Abstract: A method of extending the lifetime of a rolling-element bearing of an electrical machine, the method including: a) defining a first set of control parameter values, b) estimating a first remaining useful life, RUL, of the rolling-element bearing, based on a signal that provides a measure of vibrations of the rolling-element bearing obtained when the electrical machine is controlled by the first set of control parameter values, c) changing at least one control parameter value in the first set of control parameter values to thereby obtain a second set of control parameter values, d) estimating a second RUL of the rolling-element bearing based on the signal, obtained when the electrical machine is controlled by the second set of control parameter values, e) comparing the first RUL with the second RUL, f) in case the second RUL is longer than the first RUL, replacing the control parameter values in the first set of control parameter values with those of the second set of control parameter values, and replacing th

Abstract: A method for estimating at least one leakage inductance of a 3n-phase electrical machine includes performing a first machine investigation scheme and a second machine investigation scheme, the first scheme including ordering a machine drive stage to control one of the 3-phase windings, obtaining a first set of measured currents from the 3-phase winding and processing the first set of measured currents to obtain primary characteristics of an electrical quantity of the electrical machine, the second scheme including ordering the machine drive stage to control all the 3-phase windings using a VSD control model, the controlling involving only controlling a first fundamental subspace of the VSD control model, obtaining a second set of measured currents from all 3-phase windings and processing the second set of measured currents to obtain a leakage inductance estimate and secondary characteristics of the electrical quantity, for which leakage inductance estimate the primary and secondary characteristics match.

Abstract: A field of electric drive devices and electric machines, such as electric motors and electric generators for industrial applications and more particularly to a method and an arrangement for controlling vibration of a variable frequency drive controlled electric machine. In the method for controlling vibration of a variable frequency drive controlled electric machine, the resonance frequency/frequencies and the stiffness are determined in a ramp up/ramp down test; amount of damping is determined in an impulse test; a mechanical transfer function is determined in a steady drive test; a vibration control model is determined utilizing said resonance frequency/frequencies, said stiffness, the amount of damping and the mechanical transfer function; and vibration is controlled utilizing the vibration control model.

Abstract: A method of extending the lifetime of a rolling-element bearing of an electrical machine, the method including: a) defining a first set of control parameter values, b) estimating a first remaining useful life, RUL, of the rolling-element bearing, based on a signal that provides a measure of vibrations of the rolling-element bearing obtained when the electrical machine is controlled by the first set of control parameter values, c) changing at least one control parameter value in the first set of control parameter values to thereby obtain a second set of control parameter values, d) estimating a second RUL of the rolling-element bearing based on the signal, obtained when the electrical machine is controlled by the second set of control parameter values, e) comparing the first RUL with the second RUL, f) in case the second RUL is longer than the first RUL, replacing the control parameter values in the first set of control parameter values with those of the second set of control parameter values, and replacing th

Abstract: A method for estimating at least one leakage inductance of a 3n-phase electrical machine includes performing a first machine investigation scheme and a second machine investigation scheme, the first scheme including ordering a machine drive stage to control one of the 3-phase windings, obtaining a first set of measured currents from the 3-phase winding and processing the first set of measured currents to obtain primary characteristics of an electrical quantity of the electrical machine, the second scheme including ordering the machine drive stage to control all the 3-phase windings using a VSD control model, the controlling involving only controlling a first fundamental subspace of the VSD control model, obtaining a second set of measured currents from all 3-phase windings and processing the second set of measured currents to obtain a leakage inductance estimate and secondary characteristics of the electrical quantity, for which leakage inductance estimate the primary and secondary characteristics match.

Abstract: A field of electric drive devices and electric machines, such as electric motors and electric generators for industrial applications and more particularly to a method and an arrangement for controlling vibration of a variable frequency drive controlled electric machine. In the method for controlling vibration of a variable frequency drive controlled electric machine, the resonance frequency/frequencies and the stiffness are determined in a ramp up/ramp down test; amount of damping is determined in an impulse test; a mechanical transfer function is determined in a steady drive test; a vibration control model is determined utilizing said resonance frequency/frequencies, said stiffness, the amount of damping and the mechanical transfer function; and vibration is controlled utilizing the vibration control model.