Abstract: A method for detecting turn-to turn faults in a laminate stack of a stator of an electrical machine or a generator includes magnetizing the stator using an auxiliary coil and an auxiliary current so as to form a magnetic field. The magnetic field is measured using a pickup device including at least two detectors disposed in at least two respective different radial positions with respect to a rotor axis so as to provide at least two signals corresponding to the magnetic field at the respective radial positions. The method includes evaluating and comparing a magnitude and/or a phase angle of the signals so as to determine a relative magnitude and/or relative phase angle by subtraction in order to detect turn-to-turn faults. Relative differences in the at least two signals are recorded. Also a device for performing the method.

Abstract: A method for monitoring a controller for controlling and/or monitoring a three-phase electric motor, in particular an asynchronous or synchronous motor, wherein two phase currents are measured and an error signal is generated if at least one of the two measured phase currents is essentially zero. An error signal is also generated if none of the two measured phase currents is essentially zero, but a sum formed of the two measured phase currents is essentially zero.

Abstract: An inspection vehicle (24) for inspecting an air gap (14) between the rotor (11) and the stator (12) of a generator (10) includes drive elements (25, 27) for the independent progressive movement in the air gap (14). A particularly compact construction and flexible application is achieved by the drive elements (26, 27) being formed as elongated, flexionally elastic, torsionally rigid, magnetic rolls.

Abstract: A method for evaluating a permanent magnet motor, which includes a rotor with a plurality of magnets mounted thereon, and a stator with a plurality of windings in proximity to the rotor and coupled to an inverter, includes spinning the motor such that a voltage is induced in the windings of the stator and the inverter; measuring the voltage on the inverter; calculating the voltage constant from the motor from the measured voltage; comparing the voltage constant to accepted voltage constants; and identifying the motor as not acceptable if the voltage constant is outside of a range of the accepted voltage constants.

Abstract: A system and method for determining electric motor efficiency includes a monitoring system having a processor programmed to determine efficiency of an electric motor under load while the electric motor is online. The determination of motor efficiency is independent of a rotor speed measurement. Further, the efficiency is based on a determination of stator winding resistance, an input voltage, and an input current. The determination of the stator winding resistance occurs while the electric motor under load is online.

Abstract: Single networkable fault monitoring system for monitoring electrical parameters on at least one electrical phase on at least one interconnected electric chain hoist for various fault conditions. When at least one fault signal is generated, at least one kill signal is generated in the fault monitoring system, causing generation of at least one kill function in at least one chain hoist motor controller. The generated kill function causes a power disconnection to all connected electric chain hoists and/or the entire network of fault monitoring systems. When a fault has been generated, each individual fault signal outputs fault specific diagnostic data from the fault monitoring system to help an operator identify the fault specific electric chain hoist(s) and the specific fault type(s). This data is intended for the purpose of interfacing with an operator monitoring device, LED indicators, data logger, and/or any other user-defined application or combination thereof.

Abstract: A method of estimating stator resistance of an induction motor is provided. The method includes applying voltage pulses through two phase paths of the motor for a plurality of electrical cycles to inject current in the motor, wherein the voltage pulses are applied until rotor flux of the motor is substantially stabilized and measuring stator voltage and stator current in response to the applied voltage pulses for each of the plurality of electrical cycles. The method also includes calculating the stator resistance based upon the measured stator voltages and the stator currents.

Abstract: The control system of the invention includes at least one actuator (6) for a cowling (2), driven by at least one electric motor (7), and control means (9) for the electric motor (7) and the actuator (6). The control system includes an electric circuit (C) that comprises: a plurality of electric components; a plurality of measuring means (16-18) adapted for measuring respectively a characteristic magnitude of an electric component or a group of electric components in the electric circuit; a failure detection means (19) adapted for detecting a failure at a component of the electric circuit when the characteristic magnitude measured at said component exceeds a predetermined value or is in a range of predetermined values.

Abstract: The invention specifies a method for fault identification when driving a polyphase motor by means of a frequency converter, wherein, in a rest state, the frequency converter controls the phase voltages of the polyphase motor and the phase currents of the polyphase motor are measured. In this case, provision is made for, then in the rest state, the phase currents or current variables derived therefrom to be adjusted by closed-loop control to a predetermined setpoint current variable, for the frequency converter to be controlled so as to output an interference voltage variable for the phase voltages, for the response of the adjustment by closed-loop control to the interference voltage variable to be observed, and for a conclusion to be drawn regarding a fault of the frequency converter and/or the phases of the polyphase motor from the response of the closed-loop control. The cited method allows for largely loss-free detection of faults in the drive system of a polyphase motor.

Abstract: A system and method is provided for ground testing of a yaw system of a nacelle (3) prior to erection of a wind turbine (1). A portable transformer box (10) is provided which will allow the nacelle preparation team to operate the yaw and hydraulic systems while the nacelle is grounded prior to erection.

Abstract: Various methods and systems for testing electric automotive drive systems are provided. The methods may be implemented with components with components that are used during normal operation of the automobile, such an inverter, an electric motor, and an electronic control system. One such method includes adjusting the frequency of a current pulsed input provided to an electric motor while monitoring the winding currents. Another method includes monitoring current flow during and after a direct current (DC) pulse is generated by switches within an inverter. A further method includes monitoring current flow while a deactivation signal is provided to the switches and during individual activation of the switches.

Abstract: The invention concerns a method for detecting a fault in a rotating field machine, in which current components are analysed in a flux-based, particularly rotor-flux-based, coordinate system a flux-forming current component being subjected to a frequency analysis in the flux-based, particularly rotor-flux-based, coordinate system. It is endeavoured to provide a simple method for an early detection of faults. For this purpose, a current operating point is detected for at least one predetermined supply frequency (fsp), said operating point being compared to a former operating point.

Abstract: A method and an apparatus are described for detection of interlaminar laminate shorts in the laminated stator core of electrical machines, in which the laminated stator core (4) is subjected to an externally applied field current (2) or field voltage (V), and the short-circuit magnetic field (Bshort) induced by short-circuit currents (5) is measured with the assistance of a sensor coil (S1) which is arranged in the gap in the machine and probes this gap. Improved identification of laminate shorts, in particular even of small laminate shorts with small short-circuit currents, is possible in that a field current (2) and a field voltage (V) are applied which have a waveform which differs significantly from a sinusoidal shape, in particular with a periodic character, and have significant harmonic components in the high frequency range. By way of example, a waveform in the form of a square-wave curve is proposed.

Abstract: A method and an arrangement are provided for identifying parameters of an induction machine when the induction machine is connected to the output phases of a voltage source inverter and the induction machine is in standstill state. The method includes providing a DC magnetization current (idc—magn) to the induction machine with the inverter, controlling the power semiconductors of the inverter to an off-state, controlling all the output phases of the inverter to the same potential to provide a zero voltage vector, measuring the stator current (isd) during the zero voltage vector, and determining parameters of the induction machine from the stator current (isd) measured during the zero voltage vector.

Abstract: A current transformer is provided. The current transformer comprises a magnetic core having a central opening, at least one pair of conductors extending through the central opening and positioned symmetrically with respect to a center point of the magnetic core, one or more coils disposed on the magnetic core along a magnetic neutral axis of the magnetic core and one or more coils disposed on the magnetic core along a reference axis, wherein the reference axis is substantially perpendicular to the magnetic neutral axis.

Abstract: A method is specified for fault identification when operating a rotating-field motor by means of a pulse-controlled inverter, wherein electromagnetic state variables of the rotating-field motor are determined by means of a mathematical model in space-vector form, and wherein the pulse-controlled inverter is operated electronically using space-vector variables. In this case, the invention provides that, during the operation of the rotating-field motor, the space vector of an uncontrolled state variable of the rotating-field motor is formed, in that the space vector that is formed is analyzed for a spectral component at twice the frequency of the rotating field, and in that, if the spectral component at twice the frequency is present, a partial turns short is deduced in the stator windings.

Abstract: The invention relates to a device for the diagnosis of flanges in tri-phase motors. More specifically, the invention relates to a device comprising means for the inductive acquisition of currents in a common mode for the simple and practical diagnosis of the defects in the flanges of a tri-phase motor. The invention also relates to a current-measuring device comprising means for capturing currents by inductive methods. The invention further relates to a device and a method for detecting defects in alternating-current electric motors, and more specifically, to a device and a method for obtaining parameters relating to the possible defects in an electric motor, in order to carry out a reliable diagnosis of the defects during the normal operation of the motor.