Modelling of synchronous reluctance motor in Simulink dynamic modelling and control implementation

Abstract

Synchronous reluctance motors (SynRMs) offer high-efficiency, magnet-free drives, but their performance depends strongly on accurate modelling of saliency and the associated control strategy. This thesis develops a transparent, first-principles dq-axis model of a 30-kW SynRM in Simulink using only elementary blocks such as gains, integrators and trigonometric functions. Machine parameters are taken from a finite-element-validated prototype, ensuring realistic inductances and saliency ratios. Two control schemes are applied to the same model: scalar v/f control, implemented with ideal sinusoidal voltages for dynamic-performance evaluation and extended with sinusoidal PWM (SPWM) for harmonic analysis, and field-oriented control (FOC) with SPWM and PI regulation of speed and dq currents. Their performance is evaluated under no-load and rated-load conditions in terms of torque response, speed regulation, torque ripple and current total harmonic distortion (THD).

Results show that FOC delivers faster transients, stronger disturbance rejection and consistently lower torque ripple and THD compared with scalar control, although both achieve the required steady-state speed. A structured sensitivity analysis—varying saliency ratio, mechanical inertia and solver step size—further assesses the robustness of the model. The study demonstrates that a carefully constructed analytical SynRM model can reproduce essential drive dynamics while remaining computationally efficient and fully transparent. The resulting framework provides a reproducible basis for research and teaching and a platform for future extensions such as maximum-torque-per-ampere, direct torque control and predictive control.