HARMONIC MEASURING METHOD

摘要

PROBLEM TO BE SOLVED: To measure the harmonic characteristics without requiring a dedicated current injector by injecting currents of a plurality of frequencies from a master station to a harmonic injecting point at the time of harmonic measurement. SOLUTION: Each section switch 3 is provided with an instrument current transformer 11 and an instrument potential transformer 12 closely to the upstream side thereof and further provided a normal slave station 13a or a slave station 13b having harmonic measuring function. When the harmonic characteristics are measured for a distribution system 1 of distribution line carrier communication system, the current injector at a master station 4 for distribution line carrier communication is switched from communication signal injection to injection of currents having frequencies higher and lower than an interesting harmonic. Since both the distribution line carrier communication and the harmonic measurement are performed at the master station 4, the harmonic characteristics of a distribution line having a distribution line carrier communication system switch control function can be measured with high facility efficiency without requiring a current injector dedicated for harmonic measurement.