DC/DC converter
AssigneeSMA Solar Technology AG
InventorsRegine Mallwitz, Peter Zacharias, Bernd Engel
Life of this patent
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Abstract
The object of the invention is a high-efficiency DC/DC converter, in particular for photovoltaic plants, incorporating a transformerless DC/DC converter operated in the resonant mode of operation for converting a unipolar direct input voltage with an associated positive pole (+) and with a negative pole (−). There is imposed a resonance circuit incorporating at least one resonance inductance and at least one resonance capacitance, each resonance capacitance being connected to a respective one of the rectifier circuit arrangements in such a manner that the bipolar direct output voltage is provided, a voltage boosting circuit arrangement being connected to each resonance capacitance and to the rectifier circuit arrangement.
Claims35
A transformerless DC/DC converter operated in a resonant mode of operation for converting a unipolar direct input voltage with an associated positive pole and a negative pole into a bipolar direct output voltage with an associated positive pole, a grounding pole and a negative pole, the DC/DC converter comprising:
- a resonance circuit incorporating at least one resonance inductance and at least one resonance capacitance;
- a respective rectifier circuit arrangement coupled to each resonance capacitance in such a way that the bipolar direct output voltage is produced;
- and
- a voltage boosting circuit arrangement connected to each resonance capacitance and to the rectifier circuit arrangement.
A transformerless power converter comprising:
- a plurality of switches coupled to a plurality of DC input terminals;
- a resonant circuit coupled to the plurality of switches, the resonant circuit comprising an inductor and a series capacitor;
- a rectifying bridge coupled to the series capacitor, the rectifying bridge configured to output a DC voltage at a plurality of output terminals;
- and
- a voltage boosting circuit coupled between the resonant circuit and the rectifying bridge, the voltage boosting circuit comprising at least one switch configured to be closed during a time period in which an absolute value of the inductor is increasing, and be open when energy is transferred from the resonant circuit to the rectifying bridge.
A method of operating a transformerless power converter comprising a plurality of switches coupled to a plurality of DC input terminals, a resonant circuit coupled to the plurality of switches, the resonant circuit comprising an inductor and a series capacitor, at least one further switch coupled to the resonant circuit, and a rectifying bridge coupled to the at least one further switch, the rectifying bridge configured to output a DC voltage at a plurality of output terminals, the method comprising:
- alternatively coupling the inductor to each of the plurality of DC input terminal for a first pulse duration;
- and
- applying a low impedance to the resonant circuit during a first portion of the first pulse duration, the first portion of the first pulse duration being shorter than the first pulse duration.
A transformerless resonant DC/DC converter for converting a DC input voltage at DC input terminals into a bipolar DC output voltage at a positive, a neutral and a negative DC output terminal, the converter comprising:
- a bridge circuit coupled to the DC input terminals;
- and
- a rectifier comprising
- a first rectifier bridge coupled between the positive and the neutral DC output terminals, and
- a second rectifier bridge coupled between the negative and the neutral DC output terminals, wherein the bridge circuit is coupled to the first rectifier bridge by a first series connection of a first inductor and a first capacitor, and the bridge circuit is coupled to the second rectifier bridge by a second series connection of a second inductor and a second capacitor.
A transformerless resonant DC/DC converter for converting a DC input voltage at DC input terminals into a bipolar DC output voltage at a positive, a neutral and a negative DC output terminal, the converter comprising:
- a bridge circuit coupled to the DC input terminals;
- a rectifier bridge coupled between the positive and the negative DC output terminal, wherein the bridge circuit is coupled to the rectifier bridge at a coupling point by a series connection of an inductor and a capacitor;
- and
- a boost circuit arrangement providing a switchable connection between the coupling point and the neutral DC output terminal, wherein the neutral DC output terminal is connected to one of the DC input terminals.
Dependencies are inferred from the claim text.