Feed Forward Compensation for Voltage Harmonic Reduction in Single Phase Inverter with Uncontrolled Rectifier and RLE Load

A simple method is presented in this paper for the reduction of voltage harmonics in single phase inverter with uncontrolled rectifier and RLE load. This method is based on a composite observer which is used for controlling inverters. In a composite observer different observers have been provided for the voltage and current signals. The distortion in the output voltage caused by the harmonics in the filter inductor can be estimated using the quadrature signals derived from the composite current observer. Using a composite voltage observer, the in-phase and quadrature voltage signals can be derived. These signals are converted into d-q components, using this components control circuit produces firing pulses for inverter. Feed forward compensation requires the extraction of the quadrature harmonics signals which are available from the composite observer. Composite voltage and current observer modeled. MATLAB simulation of composite observer based control scheme on inverter with uncontrolled Rectifier and RLE load condition are performed and output results are verified. Variation of THDv with feedback gain(h), and load resistance(R-L) are also studied.