Abstract: A method for detecting low impedance condition at an output (15) of an electrical converter (10), a control unit (1000), a computer program product, and an electrical converter (10) are presented. The method includes determining (110) a first current value (I1(T1)) of a first current (I1), and a second current value (I1(T2)) of the first current (I1), and determining (120) a first current difference (?I1) between the first (I1(T1)) and the second (I1(T2)) current values, and comparing (130) the first current difference (?I1) to a first current difference threshold (I1_TH), and if the first current difference (?I1) is of predefined magnitude with respect to the first current difference threshold (I1_TH), such as higher, turning off (140) a first voltage (U1) driving the first current (I1), such as by switching off a corresponding switch or switches for applying the first voltage (U1) to the output (15).

Abstract: The present invention relates to a drive for an electric application such as an electric motor, said drive including at least one microphone for registering noise signals occurring at the drive, wherein the microphone is connectable to a computing device for analysing the registered noise signals. The registered noise signals may be used for a maintenance process of the drive and/or a fine-tuning process of a drive control method of the drive. The present invention also relates to a maintenance process, in particular a predictive maintenance process for a corresponding drive. Furthermore, the present invention relates to a process for fine tuning a drive control method of a corresponding drive.

Abstract: A common mode choke (20) for connecting to DC side of a power converter (100). The common mode choke (20) includes a choke core (21) having a first core portion (21A) and a second core portion (21B) for guiding magnetic flux (F). The common mode choke (20) also includes a first winding (24) and a second winding (25) for generating magnetic flux, wherein both of the windings (24, 25) have series-connected first (24A, 25A) and second portions (24B, 25B), respectively. The first portion (4A) of the first winding (24) and the first portion (25A) of the second winding (25) are concentrically around the first core portion (21A), and the second portion (24B) of the first winding (24) and the second portion (25B) of the second winding (25) are concentrically around the second core portion (21B).

Abstract: A DC-link charging arrangement is described having a DC-link capacitor, rectifier means, and contactor means arranged between supply voltage ports and the rectifier means and having at least one contactor. Such a charging arrangement should enable charging of a DC-link capacitor in a simple way with low losses. To this end a charging capacitor is arranged bridging the at least one contactor.

Abstract: The disclosure provides an inductor and a method for producing the same. The inductor includes a first core made of a first magnetic material; at least two windings, configured to be twisted with each other and embedded within the first core, each winding having a pair of terminals extending out of the first core.

Abstract: The disclosure provides an inductor and a method for producing the same. The inductor includes a first core made of a first magnetic material; at least two windings, configured to be twisted with each other and embedded within the first core, each winding having a pair of terminals extending out of the first core.

Abstract: The present invention relates to a drive for an electric application such as an electric motor, said drive including at least one microphone for registering noise signals occurring at the drive, wherein the microphone is connectable to a computing device for analysing the registered noise signals. The registered noise signals may be used for a maintenance process of the drive and/or a fine-tuning process of a drive control method of the drive. The present invention also relates to a maintenance process, in particular a predictive maintenance process for a corresponding drive. Furthermore, the present invention relates to a process for fine tuning a drive control method of a corresponding drive.

Abstract: A method for detecting low impedance condition at an output (15) of an electrical converter (10), a control unit (1000), a computer program product, and an electrical converter (10) are presented. The method includes determining (110) a first current value (I1(T1)) of a first current (I1), and a second current value (I1(T2)) of the first current (I1), and determining (120) a first current difference (?I1) between the first (I1(T1)) and the second (I1(T2)) current values, and comparing (130) the first current difference (?I1) to a first current difference threshold (I1_TH), and if the first current difference (?I1) is of predefined magnitude with respect to the first current difference threshold (I1_TH), such as higher, turning off (140) a first voltage (U1) driving the first current (I1), such as by switching off a corresponding switch or switches for applying the first voltage (U1) to the output (15).

Abstract: A method for pulse-width modulation of a power converter (10) and a power converter (10) are presented. The method comprises determining (110) a modulation index, selecting (120), based on the modulation index, a modulation technique from a plurality of pre-deter-mined modulation techniques, and modulating (130) an output (16) of the power converter (10) by utilizing the selected modulation technique.

Abstract: A method for pulse-width modulation of a power converter (10) and a power converter (10) are presented. The method comprises determining (110) a modulation index, selecting (120), based on the modulation index, a modulation technique from a plurality of pre-determined modulation techniques, and modulating (130) an output (16) of the power converter (10) by utilizing the selected modulation technique.

Abstract: The method for adjusting an inverter (1) connected to an electric motor (2) via a du/dt-filter (3) and a motor cable (4) is described. The method comprises the steps of generating a pulse on the motor cable by means of the inverter (1) measuring a cycle time of a pulse answer from consecutive current peaks, determining a time delay td from the cycle time, determining a dwell time Tdwell to be avoided from the time delay td by Tdwell=k*td, k ? {2, 6, 10, . . . } adjusting the time between consecutive switchings of the inverter (1) to be out of a range from Tdwell?tA to Tdwell+tA wherein tA is an allowable deviation from Tdwell.

Abstract: A DC-link charging arrangement is described having a DC-link capacitor (C4), rectifier means (S17-S22), and contactor means arranged between supply voltage ports (U, V, W) and the rectifier means (S17-S22) and having at least one contactor (13-15). Such a charging arrangement should enable charging of a DC-link capacitor in a simple way with low losses. To this end a charging capacitor (Cch1-Cch3) is arranged bridging the at least one contactor (13-15).

Abstract: A filtering arrangement for a system including a power electronics device and an external power storage/discharge element, which power electronics device includes a power module and a three-phase filter between the AC power terminals of the power module and the supplying AC power grid, and which power module includes a DC intermediate power bus, and which three-phase filter between the AC power terminals and the supplying AC power grid includes two three-phase inductors, and which external power storage/discharge element has two DC power terminals which are connected to the DC intermediate power bus of the power electronics device. The filtering arrangement includes a common mode inductor which is connected between the DC power terminals of the external power storage/discharge element and the terminals of the DC intermediate power bus of the power module.

Abstract: A method and apparatus for the adaptation of a motor drive system is described. The method includes applying a small signal frequency sweep to a motor drive system wherein the motor drive system includes an inverter, an output filter (e.g. a sine filter) and a motor, acquiring frequency response data in response to said frequency sweep and setting parameters of the motor drive system depending on the acquired frequency response data.

Abstract: The method for adjusting an inverter (1) connected to an electric motor (2) via a du/dt-filter (3) and a motor cable (4) is described. The method comprises the steps of generating a pulse on the motor cable by means of the inverter (1) measuring a cycle time of a pulse answer from consecutive current peaks, determining a time delay td from the cycle time, determining a dwell time Tdwell to be avoided from the time delay td by Tdwell=k*td, k ? {2, 6, 10, . . . } adjusting the time between consecutive switchings of the inverter (1) to be out of a range from Tdwell?tA to Tdwell+tA wherein tA is an allowable deviation from Tdwell.

Abstract: The disclosure provides an inductor and a method for producing the same. The inductor includes a first core made of a first magnetic material; at least two windings, configured to be twisted with each other and embedded within the first core, each winding having a pair of terminals extending out of the first core.

Abstract: A power electronic converter comprises controllable switches (104-109) and a control system (110) for operating the controllable switches. The control system is configured to control the controllable switches so as to produce at least one test voltage pulse. The power electronic converter comprises a voltage sensor (111) for detecting a reflected voltage that is caused by a reflection of the test voltage pulse in an electric system connected to the power electronic converter. The control system is configured to control the operation of the power electronic converter at least partly in accordance with information based on the detection of the reflected voltage. The information can be used for example for determining forbidden voltage pulse lengths which would cause reflection-based over-voltages and/or for detecting faults such as short circuits and earth faults.

Abstract: A filtering method and arrangement for a system comprising a regenerative frequency converter and a motor, which regenerative frequency converter has an intermediate DC circuit comprising positive and negative pole and which regenerative frequency converter is connected to a supplying 3-phase mains network via a line filter unit comprising in serial connection a first 3-phase inductor unit with mains side terminals and motor side terminals and a second 3-phase inductor unit, and a 3-phase capacitor unit which comprises phase-specific capacitors which are connected in star connection between the motor side terminals of the first 3-phase inductor unit and a star point, which star point is connected to ground via a fourth capacitor. The filtering arrangement further comprises a common mode inductor unit and a filtering capacitor unit.

Abstract: A power electronic converter comprises controllable switches (104-109) and a control system (110) for operating the controllable switches. The control system is configured to control the controllable switches so as to produce at least one test voltage pulse. The power electronic converter comprises a voltage sensor (111) for detecting a reflected voltage that is caused by a reflection of the test voltage pulse in an electric system connected to the power electronic converter. The control system is configured to control the operation of the power electronic converter at least partly in accordance with information based on the detection of the reflected voltage. The information can be used for example for determining forbidden voltage pulse lengths which would cause reflection-based over-voltages and/or for detecting faults such as short circuits and earth faults.

Abstract: A filtering method and arrangement for a system comprising a regenerative frequency converter and a motor, which regenerative frequency converter has an intermediate DC circuit comprising positive and negative pole and which regenerative frequency converter is connected to a supplying 3-phase mains network via a line filter unit comprising in serial connection a first 3-phase inductor unit with mains side terminals and motor side terminals and a second 3-phase inductor unit, and a 3-phase capacitor unit which comprises phase-specific capacitors which are connected in star connection between the motor side terminals of the first 3-phase inductor unit and a star point, which star point is connected to ground via a fourth capacitor. The filtering arrangement further comprises a common mode inductor unit and a filtering capacitor unit.