Type E Chopper (Power Electronic)

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Four Quadrant Chopper (Type E Chopper)

Questions

Q. Classify chopper based on output voltage and quadrants of operation. List any four applications of chopper.

Q. Classify choppers based quadrants of operation. Sketch only circuit diagram of each.

Q. Explain the operation of four quadrant chopper.

Q. Draw the circuit diagram of class E-chopper and explain its working.

Q. Explain the operation of four quadrant chopper with quadrant diagram.

Circuit diagram of type E-chopper 

  • We can visualize the type E chopper of Figure (A) as a combination of two type D choppers. The first type D chopper is made from the devices S1, S4, D3, D2 whereas the other type D chopper consists of the devices S2, S3, D1 and D4.
    Type E chopper Diagram
    Figure (A)
    4 quadrant operation of a type E chopper
    Figure (B)
  • The first type D chopper (S1, S4, D2 and D3) can operate in either quadrant Ist or IVth. Whereas the second type D chopper (S2, S3, D1 and D4) will operate it in the IInd or IIIrd quadrant.
  • The four quadrant operation of a type E chopper is summarized in Figure (B) The conducting devices , power / energy flow directions and equivalent dc motor load have also been shown.

Applications of type E chopper

  • The most important application of a type E chopper is the four quadrant reversible dc motor drive. This chopper enables us to reverse the direction of rotation and brake it electronically in either directions.

Merits and demerits of a four quadrant chopper (Type E chopper)

  1. Direction reversal of dc motor is possible. The motor can rotate in clockwise or anticlockwise direction.
  2. Regenerative braking in either directions is possible
  3. Fast dynamic response can be achieved.
  4. Close loop control of motors is possible.

The demerit of type E chopper is that it requires a very complex control circuit.

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