Abstract:
An explosion vent mounted to seal an opening formed on a wall of a closed space comprises a cover being dimensioned to fit on said opening and having a perimeter with an edge adapted to seal the cover against the opening with a sealing element. A spring element is arranged to hold the cover in the opening and the spring element has a direction of spring action. The cover is held by opposite retaining surfaces in the opening and the cover and he retaining surfaces are acting against the spring action of element. The sealing element is positioned against the opening so that the sealing force is directed at least partially crosswise to the direction of the spring action of the spring element.
Abstract:
A frequency converter (100) comprises a processor (102), memory (104) and basic software (106) in the memory, the execution of which software implements the basic functionality of the frequency converter. For application-specific customization, the memory of the frequency converter is arranged to include application software (108) that contains callable functions (210) and is installable separately from the basic software. The frequency converter is arranged to execute the basic software (106) and the application software (108) with the same processor (102). The basic software (106) calls a function of the application software and/or provides functions of its own to be called by the application software indirectly via a link (240k) in a call table (240), the location of the link in the call table being independent of the location of the function (210) corresponding to the link in the memory.
Abstract:
A capacitor fastening for fastening a capacitor to a panel, whereby the capacitor, when mounted in place, is positioned in the panel, fastened at its lower part. The capacitor fastening includes a retainer in the panel at the mounting point of the capacitor for preventing lateral movement of the capacitor in at least one selected direction; a tightening plate arranged above the panel and to be fastened to the panel, which tightening plate has a hole substantially corresponding to the diameter of the capacitor above the mounting point of the panel; and a wedge between the panel and the tightening plate for tightening the retainer of the panel and the edge of the hole in the tightening plate from opposite directions against the capacitor.
Abstract:
A frequency converter unit includes a unit body, input bus bar means and output bus bar means. The input bus bar means have a plurality of input side bus bars spaced apart in a first direction, and the output bus bar means have a plurality of output side bus bars spaced apart in the first direction, which is perpendicular to an installation direction of the frequency converter unit. Each of the plurality of input side bus bars and the plurality of output side bus bars includes an aperture configured to connect the bus bar to a counterpart contact in a frame with a bolt-nut connection.
Abstract:
A method is provided for optimizing a parameter used in a frequency converter connected to an electrical rotating machine. The method includes identifying a parameter of the machine using electrical quantities, the identified parameter being used in the frequency converter and being identified in a first operating point, providing an electro-mechanical model of the rotating electrical machine to the frequency converter, and calculating when a processor capacity of the frequency converter is available, (i) a state of the rotating electrical machine in the first operating point using a finite element method with the electro-mechanical model of the rotating electrical machine, (ii) a state of the rotating electrical machine in a selected operating point using the finite element method with the electro-mechanical model, correcting the calculated state of the rotating electrical machine, and calculating, from the corrected state, parameter(s) of the electrical machine to be used in the frequency converter.
Abstract:
A method for controlling an electric drive, having an inverter, an electric motor and control means configured in a first operating state of the electric drive to control the electric drive to run in a constant operating point, determine and store a value of an output voltage of the inverter or a value of a flux reference of the inverter, and a value of a switching frequency of the inverter with which a determined input power of the electric drive is lowest. The controller is configured in a second operating state of the electric drive to control the electric drive to use the stored values to run in the operating point.
Abstract:
An exemplary frequency converter and method are directed to estimating an operation point of a pump when the QH characteristic curve of the pump is known. The frequency converter controls the pump, and a process curve is estimated when a first operation point of the pump is in the nominal range. The process curve defines a head as a function of volumetric flow. A rotational speed of the pump is determined and a QH characteristic curve of the pump is converted to a current rotational speed of the pump based on affinity laws. A second operation point of the pump is estimated by determining an intersection point of the converted QH characteristic curve and the estimated process curve.
Abstract:
Exemplary embodiments for controlling a switching branch for a three-level converter, and a switching branch are disclosed. A first semiconductor switch and a second semiconductor switch, a first diode and a second diode, a third semiconductor switch and a fourth semiconductor switch, a third diode, and a fourth diode, a fifth semiconductor switch and a sixth semiconductor switch, a fifth diode, and a sixth diode, and a control arrangement for controlling the semiconductor switches are provided. The first semiconductor switch, the first diode, the fifth semiconductor switch and the fifth diode reside in a first switching branch-specific semiconductor module, and the fourth semiconductor switch, the fourth diode, the sixth semiconductor switch and the sixth diode reside in a second switching branch-specific semiconductor module.