The pulsed power supply based on air-core pulsed alternator can output a current up to the megampere level in an extremely short time, with outstanding advantages of high energy density, high power density, and high integration degree. It has been a preferred power source for electromagne-tic launch (EML) system. To achieve the required amplitude of the output current pulses, the field current of the alternator is often required to be up to tens of thousands ampere level. Therefore, the self-excitation method is often used to achieve the required field current in very short time. How to maintain high field current after the self-excitation process, is the key technology of the air-core pulsed alternator to achieve multiple railgun projectile launches in short time. However, the operation principles already proposed are only suitable to achieve single railgun projectile launch after the field current is built by self-excitation. If multiple railgun projectile launches are required, multiple self-excitations are required, which will not only require long time, but also causes a large amount of losses generated in the field winding. In this paper, a novel operation principle of the EML system, based on the air-core pulsed alternator, to achieve multiple electromagnetic railgun projectile launches after a self-excitation process is introduced. Based on the operation principle above, the changing trend of the field current is modeled and analyzed. Finally, the entire operation process of the EML system is simulated to verify the feasibility of the proposed operation principle.

Air-core pulsed alternator, EML system, self-excitation, novel operation principle.