A Direct-and Quadrature-Axis Representation of a Parallel AC and DC Power System

Some typical results of an analog computer study of a parallel ac-dc power system are given in a companion paper. Commutations of both inverter and rectifier bridges are among the simulations detailed. Recognizing that individual commutations are of negligible importance for many phenomena, a simpler system simulation seemed feasible on the analog computer, and this was begun. Not only was the simulation improved but transient phenomena could be examined, which in real time may be of longer duration than simulated and accuracy will be retained. This is of special importance in studying electromechanical transients in parallel ac-dc power systems, especially during sudden load changes. The validity of the new simulation is established.