US-12620905-B2 - Methods and apparatus for controlling switching in power converters

US12620905B2US 12620905 B2US12620905 B2US 12620905B2US-12620905-B2

Abstract

A bridge configured for use with a power converter is provided herein. For example, a switch can include a Gallium-Nitride (GaN) High Electron Mobility Transistor and a Gate driver coupled to the Gallium-Nitride (GaN) High Electron Mobility Transistor and can be configured to provide a turn on signal to the Gallium-Nitride (GaN) High Electron Mobility Transistor at a first time so that the Gallium-Nitride (GaN) High Electron Mobility Transistor turns on at a second time that is different from the first time.

Inventors

Michael J. Harrison

Assignees

ENPHASE ENERGY, INC.

Dates

Publication Date: 20260505
Application Date: 20240319

Claims (15)

1 . A bridge configured for use with a power converter, comprising: a switch comprising a Gallium-Nitride (GaN) High Electron Mobility Transistor; and a Gate driver coupled to a gate of the Gallium-Nitride (GaN) High Electron Mobility Transistor and configured to provide a turn on signal to the Gallium-Nitride (GaN) High Electron Mobility Transistor at a first time when the Gallium-Nitride (GaN) High Electron Mobility Transistor is off so that the Gallium-Nitride (GaN) High Electron Mobility Transistor turns on at a second time that is different from the first time, wherein the first time is at approximately a mid-way point of a Zero Volt Switching (ZVS) commutation time that is when a rate of change of a blocking voltage (dV/dt) and a predetermined voltage (Vds) are reduced towards zero, and wherein the second time is at an end of the Zero Volt Switching (ZVS) commutation time.
2 . The bridge of claim 1 , wherein the Gallium-Nitride (GaN) High Electron Mobility Transistor is one of a Cascode GaN HEMT device, a gate injection transistor (GIT) GaN eHEMT device, or a Schottky Gate GaN eHEMT device.
3 . The bridge of claim 1 , wherein at the mid-way point of the Zero Volt Switching (ZVS) commutation time, the predetermined voltage (Vds) is about 400V across the Gallium-Nitride (GaN) High Electron Mobility Transistor and the rate of change of the blocking voltage (dV/dt) is about 5V/ns to about 50V/ns.
4 . The bridge of claim 1 , wherein the switch is one of a Uni-Directional switch, a Bi-Directional switch, or a Monolithic Bi-Directional Switch (MBDS).
5 . The bridge of claim 1 , wherein the switch comprises a pair of Gallium-Nitride (GaN) High Electron Mobility Transistors connected in series.
6 . A power conversion system, comprising: a converter; a DC component coupled to a DC side of the converter; a plurality of switches coupled to a primary winding of a transformer; and a bridge coupled to a secondary winding of the transformer and comprising: a switch comprising a Gallium-Nitride (GaN) High Electron Mobility Transistor; and a Gate driver coupled to a gate of the Gallium-Nitride (GaN) High Electron Mobility Transistor and configured to provide a turn on signal to the Gallium-Nitride (GaN) High Electron Mobility Transistor at a first time when the Gallium-Nitride (GaN) High Electron Mobility Transistor is off so that the Gallium-Nitride (GaN) High Electron Mobility Transistor turns on at a second time that is different from the first time, wherein the first time is at approximately a mid-way point of a Zero Volt Switching (ZVS) commutation time that is when a rate of change of a blocking voltage (dV/dt) and a predetermined voltage (Vds) are reduced towards zero, and wherein the second time is at an end of the Zero Volt Switching (ZVS) commutation time.
7 . The power conversion system of claim 6 , wherein the Gallium-Nitride (GaN) High Electron Mobility Transistor is one of a Cascode GaN HEMT device, a gate injection transistor (GIT) GaN eHEMT device, or a Schottky Gate GaN eHEMT device.
8 . The power conversion system of claim 6 , wherein at the mid-way point of the Zero Volt Switching (ZVS) commutation time, the predetermined voltage (Vds) is about 400V across the Gallium-Nitride (GaN) High Electron Mobility Transistor and the rate of change of the blocking voltage (dV/dt) is about 5V/ns to about 50V/ns.
9 . The power conversion system of claim 6 , wherein the switch is one of a Uni-Directional switch, a Bi-Directional switch, or a Monolithic Bi-Directional Switch (MBDS).
10 . The power conversion system of claim 6 , wherein the switch comprises a pair of Gallium-Nitride (GaN) High Electron Mobility Transistors connected in series.
11 . A method of controlling a bridge configured for use with a power converter, comprising: determining when a predetermined voltage (Vds) and a rate of change of a blocking voltage (dV/dt) is occurring at a Gallium-Nitride (GaN) High Electron Mobility Transistor; and providing a turn on signal at a first time to the Gallium-Nitride (GaN) High Electron Mobility Transistor when the Gallium-Nitride (GaN) High Electron Mobility Transistor is off so that the Gallium-Nitride (GaN) High Electron Mobility Transistor turns on at a second time that is different from the first time, wherein the first time is at approximately a mid-way point of a Zero Volt Switching (ZVS) commutation time that is when the rate of change of the blocking voltage (dV/dt) and the predetermined voltage (Vds) are reduced towards zero, and wherein the second time is at an end of the Zero Volt Switching (ZVS) commutation time.
12 . The method of claim 11 , wherein the Gallium-Nitride (GaN) High Electron Mobility Transistor is one of a Cascode GaN HEMT device, a gate injection transistor (GIT) GaN eHEMT device, or a Schottky Gate GaN eHEMT device.
13 . The method of claim 11 , wherein at the mid-way point of the Zero Volt Switching (ZVS) commutation time, the predetermined voltage (Vds) is about 400V across the Gallium-Nitride (GaN) High Electron Mobility Transistor and the rate of change of the blocking voltage (dV/dt) is about 5V/ns to about 50V/ns.
14 . The method of claim 11 , wherein the Gallium-Nitride (GaN) High Electron Mobility Transistor is a component of a switch that is one of a Uni-Directional switch, a Bi-Directional switch, or a Monolithic Bi-Directional Switch (MBDS).
15 . The method of claim 11 , wherein the Gallium-Nitride (GaN) High Electron Mobility Transistor is a component of a switch that comprises a pair of Gallium-Nitride (GaN) High Electron Mobility Transistors connected in series.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application claims the benefit of and priority to U.S. Provisional Application Ser. No. 63/459,048, filed on Apr. 13, 2023, the entire contents of which is incorporated herein by reference. BACKGROUND Field of the Disclosure Embodiments of the present disclosure relate generally to power conversion systems and, in particular, to methods and apparatus for controlling GaN HEMT devices using GaN HEMT Gate drive logic. Description of the Related Art Conventional power converters suitable for use with power conversion systems are known. The power converters can comprise one or more bridges that comprise one or more switches that are driven by a gate driver connected to one or more GaN HEMT (High Electron Mobility Transistor) devices that are connected to the one or more switches. The GaN HEMT devices are gaining popularity to replace conventional Si Super-Junction (SJ) MOSFET devices. For example, the GaN HEMT devices enable switched mode power converters to operate at switching frequencies that are much higher (e.g., 10×) than what is possible with conventional Si MOSFET devices, i.e., a typical switching frequency for Si MOSFET can be about 100 kHz and a GaN HEMT power transistors switching frequency can be about 1 MHz. The 10× increase in switching frequency can result in switching transition times reducing by an equivalent amount, i.e., a typical commutation time for a Si MOSFET device can be about 500 ns and an equivalent commutation time for the GaN HEMT device can be reduced to about 50 ns. Accordingly, the adoption of GaN HEMT devices requires a 10× increase in Gate drive timing accuracy. Retaining the Gate drive timing accuracy that was used with Si MOSFET devices, however, negates much of the performance advantage that is expected when changing from Si MOSFET devices to GaN HEMT devices. There are very few technology solutions available due to GaN technology being so new to the market, and the few solutions available tend to be expensive and somewhat lacking in performance. Thus, there is a need for improved methods and apparatus for controlling GaN HEMT devices using GaN HEMT Gate drive logic that achieves low-cost accurate timing. SUMMARY In accordance with at least some embodiments, a bridge configured for use with a power converter comprises a switch comprising a Gallium-Nitride (GaN) High Electron Mobility Transistor and a Gate driver coupled to a gate of the Gallium-Nitride (GaN) High Electron Mobility Transistor and configured to provide a turn on signal to one of the Gallium-Nitride (GaN) High Electron Mobility Transistor at a first time so that the Gallium-Nitride (GaN) High Electron Mobility Transistor turns on at a second time that is different from the first time. In accordance with at least some embodiments, a power conversion system comprises a converter, a DC component coupled to a DC side of the converter, a plurality of switches coupled to a primary winding of a transformer, and a bridge coupled to a secondary winding of the transformer and comprising a switch comprising a Gallium-Nitride (GaN) High Electron Mobility transistor and a Gate driver coupled to a gate of the Gallium-Nitride (GaN) High Electron Mobility Transistor and configured to provide a turn on signal to the Gallium-Nitride (GaN) High Electron Mobility Transistor at a first time so that the Gallium-Nitride (GaN) High Electron Mobility Transistor turns on at a second time that is different from the first time. In accordance with at least some embodiments, a method of controlling a bridge configured for use with a power converter comprises determining when a predetermined voltage (Vds) and a rate of change of a blocking voltage (dV/dt) is occurring at a Gallium-Nitride (GaN) High Electron Mobility Transistor and providing a turn on signal at a first time to the Gallium-Nitride (GaN) High Electron Mobility Transistor so that the Gallium-Nitride (GaN) High Electron Mobility Transistor turns on at a second time that is different from the first time. Various advantages, aspects, and novel features of the present disclosure may be appreciated from a review of the following detailed description of the present disclosure, along with the accompanying figures in which like reference numerals refer to like parts throughout. BRIEF DESCRIPTION OF THE DRAWINGS So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments. FIG. 1 is a schematic diagram of a power conversion system comprising a switched mode power converter, in accordan