US-12620900-B1 - Power converter with integrated secondary multi-purpose network

US12620900B1US 12620900 B1US12620900 B1US 12620900B1US-12620900-B1

Abstract

A power converter includes a DC-DC converter configured to operate in at least a boost mode so as to step up a first voltage input at a low side terminal to a second voltage output at a high side terminal. A first transistor is provided and has a body diode oriented in a first direction. A second transistor having a body diode oriented in an opposite second direction is also provided. The first and second transistors are in series with one another and are electrically connected between the low side terminal and the DC-DC converter. A third transistor is connected between a common terminal and the DC-DC converter. The first, second, and third transistors are controllable as switches to at least temporarily operate the power converter to step down the first voltage input at the low side terminal to a third voltage output at the high side terminal.

Inventors

Pallav Tiwari
Aleksandar Lazarov
Harm Hessels

Assignees

NAVICO GROUP AMERICAS LLC

Dates

Publication Date: 20260505
Application Date: 20240419

Claims (10)

1 . A power converter comprising: a low side terminal; a high side terminal; a common terminal; a DC-DC converter electrically connected between the high side terminal and the low side terminal, the DC-DC converter being configured to operate in at least a boost mode so as to step up a first voltage input at the low side terminal to a second voltage output at the high side terminal; a first transistor having a body diode oriented in a first direction; a second transistor having a body diode oriented in an opposite second direction, the first and second transistors being in series with one another and electrically connected between the low side terminal and the DC-DC converter; and a third transistor connected between the common terminal and the DC-DC converter, wherein the first, second, and third transistors are controllable as switches to at least temporarily operate the power converter to step down the first voltage input at the low side terminal to a third voltage output at the high side terminal.
2 . The power converter of claim 1 , further comprising a gate driver controlling operation of the first, second, and third transistors as switches; wherein the gate driver is configured to turn the first and second transistors on and simultaneously to turn the third transistor off; and wherein the gate driver is configured to turn the third transistor on and simultaneously to turn the first and second transistors off.
3 . The power converter of claim 2 , further comprising a controller in signal communication with the gate driver; wherein the controller is configured to compare a measured voltage at the high side terminal to a measured voltage at the low side terminal; and wherein in response to determining that the measured voltage at the high side terminal is less than the measured voltage at the low side terminal, the controller controls the gate driver to operate the first, second, and third transistors as switches to step down the first voltage input at the low side terminal to the third voltage output at the high side terminal; and wherein in response to determining that the measured voltage at the high side terminal is greater than the measured voltage at the low side terminal, the controller controls the DC-DC converter to operate in the boost mode.
4 . The power converter of claim 1 , further comprising: a fourth transistor having a body diode oriented in the first direction; and a fifth transistor having a body diode oriented in the second direction; wherein the fourth and fifth transistors are in series with one another and in parallel with the first and second transistors, and are electrically connected between the low side terminal and the DC-DC converter; and wherein the first, second, third, fourth, and fifth transistors are controllable as switches to at least temporarily operate the power converter to step down the first voltage input at the low side terminal to the third voltage output at the high side terminal.
5 . The power converter of claim 1 , wherein the first and second transistors are oriented such that their respective sources face one another.
6 . The power converter of claim 1 , wherein the third transistor is connected between the common terminal and the DC-DC converter and between the first transistor and the common terminal.
7 . The power converter of claim 1 , wherein the DC-DC converter is also configured to operate in a buck mode so as to step down the second voltage input at the high side terminal to the first voltage output at the low side terminal.
8 . The power converter of claim 1 , wherein the DC-DC converter has an interleaved topology.
9 . The power converter of claim 1 , wherein the DC-DC converter is a non-isolated converter.
10 . The power converter of claim 1 , wherein at least one of the first, second, and third transistors is a MOSFET.

Description

FIELD The present disclosure relates to power converters including DC-DC converters configured to operate in at least boost mode. BACKGROUND Bidirectional (buck-boost) DC-DC converters are known. Such DC-DC converters operate in both a buck mode to step down voltage and a boost mode to step up voltage and include diodes, transistors (e.g., MOSFETs), and a capacitor and/or and an inductor for providing such functionality. SUMMARY This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. One example of the present disclosure contemplates a power converter comprising a low side terminal, a high side terminal, and a common terminal. A DC-DC converter is electrically connected between the high side terminal and the low side terminal. The DC-DC converter is configured to operate in at least a boost mode so as to step up a first voltage input at the low side terminal to a second voltage output at the high side terminal. A first transistor is provided and has a body diode oriented in a first direction. A second transistor having a body diode oriented in an opposite second direction is also provided. The first and second transistors are in series with one another and are electrically connected between the low side terminal and the DC-DC converter. A third transistor is connected between the common terminal and the DC-DC converter. The first, second, and third transistors are controllable as switches to at least temporarily operate the power converter to step down the first voltage input at the low side terminal to a third voltage output at the high side terminal. According to one aspect, the power converter further comprises a gate driver controlling operation of the first, second, and third transistors as switches. The gate driver is configured to turn the first and second transistors on and simultaneously to turn the third transistor off. The gate driver is also configured to turn the third transistor on and simultaneously to turn the first and second transistors off. According to one aspect, the power converter further comprises a controller in signal communication with the gate driver. The controller is configured to compare a measured voltage at the high side terminal to a measured voltage at the low side terminal. In response to determining that the measured voltage at the high side terminal is less than the measured voltage at the low side terminal, the controller controls the gate driver to operate the first, second, and third transistors as switches to step down the first voltage input at the low side terminal to the third voltage output at the high side terminal. In response to determining that the measured voltage at the high side terminal is greater than the measured voltage at the low side terminal, the controller controls the DC-DC converter to operate in the boost mode. According to one aspect, the power converter further comprises a fourth transistor having a body diode oriented in the first direction and a fifth transistor having a body diode oriented in the second direction. The fourth and fifth transistors are in series with one another and in parallel with the first and second transistors, and are electrically connected between the low side terminal and the DC-DC converter. The first, second, third, fourth, and fifth transistors are controllable as switches to at least temporarily operate the power converter to step down the first voltage input at the low side terminal to the third voltage output at the high side terminal. According to one aspect, the first and second transistors are oriented such that their respective sources face one another. According to one aspect, the third transistor is connected between the common terminal and the DC-DC converter and between the first transistor and the common terminal. According to one aspect, the DC-DC converter is also configured to operate in a buck mode so as to step down the second voltage input at the high side terminal to the first voltage output at the low side terminal. According to one aspect, the DC-DC converter has an interleaved topology. According to one aspect, the DC-DC converter is a non-isolated converter. According to one aspect, at least one of the first, second, and third transistors is a MOSFET. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure is described with reference to the following Figures. The same numbers are used throughout the Figures to reference like features and like components. FIG. 1 illustrates a power converter with a prior art bidirectional interleaved DC-DC converter. FIG. 2 illustrates the DC-DC converter of FIG. 1 with an additional switch added to prevent uncontrolled current flow through the DC-DC converter when operating in boost mode. FIG. 3 illustr