Abstract: A power monitoring system with associated signal processing and storage capabilities. Each leg of a three-phase power signal is simultaneously sampled on a plurality of channels to capture the instantaneous content of the power signal without time-skewing between the channels. In a further embodiment, the sampled data is converted into the frequency domain and parameters relating to the power quality of the power signal is derived from frequency-domain data.

Abstract: A power monitoring system with associated signal processing and storage capabilities. An input signal is sampled and the samples are compared to a threshold to identify an impulse. The system analyzes the length of each impulse to dynamically adapt a memory storage size to store a number of samples occurring during an impulse period. In a further embodiment, the input signal must remain below a second threshold for a fixed number of samples before storing of the samples is terminated.

Abstract: A power monitoring system with associated signal processing and storage capabilities. An input signal is sampled and the samples are used to derive total harmonic distortion, total power, and reactive power. Parameters of the input signal at a selected time are displayed as a vector superimposed on a three-axis graph having total power as one axis, reactive power as the second axis, and total harmonic distortion as the third axis.

Abstract: A power monitoring system with associated signal processing and storage capabilities. Historical data for an electrical signal is retained and displayed by dividing the electrical signal in the time domain into segments herein referred to as events. A detected disturbance of the electrical signal forms a boundary between two events. For each such boundary, the steady-state value of a signal parameter such as root-mean-square (rms) voltage is stored for the two events delimited by the boundary. Samples of the electrical signal immediately surrounding the boundary are stored so that disturbances of interest can be closely inspected.

Abstract: A power monitoring system with associated signal processing and storage capabilities. Disturbances on an electrical signal are evaluated based upon a quality factor and the disturbance and associated quality factor are stored. Disturbances with the lowest quality factor are deleted from storage when the storage device becomes full.

Abstract: A power monitoring system with associated signal processing and storage capabilities. Impulses that are superimposed on an alternating-current electrical signal are identified and evaluated based upon amplitude, duration, and phase position. Impulses that are not substantially similar to impulses on immediately preceding cycles of the input signal are recorded. In a further embodiment, if a series of substantially identical impulses occurs, a count of the number of impulses is stored, and detailed data is stored for only the first impulse in the series. In another embodiment, the impulses are ranked according to a quality factor, and data for the impulse with the lowest quality factor is deleted from a storage device when the device becomes full.

Abstract: A power monitoring instrument evaluates and displays the source impedance, load impedance, and distribution system impedance of an alternating current power system using voltage and current measurements taken at a source and load of the power system. The power monitoring instrument and associated voltage and current pods for coupling to voltage probes and current clamps incorporate unique safety features to minimize operator exposure to high-voltage. The measurements are performed noninvasively without disconnecting elements of the power system. Evaluation of impedances takes advantage of incidental variations in the load characteristics.

Abstract: A power monitoring instrument evaluates and displays the source impedance, load impedance, and distribution system impedance of an alternating current power system using voltage and current measurements taken at a source and load of the power system. The power monitoring instrument and associated voltage and current pods for coupling to voltage probes and current clamps incorporate unique safety features to minimize operator exposure to high-voltage. The measurements are performed noninvasively without disconnecting elements of the power system. Evaluation of impedances takes advantage of incidental variations in the load characteristics.

Abstract: A power monitoring instrument evaluates and displays the source impedance, load impedance, and distribution system impedance of an alternating current power system using voltage and current measurements taken at a source and load of the power system. The power monitoring instrument and associated voltage and current pods for coupling to voltage probes and current clamps incorporate unique safety features to minimize operator exposure to high-voltage. The measurements are performed noninvasively without disconnecting elements of the power system. Evaluation of impedances takes advantage of incidental variations in the load characteristics.

Abstract: The present invention is for digital calibration of plug-in transducers and the like. The invention comprises means for digitally storing error-correcting tables in a physical location which is associated with the transducer, and a means for interpreting those tables.