Current sensing devices that are capable of surviving harsh ambient environment of ocean worlds, such as Jupiter and Saturn moons are disclosed. The described devices can meet 300 Krad radiation requirements and can survive at cold temperatures down to −184° C. Exemplary implementations of the constituent circuits of the devices are presented. A scheduling algorithm to perform various measurement by the disclosed current sensing devices is also described.

An apparatus that detects a rotor input is provided. The apparatus includes a rotor comprising at least a portion which is configured to rotate around an axis of rotation; a reactance element disposed in the rotor, a sensing medium member disposed in the rotor, and a motion conversion member configured to move in the rotor based on a rotation of the portion of the rotor, and configured to move together with the sensing medium member to change a reactance of the reactance element according to the rotation of the portion of the rotor.

A method and an apparatus are described for monitoring the wear of a long stator linear motor system comprising at least one motor train with stators and at least one transport vehicle that is driven electromagnetically thereby. Due to the fact that a force exerted electromagnetically and/or mechanically upon said motor train by the transport vehicle transverse to the latter's direction of transport or a differential force exerted in such manner by the transport vehicle upon two oppositely disposed motor trains is measured using sensors, changes in the forces between the motor train and the vehicle caused by dimensional tolerances and/or wear can be detected in order to prevent a malfunction of the track switch.

A method of monitoring an electrical machine, wherein the method includes: a) obtaining temperature measurement values of the temperature at a plurality of locations of the electrical machine, b) obtaining estimated temperatures at the plurality of locations given by a thermal model of the electrical machine, the thermal model including initial weight parameter values, c) minimizing a difference between the temperature measurement values and the estimated temperatures by finding optimal weight parameter values, d) storing the initial weight parameter values to thereby obtain a storage of used weight parameter values, and updating the optimal weight parameter values as new initial weight parameter values, and repeating steps a)-d) over and over during operation of the electrical machine.

A measuring apparatus for measuring losses in a circumferential segment for an electrical machine is provided. The measuring apparatus includes a frame to which a circumferential segment is fixable and a flux element attached to the frame so that a circumferential segment fixed to the frame and the flux element are radially distanced and that a magnetic flux generated by a current flowing along the coil windings housed in one slot of the circumferential segment follows a magnetic flux path including at least a first path portion in one tooth circumferentially adjacent to the one slot, a second path portion in the yoke, a third path portion in the other tooth circumferentially adjacent to the one slot and a fourth path portion in the flux element.

A method for monitoring insulation in a motor drive circuit configured to convert DC power from a power source to AC power to drive a motor. The method includes boosting a DC link voltage of an inverter of the motor drive, isolating the motor drive circuit from the power source; performing at least one isolation test by providing a current path through components of the motor drive and preferably a motor connected to the output of the inverter to be tested; and monitoring the current during each isolation test to detect partial discharge or excessive leakage from the current path, thereby indicating that there exists defects in the insulation in the current path.

Provided are a short circuit state analyzer to compare difference value when the AC excitation current is applied at a first frequency with a threshold value, to estimate a short circuit resistance from the difference value based on data indicating a relationship between the short circuit resistance and the difference value at the first frequency when the difference value is smaller than the threshold value, to cause an excitation power supply to apply the AC excitation current to the field windings at a second frequency lower than the first frequency when the difference value is equal to or greater than the threshold value, and to estimate the short circuit resistance from a difference value obtained by the AC excitation current at the second frequency based on data indicating a relationship between the short circuit resistance and the difference value at the second frequency.

An apparatus that detects a rotor input is provided. The apparatus includes a rotor comprising at least a portion which is configured to rotate around an axis of rotation; a reactance element disposed in the rotor, a sensing medium member disposed in the rotor, and a motion conversion member configured to move in the rotor based on a rotation of the portion of the rotor, and configured to move together with the sensing medium member to change a reactance of the reactance element according to the rotation of the portion of the rotor.

Systems and methods relate to electric propulsor fault detection. An exemplary system includes at least a first inverter configured to accept a direct current and produce an alternating current, a first propulsor, a first motor operatively connected with the first propulsor and powered by the alternating current, and at least a noise monitoring circuit electrically connected with the direct current and configured to detect electromagnetic noise and disengage the at least an inverter as a function of the electromagnetic noise.

A method of monitoring the performance of a multi-phase electric motor (13), wherein the electric motor comprises a plurality of stator windings (7, 8, 9) connected in a wye configuration to form a wye point. The method comprises measuring an electrical characteristic of the wye point in a time domain; based upon the measured electrical characteristic of the wye point in the time domain, determining an electrical characteristic of the wye point in the frequency domain; and deriving data indicative of at least one parameter of the performance of the electric motor based upon the determined electrical characteristic of the wye-point in the frequency domain.