Abstract: An electromechanical device comprises a stator and a rotor which is capable of rotating relative to the stator. The rotor has a sensor embedded therein. In a preferred embodiment, the sensor is disposed within a plurality of laminations that are stacked one on top of another. For example, one of the plurality of laminations may be a sensor lamination, in which case the sensor is at least partially disposed within a cavity formed in the sensor lamination. Advantageously, the sensor may be used to directly measure rotor-associated operating conditions, such as rotor current (including the magnitude, frequency and phase of the rotor current), rotor fatigue, rotor temperature, rotor airgap, rotor flux and rotor torque. The sensor is especially well-suited for measuring current in the rotor of an induction motor.

Abstract: An electromechanical device comprises a stator and a rotor which is capable of rotating relative to the stator. The rotor has a sensor embedded therein. In a preferred embodiment, the sensor is disposed within a plurality of laminations that are stacked one on top of another. For example, one of the plurality of laminations may be a sensor lamination, in which case the sensor is at least partially disposed within a cavity formed in the sensor lamination. Advantageously, the sensor may be used to directly measure rotor-associated operating conditions, such as rotor current (including the magnitude, frequency and phase of the rotor current), rotor fatigue, rotor temperature, rotor airgap, rotor flux and rotor torque. The sensor is especially well-suited for measuring current in the rotor of an induction motor.

Abstract: An electromechanical device comprises a stator and a rotor which is capable of rotating relative to the stator. The rotor has a sensor embedded therein. In a preferred embodiment, the sensor is disposed within a plurality of laminations that are stacked one on top of another. For example, one of the plurality of laminations may be a sensor lamination, in which case the sensor is at least partially disposed within a cavity formed in the sensor lamination. Advantageously, the sensor may be used to directly measure rotor-associated operating conditions, such as rotor current (including the magnitude, frequency and phase of the rotor current), rotor fatigue, rotor temperature, rotor airgap, rotor flux and rotor torque. The sensor is especially well-suited for measuring current in the rotor of an induction motor.

Abstract: A test procedure detects the onset of stator winding damage, identifies the failure mechanism, determines the winding's susceptibility to further damage, and predicts stator winding failure. This is accomplished by introducing a high frequency signal onto power lines which feed the stator and monitoring a change in the capacitance between the individual windings during introduction of the high frequency signal. In order to monitor the change in capacitance, a current sensor and voltage sensor are used to measure the current and voltage on the power lines during introduction of the high frequency signal. Changes in the capacitance between the individual stator windings are reflected as changes in the broadband impedance response of the stator windings which can be calculated by dividing the measured voltage by the measured current.

Abstract: A method and apparatus for real-time electric motor diagnostics and condition monitoring. While the motor is energized, dynamic operating parameters are determined and a notification signed is generated if predetermined criterion are satisfied. The diagnostic apparatus is integrated with the motor and includes a set of sensors, a processing unit, a memory and an output interface for communicating alarms, warnings and calculated operating parameter values or the like to a display device and to an external supervisor having wireless paging capability to alert a remote operator or maintenance personnel. In a normal operating mode, the processing unit calculates a general class of derived motor operating parameters such as over-temperature, over-voltage, over-current, excessive vibration, and phase imbalance.

Abstract: A magnetic top stick for use at the opening portion of a core slot of an electromagnetic device includes a group of magnetically anisotropic members arranged in a substantially non-magnetic body adapted to fit snugly within the core slot. The magnetic properties of the group of members combine to provide the top stick with an overall high magnetic permeability in the depth direction of the core slot and overall low magnetic permeabilities in the width and longitudinal directions of the core slot. A convenient method of manufacturing the top stick includes first forming magnetically anisotropic sheets by cold rolling and annealing, then laminating and heat processing the sheets with B stage materials to generate a unitary laminated structure. The unitary laminated structure is sectioned into multiple magnetic flux bars which are in turn disposed in the non-magnetic body forming the top stick.