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

Claim 6:
7. The unified open-circuit fault-tolerant control method according to claim 6, wherein step 8) is implemented as follows, wherein
the back-EMF of the five-phase permanent magnet fault-tolerant motor remains unchanged under an open-circuit fault and under normal operation; because the amplitude of the permanent magnet flux linkage of the five-phase permanent magnet fault-tolerant motor changes little and the back-EMF has a small harmonic content, the back-EMF of the five phases is expressed as follows:, [
   
    
     
      
       e
       A
      
     
    
    
     
      
       e
       B
      
     
    
    
     
      
       e
       C
      
     
    
    
     
      
       e
       D
      
     
    
    
     
      
       e
       E
      
     
    
   
   ]
  
  =
  
   -
   
    
     ωψ
     f
    
    [
    
     
      
       
        sin
        ⁢
          
        θ
       
      
     
     
      
       
        sin
        ⁢
          
        
         (
         
          θ
          -
          γ
         
         )
        
       
      
     
     
      
       
        sin
        ⁢
          
        
         (
         
          θ
          -
          
           2
           ⁢
           γ
          
         
         )
        
       
      
     
     
      
       
        sin
        ⁢
          
        
         (
         
          θ
          -
          
           3
           ⁢
           γ
          
         
         )
        
       
      
     
     
      
       
        sin
        ⁢
          
        
         (
         
          θ
          -
          
           4
           ⁢
           γ
          
         
         )
        
       
      
     
    
    ]
   
  
 

wherein, ψf is the amplitude of the permanent magnet flux linkage, and ω is the electrical angular velocity;
substituting the back-EMF into the phase voltage expression of the five-phase permanent magnet fault-tolerant motor leads to corresponding predetermined values of the fault-tolerant voltages under different fault modes; and when a winding of the phase A is faulty, the predetermined fault-tolerant phase voltages are expressed as follows:

 
  
   [
   
    
     
      
       u
       B
       *
      
     
    
    
     
      
       u
       C
       *
      
     
    
    
     
      
       u
       D
       *
      
     
    
    
     
      
       u
       E
       *
      
     
    
   
   ]
  
  =
  
   
    
     T
     p
    
    [
    
     
      
       
        u
        
         ed
         ⁢
         1
        
        *
       
      
     
     
      
       
        u
        
         eq
         ⁢
         1
        
        *
       
      
     
     
      
       
        u
        
         ed
         ⁢
         3
        
        *
       
      
     
     
      
       
        u
        
         eq
         ⁢
         3
        
        *
       
      
     
    
    ]
   
   +
   
    [
    
     
      
       
        e
        B
       
      
     
     
      
       
        e
        C
       
      
     
     
      
       
        e
        D
       
      
     
     
      
       
        e
        E
       
      
     
    
    ]
   
  
 

uA*=eA;

when windings of the phases A and C are faulty, the predetermined fault-tolerant phase voltages are expressed as follows:, {
  
   
    
     
      
       u
       A
       *
      
      =
      
       e
       A
      
     
    
   
   
    
     
      
       u
       B
       *
      
      =
      
       
        1.382
        
         u
         
          eq
          ⁢
          1
         
         *
        
        ⁢
          
        cos
        ⁢
          
        
         (
         
          θ
          -
          γ
         
         )
        
       
       +
       
        1
        .382
        
         u
         
          ed
          ⁢
          1
         
         *
        
        ⁢
          
        sin
        ⁢
          
        
         (
         
          θ
          -
          γ
         
         )
        
       
       +
       
        e
        B
       
      
     
    
   
   
    
     
      
       u
       C
       *
      
      =
      
       e
       C
      
     
    
   
   
    
     
      
       u
       D
       *
      
      =
      
       
        
         -
         2.236
        
        ⁢
        
         u
         
          eq
          ⁢
          1
         
         *
        
        ⁢
          
        cos
        ⁢
          
        θ
       
       -
       
        2
        .236
        
         u
         
          ed
          ⁢
          1
           
         
         *
        
        ⁢
          
        sin
        ⁢
          
        θ
       
       +
       
        e
        D
       
      
     
    
   
   
    
     
      
       u
       E
       *
      
      =
      
       
        2.236
        
         u
         
          eq
          ⁢
          1
         
         *
        
        ⁢
          
        cos
        ⁢
          
        
         (
         
          θ
          +
          
           
            0
            .
            5
           
           ⁢
           γ
          
         
         )
        
       
       +
       
        2
        .236
        
         u
         
          ed
          ⁢
          1
         
         *
        
        ⁢
          
        sin
        ⁢
          
        
         (
         
          θ
          +
          
           
            0
            .
            5
           
           ⁢
           γ
          
         
         )
        
       
       +
       
        e
        E
       
      
     
    
   
  
 

when windings of the phases A and B are faulty, the predetermined fault-tolerant phase voltages are expressed as follows:, {
  
   
    
     
      
       u
       A
       *
      
      =
      
       e
       A
      
     
    
   
   
    
     
      
       u
       B
       *
      
      =
      
       e
       B
      
     
    
   
   
    
     
      
       u
       C
       *
      
      =
      
       
        2.236
        
         u
         
          eq
          ⁢
          1
         
         *
        
        ⁢
          
        cos
        ⁢
          
        
         (
         
          θ
          -
          γ
         
         )
        
       
       +
       
        2
        .236
        
         u
         
          ed
          ⁢
          1
         
         *
        
        ⁢
          
        sin
        ⁢
          
        
         (
         
          θ
          -
          γ
         
         )
        
       
       +
       
        e
        C
       
      
     
    
   
   
    
     
      
       u
       D
       *
      
      =
      
       
        3.618
        
         u
         
          eq
          ⁢
          1
            
         
         *
        
        ⁢
        cos
        ⁢
          
        
         (
         
          θ
          +
          
           2
           ⁢
           γ
          
         
         )
        
       
       +
       
        3
        .618
        
         u
         
          ed
          ⁢
          1
         
         *
        
        ⁢
          
        sin
        ⁢
          
        
         (
         
          θ
          +
          
           2
           ⁢
           γ
          
         
         )
        
       
       +
       
        e
        D
       
      
     
    
   
   
    
     
      
       u
       E
       *
      
      =
      
       
        2.236
        
         u
         
          eq
          ⁢
          1
         
         *
        
        ⁢
          
        cos
        ⁢
          
        θ
       
       +
       
        2
        .236
        
         u
         
          ed
          ⁢
          1
         
         *
        
        ⁢
          
        sin
        ⁢
          
        θ
       
       +
       
        e
        E
       
      
     
    
   
  
 

when the direct-axis and quadrature-axis voltages ud* and uq* of the five-phase permanent magnet fault-tolerant motor drive system are known, based on the expression of the predetermined fault-tolerant phase voltages, the fault-tolerant operation of the system is achieved in case of an open-circuit fault of a motor winding.