Abstract:
A converter arrangement can include a first rectifier having an AC input and a DC output with two DC output poles, a capacitance (C) connected between the DC output poles of the first rectifier, a second rectifier having an AC input with two AC input poles and a DC output with two DC output poles, wherein the DC output of the second rectifier is connected between the DC output poles of the first rectifier. A magnetic amplifier includes at least one control winding (L2) and at least one AC winding (L11, L12), wherein the at least one control winding is connected between the DC output poles of the first rectifier, and wherein the at least one AC winding (L2) of the magnetic amplifier is connected in series with the AC input of the second rectifier.
Abstract:
An actuator assembly is disclosed, which includes a power unit, an actuator powered by the power unit, the power unit being configured to provide a work motion of the actuator, a motion sensor, a timing unit for measuring an immobility time of the actuator, a safety unit for selectively placing the actuator assembly into an operational state and a safety state in which the work motion of the actuator can be prevented, the safety unit being configured to prevent the operational state of the actuator assembly in case the immobility time of the actuator exceeds a predetermined process safety time. The actuator assembly can include an activation unit configured to control the power unit to provide an activation motion of the actuator in case the immobility time exceeds a predetermined activation time.
Abstract:
A three-level converter and a method for controlling a three-level converter, wherein the third (S31, S32, S33), the fourth (S41, S42, S43) and the fifth (S51, S52, S53) controllable semiconductor switch of a switching branch having, out of all the switching branches, the most positive voltage in its alternating current pole (AC1, AC2, AC3) is controlled to be non-conductive for the whole period of time when the switching branch in question has the most positive voltage in its alternating current pole, and the first (S11, S12, S13), the second (S21, S22, S23) and the sixth (S61, S62, S63) controllable semiconductor switch of a switching branch having, out of all the switching branches, the most negative voltage in its alternating current pole is controlled to be non-conductive for the whole period of time when the switching branch in question has the most negative voltage in its alternating current pole.
Abstract:
Unique systems, methods, techniques and apparatuses of a reverse-conducting IGBT (RC-IGBT) are disclosed. One exemplary embodiment is a circuit comprising a series connection of controllable switch components where at least one of the controllable switch components is an RC-IGBT. The circuit is operated by applying a pre-trigger pulse to the gate electrode of the RC-IGBT during reverse conduction of the RC-IGBT at a first time instant, the pre-trigger pulse corresponding to a turn-on gate pulse. Next, a turn-on gate pulse is applied at a second time instant to the other controllable switch component of the series connection for controlling the other controllable switch component to a conductive state such that the pre-trigger pulse and the turn-on gate pulse overlap, and ending the pre-trigger pulse after a delay time at the third time instant. The delay time is the time period when the turn-on gate pulse and the pre-trigger pulse overlap.
Abstract:
The present disclosure relates to a power semiconductor module comprising a printed circuit board (PCB), and to method of cooling such a power semiconductor module. The module comprises a power semiconductor device and an island of thermally conducting foam embedded into the printed circuit board. The power semiconductor device and the island of thermally conducting foam are positioned on top of each other, and the island is arranged to form a path for a flowing coolant cooling the power semiconductor device.
Abstract:
A method is provided for balancing voltages of a DC link of a multi-level inverter, where the DC link is divided into two halves by a neutral point connection. The method includes injecting a periodic common-mode voltage injection signal to a common-mode voltage reference and a periodic power injection signal to a power reference of the inverter. The power injection signal has the same frequency as the common-mode voltage injection signal. A phase shift between the common-mode voltage injection signal and the power injection signal is constant. The amplitude of at least one of the common-mode voltage injection signal and the power injection signal is controlled on the basis of a difference between voltages over the two halves of the DC link. An apparatus is also provided for implementing the method.
Abstract:
A method and arrangement for determining the flow rate (Q) produced by a pump, when the pump is controlled with a frequency converter, which produces estimates for rotational speed and torque of the pump, and the characteristic curves of the pump are known. The method includes determining the shape of a QH curve of the pump, dividing the QH curve into two or more regions depending on the shape of the QH curve, determining on which region of the QH curve the pump is operating, and determining the flow rate (Q) of the pump using the determined operating region of the characteristic curve.
Abstract:
A method and arrangement are disclosed for a vehicle inverter drive having a voltage distribution block and two or more inverters, intermediate circuits of which are connected in parallel to the voltage distribution block for supplying voltage to the intermediate circuits, in which the intermediate circuits of the inverters are interconnected with a coaxial cable to minimize inductance in the parallel connection.