Single Phase To Three Phase Converter Engineering Essay

Single Phase To Three Phase Converter Engineering Essay

Several solutions have been proposed where the aim is to cut down harmonic deformations in a generating system. It is now the renewable power use that is turning more, therefore a little graduated table Wind Energy Conversion System is concentrated which needs harmonic decrease. The air current energy unit that we are be aftering to put in is individual stage so we go for a individual stage to three stage ac-dc-ac convertor planing to cut down harmonics. Parallel convertors have been used to better the power capableness, dependability, efficiency, and redundancy. Normally the operation of convertors in parallel requires a transformer for isolation. Here a single-phase to three-phase thrust system composed of two parallel single-phase rectifiers and a three-phase inverter is proposed. Compared to the conventional topology, the proposed system permits: to cut down the rectifier switch currents ; the entire harmonic deformation ( THD ) of the grid current with same exchanging frequence or the switching frequence with same THD of the grid current ; and to increase the mistake tolerance features. Besides the loss of the proposed system is lower. The aforesaid benefits justify the initial investing of the proposed system, due to the addition of figure of switches.

Index Terms- Converters, IGBT, MOSFET, Renewable Energy, Single Phase to Three Phase, Wind Energy.

Introduction

The paper trades with the sweetening of the use of renewable energy and betterment of its public-service corporation. Wind energy is one of the most promising alternate energy engineerings of the hereafter. Throughout recent old ages, the sum of energy produced by wind-driven turbines has increased exponentially due to important discoveries in turbine engineerings, doing wind power economically compatible with conventional beginnings of energy.

One of the restrictions of air current energy is Harmonic deformation that hinders the public-service corporation of the air current coevals. Harmonics is referred as the perturbation or the impairment of the pureness of current or electromotive force after undergoing several alterations or transmutations. Since power quality is really of import it is compulsory to detect methods to cut down harmonics and retain pureness. As disciplinary action is ever expensive and unpopular solution more idea and investing are devoted at the design phase on the footing that bar is better than remedy.

The beginnings of harmonics can be divided into 3 classs:

Large Numberss of distributed non-linear constituents of little evaluation.

Large and continuously indiscriminately changing non-linear tonss.

Large inactive power convertors and transmittal system flat power electronics devices.

Harmonicss Reduction Technique

In general there are many techniques to cut down harmonics like

use of harmonic filters [ 13 ]

PWM technique [ 4 ] , [ 5 ] , [ 13 ]

Filter is a device that is designed to stamp down harmonic current and electromotive forces from being injected into the power system since these causes damaging effects to the devices being used in the system. The harmful and detrimental effects of harmonic deformation can be avoided by the use of filters. There can be two types of filters that are used in order to cut down the harmonics deformation i.e. the active filters and the inactive filters. Active harmonic filters are electronic devices that eliminate the unwanted harmonics on the web by infixing negative harmonics into the web. The active filters are usually available for low electromotive force webs.

In order to command power and reactive power, it is indispensable to command the magnitude and stage angle of the injected electromotive force by the convertor [ 1 ] , [ 4 ] , [ 5 ] , [ 7 ] . At the same clip, it is desirable to modulate the DC coach electromotive force. Another demand is to minimise the injection of the lower order harmonics by the convertor. The pulse breadth transition ( PWM ) is utilised to accomplish the undermentioned aims:

To command the end product AC electromotive force for a changeless DC electromotive force.

To minimise the harmonics subject to the restraints on the shift losingss, coevals of noise etc.

Circuit Design

The undertaking deals with a convertor design as an effort to cut down harmonic deformations in air current energy transition system. We design a convertor circuit for a individual stage –

three stage transition with two individual stage rectifiers connected in analogue and a three stage inverter. The experiment is simulated utilizing MATLAB Simulink package and the consequences are compared for the effectivity of the convertor circuit [ 9 ] . Besides the choice of switch for the convertor is really indispensable therefore we compare two different switches- MOSFET and IGBT and analyse its features for the suitableness and effectivity.

Procedure of Switch Selection

The below tabular array shows the comparing of different parametric quantities considered in the class of choice of switch for the convertor thereby assisting us to warrant our choice.

The Table below shows the comparing between different possible switches that are used in convertors. We can see the features and parametric quantities based on which the switches are selected.

Table I. Choice OF SWITCH FOR THE CONVERTER CIRCUIT

Device

Comparison country

rectifying tube rectifier

Thyristor [ SCR ]

GTO

IGBT

MOSFET

Inverter switch

Ten

Ten

AC-DC transition

Ten

Ten

Ten

Ten

Ten

Inverter types

Current beginning

Ten

Ten

Voltage beginning

Ten

Ten

Ten

Efficiency

High

High

Low

High

High

Gate control signal

Sodium

current

current

electromotive force

electromotive force

Gate current

Sodium

& A ; lt ; 2 Amperes

400-1000 Amperes

0.1 Amperes

& A ; lt ; 0.01 Amp

Voltage evaluation

High

High

High

To 1200 Volts

4000 Vs

Current evaluation

6000 Amps

5500 Amps

1000 Amps

1000 Amps

600 Amperes

Switch overing losingss

Sodium

Medium

High

Low

Low

Switch overing velocity

Sodium

Low

Low

Very high

Very High

From the comparing it is apparent that MOSFET, IGBT are the two most suited switches for the Inverter subdivision of convertor as MOSFET and IGBT showed good efficiency, electromotive force and current evaluations. Besides the exchanging velocity and shift losingss are satisfactory. And it does n’t necessitate a particular exchanging angle control mechanism. Thus the MOSFET, IGBT rectifier/inverter system is the proposed convertor for the little graduated table air current energy transition system. Besides comparing between MSOFET and IGBT operation in Single stage – Three stage transition every bit good as Three stage – Three stage transition is done.

Technology used for exchanging

The maximal accomplishable efficiency of any practical system is 0.93. However due to plan considerations and operational restraints, the per centum drastically reduces to a upper limit of 0.5, in the instance of a air current energy system. The purpose of this undertaking is to better the normal operating average efficiency of 0.29. Assorted techniques have been instrumental in cut downing the overall losingss in the system, and besides peculiar involvement is streamlined in the sphere of decrease of harmonics in the system. A batch of techniques by which, losingss, and peculiarly, harmonics can be reduced have been figured out by analysing assorted IEEE undertakings. Apart from circuit component alterations, design alterations have besides been analyzed.

The Circuit Design

Here as per the circuit diagram we can see 14 switches wholly i.e. 4 for each individual stage rectifiers and 6 for the three stage inverter. Now when the individual stage supply is given to the system the rectifiers convert the AC individual stage supply to DC supply so it is fed to the inverter for farther transition into a three stage AC supply. Here as we can see the rectifiers are connected in analogue to each other, as we know the working of the rectifier. The convertor can either utilize MOSFET as a switch or IGBT as a switch.

FIGURE 1. CIRCUIT DESING FOR SINGLE PHASE_ THREE PHSE CONVERTER

Here as per the circuit diagram we can see 14 switches wholly i.e. 4 for each individual stage rectifiers and 6 for the three stage inverter. Now when the individual stage supply is given to the system the rectifiers convert the AC individual stage supply to DC supply so it is fed to the inverter for farther transition into a three stage AC supply. Here as we can see the rectifiers are connected in analogue to each other, as we know the working of the rectifier. The convertor can either utilize MOSFET as a switch or IGBT as a switch.

Rectifier is a device that converts AC to DC signal. In a individual stage controlled rectifier there are 4 exchanging devices two in each leg. Two switches at a clip viz. alternate switches of the legs are on at a clip. Thereby change overing the AC signal into DC signal. Then it is fed to the inverter which has 6 exchanging devices two per leg, therefore a 3 stage inverter has 3 legs with 2 switches per leg. The working mechanism is about similar to the rectifiers.

Simulation utilizing MATLAB/Simulink

MOSFET Based Converter Simulation

The MATLAB simulation theoretical account clearly depicts the no of switches used, besides the parametric quantities involved in the analysis of the circuit. Simulation consequences help us clearly conclude the difference in the public presentation based analysis of MOSFET and IGBT convertors.

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FIGURE.2 MOSFET based Single stage – three stage convertor utilizing MATLAB Simulation

MATLAB is a high-ranking linguistic communication and synergistic environment for numerical calculation, visual image, and programming. Using MATLAB, you can analyse informations, develop algorithms, and create theoretical accounts and applications. The linguistic communication, tools, and constitutional math maps enable you to research multiple attacks and make a solution faster than with spreadsheets or traditional scheduling linguistic communications, such as C/C++ or Java.

Here we simulated convertor circuit with MOSFET switches and IGBT switches and compared the difference in the capacity of cut downing harmonics.

FIGURE.3 RECTIFIER OUTPUT FOR MOSFET BASED SINGLE PHASE – THREE PHASE CONVERTER USING MATLAB SIMULATION.

This graph represents the rectifier end product. The electromotive force amplitude is 310V i.e. the harmonics in the electromotive force causes spikes which reaches this value, where as the original electromotive force is about 230V. The graph is plotted for a clip period of 20 msecs. The positive half moving ridge is rectified better than the negative half moving ridge. We can clearly see the spike happening in the positive half moving ridge due to harmonics.

.

FIGURE. 4 FINAL OUTPUT OF THE MOSFET BASED CONVERTER SYSTEM USING MATLAB SIMULATION

The end product is around 220V with decreased harmonics. The inverter end product by itself has reduced harmonics deformation found in the rectifier end product. The spikes that were found in the rectifier are non present in the inverter end product wave form. From this it ‘s apparent that the individual stage to three stage electromotive force convertor design helps in cut downing the harmonics.

The MOSFET switch used is a electromotive force controlled device and has a high shift frequence that enhances the rectification every bit good as inversion of the generated electromotive force. The individual stage to three stage constellation is helpful in cut downing the harmonics is therefore proved from the graphs above.

IGBT Based Converter Simulation

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FIGURE 5: MATLAB SIMULATION DIAGRAM FOR IGBT BASED SINGLE PHASE-THREE PHASE CONVERTER

The simulation theoretical account diagram for the IGBT individual stage to three stage convertor is given supra. We can see that the topology is similar to that of the MOSFET based convertor except for that the IGBT block contains a rectifying tube connected parallel to it.

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FIGURE.6 RECTIFIER OUTPUT WAVEFORM OF IGBT BASED SINGLE PHASE – THREE PHASE CONVERTER WITH 220V Supply

This graph is the rectifier end product for a 220V input supply. In this graph the magnitude of end product is around 220V which means the input is wholly rectified. The happening of spike is at the junction of two half moving ridges. Thus the completeness of the half waves is affected by the harmonic deformations in the instance of IGBT based convertor.

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FIGURE.VII FINAL OUTPUT WAVEFORM OF THE SYSTEM WITH 220V Supply

The end product graph shows the decrease in harmonics to some extent the magnitude of harmonics is reduced and is apparent in the end product graph.

Analysis OF HAMONIC REDUCTION WITH VARIATION OF INPUT INDUCTANCE

Initially we analyzed the system effectivity for assorted input electromotive forces like 230V, 220V, 200V etc. , where we found a outstanding consequence merely for 220V input supply. Now that altering in electromotive force is non bring forthing adequate difference therefore we try to alter the input induction and recognize the effectivity of the MOSFET and IGBT based transition systems.

FIGURE. 8 GRAPHICAL REPRESENTATION OF VARIATION OF HARMONICS WITH VARIATION OF INDUCTANCE IN A MOSFET BASED SINGLE PHASE – THREE PHASE CONVERTER

In the individual stage to three stage transition topology of convertor utilizing MOSFET, the inductances L2 and L4 ( matching to the negative rhythm of supply ) are varied from 0.1 mH to 0.4 mH under a varying runing electromotive forces between 220 V and 230 V. The consequences that are therefore obtained are represented in the graph. For operating electromotive force 220 V, the end product electromotive force peak varies between 214.4 V and 206.1 V matching to the alteration in input induction values between 0.1 mH and 0.4 mH. Similarly, for operating electromotive force 230 V, the fluctuation in peak electromotive force is between 224.2 V and 215.4 V for the same alteration in input induction.

FIGURE.9 GRAPHICAL REPRESENTATION OF VARIATION OF HARMONICS WITH INDUCTANCE IN AN IGBT BASED SINGLE PHASE – THREE PHASE CONVERTER.

In the individual stage to three stage transition topology of convertor utilizing IGBT, the inductances L2 and L4 ( matching to the negative rhythm of supply ) are varied from 0.1 mH to 0.2 mH under a varying runing electromotive forces between 220 V and 230 V. The consequences that are therefore obtained are represented in the graph. For operating electromotive force 220 V, the end product electromotive force peak varies between 219.4 V and 216.5 V matching to the alteration in input induction values between 0.1 mH and 0.2 mH. Similarly, for operating electromotive force 230 V, the fluctuation in peak electromotive force is between 229.8 V and 226.3 V for the same alteration in input induction.

In the above graphs we see the fluctuation of harmonics with the fluctuation of input induction therefore taking the input induction sagely can impact the harmonics decrease procedure.

Decision

As per the above consequence and treatment we saw the fluctuation of harmonics with fluctuation of electromotive force magnitude and input induction consequently, with the consequence we observe that individual stage – three stage MOSFET based convertor reduces spikes to a great extent without any loss in the electromotive force magnitude when the input induction is of 0.1mH each. But when the induction is changed to L1, L3= 0.1mH and L2, L4=0.4mH the end product consists of negative extremums without loss in voltage magnitude.

Coming to IGBT based convertor, the individual stage – three stage convertor has low harmonics in the rectifier every bit good as the inverter outputs when the induction in L1, L3=0.1mH and L2, L4=0.2mH.when the induction is changed to 0.1mH all the rectifier end product has small heavy spike at the junction of the half moving ridges which are reduced without electromotive force loss.