The present disclosure relates to methods and devices for calculating winding currents at a delta side for a transformer. The transformer has two or more windings, with a first winding being a delta connected winding. The method may comprise obtaining line currents measured with measurement equipment associated with lines connected with the windings. The method may further comprise calculating zero sequence currents for at least a second winding, from the line currents of a corresponding line. The method may further comprise calculating zero sequence currents for the first winding, based on the zero sequence currents for at least the second winding, a phase displacement between the windings, and a turns ratio associated with the windings. The winding currents may be calculated from the zero sequence currents of the first winding, and the line currents of a corresponding line.

A diagnostic device for diagnosing a faulty condition in a gradient amplifier system is presented. The diagnostic device includes a first current sensor configured to be coupled to an input terminal of a filter unit, where the first current sensor is configured to measure a first electric current at the input terminal of the filter unit, and where the first electric current includes a high frequency current component and a low frequency current component. Further, the diagnostic device includes a diagnostic unit coupled to the first current sensor and configured to determine an impedance across the filter unit and a load unit based on the low frequency current component of the measured first electric current and a pre-stored reference voltage, and diagnose the faulty condition of at least one component in at least one of the filter unit and the load unit based on a characteristic of the determined impedance.

A solenoid assembly includes a solenoid having a coil, a current sensor configured to measure the coil current, and a controller. The controller estimates the coil current using a solenoid model, with output of the solenoid model being an estimated coil current, and receives the measured coil current from the current sensor. The controller also calculates an error value having an error sign by subtracting the estimated coil current from the measured coil current. Responsive to the error value exceeding a calibrated error threshold while the control voltage deviates from a nominal value, the controller diagnoses a solenoid fault condition. Responsive to diagnosing the solenoid fault condition, the controller isolates or identifies a particular solenoid fault condition from among a plurality of possible fault conditions, and records a diagnostic code indicative of the particular solenoid fault condition.

The invention relates to a method (3) for determining (33) a state characteristic value (28) of a electric device (4) controlled by a temporally variable control signal (17). The at least one state characteristic value (28) is determined using the frequency of the temporally variable control signal (17) and/or the switching characteristics of the temporally variable control signal (17).

A circuit state sensing device (100) includes a transformer (102) having a primary coil (104A) and a secondary coil (104B). In use, the secondary coil is connected to a target circuit (106) for which a state is to be sensed. The device further includes a measuring arrangement (112, 122) configured to take a measurement relating to impedance at the primary coil, and a processing arrangement (122) configured to process the impedance measurement to determine a state of the target circuit.

Provided is an apparatus for determining an abnormal status of a wireless power transmission coil, the apparatus including an input-current sensor configured to detect an input current and provided at an input side of a power transmission coil, an output-current sensor configured to detect an output current and provided at an output side of the transmission coil, and a controller configured to compare each of the input current and the output current with a predetermined threshold value corresponding thereto to determine whether a disconnection or a short circuit occurs in the transmission coil.

An apparatus and method of detecting movement of a plunger of the solenoid includes detecting a peak (I.sub.PEAK) in a current signal applied to a coil of the solenoid. A predetermined threshold is added to the current signal applied to the coil of the solenoid to generate a level shifted signal. The level shifted signal and the peak signal are compared to detect movement of a plunger of the solenoid.

A method of detecting a fault in a sinusoidally controlled permanent magnet synchronous motor (PMSM). The method includes receiving a first rotor reference frame current demand, the first rotor reference frame current demand based on a current control for the PMSM and receiving a first rotor reference frame current feedback, the first rotor reference frame current feedback corresponding to the first rotor reference frame current demand received. The method also includes computing a first error of the rotor reference frame current based on the first rotor reference frame current demand and the first rotor reference frame current feedback and identifying a fault of the sinusoidally controlled PMSM if the first error exceeds a first selected threshold for a first selected duration.

Embodiments herein relate to a sensor fault measurement system. The system includes a sensor having a primary winding, a first secondary winding and a second secondary winding and a wiring harness operably connected to the primary winding, first secondary winding and second secondary winding of the sensor. The system also includes a controller operably connected to the wiring harness. The controller includes a bias network configured to apply a common mode DC voltage bias of opposite sign to the first sensor output and the second sensor output respectively, and a fault sense circuit configured to monitor the DC voltage bias on first sensor output and the DC voltage bias on second sensor output, and identify a sensor fault if at least one of the DC voltage bias on first sensor output and the DC voltage bias second sensor output is impacted beyond a selected threshold.

An apparatus for checking an inductor includes a detector outputting a detection signal including information corresponding to a parallel resistance component of a checking target inductor; and a determiner receiving the detection signal and determining whether the checking target inductor is satisfactory based on a magnitude of the parallel resistance component.