Soft-switching, high performance single-phase AC-DC converter
AssigneeArizona Board of Regents on behalf of Arizona State University
InventorRajapandian Ayyanar
Life of this patent
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Abstract
A soft-switching, high-performance single-phase alternating current (AC)-direct current (DC) converter is provided. The AC-DC converter described herein provides a new circuit topology for single-stage, single-phase or multi-phase AC-DC power conversion with power factor correction (PFC) and galvanic isolation using a high-frequency isolation transformer. The AC-DC converter improves power conversion efficiency and power density—two of the most important metrics for a power converter. It achieves soft switching for high frequency switches in the circuit, leading to higher efficiency and lower electromagnetic interference (EMI).
Claims20
An alternating current (AC)-direct current (DC) converter, comprising:
- an AC input/output (I/O) comprising a first AC I/O node and a second AC I/O node;
- a DC I/O comprising a first DC I/O node and a second DC I/O node;
- an isolation transformer, comprising:
- a first coil comprising a first terminal coupled to the first AC I/O node and a second terminal;
- and
- a second coil magnetically coupled to the first coil and comprising a third terminal coupled to the first DC I/O node and a fourth terminal coupled to the second DC I/O node;
- a first switch coupled between the first AC I/O node and a common top node;
- a second switch coupled between the first AC I/O node and a common bottom node;
- a first capacitor coupled across the first switch and the second switch;
- a third switch connected between the common top node and the second AC I/O node;
- and
- a fourth switch connected between the second AC I/O node and the second terminal of the first coil of the isolation transformer;
- wherein:
- the third switch and the fourth switch are configured to switch at a line frequency;
- and
- the first switch and the second switch are configured to switch at a higher switching frequency than the line frequency.
A circuit, comprising:
- an isolation transformer, comprising:
- a primary coil;
- and
- a secondary coil;
- a direct current (DC) circuit coupled to the isolation transformer;
- and
- an alternating current (AC) circuit coupled to the isolation transformer and galvanically isolated from the DC circuit, the AC circuit comprising:
- a bridgeless single-stage power factor correction circuit isolated from the DC circuit;
- a first zero-voltage switch (ZVS) connected in shunt to a first node between an AC source or load and a first terminal of the primary coil;
- and
- a second ZVS connected in shunt to the first node.
An alternating current (AC)-direct current (DC) converter, comprising:
- an AC input/output (I/O) comprising a first AC I/O node and a second AC I/O node;
- a DC I/O comprising a first DC I/O node and a second DC I/O node;
- an isolation transformer, comprising:
- a first coil comprising a first terminal coupled to the first AC I/O node and a second terminal;
- and
- a second coil magnetically coupled to the first coil and comprising a third terminal coupled to the first DC I/O node and a fourth terminal coupled to the second DC I/O node;
- an inductor connected between the first AC I/O node and an intermediate high-frequency node;
- a first switch coupled between the intermediate high-frequency node and a common top node;
- a second switch coupled between the intermediate high-frequency node and a common bottom node;
- a first capacitor coupled across the first switch and the second switch;
- a third switch connected between the common top node and the second AC I/O node;
- and
- a fourth switch connected between the second AC I/O node and the second terminal of the first coil of the isolation transformer.
Dependencies are inferred from the claim text.