single phase to three phase system using dual boost ... phase to three phase...1m.e student,...

International Journal of Advance Engineering and Research Development

Volume 3, Issue 10, October -2016

@IJAERD-2016, All rights Reserved 116

Scientific Journal of Impact Factor (SJIF): 4.14 e-ISSN (O): 2348-4470 p-ISSN (P): 2348-6406

Single Phase to Three Phase System Using Dual Boost Converter to Drive

Induction Motor Along With Active Power Factor Correction Technique

Yuvraj U. Rathod1, Mrs. M. R. Bachawad2

1M.E student, Electrical engineering department, Government College of engineering, Aurangabad, India. 2Associate Professor, Electrical engineering department, Government College of engineering, Aurangabad, India.

Abstract —This paper offerings a single-phase to three-phase drive system composed of dual boost converter, three

phase PWM inverter plus an Induction motor. It gives comparisons between boost and dual boost converter topology.

The proposed system permits enhancements of power factor and sinusoidal input current at the terminal of single phase

source by using current control mode with speed control of three phase induction motor using v/f method. Such a single

phase to three phase conversion technique has large range of application from rural area to industrial area where three

phase machines work easily on available single phase suppl. Finally a MATLAB simulation based model is developed for single phase to three phase system and simulation results are present

Keywords- Average current control mode, Boost converter, Dual boost converter, Induction motor, Power factor,

Rectifier, THD, SPWM

I. INTRODUCTION

Traditionally, conversion of single phase to three phase system conversion has been done by various ways of

switching processes with the help of power electronics devices. It is somewhat common to have only a single phase

power grid in domestic, commercial, manufacturing, and mainly in urban regions; however the variable speed drives may

entreaty a three phase power grid. Single-phase to three-phase AC to DC to AC conversion usually employs a full bridge

topology, which implicates many power switches, such a converter is represented here as conventional topology. As conversion system includes various stages of conversion processes that defines distortion and generate harmonics on

source line and load in system hence the input power factor become poor [1]. Now development in technologies causes

various power factor improvement techniques are employed to overcome these power quality problems some of which

the boost converter topology has been extensively used in various conversion applications [2]. Such that now a days AC

to DC power supplies with power-factor correction (PFC) techniques is almost entirely implemented with boost

topology, usually boost topology does not provide permissible value of higher power factor. So to overcome this

problem, Dual Boost converter technique can be employed to overcome the performance of input characteristic of current

and used to improve input power factor and reduces distortion in input current waveform. [3]. In this paper, a single-

phase to three-phase drive system composed of single-phase rectifiers along with dual boost converter to give boost

output to three phase inverter to drive three phase induction motor along with speed control by using V/F method is

proposed. The proposed system is perceived to operate where the single-phase utility grid is the unique option available.

As Compared to the conventional topology, the proposed system permits to reduce distortion in input currents and the total harmonic distortion (THD) of the system to increase fault tolerance of the system

II. PROPOSED SYSTEM AND BLOCK DIAGRAM

The block diagram showing schematic arrangement of single phase to three phase converter using dual boost

topology to drive induction motor

Fig. 1 Block diagram of implemented scheme

International Journal of Advance Engineering and Research Development (IJAERD) Volume 3, Issue 10, October -2016, e-ISSN: 2348 - 4470, print-ISSN: 2348-6406


Here, schematic arrangement of proposed technique can be divided into two parts such as source of AC link to

DC link conversion and DC link to AC link conversion. So Part 1 composed of an input supply along with line filter to

reduce input harmonics and to make superior input current waveform, a single-phase uncontrolled diode rectifier is used

here to convert AC link into DC link, to increase output of AC/DC converter dual boost topology is used with an active

power factor correction stage using the principle of current control mode technique to maintain power factor up to unity.

Also Part 2 consisting Sinusoidal PWM inverter to convert DC into AC three phase links along with constant V/F

topology to control speed of three phase induction motor using V/F speed control technique [1], [2], [3]

III. DEVELOPMENT OF PROPOSED SYSTEM

3.1 Boost topology

The part of converter consisting of boost chopper termed as Boos converter. Generally boost topology served

two functions such as 1) it controls the line current to be sinusoidal at unity power factor and 2) boost converter is needed

to efficiently convert DC voltage from lower level to higher level [5]

As to reduce losses and converter output is depend on duty cycle their relations are as follows

)1( D

VV s

o

(1)

T

tD on

(2)

The peak to peak ripple current of inductor L is given as

fLVa

VsVoVsI

)( (3)

The peak to peak ripple voltage of capacitor is given as

VofC

VsVoIoVc

)( (4)

The value of inductance respectively the capacitance C of converter are calculated at the boundary operation condition of

the circuit as fallows

f

DRDL

2

)1( (5)

fR

DC

2 (6)

3.2 Principal of control

A dc-dc converter must provide a regulated output voltage DC link under variable load and input voltage conditions.

The converter component values are also varying with temperature, time and pressure. Hence, the control of the output

voltage should be performed in a closed-loop mode using principles of negative feedback system. The two most common

closed-loop control methods for PWM dc-dc converters, namely, the voltage-mode control and the current-mode [2], [3],

[5]

3.2.1 Voltage Mode Control

In this control mode converter technique output voltage of system is controlled and feedback through a resistive

voltage divider. It is compared in a voltage error amplifier with a precision external reference voltage (Vref). The error

amplifier produces a control voltage that is compared with constant amplitude of saw tooth waveform. The comparator or

the PWM Modulator produces a PWM signal that is fed to controlled switches, which is in the dc-dc converter. The duty

ratio of the PWM signal depends on the value of the control voltage [2], [3], [5]



Fig. 2 principal of voltage mode control

3.2.2 Current Mode Control

Main objective of this implemented scheme is intensive on Current Mode Control. In this mode of control as shown

in fig., That Signals in current waveform has benefit over voltage signals. Voltage being gathering of flux, which is then

slow in time as far as control strategy, is concerned, this led to the development of a new expanse in switch mode power

supply scheme using mode of current Control. Hence, the average or peak current is employed in the feedback system of

the switch mode power converters. It has given new possibilities of analysis and at same time introduced complexities in

terms of multiple loops. [2], [3], [5]

Fig. 3 Principal of current mode control

3.3 Single phase rectifier circuit with boost topology

In this implemented scheme, the converter consist of uncontrolled diode rectifier is coupled with boost chopper

which is eighter of boost type or dual boost type converter

3.3.1 Single phase rectifier circuit with boost converter

The main principle that energies the boost converter is the tendency of an inductor to resist changes in current, when

being charged it act as a load and absorbs energy as like a resistor. When being discharged it acts as energy source as like a battery. The voltage is creates during the discharge phase is depend on the rate at which change of current and also not

on the original charging voltage, thus allowing different input and output voltages.



Fig. 4 boost converter

Fig. 5 On and Off states of a boost rectifier

The input current i(t) is controlled by changing the conduction state of transistor. As transistor is in switching mode by applying suitable firing pulse sequence, hence the waveform of the source side current can be controlled to

follow a sinusoidal reference which can be observed in the positive half wave. The ON and OFF state of switching

periods of the transistor generates an increase and decrease in the inductor current IL [1], [2], [3]

Fig. 6 THD of system using Boost topology (THD=10.71%)

As, it can be clearly seen from fig. 3.2.2 that the higher order harmonics are significantly lowered in the line

current by using a boost converter [1], [2]



Fig. 7 Power Factor of system using Boost topology (P.F=0.989)

In case of boost converter due to its simplified structure it is more capable for the power applications of low to

medium range. However, it has a very slow dynamic response and power factor correction. [3]

3.3.2 Single phase rectifier circuit with dual boost converter

To avoid low dynamic response and power factor correction issue, two converters can be connected in Parallel to

form the parallel PFC scheme i.e. dual boost converter. In case of above proposed system power from the ac source to

load flows through two parallel paths. The main path is a rectifier, in which power is not managed double for PFC,

whereas the other path processes the input power twice for PFC purpose. To achieve both output voltage regulation and

unity power factor, only the difference is, there is need to process dually between the input power and output power.

Hence, high efficiency can be obtained by this technique

Fig. 8 Dual Boost converter

Here, we use a parallel scheme, in that choke (Lb1) and switch (Tb1) are for main PFC while choke (Lb2) and

switch (Tb2) are for active filtering. The filtering circuit aids two purposes i.e. it not only improves the quality of line

current but also reduces the PFC total switching loss. The decrease in switching losses arises due to variable values of

switching frequency and current amplitude for the mode of two switches. The comparable connection of switch mode

converter is a well acknowledged strategy. It involves phase shifting of two or more boost converters operating at the

same witching frequency which is connected in parallel [3]



Fig. 9 THD of system using Boost topology (THD=8.91%)

Fig. 10 Power Factor of system using Boost topology (P.F=0.992%)

3.4 Inverter Circuit Topology

Inverter circuit is used for converting the DC quantity into the AC quantity. In proposed technique three phase SPWM

inverter, is used to convert DC output of dual boost converter into three phase AC voltage for the speed control of three

phase induction motor using V/F method. Here an SPWM controller is used to drive the gate of the switches used in the

inverter. By proper switching and control technique, inverter generates required voltage or frequencies. There are single phase and three phase inverters but the three-phase inverters are more regularly used in high power applications. This

inverter consists of three half-bridge units; the switching devices can be IGBTs, BJTs, and GTOs. Fig. 3.3.0 shows the

inverter circuit. The controlling of switches depends on the required frequency and desired power. When upper switch is

turned on the corresponding lower switch should turn off and vice versa.



Fig. 11 PWM Simulink

In case of 3-ph inverters of six modes of operation gating pulses are delayed by 120 degrees are possible for each

cycle and has interval of 60 degrees. Therefore 3-ph voltages lag behind by phase shift of 120 degrees. The inverter

output is a square waveform when it is not connected to a load and such a square shape waveform can be converted into

sine waveform by using LC low pass filter [4].

3.4.1 SPWM Controlled Technique

In case of PWM mechanism topology, the output voltage is controlled by varying the width of pulses, if there are P-pulse

per half cycle, the maximum pulse width is π/P. It is possible to choose the width of pulses in such way that certain harmonics could be eliminated. There are many methods of obtaining pulse with different widths. The most common one technique is the

sinusoidal pulse-width modulation (SPWM) topology. In this technique, the pulse width are generated by comparing a

triangular voltage Vr of amplitude A, and frequency fr with a carrier half sinusoidal voltage Vc of variable amplitude Ac and

frequency of fs [4]

Fig. 12 SPWM Controlled Technique

Here, above figure shows control strategy the reference wave is compared with the carrier wave so the gate pulse is

generated after the comparator operation. The output of comparator is fed to the Arm 1 of bridge inverter.

Fig. 13 PWM carrier wave comparison

Figure 13 shows the waveform of signal obtain from SPWM achieved by Matlab/Simulink model and respective

gate pulse. The Amplitude modulation index is defined as



cr

ma

V

VM

(7)

Where,

Vm - peak amplitude of the reference voltage waveform

Vcr - peak amplitude of the triangular voltage waveform

The output voltage is controlled by changing the modulation index M from 0 to 1.

3.5 Induction Motor drive

Induction motor is an electrical to mechanical conservation device and it is an asynchronous AC machine because

the rotor speed is always less than stator magnetic speed. The construction of IM is rugged. Hence, Induction motors are

the most commonly used due to their reliability, low cost and robustness. However, induction motors do not integrally

have the ability of variable speed operation. Due to this reason, earlier dc motors were applied in most of the electrical

drive system, But the recent developments in speed control methods of the induction motor have led to the place where in

large scale use in almost all electrical drives application. [1], [5]. Out of the several methods of speed control of an

induction such as frequency variation, variable rotor resistance pole changing, variable stator voltage, slip recovery

method, constant V/f control, etc. the closed loop constant V/f control speed techniques most commonly used. In this

method, By applying V/f ratio constant which in turn maintaining the maximum torque remains unchanged by taking the

magnetizing flux constant. Thus, the motor is completely utilized in this method. Hence it is widely used in much application like in elevator, water pumping system and in industry [1], [5]

IV. SIMULATION RESULTS AND DISCUSSION

This paper involves simulation of Single Phase To Three Phase System Using Dual Boost Converter To Drive

Induction Motor Along With Active Power Factor Correction Technique circuits and the analysis of the current and

voltage waveforms.

It starts with simple circuits with a gradual increase in complexity by initialization of new constituents and their

consequent effect on the current and voltage waveforms. In this proposed technique we focused on the moto of

improving the input current waveform i.e. making it sinusoidal by tuning the circuits along with maintaining power factor

unity and then with the help of SPWM circuit converter DC dual boost DC link into three phase AC link to drive

induction motor along with their speed control using V/F method. All the simulation work is done in MATLAB Simulink simulation of proposed conversion system

Fig. 14 system model using MATLAB Simulink

The proposed system shown in figure 14 is designed and simulated with the help of tool i.e. MATLAB. In that it consisting of various stages involving AC- to DC link conversion with the help of uncontrolled rectifier

and then feed it into Dual boost topology where the DC link become boosted from lower voltage to higher level

and is given to then PWM inverter. Here Boosted DC link to AC link is done and it given to induction motor for

speed control using V/F topology



4.1 simulation Single phase rectifier circuit with dual boost converter

Here, two converters can be connected in Parallel to avoid low dynamic response and power factor correction issue,

hence form the parallel PFC scheme i.e. dual boost converter. Here, power from the source of AC to the load flows

through bi-parallel lanes. The main path is a rectifier, in which power is not handled dually for PFC, whereas the other

path possess the input power dually boosted for PFC purpose, to achieve both output voltage regulation and unity power

factor.

Simulation result showed in figure 15, 16 & 17 consisting of source waveform along with power factor and

output of dual boost converter.

Fig. 15 sinusoidal waveform of input current and voltage

Fig. 16 waveform of power factor



Fig. 17 waveform of output of dual boost converter

4.2 Inverter Circuit Topology

Inverter circuit is used for converting the DC quantity into the AC quantity. In this proposed technique three phase

SPWM inverter is used to convert DC output of dual boost converter into three phase AC voltage for the speed control of

three phase induction motor using V/F technique. Simulation result shown in following graph 4.2.3 consisting of output of SPWM and rotor speed of three phase induction motor

Fig. 18 waveform of three phase current of PWM

Fig. 19 waveform of three phase voltage of PWM



Fig. 20 waveform of rotor speed of three phase induction motor

4.5 Analysis of power factor and thd along with output of boost topology

Sr. No. Circuit topology Power factor THD Output Voltage

1 Boost Converter 0.989 10.71 324

2 Dual Boost Converter 0.992 8.91 415

Table 1.analysist of P.F, THD & output voltage

4.6 Analysis of speed control of i.m. using v/f topology

Sr. No. Frequency(Hz) Speed (rpm)

1 30 Hz 896.5 rpm

2 40 Hz 1198 rpm

3 50 Hz 1493 rpm

Table 2.analysist of frequency & speed

4.7 APPENDIX

Boost converter specification Inductor=0.230H, Capacitor=1.85 µf

Three phase induction motor

specification

1 H.P, 400V, 50Hz, 4 pole , 1440 rpm

Stator & rotor resistance =2Ω & 1.9 Ω

Stator & rotor inductance = 0.0230H,

Mutual inductance= Moment of

inertia=0.02 kg.m2

Table 3 parameters of system

V. CONCLUSION

In this paper The Power Factor Correction with different converters are simulated with MATLAB Simulink.

Paper shown and discussed on result of Boost converter using Current Mode Control and Dual Boost Converter using

Current Mode Control technique, it is noticed that the Power Factor is better for Dual Boost Converter Circuit. Also it is

noticed that THD is less for Dual Boost Converter.

Here output of dual boost converter fed to SPWM inverter further is utilised to drive Induction motor to speed

control. In constant V/F control topology, with the help of PWM inverter, we can vary the supply voltage as well as

frequency such that the ratio V/F remains constant so that the flux remains same. So we can get different operating zone

for various speeds and torques and also we can get various synchronous speeds with almost same maximum torque. Thus the motor is completely utilized and also we have a good range of speed control



REFERENCES

[1] Pradeep M Patil, Sanjay L Kurkute, “Speed control of three phase induction motor using single phase supply

along with active power factor correction,” ACSE Journal, Volume (6), Issue (3), Oct. , 2006

[2] Sudhakar babu, Dr.G. V. Siva Krishna Rao, “Simulation of Active power factor correction using boost type

converter” IJSETR Journal, volume 3, issue 10, October 2014

[3] P .Vijaya Prasuna, J.V.G. Rama Rao, Ch. M. Lakshmi, “Improvement in Power Factor & THD Using Dual

Boost Converter,” IJERA journal, Vol. 2, Issue4, July-August 2012, pp.2368-2376

[4] Mohammad H Rashid, “power electronics Handbook” (Academic press, 2001).

[5] Bimal K. Bose, “Modern power electronics and AC drives”, ISBN-978-81-203-2749-8

single phase to three phase system using dual boost ... phase to three phase...1m.e student,...

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