Analysis of the current total harmonic distortion for different single-phase inverters for grid-connected pv-systems

2005 ◽  
Vol 87 (1-4) ◽  
pp. 529-540 ◽  
Author(s):  
M. Sidrach-de-Cardona ◽  
J. Carretero
Keyword(s):  
Single Phase ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Pv Systems

scholarly journals Total Harmonic Distortion Oriented Finite Control Set Model Predictive Control for Single-Phase Inverters

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3467 ◽  
Author(s):  
Po Li ◽  
Ruiyu Li ◽  
Haifeng Feng
Keyword(s):  
Model Predictive Control ◽  
Cost Function ◽  
Predictive Control ◽  
Single Phase ◽  
Tracking Error ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Finite Control ◽  
Control Set ◽  
The Cost

Inverters are commonly controlled to generate AC current and Total Harmonic Distortion (THD) is the core index in judging the control effect. In this paper, a THD oriented Finite Control Set Model Predictive Control (FCS MPC) scheme is proposed for the single-phase inverter, where a optimization problem is solved to obtain the switching law for realization. Different from the traditional cost function, which focuses on the instantaneous deviation of amplitude between predictive current and its reference, we redesign a cost function that is the linear combination of the current fundamental tracking error, instantaneous THD value and DC component in one fundamental cycle (for 50 Hz, it is 0.02 s). Iterative method is developed for rapid calculation of this cost function. By choosing a switching state from a FCS to minimize the cost function, a FCS MPC is finally constructed. Simulation results in Matlab/Simulink and experimental results on rapid control prototype platform show the effect of this method. Analyses illustrate that, by choosing suitable weight of the cost function, the performance of this THD oriented FCS MPC method is better than the traditional one.

scholarly journals Harmonics reduction of a five-level inverter by unbalanced carriers and over-modulation techniques

2018 ◽  
Vol 7 (3) ◽  
pp. 1059
Author(s):  
Mustafa Fawzi Mohammed ◽  
Ali Husain Ahmad ◽  
AbdulRahim Thiab Humod
Keyword(s):  
Fundamental Frequency ◽  
Output Voltage ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Modulation Method ◽  
Labview Software ◽  
Design And Implementation ◽  
Modulation Techniques ◽  
Multi Level

The most concerns in the inverter's design are about, how to make the output voltage of the inverter sinusoidal at the desired fundamental frequency with low total harmonic distortion (THD). This paper presents a design and implementation of single-phase five-level inverter which is powered by single dc source and based on T-type multi-level inverters construction. The proposed inverter is built mainly by six IGBTs and two diodes. The used modulation technique is based on using two triangular carriers at 2000 Hz frequency and shifted by phase opposition disposition (POD) method. The carriers are made slightly unbalanced with their amplitudes. The over-modulation method is also introduced in the design to get the lowest possible THD effect without using filters. The inverter is simulated by MATLAB SIMULINK, implemented practically, and tested with the help of LabVIEW software.  

scholarly journals Multivariable polynomial fitting of controlled single-phase nonlinear load of input current total harmonic distortion

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 137-142
Author(s):  
Roman Sikora ◽  
Przemysław Markiewicz ◽  
Wiesława Pabjańczyk
Keyword(s):  
Mathematical Model ◽  
Power Systems ◽  
Single Phase ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Polynomial Fitting ◽  
Nonlinear Load ◽  
Multivariable Polynomial ◽  
Led Luminaire

Abstract The power systems usually include a number of nonlinear receivers. Nonlinear receivers are the source of disturbances generated to the power system in the form of higher harmonics. The level of these disturbances describes the total harmonic distortion coefficient THD. Its value depends on many factors. One of them are the deformation and change in RMS value of supply voltage. A modern LED luminaire is a nonlinear receiver as well. The paper presents the results of the analysis of the influence of change in RMS value of supply voltage and the level of dimming of the tested luminaire on the value of the current THD. The analysis was made using a mathematical model based on multivariable polynomial fitting.

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