AC RESISTANCE MEASURING METHOD OF POWER CABLE ELECTRIC CONDUCTOR

摘要

PURPOSE:To measure an AC resistance with high accuracy by a power source of a small capacity by placing a power cable in a hollow columnar electric conductor and forming a closed circuit together with a power cable electric conductor, and detecting a voltage drop of a prescribed section through a pair of lead wires of a mirror symmetry of the outside periphery of the columnar electric conductor. CONSTITUTION:A power cable 10 is placed in a hollow columnar electric conductor 11, and a closed circuit C is formed by the electric conductor 11 and an electric conductor 1 of the cable 10. Each end of a pair of lead wires 12, 13 wound around in a mirror symmetry to the outside periphery of this electric conductor 11 is connected to both ends A, B of a prescribed section of the electric conductor 1, and when a voltage drop of this section of the electric conductor 1 is detected through a bridge circuit 2, a power loss of the electric conductor 11 of the circuit C in which the conductive section is large enough, and also the electric conductor is made of steel, etc. can be reduced remarkably, and also the voltage drop quantity supplied to the bridge circuit by the lead wires 12, 13 contains no portion influenced by an induced noise generated by a magnetic field by the cable 1. In this way, an AC resistance of the power cable electric conductor is measured with high accuracy of a power source of a small capacity.