STABILITY OF 3/3-PHASE DOUBLE WINDING GENERATOR WITH SIMULTANEOUS AC AND RECTIFIED DC LOAD

If the parameters of the 3/3-phase double winding generator and its load do not match, low-frequency oscillation will occur in the system and result in its breakdown. In order to study the conditions for the stable operation of the system, based on the equivalent models of 3/3-phase double winding generator with simultaneous AC and rectified DC load, the linearized model and the corresponding state space mathematical model are developed for the system. The criterion of operation stability for the system under small disturbance, including the formulae for calculating equivalent dynamic resistance and critical resistance, are obtained by using Routh criterion. A physical interpretation is given to the criterion of operation stability. The effects of generator parameters, quadrature-axis stability winding and load on operation stability of the system are studied in detail. The comparison between the calculated and experimental results verified the validity of the mathematical model and analytical method.