Patent ID: 11894776
Assignee: UTAH STATE UNIVERSITY
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 17:
18. A bidirectional power converter comprising:
a primary H-bridge comprising a first semi-conductor switch, a second semi-conductor switch, a third semi-conductor switch, and a fourth semi-conductor switch, wherein the first semi-conductor switch and the second semi-conductor switch are in leg A with terminal A between the first semi-conductor switch and the second semi-conductor switch in leg A and the third semi-conductor switch and the fourth semi-conductor switch are in leg B with terminal B between the third semi-conductor switch and the fourth semi-conductor switch in leg B, said terminal A and said terminal B forming an output of the primary H-bridge;
an LCL-Transformer section comprising a first inductor Lr with a first end connected to terminal A, a capacitor Cr connected between a second end of the first inductor Lr and said terminal B, and a second inductor Lg with a first end connected to the second end of the first inductor Lr;
a transformer with a primary side connected between a second end of the second inductor Lg and said terminal B, the transformer comprising a turns ratio n;
a secondary H-bridge comprising a fifth semi-conductor switch, a sixth semi-conductor switch, a seventh semi-conductor switch, and an eight semi-conductor switch with an input connected to a secondary side of the transformer, wherein the fifth and sixth semi-conductor switches are in leg D with terminal D between the fifth and sixth semi-conductor switches of leg D and the seventh and eighth semi-conductor switches are in leg E with terminal E between the seventh and eighth semi-conductor switches of leg E, terminal D and terminal E forming an output of the secondary H-bridge; and
an output capacitor Cf connected across said terminal D and said terminal E,
wherein the primary H-bridge is fed by a direct current (DC) constant current source, and wherein said terminals D and E are connected to a load and an output voltage across said terminals D and E is regulated to maintain a constant DC output voltage,
wherein:
the first, second, third and fourth semi-conductor switches of the primary H-bridge are operated with symmetrical phase shift modulation with leg A leading leg B by an angle conductor φAB;
the fifth, sixth, seventh, and eighth semi-conductor switches of the secondary H-bridge are operated with symmetrical phase shift modulation with leg D leading leg E by an angle φDE;
an angle between leg A and leg D is angle φAD; and
a power flow direction from the primary H-bridge to the secondary H-bridge is dependent on a phase angle φPS, which is:, φ
   
    P
    ⁢
    S
   
  
  =
  
   
    φ
    
     A
     ⁢
     D
    
   
   -
   
    
     φ
     
      A
      ⁢
      B
     
    
    2
   
   +
   
    
     
      φ
      
       D
       ⁢
       E
      
     
     2
    
    .