Power conversion with added pseudo-phase
Methods and systems for power conversion. An energy storage capacitor is contained within an H-bridge subcircuit which allows the capacitor to be connected to the link inductor of a Universal Power Converter with reversible polarity. This provides a “pseudo-phase” drive capability which expands the capabilities of the converter to compensate for zero-crossings in a single-phase power supply.
1. A method for operating a Buck-Boost Converter, comprising the actions of:
(a) operating a first bridge switch array, comprising bidirectional switching devices, to operatively connect at least one terminal of a reactance to a power input, with polarity which reverses at different times;
(b) operating a second bridge switch array, comprising bidirectional switching devices, to operatively connect at least one terminal of said reactance to a power output, with polarity which reverses at different times;
(c) operating an H-bridge switch subarray to operatively connect an energy storage capacitor to said reactance at various times, with polarity which reverses at various times, to provide net energy transfer into and out of said energy storage capacitor; and
wherein said actions (a) and (b) are not performed simultaneously.
2. The method of claim 1 , wherein said bridge arrays are symmetrically connected to said energy-transfer reactance.
3. The method of claim 1 , wherein said energy-transfer reactance comprises a transformer.
4. A method for operating a Buck-Boost Converter, comprising the actions of:
(d) operating a first bridge switch array, comprising bidirectional switching devices, to operatively connect at least one terminal of a reactance to a power input, with polarity which reverses at different times;
(e) operating a second bridge switch array, comprising bidirectional switching devices, to operatively connect at least one terminal of said reactance to a power output, with polarity which reverses at different times;
(f) operating an H-bridge switch subarray to operatively connect an energy storage capacitor to said reactance at various times, with polarity which reverses at various times, to provide net energy transfer into and out of said energy storage capacitor; and
wherein said actions (a) and (b) are not performed simultaneously, wherein said energy-transfer reactance comprises a parallel combination of an inductor with a capacitor.
5. A method for operating a Buck-Boost Converter, comprising the actions of:
(g) operating a first bridge switch array, comprising bidirectional switching devices, to operatively connect at least one terminal of a reactance to a power input, with polarity which reverses at different times;
(h) operating a second bridge switch array, comprising bidirectional switching devices, to operatively connect at least one terminal of said reactance to a power output, with polarity which reverses at different times;
(i) operating an H-bridge switch subarray to operatively connect an energy storage capacitor to said reactance at various times, with polarity which reverses at various times, to provide net energy transfer into and out of said energy storage capacitor; and
wherein said actions (a) and (b) are not performed simultaneously, wherein said reactance is driven at a base frequency which is less than half its resonant frequency.