Abstract:
An exemplary propulsion arrangement is disclosed which includes two propulsion units situated side by side at the stern of a ship at opposite sides of a center line of the hull of the ship. Each propulsion unit can include a hollow support structure attached to the hull, a chamber attached to the support structure, an electric motor within the chamber, a propeller connected through a shaft to the electric motor, and a pivotably supported rudder at the rear end of the chamber. Each propulsion unit can be mounted in a toe-out position forming a horizontal tilt angle (β) of 0.5 to 6 degrees to the center line (CL) of the hull.
Abstract:
A method and apparatus are provided for balancing currents of two or more parallel-connected power semiconductor switches during an on-state of the switches. A control terminal of each switch is driven by a driver unit. The method includes determining ratios between the currents through the switches. For each switch, the method includes controlling the voltage at the control terminal on the basis of the ratios by controlling a level of a supply voltage of the driver unit of the switch, and after a turn-on commutation transient, modulating the output of the driver unit. The duty cycle of the modulation is controlled to minimize the time required for the transition of the voltage at the control terminal from the one voltage level to another.
Abstract:
A method and arrangement are disclosed for operating a pump in pump system having a photovoltaic panel system, an inverter electrically connected to the photovoltaic panel system, and a motor driving the pump and electrically connected to the output of the inverter. The method can include setting a voltage limit for the inverter, monitoring the voltage produced by the photovoltaic panel system, operating the inverter for rotating of the motor when the voltage produced by the photovoltaic panel system is above the voltage limit, and disabling use of the inverter when the voltage of the photovoltaic system remains below the voltage limit.
Abstract:
An exemplary movable contact for an electric switch having a first contact blade and a second contact blade. Each of the first contact blade and the second contact blade includes an assembly hole. The movable contact having an assembly pin wherein the assembly pin includes a separation portion having a diameter greater than the assembly holes of the first and second contact blades thereby keeping the first and second contact blades separated from each other. The assembly pin includes a contact blade portion on each side of the separation portion for insertion to the assembly holes of the contact blades.
Abstract:
An exemplary electric switch mounting arrangement includes a housing and a stationary contact to be mounted to an aperture in a wall of the housing. The arrangement having a compensation component within the interior area of the aperture for allowing stationary contacts of two different sizes to be mounted to the aperture, which compensation component includes one or more projections formed on the housing or the stationary contact and/or one or more recesses formed on the housing or stationary contact for receiving the one or more projections.
Abstract:
An arc quenching plate for an electric switch includes a first mounting portion and a second mounting portion for mounting the quenching plate to respective recesses of the switch. The first mounting portion and the second mounting portion have a different form when compared to each other.
Abstract:
An electric switch includes a movable contact, a stationary contact to be contacted by the movable contact, one or more quenching plates, and a permanent magnet for directing an arc, which is formed when the contacts are separated from each other, to the quenching plate. The quenching plate has a base portion and side portions extending away from the base portion. The permanent magnet is arranged such that the arc is directed towards one of the side portions of the quenching plate.
Abstract:
A user interface of frequency converter over a wireless connection is disclosed. The frequency converter can be connected to a mobile communications device over a short range wireless connection. The mobile communications device can be connected to a wide area network to a service center maintaining information associated with frequency converters. Operational information of the frequency converter can be relayed to the service center over the wide area network as a view of the frequency converter user interface. The frequency converter can be controlled by control commands from the mobile communications device, the control commands being determined based on selections received from the service center, in response to the view conveyed to the service center.
Abstract:
A control system for semiconductor switches, the control system (CTRL) being configured to calculate an estimate of the instantaneous dissipation power of at least one semiconductor component unit (SU1) during an analysis period, whereby the at least one semiconductor component unit (SU1) includes at least one semiconductor switch (S1), and the instantaneous dissipation power includes the conduction losses and switching losses of the at least one semiconductor component unit (SU1).
Abstract:
A cooling assembly includes a device chamber, a cooling chamber separated from the device chamber, a heat exchanger, a device chamber fan arrangement and a control unit. The heat exchanger includes a first portion located in the device chamber and a second portion located in the cooling chamber for transferring heat from the device chamber to the cooling chamber. The device chamber fan arrangement is configured to generate a device chamber cooling medium flow including a first partial flow interacting with the first portion of the heat exchanger. The cooling assembly also includes a first throttle arrangement for regulating the first partial flow. The control unit is configured to reduce a cooling power of the heat exchanger as a response to predetermined operating conditions by decreasing the first partial flow with the first throttle arrangement.