DC-to-DC converter for a welding device and method for operating a DC-to-DC converter of a welding device

Patent metadata

Field	Value
Publication number	US-12567809-B2
Application number	US-202117915723-A
Country	US
Kind code	B2
Filing date	Mar 30, 2021
Priority date	Mar 31, 2020
Publication date	Mar 3, 2026
Grant date	Mar 3, 2026

Abstract

To reduce energy losses for a welding device when on stand-by and to enable a clean and controlled start of the welding phase, a DC-to-DC converter of the welding device converts an input DC voltage present at an input connection to an output DC voltage present at an output connection. At least one switch element of a branch of the DC-to-DC converter is switched with a switching frequency, and a welding phase is provided for the welding device, during which the switching frequency corresponds to a normal switching frequency. A stand-by phase is provided for the welding device, during which the at least one switch element is switched with a switching frequency corresponding to a stand-by switching frequency which is lower than the normal switching frequency.

First claim

The invention claimed is:

1 . A method for operating a welding device, which includes a DC-to-DC converter that converts an input DC voltage present at an input connection into an output DC voltage present at an output connection, and a welding power unit having a power unit input at which the output DC voltage is present, the method comprising:
switching at least one switch element of a branch of the DC-to-DC converter with a switching frequency corresponding to a normal switching frequency or to a stand-by switching frequency, wherein, in a welding phase, the switching frequency corresponds to the normal switching frequency, and in a stand-by phase, in which no arc burns, the switching frequency corresponds to the stand-by switching frequency, which is lower than the normal switching frequency, during the welding phase, controlling, with the welding power unit, the output DC voltage present at the power unit input to a welding voltage present at a power unit output in the welding phase, effecting a switchover from the welding phase into the stand-by phase and/or from the stand-by phase into the welding phase by at least one of a transmitted control signal and/or a parameter determined in the welding device and maintaining the output DC voltage during the stand-by phase in order to provide the welding power unit with the output DC voltage required for an optimal start of the welding phase.

2 . The method according to claim 1 , wherein at least one further switch element of at least one further branch of the DC-to-DC converter is switched with at least one further switching frequency, wherein in the welding phase the at least one further switching frequency corresponds to a further normal switching frequency, in order to transmit energy from the input connection to the output connection.

3 . The method according to claim 2 , wherein the at least one further normal switching frequency corresponds to the normal switching frequency.

4 . The method according to claim 1 , wherein, in the stand-by phase, the at least one further switching frequency is switched with a further stand-by switching frequency lower than the further normal switching frequency.

5 . The method according to claim 4 , wherein the at least one further stand-by switching frequency corresponds to the stand-by switching frequency.

6 . The method according to claim 1 , wherein, in the stand-by phase, the at least one switch element and/or at least one of the further switch elements is deactivated.

7 . The method according to claim 1 , wherein the control signal is made by actuating a switch or button at the intended start or end of the welding.

8 . The method according to claim 1 , wherein the parameter is given by a reduced or increased welding voltage and/or a reduced/increased current flow on the output side.

9 . The method according to claim 1 , wherein the transmitted control signal is transmitted via an interface.

10 . A welding device comprising:
a DC-to-DC converter having an input connection and an output connection, the DC-to-DC converter being configured to convert an input DC voltage present at the input connection into an output DC voltage present at the output connection; and a welding power unit having a power unit input and a power unit output, the output DC voltage being applied to the power unit input and the welding power unit being configured to control the output DC voltage present at the power unit input to a welding voltage present at the power unit output, the DC-to-DC converter comprises at least one switch element in a branch and a control unit, the control unit being designed to switch the at least one switch element in a welding phase with a switching frequency corresponding to a normal switching frequency, in a stand-by phase, in which no arc burns, with a switching frequency corresponding to a stand-by switching frequency that is lower than the normal switching frequency, wherein a transmitted control signal and/or a parameter defined in the welding device effects a switchover from the welding phase into the stand-by phase and/or from the stand-by phase into the welding phase, and wherein the control unit is designed to maintain the output DC voltage during the stand-by phase in order to provide the welding power unit with the output DC voltage required for an optimal start of the welding phase.

11 . The welding device according to claim 10 , wherein the branch comprises an inductor and a freewheeling diode, wherein a first coil terminal of the inductor is connected to the input connection and a second coil terminal of the inductor is connected to a first switch terminal of the switch element and to an anode of the freewheeling diode, wherein a second switch terminal of the switch element is connected to ground and a cathode of the freewheeling diode is connected to the output connection.

12 . The welding device according to claim 11 , wherein the DC-to-DC converter comprises at least one further branch having at least one further switch element, at least one further inductor and at least one further freewheeling diode, wherein, in the at least one further branch, a first coil terminal of the at least one further inductor is in each case connected to the input voltage, and a second coil terminal of the at least one further inductor is in each case connected to a first switch terminal of the at least one further switch element and in each case to an anode of the at least one further freewheeling diode, wherein a second switch terminal of the at least one further switch element is in each case connected to ground, and a cathode of the at least one freewheeling diode is in each case connected to the output connection, and wherein the control unit is designed to switch the at least one further switch element with at least one further switching frequency corresponding to a further normal switching frequency during the welding phase of the welding device.

13 . The welding device according to claim 12 , wherein the control unit is designed to switch the at least one further switch element with a further stand-by switching frequency lower than the further normal switching frequency, in the stand-by phase of the welding device.

14 . The method according to claim 13 , wherein the further stand-by switching frequency corresponds to the stand-by switching frequency.

15 . The welding device according to claim 10 , wherein the control unit is designed to deactivate the at least one switching element and/or at least one of the further switching elements in the stand-by phase of the welding device.

16 . The method according to claim 10 , wherein the transmitted control signal is transmitted via an interface.

Assignees

• Fronius Int Gmbh

Inventors

• Knoll Thomas

Classifications

• H02M1/0032

  Control circuits allowing low power mode operation, e.g. in standby mode · CPC title

• B23K9/1043

  characterised by the electric circuit (B23K9/1012 takes precedence) · CPC title

• H02M3/156 Primary

  with automatic control of output voltage or current, e.g. switching regulators · CPC title

• H02M1/0054

  Transistor switching losses (periodically suspending operation of switching converter in low power mode H02M1/0035) · CPC title

• H02M3/1586

  switched with a phase shift, i.e. interleaved · CPC title