A Multirate Model Predictive Current Control of GaN Power Amplifiers for Voice Coil Motors

GaN power amplifiers (PA) can achieve low current ripple for voice coil motors. However, due to the limited sampling frequency, the controller cannot achieve control updates in each switching period, which degrades the performance of the GaN PA. Therefore, this paper proposed a novel multirate model predictive current control (MRMPCC) for the GaN PA. The predictive model of the GaN PA is derived. The feedback correction is applied to eliminate steady-state errors. The control law of the MRMPCC is obtained through rolling optimization. The simulation analysis of the MRMPCC is performed. The current response speed of this method is improved by 44.11% compared to the PID method. The effectiveness of the proposed method is verified.