Abstract: The present disclosure pertains correcting linear interpolation errors. In one embodiment, a system comprises an input configured to receive the periodic signal at a first sampling rate and an output configured to provide an interpolated representation of the periodic signal at a second sampling rate. A linear interpolation subsystem may establish a ratio between the first sampling rate and the second sampling rate to determine a slip frequency. The linear interpolation subsystem creates an interpolated representation of the periodic signal based on the ratio. The interpolated representation of the periodic signal includes a deterministic error attributable to interpolation. A linear interpolation correction subsystem may correct the deterministic error attributable to the linear interpolation subsystem and create a corrected interpolated representation. An application interface subsystem may provide the corrected interpolated representation to an application.

Abstract: The present disclosure pertains correcting linear interpolation errors. In one embodiment, a system comprises an input configured to receive the periodic signal at a first sampling rate and an output configured to provide an interpolated representation of the periodic signal at a second sampling rate. A linear interpolation subsystem may establish a ratio between the first sampling rate and the second sampling rate to determine a slip frequency. The linear interpolation subsystem creates an interpolated representation of the periodic signal based on the ratio. The interpolated representation of the periodic signal includes a deterministic error attributable to interpolation. A linear interpolation correction subsystem may correct the deterministic error attributable to the linear interpolation subsystem and create a corrected interpolated representation. An application interface subsystem may provide the corrected interpolated representation to an application.

Abstract: An RTD system includes multiple pluralities of RTDs and RTD bank assembly to which each plurality of RTDs are connected. Each RTD bank assembly includes a current source for the RTDs connected thereto, a multiplexer switching system for switching the current source successively between the RTDs, and a measurement function for measuring the voltage drop across the RTDs produced by the current source. The system includes a circuit for determining resistance of the RTD from the current applied thereto and the voltage drop there across. The system further includes a plurality of low pass filters associated, respectively, with each RTD, wherein the low pass filters are charged before the voltage measurement is made. The system includes a precharging arrangement where the low pass filter associated with the next RTD in a voltage sampling sequence is precharged, so that the delay between sampling of the voltage from the low pass filters associated with successive RTDs is significantly reduced.

Abstract: The system includes a unipolar A/D converter, which samples analog signal inputs thereto, the A/D converter being used in a protective relay for electric power systems. The unipolar A/D converter is responsive to input voltage values and current values from the power line to produce corresponding digital signals. The A/D converter has a ground pin voltage reference at least as negative as the most negative point of the input signal to be processed.

Abstract: The system includes a unipolar A/D converter, which samples analog signal inputs thereto, the A/D converter being used in a protective relay for electric power systems. The unipolar A/D converter is responsive to input voltage values and current values from the power line to produce corresponding digital signals. The A/D converter has a ground pin voltage reference at least as negative as the most negative point of the input signal to be processed.