Abstract: A configuration tool for configuring a frequency converter includes an interface with connector poles for connecting the configuration tool to the frequency converter and feeding configuration data from the configuration tool to the frequency converter. To facilitate the configuration of an unelectrified frequency converter, the configuration tool includes a battery or an electromagnetic field generator for conveying the energy required for electrifying at least the memory of the frequency converter to the frequency converter during the configuration.

Abstract: A method and arrangement for measuring output phase currents of a voltage source inverter when the inverter is connected to a load, the method comprising, during commissioning of a drive, the steps of forming consecutive voltage pulses to the load by using the inverter, measuring current of a DC bus for each consecutive pulse such that for each consecutive pulse, a time difference between a current measurement instant and a start of a voltage pulse is changed, removing a value of DC current from measured current samples to obtain sample values for stray current, storing the sample values of the stray current and their time instants with respect to the start of respective voltage pulses, the method further comprising during the use of the inverter the following steps of, measuring DC-bus current, determining an output phase current of the inverter from the measured DC-bus current and from the stored stray current samples.

Abstract: The invention relates to a method and an apparatus to control a propulsion drive. The propulsion drive comprises at least one first propeller drive, which rotates the first propeller and by which the propulsion power and/or rotating speed of the first propeller, and a second propeller drive, by which the second propeller is rotated and controlled. According to the invention the propulsion drive is controlled by a single control command, whereby it is generated from the control command a first control signal, by which the first propeller drive is controlled, and a second signal, by which the second propeller drive is controlled.

Abstract: A frequency converter assembly comprising a direct-voltage circuit and brake chopper means, the direct-voltage circuit including a first branch (DC+) and a second branch (DC?), and the brake chopper means including a first terminal (BRK+), a second terminal (BRK?), a brake chopper switch (S1) and control means (2). The brake chopper switch (S1) is arranged in its closed position to provide a braking connection, in which the first branch (DC+) is electrically connected to the first terminal (BRK+) and the second branch (DC?) is electrically connected to the second terminal (BRK?). The assembly is provided with a first operating state where the control means (2) are arranged to control the brake chopper switch (S1) selectively to the closed position and the open position in response to the desired power supply direction of the direct-voltage circuit.

Abstract: A frequency converter assembly comprising a direct-voltage circuit and brake chopper means, the direct-voltage circuit including a first branch (DC+) and a second branch (DC?), and the brake chopper means including a first terminal (BRK+), a second terminal (BRK?), a brake chopper switch (S1) and control means (2). The brake chopper switch (S1) is arranged in its closed position to provide a braking connection, in which the first branch (DC+) is electrically connected to the first terminal (BRK+) and the second branch (DC?) is electrically connected to the second terminal (BRK?). The assembly is provided with a first operating state where the control means (2) are arranged to control the brake chopper switch (S1) selectively to the closed position and the open position in response to the desired power supply direction of the direct-voltage circuit.

Abstract: A method and arrangement for measuring output phase currents of a voltage source inverter when the inverter is connected to a load, the method comprising, during commissioning of a drive, the steps of forming consecutive voltage pulses to the load by using the inverter, measuring current of a DC bus for each consecutive pulse such that for each consecutive pulse, a time difference between a current measurement instant and a start of a voltage pulse is changed, removing a value of DC current from measured current samples to obtain sample values for stray current, storing the sample values of the stray current and their time instants with respect to the start of respective voltage pulses, the method further comprising during the use of the inverter the following steps of, measuring DC-bus current, determining an output phase current of the inverter from the measured DC-bus current and from the stored stray current samples.

Abstract: A method for determining output currents of a three-phase frequency converter comprising a voltage intermediate circuit and three power switch pairs constituting an output of the frequency converter, wherein the power switches constituting a pair are coupled in series between a positive and a negative busbar of the voltage intermediate circuit so that a midpoint of each switch pair constitutes a phase output of the frequency converter.

Abstract: The invention relates to a method and an apparatus to control a propulsion drive. The propulsion drive comprises at least one first propeller drive, which rotates the first propeller and by which the propulsion power and/or rotating speed of the first propeller, and a second propeller drive, by which the second propeller is rotated and controlled. According to the invention the propulsion drive is controlled by a single control command, whereby it is generated from the control command a first control signal, by which the first propeller drive is controlled, and a second signal, by which the second propeller drive is controlled.

Abstract: The invention relates to a configuration tool for configuring a frequency converter, which configuration tool comprises an interface for connecting the configuration tool to the frequency converter, said interface comprising means for feeding configuration data from the configuration tool to the frequency converter. To facilitate the configuration of an unelectrified frequency converter, said interface further comprises means for conveying the energy required for electrifying at least the memory of the frequency converter from the configuration tool to the frequency converter during the configuration.

Abstract: A method for determining output currents of a three-phase frequency converter comprising a voltage intermediate circuit and three power switch pairs constituting an output of the frequency converter, wherein the power switches constituting a pair are coupled in series between a positive and a negative busbar of the voltage intermediate circuit so that a midpoint of each switch pair constitutes a phase output of the frequency converter.