Modified high-efficiency phase shift modulation method
AssigneeChang Gung University
InventorYi-Hwa Liu
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Abstract
Disclosed is a high-efficiency phase shift modulation method suitable for use in a traditional DC/AC single-phase full-bridge inverter. In this method, phase-shifted signal timing is used to modulate a duty cycle so that a power transistor is operated in a zero voltage switching state. As such, noises and switching loss of a switching device when turned on or off, may be reduced and thus efficiency of the inverter may be promoted. With this high-efficiency phase shift modulation method, at least the following advantages may be achieved: lower switching stresses, lower switching losses and thus increased conversion efficiency, lower electromagnetic interferences (EMIs) and no additional circuit required and thus easier realization of a controller for the inverter.
Claims4
A modified phase-shift modulation technology applied in a single-phase DC-AC inverter, being capable of soft switching the same, outputting an AC voltage and comprising a controller, the controller comprising:
- a basic square wave generation circuit configured to generate a first square wave having a duty cycle of 50%;
- a phase shift circuit configured to generate a square wave having a second duty cycle proportional to a desired output and a center line symmetrical with the square wave aforementioned;
- a dead time generation circuit adapted to add a dead time into the first and second square waves;
- and
- a comparator and a counter adapted to provide timings for the basic square wave generation circuit, phase shift circuit dead time generation circuit.
Dependencies are inferred from the claim text.