Abstract: The present invention relates to a drive for an electric application such as an electric motor, said drive including at least one microphone for registering noise signals occurring at the drive, wherein the microphone is connectable to a computing device for analysing the registered noise signals. The registered noise signals may be used for a maintenance process of the drive and/or a fine-tuning process of a drive control method of the drive. The present invention also relates to a maintenance process, in particular a predictive maintenance process for a corresponding drive. Furthermore, the present invention relates to a process for fine tuning a drive control method of a corresponding drive.

Abstract: The present invention relates to a drive for an electric application such as an electric motor, said drive including at least one microphone for registering noise signals occurring at the drive, wherein the microphone is connectable to a computing device for analysing the registered noise signals. The registered noise signals may be used for a maintenance process of the drive and/or a fine-tuning process of a drive control method of the drive. The present invention also relates to a maintenance process, in particular a predictive maintenance process for a corresponding drive. Furthermore, the present invention relates to a process for fine tuning a drive control method of a corresponding drive.

Abstract: A method and arrangement for controlling semiconductor power switches, e.g. IGBTs, in parallel connected power devices, e.g. in frequency converters, wherein the semiconductor power switches connect either the positive or the negative pole of the intermediate DC-voltage of the power device to an output phase of the power device. In the method the voltages of those output phases which are connected in parallel are measured, the timing differences of the output voltage state changes are calculated on the basis of the output voltage measurement results, and the control signals of the semiconductor power switches are advanced or delayed such that the output voltage state changes in the phases which are connected together via output impedances occur at desired time instants.

Abstract: A power electronic converter comprises controllable switches (104-109) and a control system (110) for operating the controllable switches. The control system is configured to control the controllable switches so as to produce at least one test voltage pulse. The power electronic converter comprises a voltage sensor (111) for detecting a reflected voltage that is caused by a reflection of the test voltage pulse in an electric system connected to the power electronic converter. The control system is configured to control the operation of the power electronic converter at least partly in accordance with information based on the detection of the reflected voltage. The information can be used for example for determining forbidden voltage pulse lengths which would cause reflection-based over-voltages and/or for detecting faults such as short circuits and earth faults.

Abstract: A power electronic converter comprises controllable switches (104-109) and a control system (110) for operating the controllable switches. The control system is configured to control the controllable switches so as to produce at least one test voltage pulse. The power electronic converter comprises a voltage sensor (111) for detecting a reflected voltage that is caused by a reflection of the test voltage pulse in an electric system connected to the power electronic converter. The control system is configured to control the operation of the power electronic converter at least partly in accordance with information based on the detection of the reflected voltage. The information can be used for example for determining forbidden voltage pulse lengths which would cause reflection-based over-voltages and/or for detecting faults such as short circuits and earth faults.

Abstract: A method and arrangement for controlling semiconductor power switches, e.g. IGBTs, in parallel connected power devices, e.g. in frequency converters, wherein the semiconductor power switches connect either the positive or the negative pole of the intermediate DC-voltage of the power device to an output phase of the power device. In the method the voltages of those output phases which are connected in parallel are measured, the timing differences of the output voltage state changes are calculated on the basis of the output voltage measurement results, and the control signals of the semiconductor power switches are advanced or delayed such that the output voltage state changes in the phases which are connected together via output impedances occur at desired time instants.