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 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 method and an arrangement for limiting the interference to a common electric power network, generated by a power electronics device, e.g. a frequency converter, which power electronics device comprises of at least one switch type component being able to change the output voltage value at a predefined permissible switching frequency range. The method comprises scanning through the permissible switching frequency range, recording measured common mode current values as a function of the switching frequency, and setting the final switching frequency of the switch type component out of a value where a local maximum value of the common mode current has been recorded.

Abstract: A method and an arrangement for limiting the interference to a common electric power network, generated by a power electronics device, e.g. a frequency converter, which power electronics device comprises of at least one switch type component being able to change the output voltage value at a predefined permissible switching frequency range. The method comprises scanning through the permissible switching frequency range, recording measured common mode current values as a function of the switching frequency, and setting the final switching frequency of the switch type component out of a value where a local maximum value of the common mode current has been recorded.

Abstract: Apparatus for transferring power between an electricity network (UP) operating on alternating-current electricity and a multiphase electric machine (M2, M3), which apparatus comprises low-voltage power cells (CS, C11 . . . CN6) operating on a cascade principle, which power cells comprise a single-phase output connector (OUT), and at least one transformer (TA, T1 . . . TN), comprising for each power cell connected to it a single-phase or multiphase winding dedicated to the specific power cell, which transformer comprises at least one additional winding (WA, WB1 . . . WBN) connected to the same magnetic circuit as the other windings for the purpose of at least one auxiliary circuit, which can be connected to the aforementioned additional winding.

Abstract: A converter includes a converter bridge (101) adapted to transfer electrical energy between the AC terminal (102) and the DC terminal (103) of the converter. The converter also includes electrical paths bypassing the converter bridge for conducting overvoltage transients occurring in the AC terminal around the converter bridge to the DC terminal. Each electrical path includes a unidirectionally conductive semiconductor component (104a, 104b, 104c), such as a diode, and a voltage-limiting component (105) for which the ratio of voltage change to current change is small when the voltage of the voltage-limiting component is greater than a predetermined threshold voltage. Because of the overvoltage protection thus achieved, AC chokes can be omitted from the AC terminal or at least they can be designed smaller, reducing the load-dependent voltage drop of the DC terminal.

Abstract: Apparatus for transferring power between an electricity network (UP) operating on alternating-current electricity and a multiphase electric machine (M2, M3), which apparatus comprises low-voltage power cells (CS, C11 . . . CN6) operating on a cascade principle, which power cells comprise a single-phase output connector (OUT), and at least one transformer (TA, T1 . . . TN), comprising for each power cell connected to it a single-phase or multiphase winding dedicated to the specific power cell, which transformer comprises at least one additional winding (WA, WB1 . . . WBN) connected to the same magnetic circuit as the other windings for the purpose of at least one auxiliary circuit, which can be connected to the aforementioned additional winding.