Special Issue Article
Non Isolated Single Phase AC-AC Converter Based on Adaptive Continuous Current Source Drive
|Ajith Ashokan1, Salice Peter2, Kiran Boby3
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Current source drivers (CSDs) have been reduce the switching loss and gate drive loss in megahertz (MHz) dc-dc converters, in which the duty cycle normally has a steady-state value. However, different from dc-dc converters, the duty cycle of the power factor correction (PFC) converters is modulated fast and has a wide operating range during a half-line period in ac –dc applications. An adaptive full-bridge CSD is used as a boost PFC converters. The CSD can build adaptive drive current inherently depending on the drain current of the main power MOSFET. Compared to the CSDs with the constant drive current, the advantage of the adaptive drive current is reduce the switching loss further when the MOSFET is with a higher switching current, while minimizing the drive circuit loss when the MOSFET is with a lower switching current. Therefore, the adaptive CSD is able to realize better design tradeoff between the switching losses and drive circuit loss so that the efficiency can be optimized in a wide operation range. Furthermore, no additional auxiliary circuit and control are needed to realize the adaptive current. A full bridge (FB) inverter at the back end of dc-dc converter completes the ac-ac conversion. This circuit enables to provide controlled and regulated ac output. The AC-AC converter is designed and simulated using MATLAB 2010 and waveforms are analysied. Simulation results demonstrate that the output voltage of the desired converter can be maintained at 349 V ac and Power factor can be improvedupto 0.909.