Performance Degradation of Surface PMSMs with Demagnetization Defect under Predictive Current Control

Abstract

To control the current of a surface mounted permanent magnet synchronous machine fed by a two-level voltage source inverter, a large variety of control algorithms exists. Each of these controllers performs differently concerning dynamic performance and control- and voltage quality, but also concerning sensitivity to demagnetization faults. Therefore, this paper investigates the performance degradation of three advanced predictive controllers under a partial demagnetization fault. The three predictive controllers are: finite-set model based predictive control, deadbeat control, and a combination of both previous algorithms. To achieve this goal, the three predictive controllers are first compared under healthy conditions, and afterwards under a partial demagnetization fault. A PI controller is added to the comparison in order to provide a model-independent benchmark. Key performance indicators, obtained from both simulations and experimental results on a 4 kW axial flux permanent magnet synchronous machine with yokeless and segmented armature topology, are introduced to enable a quantification of the performance degradation of the controllers under a demagnetization fault. A general conclusion is that the deadbeat controller shows superior control quality, even under partial demagnetization.

Robust Model-Free Fault-Tolerant Predictive Control for PMSM Drive System

“…The discrete novel ULM in the speed loop is obtained from ( 6) (11) where T ss is the sampling period of the speed loop.…”

“…The q-axis reference current is predictively obtained by the discrete ULM (11), and the speed tracks the reference speed during the next control period. The reference speed ω * e (k + 1) is considered as ω e (k + 1) at (k + 1) T ss instant.…”

“…The control performance of the FCS-MPC method is easily affected by the parameter perturbations [8], such as stator inductance variation, stator resistance variation, and permanent magnet (PM) demagnetization faults [9]. In practical engineering applications, the resistance and inductance are affected by temperature and the operating conditions [10] the PM material of the rotor is affected by temperature, an external magnetic field, manufacturing defects, and so on [11], thus resulting in the demagnetization fault. The PM flux will reduce 20% of the initial flux per 100 • C increase in the ambient temperature [12].…”

A Review of Axial-Flux Permanent-Magnet Motors: Topological Structures, Design, Optimization and Control Techniques

“…With the further development of control theory and optimization theory, some studies have proposed novel control techniques for the dynamic response performance of AFPM motors, mainly including model predictive control (MPC) [115] and adaptive robust control (ARC) [116]. MPC is widely used in the field of machine drive and control due to its simple implementation, fast dynamic response and high tracking accuracy [117,118].…”