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CN-115336158-B - DC-DC converter for a welding device and method for operating a DC-DC converter for a welding device

CN115336158BCN 115336158 BCN115336158 BCN 115336158BCN-115336158-B

Abstract

According to the invention, in order to reduce the energy consumption of the welding device (1) in the idling operation (L) and to achieve an excellent and controlled start of a welding phase (X), wherein the DC-DC converter (2) of the welding device (1) converts a DC input voltage (Ue) applied to an input terminal (ue+) into a DC output voltage (Ua) applied to an output terminal (ua+), wherein at least one switching element (S1) of one branch (A) of the DC-DC converter (2) is switched at a switching frequency (f 1), wherein a welding phase (X) is provided for the welding device (1), during which the switching frequency (f 1) corresponds to a normal switching frequency (f 1X), and wherein an idling phase (L) is provided for the welding device (1), during which the at least one switching element (S1) is switched at a switching frequency (f 1) corresponding to an idling switching frequency (f 1L), which is smaller than the normal switching frequency (f 1X).

Inventors

  • T. Knoll

Assignees

  • 弗罗纽斯国际有限公司
  • 弗罗纽斯国际有限公司

Dates

Publication Date
20260421
Application Date
20210330
Priority Date
20200331

Claims (16)

  1. 1. Method for operating a welding device (1), wherein a DC-DC converter (2) of the welding device (1) converts a DC input voltage (Ue) applied to an input terminal (ue+) into a DC output voltage (Ua) applied to an output terminal (ua+) which is applied to a power module input of a welding power module (5) of the welding device (1), wherein at least one switching element (S1) of a branch (A) of the DC-DC converter (2) is switched at a switching frequency (f 1), wherein the welding device (1) is provided with a welding phase (X) during which the switching frequency (f 1) corresponds to a normal switching frequency (f 1X), and wherein the welding power module (5) regulates the DC output voltage (Ua) applied to the power module input to the welding voltage (Ua') applied to the power module output in the welding phase (X), characterized in that the welding device (1) is provided with at least one switching element (S1) at a switching frequency (L1) during which the switching frequency (f 1) is at least one idle frequency (f 1) is not present during the idle frequency (L1), the transmitted control signal (S) and/or a parameter (P) specified in the welding device (1) facilitates a transition from the welding phase (X) to the idle phase (L) and/or from the idle phase (L) to the welding phase (X), and During this idle phase (L), a dc output voltage (Ua) is maintained in order to supply the welding power assembly (5) with the dc output voltage (Ua) required for an optimal starting welding phase (X).
  2. 2. Method according to claim 1, characterized in that at least one further switching element (S2, S3) of at least one further branch (B, C) of the dc-dc converter is switched with at least one further switching frequency (f 2, f 3), wherein the at least one further switching frequency (f 2, f 3) corresponds to a further normal switching frequency (f 2X, f 3X) in the welding phase (X) in order to transfer energy from the input terminal (ue+) to the output terminal (ua+).
  3. 3. The method according to claim 2, characterized in that the further normal switching frequency (f 2x, f3 x) corresponds to the normal switching frequency (f 1 x).
  4. 4. A method as claimed in claim 2 or 3, characterized in that the at least one further switching frequency (f 2, f 3) is switched in an idle phase (L) at a further idle switching frequency (f 2L, f 3L) which is smaller than the further normal switching frequency (f 2x, f3 x).
  5. 5. The method according to claim 4, wherein the at least one further idle switching frequency (f 2L, f 3L) corresponds to the idle switching frequency (f 1L).
  6. 6. A method according to claim 2 or 3, characterized in that the at least one switching element (S1) and/or at least one of the further switching elements (S2, S3) is deactivated during the idle phase (L).
  7. 7. The method according to claim 1, characterized in that the control signal (S) is generated by operating a switch or button to start or end the welding as specified.
  8. 8. The method as claimed in claim 1, characterized in that the parameter (P) is given by a reduced or increased welding voltage and/or a reduced/increased current on the output side.
  9. 9. The method according to claim 1, characterized in that the control signal (S) is transmitted via an interface.
  10. 10. A welding device (1) comprising a dc-dc converter (2) and comprising a welding power assembly (5), the dc-dc converter (2) being configured for converting a dc input voltage (Ue) applied at an input terminal (ue+) into a dc output voltage (Ua) applied at an output terminal (ua+) applied at a power assembly input of the welding power assembly (5) of the welding device (1), the dc-dc converter (2) comprising at least one switching element (S1) in one branch (a) and comprising a regulating unit (3), the regulating unit (3) being configured for switching the switching element (S1) in a welding phase (X) of the welding device (1) at a switching frequency (f 1) corresponding to a normal switching frequency (f 1X), and the welding power assembly (5) being configured for regulating the dc output voltage (Ua) applied at the power assembly input to the power assembly input in the welding phase (X) at a power assembly output, the switching frequency (f 1 ') being configured for idling the switching element (S1) in the welding phase (X) at a switching frequency (f 1 ') corresponding to the switching frequency (f 1 ') of the welding device (1), the no-load switching frequency is lower than the normal switching frequency (f 1X), no arc combustion is present in the no-load phase, the transmitted control signal (S) and/or the parameters (P) specified in the welding device (1) are set to facilitate the transition from the welding phase (X) to the no-load phase (L) and/or from the no-load phase (L) to the welding phase (X), and The regulating unit (3) is designed to maintain the DC output voltage (Ua) during the idle phase (L) in order to provide the welding power assembly (5) with the DC output voltage (Ua) required for an optimal start of the welding phase (X).
  11. 11. Welding device (1) according to claim 10, characterized in that the branch (a) comprises an induction coil (L1) and a freewheel diode (D1), wherein a first coil terminal of the induction coil (L1) is connected to an input terminal (ue+) and a second coil terminal of the induction coil (L1) is connected to a first switching terminal of a switching element (S1) and an anode of the freewheel diode (D1), a second switching terminal of the switching element (S1) is connected to a ground (U-) and a cathode of the freewheel diode (D1) is connected to an output terminal (ua+).
  12. 12. Welding device (1) according to claim 11, characterized in that the dc-dc converter (2) comprises at least one further branch (B, C) with at least one further switching element (S2, S3), at least one further induction coil and at least one further freewheeling diode (D), in which at least one further branch (B, C) a first coil terminal of the at least one further induction coil is connected with the input voltage (Ue) respectively, and a second coil terminal of the at least one further induction coil is connected with a respective first switching terminal of the at least one further switching element (S2, S3) and a respective anode of the at least one further freewheeling diode (D2) respectively, wherein a second switching terminal of the at least one further switching element (S2, S3) is connected with a ground wire (U-) respectively, and a cathode of the at least one freewheeling diode (D) is connected with the output terminal (ua+) respectively, and the regulating unit (3) constitutes a normal switching frequency (f) for the at least one further switching element (S2, S3) during the at least one welding phase (f, at least one further switching element (S2, f 2).
  13. 13. Welding device (1) according to claim 12, characterized in that the regulating unit (3) is configured for switching the at least one further switching element (S2, S3) in an idle phase (L) of the welding device (1) with a further idle switching frequency (f 2L, f 3L) that is smaller than the further normal switching frequency (f 2x, f3 x).
  14. 14. Welding device (1) according to claim 12 or 13, characterized in that the adjustment unit (3) is configured for stopping the operation of the at least one switching element (S1) and/or at least one of the further switching elements (S2, S3) in an idle phase (L) of the welding device (1).
  15. 15. Welding device (1) according to claim 10, characterized in that the control signal (S) is transmitted via an interface.
  16. 16. Welding device (1) according to claim 13, characterized in that the further no-load switching frequency corresponds to the no-load switching frequency (f 1L).

Description

DC-DC converter for a welding device and method for operating a DC-DC converter for a welding device Technical Field The invention relates to a method for operating a welding device, wherein a DC-DC converter of the welding device converts a DC input voltage at an input terminal into a DC output voltage at an output terminal, wherein at least one switching element of the DC-DC converter is switched at a switching frequency, wherein a welding phase is provided for the welding device, during which the switching frequency corresponds to a normal switching frequency. The invention further relates to a dc-dc converter for a welding device, wherein the dc-dc converter is designed to convert a dc input voltage at an input terminal into a dc output voltage at an output terminal, wherein the dc-dc converter comprises at least one switching element in one branch and a regulating unit, which is designed to switch the switching element at a switching frequency corresponding to a normal switching frequency during a welding phase of the welding device. The invention further relates to a welding device comprising a DC-DC converter and a welding power assembly, which is designed to regulate a DC output voltage to a welding voltage during a welding phase. Background The dc-dc converter converts a dc input voltage at an input side into a dc output voltage at an output side. In a boost converter (also called boost converter) the dc output voltage is higher than the dc input voltage, and in a buck converter (also called buck converter) the dc output voltage is lower than the dc input voltage. Boost converters are used in particular in the field of welding technology. In welding devices, boost converters are used, for example, as dc-dc converters, which convert a dc input voltage on the input side into a higher dc output voltage on the output side. In this case, during the welding process, energy is transferred from the input side to the output side during a welding phase, wherein the welding phase begins from the ignition of the arc. The output side of the dc-dc converter may be provided with a parallel intermediate circuit capacitor, to which a dc output voltage is present or applied. In particular, in order to provide a sufficient welding voltage for the welding process during the welding phase, a welding power component is connected downstream of the output side of the dc-dc converter, i.e. downstream of the intermediate circuit capacitor. The welding power assembly regulates the dc output voltage to a suitable, preferably potential-separated welding voltage and/or to a welding current, wherein the welding voltage/welding current can be output in a pulsed manner and/or in a continuous manner depending on the desired welding process. Such a welding device is disclosed, for example, in EP 2850725 B1. However, during operation of the welding device, the welding phase is interrupted by an idle phase in which no welding is performed. During this idle phase, a small amount of energy is still transmitted by the dc-dc converter to the welding power assembly connected to the output, for example to operate the control electronics, regulation units, displays, etc. present in the welding device. The energy is lower since there is no arc burning during the idle phase. However, the dc-dc converter is operated both in the welding phase and in the idling phase of the welding device, wherein of course a considerable energy loss is still produced in the dc-dc converter even during the idling phase. Disclosure of Invention It is therefore an object of the present invention to provide a dc-dc converter for a welding device which allows an excellent and controlled start of the welding phase to be achieved. According to the invention, this object is achieved by a method in which the welding device is provided with an idle phase during which the switching element is switched at a switching frequency, which corresponds to an idle switching frequency that is smaller than the normal switching frequency. This object is furthermore achieved by a dc-dc converter, wherein the regulating element is configured for switching the switching element in an idle phase of the welding device at a switching frequency, which corresponds to an idle switching frequency that is smaller than a normal switching frequency. This object is furthermore achieved by a welding device comprising a dc-dc converter according to the invention and comprising a welding power assembly, wherein the welding power assembly is designed to regulate a dc output voltage to a welding voltage during a welding phase. During the welding phase, energy is transferred from the input of the dc-dc converter to the output of the dc-dc converter. Of course, the regulation to the welding voltage is merely exemplary, and naturally the dc output voltage may be regulated such that a welding current is generated, or both a welding voltage and a welding current are generated. In this connection, constant-vo