THREE-PHASE INDUCTION ELECTRICITY METER Russian patent published in 2001 - IPC

FIELD: electrical engineering, registration of active energy in four-wire A C networks with nominal frequency 50 Hz. SUBSTANCE: three-phase induction electricity meter has magnetic system incorporating three rotary elements put on supporting bracket. Each element includes core of voltage circuit and core of current circuit installed with air gap relative one another and counterpole put on symmetry axis of core of voltage circuit and forming air gap jointly with it. Meter also has register, braking magnetic system, mobile system, lower support and block with leads-out. Rotary element of first phase is mounted in center of upper part of supporting bracket, rotary element of second phase is placed in lower part of supporting bracket on the left side, rotary element of third phase is located in lower part of supporting bracket on the right side. Start of current coil of series circuit of first rotary element is connected to lead-out on block intended for connection of incoming line wire of first phase and its finish is linked to lead-out on block meant for connection of load. Start of voltage coil of parallel circuit of first rotary element is connected to lead-out on block for connection of zero wire and its finish is connected to lead-out on block meant for connection of incoming line wire of first phase. Start of current coil of series circuit of second rotary element is connected to lead-out on block intended for connection of incoming line wire of second phase and its finish is connected to lead-out on block for connection of load. Start of voltage coil of parallel circuit of second rotary element is connected to lead-out on block meant for connection of incoming line wire of second phase and its finish is connected to lead-out on block for connection of zero wire. Start of current coil of series circuit of third rotary element is connected to lead-out on block intended for connection of incoming line wire of third phase and its finish is connected to lead-out on block designed for connection of load. Start of voltage coil of parallel circuit of third rotary element is connected to lead-out on block meant for connection of zero wire and its finish is connected to lead-out on block intended for connection of incoming line wire of third phase. Air gaps between poles of cores of series circuits and poles of cores of parallel circuits are greater than air gaps between poles of cores of parallel circuits and counterpoles. Magnetic shunts of series circuit of each phase are assembled from sets of plates of electrical sheet steel with thickness of 0.3-1.2 mm. Braking magnetic system includes thermal compensator in the form of plate made of thermal magnetic material. EFFECT: raised precision and sensitivity of electricity meter. 4 cl, 4 dwg