Asynchronous motor speed control with three phase seven level inverter

In this thesis, firstly general information about multi-level inverter topologies, SPWM control technique, IGBTs, asynchronous motor and asynchronous motor speed control methods are given. In the Matlab / Simulink program, the three-phase seven-level inverter circuit is constructed by selecting the cascade (serial) connected inverter topology. In the inverter circuit, IGBTs are used as switching circuit elements and capacitors are connected to DC sources in order to prevent current imbalance in these circuit elements. The low-pass filter L-C circuit is connected to reduce the total harmonic distortion and convert it to the sinus signal at the voltage and current signals obtained. With the designed three phase seven level inverter, an asynchronous motor with 15 kW output power has been applied. Speed control with asynchronous motor PI controller and V / f ratio constant. In the analysis of the performance parameters obtained from the output of the asynchronous motor, %92.8 efficiency was obtained.