Steady-state characteristics of a self-excited series connected synchronous generator under unbalanced excitation capacitors

This paper presents a novel scheme on steady-state performance of an isolated three-phase self-excited series connected synchronous generator (SESCSG) under unbalanced excitation capacitors. The stator windings and the rotor windings of the SESCSG are connected in series with different phase sequence and the slip of this machine maintains to be 2. It is assumed that the Y-connected excitation capacitor bank is properly connected at the machine´s stator terminals. The values of excitation capacitance of both phase b and phase c are kept to be the same. The excitation capacitance of phase a is varied in order to investigate the unbalanced excitation effects on performance of the studied SESCSG. An approach based on three-phase induction machine model its employed to derive dynamic equations of the studied SESCSG. Both voltage and current unbalanced factors of the studied machine under no-load and loaded conditions are examined and compared. Experimental results obtained from a laboratory 1.1 kW induction machine driven by a DC motor are also performed to confirm the feasibility of the proposed method