Abstract: A control unit for an active filter for reducing resonance in an electric system is provided. The electric system comprises a power source distributing an alternating current to an AC conductor connected to a power consuming unit for distributing the AC to the power consuming unit. The active filter comprises a DC power source and a DC conductor connecting the DC power source to the AC conductor. The control unit comprises: a voltage measurement unit adapter to create a voltage signal on the basis of a measured voltage; a computing unit adapted to compute, using a biquadratic filter, a first compensating current on the basis of the voltage signal for reducing resonance in the electric system and a switching system placed between the DC power source and the DC conductor for creating the calculated first compensating current.

Abstract: A control unit for an active filter for reducing resonance in an electric system is provided. The electric system comprises a power source distributing an alternating current to an AC conductor connected to a power consuming unit for distributing the AC to the power consuming unit. The active filter comprises a DC power source and a DC conductor connecting the DC power source to the AC conductor. The control unit comprises: a voltage measurement unit adapter to create a voltage signal on the basis of a measured voltage; a computing unit adapted to compute, using a biquadratic filter, a first compensating current on the basis of the voltage signal for reducing resonance in the electric system and a switching system placed between the DC power source and the DC conductor for creating the calculated first compensating current.

Abstract: A control unit for an active filter for reducing resonance in an electric system is provided. The electric system comprises a power source distributing an alternating current to an AC conductor connected to a power consuming unit for distributing the AC to the power consuming unit. The active filter comprises a DC power source and a DC conductor connecting the DC power source to the AC conductor. The control unit comprises: a voltage measurement unit adapter to create a voltage signal on the basis of a measured voltage; a computing unit adapted to compute, using a biquadratic filter, a first compensating current on the basis of the voltage signal for reducing resonance in the electric system and a switching system placed between the DC power source and the DC conductor for creating the calculated first compensating current.

Abstract: The present invention relates to a coil (1) for an inductor (6), comprised by metal wire (2) wound circular around a centre axis (C), wherein the wire has an electrically insulating layer (3) insulating each turn of the wire in the winding from neighbouring turns, the shape of the complete winding, building up the coil (1), is substantially toroidal having a substantially elliptic cross section, wherein the thermal heat conductivity is above 1 W/m*K more preferably above 1.2 and most preferably above 1.5. The invention further relates to a magnetic core (7) suitable for an inductor (6), where in the core is made of a soft magnetic composite material made of metallic particles and a binder material, said particles are in the range of 1 ?m-1000 ?m, particles that are larger than 150 ?m are coated with a ceramic surface to provide particle to particle electrical insulation, wherein the volume of magnetic, metallic particles to total core volume is 0.5-0.9.

Abstract: A coil may include a metal wire wound circular around a center axis. The wire may have an electrically insulating layer insulating each turn of the wire in the winding from neighbouring turns. The shape of the complete winding, building up the coil, may be toroidal having an elliptic cross section in a plane perpendicular to a wire winding direction. And the wound coil may have a metal volume to total volume at a level so that the thermal heat conduction of the coil is above 0.8 W/m*K. A method for producing such a coil may involve applying the insulating layer to the wire. The wire may be wound around the center axis. The winding may be compressed to a toroidal shape.

Abstract: A control unit for an active filter for reducing resonance in an electric system is provided. The electric system comprises a power source distributing an alternating current to an AC conductor connected to a power consuming unit for distributing the AC to the power consuming unit. The active filter comprises a DC power source and a DC conductor connecting the DC power source to the AC conductor. The control unit comprises: a voltage measurement unit adapter to create a voltage signal on the basis of a measured voltage; a computing unit adapted to compute, using a biquadratic filter, a first compensating current on the basis of the voltage signal for reducing resonance in the electric system and a switching system placed between the DC power source and the DC conductor for creating the calculated first compensating current.

Abstract: A control unit for an active filter for reducing resonance in an electric system is provided. The electric system comprises a power source distributing an alternating current to an AC conductor connected to a power consuming unit for distributing the AC to the power consuming unit. The active filter comprises a DC power source and a DC conductor connecting the DC power source to the AC conductor. The control unit comprises: a voltage measurement unit adapter to create a voltage signal on the basis of a measured voltage; a computing unit adapted to compute, using a biquadratic filter, a first compensating current on the basis of the voltage signal for reducing resonance in the electric system; and a switching system placed between the DC power source and the DC conductor for creating the calculated first compensating current.

Abstract: A resonant power converter comprising electrical safety components comprising a combination of a diodes and a zener diodes coupled between DC conductors and an auxiliary switching circuit, the diodes being adapted to hinder the current from flowing from the auxiliary switching circuit to the negative DC conductor, and the zener diodes being adapted to allow current to flow from the negative DC conductor to the auxiliary switching circuit when the potential difference between the negative DC conductor and the phase conductor is above a threshold voltage. The Zener diodes being selected such that the threshold voltage of the Zener diodes is below the maximum blocking voltage of the transistors.

Abstract: A resonant power converter includes a DC power source, a positive DC conductor, a negative DC conductor, a phase conductor, and a power converting unit between the DC power source and phase conductor. The power converting unit includes a first switch between the positive DC conductor and phase conductor, a first diode in parallel with the first switch, a second switch between the negative DC conductor and phase conductor, and a second diode in parallel with the second switch. The resonant power converter includes a resonant auxiliary switching circuit between the DC power source and phase conductor. The resonant auxiliary switching circuit includes an inductor in series with a control means, and auxiliary diodes in series with the control means. The inductor is a current discriminating inductor adapted to become saturated by currents flowing through the inductor during normal operation such that the inductance of the inductor is reduced.

Abstract: A resonant power converter is provided. The resonant power converter comprises a balancing circuit for balancing the voltage in a feeding connection. The balancing circuit comprises: a first positive control means in series with an inductor, wherein the first positive control means and the inductor is coupled between the positive DC conductor and the feeding connection, and a second negative control means in series with the inductor, wherein the second negative control means are coupled between the negative DC conductor and the feeding connection. The first positive and second negative control means are adapted to be alternatingly switched on and off for balancing the resonant power converter, such that the voltage in the feeding connection is substantially the mean voltage of the positive DC conductor and the negative DC conductor.

Abstract: A resonant power converter is provided. The resonant power converter comprises a balancing circuit for balancing the voltage in a feeding connection. The balancing circuit comprises: a first positive control means in series with an inductor, wherein the first positive control means and the inductor is coupled between the positive DC conductor and the feeding connection, and a second negative control means in series with the inductor, wherein the second negative control means are coupled between the negative DC conductor and the feeding connection. The first positive and second negative control means are adapted to be alternatingly switched on and off for balancing the resonant power converter, such that the voltage in the feeding connection is substantially the mean voltage of the positive DC conductor and the negative DC conductor.

Abstract: A resonant power converter includes a DC power source, a positive DC conductor, a negative DC conductor, a phase conductor, and a power converting unit between the DC power source and phase conductor. The power converting unit includes a first switch between the positive DC conductor and phase conductor, a first diode in parallel with the first switch, a second switch between the negative DC conductor and phase conductor, and a second diode in parallel with the second switch. The resonant power converter includes a resonant auxiliary switching circuit between the DC power source and phase conductor. The resonant auxiliary switching circuit includes an inductor in series with a control means, and auxiliary diodes in series with the control means. The inductor is a current discriminating inductor adapted to become saturated by currents flowing through the inductor during normal operation such that the inductance of the inductor is reduced.

Abstract: A method for scheduling of periodic real time processes in an operating system, comprising the steps of defining a reference point in time for a periodic real time process, and scheduling the periodic real time process from the reference point in time. Preferably a future point in time is defined as the reference point in time at the start up of the operating system. The real time process is preferably a periodic control process during which a relative control point in time, counted from the beginning of the subsequent control cycle, is calculated during each cycle with absolute time correction counted from the reference point in time. The absolute time correction corresponds to the period of the periodic process multiplied with the number of passed control periods until the beginning of the subsequent control cycle, at which the absolute control point in time is calculated through an addition of the relative control point in time with the absolute time correction.

Abstract: An active filter (4) for compensation of variations in an apparatus' (3) current consumption from a power grid (1) as a cause of variations in the apparatus electrical load, through active frequency filtering and dynamic compensation of reactive energy/current. For each of the power grid's phases (a, b, c) the active filter includes a transistor bridge (Ta, Tb, Tc) connected between each phase and a DC-link (7). The active filter includes a filter circuit of LCL-type, arranged to reduce disturbances on the power grid caused by the active filter itself. The active filter further includes a control device (9) for calculating, with a given working frequency (f), points in time at which the transistor bridges are set to reverse the current direction through the DC-link, and the filter circuit is preferably adjusted to that working frequency.