1. Power Semiconductor Systems I
Author: Ales Havel
Phone: 5937
Office: EA333
Web:
Power Semiconductor Systems I

2. Presentation contents
Main types of converters
AC-DC converters
DC-DC converters
1-quadrant choppers
Buck converter
Boost converter
Buck-Boost converter
Resistance converters
2-quadrant choppers
4-quadrant choppers
DC-AC converters
AC-AC converters

3. Power converters
A power semiconductor converter is an electrical device for converting electrical energy.

4. 1-Quadrant DC/DC converters
Buck converter (step down)
Load voltage for continuous load current case:
Load voltage for discontinuous load current case:
Discontinuous load current
Load current (transistor time)
Continuous load current
Load current (diode time)

5. 1-Quadrant DC/DC converters
Example 1:
The Buck converter is working with the R + L + Ui type of the load. The duty cycle of the converter (z) is 15% and the switching frequency (f) is 200Hz. Evaluate the UAV load voltage for these cases: (U = 100V, Ui = 20V)
Continuous load current
Bypass diode conducting time is T/3.
Solution: 1) 2)

6. 1-Quadrant DC/DC converters
Boost converter (step up)
Load voltage for continuous load current case:
Load voltage for discontinuous load current case:
Discontinuous load current
Max. load current (transistor time)
Continuous load current
Min. load current (diode time)

7. 1-Quadrant DC/DC converters
Example 1:
The Boost converter is working with the R + L + Ui type of the load. The transistor conducting time T1 = 1ms, the bypass diode conducting time is 1ms. The switching frequency (f) is 400Hz. Evaluate the UAV load voltage, if U = 100V and Ui = 30V.
Solution:

8. 1-Quadrant DC/DC converters
Resistance converter without capacitor
Resistance converter with capacitor
Regulation range of equivalent resistance:
Regulation range of equivalent resistance:

9. 2-Quadrant DC/DC converters
2-Quadrant DC/DC converter with current reversion:

10. 2-Quadrant DC/DC converters
2-Quadrant DC/DC converter with voltage reversion:

11. 4-Quadrant DC/DC converters
2 ways of control:
Bipolar

12. 4-Quadrant DC/DC converters
2 ways of control:
Unipolar

13. Thank You for your attention