A High Performance Rectifier

8/6/2019 A High Performance Rectifier

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By

Rajender Goud.K

1BM09LPE11

2

nd

sem,M.Tech


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A new circuit topology is introduced, to build up a power electronic rectifier forelectrical power generation from marine currents.

The new power converter seems able to guarantee both DC-side voltages with very lowripple and sinusoidal generator currents.

The proposed circuit is application for each power generation unit.

Firstly, six conventional single-phase rectifiers are connected in series at DC-sideterminals, to achieving a DC-voltage with high mean value and very low ripple.

The power factor of each single-phase rectifier is corrected by an effective passivetechnique.

After correction, AC-side generatorcurrents practically become sinusoidal.

To improve the efficiency of the proposed rectifier, an electronic resistance emulatorcircuit is introduced .

The results of numerical simulations, referred to both conventional and the proposed

rectifier and performed by using Pspice on a case-study of about 1.5 MW active power .


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There has been research to utilising (water velocities)marine currentenergy for power generation.

Water turbines work on the same principle as wind turbines by using

the kinetic energy of water velocities and transferring it into usefulrotational and electrical energy.

The velocities of the currents are lower than the wind, so smalleramount of power generated.

For optimize electrical power generation, power electronic converters

are inserted between generators and loads; Power converters specifically designed to improve electrical power

generation from marine currents, improving plant reliability andflexibility, quality of generated voltages and currents and circuitefficiency.


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consists of twin axial flow rotors of

15m to 20m in diameter, each

driving a generator via a gearbox .

The twin power units of each system

are mounted on wing -like extensions

either side of a tubular steel monopile

some 3m in diameter which is set into

a hole drilled into the seabed.


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In order to optimize the electrical power generation, a powerelectronic converter connect in between the marine current generatorto load.


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conventional three-phase diode rectifier has very good efficiency,generator currents are of a very poor quality with a high THD value .

the DC side voltage has a low mean value and, and current has a highmean value and causes transmission losses;

the conventional three-phase diode

Rectifier replaced, a new circuit, in

order to obtain both sinusoidal

current generated by generators and

DC-voltage with high mean value

and very low ripple.


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The new rectifier with passive PF correction shows very good

generator current, with low THD value, together with a DC sidevoltage with a high mean value and low DC side transmission losses.

The circuit efficiency decreases because of losses on PF correctionresistor;


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The DC-side terminals of each single-phase rectifier results resistiveand equal to,

To minimize power losses on PF corrector circuit, the resistor R* canbe substituted by a resistance emulator circuit, RE.

The resistance emulator absorbs, at its terminals, the same power, P*,

absorbed by R*; and the absorbed power, is given back to the DC

-link.


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The new rectifier with PF correction and resistance emulator circuit

good generator current waveforms, with low THD value, with a DCside voltage with a high mean value and low DC side transmissionlosses;

Further, the substitution of the PF correction resistor by theresistance emulator circuit, improve the circuit efficiency.

that practically applicable to three phase diode rectifier


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SIMULATION RESULTS FOR THE PROPOSED CIRCUIT


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Modern power generation units from marine currents can be improvedby utilizing power electronicconverter specially designed.

The proposed rectifier, with passive PF correction, makes generatorcurrents quasi sinusoidal, by avoiding additional power losses andoscillating torques on generator and turbine boards;

Furthermore, the DC side voltage results with high quality waveform

and very high mean value, so minimizing transmission losses.

The circuit efficiency can be improved by introducing a resistanceemulatorcircuit.


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[1] P. Pejovic: Two three-phase high power factor rectifiers that apply the third harmoniccurrent injection and passive resistance emulation. IEEE Trans. on industrial electronics, vol.47, n. 2, Apr. 2000.[2] http://www.marineturbines.com/projects.htm[3] R. Carbone, A. Scappatura: "A high efficiency power factor corrector for single phase bridgediode rectifier". IEEE Conf. PESC 04, June 2004, Aachen, Germany.

[4] R. Carbone, P. Corsonello, A. Scappatura: A Three-Phase Diode Rectifier With Low CurrentHarmonics. ICIT 2003, 10-12 Dec. 2003, Maribor, Slovenia.[5] R. Carbone, A. Scappatura: A Comparative Analysis of Passive Power Factor Correctors ForThree-Phase Rectifiers. 4th IASTED Intern. Conf. EUROPES 2004,June, 2004 Rodhes, Greece.[6] R. Carbone, A. Scappatura: "A High Power PWM Adjustable Speed Drive with Low CurrentHarmonics ". IEEE Conf. ISIE 05, June, 2005, Dubrovnik, Croatia.

[7] R. Carbone, A. Scappatura: "An Improved Three-phase Rectifier for PWM Adjustable SpeedDrives with Passive Power Factor Correction and Resistance emulation". WSEAS Transactions onCircuits and Systems, Issue 8,Vol.4, August 2005, ISSN: 1109-2734, pp. 952-959.[8] G. Lacopo, under guide of R. Carbone: Un sistema elettronico innovativo per lagenerazione di energia elettrica dalle correnti marine. Degree dissertation, UniversityMediterranea of Reggio Calabria (Italy), Faculty of engineering.


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A High Performance Rectifier

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