Control Strategies of Three - Phase Distributed Generation Inverters and Multilevel Inverter for Grid Unbalanced Voltage Compensation

Due to the wide spread of power electronics equipment in modern electrical systems, the increase of the harmonics disturbance in the ac mains currents has became a major concern due to the adverse effects on all equipment. Power electronic converters are commonly used for interfacing distributed generation (DG) systems to the electrical power network. However, the unbalanced voltage compensation may cause adverse effects on the IFCs' operation such as output active power oscillation and DC link voltage variations. Moreover, since the compensation is realized through the available rating of IFCs, it is equally important to consider the effectiveness of control strategy for unbalanced voltage compensation. Specially, the first control strategy aims at minimizing the IFC's active power oscillation and reducing the adverse effects of unbalanced voltage compensation on IFC's operation. In DG systems a fast and accurate positive-sequence, fundamental grid voltage frequency and magnitude tracking is required to synchronize grid connected converter systems with the mains. The proposed System deals with a Multi level inverter for DG systems mitigating power quality issues, such as harmonics and reactive power compensation for grid-connected operation. It performs the nonlinear load current harmonic compensation, mitigates harmonics yielding more accurate and pure sine wave output. So Instead of using inverter we can use multilevel inverters in the power system equipment.