1. 1800 conduction mode of
3 phase inverter
Manikandan.S
M.Tech Power System

4. 180° Conduction
• Three transistors ON at a time

5. Summary Table

6. Waveforms for 180° Conduction

7. Phase Voltages for 180° Conduction

8. Waveforms for 180° Conduction

9. Summary Table

10. Mode 1 Operation

11. Mode 1 Operation
π
0 ≤ ωt ≤
3
R 3R
Req = R + =
2
2
Vs
2Vs
i1 =
=
Req
3R
Q1, Q5, Q6 conduct
i1 R Vs
van = vcn =
=
2
3
−2Vs
vbn = −i1 R =
3

12. Summary Table

13. Mode 2 Operation

14. Mode 2 Operation
π
2π
≤ ωt ≤
3
3
R 3R
Req = R + =
2
2
Vs
2Vs
i2 =
=
Req
3R
Q1, Q2, Q6 conduct
2Vs
van = i2 R =
3
−i2 R −Vs
vbn = vcn =
=
2
3

15. Summary Table

16. Mode 3 Operation

17. Mode 3 Operation
2π
≤ ωt ≤ π
3
R 3R
Req = R + =
2
2
Vs
2Vs
i3 =
=
Req
3R
Q1, Q2, Q3 conduct
i3
van = vbn =
2
−2Vs
vcn = i3 R =
3

18. Phase Voltages for 180° Conduction