ⁢
          1
         
         *
        
        ⁢
        cos
        ⁢
          
        
         (
         
          θ
          +
          
           2
           ⁢
           γ
          
         
         )
        
       
       +
       
        
         3
         .
         6
        
        ⁢
        1
        ⁢
        8
        ⁢
        
         i
         
          d
          ⁢
          1
         
         *
        
        ⁢
          
        sin
        ⁢
          
        
         (
         
          θ
          +
          
           2
           ⁢
           γ
          
         
         )
        
       
      
     
    
   
   
    
     
      
       i
       
        E
        ⁢
        3
       
      
      =
      
       
        
         2
         .
         2
        
        ⁢
        3
        ⁢
        6
        ⁢
        
         i
         
          q
          ⁢
          1
         
         *
        
        ⁢
        cos
        ⁢
          
        θ
       
       +
       
        
         2
         .
         2
        
        ⁢
        3
        ⁢
        6
        ⁢
        
         i
         
          d
          ⁢
          1
         
         *
        
        ⁢
        sin
        ⁢
          
        θ
       
      
     
    
   
  
 

wherein, iC3, iD3, and iE3 are currents of the phases C, D, and E when the phases A and B are open-circuited;
when the five-phase permanent magnet fault-tolerant motor has the fault, adopting a corresponding fault-tolerant control strategy to ensure that the phase currents meet the requirements of the fault-tolerant currents, and to ensure the undisturbed operation of the motor under different faults.