Abstract: A method and arrangement for controlling semiconductor power switches, e.g. IGBTs, in parallel connected power devices, e.g. in frequency converters, wherein the semiconductor power switches connect either the positive or the negative pole of the intermediate DC-voltage of the power device to an output phase of the power device. In the method the voltages of those output phases which are connected in parallel are measured, the timing differences of the output voltage state changes are calculated on the basis of the output voltage measurement results, and the control signals of the semiconductor power switches are advanced or delayed such that the output voltage state changes in the phases which are connected together via output impedances occur at desired time instants.

Abstract: A control device for controlling motion of a load of a carrier device is presented. The carrier device can be for example a crane and the load can be carried with a rope connected to a suspension point of the crane. The control device comprises an input interface for receiving an input signal indicative of a target speed of the load, an output interface for submitting an output signal indicative of a reference speed of the suspension point, and a processing system constituting a signal processing path for producing the output signal based on the input signal. The signal processing path comprises at least one finite impulse response filter for suppressing a signal component whose frequency is the natural swinging frequency of the load. Due to the finite impulse response, the temporal length of settling and tail effects caused by the filter is limited and deterministic.

Abstract: An arrangement for cooling the inside air of an enclosure of a liquid cooled power electronic device, the arrangement comprising an air to liquid heat exchanger attached to the door of an enclosure, and means for circulating the inside air of the enclosure through an air channel of the heat exchanger. The heat exchanger comprises a cooler with internal liquid circulation, assembled inside the air channel and connected to the main liquid circulation of the enclosure, for example by flexible connection pipes, which allow the enclosure door to be opened without disturbing the liquid circulation.

Abstract: Arrangement for controlling a voltage signal between gate and emitter terminals (G-E) of a switch type power semiconductor component, such as an IGBT transistor, such that the voltage signal is formed at least partly by means of a resistance and a switch (RGON1-SGON1, RGOFF1-SGOFF1) connected in series between an auxiliary voltage (+UG4, ?UG4) of a gate controller and the gate terminal (G) of the IGBT. The arrangement is adapted to control the switch (SGON1, SGOFF1) with a high frequency of at least 1 MHz and with a duty cycle adjusted such that the measured rate of change of a collector voltage of the IGBT being controlled is set in accordance with a reference value received from a control unit of the device.

Abstract: Power electronics device, such as a frequency converter, comprising power units (REC1, INU1, INU2, CDC1), a metal frame (31) and a DC bus arrangement in which the power units are connected. The power units may be assembled inside the metal frame (31) wherein the shape of the metal frame is elongated with rectangular cross-sectional shape, consisting of a bottom part (33) and from that essentially vertical oriented side wall parts (32). The DC bus arrangement is arranged on top of the bottom part (33) of the metal frame (31) and separated by an insulator layer (S1) from the metal frame (31). The DC bus arrangement comprises a first DC bus current conductor (DC+) and a second DC bus current conductor (DC?) which are arranged apart from each other. The DC bus current conductors (DC+, DC?) have a flat shape in such a way that their thickness dimension is essentially shorter than their width dimension.

Abstract: An arrangement for fastening, at multiple fastening points, a power electronic device such as a frequency converter (1) to a base (2) susceptible to vibration, at least a portion of which fastening points are vibration-damped, and which fastening points are on two opposite sides of the frequency converter (1). The invention is realized such that there are at least two fastening points (3, 4; 3, 4, 5) on each of two opposite sides of the frequency converter (1), wherein fastening points (3, 4, 5) on one side are damped while fastening points (3, 4) on the other side are undamped.

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: An inverter circuit, coupled to a two-level DC voltage supply and being able to form a five-level output voltage is described, together with a method for operating the inverter circuit. The inverter circuit comprises a series connection of six unidirectional power semiconductor switches, each coupled to an antiparallel diode, between the positive and negative nodes of the supplying DC voltage. The inverter circuit further comprises a series connection of two internal capacitors between the cathodes of the first and the fifth switches of the series connection, the connection point of the capacitors being coupled to the internal node of the inverter circuit. In use, the unidirectional power semiconductor switches are controlled in order to set the voltage of the output of the inverter circuit.

Abstract: Arrangement for cooling, with liquid, one or more electrical devices or structural units of an electrical device that is/are in at least one installation enclosure. A main channeling includes two channels, for distributing the liquid to the electrical devices to be cooled or to the structural units of the electrical devices, a liquid container, which is connected to one of the main channels directly and to the other main channel via a suction channel a pump and a heat exchanger, and also a shut-off valve. The liquid container is disposed below the electrical devices to be cooled or their structural elements, and the amount of liquid to be contained in the arrangement is configured to be such the ends of both the suction channel and the return channel that are inside the liquid container are always situated below the liquid surface.

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 housing arrangement of a power electronics device includes one power module or several identical power modules, each module with at least one part connected to a hazardous voltage, the arrangement further including a housing part having room for at least one power module. Each power module includes an enclosure part which essentially surrounds the power module and includes electrically insulating material. All the external connections of the power module are placed on one single wall of the enclosure part. The power modules and the enclosure part of the power modules are arranged such that when the power module is installed to the housing part the power module is electrically insulated from the housing part and external connections of the power module are directed to the front side of the housing part.

Abstract: DC choke arrangement of a power transformer, especially of a frequency converter, provided with a DC circuit and connected to an AC electricity network, to limit the harmonics of the network current taken by an appliance from the AC network, in which DC choke arrangement is at least one choke (Ldc+, Ldc?), which is arranged in the magnetic core, which contains pillar parts and yoke parts (1a?, 1b?, 2a?, 2b?), in which one or more permanent magnets (51) are arranged in the magnetic core of the choke, and in which the permanent magnet is positioned at an angle with respect to the longitudinal direction of the part or parts of the magnetic core such that the cross-sectional area of the permanent magnet is greater than the cross-sectional area of the part of the magnetic core in question or the parts of the magnetic core in question.