A system and method for phase and gain calibration of a current sensor system. The system comprises a microcontroller configured to execute software in an energy measurement component and a calibration computer having a calibration application. The energy measurement component receives first and second digital signals representing current and voltage signals, respectively, received from a test source, and calculates active power and a power factor, and provides those values to the calibration computer. The power factor is converted to a converted phase angle. Based on the information received from the energy measurement component, the calibration application calculates parameters used to update components within the microcontroller to maximize the accuracy of the current sensor system.

Methods, systems, and apparatus, including computer programs stored on a computer-readable storage medium, for obtaining, from an electric field sensor, measurements of a net electric field resulting from a combination of respective electric fields from two or more electrical power conductors that are proximate to the electric field sensor. The apparatus detects a change in successive measurements of the net electric field. The apparatus determines, based on the change, that an electrical fault has occurred in one of the two or more electric power conductors. The apparatus sends to a server system, data indicating that the electrical fault has occurred in one of the two or more electric power conductors.

A circuit for sensing a current comprises a substrate having a first and a second major surface, the second major surface being opposite to the first major surface. At least one magnetic field sensing element is arranged on the first major surface of the substrate and is suitable for sensing a magnetic field caused by a current flow in a current conductor coupled to the second major surface. The substrate also comprises at least one insulation layer, substantially buried between the first major surface and the second major surface of the substrate.

A data processing board according to an embodiment of the present disclosure includes a data processing module including at least one data processing board for automatically assigning an identifier according to the voltage value measured in the internal circuit and a communication board for transmitting and receiving signal to/from the data processing board, and a data processing system including the data processing module and a monitor collecting device for selecting and parallel-processing the data received from the data processing module.

A current sensor for a detection target current using a shunt resistor includes: a resistance value correction circuit having a correction resistor; a signal application unit that applies an alternating current signal to a series circuit of the shunt resistor and the correction resistor; a voltage detection unit that detects terminal voltages of the shunt resistor and the correction resistor; and a correction unit that calculates a resistance value of the shunt resistor and corrects the resistance value for detection; and a power supply circuit having a first power supply generation unit that generates a first power supply of the signal application unit from an input power supply of an outside; and a second power supply generation unit that generates a second power supply of the voltage detection unit.

A current sensor for detecting a current based on a terminal voltage and a resistance value of a shunt resistor, includes: a resistance value correction circuit having: correction resistors; a signal application unit; a voltage detection unit that detects terminal voltages of the shunt resistor and a part of the correction resistors in a first period, and terminal voltages of all of the correction resistors in a second period; and a correction unit that corrects the resistance value for current detection based on a calculated resistance value of the shunt resistor. Resistance values and resistance accuracies of the correction resistors are higher as the plurality of correction resistors are disposed farther from the shunt resistor.

A current sensor of a detection target current using a shunt resistor includes: a resistance value correction circuit having: a correction resistor; a signal application unit that applies an alternating current signal to a series circuit of the shunt resistor and the correction resistor; a first voltage detection unit that detects the terminal voltage of the shunt resistor; a second voltage detection unit that detects a terminal voltage of the correction resistor; and a correction unit that calculates the resistance value of the shunt resistor based on a first voltage detection value by the first voltage detection unit and a second voltage detection value by the second voltage detection unit, and corrects the resistance value for current detection based on a calculated resistance value of the shunt resistor.

A power quality analysis system is configured to carry out a power quality analysis in an electrical environment. The system comprises one or more power consuming units each electrically connected to a main power supply by a multiconductor (multicore) cable and one or more power quality sensors configured to provide one or more power quality analysis measurements. The one or more power quality sensors are clamp-on power quality sensors configured to provide one or more power quality analysis measurements when the clamp-on power quality sensors are clamped onto the outside of or arranged in the proximity of the multiconductor cable. The clamp-on power quality sensors are configured to provide the one or more power quality analysis measurements without being electrically connected to any of the conductors of the multiconductor cable.

A power quality analysis system is configured to carry out a power quality analysis in an electrical environment. The system comprises one or more power consuming units each electrically connected to a main power supply by a multiconductor (multicore) cable and one or more power quality sensors configured to provide one or more power quality analysis measurements. The one or more power quality sensors are clamp-on power quality sensors configured to provide one or more power quality analysis measurements when the clamp-on power quality sensors are clamped onto the outside of or arranged in the proximity of the multiconductor cable. The clamp-on power quality sensors are configured to provide the one or more power quality analysis measurements without being electrically connected to any of the conductors of the multiconductor cable.

In accordance with an embodiment, a method of measuring a load current flowing through a current measurement resistor coupled between a source node and a load node includes: measuring a first voltage across a replica resistor when a first end of the replica resistor is coupled to the source node and a second end of the replica resistor is coupled to a reference current source; measuring a second voltage across the replica resistor when the second end of the replica resistor is coupled to the source node and the first end of the replica resistor is coupled to the reference current source; measure a third voltage across the current sensing resistor; and calculating a corrected current measurement of the load current based on the measured first voltage, the measured second voltage and the measured third voltage.