Dynamic Voltage Restorer based on Mixed Modular Multi-level Inverter for compensation voltage sag, swell and flicker in power distribution grids

In this paper, a new structure of Dynamic Voltage Restorer (DVR) based on a mixed modular multi-level inverter (M3I) is proposed, which is capable of compensating for voltage sag, swell and flickers for sensitive loads. The mixed modular multi-level inverter is made up of fewer IGBTs and less circuitry than similar structures. Due to the low number of DC inputs and the lack of electrolyte capacitors in the inverter structure, the control of this inverter is simple to produce the desired voltage. This inverter is made up of three inverters, a single-phase bridge, a triple-inverters, and auxiliary cells to increase the number of line-to-line voltage levels. The inverter also has the ability to produce a number of higher output voltage levels and less harmonic distortion, which makes this structure possible in the power quality compensation grid. The switching method of controlling the closest NLC level in the proposed inverter is used to create the desired waveform. The pre-sag control method was used to control the proposed DVR and use the synchronous reference frame (SRF) method to anomalous detection of grid voltage fluctuations. To investigate and validate the proposed DVR performance, simulations are carried out in the MATLAB / SIMULINK software environment, and the results indicate that the proposed DVR is desirable for optimum performance and performance in voltage sag, swell, and flicker of the power distribution grids.