Abstract: An electronic utility meter includes a sensor module, a measurement module, and a removable expansion module. The sensor module connects to the electrical system of a facility, and includes voltage and current sensors. The voltage and current sensors are operable to receive voltage and current signals from the electrical system and generate measurement signals therefrom. The measurement module includes a measurement circuit operable to receive measurement signals and generate energy consumption data therefrom. The measurement module further includes a device for communicating information relating to the energy consumption data. The measurement module is configured to couple to the sensor module to connect the measurement circuit to the voltage and current sensors. The removable module is interposed between the sensor module and the measurement module. The removable module operably couples the measurement circuit to the voltage and current sensors.

Abstract: The present invention includes an electrical utility meter operable to measure power consumption. The method detects and compensates for one or more wiring errors that affects the power consumption measurement of the electrical utility meter. The method includes the steps of: obtaining measured phase angle data for a plurality of phases in a polyphase electrical system; periodically performing one or more diagnostic tests using the measured phase angle data to determine whether a wiring error is present, automatically adjusting the operation of the electrical utility meter to effect a compensation for the wiring error, said compensation increasing an accuracy of power consumption measurement of the electrical utility meter. The meter is operable to detect and compensate for wiring errors including polarity errors and cross phasing errors. According to another method of the present invention, the meter is operable to determine automatically the service type to which it is connected.

Abstract: Disclosed is a method and arrangement for use in an electrical utility meter, the electrical utility meter operable to be connected to a plurality of electrical service types. The arrangement is operable to identify a present service type, the present service type being one of the plurality of electrical service types to which the electrical utility meter is connected. The arrangement comprises: conversion circuit for obtaining measured voltage magnitude and phase angle data for a plurality of phases in a polyphase electrical system; a memory; and a processor connected to said memory and said conversion circuit. The processor is operable to execute programming steps stored in the memory to receive the measured voltage magnitude and phase angle data from the conversion circuit and identify the present electrical service type based on the measured voltage magnitude and phase angle data.

Abstract: Apparatus for injection voltage compensation in series into an electric power line includes an inverter or other controlled voltage source which wye connects the secondary windings of a three-phase transformer to the load end of the electric power line. The transformer, which could already be present for meeting load requirements, has its primary winding connected to the source end of the electric power line and sustains the saturation currents rather than the inverter in response to faults on the source side of the transformer. Preferably, a three-phase inverter with a common dc link is used. For active power line conditioner (APLC) action, a second, also preferably a three-phase, inverter is connected in parallel to the load end of the electric power line and to the common dc link. This parallel inverter provides harmonic and reactive power compensation and also supplies the real power requirements of the wye connection inverter.

Abstract: A transient reducing capacitor switching device that switches grounded capacitors into a multi-phase power line, wherein each phase of the line carries an AC voltage signal that cycles its polarity. A first switch is associated with a first grounded capacitor, a second switch is associated with a second grounded capacitor and a third switch is associated with a third grounded capacitor. A switch controller switches the first capacitor into the first phase of the power line substantially when the voltage signal in the first phase crosses zero potential. The switch controller has a delay that delays at least one-quarter of one cycle after the first capacitor was switched into the first phase, then switches the second capacitor into the second phase of the line substantially when the voltage signal in the second phase crosses zero potential.

Abstract: An electronic utility meter includes a sensor module and a removable measurement module. The sensor module connects to the electrical system of a facility and includes voltage and current sensors. The voltage and current sensors is operable to receive voltage and current signals from the electrical system and generate measurement signals therefrom. The sensor module further includes an electrically safe interface. The removable measurement module includes a measurement circuit operable to receive measurement signals and generate energy consumption data therefrom. The measurement module also includes a device for communicating information relating to the energy consumption data. The electrically safe interface of the sensor module operably connects the voltage and current sensors to the measurement circuit, and further prevents physical contact of a human operator with the received voltage and current signals from the electrical system when the measurement module is removed from the sensor circuit.

Abstract: A controller for a voltage regulator has an input keypad for designating selected operating parameters of the voltage regulator. The keypad is formed with a dedicated function portion and a menu navigation portion, and the parameters are divided into first and second categories. The controller has a display for displaying the parameters, and a computer is connected to the input and to the display for controlling the display in response to activation of the keypad. Any parameter in the first category can be displayed on the display by activation of the dedicated function portion of the keypad. Any parameter in the second category can be displayed by activation of the menu navigation portion. The menu navigation portion can optionally also be used to control display of parameters in the first category.