© 2019 JETIR June 2019, Volume 6, Issue 6 …non-linearity of the system increased and complexity in control is major issues. As power system is integration of generation, transmission

© 2019 JETIR June 2019, Volume 6, Issue 6 www.jetir.org (ISSN-2349-5162)

JETIR1908B11 Journal of Emerging Technologies and Innovative Research (JETIR) www.jetir.org 74

D-STATCOM based Distributed Generation

Systems for Power Quality Improvement 1Indra Mohan Joshi, 2Anurag S D Rai, 3Reeta Pawar

1Research Scholar Mtech. Power Systems, 2,4Assistant Professor, 3Professor 1,2,3Department of Electrical and Electronics Engineering,

1,2,3 Rabindranath Tagore University, Bhopal-Chiklod Road, Raisen-464993(M.P)

ABSTRACT: Power quality is a major concern for electrical engineers and researchers in the present scenario.

Various power quality problems are voltage sag, swell, interruptions and harmonics etc. This paper discussed the

problem of harmonics and its reduction in distribution network against the induction motor drive load. Harmonic

distortions have been reduced using Distribution static compensator (DSTATCOM) modelling in the MATLAB/

SIMULINK environment. The simulated results show the effectiveness of DSTATCOM in reducing harmonics

distortion when connected in network.

KEYWORDS: D-STATCOM, PWM, STATCOM, SVPWM.

I. INTRODUCTION

Power system when incepted is simple to operate and control. With increase in interconnection and size of system

non-linearity of the system increased and complexity in control is major issues. As power system is integration

of generation, transmission and distribution of the power produced, providing quality power is one of the major

issues in present perspective. To provide power with specific rating and standards with end users compensators

are required to filter the power distortions, hence shunt, series and combinational controllers are required for

maintainace of active power, reactive power, uniform voltage profile and power factor. Compensators are

working in two methodologies having power spinning reserve for systems voltage and reactive power

compensation and without reserves direct compensation with utility of capacitors.

II. FOURIER SERIES AND ANALYSIS

The Fourier analysis of the harmonics for output power and power factor is known as Total Harmonic

Distortion (THD). It is done with the help of FFT analysis and based on the result the given system can be

justified. The THD is the analysis of the whole power system that the system is persistent to harmonics and fast

response to remove it.

The Fourier series is the periodic function of non-sinusoidal waveform given by f (t) and can be expressed

as:

𝑓(𝑡) = 𝐹𝑜 + ∑ 𝑓𝑘(𝑡)∞𝑘=1 .….……… 3.1

𝑓(𝑡) = 1

2𝑎𝑜 + ∑ {𝑎𝑘 cos(𝑘𝜔𝑡) + 𝑏𝑘 sin (𝑘𝜔𝑡)}∞

𝑘=1 ……….… 3.2

where f (t) is periodic function of non-sinusoidal waveform

𝐹𝑜 =1

2𝑎𝑜 is the average value of the function f(t)

𝑎𝑜 =1

2𝜋∫ 𝑓(𝑡)𝑑𝜔𝑡

2𝜋

0 …….…… 3.3

𝜔 =2𝜋

𝑇 is the angular velocity

𝑇 = 1

𝑓 is the periodic interval of time.

where f is the fundamental frequency.

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𝑎𝑘 = 1

𝜋∫ 𝑓(𝑡) cos(𝑘𝜔𝑡) 𝑑𝜔𝑡

2𝜋

0 ; 𝑘 = 1,2,3 ………….. 3.4 𝑏𝑘 =

1

𝜋∫ 𝑓(𝑡) sin(𝑘𝜔𝑡) 𝑑𝜔𝑡 ; 𝑘 = 1,2,3

2𝜋

0 ………….. 3.5

where 𝑎𝑘 and 𝑏𝑘 are the Fourier coefficients.

In three - phase Distribution Generation System (DGS) the distorted waveform is contains the harmonic

current which contains multiple integer of fundamental frequency. A purely sinusoidal waveform does not contain

harmonics.

A. Distributed Generation System

According to Ministry of New Renewable Energy (MNRE) the Distributed Generation systems in our India in

the recent session 2013-14 tabulated below:

Table 1 Distributed Generation systems Installed Capacity in India (2013-2014)

Sector Target Achievements

during the

month of May

Achievements during the

month of May

Cumulative

Achievements

2013-

2014

2014 -

2015

2013-

2014

2014-

2015

2013-2014

(% of

target)

2014-2015

(% of

target)

(as on

31/05/13)

(as on

31/05/14)

I. GRID – INTERACTIVE POWER (CAPACITIES IN MW)

Wind Power 2500.00 2000.00 114.30 53.05 264.10

(10.56)

130.15 (6.51) 19317.05 21262.23

Small Hydro Power 300.00 250.00 24.00 - 39.00

(13.00)

- 3671.25 3803.65

Biomass Power &

Gasification

105.00 100.00 - - - - 1264.80 1365.20

Bagasse Cogeneration 300.00 300.00 - - - - 2337.43 2648.35

Waste to Power 20.00 20.00 - - - - 96.08 106.58

Solar Power 1100.00 1100.00 73.0 - 73.00 (-) - 1759.44 2647.00

Total 4325.00 3770.00 211.30 53.05 376.10 (8.7) 130.15 (3.45) 28446.05 31833.01

II. OFF- GRID / CAPTIVE POWER (CAPACITIES IN MWEQ)

Waste to Energy 10.00 10.00 - - - - 115.57 132.73

Biomass (non –

bagasse) Cogeneration

80.00 80.00 2.80 - 2.8 (3.5) - 473.95 531.82

Biomass Gasifiers –

Rural

1.00 0.80 - - - - 16.79 17.48

- Industrial 9.00 8.00 0.5 - 0.5 (5.6) - 142.08 147.20

Aero-Generators /

Hybrid systems

1.00 0.05 - - - - 2.11 2.25

SPV Systems 40.00 60.00 - - - - 124.67 174.35

Water mills / micro

hydel

2.00

(500

nos)

4.00 (500

nos)

- - - - 10.65

(1231 nos)

13.21

(2643

nos)




The harmonic current is the multiple integer of the fundamental frequency according to the harmonics

present in the three phase converter connected to the DGS, harmonics frequency will be as shown in the following

table 2

Table 2. Order of Harmonic Pulses and their Frequencies

Order Of Harmonic

(k)

Rectifier Pulse Number Harmonic Base frequency

(fh =fn*k) 6 12 18 24

5 Y 250

7 Y 350

11 Y Y 550

13 Y Y 650

17 Y Y 850

19 Y Y 950

23 Y Y Y 1150

fn = 50 Hz is the fundamental frequency

III. MODEL DESCRIPTION

The simulated model of the 4-bus distributed generation system is shown in figure 1. In this model the supply is

given by 3-phase programmable voltage source in which phase and frequency can be pre-programmed. In this

test system the supply is 415v, 50Hz and at phase angle of 0 deg is supplied to the primary (source) bus 1.

Bio-gas based energy

system

2.00 - - - - - - 3.77

Total 143.00 158.85 3.30 0.00 3.30 (9.06) 0.00 885.82 1022.81

III. OTHER RENEWABLE ENERGY SYSTEMS

Family Biogas Plants

(in Lakhs)

1.10 1.10 - - - - 46.55 47.40

Solar Water Heating –

Coll. Areas (million

m2)

0.60 0.50 - - - - 0.05

(10)

6.98




Figure 1. Four Bus Distribution Generation System, Simulink model

IV. RESULT ANALYSIS

In the above model the testing and simulation is done for the distributed generation system by the application of

the space vector technology. The voltage is able to maintain constant throughout the waveform even after the

injection of harmonics at the supply and also on the point of common coupling. The result obtained in the result

analysis is compared with result of the previous research as shown in the figure 4.20 and figure 4.21[1]. It is

interpreted that by the introduction of the space vector technique in the D-STATCOM the results are improved

and current harmonics are reduced to an appreciable level. The current waveform is smooth shown in figure 4.13

when compared with figure 4.21. It is also improved than current waveform at the point of common coupling

shown in figure 4.15.




Figure Error! No text of specified style in document.:1 Output voltage waveform of Distributed Line

Figure Error! No text of specified style in document.:2 Output current waveform of Distributed Line

It is also observed that the output voltage waveform contains very less harmonics. It is calculated by FFT

analysis. The input signal is taken as voltage at fundamental frequency of 50Hz is 312.5 V generates the THD

of 1.68%.




Figure Error! No text of specified style in document.:3 THD Response of the Output Signal for 2 cycles of Time Period

V. CONCLUSION

In this research the simulation is done to the new developed test model of distributed generation system that is

controlled with the help of D-STATCOM in conjunction with the DG set.D-STATCOM effect in power

networking and power quality analysis were evaluated, meanwhile research on simulation were going on to know

each impact of the controller.

VI. REFRENCES

[1] Demirok E., Sera D., Teodorescu R., Rodriguez P., and Borup U. – ‘Evaluation of the voltage support

strategies for the low voltage grid connected PV generators’ - in Proc. IEEE Energy Convers. Congr.

Expo, 2010, pp. 710–717.

[2] Dugan R. C., Mc Granaghan M. F. – ‘Electrical Power Systems Quality’- 2nd Edition, McGraw-Hill,

2002.

[3] EN 50160 Standard – ‘Voltage Characteristic of Electricity Supplied by Public Distribution Systems’.

[4] Fujita H. and Akagi H. – ‘Voltage-regulation performance of a shunt active filter intended for installation

on a power distribution system’ - IEEE Trans. Power Electron, Vol. 22, No. 3, May 2007, pp. 1046–1053.

[5] Gupta R., Ghosh A., and Joshi A. –‘Multiband hysteresis modulation and switching characterization for

sliding-mode-controlled cascaded multilevel inverter’ - IEEE Trans. Ind. Electron, Vol. 57, No. 7, pp.

2344–2353, Jul. 2010.

[6] Gyugyi L., “A unified power flow control concept for flexible ac transmission systems,” Proc. Inst. Elect.

Eng., Vol. 139, No. 4, pp. 323–331, Jul. 1992.

[7] Hingorani N. G. and Gyugyi, L. “Understanding FACTS: Concepts and Technology of Flexible AC

Transmission Systems. New York: Wiley, 1999.




[8] IEC 61000-1-4 Standard – ‘Rationale for Limiting Power –Frequency Conducted Harmonic and Inter-

harmonic Current Emission from Equipment, in the Frequency Range up to 9kHz’ - Electromagnetic

Compatibility (EMC).

[9] Jouanne A.V. and Banerjee B. – ‘Assessment of voltage unbalance’ - IEEE Trans. Power Del., Vol. 16,

No. 4, Oct. 2001, pp. 782–790.

[10] Lee T.L., Hu S.-H., and Chan Y.H. – ‘Design of D-STATCOM for voltage regulation in microgrids’

- in Proc. IEEE Energy Convers. Congr. Expo., 2010, pp. 3456–3463.

[11] Anurag S D Rai, Reeta Pawar, Durga Sharma, Shaurabh Sen, Sanjeev Kumar Gupta, "Algorithms for

synchrophasor enabled digital relay in differential protection scheme", proceedings of international

conference on recent advancement on computer and communication, lecture notes in networks and

systems 34, https://doi.org/10.1007/978-981-10-8198-9_4, book id: 448040_1_en, book isbn: 978-981-

10-8197-22018, springer nature singapore pte ltd.

[12] Anurag S D Rai, Kamal Shakya, etal, “HVDC Rectifier Station Modelling using PSCAD-EMTDC”,

HCTL Open International Journal of Technology Innovations and Research (IJTIR), Volume 21, Issue

1, July 2016, e-ISSN: 2321-1814, ISBN (Print): 978-81-932623-1-3.

[13] Anurag S D Rai, Lovesh B Xaxa, Prakhar Singh Bhadoria, Ankita Tiwari, “Topologies of FACTS

controllers and their adaptation issues”, International Journal of Science and Research, ISSN (Online):

2319-7064, Vol. 04 Issue 5, May 2015.

[14] Anurag S D Rai, “Modeling of Relay by PSCAD/EMTDC for use in Power System Protection Studies”,

National Seminar on Prospects and Challenges of Electrical Power Industry in India, ISBN 978-93-

84743-43-7 © 2015 Bonfring, page no 404-4087, February 11-12, 2015.


https://doi.org/10.1007/978-981-10-8198-9_4

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© 2019 JETIR June 2019, Volume 6, Issue 6 …non-linearity of the system increased and complexity in control is major issues. As power system is integration of generation, transmission