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Power Semiconductor Systems I. Author: Ales Havel E-mail: ales.havel@vsb.cz Phone number: 4287 Headquarters: E227 Web page: http://homen.vsb.cz/~ hav278 /. Presentation contents. Main types of converters AC-DC converters DC-DC converters 1-quadrant choppers Buck converter
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Power Semiconductor Systems I Author: Ales Havel E-mail:ales.havel@vsb.cz Phone number: 4287 Headquarters: E227 Web page: http://homen.vsb.cz/~hav278/
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
Power converters • A power semiconductor converter is an electrical device for converting electrical energy.
1-Quadrant choppers Buck converter (step down chopper) 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:
1-Quadrant choppers 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)
1-Quadrant choppers Boost converter (step up chopper) 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:
1-Quadrant choppers 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:
1-Quadrant choppers Resistance converter without capacitor Resistance converter with capacitor Regulation range of equivalent resistance: Regulation range of equivalent resistance:
2-Quadrant choppers 2-Quadrant DC/DC converter with current reversion:
2-Quadrant choppers 2-Quadrant DC/DC converter with voltage reversion:
4-Quadrant chopper 2 ways of control: • Bipolar
4-Quadrant chopper 2 ways of control: • Unipolar