Minimization of control loop sampling rates

This thesis explores the problem of achieving high performance and robustness in the field-oriented control (FOC) of permanent magnet synchronous motors (PMSMs) while reducing the sampling rate. The objective is to investigate alternative approaches to optimise motor control systems, aiming to strike a balance between performance, robustness, and minimum sampling rate. To tackle this challenge, a novel method is proposed that combines H-infinity performance and decoupling techniques to enable a potential reduction in the sampling period. The thesis begins with an in-depth analysis of the SISO (Single-Input Single-Output) case, where the H-infinity structured controller is introduced. The results demonstrate improved bandwidth and robustness compared to traditional control methods. Building upon the SISO analysis, the investigation extends to the MIMO (Multi-Input Multi-Output) case. The implementation of decoupling methods, including the use of predicted state and PI decoupling, is explored to enhance system performance. Comparative evaluations are conducted, demonstrating the trade-offs between bandwidth, peak sensitivities, and robustness in different configurations. Furthermore, a generalized algorithm is developed for the MIMO case, aiming to find an optimal controller that satisfies the desired constraints. While the optimization process incurs increased complexity, a controller that accommodates higher delays is obtained. The proposed method offers potential for a significant reduction in the sampling period, aligning with SABCA's objective of optimizing motor control processes.