Permanent magnet synchronous motors (PMSM) today represent one of the key solutions in electric drives, where high efficiency, compactness, and precise control are required. Their mathematical models can be complex, as they include nonlinear dependencies and multiple coupled differential equations. For the development of control systems, simulation tools are therefore used, as they enable the analysis of different operating conditions and the verification of the applied control algorithms.
In this thesis, a mathematical model of a surface-mounted permanent magnet synchronous motor (SPM) was developed, based on which a simulation model was built in MATLAB/Simulink. The model is based on the d-q theory, where three-phase voltages and currents are transformed into a two-axis coordinate system using the dq0 transformation, which significantly simplifies the analysis and enables the use of simpler control structures.
The control system was designed as a cascaded structure, where the inner current loops control the d- and q-axis current components with PID controllers, while the outer speed control loop is realized with a PI controller. A speed reference ramp was also added, providing a more realistic response of the fan drive and preventing overloads. The load characteristic of the R09/450 fan was used to ensure that the model more accurately reflects the actual operating conditions.
The simulation results confirm that the system ensures stable and accurate speed control in various operating points and that the implemented field-oriented control (FOC) method leads to fast and reliable transitions between operating states. The thesis provides a basis for further development, where the model could be extended with PWM modulation and validated by comparing the results with experimental measurements on a real fan drive.
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