Abstract: The present invention relates to a variable speed drive for driving an electric motor and providing a safe torque off (STO) function. The drive includes two parallel signal buffers connected to a safety controller and at least one IGBT gate driver circuit, wherein the signal buffers share the same IGBT gate control signals as inputs and feed them to the same IGBT gate driver circuits and wherein each signal buffer has an own STO control signal for activation and deactivation of outputs. The invention is also directed at a method for diagnosing a corresponding drive.

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: The invention relates to methods for providing a pulse-width modulated power signal in which control signals are used to define phase states and duration. The invention further relates to a corresponding node and to a corresponding system.

Abstract: An electronic appliance such as a low harmonic drive, an active rectifier, a grid converter or any active front end or grid converter with an LCL filter. The converter is a two-level, a three-level or a multilevel inverter. The electronic appliance includes an LCL filter on a grid side of the electronic appliance and an active front end rectifier provided on a load side of the electronic appliance. The LCL filter includes grid side inductors and an active front end rectifier is connected to the LCL filter. A method for damping a corresponding electronic appliance is also disclosed.

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: An electric system for transmitting serial communication messages with different priorities over a communication link. The data to be transmitted is arranged in serial communication messages comprising a start of packet (SOP) symbol and data symbols. The ongoing transmission of a first message is interrupted if a SOP symbol of a second message is sent before the first message has been completed. Transmission of the first message is continued only after the second message has been sent.

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 resonance damping element for a power converter having a positive busbar and a negative busbar, wherein the resonance damping element comprises a magnetic core formed with two openings through which the positive busbar and the negative busbar of the power converter are to be routed, respectively.

Abstract: A method for a direct current (DC) power distribution arrangement and a direct current (DC) power distribution arrangement, comprising a plurality of DC power distribution subsystems. Each DC power distribution subsystem comprises an inverter unit (INU) configured to operate as a subsystem-specific circuit breaker for intercoupling/separating the DC power distribution subsystem to/from the rest of the DC power distribution arrangement.

Abstract: A controller (203) comprises a processing system (205) for controlling a power electronic converter during a short circuit taking place in a direct voltage side of the power electronic converter. The processing system recognizes a direction of current in a phase (126-128) of an alternating voltage side of the power electronic converter, sets a high-leg controllable switch (108-110) of the phase to a conductive state while keeping a low-leg controllable switch (111-113) of the phase in a non-conductive state when the recognized direction of the current is outwards from the power electronic converter, and otherwise sets the low-leg controllable switch to the conductive state while keeping the high-leg controllable switch in the non-conductive state. Thermal loadings of freewheeling diodes (114-119) of the power electronic converter are reduced since currents needed to burn input fuses (122) of the power electronic converter are shared between the controllable switches and the freewheeling diodes.

Abstract: A filter arrangement in connection with a power converter for transferring power between a multiphase AC voltage network and a DC voltage network. The filter arrangement comprises a differential mode coil coupled between each AC terminal of an inverter bridge and corresponding AC network phase terminal, and a common mode coil coupled between each inverter bridge DC terminal and corresponding DC network terminal. Both inductors are located in the same magnetic core structure such that each of the differential mode winding is wound around its own phase-specific core leg and all common mode windings are wound around their own single core leg. The winding direction of both AC- and DC-side inductor windings is such that a common-mode current which flows along both inductors in the same direction, induces in each magnetic core leg a flux which reinforces the total flux circulating in the magnetic core.

Abstract: A converter circuitry between a first network, which may be either a poly-phase medium-voltage alternating current (AC) network, at least one polyphase low-voltage AC network or at least one direct-current (DC) network, and a second network, which may be either a polyphase medium-voltage AC network or a medium-voltage DC network, wherein the converter circuitry comprises at least one power bus and low-voltage power cells both at the first and at the second network side such that each power cell is connected to a power bus via a transformer. Each power bus is connected to a low-voltage power unit, which is able to supply pre-charging power via the power bus to all power cell intermediate DC-link filtering capacitors before the converter is started. The low-voltage power unit is also able to take care of a resistor braking in case the first network cannot take the power supplied by the load connected to the second network.

Abstract: An electronic circuit includes: a first series-connection of DC link capacitors (CA1, . . . , CAm) and a second series-connection of DC link capacitors (CB1, . . . , CBn) connected in parallel between DC bus bars (DC+, DC?), wherein the first series has a first node (A) between the DC link capacitors thereof and the second series has a second node (B) between the DC link capacitors thereof; and a short-circuit module (301; 401, 407) configured to receive a voltage difference (UM) between the first node and the second node and to cause the DC bus bars short circuited in response to the received voltage difference being greater than a predetermined threshold.

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 safety circuit coupled between a first direct current (DC) circuit and a second DC circuit, wherein the first DC circuit supplies power to the second DC circuit. The safety circuit comprises a first series connection between positive poles of the first and second DC circuits (the first series connection comprising a first diode, a second diode and a first controllable switch), a second series connection between negative poles of the first and second DC circuits (the second series connection comprising a third diode, a fourth diode and a second controllable switch), a first energy storage device (coupled between the positive pole of the second DC circuit and the first terminal of the second controllable switch), and a second energy storage device (coupled between the negative pole of the second DC circuit and the first terminal of the first controllable switch).

Abstract: A device for estimating inductances of an electric machine having a salient-pole rotor is presented. The device comprises a processing system that controls stator voltages to constitute a balanced multi-phase alternating voltage when the rotor is stationary. The processing system estimates a position of the rotor based on a negative sequence component of stator currents. To estimate the quadrature-axis inductance, the processing system controls direct-axis current to be direct current and quadrature-axis voltage to be alternating voltage. The quadrature-axis inductance is estimated based on the quadrature-axis alternating voltage and on quadrature-axis alternating current. To estimate the direct-axis inductance, the processing system controls direct-axis voltage to be alternating voltage and the quadrature-axis voltage to be zero. The direct-axis inductance is estimated based on the direct-axis alternating voltage and on direct-axis alternating current.

Abstract: An electric system comprising communication link between a signal transmitting end and a signal receiving end, wherein, at the signal transmitting end, a number of data bits are integrated into a low frequency signal to form an integrated signal. Each data bit is transmitted as part of a symbol. Each symbol comprises a predefined number of bits encoding at least one data bit, the state of some of the bits of each symbol being dependent on the state of the low frequency symbol.

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 present invention relates to a method for reducing common mode current in power electronic equipment comprising two or more active front end (AFE) components (1) coupled in parallel between an AC supply grid (2) and a DC-link (3). A duty cycle of pulse width modulation (PWM) for the AFE components (1) is determined, and an error signal is derived based on the determined duty cycle of PWM and on a common mode current of the AFE components (1). A correction voltage is derived, based on the error signal, and a DC voltage control signal is derived based on the derived correction voltage and a measured DC voltage of the DC-link (3) and/or a DC voltage reference. The power electronic equipment is controlled in accordance with the derived DC voltage control signal. The present invention also relates to a method for starting active front end (AFE) components (1) of power electronic equipment comprising two or more AFE components (1) coupled in parallel between an AC supply grid (2) and a DC-link (3).

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.