Abstract
Voltage fluctuations in unregulated microsatellite buses introduce strong coupled nonlinearities in momentum wheel systems, which consist of power supply (PS) and permanent magnet synchronous motor (PMSM) subsystems. Voltage fluctuation-induced coupling can dramatically affect the performance of momentum wheel systems. To address this specific challenge, this paper proposed a systematically dual-loop controller based on feedback linearization (DLC-FL), mixing$H_{2}/H_{\infty }$and linear quadratic regulator (LQR) control strategies. For the inner-loop control, the affine nonlinear PS-PMSM model is linearized using differential geometric techniques, and mixed$H_{2}/H_{\infty }$control is applied to this linearized coupled model to guarantee robust stability and dynamic response characteristics. Regarding the outer-loop control, we propose a LQR framework integrated with Gaussian Distribution Particle Swarm Optimization (GDPSO) algorithm for parameter tuning. Simulation results show that the proposed controller has a 64% reduction in speed step response time, 51% mitigation of DC bus voltage fluctuations, and the proposed GDPSO achieves 50% faster convergence compared to conventional particle swarm optimization methods. Hardware experiments also validate superior performance, with a total harmonic distortion of only 7.96%, offering an effective solution for high-precision control of multivariable nonlinear electric servo systems.