Multiphase railgun systems: a new concept

The authors investigate multiphase railguns powered by multiphase compulsators. The polyphase system offers several advantages over the single-phase system. The multiphase compulsator relaxes the strong dependence between the current pulse width necessary for the railgun and the design parameters of the generator, thus allowing the compulsator to be designed for optimum power density and electromechanical energy conversion. The authors examine the two-, three-, and six-phase systems. They also explore different methods of achieving high acceleration ratios in multiphase railgun systems. Some of the methods analyzed are ramping up the field current of the compulsator to counter the back electromotive force of the gun, utilizing a railgun with varying inductance per unit length, and using an external variable inductor in series with the compulsator. The different features of each method are highlighted using simulation results.>