Multi-stage LCR Square-Wave Circuit as Practical Pulsed Power Supply for Electromagnetic Railgun

Using electromagnetic force to directly accelerate projectiles to hypervelocity, railguns can be applied in the military field. The characteristics of existing Pulse Forming Network (PFN) based on energy-storage capacitors as Pulsed Power Supply (PPS) driving railguns are analyzed, which has such shortcomings as low system efficiency and low firing rate. A kind of PPS model for multi-stage parallel LCR square-wave circuits is proposed based on such theories as Fourier series principle, LCR attenuation oscillation circuit characteristics, and Kirchhoff’s current law. The matching relationship among such parameters as capacitance, inductance, and resistance of multi-stage parallel LCR square-wave circuits has been designed according to theoretical analysis. Taking a 10-ms pulse width and 2.4-MA amplitude as an example, a five stage parallel LCR square-wave circuit is designed to drive railguns with the sliding contact resistance RR = 0.5 mΩ and the load inductance LR = 4 μH. Then the above scheme is calculated using Matlab software, and the results show that the fluctuation rate of current amplitude is less than 10%, and about 64% of the total electric energy is residual and can be fully recovered in the capacitors after one round. The above new PPS work driving electromagnetic railguns with high firing rate and high firing efficiency is of great significance for promoting the military application of electromagnetic rail gun technology.