There is provided a broadband lossless partial discharge detection and noise removal device which includes: a partial discharge occurrence timing pulse acquiring unit acquiring a generated timing pulse of a partial discharge signal at the beginning of generation of a partial discharge signal; a partial discharge magnitude pulse acquiring unit acquiring a magnitude pulse of the partial discharge signal; a synchronization comparing unit detecting a partial discharge digital signal determined according to whether the generated timing pulse of the partial discharge signal and the magnitude pulse are synchronized; and a partial discharge signal generating unit detecting a partial discharge pulse obtained by converting the detected partial discharge digital signal into an analog signal.

A probe calibration device that includes a first offset element having a substantially rectangular first aperture. The probe calibration device includes a tuned pass element disposed adjacent to the first offset element. The tuned pass element has a non-rectangular second aperture. The probe calibration device includes a second offset element disposed adjacent to the tuned pass element and on a side opposite the first offset element. The second offset element has a substantially rectangular third aperture. The probe calibration device includes a backing element disposed adjacent to the second offset element. The first offset element, the tuned pass element, the second offset element and the backing element form a cavity.

A probe calibration device that includes a first offset element having a substantially rectangular first aperture. The probe calibration device includes a tuned pass element disposed adjacent to the first offset element. The tuned pass element has a non-rectangular second aperture. The probe calibration device includes a second offset element disposed adjacent to the tuned pass element and on a side opposite the first offset element. The second offset element has a substantially rectangular third aperture. The probe calibration device includes a backing element disposed adjacent to the second offset element. The first offset element, the tuned pass element, the second offset element and the backing element form a cavity.

A method for correcting a time-dependent measurement signal generated by means of an electric motor coupled on the output side to a transmission with regard to the influence of a variable output load and a variable rotational speed includes: tapping a time-varying measurement signal which is dependent on a torque of the motor transmission unit; generation of a useful signal, which is free of any DC component, from the measurement signal; interval-by-interval determination of RMS values from the measurement signal; generation of a load-corrected useful signal by an interval-by-interval division of the useful signal, which is free of any DC component, by the interval-specific RMS values; time-resolved determination of the rotational frequency of the motor from the measurement signal; scaling the load-corrected useful signal to the mean rotational frequency to generate a corrected measurement signal, and, use of the corrected measurement signal for fault detection of the motor transmission unit.

A method for correcting a time-dependent measurement signal generated by means of an electric motor coupled on the output side to a transmission with regard to the influence of a variable output load and a variable rotational speed includes: tapping a time-varying measurement signal which is dependent on a torque of the motor transmission unit; generation of a useful signal, which is free of any DC component, from the measurement signal; interval-by-interval determination of RMS values from the measurement signal; generation of a load-corrected useful signal by an interval-by-interval division of the useful signal, which is free of any DC component, by the interval-specific RMS values; time-resolved determination of the rotational frequency of the motor from the measurement signal; scaling the load-corrected useful signal to the mean rotational frequency to generate a corrected measurement signal, and, use of the corrected measurement signal for fault detection of the motor transmission unit.

Embodiments are described of devices and methods for processing a signal using a plurality of vector signal generators (VSGs). A digital signal may be provided to a plurality of signal paths, each of which may process a respective frequency band of the signal, the respective frequency bands having regions of overlap. The gain and phase of each signal path may be adjusted such that continuity of phase and magnitude are preserved through the regions of overlap. The adjustment of gain and phase may be accomplished by a complex multiply with a complex calibration constant. The calibration constant may be determined for each signal path by comparing the gain and phase of one or more calibration tones generated within each region of overlap. Each signal path may comprise a VSG to convert the respective signal to an analog signal, which may be combined to obtain a composite signal.

A frequency discriminator is described. The frequency discriminator comprises a power splitter (2) for splitting a signal into a plurality of paths (4.sub.0, 4.sub.1, 4.sub.2, . . . , 4.sub.n). At least two of the plurality of paths (4.sub.1, 4.sub.2, . . . , 4.sub.n) include respective filters (12.sub.1; 12.sub.2, . . . , 12.sub.n) having different frequency characteristics which are configured to provide respective filtered signals to respective power detectors (16.sub.1, 16.sub.2, . . . , 16.sub.n. The frequency discriminator comprises an analogue-to-digital conversion section (8) which is configured to receive values of measured powers from the power detectors, to generate digital values of measured powers and to provide the digital values of measured powers to a digital processing section (10). The digital processing section is configured to estimate a value (11) of at least one frequency in the signal in dependence on the digital values, for example the ratio of the digital values, of measured powers and on frequency responses (20.sub.1, 20.sub.2, . . . , 20.sub.n; FIG. 2) of the filters.

A frequency discriminator is described. The frequency discriminator comprises a power splitter (2) for splitting a signal into a plurality of paths (4.sub.0, 4.sub.1, 4.sub.2, . . . , 4.sub.n). At least two of the plurality of paths (4.sub.1, 4.sub.2, . . . , 4.sub.n) include respective filters (12.sub.1; 12.sub.2, . . . , 12.sub.n) having different frequency characteristics which are configured to provide respective filtered signals to respective power detectors (16.sub.1, 16.sub.2, . . . , 16.sub.n. The frequency discriminator comprises an analogue-to-digital conversion section (8) which is configured to receive values of measured powers from the power detectors, to generate digital values of measured powers and to provide the digital values of measured powers to a digital processing section (10). The digital processing section is configured to estimate a value (11) of at least one frequency in the signal in dependence on the digital values, for example the ratio of the digital values, of measured powers and on frequency responses (20.sub.1, 20.sub.2, . . . , 20.sub.n; FIG. 2) of the filters.

In one aspect, an apparatus includes: a mixer to receive a radio frequency (RF) signal and downconvert the RF signal into a second frequency signal; an amplifier coupled to the mixer to amplify the second frequency signal; an image rejection (IR) circuit coupled to the programmable gain amplifier (PGA) to orthogonally correct a gain and a phase of the amplified second frequency signal to output a corrected amplified second frequency signal; and a complex filter to filter the corrected amplified second frequency signal.

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.