Study on Synchronization of Air-Core Compensated Pulsed Alternator Pairs

As a pulsed power supply, compensated pulsed alternator (CPA) has high power density and high energy density. In order to compensate the torque and gyroscopic effects during the discharge process and improve the ability of power supply, even number of similar counter-rotating alternators could be used, synchronously running in pairs and connecting in parallel to the load. However, there are unavoidable differences in parameters between machines, and this may result in a large difference between their discharge depth and discharge current waveforms and then cause the loss of life of some machines and rectifier devices as well as the decline of system output. Focusing on the synchronization of CPAs running in pairs, the factors that affect the synchronous operation of the machines are analyzed first. Then, the principle and characteristics of using different excitation circuit topologies to achieve synchronization are studied, and the limitations of such methods are pointed out. Finally, three active synchronization methods are proposed: excitation loop suppression (ELS), startup time regulation, and seed capacitor voltage regulation, hoping to make that the discharge depth tends to be the same and the difference of the discharge current amplitude to be in a small range. Simulation results show that all the three methods have good synchronization effect, and the effect of ELS is the best.