Patent ID: 6566895
Filing Date: 2003-05-20
Classification: G01R

Abstract:
An apparatus for measuring individual phase voltages and phase currents from a delta power source having a first delta source, a second delta source, and a third delta source, for use by a delta load circuit having a first delta load, a second delta load, and a third delta load, said apparatus comprising:an input delta-wye transformer having a first delta input coil, a second delta input coil, a third delta input coil, a first wye input coil with a first wye input connection, a second wye input coil with a second wye input connection and a third wye input coil with third wye input connection, a neutral point connection of said first wye input coil and said second wye input coil and said third wye input coil, said first delta input coil being connected across said first delta source, said second delta input coil being connected across said second delta source, and said third delta input coil being connected across said third delta source; an output wye-delta transformer having a first wye output coil with a first wye output connection, a second wye output coil with a second wye output connection, and a third wye output coil with a third wye output connection, a first delta output coil, a second delta output coil, and a third delta output coil, said first delta output coil being connected across said first delta load, said second delta output coil being connected across said second delta load, and said third delta output coil being connected across said third delta load; a first current conductor, a second current conductor, and a third current conductor, said first current conductor electrically connecting said first wye input connection and said first wye output connection, said second current conductor electrically connecting said second wye input connection and said second wye output connection, and said third current conductor electrically connecting said third wye input connection and said third wye output connection; and a first current probe for measuring current through said first current conductor, a second current probe for measuring current through said second current conductor, and a third current probe for measuring current through said third current conductor.