Optimal Design of Compact 100-kA Spiral Inductor in High-Energy Pulse Power Supply of Laser Fusion Facility

Abstract

The spiral inductor is one of the components in the pulse power supply of large laser fusion facility, which plays the role of limiting discharge current and protecting system components. Strong electromagnetic stress and high temperature rise caused by large current greatly limit the current capacity of the spiral inductor and increase the possibility of inductor damage. Taking the 100-kA pulse current as the design goal, based on the particle swarm optimization (PSO) algorithm and the elliptic integral Bartky’s transformation method, a new numerical calculation method for calculating the inductance value of the spiral inductor is established, which can quickly determine the inductance structure parameters that meet the circuit parameter requirements and have the minimum volume and ensure that the temperature rise of the inductor metal coil is within the allowable range. Through the electromagnetic structure coupling simulation, the electromagnetic stress distribution of the inductor is obtained. It is found that the maximum electromagnetic stress appears on the innermost coil. By increasing the radial thickness of the inner insulation frame of the coil, the stress distribution on the inner coil can be reduced and the mechanical strength of the inductor can be satisfied. Experimental results show that the spiral inductor can withstand 171-kA current and 622-kJ energy, and it can meet the requirements of the most serious fault caused by one capacitor internal insulation breakdown.