Abstract:
A method for monitoring a change in a capacitance of an AC filter in an electric system, and an electric system comprising a converter (10), an AC filter (20) comprising at least one capacitance and being connected to the AC output of the converter, switching means (K) connected to an output of the AC filter, and control means (11) configured to control the switching means to open circuit the output of the AC filter, supply by the converter (10) an AC voltage with a predetermined magnitude and a predetermined frequency from the AC output of the converter to the AC filter, monitor a current or currents flowing through the AC output of the converter as a result of the AC voltage supplied to the AC filter, and determine on the basis of the monitored current or currents a change in the at least one capacitance of the AC filter.
Abstract:
A method of determining condition of filter capacitance of a filter connected to the phases of a converter and adapted to be connected to an alternating voltage source (12) and a converter. The converter comprising parallel converter legs having upper (T1, T2, T3) and lower semiconductor switches (T4, T5, T6) with antiparallel connected diodes (D1, D2, D3, D4, D5, D6) connected in series between positive and negative buses (DC+, DC-), wherein the points between the upper and lower semiconductor switches form the phases (a, b, c) of the converter. The filter comprising inductive components (L c,a , L c,b , L c,c ) and capacitors (C ab , C bc , C ca ), the inductive components being connected to the phases of the converter and the capacitors connecting the other ends of the inductive components. The method comprises charging the capacitors of the filter, controlling the semiconductor switches of the converter for short circuiting the capacitors through the inductive components while the filter is disconnected from the alternating voltage source, measuring a current or a voltage in the circuit, determining from the oscillation of the measured current or voltage the condition of the capacitors of the filter.
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 computerized method is disclosed in which an automation device stores (201), in a parameter storage, application-related parameters, each parameter uniquely identifying a specific automation device application. The automation device also stores (202), in an application repository, automation device applications as separate computer program entities. The automation device may detect (203) a pre-determined act performed by a user, the predetermined act comprising the user selecting via a user interface an application-related parameter among the application-related parameters stored in the parameter storage. Based on the detecting (203), the automation device retrieves (204), from the application repository to an execution memory, the automation device application corresponding to the selected application-related parameter, wherein the retrieved automation device application is executable from the execution memory, in order to drive the automation device for an application-related purpose.
Abstract:
A power electronic assembly comprising a power electronic module incorporating multiple of semiconductor power electronic switch components, the power electronic module comprising a base plate, a vapour chamber having one or more condenser pipes in fluid communication with the vapour chamber, the vapour chamber and the one or more condenser pipes forming a closed volume and enclosing a working fluid, a mounting plate having an indent for receiving the vapour chamber and one or more apertures for receiving the one or more condenser pipes, wherein the power electronic module is attached to the mounting plate to transfer heat from the base plate of the power electronic module to the vapour chamber.
Abstract:
The invention relates to a cooling apparatus (1) comprising tubes (4) containing a plurality of channels (8), a first manifold (2) and a second manifold (3) in the second end (7) which provides a fluid path between predetermined channels (8) of the tubes (4). In order to obtain a cooling apparatus providing excellent cooling, the first (2) and second (3) manifolds are solid blocks providing channel loops (10, 11), and the channels (8) of the tubes (4) are connected by the channel loops (10, 11) to other predetermined channels (8) of the tubes (4).
Abstract:
A method of determining operation characteristics of a screw compressor drive and a screw compressor drive, the method comprising pressurising a pressure vessel of the screw compressor with a variable rotational speed of the screw compressor, the rotational speed of the screw compressor having a speed profile in which the rotational speed is changed stepwise such that between stepwise changes the rotational speed of the screw compressor is kept substantially constant for a time period, repeating the speed profile until the pressure of the pressure vessel reaches a set pressure value, determining pressure of the pressure vessel, power consumption of the screw compressor drive and mass flow rate during the pressurising when the rotational speed of the screw compressor is kept substantially constant, calculating energy efficiency of the screw compressor drive as a function of pressure of the pressure vessel and rotational speed of the screw compressor on the on the basis of the determined pressure of the pressure vessel and power consumption of the screw compressor drive.
Abstract:
The present disclosure describes a method and an apparatus (11) for monitoring performances of machines (10) in an arrangement comprising a plurality of machines. The machines each produce event information (e 1 ...e m ), and event history entries are generated into at least one event history collection on the basis of the event information produced by the machines. The at least one event history collection (13) is analysed to find behavioural events of the machines, and computational distances between the machines are determined on the basis of the basis of the found behavioural events. The performances (P 1 ...P n ) of the machines are quantified on the basis of the calculated computational distances.