Total Harmonic Distortion Control Research Articles

Design an Automatic Gain Adjustment for Shunt Active Power Filter Based on Total Harmonic Distortion Control for Harmonic Propagation Damping

AbstractIn order to harmonic propagation phenomenon damping, active power filters are installed on distribution systems.The installation of active power filter on buses, may itself cause harmonic propagation. The purpose of this paper is analyse the harmonic propagation also discuss the installation effect of a voltage-detection-based shunt active power filter that acts as a harmonic terminator. In order to meet this target because of the uncertain and variable nature of characteristic impedance,Zc, It is necessary to use active power filter with automatic gain adjustment. According to voltage harmonics detected at its installation bus, the active filter can adjust its control gain, keeping the voltage harmonics lower than a specified level, even if the characteristic impedance of the distribution line is unknown. In this paper, an automatic gain adjustment for active filter is designed based on keeping and controlling of total harmonic distortion in the allowable limitation according to IEEE-519 Std. Other features and benefits of using automatic gain adjustment are reduction of compensating current and hence losses reduction that these two results in reduction of the cost of active power filter. Finally the advantage of this controller compared with similar studies is simplicity, and its remoteness from the usual complexity.

Control of Total Harmonic Distortion in distribution Network using Compensation

Control of Total Harmonic Distortion in distribution Network using Compensation

Optimum control of total harmonic distortion in field programmable gate array-based cascaded multilevel inverter

Nowadays high quality power is essential for medical, research and industrial applications to produce good quality results and analysis. In this work an attempt has been made to improve the power quality by minimizing the harmonic content in the output voltage of a cascaded multilevel inverter using the selective harmonic elimination pulse width modulation technique. Sinusoidal PWM technique is used to generate the switching signals. A single phase nine-level cascaded multilevel inverter with identical DC supply is designed to reduce the harmonic components of the output voltage. Particle swarm optimization technique is applied to determine the optimum switching angles, thereby reducing some higher-order harmonics while maintaining the required fundamental voltage. This generalized technique can be extended to multilevel inverters with any number of levels. The total harmonic distortion is measured accordingly for different modulation indices. A prototype model of a field programmable gate array-based nine-level inverter has been designed, fabricated and tested. The results are presented and analyzed and hence the hardware results are verified with the simulation results.