SYSTEM FOR TESTING ENERGY METERS IN A THREE-PHASE HIGH-VOLTAGE NETWORK

摘要

The proposed system for testing energy meters in a three-phase high-voltage network contains three complete measuring units. Each measuring unit contains a calibrated measuring current transformer, a reference single-phase electric power meter, two current-to-voltage converters, two measuring voltage transformers, and an independent power-supply unit. The casings of the said devices are connected to earth. The input terminals of the current circuit of the reference electric power meter are connected to the output terminals of the secondary winding of the current transformer. As the primary winding of the current transformer, the corresponding phase conductor of the network is used. The input terminals of the first current-to-voltage converter are connected in series with the primary winding of the voltage transformer that is connected in the phase circuit of the tested electric power meter, and the output terminals are connected to the input terminals of the voltage circuit of the reference electric power meter. The input terminals of the secondary current-to-voltage converter are connected in series with the primary winding of the voltage transformer that is connected in the phasecircuit of the reference electric power meter, and the output terminals are connected to the input terminals of the voltage circuit of the tested electric power meter.