基于尺寸优化的霍尔推力器磁路设计方法研究

Magnetic Circuit Design Method Based on Size Optimization in Hall Thrusters

针对当前霍尔推力器磁路设计主要依靠经验进行人工调节的现状,本文建立了高效率高质量的磁路优化设计方法,解决逐次调节单个磁路尺寸效率低,无法满足日益精细化磁场需求的问题.通过调研经过飞行验证的推力器,明确磁场参数描述方式及范围,提炼出了霍尔推力器设计的磁场准则;在此基础上,采用基于有限元方法的尺寸优化,将磁场要求嵌入磁路优化的约束中;在多约束算法的自动寻优下完成磁路设计.选取具有双磁屏的典型磁路结构形式作为初始磁路,以1.35 kW级推力器进行验证,结果表明,优化后磁路质量减轻34.9%,励磁功率减小5.6%,磁倾角从最大超过20°减小到6°以内,对称性得以改善,最大磁场强度增加8.3%,磁场梯度提高6.4%.本文提出的基于尺寸优化的磁路设计方法适用于各功率级霍尔推力器,允许磁场需求参数在较宽范围内变化并支持同时调节数十个关键尺寸,优化磁路较好地满足了磁场设计需求.

In view of the current situation that the design of the magnetic circuit of Hall thrusters mainly relies on manual adjustment by designers′experience,this paper establishes an efficient and high-quality magnetic circuit optimization design method to solve the problem of low efficiency in adjusting individual magnetic circuit sizes in a step-by-step manner,which cannot meet the increasingly refined magnetic field requirements.Through extensive research on flight-verified thrusters,the description method and range of magnetic field parameters are clarified,and the magnetic field criteria for Hall thruster design are refined.Based on this,size optimization based on finite element method is adopted,embedding the magnetic field requirements into the constraints of magnetic circuit optimization.Finally,the magnetic circuit design is completed under the automatic search and optimization of multi-objective optimization algorithm.A typical magnetic circuit structure form with double magnetic shields is selected as the initial magnetic circuit,and a 1.35kW-level thruster is used for verification.The results show that the optimized magnetic circuit quality is reduced by 34.9%,and the excitation power is reduced by 5.6%.The magnetic field symmetry is significantly improved.Meanwhile,the maximum magnetic field intensity is increased by 8.3%,and the magnetic field gradient is increased by 6.4%.The size-based optimization magnetic circuit design method proposed in this paper is suitable for Hall thrusters of various power levels,allowing the magnetic field requirement parameters to vary over a wide range and supporting the simultaneous adjustment of tens of key dimensions,optimizing the magnetic circuit to better meet the magnetic field design requirements.