Between the control system and the electric motor, a power connection in the form of a three-phase converter is essential. This converter must enable fast, precise, and safe operation even at high switching frequencies, and therefore must be appropriately designed in terms of topology and electromagnetic compatibility. As part of the master's thesis, a three-phase two-level inverter was designed and built, using hybrid SiC FET transistors UJ4SC075018B7S. The inverter also includes a measurement system, user interface, and protective functions. The modules require different voltage levels, which are provided by isolated low-voltage power supplies. To address the issue of an adverse high-impedance power connection, a power circuit of a DC-link is used, implemented with a DC-link capacitor of suitable capacitance.
Rapid Control Prototyping (RCP) enables the transfer of algorithms from the simulation environment to the real system without the lengthy process of final hardware development. To implement RCP, a real-time (RT) device is required. This work describes the configuration and use of the Speedgoat Baseline S RT device with two IO397 modules and a temperature module IO172.
For reliable operation, special attention must be paid during PCB design – performed in Altium Designer – especially to proper isolation between the high-voltage (HV) and low-voltage (LV) parts of the circuit, and to the correct routing of all fast and measurement signals.
After completing the circuit and verifying basic functions, test programs and applications were developed using graphical programming in Matlab/Simulink for passive single phase and three-phase loads, as well as for an asynchronous motor, confirming the connectivity of the entire system.
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