Simulation and Analysis of Zero Voltage Switching PWM Full Bridge Converter
ABSTRACT:
In the conventional zero
voltage switching full bridge converter the introduction of a resonant inductance
and clamping diodes are introduced the voltage oscillation across the rectifier
diodes is eliminated and the load range for zero-voltage switching (ZVS)
achievement increases. When the clamping diode is conducting, the resonant inductance
is shorted and its current keeps constant. So the clamping diode is hard
turned-off, leading to reverse recovery loss if the output filter inductance is
relatively larger. By introducing a reset winding in series with the resonant
inductance to make the clamping diode current decay rapidly when it conducts
this paper improves the full-bridge converter. The conduction losses are
reduced by the use of reset winding. Also the clamping diodes naturally
turn-off and avoids the reverse recovery. The proposed converter has been
simulated for two different configurations and results have been compared. A 1
kW prototype converter is built to verify the operation principle and the
experimental results are also demonstrated.
KEYWORDS:
1. Clamping
diodes
2. Full
bridge converter
3. Reset
winding
4. Zero-voltage-switching
(ZVS).
SOFTWARE: MATLAB/SIMULINK
CIRCUIT DIAGRAM:
Fig: 1. Tr-Lag type ZVS full bridge PWM full
bridge converter
Fig:2 Tr-Lead type ZVS
full bridge PWM full bridge converter
EXPECTED SIMULATION RESULTS:
Fig:9. Voltage Across Switch Q1 (Tr-Lead)
Fig:10. Current Through Lr (Tr-Lead)
Fig;11:Inverter output Voltage (Tr-Lead)
Fig:12. Rectifier Output Voltage (Tr-Lead)
CONCLUSION:
A
ZVS PWM full-bridge converter is proposed in this paper, it employs an
additional reset winding to make the clamping diode current decay rapidly when
the clamping diode conducts, thus the conduction losses of the clamping diodes.
The reset winding removes the need of auxiliary switches and the resonant
inductance is reduced. The use of reset winding removes the need of hard
switching for clamping diodes so there will not be any power loss due to
switching of clamping diodes and the conversion efficiency will increased. In
the meanwhile, the clamping diodes can be turned off naturally without reverse recovery
over the whole input voltage range, and the output filter inductance can be
designed to be large to obtain small current ripple, leading to reduced filter
capacitance. Compared with the traditional full bridge converter, the proposed
circuit provides another simple and effective approach to avoid the reverse
recovery of the clamping diodes. The structure and operation of the proposed
ZVS PWM full-bridge converter with reset winding topology are described and two
configurations have been studied i.e. Transformer leading and
Transformer-Lagging connections. We have studied the performance of both the configuration.
If we compare the rectifier output in both the case we find that Tr-Lag
connection produces less ripples. Transformer lagging configuration is
advisable for more accurate results.
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