Full Bridge Inverter Operation with Resistive Load

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Full Bridge Inverter Operation with Resistive Load

Q. Explain operation of single phase full bridge inverter with circuit diagram.

Q. Explain operation of single phase full bridge inverter with circuit diagram and Wave form.

Q. Single Phase Full Bridge Inverter Explained

Q. Single phase full bridge inverter output voltage equation

Operation of Full Bridge Inverter with Resistive Load

Mode l : (t0 to t1 ) :

  • With resistive load, SCRs 1 and 2 are turned on at instant t = t0 (See Figure C).
  • This will connect point A of the load to the positive end of the dc source voltage V and point B to the negative end of the source.
  • The load voltage VAB = – V as shown in Figure A. The load current flow from A to B and its amplitude is constant equal to IL = VAB / R where R is the load resistance.

Mode ll : (t1 to t2)

  • In order to reverse the load voltage polarities and load current directions, SCRs 1 and 2 are turned off and SCRS 3 and 4 are turned on at instant t = t1
  • This will make VAB = – V as shown in Figure C.

    Mode I (t0 to t1)
    Figure A
      Figure B
  • The load current now flows from B to A as shown in Figure B.
    Waveforms, for Bridge Inverter with Resistive Load
    Figure C
  • Note that the conducting SCRs are gated during their entire conduction period (see Figure C) At t = t2 SCRs 3 and 4 are turned off using some type of forced commutation and SCRs 1 and 2 are turned on.
  • The same power circuit configuration can be used to generate a square wave or a quasi square wave output voltage.
  • This is possible by turning off the conducting pair of SCRs first, provide some delay and then turn on the other pair of SCRs.
  • Due to the resistive nature of the load, the load does not store any energy, therefore there is no energy feedback from load to source through the diodes D1 and D4.

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