Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 6

total harmonic distortion (THD) Related Abstracts

6 Estimation of Harmonics in Three-Phase and Six-Phase-Phase (Multi-Phase) Load Circuits

Authors: Deepak Kumar, Zakir Husain

Abstract:

The harmonics are very harmful within an electrical system and can have serious consequences such as reducing the life of apparatus, stress on cable and equipment etc. This paper cites extensive analytical study of harmonic characteristics of multiphase (six-phase) and three-phase system equipped with two and three level inverters for non-linear loads. Multilevel inverter has elevated voltage capability with voltage limited devices, low harmonic distortion, abridged switching losses. Multiphase technology also pays a promising role in harmonic reduction. Matlab simulation is carried out to compare the advantage of multi-phase over three phase systems equipped with two or three level inverters for non-linear load harmonic reduction. The extensive simulation results are presented based on case studies.

Keywords: Inverter, Harmonics, fast Fourier transform (FFT), ripples, total harmonic distortion (THD)

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5 A Novel Idea to Benefit of the Load Side’s Harmonics

Authors: Hussein Al-bayaty

Abstract:

This paper presents a novel idea to show the ability to benefit of the harmonic currents which are produced on the load side of the power grid. The proposed circuit contributes in reduction of the total harmonic distortion (THD) percentage through adding a high pass filter to draw harmonic currents with 150 Hz and multiple frequencies a and convert them to DC current and then reconvert it to AC current with 50 Hz frequency in order to feed different loads. The circuit has been designed, investigated and simulated in the MATLAB, Simulink program; the results will be assessed and compared the two cases: firstly, the system without adding the new circuit. Secondly, with adding the high pas filter circuit to the power system.

Keywords: total harmonic distortion (THD), harmonics elimination, passive filters, filter circuit

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4 Execution of Optimization Algorithm in Cascaded H-Bridge Multilevel Inverter

Authors: K. Ramani, M. Suresh Kumar

Abstract:

This paper proposed the harmonic elimination of Cascaded H-Bridge Multi-Level Inverter by using Selective Harmonic Elimination-Pulse Width Modulation method programmed with Particle Swarm Optimization algorithm. PSO method determine proficiently the required switching angles to eliminate low order harmonics up to the 11th order from the inverter output voltage waveform while keeping the magnitude of the fundamental harmonics at the desired value. Results demonstrate that the proposed method does efficiently eliminate a great number of specific harmonics and the output voltage is resulted in minimum Total Harmonic Distortion. The results shown that the PSO algorithm attain successfully to the global solution faster than other algorithms.

Keywords: Particle Swarm Optimization (PSO), total harmonic distortion (THD), multi-level inverter, Selective Harmonic Elimination Pulse Width Modulation (SHEPWM)

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3 Comparative Study between Classical P-Q Method and Modern Fuzzy Controller Method to Improve the Power Quality of an Electrical Network

Authors: M. S. Boucherit, A. Morsli, N. Ould Cherchali, A. Tlemçani

Abstract:

This article presents two methods for the compensation of harmonics generated by a nonlinear load. The first is the classic method P-Q. The second is the controller by modern method of artificial intelligence specifically fuzzy logic. Both methods are applied to an Active Power Filter shunt (APFs) based on a three-phase voltage converter at five levels NPC topology. In calculating the harmonic currents of reference, we use the algorithm P-Q and pulse generation, we use the intersective PWM. For flexibility and dynamics, we use fuzzy logic. The results give us clear that the rate of Harmonic Distortion issued by fuzzy logic is better than P-Q.

Keywords: Fuzzy Logic Controller, total harmonic distortion (THD), P-Q method, pulse width modulation (PWM), shunt active power filter (sAPF)

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2 Analysis of a Power Factor Correction Converter for Light Emitting Diode Driver Application

Authors: S. J. Bindhu, Edwina G. Rodrigues, A. V. Rajesh

Abstract:

This paper proposes a switched capacitor based driver circuit for high power light emitting diodes with a front end rectifier. LEDs are low-voltage light sources, requiring a constant DC voltage or current to operate optimally. LEDs, therefore, require a device that can convert incoming AC power to the proper DC voltage, and regulate the current flowing through the LED during operation. Proposed topology has a front end converter. It is an AC-DC rectifier that works on bridgeless boost topology which shapes the input current waveform. The front end converter is followed by a DC-DC converter which provides a constant DC voltage across the LEDs. A 12V AC input is given to the input of frontend converter which rectifies and boost the voltage to 24v DC and gives it to the DC-DC converter. The DC-DC converter converts the 24V DC and regulates this constant DC voltage across the LEDs.

Keywords: total harmonic distortion (THD), bridgeless rectifier, power factor correction(PFC), SC converter

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1 [Keynote Talk]: Implementation of 5 Level and 7 Level Multilevel Inverter in Local Trains of Mumbai

Authors: Swati Sharma, Sharvari Sane, Sanjay K. Prasad

Abstract:

Local trains are the lifelines of Mumbai city. Earlier 1500 Volt D.C. supply, is now completely and successfully converted into 25 KV A.C. in central, western and harbour routes. This task is the outcome of the advancement in the area of power electronics. Author has already done the comparative study between D.C. and A.C. supply of traction and predicted the serious problem regarding the harmonics. In this paper, the simulation for 5 level as well as 7 level multilevel inverter has been done which is the substitute for the present cascade type inverter. This paper also showed the reduced level of Total Harmonic Distortion (THD) in the traction system.

Keywords: Harmonics, Multilevel Inverter, total harmonic distortion (THD), traction sub station (TSS)

Procedia PDF Downloads 242