Design and Simulation Analysis of a New Air-Core Permanent Magnet Compensated Pulsed Alternator with Segmental Squirrel-Cage

Compensated pulsed alternator (CPA) uses the flux compression effect of compensation elements to reduce transient inductance and release large current, and is used in the field of pulsed power with the advantages of high energy and power density. However, the traditional compensation elements are integral structures, such as compensation shield and short-circuit compensating winding. During the discharge process, especially at the highest current moment, the compensating potential directions are different under different poles, so the compensating eddy currents or compensating currents will be affected and weakened, which decreases the local compensation effect. To improve this disadvantage, this paper proposes a new air-core permanent magnet (PM) CPA with segmental squirrel-cage, which has the advantages of the PM excitation and air-core, small volume, light weight, compact structure and large output current. And at the highest current moment, the compensating current in each segment of the squirrel-cage will not be influenced by the compensating potential under different poles, thus the compensating effect is better. The simulation results verify that segmental squirrel-cage has more advantages than the conventional compensating elements. The research results are an important guide to the optimal design of compensating elements, and also provide a basis for the selection of the number of segments of the segmental squirrel-cage.