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: There is provided displaying a user interface during a power outage. A touchscreen comprises a lower layer comprising an electronic paper display and an upper layer comprising a transparent display. The touch screen may be arranged in a frequency converter and a drive system.

Abstract: A frequency converter comprises energy transfer means capable of wireless inductive power transfer to a wireless terminal device placed to an inductive charging position of the frequency converter. In response to recognising that the terminal device is placed to the charging position, an identification procedure is carried out between the frequency converter and the terminal device via a wireless connection established between the frequency converter and the terminal device. If based on the identification procedure it is determined that the terminal device is an authorized terminal device, the method comprises displaying, on a display of the frequency converter, a user interface of the frequency converter, such that the frequency converter is controllable by a user by means of interactive elements displayed on the user interface.

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 method is specified for operating a rotating electrical machine (1), which machine (1) has at least two sets of stator windings (A, B), in each case one associated converter unit (2) being provided for each set of stator windings (A, B) and each set of stator windings (A, B) comprising n phase windings, where n?3, in which method the respective set of stator windings (A, B) is fed by the associated converter unit (2).

Abstract: A method is specified for operating a rotating electrical machine (1), which machine (1) has at least two sets of stator windings (A, B), in each case one associated converter unit (2) being provided for each set of stator windings (A, B) and each set of stator windings (A, B) comprising n phase windings, where n?3, in which method the respective set of stator windings (A, B) is fed by the associated converter unit (2).

Abstract: A method of defining an instantaneous value of a current (i2e) of a pulse-controlled inductive load when the impedance of the load is known, the method comprising the steps of: measuring the output voltage (u1) of a pulsed voltage source, and measuring the output current (i1) of the pulsed voltage source. The method is characterized by further comprising the steps of: low-pass filtering the measured output current (i1) of the pulsed voltage source to produce a fundamental wave current (i1lp), defining a load current estimate (i2est) by computation on the basis of the measured output voltage (u1) of the pulsed voltage source and the impedance of the load, high-pass filtering the load current estimate (i2est), and defining the instantaneous value of the load current (i2e) by adding the high-pass-filtered load current estimate (i2hp) to the fundamental wave current (i1p).

Abstract: The invention relates to a method of starting an asynchronous machine irrespective of whether the rotor of the machine is rotating or not when the machine is supplied by an inverter provided with a separate moment and flux or moment and magnetizing current control, which is faster than the time constants of the asynchronous machine. According to the invention, zero moment is set as a target for the control, a voltage is supplied to the stator of the machine by the inverter, a stator current vector and a stator flux generated by the voltage is determined, an estimate of that vector or some other quantity comparable to the stator flux is determined, a moment caused by the stator flux vector and the stator current vector is determined and information of the moment is supplied to the control, which tries to zero the caused moment by making the stator flux and a rotor flux generated thereby cophasal, thus synchronizing the supply frequency of the inverter with a possible rotation of the machine rotor.