The present disclosure relates to systems and methods for detecting a winding fault and the winding fault severity in a brushless direct current motor before motor failure. Methods for detecting a winding fault include time domain based sequence component analysis, fast Fourier transform analysis, or Hilbert analysis. Methods for detecting the severity of a winding fault include analysis of the standard deviation of real mean squared values determined using motor currents.

Embodiments of the invention include methods and devices for determining a phase angle offset between a phase angle of a local oscillator relative to a phase angle of a signal input of a Device Under Test (DUT). Some embodiments include a laser source and an optical phase adjustor, which may be embodied by a loop stretcher structured to controllably stretch a length of fiber optic cable, driven by a phase adjust driver. In other embodiments the phase angle offset information is conveyed to an oscilloscope for internal compensation.

Embodiments of the invention include methods and devices for determining a phase angle offset between a phase angle of a local oscillator relative to a phase angle of a signal input of a Device Under Test (DUT). Some embodiments include a laser source and an optical phase adjustor, which may be embodied by a loop stretcher structured to controllably stretch a length of fiber optic cable, driven by a phase adjust driver. In other embodiments the phase angle offset information is conveyed to an oscilloscope for internal compensation.

A system for determining a phase of a power supply coupled to a metering device. The system includes a collection device in electronic communication with a metering device connected to a power distribution network and having a memory and one or more electronic processors. The electronic processors are configured to receive a first beacon signal and measure a phasor in response to receiving the first beacon signal. The phasor is stored in the memory along with an identification value associated with the device that transmitted the first beacon signal and a first time. The electronic processors receive a second beacon signal, and extract data from the request message. The electronic processors determine whether the extracted time matches the first time and based on determining that the extracted time matches the first time stored in the memory, calculate a phase by comparing the reference phasor data to the stored phasor.

A system for determining a phase of a power supply coupled to a metering device. The system includes a collection device in electronic communication with a metering device connected to a power distribution network and having a memory and one or more electronic processors. The electronic processors are configured to receive a first beacon signal and measure a phasor in response to receiving the first beacon signal. The phasor is stored in the memory along with an identification value associated with the device that transmitted the first beacon signal and a first time. The electronic processors receive a second beacon signal, and extract data from the request message. The electronic processors determine whether the extracted time matches the first time and based on determining that the extracted time matches the first time stored in the memory, calculate a phase by comparing the reference phasor data to the stored phasor.

A method of characterizing an envelope tracking amplification stage, the method comprising: generating an input test waveform which is representative of an input waveform under normal operating conditions of the amplification stage; applying a respective one of a plurality of different shaping functions, each comprising a non-linear transfer function, to the input signal envelope in each of a plurality of test periods during the period in which the input test waveform is applied as the input signal to generate the input to the envelope tracking modulated supply voltage; measuring parameters of the amplification stage during the period in which the input test waveform is applied in order to allow determination of the gain, phase and efficiency characteristics of the amplifier; and for each of the gain, phase and efficiency characteristics, generating a three dimensional plot of the characteristic with respect to input power and supply voltage applied to the amplifier.

A method of characterizing an envelope tracking amplification stage, the method comprising: generating an input test waveform which is representative of an input waveform under normal operating conditions of the amplification stage; applying a respective one of a plurality of different shaping functions, each comprising a non-linear transfer function, to the input signal envelope in each of a plurality of test periods during the period in which the input test waveform is applied as the input signal to generate the input to the envelope tracking modulated supply voltage; measuring parameters of the amplification stage during the period in which the input test waveform is applied in order to allow determination of the gain, phase and efficiency characteristics of the amplifier; and for each of the gain, phase and efficiency characteristics, generating a three dimensional plot of the characteristic with respect to input power and supply voltage applied to the amplifier.

Determination of electrical network topology and connectivity are described herein. A zero-crossing is indicated at a time when the line voltage of a conducting wire in an electrical grid is zero. Such zero-crossings may be used to measure time within a smart grid, and to determine the connectivity of, and the electrical phase used by, particular network elements. A first meter may receive a phase angle determination (PAD) message, including zero-crossing information, sent from a second meter, hereafter called a reference meter. The first meter may compare the received zero-crossing information to its own zero-crossing information. A phase difference may be determined between the first meter and the reference meter from which the PAD message originated. The first meter may pass the PAD message to additional meters, which propagate the message through the network. Accordingly, an electrical phase used by meters within the network may be determined.

Determination of electrical network topology and connectivity are described herein. A zero-crossing is indicated at a time when the line voltage of a conducting wire in an electrical grid is zero. Such zero-crossings may be used to measure time within a smart grid, and to determine the connectivity of, and the electrical phase used by, particular network elements. A first meter may receive a phase angle determination (PAD) message, including zero-crossing information, sent from a second meter, hereafter called a reference meter. The first meter may compare the received zero-crossing information to its own zero-crossing information. A phase difference may be determined between the first meter and the reference meter from which the PAD message originated. The first meter may pass the PAD message to additional meters, which propagate the message through the network. Accordingly, an electrical phase used by meters within the network may be determined.

A method of obtaining characteristic measurements K and α of an electrical system comprising at least two terminals, the method comprising: injecting a reference voltage at a first of the at least two terminals; measuring a voltage at a second of the at least two terminals to provide a measured voltage, the second terminal being connected to earth; measuring a ratio of amplitude between the injected reference voltage and the measured voltage to provide a K value; and measuring a phase angle difference between the injected reference voltage and the measured voltage to provide an angle value α.