Determination of equivalent circuit constants of synchronous machines from the extended Dalton‐Cameron method

This paper presents a method of determining the equivalent circuit constants which accord with the physical construction of synchronous machines, using the dc decay testing method with the rotor in arbitrary position (proposed by the authors and called the extended Dalton–Cameron method). The conventional Dalton–Cameron method calculates the direct- and quadrature-axis subtransient reactance from a standstill response test in any arbitrary rotor position using a single-phase power supply. The extended Dalton–Cameron method determines the direct- and quadrature-axis operational impedances for each slip from a standstill response test using a small-capacity dc power supply. The direct- and quadrature-axis operational impedance loci thus obtained synchronous machine constants (subtransient, transient, and synchronous reactances) are used to estimate the direct- and quadrature-axis equivalent circuit constants which accord with the physical construction of synchronous machines. As an example, equivalent circuit constants are determined for a 10-kW laminated salient-pole-type synchronous machine with damper winding. The validity of the equivalent circuit constants is confirmed by comparing the calculated resistance and leakage reactance of the field winding determined from the operational impedance when the terminals are short-circuited, to those when the terminals are connected to an external resistance. © 2001 Scripta Technica, Electr Eng Jpn, 138(1): 56–67, 2002