Abstract :
For power loss measurements in large line shunt reactors, often characterized by loss tangents (or power factors) approaching 10-3, a non-frequency-sensitive bridge is required if accuracies approaching ±1.0 percent are to be realized. Unless the bridge balance is unaffected by the very small, but unavoidable, frequency shifts present in commercial power systems, sufficient balance resolution for this accuracy is difficult to obtain. This paper describes a non-frequency-sensitive bridge network which is direct reading in terms of conductance and susceptance of the reactor under test. Use is made of operational amplifiers to help shape the desired frequency characteristic. Resolutions approaching one part in 106 can be realized. Also described are means and procedures for calibrating the bridge in terms of a simulated "standard" reactor which can have either zero loss or a predetermined positive or negative loss.
